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How To Search/Internet search engine list. The following list contains Internet search engines that are described in this book.

How To Search/Journal database list. The following list contains indexing and abstracting journal databases that are described in this book.

How To Search/Citation index list. The following list contains citation indexes that are described in this book.

How To Search/Other search type list. The following list contains search mechanisms that have yet to be categorized but are described in this book.

Outdoor Survival/Food. I feel that food can be divided into two categories: That which crawls, and that which sprouts. First, I'll cover plants, then I'll say some about ways to get meat. Growing, Catching, and Preparing Food - An Overview. If you are facing the prospect of gathering and / or catching food in the wild, you are facing one of two circumstances: this is a lifestyle choice, or you're in a long-term survival situation, where chances of rescue within weeks are slim. The time frame of weeks may surprise some, but the reality is that in most survival situations, food is the least important factor, i.e., if you make it your number one survival priority, you'll probably get killed by something more important like not having sought adequate shelter while you were chasing badgers with a pointy stick. But getting down to brass tacks... Chances are, you're not going to develop the skills necessary to hunt wild animals without firearms in any immediate timeframe, so the next option available to us is to prepare snares and traps. Snares and traps have the distinct advantage that they are hunting for you night and day, rain or shine. A simple circuit of your traps once a day is all that is required. The most important, and hopefully obvious consideration with traps is site selection: place traps where animals will be. Bait is fine, but to have bait, you have to have already caught something, haven't you? If you haven't, consider that animals invariably seek water, so a simple snare along a well worn path to the creek is perfect. Types of Traps: Edible & Poisonous Wild Plants. Here are some guideline for eating wild plantlife. In most situations, if you don't know what a plant is, don't eat it. You can live 3 weeks or more without food. You can live a lot less long with poison in your system. Only eat wild plants if you have devoted a good deal of time to studying them. NOTE: This technique can be very dangerous. Many plants (Agave, to name one example) contain compounds that won't burn or tingle, but can be powerful emetics and/or laxatives. Others may be safe in small quantities, but can be dangerous when large amounts are eaten. Your best bet is to familiarize yourself with a few common plants for your area that can be eaten, and not rely on potentially dangerous methods such as the one listed above. Animals. There are three main types of meat you can get in a survival situation: Insects, fish, and game. Here they are covered in that order; easiest to hardest. There are some species of toxic birds that you should not eat. Even quail can be hazardous. Don’t eat birds you have never encountered before. Most mammals are okay to eat as long as they are properly cooked. You should never eat the liver of a carnivore or omnivore. The liver can hold dangerous toxins. Do not eat dog/wolf liver, it contains high levels of vitamin A which can lead to hypervitaminosis and death. Eating a long term diet of only rabbits can lead to "rabbit starvation" and death. Rabbits have no fat which your body needs. Rabbits do have fat in their intestines, however, so eat as much of the rabbit as you can stomach. Insects. In many places, insects are a staple of local diets. Some basic guidelines for insect eating: Fish. Fish are easier to catch than wild game. It's best to go fishing in the morning and at dusk; just after sunrise and before sunset. In streams, look for deep still pools, undercut banks, and the areas around and behind sandbars. In lakes, bass gather around cover. Try areas around plantlife, sunken logs and boulders, docks, and areas around dropoffs and ledges. In the ocean, try reefs, points, deltas, and channels. Here I have listed some ways of catching fish, along with how to use these ways to catch various types of fish: Techniques. Older people have mentioned tickling the fish, then jamming your thumb into the gills for extra grip. Next Step. Now that you have a fish (or several fish) you should scale and clean them. (Instructions for scaling and cleaning to be added.) You can eat the heart and liver. Save the other organs for bait. Cut open the stomach to see what the fish has been eating, so you can get an idea of what bait to use. If the stomach is empty, it means that the fish are very hungry, and will bite almost anything. You can put the head on a large hook and drop in the water to catch a snapping turtle. Scatter whatever is left in the water to attract other fish.

Hebrew/Personal Pronouns. Grammar. In general, the "to be" verb is not present in the Hebrew language. So "He David" translates to "He is David". Or -- "She is Sarah". Exercises. Who is who? This exercise using the following extra words:<br> -- who "mi",<br> -- Hello; Goodbye "shalom"<br><br> and some names:<br> (Sarah),<br> (Jacob),<br> (Moses),<br> (Rachel)<br> Now try some simple sentences Without diacritic marks. Translate the following: Answers. See Hebrew/Personal Pronouns/Answers.

East Asian Calligraphy/Cover. East Asian Orthography. Chinese ~ Japanese ~ Korean. East Asian Calligraphy

East Asian Calligraphy. Introduction. In this textbook, brought to you cooperatively by the Korean, Japanese, and Chinese language textbooks, we hope to illustrate some principles of East Asian writing systems that apply to all three languages above. Whether we are talking about Chinese characters, Japanese kana, or Korean jamo, East Asian writing systems share many similarities, including their stroke forms, basic shapes, and character structure. Nevertheless, there are also some differences. Not all of the lessons in this textbook apply to all of the languages. Depending on the language that you are learning, you will (fortunately) be able to skip over some lessons and sections. In the following table of contents, each link is preceded by one or more letters. The letters indicate which writing system each unit applies to. The letters are:<br> Chinese characters, including Chinese hanzi, Japanese kanji, and Korean hanja<br> Japanese kana, especially hiragana<br> Korean hangul If a lesson isn't required for the language that you're learning, feel free to skip it. Note that this course is strictly focused on writing nicely and legibly, and is meant as a supplement to the Chinese, Japanese, and Korean Wikibooks. It does not teach you the actual characters / kana / hangul themselves.

Algebra/Polynomials. With practice the concept of slope for linear functions becomes intuitive. It makes sense that the line that fits the equation formula_1 has a steeper ascent then the line that fits the equation formula_2. You only have to move horizontally one unit to change your vertical direction two for the former when you graph formula_1. How many blocks do you need to move horizontally to change your vertical direction by one for the line formula_2? When we express concepts like formula_5 the abstract behavior of what is being represented becomes a little harder to see. A monomial of one variable, let's say x, is an algabraic expression of the form formula_6 where The integer formula_8 is called the degree of the monomial. The idea of a monomial of degree zero appears a bit mystical since it always represents one, except when the value of the variable is set equal to zero when the result is undefined. This idea allows us preserve the value of the constant in the monomial. We know that formula_10 is always equal to formula_7 because even though we have 0 x's (somethings) we still have a c. When x = 0 things are difficult because the value we started with, 0, represents nothing. For a monomial of power 1 we are multiplying C by one instance of our variable. When formula_12 we get formula_13. When formula_14 we are multiplying c by 1 x. If x is less than 1 then c gets smaller, if x is more than 1 c gets bigger. When x is between 0 and -1 c gets smaller slower, when x is less than -1 c gets smaller faster. A monomial with power two is one that "squares" the value of x. The reference to square is because using the multiplication operation once allows us to measure area. If you have something that is one unit on each side this is called a square unit. If you divide both sides of your square unit in half, you get 4 quarter units. We represent this with math by doing the multiplication formula_15 Squaring something is a non-intuitive operation until you become comfortable with the graph of the function. We can see this with the story of the mathematician who was offered a reward by his king. The mathematician said he wanted a single grain of wheat, squared every day for 30 days. For the first seven days the king's servants delivered 1, 2, 4, 16, 256, 65,536 grains of wheat to the mathematician. On the seventh day the value was 4,294,967,296 (4 gig in computer terms)... Sometimes the story ends with the king re-negotiating, sometimes the story ends with the king executing the mathematician to preserve his kingdom, and sometimes the king is astute enough not to take the deal. A monomial with power three is one that "cubes" the value of x. This is because we use the operation x*x*x to measure the volume that a given area of x*x takes up. If you have a cube that is 1 unit on each side and cut each side in half you will find that you have created 8 cubes. If the mathematician had asked to have the single grain of wheat cubed than the servants would have delivered 1, 8, 512, formula_16, formula_17 grains of wheat and the kings deal would have needed to be re-negotiated two days earlier. Polynomials. A polynomial of one variable, x, is an algebraic expression that is a sum of one or more monomials. The degree of the polynomial is the highest degree of the monomials in the sum. An polynomial formula_18 can generically be expressed in the form formula_19 or formula_20 The constants ai are called the coefficients of the polynomial. Each of the individual monomials in the above sum, whose coefficient ai ≠ 0, is called a term of the polynomial. When i = 0, xi = 1 and the corresponding term simply equals the constant ai. Also when i = 1, the corresponding term equals ai x. A polynomial having two terms is called a binomial. A polynomial having three terms is called a trinomial. Polynomial Equations. We refer to all functions with one independent variable as formula_18. Each instance of formula_18 can be represented by an equation (either a monomial or a polynomial) which may have one or more places where the dependent variable is equal to zero. These places are called roots and they represent the number(s) whose value(s) for x make the function formula_23 true. These roots are called the zeroes of the polynomial (singular is zero). A polynomial of degree 1, will always look like a line when you graph it, and always has 1 real zero. A polynomial of degree 2, a quadratic function, can have 0, 1, or 2 real zeroes. A polynomial of degree 3 (a cubic function) can have 1 or 3 real zeroes. A polynomial of degree 4 can have 0, 2, or 4 real zeroes. Complex (unreal) zeroes, when present, always come in pairs. In general, a polynomial of degree n, where n is odd, can have from 1 to n real zeroes. A polynomial of degree n, where n is even, can have from 0 to n real zeroes. When we graph polynomials each zero is a place where the polynomial crosses the x axis. A polynomial of degree one can be generically written as formula_24 where M and C can be any real number. We will see that quadratic functions are curves. The curve can bend before it ever touches the X axis in which case it has no zeroes, It can bend just as it touches the X axis, in which case it can have just one zero, or it can open up above or below the X axis in which case it will have two zeroes. If you think about this you will see that polynomials with an odd degree (1,3,5, ...) have to be positive and negative, so they have to cross the X axis at least once. Polynomials with an even degree (2,4,6...) might always be positive or negative and never have a zero. Normally we represent a function in the form formula_25, but when we are looking for the roots of the function we want y to be equal to zero so we solve for the equation of formula_26 where formula_27 Solving Polynomial Equations. Some polynomial equations can be solved by factoring, and all equations of degrees 1-4 can be solved completely by formulae. Above degree 4, there are no formulae for solving completely, and you must rely on numerical analysis or factoring. This means that for polynomials of degree greater than 4 it is often impossible to find exact solutions. Rational roots of polynomial equations. Often we are interested in the rational roots of polynomials. A root is much like a factor of a number. For instance all even numbers have a factor of two. This means you can write the even numbers as two times another number. That is the numbers 2, 4, 6, 8 ... can be written as 2*1, 2*2, 2*3, 2*4 ... . This fact is helpful when you have a fraction of two even numbers. Given a fraction of two even numbers called N and M formula_28 you could reduce the fraction by re-writing it as formula_29. By keeping fractions in lowest terms it's easier to know when you can add or subtract them without looking for a common denominator. An example of a use of a polynomial equation. There is a story that in grade school the mathematician Gauss was asked to add the numbers 1 to 100 sequentially. He is said to have intuited the sum could be expressed with the formula n(n+1)/2 and quickly gave the answer 5050. The basis of this formula is that the numbers 1 through 49 added to the numbers 99 through 51 each yield 100. It is interesting to look at how this formula works for the values 9 and 10. For 10 we add the numbers 1+9, 2+ 8, 3+ 7, 4+ 6 to get 40 and we add the two remaining terms 5 and 10 to get 55. For 9 we add the terms 1 + 8, 2 + 7, 3 + 6, 4+ 5 to get 4*9 = 36 + 9 = 45. In the first case the n + 1 is the odd number and represents adding the 10 and the middle number, the 5. In the second case the n is the odd number and the n+1 represents the sum for the preceding terms in the formula. You may or may not find stories like this intriguing based on how your personality reacts to what is known as the foundational crisis of mathematics. Learning mathematics is a lot like learning a foreign language. Some people seem more adept at learning languages than others, but with hard work learning a new language is something we can all do. Multiplying polynomials together. When we multiply polynomials together we rely heavily on the distributive property. For instance when we multiply 67 by 5 we can divide the equation into (60 + 7)*5 = (300 + 35) = 335. Additionally we can apply the commutative property to multiply multidigit numbers. 67*25 = (60 + 7)(20 + 5) = ((60 + 7)*20) + ((60 + 7) *5) = (60*20) + (7*20) + (60*5) + (7*5) = 1200 + 140 + 300 + 35 = 1675. These properties are the foundation for the different forms of the mechanical calculating tool the abacus. When multiplying polynomials together we do similar operations. We use the commutative property to divide the multiplier into its component parts and multiply the multiplicant by each of these parts. For instance to multiply formula_30 by formula_31 we first write the multiplicand and multiplier in terms of powers of x. This gives us formula_32 and formula_33 The terms raised to the zero power represent constant integer terms in our equations. Next we apply the commutative property to rewrite the equations as formula_34. We simplify these equations to be formula_35 (notice how our integer term drops out). Finally we combine like terms to get the answer x^3 + 2x^2 + x +0x^0. Let's repeat that in the more familiar columnar format of multiplication: 1x^2 + 1x^1 + 0x^0 * 1x^1 + 1x^0 1x^2 + 1x^1 + 0x^0 + 1x^3 + 1x^2 + 0x^1 = 1x^3 + 2x^2 + 1x^1 + 0x^0 = x^3 + 2x^2 + x By breaking a polynomial into its terms If we have a polynomial P(x) formula_19 The only possible rational roots (roots of the form p/q) are in the form formula_37 (Also know as the rational root theorem, or RRT) Binomials. binomial is a sum or difference of two monomials. These can also be called polynomials, but to specify, these are binomials. Examples. 2x + 2 2y - 7 How to factor. To factor binomials, find the greatest common factor between the terms and factor. Example. 4x + 2 The greatest common factor between these terms is 2 because both of the terms can be divided by it and the coefficient and constant is still an integer. The example factored would become: 2(2x+1)

How To Search/Yahoo. Yahoo! Search Search Fields. Yahoo! refers to the following as "Search Meta Words." Search Shortcuts. Yahoo refers to the following as Yahoo! Shortcuts. Some have yet to be listed in this wikibook. When typing a shortcut it looks just like a normal word search. The difference shows up when the search results appear. Below advertisements and above the numbered search results there will be an entry with a red Yahoo Y next to it. This shortcut entry may provide an answer, if using the calculator or dictionary, or it may link to further pages with the answer.<br><br> Other Features. Yahoo! Search also allows a number of searches which can only be done using templates on their web pages. These can be found in the advanced search. These include file format (doc, html, pdf, ppt, rss, txt, xls), search language, safesearch filter, and country. Other features not directly impacting search results include number of results listed per page.

Ancient Greek/Preface. At one time, all well-educated men (and they were almost always men) were expected to have at least a passing familiarity with Classical Greek. That age has passed, for better or worse, but many of the reasons that motivated the study of Greek are still forceful. Indeed, some of them are so common now as to seem trite and obvious: The people who used this language were the founders of Western civilization. They created bodies of thought that have profoundly affected the course of both intellectual and political history and are still influential to this day. They created and defined many of the forms that art continues to take. They laid the foundation for geometry, and invented the scientific method. To fully understand almost any area of human endeavour requires wrestling with the ancient Greeks. Now one can do this by reading translations. Certainly innumerable Greek texts, including all the "important" ones, have been translated into all the major languages. But we hardly need to review the problems of translation here. It is a second-best alternative at any time, and in the case of a language two thousand years old that arose in a culture very different from our own, it sometimes seems an astonishing feat that we manage to render anything at all. It is perhaps only due to the inestimable influence of the Greeks' language and thought on our own that we manage it so well. But by virtue of the fact that you are reading this, it's clear that you're considering an attempt at overcoming these obstacles by going directly through them, by studying Classical Greek. You may be wondering, though, is it for you? Of course, there's no single answer to this question. If Greek is not your first foreign language, it should not present any shockingly new difficulties. It is a bit more complex in some ways than, say, Spanish or German - for example, it has nearly twenty forms of the definite article - but the principles are the same. There are verbs that must be conjugated, nouns that must be declined, and so on. The tremendous practice you gained in learning your other foreign language(s) will serve you very well in learning Greek. And as a bonus, you'll never have to worry about learning to understand native speakers: There are none! If Greek will be your first foreign language, there are again advantages and disadvantages. Certainly the first few lessons may not be as easy as they would if you were learning, say, Spanish. And you're unlikely to find many other speakers among your friends, as you might with a modern language. But English has derived many words from Greek, and few of the principles of grammar are wildly different. Besides, if you don't know anyone else who reads Greek, you'll look all the more impressive by knowing how! Before you begin, a word on prerequisites. This course assumes no previous foreign language knowledge. As mentioned above, learning a third or fourth language is usually easier than learning a second, but all this course presumes is English fluency. We will try to avoid rote memorization where possible, but the fact is that memorization is impossible to avoid completely. Rules of grammar, of accent, even the alphabet itself must simply be memorized. This is not as difficult as many people seem to think, however, and the text will try to provide helps where possible.

Calculus/Systems of ordinary differential equations. We have already examined cases where we have a single differential equation and found several methods to aid us in finding solutions to these equations. But what happens if we have two or more differential equations that depend on each other? For example, consider the case where and Such a set of differential equations is said to be "coupled". Systems of ordinary differential equations such as these are what we will look into in this section. First order systems. A general system of differential equations can be written in the form Instead of writing the set of equations in a vector, we can write out each equation explicitly, in the form: If we have the system at the very beginning, we can write it as: where and or write each equation out as shown above. Why are these forms important? Often, this arises as a single, higher order differential equation that is changed into a simpler form in a system. For example, with the same example, we can write this as a higher order differential equation by simple substitution. then Notice now that the vector form of the system is dependent on "t" since the first component is dependent on "t". However, if instead we had notice the vector field is no longer dependent on "t". We call such systems "autonomous". They appear in the form We can convert between an autonomous system and a non-autonomous one by simply making a substitution that involves "t", such as y=(x, t), to get a system: In vector form, we may be able to separate F in a linear fashion to get something that looks like: where "A"("t") is a matrix and b is a vector. The matrix could contain functions or constants, clearly, depending on whether the matrix depends on "t" or not.

How To Search/Types. There is great variety within the set of searches that authors may include in this book. While the difference between the searches is self evident to some, it is not to others. For this reason, the types of searches are explained below. Types Explained. Internet search engine. An Internet search engine is a program designed to help you access files stored on a public server on the Internet. The search engine allows you to ask for media content meeting specific criteria (typically those which contain a given word or phrase) and retrieve a list of files that match those criteria. Data collection is automated and done by software often known as a Web crawler. Web search engines work by storing information about a large number of web pages, which they retrieve from the WWW itself. These pages are retrieved by a web crawler -- an automated web browser which follows every link it sees. The contents of each page are then analyzed to determine how it should be indexed (for example, words are extracted from the titles, headings, or special fields called meta tags). Data about web pages is stored in an index database for use in later queries. Some search engines, such as Google, store all or part of the source page (referred to as a cache) as well as information about the web pages. When a user comes to the search engine and makes a query, typically by giving key words, the engine looks up the index and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text. The usefulness of a search engine depends on the relevance of the results it gives back. While there may be millions of Web pages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to rank the results to provide the "best" results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another. The methods also change over time as Internet usage changes and new techniques evolve. Most Web search engines are commercial ventures supported by advertising revenue and, as a result, some employ the controversial practice of allowing advertisers to pay money to have their listings ranked higher in search results. Indexing/abstracting journal database. Indexing and abstracting databases developed as an electronic alternative to paper periodical indexes. Historically libraries provided catalogs to help find journals, magazines, and newspapers by title but they rarely catalogued the articles in each issue. Indexing and abstracting books and databases fill in this gap. One can search electronic indexes by at least article author, article title, and article subject. Most indexes have many more ways to access articles. Indexing and abstracting databases always contain indexed article information, sometimes contain abstracts, and rarely contain the full text of articles. In the age of the Internet and Google, using a database that doesn't have full text may seem antiquated but much of scholarly research still relies on such databases. The addition of article subject headings in indexes is done by humans (as opposed to automated computer programs) and from this addition come positive and negative affects. Adding subject headings requires trained people and such people have to be payed therefore, driving the cost of the index higher. On the other hand, being able to find similar articles by subject can save a great amount of time. Citation index. A citation index keeps track of which articles in scientific journals cite which other articles. This allows one person who wrote an article to find out how many people have cited their article. Library Catalog. "A library catalog is a register of all bibliographic items found in a library." A bibliographic item can be a book, video, portrait or about anything else that is considered library material. References. Much of the search engine section was originally copied from the search engine article from Wikipedia. The first sentence of the library catalog section was quoted from the library catalog article in Wikipedia.

Digital Photography. This guide assumes that you know how to use your camera in automatic mode and that you have your manual handy so you can work out how to do the things described here using your camera. Contributors. __NOEDITSECTION__

Guitar/Alternate Picking. Alternate picking is an important skill, because it allows you to play more than twice as fast than with just down picking. The basic idea is that if you are picking just on down strokes, every time you bring the pick back up to stroke down again, you are missing an opportunity to hit the string again. Essentially alternate picking is more efficient, because you have to move you hand less distance to hit the next note, and it can be an important difference between hitting the note on time or struggling to reach it. As with other guitar skills, it doesn't sound even a little difficult until you actually try and do it. It will take some time to master it and get really fast. After doing it for a long time, you will begin to notice that you are subconsciously deciding whether to alternate pick or not, depending on the underlying rhythm. Ultimately alternate picking allows you to play more efficiently, and thus faster. Hold the pick in whichever method feels best for you. Only the top of your pick should be seen and touch the string, because when you pick you cover less distance and use less energy. Your movement should only come from your wrist, not from your whole arm, and it should be precise. There are many ways to practice alternate picking, but really it is something that you have to merge into all of your guitar playing. Being able to alternate pick at the right time is a very important step, and it is one of the barriers that separate good guitar players and people who just play guitar. Lesson 1. To introduce yourself to alternate picking, start with a simple exercise beginning on the low E string. Play this pattern up and down the strings, and then up and down the whole neck. When you hit each note, you should make sure that you are always picking in the opposite direction of the previous note. Try playing faster, but always make sure you are fretting and picking each note clean to develop good habits. A metronome is a good item to help you with these sorts of exercises, because it helps you keep a steady pace. Always spend time practicing at your maximum speed, but not for the whole time; playing at an even pace is more important and builds your internal sense of rhythm. Once you are comfortable alternate picking, try fingering some chords and pick through them, using alternate picking where appropriate. You can stumble onto some famous songs completely by accident like this. Lesson 2. This pattern is a little more complicated, as it is a walk, where you play a repeating pattern that always starts on the next highest note. Continue the pattern up the strings, and make sure you are always alternate picking. You will start to notice when sometimes it is better to pick up or down twice in order to make the picking more efficient overall. Lesson 3. This riff combines palm muting and alternate picking. The open notes should be muted, and you should be using alternate picking. This riff is very similar to a riff from Metallica's One. Additional Lessons. If you want more exercises, please see other sections of this book, and perform the exercises there, except add in the alternate picking. Alternatively, you could take a song you already know, and then pick the chords using alternate picking. You will soon see how you can apply alternate picking into every part of your guitar playing.

Swing Dancing. This book is intended to serve as a guide to various forms of swing dancing, and will ideally contain descriptions and pictures of various moves. This textbook is of course not meant to be a replacement for actual practice and lessons, but a reference and source of new ideas. External Links. __NOEDITSECTION__

East Asian Calligraphy/Introduction. What is "East Asian Orthography"? Isn't it just those symbols you see in Chinatown or Koreatown, or in anime or manga? Really, East Asian writing is a lot more complex than that, and it is important to know what you're dealing with before you learn how to write an East Asian language. By East Asian writing, we are really talking about the set of writing used by the Chinese, Japanese, and Korean languages. But these languages use very different writing systems. Chinese, for example, uses Chinese characters or logographs, where each symbol represents a word or a word root (called "morphemes"), with one (or several) defined meanings and pronunciations. If English were written this way, for example, we would have individual symbols for simple words like "the", "at", "sun", "moon", etc. and a series of symbols for more complex words like "understand" and "approve", with one symbol for each part of the word. (For example, "understand" may be composed of two symbols, one for "under" and one for "stand".) Contrary to popular belief, Chinese characters do not in any way represent "ideas" or "philosophies" directly. It represents a language, and nothing more. Japanese, on the other hand, uses the kana system, composed of two syllabaries, hiragana and katakana. "Syllabaries" are systems where one symbol represents a syllable. For example, "ka" is a syllable, and hence in Japanese it is written with a single hiragana letter or a single katakana letter. Same with, say, "ki", which is written with another hiragana letter or a katakana letter. Hiragana developed out of stylized cursive Chinese characters, and katakana developed out of parts taken from Chinese characters. Chinese characters, known in Japanese as kanji, are also used in the Japanese language to write both Chinese loanwords and native Japanese words. Korean uses hangul, which is an alphabet just like the English one, with one letter for each discrete sound. Although Korean letters were originally invented as abstract, geometrical shapes, their stroke forms are nevertheless usually written just like those used in Chinese characters. In addition, Korean letters are arranged into square blocks by syllable, again, making Korean writing look similar to Chinese. Chinese characters, known in Korean as hanja, are also used to an extent in South Korea. In North Korea, hanja have been completely abolished. Hence, East Asian orthography is really a set of three very different writing systems: Chinese characters, with one symbol for each word root; Japanese kana, with one symbol for each syllable; and Korean hangul, with one symbol for each discrete sound. Despite their functional differences, however, East Asian writing systems stem from a common ancient Chinese root. By and large, they are written with the same strokes, use the same stroke order, and achieve the same general aesthetic effect. Moreover, Chinese characters are widely used in all three languages, and a thorough study of any one of the three languages would certainly entail a thorough study of Chinese characters. This textbook will, therefore, attempt to cover topics of East Asian orthography that are common to all three systems, namely, the aesthetic aspects of East Asian writing. With these aesthetic considerations in mind, it will be possible for you avoid common pitfalls of beginners, whose writing (be it in Chinese characters, Japanese kana, or Korean hangul) often end up looking misshapen and askew. On the other hand, this course will not focus on the functional aspects of the three different systems, which are, of course, all very different. That is the job of the individual language textbooks.

East Asian Calligraphy/History. The Chinese writing system can be traced back to the oracle bones of more than 4000 years ago, found in the ruins of the Shang dynasty, the first literate dynasty of China. The writing found on the oracle bones, known collectively as the Oracle Script, were mostly for divination purposes. Later on during the next dynasty (the Zhou), more types of writing appeared: on bronzeware vessels, on silk, on bamboo scrolls. It was in the early Chinese writing system of this period that great philosophers such as Confucius, Mencius, and Lao-tze recorded their thoughts and beliefs. In 221 BC, the Qin state of northwestern China brought the country under a unified bureaucratic empire, for the first time in Chinese history. The Qin set out to unify Chinese culture as well; they standardized and simplified the Chinese system into a common script, known today as the Seal Script, due to the primary use of their script today: on seals. The Qin Dynasty was short and lasted only 15 years. They were replaced by the Han Dynasty, who pushed China into a golden age just as Rome on the other side of the world heralded the golden age of Mediterranean Antiquity. The Han Dynasty would forever lend their name to the Chinese people; even today ethnic Chinese around the world call themselves Han and their writing system Hanzi (which passed into Japanese as Kanji and Korean as Hanja). In addition, the Han Dynasty saw the further development of the Chinese script into the Clerk Script. This script is used today primarily for stylistic purposes. As the Han Dynasty ended and China spun into several centuries of chaos and disunity, new writing styles emerged, including the super-cursive Grass Script, the moderately-cursive Running Script, and the neat, squarish Regular Script. The Regular Script is now the standard writing script of Chinese. It was also during this period that Chinese writing passed to Japan. The Grass Script and the Regular Script became, respectively, the foundations for Japanese hiragana and katakana. The next major development came in Korea, where in 1446, the "Hunmin Jeongeum" was published under the reign of King Sejong. In this document, a newly invented alphabet for Korean, Hangul, was presented. Hangul is the only major alphabet in the world designed explicitly with phonological principles in mind, that having been studied for centuries by scholars of Sanskrit and Classical Chinese. Originally Hangul was intended to be supplementary to Hanja; but the 19th and 20th centuries saw its rise to become the dominant script of the Korean language. The 20th century saw another important development: the simplification of Chinese characters. After taking over mainland China in 1949, the Chinese communists sought to eradicate illiteracy, especially in the countryside. To do this, they undertook a campaign to simplify the shapes of a large number of Chinese characters. The reformed characters, known as Simplified Chinese, have been universally adopted by both mainland China and Singapore. On the other hand, there are plenty of people as well who believe that the reform has bastardized the Chinese writing system and does little to combat illiteracy. The traditional characters, known as Traditional Chinese, are still in use in Hong Kong, Taiwan, and Macau, as well as many Chinese communities around the world.

East Asian Calligraphy/The dot. The dot stroke is the simplest stroke in East Asian writing systems. Despite its name, it is "not" just a dot — it has length (sometimes quite long), and direction. In fact, it is the shape of this stroke, and not its length, that makes it a dot stroke. Examples of the dot stroke: <br> If dot strokes can come in so many shapes or sizes, then what makes a "dot"? In general, a dot stroke is defined by the following properties: Let's take a look at three examples, the Chinese character for "heart", the Japanese katakana "mi", and the Korean syllable for "si": The first, third and fourth strokes of "heart", all of the strokes of "mi", and the second stroke of "si" all show the properties of dot strokes.

Amateur Radio Manual. The purpose of this book is to provide a manual appropriate for a North American Amateur Radio Licensing course with added information so that beginning amateurs will have a good reference source to continue their hobby. One of the goals is to make this a practical rather than a theoretical manual and to keep the language simple and understandable. Further reading. __NOEDITSECTION__

Swedish/Introduction. Welcome to the course. Welcome to a course in Swedish. When you have completed this course, you should have enough knowledge to speak, read and write the language rather well. In order to learn a language properly, you must take action, you must "do" something. So I suggest, after you've learnt the basics, that you look up some simple, easy Swedish literature, and start reading. Knowing what is easy is not easy if you don't know any Swedish at all though. If you know somebody who is Swedish, they might be able to help you to some nice reading. I will also try to put up some links to nice, easy articles here later. General remarks about Swedish. While Swedish is, like most European languages, not very closely related in how it is written and how it is pronounced, it is more so than English or French. Swedish, like English, also counts a fair number of dialects, including the southern "scanian" (which resembles Danish), "finlandssvenska" (the Finnish-Swedish dialect of Swedish-speaking Finns, mostly spoken in northern Finland), and several dialects different enough to be considered separate languages, although not recognized as such legally or in administration. There are nine vowels in Swedish: and 19 consonants: The consonants c, q, w, x and z appear mostly in words of foreign origin. à, é and ü are considered variants of a, e and y respectively. The combination kk is always written as ck in Swedish words. Syllable division. Syllable division marks the natural break in a word. When you know where the syllables divide, you can divide a word into its natural sections. This makes speaking correctly easier. You also get a correct speech rhythm. The general rule for syllable division is that each syllable contains one vowel each. Information about the language. First of all - Swedish is a North Germanic language, which is a subgroup of the Germanic Languages, containing languages as: Norwegian, Danish, Icelandic and Faroese, as well as Norn, which is extinct. Swedish is considered mutually intelligible to a great extent with Norwegian and to some extent with Danish - and native speakers of these languages often intercommunicate. Also since Swedish is a Germanic Language speakers of Western Germanic Languages - e.g. English and German - shouldn't find Swedish that hard to learn, since these languages share some common traits. Swedish is also one of the official languages of Finland. Alphabet. The Swedish alphabet is almost the same as in English, except for three additional letters, å/Å, ä/Ä and ö/Ö. These have no special function in sentences/words, they are normal letters, and you will see them in use nearly as much as any other letters would be in use in English. Here's how to say the alphabet letter by letter: The pitfalls. A few general things to be aware of, as most beginners find them hard, Sje- and tje-. Two quite similar consonant sounds frequently baffle beginners in Swedish. They are the "sje-" and "tje-" sounds. To someone who knows English, they are the sounds present in shear" and chain", respectively. The hard part is their spelling, which varies a lot. Speaking at the tip of your tongue. Swedish does very rarely involve making sounds at the back of your mouth. Vowels should be formed "near your front teeth". "L" and "T" are not thick as in English, and "R" always rolls. Noun gender. Even native Swedes cannot explain noun gender - there isn't any. Yet, it must be followed. The simple answer is you have to learn it for each noun. Getting Started. Okay, if you're ready, all you have to do is proceed to Lesson 1!

Spanish/Personal pronouns. Spanish has six different type of pronouns, the 1./2./3. person singular and the 1./2./3. person plural: Exercise: Personal Pronouns Back to lesson 1

Spanish/Gender of nouns. In English, the verb in a sentence changes depending on whether a noun is singular or plural. For example, in Standard English, it would be grammatically wrong to write "We is here", since "we" is plural but "is" is the singular form of the verb. We need to keep track of which words are singular and which are plural, but since we learn a noun's number when we learn the word, it isn't too difficult. In Spanish, we also need to keep track of another attribute, called the gender. Spanish has two grammatical genders, which are known as "masculine" and "feminine". Just as a word can be singular or plural, it can also be masculine or feminine. Sometimes it is obvious which gender a word is, such as the words for "man" and "woman". Other times, it may seem arbitrary. Just learn the gender of each noun you learn, and you won't have too much trouble. Gender of sexed nouns. Normally, for nouns that express gendered entities (people or animals), there is both a masculine-gender form and a feminine-gender form (example: el profesor (m), la profesora (f)). Normally, the feminine-gender words end with the letter 'a' and the masculine words end with the letter 'o'. If a masculine word ends with a consonant, the feminine adds 'a'. If word ends in 'a' it can be both masculine and feminine "(el artista, la artista)." Examples: Sex is not correctly expressed by the gender alone. If you want to say "I need a female student" you can say Necesito una estudiante. However, since gender is required but doesn't convey additional meaning, the sentence would be better understood if you say Necesito una estudiante mujer. In the plural, the masculine-gender form indicates there is at least one male, or that sex is unknown. Los niños is "the children". To indicate boys you must say los niños varones or los niños hombres "(the male children)". See also Formation of the feminine Gender of non-sexed nouns. Many words in Spanish have a fixed arbitrary gender, which is also called grammatical gender. This is true for all things: el pan "(bread)", la leche "(milk)." Most animals follow this rule: el camello "(camel)," la jirafa "(giraffe)." There are a few words applied to persons that have grammatical gender: el personaje "(personage, character)", la visita "(visitor)". Normally, the feminine-gender words finalize with the letter 'a' and the masculine-gender words end with the letter 'o'. Examples: Masculine-gender words ending in o: Feminine-gender words ending in a: Here the endings that are typical for feminine nouns. A mnemonic rule for most feminine-gender endings is the "word" "D-ión-Z-A." There is also a (much less strict) rule for typical masculine-gender endings. The endings can be summarized easily by the word "L-O-N-E-R-S": </table> Since there are many exceptions to some of the rules it is always good to learn the gender along with the noun. Definite articles normally help us to do this. Some of these exceptions can be memorized in groups. For example, although most nouns that end in "-a" are feminine and therefore take the "la" article, many nouns that end in "-ma" are exceptions to the rule and are masculine. This is because these words have a Greek origin. For example, "el tema, el programa, el fantasma, el clima" and "el diploma." However, many words ending in "-ma" have a feminine gender: "la cama, la broma, la norma, la rama, la fama, la yema, la estima, la espuma."

Dutch/Lesson 1A. Gesprek 1A-1. Let's have a look at some more conversations with everyday phrases. Some words will already look familiar. If not hover to see an instant translation. Try to memorize some phrases, particularly the greetings. Use the vocabulary box on the right to practice the individual words until you know them. Fill in the blank- 1A-1-F. First say the word you think should be in the blank, then use the hover method to check whether you were right. Pronunciation drill 1A-1-P. Listen to the following audio files and repeat what the speaker says in the pauses. Gesprek 1A-2. Jan en Mieke have a bite to eat in a small restaurant Saying thank you and please. We saw that Dutch makes a distinction between jij/je and u and that this has to do with formality and politeness. The same applies to the formulas used to say thank you and please. Please is "alsjeblieft" or "alstublieft". Both literally mean: "if it pleases you": "als het je/u belieft". It is used in a somewhat different way than in English as it can be used both to say "May I please have...": "mag ik alstublieft ... hebben", or for the answer "Here you are", "Here it is" as the waiter in the above dialogue. Alsjeblieft is commonly abbreviated to "ajb", whereas alstublieft is abbreviated to "a.u.b.". "Thank you" can either be "dank je" or "dank u". It is sometimes augmented with -wel: "dank je wel", "dank u wel". An even more informal way of thanking is to say "bedankt" "(you are) thanked". It is mostly used in the negative: "nee, bedankt" and can even sound a little abbrasive, as in "thanks, but no thanks". A formal alternative is "hartelijk dank" "Cordially (I say) thanks" The equivalent of "you are welcome" is "tot je dienst" or "tot uw dienst" "at your service". An alternative is "graag gedaan" "done with pleasure" or "niets te danken" "(there is) nothing to thank for". Expression like these are not used nearly much as their English counterpart, although this strongly depends on the region. Particularly in the northernmost provinces of the Netherlands (Groningen, Friesland e.g.) people tend to economize on politeness expressions, even find them annoying. Being direct is considered polite enough. Fill in the blank- 1A-2-F. First say the word you think should be in the blank, then use the hover method to check whether you were right. Quiz. <quiz display="simple"> -visit +pronunciation -friends ---+hoe +---jou -+--straat --+-spreekt ---+- y'all see them -+--- we see you +---- he sees me ----+ you see him --+-- you see her </quiz> Video. Review the personal pronouns and some other useful expressions in this YouTube video Quizlet. You can practice the vocabulary of this lesson at Quizlet (77 terms) Progress made. If you have studied the above well you should: Cumulative count: Les 1: 116 terms, Les 1A: 89 terms. Total 205 terms.

Canadian Constitutional Law. The following text is intended to provide an overview of the principles of Constitutional law of Canada and its related jurisprudence.

Computer Hardware. "NOTE:- This book is currently in the process of being merged. Some data could be out of place or already merged." Personal Computers (PCs) can be obtained in desktop, laptop, notebook and other portable formats. They are used in all areas of society. This module describes the parts of typical desktop personal computers. "please add your contributions" "Note: Should this stuff be moved to other pages?" Here is how : =Computer hardware= =Class 1 Components= Class 1 components are integral to the function of the computer. CPU. The CPU (Central Processing Unit) is the 'brain' of the computer. It's typically a square ceramic package plugged into the motherboard, with a large heat sink on top (and often a fan on top of that heat sink). All instructions to the computer are processed by the CPU. There are many "CPU architectures", each of which has its own characteristics and trade-offs. The dominant CPU architectures used in personal computing are and ARM. x86 is easily the most popular processor for this class of machine (the dominant manufacturers of x86 CPUs are and ). X64 is currently replacing X86 as it has superior performance. X86 is 32 bit, which means it has 6 0s and 1s to use at one instance while X64 can use 7 0s and 1s. Some programs are offered in 64-bit only. The other architectures are used, for instance, in workstations, servers or embedded systems. CPUs contain a small amount of static RAM (SRAM) called a cache. Some processors have two or three levels of cache, containing as much as several megabytes of memory. Dual Core Some of the new processors made by Intel and AMD are Dual core. The Intel designation for dual core are "Pentium D", "Core Duo" and "Core 2 Duo" while AMD has its "X2" series and "FX-6x". The core is where the data is processed and turned into commands directed at the rest of the computer. Having two cores increases the data flow into the processor and the command flow out of the processor potentially doubling the processing power, but the increased performance is only visible with multithreaded applications and heavy multitasking. Hyper Threading Hyper Threading is a technology that uses one core but adds a virtual processor to an additional thread at the same time. Normally the processor carries out one task and then proceeds onto the next task. But with Hyper Threading the processor continually switches in-between each task as if to do them at the same time. For more information, consult the Wikipedia article on . Case. Most modern computers have an "" case in which ATX-compatible power supplies, Mainboards and Drives can be mounted. During the 1980s and 1990s almost all cases were beige, even Apple's Macintosh line. A few rare exceptions to this were black. Only recently have computer case designers realized that there was a worthwhile market for other colors and designs. This has led to all sorts of modifications to the basic design of a computer case. Now it is easy to find cases with transparent windows and glowing lights illuminating their insides. Power Supply. All computers have some sort of power supply. This converts the supply voltage (AC 110 or 220 ) to different voltages such as 5 V, 12 V and 3.3 V. These are needed inside the computer system by nearly every component inside the computer. There will be a bunch of connectors coming off of the supply, called Molex connectors. They come in varying sizes, meant for different applications, such as the motherboard (usually the largest of the connectors), the hard and optical drives (a bunch of medium-sized connectors), as well as the floppy drive (a relatively small connector, also saw usage among videocards in 2004). As newer standards come out, the types of connectors have changed. Many power supplies now come with power connectors for Serial ATA hard drives. These are smaller and are "hot-swappable", meaning they can be removed and plugged in again without fear of data loss or electrical problems. Motherboard. The (also called ) is a large, thin, flat, rectangular fiberglass board (typically green in the past but are now typically black due to consumer demands) attached to the case. The Motherboard carries the CPU, the RAM, the chipset and the expansion slots (PCI, AGP - for graphics -, ISA, etc.). The Motherboard also holds things like the BIOS (Basic Input Output System) and the CMOS Battery (a coin cell that keeps an embbeded RAM in the motherboard -often NVRAM- powered to keep various settings in effect). Most modern motherboards have onboard sound and LAN controller, some of them even have on-board graphics. These are adequate for standard office work and system sounds. But dedicated sound and graphics cards plugged into the expansion slots offer much better quality and performance A motherboard includes many components such as CPU, RAM, FIRMWARE, INTERNAL AND EXTERNAL BUSES. RAM. is a memory that the microprocessor uses to store data during processing. This memory is volatile (loses its contents at power-down). When a software application is launched, the executable program is loaded from hard drive to the RAM. The microprocessor supplies address into the RAM to read instructions and data from it. RAM is needed because hard drives are too slow to operate with the speed of a microprocessor. Some of the types of RAM are SDRAM, SRAM, DDR RAM, Rambus RAM, SIMM, DIMM. PCI Express Cards/Slots. The PCI Express standard was created to replace both AGP and PCI slots, with PCI Express 16x and PCI 1x respectively for most implementations. The current implementation of PCI Express allows up to PCI Express 32x. The reason for the change is that the older PCI cards don't transfer data quickly enough to keep up with modern day gaming, Autocad and video editing software. Think of it this way, there is a tap that is two inches in diameter, but a drain that is only one inch in diameter. The water doesn't drain quickly enough and eventually the sink overflows. Just like a PCI video card. AGP Cards. Most graphic cards produced from about 1998-2004 were AGP (Accelerated Graphics Port) cards. They are placed in a certain slot on the mainboard with an extra high data transfer rate. The interface was invented to keep the graphics card away from the PCI bus, which was starting to become too constrained for modern graphics cards. Every graphic card carries a graphic chip (GPU) and very fast DDR RAM for textures and 3D data. Their data buses have 1X, 2X, 4X, and 8X speeds. The bus is 32-bit, much like PCI. AGP slots are slightly shorter than PCI slots and often brown in color. A similar type of slot called AGP Pro is longer and has extra power leads to accommodate modern video cards. It didn't really catch on in the mainstream market, and graphics card makers preferred to add an extra power connector to supply the power they needed. PCI Cards. The (Peripheral Component Interconnect) bus is the most popular internal interconnect for personal computers. They are usually white in color. The specification features: Common PCI implementations in desktop PCs feature: High-end implementations may also feature: There have been many revisions and evolutions of the PCI specification over the years. Recently, PCI-X has sought to extend the aging architecture for the needs of modern server-class machines, avoiding some of the performance bottlenecks of previous revisions. The new PCI Express specification seems likely to succeed PCI in all classes of personal computer within the next few years. ISA Cards. Industry Standard Architecture (ISA) cards were the original PC extension cards. Originally running on an 8-bit bus, they ran on a 16-bit bus as of 1984. Like PCI slots, they supported Plug-and-Play as of 1993 (prior to this, one had to set jumpers for IRQ interrupts and such). In comparison to PCI slots, they are rather long, and often black in color. They are not found on most computers built after 1999. Other removable media. Flash memory. Some common types of Flash memory cards are CompactFlash, Secure Digital (SD), and xD. There are other formats which are falling into disuse, such as Smartmedia (SM) and MultiMediaCard (MMC). Flash memory is faster than magnetic media and much more rugged. The main reason Flash hasn't yet replaced hard drives is that Flash memory is much more expensive per gigabyte than hard drives. USB Flash drive. Not everyone is familiar with exactly what a USB Flash Drive is, what it’s used for and why they are becoming increasing popular. So here’s a basic guide to what a USB Flash Drive is: USB Flash drives (also known as USB memory sticks, USB pen drives or USB thumb drives) were first commercially available in the year 2000. IBM launched them under the brand name “DiskOnKey” and they were introduced as a replacement for the floppy disc. By today’s standard the first USB flash drives had a tiny 8MB of storage capacity but even this was 4 times the amount of data that could be stored on a floppy disk. The portability of USB flash drives and the ability to carry your data around on a key ring or lanyard and simply plug it into a PC via a USB port meant they became very popular very quickly. Essentially a USB flash drive is a just a way of storing data and storing it on something that is lightweight, easy to carry, easy to use and works on all PC and Mac platforms. Over time larger storage capacities became available and the data transfer speeds increased to support the movement of larger amounts of information. Today typical USB flash drives are 2GB to 4GB but drives up to a whopping 64GB are now making their way into the market. A 64GB flash drive holds 8,000 times more data than the 8MB version first introduced in 2000!! Inside every USB flash drive is a small printed circuit board (controller chip) that is connected to a flash memory module (the piece on which the data is stored). These two elements are then encased in an outer shell that is typically made of plastic, metal or more recently wood/bamboo. The USB connector that protrudes out of the end of a flash drive is simply inserted into any PC or Mac and then the storage space on the USB flash drive is accessible and data can to saved to/from the drive. USB flash drives don’t need batteries because they draw all the power they need to work from the USB port they are plugged into. Today USB flash drives are very popular with companies because they can print their logo or brand onto the outside casing of the flash drive and give them away at trade shows, conferenceHealth Fitness Articles, exhibitions and so on. With the large amount of storage space now available on entry level versions of the flash drive companies are also pre-loading their sales brochures and other marketing material onto the memory of the flash drive – this not only saves them printing and transportation costs but it’s a really effective way of distributing large amounts of data and information about their company. People that are given branded flash drives (flash drives printed with a company logo on) are typically delighted to receive them because they have a high perceived value and because they can use they to save and transport their own data around. =Class 3 Components: Peripherals= Class 3 components are components which allow humans to interface with computers. Display device. Includes computer monitors and other display devices. and are common. LCDs are a more recent development, and are gradually replacing CRTs as they become more affordable. LCDs in addition to being lighter also use less energy and generate less heat. Sound Output. Includes internal or external speakers and headphones. Mouse. A user interface device that can enable different kinds of control than a keyboard, particularly in . It was developed at the Xerox PARC (Palo Alto Research Center) and adopted and made popular with the Mac. Today, nearly all modern operating systems can use a mouse. Most mice (sometimes the plural is 'mouses' to prevent confusion with the rodent) are made from plastic, and may use a ball to track movement, an light, or a . Today you can get a wireless mouse that allows you to easily give a presentation without being tied to a desk. These mouses are usually LED or Laser based tracking. History. In 1964, the first prototype computer mouse was made to use with a graphical user interface (GUI), "windows". received a for the wooden shell with two metal wheels (computer mouse U.S. Patent # 3,541,541) in 1970, describing it in the patent application as an "X-Y position indicator for a display system.". It was nicknamed the mouse because the tail came out the end, Engelbart revealed about his invention. His version of windows was not considered patentable (no software patents were issued at that time), but Douglas Engelbart has over 45 other patents to his name. There was also a DB-9 connector that was used to be an old serial mouse connector. Keyboard. A is an input device which is connected to a computer and used to type instructions or information into the computer. Typically, a keyboard has about 100 or so keys. Printer. A printer makes marks on paper. It can print images and text. The most common types of printers today are The average printer of the early 1990s would connect to a computer through its parallel port. To connect it to the computer via parallel port, one would have to screw it into the port. Today many printers are connected through USB. This is because it is easier to connect and remove through a simple plug and play system. It also allows for faster transfer speeds than parallel. Scanner. A scanner is a device for digitizing paper documents into images that may be manipulated by a computer. The two main classes of scanner are If the original document contained text, Optical Character Recognition (OCR) software may be used to reconstruct the text of the document from the scanned images. Modem. A contraction of "Modulator - demodulator", a modem allows a computer to communicate over an analogue medium (most commonly a telephone line). The modem encodes digital signals from the computer as analogue signals suitable for transmission (modulation) and decodes digital data from a modulated analogue signal (demodulation). Using modems two computers may communicate over a telephone line, with the data passed between them being represented as sound. Modems are usually involved with dial-up internet services. As broadband catches on, they are falling into disuse. However, the devices used to connect to broadband connections are also called modems, specifically DSL Modems or Cable Modems. CD-Roms. A CDROM (compact disk read-only memory), also written as CD-ROM, is a type of optical storage media that allows data to be written to it only once. This contrasts with memory, whose contents can be accessed (i.e., read and written to) at extremely high speeds but which are retained only temporarily (i.e., while in use or only as long as the power supply remains on). Although the disc media and the drives of the CD and CD-ROM are, in principle, the same, there is a difference in the way data storage is organized. Two new sectors were defined, Mode 1 for storing computer data and Mode 2 for compressed audio or video/graphic data. CD-ROM Mode 1. It is the mode used for CD-ROMs that carry data and applications only. In order to access the thousands of data files that may be present on this type of CD, precise addressing is necessary CD-ROM Mode 2. CD-ROM Mode 2 is used for compressed audio/video information and uses only two layers of error detection and correction, the same as the CD-DA. Therefore, all 2,336 bytes of data behind the sync and header bytes are for user data =Appendix A: Connectors and Cables= There are many different types of connectors and cables in personal computers, and this section will address as many as the various editors deem relevant. Internal Connectors. Several types of cables are used to connect components together inside the case, providing power and a path for data. These include: External Connectors. Without connections to the rest of the world, a computer would just be a fancy paperweight. Numerous connectors are used to make a computer useful. = Units of Information = In the world of computers, a unit of information is how much a certain data storing system can hold and is used to measure how much other systems can hold as well. There are two types of units that are the most typical which are bits, which exist is two states, or bytes, the equivalent of eight bits. Bits make up the foundation of unit information. Without bits there would be no bytes, nibbles, nor words.

How To Search/MOBIUS Consortium. MOBIUS Boolean Operators. See ../Millennium-III/ Other Operators. See ../Millennium-III/ Search Fields. See ../Millennium-III/

How To Search/Millennium-III. Millennium is an integrated library system written and maintained by the company Innovative Interfaces, Inc. It is the software that libraries buy and it is where they place their catalog records for library items. The operators and fields are similar across most Millenium installations.

Bicycles/Maintenance and Repair/Shifters/Rapidfire Shifter Lubrication. This is for the Shimano A20 "rapidfire" shifter switch (on the handlebars) but a similar situation may exist for other brands/models. The shifter consists of two levers and an enclosed ratchet mechanism with pawls. If pushing on the lever fails to move the idler wheels of the derailleur (on the chain), then a likely cause is lack of lubrication. If the old lubricant gets hard, the pawls will stick. So remove the switch and then remove a cover. Push-pull the pawl that's giving trouble with a small screwdriver and watch what happens. The pawls have tiny springs that push them into contact with a lugged wheel. If a pawl fails to maintain contact with the lugged (or notched) wheel, then, if the spring isn't broken, it can be fixed by lubing the pivot point of the pawl. Work the pawl back and forth with a small screwdriver, etc. right after applying a drop or two of lube oil. When the spring freely moves the pawl into contact with the lugged wheel, it's fixed.

Canadian Tort Law. This text is intended to provide an overview of the current law of torts, and its relevant jurisprudence and history.

Canadian Contract Law. The following text is intended to provide a survey of the law of contracts in Canada.

Canadian Constitutional Law/Charter of Rights and Freedoms. Introduction. Up until 1982, the previous section covered just about all of Canadian constitutional law. In just over two decades, the "Constitution Act, 1982" has had a predictably enormous impact on constitutional law. The most important section of the "Constitution Act, 1982", both for the legal community and for the general population, has been the Canadian Charter of Rights and Freedoms ("Charter"). The Supreme Court of Canada has spent most of the past twenty years interpreting the "Charter", and in so doing, has caused governments and lawyers to rewrite the basic rules of almost every area of public law. Before the "Charter" came into effect, Canadian law had a melange of legal human rights protections. For the average person, they worked very well, although what most people now consider enormous injustices were legally inflicted on some. The Supreme Court of Canada held that the Unwritten Constitution protected some human rights. In "Roncarelli" v. "Duplessis", [1959 121.], the Court ruled that the Constitution protected the people from arbitrary action by government officials. The federal government enacted the "Canadian Bill of Rights" in 1960, although it is now remembered mainly for the occasions that courts refused to apply it. In addition, some provinces had human rights legislation which forbade people from exercising their civil rights in discriminatory ways. However, as a general rule, no instrument permitted courts to strike down laws which violated human rights. This changed in 1982 by virtue of s. 52 of the "Constitution Act, 1982", which stated that any law that violated the Constitution, including the new part of the Constitution containing the "Charter", was of no force or effect. In order to give full effect to the "Charter", the Supreme Court of Canada decided to give the "Charter" a "broad and liberal interpretation." (R. v. Big M Drug Mart Ltd., [1985 1 S.C.R. 295]). The Court adopted a "purposive" approach, asking what the purpose of protecting the rights in question are, and giving effect to those purposes through the Court's interpretations of their meanings. This contrasts with the Supreme Court's interpretation of the "Canadian Bill of Rights", in which the meaning of the words of the Bill were interpreted so narrowly that the Bill protected virtually no rights in practice. Applicability of the Charter. According to s.32, the "Charter" applies to "the Parliament and government of Canada" and the "legislature and government of each province". It does not apply to private individuals or corporations. If Mr. Smith discriminates against Mr. Jones, Mr. Jones cannot go to court and sue Mr. Smith for violating his "Charter" rights (although Mr. Jones would probably be protected against discrimination by other legislation). Of course, the "legislature and government" is a broad term. How far does it apply? To organizations that receive government grants? To people who bring a private dispute to a court created by the government? In "RWDSU" v. "Dolphin Delivery", [1986 2 S.C.R. 573], the Supreme Court of Canada decided that the "Charter" did not apply to a dispute between two private parties before the courts. More controversially, it also decided that the "Charter" did not apply to the common law, unless the common law was the basis for government action. So, even if the common law restrictions against picketing violated the picketer's freedom of expression, the "Charter" would not protect him from being sued by the target of the picketing. The "effective control test" determines whether an organization is part of the government or not for the purposes of "Charter" s.32. In "Mckinney" v. "University of Guelph," [1990 3 S.C.R. 229], the Court decided that Universities are not part of the Government, even though they receive most of their money from the government. The main question to ask is how much control the government has over the institution: Is there a law that directs how the institution will operate? Does the government appoint the majority of the institution's board of directors? Does the institution have any history or guarantees of independent action from government? The greater the government control over the operation of the institution, the more likely it is to be a part of the government, although different Supreme Court decisions have required different amounts of control. Limits on Rights. The first section of the "Charter," somewhat surprisingly, is the main section placing limits on the rights and freedoms contained in the "Charter". Section 1 states: "The Canadian Charter of Rights and Freedoms guarantees the rights and freedoms set out in it subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society." For "Charter" rights to be limited, the limits must meet three requirements: The second and third requirements are relatively clear. "Prescribed by law" means that the limits must be written either in legislation or regulation. A governmental limit on "Charter" rights cannot be arbitrarily decided by an official. Nor can it be contained in rules which do not amount to "law", such as administrative manuals. "Demonstrably justified" means that the burden of proof is on the government to prove that the limits it has imposed are reasonable. In court, this means that once the plaintiff proves on a balance of probabilities that his or her rights have been violated, the government must prove on a balance of probabilities that it is reasonable. On the other hand, the question of what constitutes a "reasonable limit" in a "free and democratic society" is perhaps the most important question of modern constitutional law. Most major "Charter" cases in Canada do not turn on the question of whether a right has been violated (the courts often find that it has been), but whether the law constituted a reasonable limit on that right. The test for deciding whether the violation of a "Charter" right is a reasonable limit on a right or freedom was created by the Supreme Court in R. v. Oakes, [1986 1 S.C.R. 103]. Known simply as the Oakes test, it asks the following questions: The Oakes test is still used by the Supreme Court, although it has nuanced the second part of the proportionality test. The Supreme Court found that a limit on a right should infringe at right "as little as possible" when the objective of the law is to set relations between the government and the individual (for instance, in criminal law, where it is the government against the individual). However, the government should have more flexibility when trying to strike a balance between different groups of people. This latter case would come up most often in areas of social welfare. Where the government cannot afford to give everyone equal benefits, it will almost always have to create a somewhat arbitrary dividing line, such that some people have their right to be treated equally violated. The Court must give some flexibility to the government in deciding whom to give benefits and whom to deny. In such a case, the Supreme Court reasoned in "McKinney", the "minimal impairment test" is whether the government had a "reasonable basis" for believing that the right to equality has been violated as little as possible to achieve the government objective. Freedom of Expression. Perhaps other than the Equality provisions, freedom of expression ("Charter" s. 2(b)) has created the most important litigation and had the biggest impact on Canadian society. One of the most important questions to be litigated was what was protected as "expression". In Irwin Toy ltd. v. Quebec (Attorney general), <no wiki>[1989</no wiki> 1 S.C.R. 927], the Supreme Court ruled that anything that "conveyed meaning" was expression. This meant virtually any way that someone chose to express themselves, whether through words, acts, or depictions. Anything that conveyed meaning and was not in "an unacceptable form" (i.e., violence or threats of violence), was protected by the "Charter". The second question the Supreme Court answered in "Irwin Toy" was what constituted a violation of the right to free expression. If the purpose of the government restriction on expression was to restrict certain content, then that restriction violates the "Charter". This includes restricting certain methods of conveying meaning that are tied to the content itself (e.g., instead of banning rock music, the content, banning FM radio, the method of conveying the music). If the purpose of the limit is not to restrict content but to prevent certain harmful effects from the way the content is physically expressed, then the court must examine the effects of the restriction. If the restriction has the effect of frustrating "the pursuit of truth, participation in the community, or individual self-fulfillment and human flourishing", then the restriction violates the "Charter". The burden of proof is then on the government to show that the restriction is reasonable under the Oakes test. If it is not reasonable, then the restriction on expression is unconstitutional. In cases after Irwin Toy, the Supreme Court has found that political expression promotes "the pursuit of truth, participation in the community, or individual self-fulfillment and human flourishing" more than other types of expression, such as commercial advertising or pornography. Therefore, almost all restrictions on political expression have been found to be violations of the right to free expression. Another important finding in "Irwin Toy" was that corporation has the right to free expression (although much of its expression will be commercial advertising, the restriction of which is not always a violation of free expression). Search and Seizure. Section Eight of the Canadian Charter of Rights and Freedoms provides everyone in Canada with protection against unreasonable search and seizure. This Charter right provides Canadians with their primary source of constitutionally enforced privacy rights. Typically, this protects personal information that can be obtained through searching someone in pat-down, entering someone's property or surveillance. Under the heading of legal rights, section 8 states: Reasonable expectation of privacy. Generally speaking, this right does not protect against normal searches or seizures. Rather, the right focuses on the action being unreasonable on the basis that it violates an indivdual's reasonable expectation of privacy. Equality. According to s. 15 of the "Charter", everyone is equal before and under the law and has equal protection and equal benefit of the law, without discrimination. Section 15 further lists some prohibited grounds of discrimination: race, national or ethnic origin, colour, religion, sex, age, mental ability, and physical disability. Andrews v. Law Society of British Columbia, [1989 1 S.C.R. 143]defined discrimination. Discrimination is a distinction which imposes disadvantages or withholds advantages based on the characteristics of an individual or group. A mere distinction is not enough. It must be a distinction based on characteristics that a person has because he or she belongs to a certain group. That group must either be distinguished by one of the prohibited grounds above, or "analogous" grounds. A ground is analogous if it has some of the following similarities to the grounds listed, such as: "Andrews" decided that being a non-citizen was an analogous ground of discrimination. The Supreme Court has also ruled in Vriend v. Alberta, [1998 1 S.C.R. 493] that sexual orientation is an analogous ground. Vriend is also important as being the first case in which the Supreme Court required the provinces to add a new prohibited ground of discrimination in their human rights legislation. Provincial human rights legislation, unlike the "Charter", apply to private disputes. Exclusion of Evidence. Practices regarding what evidence may be brought against an individual in trials are addressed by section 24(2). This subsection is said to make Canadian practices regarding this matter more like those in the United States; however, the Canadian standards are still not as strict as the US standards. Whereas in the US, any evidence will not be used against the individual if it was acquired in an illegal way, for evidence to be excluded in Canadian trials, it must not only have been acquired illegally but must also threaten to bring the Canadian court system into "disrepute."[4] The 1987 case R. v. Collins attempted to define this. It was ruled that evidence should be excluded if it would render the trial unfair, and furthermore, the more Charter rights are violated, the more courts should have an obligation to exclude the evidence that violated the rights. Often, it is the right to have counsel and the security from unreasonable search and seizure that, when infringed, lead to evidence being excluded. "Notwithstanding" Clause. The addition of the "Charter" to the Constitution was a radical change in Canadian constitutional law. To assuage concerns that the courts were being given too much power to rewrite and reinterpret legislation, s.33 was included in the "Charter." Under this provision, legislation can be made immune from being challenged as a violation of certain Charter rights. These include freedom of expression, religion, assembly, association, and freedom from discrimination, as well as criminal rights. Legislation can operate "notwithstanding" these rights for renewable terms of five years. This clause has rarely been used in practice. External links. Return to Constitutional Law

PHP Programming/The do while Loop. The do while loop. The do while loop is similar in syntax and purpose to the . The do/while loop construct moves the test that continues the loop to the end of the code block. The code is executed at least once, and then the condition is tested. For example: <?php $c = 6; do { echo 'Hi'; } while ($c < 5); Even though $c is greater than 5, the script will echo "Hi" to the page one time. PHP's do/while loop is not commonly used. The continue statement. The continue statement causes the current iteration of the loop to end, and continues execution where the condition is checked - if this condition is true, it starts the loop again. For example, in the loop statement: <?php $number = 6; for ($i = 3; $i >= -3; $i--) { if ($i == 0) { continue; echo $number . " / " . $i . " = " . ($number/$i) . "<br />"; ?> the statement is not executed when the condition i = 0 is true.

How To Search/Directory of Open Access Journals. Directory of Open Access Journals (DOAJ) - Journal Search Other Features. The DOAJ searches, both journal and article level, seem to have primitive searching mechanisms at the moment. Using this site as a directory for finding open access journals seems to be its forte at this time. 07/29/04

How To Search/Library catalog. Library catalog searches are listed below.

Statistics/Summary/Quartiles. Quartiles. The quartiles of a data set are formed by the two boundaries on either side of the median, which divide the set into four equal sections. The lowest 25% of the data being found below the first quartile value, also called the lower quartile (Q1). The median, or second quartile divides the set into two equal sections. The lowest 75% of the data set should be found below the third quartile, also called the upper quartile (Q3). These three numbers are measures of the dispersion of the data, while the mean, median and mode are measures of central tendency. Examples. Given the set {1,3,5,8,9,12,24,25,28,30,41,50} we would find the first and third quartiles as follows: There are 12 elements in the set, so 12/4 gives us three elements in each quarter of the set. So the first or lowest quartile is: 5, the second quartile is the median 12, and the third or upper quartile is 28. However some people when faced with a set with an even number of elements (values) still want the true median (or middle value), with an equal number of data values on each side of the median (rather than 12 which has 5 values less than and 6 values greater than. This value is then the average of 12 and 24 resulting in 18 as the true median (which is closer to the mean of 19 2/3. The same process is then applied to the lower and upper quartiles, giving 6.5, 18, and 29. This is only an issue if the data contains an even number of elements with an even number of equally divided sections, or an odd number of elements with an odd number of equally divided sections. Inter-Quartile Range. The inter quartile range is a statistic which provides information about the spread of a data set, and is calculated by subtracting the first quartile from the third quartile), giving the range of the middle half of the data set, trimming off the lowest and highest quarters. Since the IQR is not affected at all by outliers in the data, it is a more robust measure of dispersion than the IQR = Q3 - Q1 Another useful quantile is the quintiles which subdivide the data into five equal sections. The advantage of quintiles is that there is a central one with boundaries on either side of the median which can serve as an average group. In a Normal distribution the boundaries of the quintiles have boundaries ±0.253*s and ±0.842*s on either side of the mean (or median),where s is the sample standard deviation. Note that in a Normal distribution the mean, median and mode coincide. Other frequently used quantiles are the deciles (10 equal sections) and the percentiles (100 equal sections)

Calculus/Summation notation. Summation notation allows an expression that contains a sum to be expressed in a simple, compact manner. The uppercase Greek letter sigma, Σ, is used to denote the sum of a set of numbers. Let formula_2 be a function and formula_3 are integers with formula_4 . Then We say formula_6 is the lower limit and formula_7 is the upper limit of the sum. We can replace the letter formula_8 with any other variable. For this reason formula_8 is referred to as a "dummy variable". So... Conventionally we use the letters formula_8 , formula_12 , formula_13 , formula_14 for dummy variables. Here, the "dummy variable" is formula_8 , the "lower limit" of summation is 1, and the "upper limit" is 5. Sometimes, you will see summation signs with no dummy variable specified, e.g., In such cases the correct dummy variable should be clear from the context. You may also see cases where the limits are unspecified. Here too, they must be deduced from the context. Common summations. formula_18 formula_19 formula_20 formula_21 formula_22

Introduction to Canadian Law. Legal Systems. Every country has its own legal system. Many countries follow in a common legal tradition with other countries. Some populations within a country may also have their own legal traditions separate from those of the country they inhabit. The Common law and the Civil law traditions are generally thought of as the two traditions that operate in Canada. However, many aboriginal law traditions exist in various forms, and religious legal traditions, such as Islamic and Jewish law, have a great influence on the lives of many Canadians. At the risk of over-generalization, the Common law is a system whereby judges have a large influence in making law, by referring to past judicial decisions where legislation does not provide an answer to the legal question at hand. By expanding upon and reinterpreting old decisions, judges develop the Common law, while at the same time consciously making only incremental reinterpretations, so that the law develops gradually. The Civil law is a system whereby the legislature adopts a Code which has many general legal principles. Judges refer to these general principles to solve specific legal problems; they need not refer back to how previous judges resolved similar specific issues, or even how they themselves resolved decided similar specific issues in the past. At the same time, judges have a high regard for experts in particular fields of law, whose publications are influential on judges. It is not uncommon for a Civil Code to last one or more centuries before a major reform. The Hierarchy of Authority/ Sources of Law. In Canada, this is the generally recognized hierarchy of authority: In the Quebec tradition, the hierarchy looks more like the following: Generally, a judge will give more weight to the top of the hierarchy. Useful Basic Concepts. Justice: Justice is a term in philosophy and law, but also in the popular imagination. People bring cases to court or write letters to their government because they wish for a just result. Justice is often seen as a moral concept which is broader than law as defined by courts and the government. Law: This concept has many different meanings. The average person thinks of law as "legislation", i.e., the written document approved by a legislature describing what may or may not be done legally. However, lawyers tend to use the word "law" in a broader context: the ensemble of the constitution, legislation, regulations, judicial decisions, agreements, and any number of other types of enforced rules that have an official status. Some people also extend the meaning of "law" to cover everyday rules that people create as they interact. For example, many legal anthropologists study law in this way. Statute: This is what most people call a "law": a written document, passed according to the rules of a legislature, which the government is to enforce. Also called an Enactment, an Act, legislation. It usually deals with a specific topic, which will be used in identifying and distinguishing it from other statutes i.e. the Immigration Act or the Income Tax Act. Legal Theory. Positivism. This is really what you would think seeing that word. The idea is that the law is a "posited" thing. In other words: law is law because it has been made in a certain way. Nothing else is law. As long as people agree on the way law is made, it is easy to know what is law and what is not. This view of law is most famously explained in the work of H.L.A. Hart, who wrote "The Concept of Law". In it, Hart says that there are primary and secondary rules in a society. The primary rules tell us how new (secondary) rules can be made. For example, in Canada any new federal law has to be approved by the House of Commons. Any new rule that doesn't respect this "primary rule" cannot be a law because it wasn't passed the right way. Legal positivism says that only laws that are passed according to the primary rules count as real law. This leads to a very formal outlook on law that emphasizes correct structure. It is a powerful analytical tool because it allows us to focus on one kind of rule while excluding others which can be distracting. However, for the positivist, the content of a rule is less important. Morals or any of the other fuzzy stuff don't come into play. This idea of "positive law" has been criticized by scholars including Ronald Dworkin because it sometimes fails to deal effectively with morally complex issues. For example, imagine that a government passes a new law, in the correct form, and this law makes it illegal to feed your children. It sounds absurd, but a strict positivist will hold that this is valid law because it was passed in the right way. Critical Legal Studies. Critical Legal Studies (CLS) is a movement in legal theory which originated in the United States in the 1960s and 1970s. A group of legal scholars began to study law from a left critical perspective. Among them was Duncan Kennedy, a professor who wrote the short book "Legal education and the reproduction of hierarchy : a polemic against the system" . People are often encouraged to see law and the courts as neutral and fair institutions. As the title of Kennedy's work indicates, critical legal scholars contest this view of law. Their goal is to expose the biases and prejudices which underlie much legal reasoning. Instead of talking about neutral legal rules and technicalities, critical legal studies focuses on relationships of power. While a positivist asks "is this a real law?", the critical scholar asks, "who benefits from this law?" and "how much justice can you afford, if you can't pay a lawyer?" Critical legal studies remains a popular movement among law students and left practitioners. As its name implies, however, the movement focuses more on negative criticism of legal institutions than on building social change in a progressive way. For this reason, the movement has itself been criticized by some legal academics who accuse CLS scholars of "trashing" institutions without offering a constructive alternative. Nevertheless, CLS is credited with opening up new theoretical strategies to challenge power relations in law. Other movements in legal theory such as feminist and critical race approaches are said to have grown out of the CLS movement. Critical Race Theory. Critical race theory is a legal perspective which focuses on issues of race and ethnicity as reflected in law. This includes, but is not limited to, inquiry on systemic discrimination in legal institutions (courts, tribunals, bar associations). Issues like racial profiling, access to legal services and law school admissions of people of colour are other examples. Canada has fewer academic resources on critical race theory than the United States, but there are some works which are of note. Carol A. Aylward's book, "Canadian critical race theory : racism and the law" provides a clear introduction to the topic. Questions discussed include when to raise the question of racial discrimination in the courtroom and why Canada might lack the diverse critical race scholarship of the U.S. Another work of interest is Constance Backhouse's book, "Colour Coded: A Legal History of Racism in Canada 1900-1950". In it, Backhouse offers detailed, well-researched information on some little-known facts about race and law in Canada. These include the activities of the Ku Klux Klan in Ontario in the 1930's, the "White Women's Labour Law" which prevented Chinese business people from hiring caucasian women in the 1920's, the shooting of a all black school the "Jace Bueckert Acadmey" in 1919 and the banning of dancing and potlatch ceremonies by Aboriginal peoples in Canadian history.

PHP Programming/PHP Include Files. Includes. There are two methods of including a file in PHP: codice_1 and codice_2. include "file.php"; require "file.php"; They both perform essentially the same function, but have one major difference: codice_1 will only throw a warning if there is a problem during the include process; codice_2, however, will halt execution in this scenario. Therefore, a script's dependencies will often be called with codice_2. Prior to version 4.0.2, codice_2 also attempted to read a file, regardless of whether the code in that file was executed or not. This means that if a file did not exist, an error would be thrown even if it would never be interpreted. The following code: <?php if (false) { require "some_nonexistent_file.php"; require "another_nonexistent_file.php"; would therefore fail on the first codice_2 in versions before 4.0.2, and the second in all other versions. Include Once. Additionally, there exist many code libraries, class definitions, and variable declarations that you will want to separate into an include file, but that should only be called into the current script once. To ensure that these libraries are only included once, php includes the codice_8 and codice_9functions. Each time one of these functions is called, the php parser remembers which file it has called. If another codice_8or codice_11 attempts to load the same file, the parser will simply skip the command. It will produce no error or warning, it will simply act as though the command had executed successfully. This is because, in fact, it has. IMPORTANT: If you include a file once with codice_8 and then later using codice_13, the file will be included a second time. If a file is included using codice_8 and a call to the same file is made by codice_9, it will not be included again. Include_once() and require_once() have the same 'memory,' as it were.

Zope. Zope is an open source web server built on top of Python. It is most commonly used for the content management systems Plone and CPS and the enterprise resource planning system ERP5. This textbook will help you install and operate a Zope server. Installation. Zope Win32 binaries and source code can be downloaded at the Zope Website. Windows. From the above page, download the file Zope-x.x.x-x-win32-x86.exe, where "x.x.x-x" is the version of Zope you want, such as 2.7.2-0. When the file is finished downloading, execute it. An installer should begin running. A welcome screen should pop up. Click "Next", and after reading the Zope Public License, click "Next" again. This brings you to a prompt asking you for a Zope site name. You can select any alphanumeric name you wish, although "Zope" is a reasonable default. You will then be asked to confirm the installation directory (by default C:\Program Files\Zope), and select an administrator username and password. For security reasons, it is highly recommended that you change these from the initial settings, as the Zope administration interface can be accessed over the Internet! After clicking "Next" on this final screen, Zope will install itself into the specified directory and ask whether you want it to run as a service or if you would like to start it manually. If the system is not Windows NT–based (this includes Windows 2000 and XP), the only choice will be to run it manually. Unix and Linux. Debian/Ubuntu using Debian packages. Get the zopex.x package, where "x.x" is the version of Zope. After downloading and installing, there is no instance of Zope running or runnable yet; the Debian package provides a tool for configuring instances, dzhandle, which can be run from the shell. dzhandle can be used to make and remove Zope instances and to configure existing instances. "To run it, you might need to be root." To create a new instance, this syntax is used: dzhandle -z <zope-version> make-instance -m <mode> -t <technique> -r <restartmode> -u <initialusername:password> [--service-user <system user> --service-port <port>] <instance name> For further information, consult the dzhandle manpage. This can be used to start an instance: dzhandle zopectl <instance name> start Building from source. After downloading the Zope source code, switch users to root using the su command. Change directories to the location in which you saved the archive, and untar the archive: $ tar zxf Zope-x.x.x-x.tgz where "x.x.x-x" is the version of Zope you downloaded, such as 2.7.2-0. Change into the directory created by the archive extraction (usually Zope-x.x.x-x) and run the ./configure script. Assuming that you have the Python interpreter, the installation will be configured and the script will then ask you to run make. Execute the command, and then make install. By default, the Zope binary directory will be /opt/Zope-x.x, and the Zope data directory will be /usr/local/zope. Getting Started. Zope initially runs on port 8080 (9673 on Debian systems due to a port conflict). Therefore, you can test your server by opening your favorite Web browser and typing "http://localhost:8080/" into its location box. A Zope introductory page should load. If you get a "connection refused" error, make sure that Zope is actually started (a simple Ctrl-Alt-Del on Windows or ps aux on Unix and Linux should be enough for you to determine whether or not it is running). The first thing you will want to do is log on to the Zope Management Interface, which is linked to near the bottom of the page. You will be asked for your administrative username and password, and then given access. Using Zope with Apache. There are two methods of forwarding Zope information through Apache: mod_proxy and mod_rewrite. Some more notes are here.

Bicycles/Maintenance and Repair/Brakes/Coaster Brakes. Coaster Brakes. Coaster brakes don't need adjusting but they may need lubricating to reduce wear. They are supposed to be greased with a special high viscosity lubricant such as Sachs: "fett fur stahlbremsmantel" which is likely no longer available. So instead use a cheap, high friction grease. To take the hub apart, Torpedo and Sturmey Archer say to start on the brake lever side, but I've seen the opposite proposed. However, you need to take apart the hub to apply grease so it's a lot easier to lubricate the brakes with heavy oil that doesn't contain anti-friction additives. Apply it via an oil filler hole in the hub (if it exists). Don't use oil with anti-friction additives such as teflon or graphite that will result in slippery brakes. On a long downgrade of over 1000 feet (300 M) the coaster brake may overheat and the any oil in it may boil and smoke. One may try filling the hub with water to keep the brakes cool by generating steam. Make sure that all the water has boiled off by the end of your trip. Do not expect a coaster brake to perform reliably or safely in hilly terrain. It's even possible to melt metal inside the hub. Also realize that if your chain derails or breaks, your coaster brake will no longer function.

How To Search/OhioLINK. OhioLINK Boolean Operators. See ../Millennium-III/ Other Operators. See ../Millennium-III/ Search Fields. See ../Millennium-III/

Organic Chemistry/Ketones and aldehydes. Aldehydes () and ketones () are both carbonyl compounds. They are organic compounds in which the carbonyl carbon is connected to conyl carbon satisfied by a H atom, while a ketone has both its vacancies satisfied by carbon. Naming Aldehydes and Ketones. Ketones are named by replacing the -e in the alkane name with -one. The carbon chain is numbered so that the ketone carbon, called the carbonyl group, gets the lowest number. For example, would be named 2-butanone because the root structure is butane and the ketone group is on the number two carbon. Alternatively, functional class nomenclature of ketones is also recognized by IUPAC, which is done by naming the substituents attached to the carbonyl group in alphabetical order, ending with the word ketone. The above example of 2-butanone can also be named ethyl methyl ketone using this method. If two ketone groups are on the same structure, the ending -dione would be added to the alkane name, such as heptane-2,5-dione. Aldehydes replace the -e ending of an alkane with -al for an aldehyde. Since an aldehyde is always at the carbon that is numbered one, a number designation is not needed. For example, the aldehyde of pentane would simply be pentanal. The -CH=O group of aldehydes is known as a formyl group. When a formyl group is attached to a ring, the ring name is followed by the suffix "carbaldehyde". For example, a hexane ring with a formyl group is named cyclohexanecarbaldehyde. Boiling Points and Bond Angles. Aldehyde and ketone polarity is characterized by the high dipole moments of their carbonyl group, which makes them rather polar molecules. They are more polar than alkenes and ethers, though because they lack hydrogen, they cannot participate in hydrogen bonding like alcohols, thus making their relative boiling points higher than alkenes and ethers, yet lower than alcohols. Typical bond angles between the carbonyl group and its substituents show minor deviations from the trigonal planar angles of 120 degrees, with a slightly higher bond angle between the O=C-R bond than the R-C-R bond on the carbonyl carbon (with R being any substituent). Preparing Aldehydes and Ketones. Preparing Aldehydes. Partial oxidation of primary alcohols to aldehydes. This reaction uses pyridinium chlorochromate (PCC) in the absence of water (if water is present the alcohol will be oxidized further to a carboxylic acid). From fatty acids. <chem>Ca(COOH)2 ->[\Delta] HCHO + CaCO3 </chem> <chem>(CH3COO)2Ca ->[\Delta] CH3COCH3 + CaCO3</chem> <chem>(CH3COO)2Ca + (HCOO)2Ca -> CH3CHO</chem> Stephen reduction. <chem>R-CN + SnCl2 + HCl -> R-CH=NH2+Cl- ->[H^+/H_2O] R-CHO </chem> Here sulfur is used as a poisoner so that aldehyde formed doesn't get oxidised to the carboxylic acid. See the Wikipedia article for more detail. Rosenmund reaction. <chem>R-COCl + Pd + BaSO4 + S -> R-CHO</chem> Preparing Ketones. From Grignard reagents. <chem>RCOOR' + R'MgX ->RCOR + R'OH</chem> R' R' OH <chem>RC=O + R'MgX -> R-CO-MgX -> R-C-OH + Mg-X</chem> O-R' OR' OR' From nitriles. RCN + R'MgX ----> RCOR'(after hydrolysis) HCN does not react with RMgX as HCN has acidic hydrogen which results in RH being formed. From gem dihalides. RCCl2R + strong base ----> RCOR Oppenaur oxidation. Reagent is Aluminium tert. butoxide solvent is acetone ROH + ACETONE ----> Ketone + isopropyl alcohol this oxidation does not affect double bonds in this oxidation ketone act as a oxidizing agent this is exact opposite to merrwine pondroff reduction Friedel-Crafts acylation of aromatic compounds. An aromatic ring reacts with a carboxylic acid chlorine (RCOCl) in the presence of AlCl3 to form an aryl ketone of the form ArCOR. Oxidation of secondary alcohols to ketones. A secondary alcohol can be oxidised into a ketone using acidified potassium dichromate(VI) and heating under reflux. The orange dichromate(VI) ion, Cr2O72-, is reduced to the green Cr3+(aq) ion. Ozonolysis of alkenes. It is a reaction in which the double bond is completely broken and the alkene molecule converted into two smaller molecules. Ozonolysis (cleavage "by ozone) is carried out in two stages: first, addition of ozone to the double bond to form an ozonide ; and second, hydrolysis of the ozonide to yield the cleavage products. Ozone gas is passed into a solution of the alkene in some inert solvent like carbon tetrachloride; evaporation of the solvent leaves the ozonide as a viscous oil. This unstable, explosive compound is not purified, but is treated directly with water, generally in the presence of a reducing agent. If oxidising reagent is used, aldehyde or ketone if oxidisable can further oxidise into carboxylic acid which is not the case with reducing agents In the cleavage products a doubly-bonded oxygen is found attached to each of the originally doubly-bonded carbons. The function of the reducing agent, which is frequently zinc dust, is to prevent formation of hydrogen peroxide, which would otherwise react with the aldehydes and ketones. (Aldehydes, RCHO, are often converted into acids,rCOOH, for ease of isolation.) Mechanism. The alkene and ozone form an intermediate molozonide in a 1,3-dipolar cycloaddition. Next, the molozonide reverts to its corresponding carbonyl oxide (also called the Criegee intermediate or Criegee zwitterion) and aldehyde or ketone in a retro-1,3-dipolar cycloaddition. The oxide and aldehyde or ketone react again in a 1,3-dipolar cycloaddition or produce a relatively stable ozonide intermediate (a trioxolane) Hydration of alkynes. Water is added to an alkyne in a strong acid. The strong acid used is sulfuric acid and mercuric acid. Keto-enol tautomerism. In the presence of an acid (H+) or a base (OH-), the aldehyde or ketone will form an equilibrium with enols, in which the double bond of the carbonyl group migrates to form double bond between the carbonyl and the alpha (α) carbon. In the presence of an acid, protonation of the oxygen group will occur, and water will abstract an alpha (α) hydrogen. In the presence of a base, deprotonation of the alpha hydrogen will occur, and a hydrogen from water will be abstracted by the carbonyl oxygen. This is an important feature of ketone and aldehydes, and is known as the "keto-enolic tautomery" or "keto-enol tautomerism", i.e. the equilibrium of carbonyl compounds between two forms. It must be stressed that the "keto" and the "enol" forms are two distinct compounds, not isomers. They are known as tautomers of each other. The presence of α-hydrogen is necessary for this equilibrium: those compounds not possessing it are called "non-enolizable" ketones. Reactions of Aldehydes and Ketones. Reactions with the carbonyl carbon. Since aldehydes and ketones contain a polar carbonyl group, the partially positive carbon atom can act as an electrophile. Strong and weak nucleophiles are able to attack this carbonyl carbon, resulting in a net addition to the molecule. Nucleophilic addition. With cyanide, nucleophilic addition occur to give a hydroxynitrile: RR'C=O + CN- + H+ → RR'COHCN e.g. propanone → 2-hydroxymethylpropanonitrile Reactions with the carbonyl oxygen. The partially negative oxygen can act as a nucleophile, or be attacked by electrophiles. Oxidation. Using a strong oxidizing agent such as the Tollens' Reagent (Ag2O in aqueous ammonia) acidified dichromate, Benedict's/Fehling's reagent (essentially alkaline Cu+2); aldehydes but not ketones may be oxidized into carboxylic acids. This is one way to test for the presence of an aldehyde in a sample compound: an aldehyde will become a carboxylic acid when reacted with Tollens' reagent, but a ketone will not react. when aldehydes react with fehling solution a red precipitate is obtained (due to formation of Cu2O) . Inductive Effect and Greek letter assignment. The carbonyl group is very electron withdrawing, and adjacent carbons are effected by induction. Using the carbonyl group as a reference, adjacent carbons are named using Greek letters in order of closeness to the carbonyl group. Alpha (α) carbons are directly attached to the carbonyl group, beta (β) carbons are connected to alpha carbons, gamma (γ) to beta (β), and so on. Due to the inductive effect of the partial positive especially prone to removal.

General Relativity/Geodesics. A is the generalization of a straight line for curved space. They deal largely with calculus of variations Metric Geodesics. A metric geodesic is defined as a curve along the shortest or longest possible distance between two points. Mathematically, it is defined as a curve whose length does not change with small variations that vanish at the endpoints. This stability could be a minimum distance, a maximum distance, or a point of inflection. Mathematically, a metric geodesic is defined by the curve Affine Geodesics. For instance on the surface of a sphere the shortest possible distance between two points is always the circumference of the sphere that runs through those two points. Those points on the sphere define exactly one "line" that runs through them. This line can't be said to be straight in the Euclidean sense of the word. However, for the curved surface of the sphere it represents the shortest possible distance and is therefore a metric geodesic of that space and represents a straight path for that space. Another possible geodesic for those two points is the other part of the circumference, which would be the longest path possible.

Amateur Radio Manual/Atoms. Note that this information is presented in very simplistic form for clarity. Atomic theory is much more complicated than most radio amateurs need to know but those that wish to know more should explore the other wiki books or wikipedia entries on the subject. =Atoms= The smallest building block of all matter is the atom (from the Greek Atomos). An atom is the smallest little bit that retains all the characteristics of the element it represents. For instance, if you had an atom of copper, and you cut it further, it would no longer retain the characteristics of copper. Atoms consist of smaller particles. In the nucleus, or centre of the atom, are neutrons and protons. Protons have a positive charge. Orbiting the nucleus of the atom are electrons that have a negative charge. [See Bohr atom. In simplest terms, electrons orbit the nucleus in orbits or shells. Each shell represents an energy state. The further from the nucleus, the more energetic the electron is. Each shell wants to contain a certain number of electrons to remain electrically stable. Neutral atoms have the same number of electrons and protons. This equal number is the atomic number of the element. Note that the terms positive and negative do not mean more and less in quantity but refer to the type of charge. What is interesting is that particles that have the same charge repel each other and particles that have opposite charges attract each other. If a proton meets an electron they join up to become a hydrogen atom, the simplest element. If you add electrons and protons (and a scattering of neutrons which are neutral) you create the various elements of the world around us. Now, lets look at the copper atom, because it is one of the best known conductors of electricity. Silver and platinum are better conductors, but cost too much for general use, unless you are building a satellite. Copper has an atomic number of 29. This tells us that there are 29 protons in the nucleus and 29 electrons arranges in shells or orbits around the nucleus. The first shell contains 2 ... leaving us 27 electrons, the next shell wants 8 ... leaving us 19 electrons ... the 3rd shell contains eighteen ... leaving us 1 electron for the 4th shell. Whoops.. the fourth shell wants 32 electrons. Electrons in an outer unfilled shell are known as valence electrons. It is possible to supply enough energy to the atom to overcome the electron's attraction to the nucleus and break it free from the atom. Most metals fall into this category. Because it only takes a little energy to break the electrons free, most metals are considered to be conductors. Elements that require a great deal of energy to break their electrons free are considered to be insulators.

Spanish/The Wrong Way To Learn Spanish. What is the Wrong Way to Learn Spanish? There are many ways to learn a language, such as: In the Wrong Way to Learn Spanish, we focus on learning by doing. It is there to be used as a guide rather than the main structured teaching of school-books. Most learning in The Wrong Way to Learn Spanish method takes the form of games and entertainment: trivia, live gameshows played by the student, role-playing, jokes, and stories. Because it's made based on fun-filled , learning Spanish in this way would be the same as a kid who is just having a good time, while building up one's knowledge on the Spanish vocabulary. Lesson 1: How to Learn New Vocabulary. Technique 1: Form Personal Mnemonics. Spanish words often bear little resemblance to their English counterparts. New Spanish students can overcome this by connecting the sound or spelling of a Spanish word to its meaning. Review the examples of one Spanish student below. Zorro (ZOHR-roh) means fox. Gato (GAH-toh) means cat. Perro (PEH-roh) means dog. Oso (OH-soh) means bear. Camarera (kah-mah-REH-rah) means waitress. Chico (CHEE-koh) means boy. Exercise 1.. <quiz display=simple> </quiz> Lesson 2. Five More Words. Vocabulary. Mesa (MEH-sah) means table. Falda (FAHL-dah) means skirt. Most countries in South America use the term "pollera" (poh-YAY-rah), which is less formal Agua (AH-gwah) means water. Cabeza (kah-BEH-sah) means head. Chica means girl. (CHEE-kah) Exercise 1.. <quiz display=simple> </quiz> Lesson 3. The Gender of Words. Words in Spanish have gender, which is the attribute of being masculine or feminine. In this sense, you can think about words being either boys or girls. Words that are masculine generally end in o and words that are female generally end in a. Two important exceptions are el día (day) and la mano (hand). Another way a teacher taught it was this: guys are LONERS and girls like DIJON mustard. Words ending in l, o, n, e, r and s are masculine. Words ending in d, i, a and sión are feminine. NOTE: It is true that there are exceptions to this, but if you have to guess at the gender of a word, it's a good method to try. Some important exceptions that are female are "mujer" means woman, "flor" means flower, "actriz" means actress, "emperatriz" means empress. Words "macho" and "hembra" don't have gender, it is used from gender of the noun. Exercise 1.. <quiz display=simple> +- chico -+ chica +- oso -+ falda -+ mesa +- zorro -+ camarera +- gato +- agua (for singular) -+ agua (for plural) +- perro -+ cabeza -+ mosquito hembra +- mosquito macho -+ flora -+ emperatriz -+ vaca Note that words like "lobo" can be either masculine or feminine. </quiz> Lesson 4. Your First Five Adjectives. Adjectives that don't change with the gender of the noun: Lesson 5. Masculine and Feminine "the". In English, we have one word for "the." In Spanish, there are four. Ah, but don't let this discourage you. After all, you already know three of them, and we are only going to be discussing two of them in this lesson. Continuing with the theme of words having gender, the word "the" in Spanish also has gender, depending on what the noun it is used with. Think of this like clothing. Boy words wear tuxedoes and girl words wear dresses. The tuxedo for boy words is "el". The dress for girl words is "la." (Yes, very feminine sounding.) "The" also has plurals (numbers three and four) which are "los" and "las". But we'll get to that later. Lesson 6. "Es" and Your First Complete Sentences. The word "es" is used as "is," for description of what something or someone is, looks like, or belongs to. Do not use it for location. e.g. La casa es grande. The house is big. e.g. El gato es feroz. The cat is fierce. The structure is article + noun + es + adjective. Remember to make the adjective agree with the noun! Test 1.. ["UNDER CONSTRUCTION"] Test everything presented so far, i.e. Lesson 1 exercises 1&2, Lesson 2 exercises 1&2, and Lesson 3 exercise 1. Paltalk Activity 1. Animal, Mineral, Vegetable. ["UNDER CONSTRUCTION?"] Tildes (Create of the original Espanol). The Tildes. Modes:

Of Mice and Men. "Of Mice and Men"' is a John Steinbeck novel set in the 1930s telling the story of migrant ranch workers and their dreams. The story focuses on two main characters, Lennie and George, who travel together. Lennie is a large, strong, mentally challenged man, while his friend, George, is small-framed, quick and intelligent. The name of the novel comes from a line contained in the second-to-last stanza of a famous poem written by Robert Burns called "To a Mouse" which summarizes very well what happens in the story. "The best laid schemes o' mice an' men" "Gang aft agley," "An' lea'e us nought but grief an' pain" "For promis'd joy." Further reading. __NOEDITSECTION__

Music Theory/Authors. If you added anything to this book, please feel free to enter either your nickname or full name to the list below: Thanks to all of those!

Swedish/Lesson 1. Swedes like to know to whom they are speaking, and this means that when speaking to a Swede, introductions are in order. While Swedish used to be more formal and included a strict use of titles indicating social, and marital status, this is completely abolished. Even very old people expect to be addressed as "du" "you" and only occasionally is "Ni" "you (plural)" used by sales clerks to address customers. The simplest way to greet a Swede is to establish eye-contact, followed by a simple "hej" "hi". It should not be confused with the English "hey", the use of which is more to attract attention, a meaning the Swedish greeting does not contain. A variation and more informal variant of this word is "hejsan". To show enthusiasm, you can repeat words; "hej hej". Shaking hands is the most common way of greeting a stranger in Sweden. More informal and friendly forms of greeting are the words "tja", "tjena" or "tjenare". Though more common among younger people, they are often used by considerably older speakers to establish familiarity or intimacy with the listener. "God dag" "good day" has a formal tone to it, but is very seldom used in everyday life, and is mostly seen in formal speeches and likewise. In the morning, "god morgon" "good morning", is commonly used and is not perceived as particularly formal, if polite. In the evening "god kväll" "good evening" can be used, but like "god dag" it's quite uncommon either with strangers or friends, but is entirely appropriate for a TV host to say in the introduction of a show. Dialogue. Two students are meeting in a university cafeteria in Sweden. One of them is Sven - a Swedish student - and the other one is Peter - an American exchange student. Sven: Hej. Hur mår du? <br> "English: Hi. How are you?" <br> Peter: Bara bra, tack. Förlåt, jag har glömt, var är du från? <br> "English: Just fine, thanks. Sorry, I have forgotten, where are you from?" <br> Sven: Jag är från Sverige, du då? <br> "English: I'm from Sweden, how about you?"<br> Peter: Jag är amerikan, jag är från USA. <br> "English: I am American, I'm from the USA." <br> Sven: Ja, just det! Förlåt, vad heter du igen? <br> "English: Oh, that's right! Sorry, what's your name again?" <br> Peter: Jag heter Peter och du heter Sven. <br> "English: My name is Peter and your name is Sven." <br> Sven: Tack. Vi ses! <br> "English: Thank you. See you later!" <br> Long and short vowels. Not unlike many other Scandinavian languages, Swedish distinguishes quite clearly between "long" and "short" vowels. English doesn't have the same clear distinction, but the phonetic sound differences are in the language. Compare for example the A in "haha" with the A in "heart," the former being short and the latter being long. The short A in "haha" matches the short Swedish A pretty well, as does the A in "heart" but with the long A. To distinguish long or short vowels in written language, the consonants immediately after the vowel are repeated to indicate a short vowel, and only written once to indicate a long. "Kommer" (coming) has a short O, because there are two M's, but it also has a short E, because more often than not, a word ends in a short vowel to aid in language flow when spoken. K is an exception to this rule, as you write "CK" when you want to indicate a short vowel. There are traces of a similar system in English, for example "rock" has a short O, compared to "rookie" which has a long O, but instead of letting the single consonant indicate a long O, "rookie" has two O's, unlike Swedish, where something along the lines of "rokie" would have been enough to say that the O is probably a long O. Phrases. Note that "hörs" and "ses" use a verb form that English does not have, a reciprocal form. It expresses a reciprocal action, signifying that people will hear from or see each other. Vocabulary. U.S. is USA (never US) in Swedish. It can also be called Amerikas Förenta Stater; and (very frequently) just Amerika. Family in Swedish parents -- föräldrar mother -- mamma / mor / moder Father -- pappa / far / fader son -- son daughter -- dotter Brother -- bror Sister -- syster Grandpa -- farfar / morfar grandma -- farmor / mormor grandson -- sonson / dotterson granddaughter -- sondotter / dotterdotter niece -- brorsdotter / systerdotter nephew -- brorson / systerson cousin -- kusin uncle -- farbror / morbror aunt -- faster / moster boy -- pojke girl -- flicka child /baby / infant -- barn / baby / bebis / spädbarn adult -- vuxen (n) man -- man woman -- kvinna Friend -- vän girlfriend -- väninna you can listen to this swedish vocabulary on its source on learnswedish.nu Exercise. Write a short dialogue, or practice with a friend. In the dialogue, use the phrases for greeting someone, telling them your name and where you're from. Finish it by using one of the phrases for telling the other person goodbye.

Message-Passing Interface. This guide assumes you have previous knowledge about C programming and will present you Message-Passing Interface (MPI) by several examples. What is MPI ? MPI is a standardized and portable message-passing system. Message-passing systems are used especially on distributed machines with separate memory for executing parallel applications. With this system, each executing process will communicate and share its data with others by sending and receiving messages. MPI is the specification resulting from the MPI-Forum which involved several organizations designing a portable system (that can allow programs to work on a heterogeneous network). Since the data can only be shared by exchanging messages, this standard is not intended for use on shared-memory systems, like a multiprocessor computer (although it will work, it is not the primary goal and there are more powerful alternatives, for instance, OpenMP). Basically, MPI includes point-to-point communication, collective communication (over a network of processes), process groups, bindings for Fortran and C and other advanced functions. On the other hand, the standard does not specify explicit shared-memory operations, debugging facilities, explicit support for threads, I/O functions. The current version is 2.0, although 1.1 is still used. Documentation. The volume Using MPI: Portable Parallel Programming with the Message-Passing Interface by William Gropp, Ewing Lusk and Anthony Skjellum is recommended as an introduction to MPI. For more complete information, read MPI: The Complete Reference by Snir, Otto, Huss-Lederman, Walker and Dongarra. Also, the standard itself can be found at or . For other Internet references, such as tutorials, see the Open Directory Project or the List of Tutorials at the Argonne National Laboratory. Implementation. Currently, there are two principal implementations: MPICH and LAM. The official web-site of the latter () contains much information about LAM and also about MPI. Supplementary library. Additionally libraries exist for solving numerical problem or for using I/O functions on a distributed machine. We can mention: the ScaLAPACK library, FFTW (a portable C FFT library), the PETSc Scientific Computing Libraries. A more complete list can be found on the site Developing tools. Compilers. Each implementation provides a compiler or at least a front-end to an existing compiler. Debugging. As MPI doesn't specify debugging facilities, some program can be used to this purpose: XMPI is a run/debug GUI for LAM/MPI; MPI-CHECK is a debugger for Fortran; Etnus, Inc. offers a version of the Totalview debugger that supports MPICH (as well as some other MPI implementations); and, Streamline Computing's Distributed Debugging Tool works with several MPI implementations, include MPICH and LAM/MPI. Benchmarks. Mpptest, SKaMPI and MPBench measure the performance of MPI implementations. They can be used to decide what implementation to use, how to implement portable and efficient MPI programs and also for predicting the performance of MPI programs. Famous and popular MPI benchmark includes NASA Parallel Benchmark, SpecMPI 2007 and HPCC benchmark suite. Applications. It can be used on large heterogeneous parc. Examples. Sum of an array. The point of this first simple example is to calculate the sum of all the value stored in an array. In C programming, the sequential version will be as below: /* Sum of an array - Sequential version */ #include <stdio.h> #define N 100000 int main (void) { float array[N]; double mysum = 0; unsigned long long i; //Initialization of the array for (i = 0; i < N; i++) array[i] = i + 1; //Calculation of the sum for (i = 0; i < N; i++) mysum += array[i]; printf ("%lf\n", mysum); return 0; First version - Basic point-to-point communications. MPI implementations allow a user to launch several processes which will each have a defined numerical identifier, its "rank". Conventionally, we will consider that the master is the process which has the rank '0'. All other processes are slaves. In this program, the master divides the array into sub-arrays and sends these to each slave. Each slave will then calculate the sum of its sub-array. In the case where the size of the array is not an even multiple of the number of slaves, the master will finish the remaining work by calculating the sum of the last values of the array (see figure below). For each process, the source code of the program is identical and thus the executable code is, also. The code therefore must contain both the slave and the master parts. The part that will be executed depends on the rank of the process. In this first version, the work is divided into just two parts: /* Sum of an array - First parallel version */ #include <stdio.h> #include <mpi.h> #define N 100000 #define MSG_DATA 100 #define MSG_RESULT 101 void master (void); void slave (void); int main (int argc, char **argv) { int myrank; //Initialization of MPI MPI_Init (&argc, &argv); //myrank will contain the rank of the process MPI_Comm_rank (MPI_COMM_WORLD, &myrank); //The part of the program which will be executed is decided if (myrank == 0) master (); else slave (); MPI_Finalize (); return 0; void master (void) { float array[N]; double mysum = 0, tmpsum; unsigned long long i; MPI_Status status; //Initialization of the array for (i = 0; i < N; i++) array[i] = i + 1; //The array is divided by two and each part is sent to the slaves MPI_Send (array, N / 2, MPI_FLOAT, 1, MSG_DATA, MPI_COMM_WORLD); MPI_Send (array + N / 2, N / 2, MPI_FLOAT, 2, MSG_DATA, MPI_COMM_WORLD); //The master receive the result from the slaves MPI_Recv (&tmpsum, 1, MPI_DOUBLE, 1, MSG_RESULT, MPI_COMM_WORLD, &status); mysum += tmpsum; MPI_Recv (&tmpsum, 1, MPI_DOUBLE, 2, MSG_RESULT, MPI_COMM_WORLD, &status); mysum += tmpsum; printf ("%lf\n", mysum); void slave (void) { float array[N]; double sum; unsigned long long i; MPI_Status status; //The slave receives the array from the master MPI_Recv (array, N / 2, MPI_FLOAT, 0, MSG_DATA, MPI_COMM_WORLD, &status); for (i = 0, sum = 0; i < N / 2; i++) sum += array[i]; //The result is send to the master MPI_Send (&sum, 1, MPI_DOUBLE, 0, MSG_RESULT, MPI_COMM_WORLD); This program will be explained step by step. First, for using MPI functions, we must include the file codice_1 which contains the prototypes of the required functions. The size of the array is next defined by codice_2. codice_3 and codice_4 will be used by the codice_5 and the codice_6 functions. Two prototypes of functions are declared. These functions contain the code for the master process and for the slave processes, respectively. The main function chooses whether it should execute the master part (if the process rank is 0) or the slave part (for any other process rank.) The function begins with the codice_7 routine that must be called before any other MPI functions. This routine performs various initialization functions. Next, the rank of the process is obtained by calling the codice_8 function and, depending on the result, the master part or the slave part is executed. At the end of the computation, the final routine codice_9 is called. It performs various administrative tasks associated with ending the use of MPI. Two declarations not found in the sequential version of the program are included in the master: the codice_10variable, which will store the result in each of the two slaves, and the codice_11 variable (whose type is defined by MPI), which is needed by the codice_6 function. The computation part is now replaced by two calls to codice_13 and codice_6. The arguments of the codice_13 function are the address of the first element to send, the number of elements to send, their type (the more common MPI types are codice_16, codice_17, codice_18, codice_19, ...), the rank of the receiver, the tag of the message, and the communicator. In the simplest usage, the communicator would be codice_20, which includes all the processes sharing in the execution of the program. The arguments of the codice_6 function are the address of the receive buffer, the maximum number of elements to receive, their type, the rank of the sender, the tag of the message, communicator, and the status. For a common message, the type, the tag and the communicator must be the same (see figure below). The first half of the array is sent to the first slave and the second half of the array is sent to the second. In each case, the size of the sub-array is codice_22. Next, the result is received from the slaves, stored, and added to the final sum. Before it can receive the computed sums from the slaves, however, each slave must first sum the elements of the sub-array it has received from the master. The slave then sends the result back to the master. When several messages are sent to the same process in an arbitrary order, the tag argument allow this process to distinguish between these messages and to receive them. For execute this program with a lam implementation, the lam daemon must be started: $ lamboot Next, mpicc and mpirun are used for the compilation and the execution: $ mpicc ./source.c $ mpirun -np 3 ./a.out The option -np specifies the number of processes to launch. In this example, it must be three (one master, two slaves). The program codice_23 creates an MPI environment, copying codice_24 to all three processors and running each one with the appropriate processor number set. Second version - Adaptiveness to the number of processes. This basic program has two problems: This leads to this second version: /* Sum of an array - Second parallel version */ #include <stdio.h> #include <mpi.h> #define N 100000 #define MSG_DATA 100 #define MSG_RESULT 101 void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; void master (void) { float array[N]; double mysum, tmpsum; unsigned long long step, i; int size; MPI_Status status; //Initialization of the array for (i = 0; i < N; i++) array[i] = i + 1; MPI_Comm_size (MPI_COMM_WORLD, &size); if (size != 1) step = N / (size - 1); //The array is divided by the number of slaves for (i = 0; i < size - 1; i++) MPI_Send (array + i * step, step, MPI_FLOAT, i + 1, MSG_DATA, MPI_COMM_WORLD); //The master completes the work if necessary for (i = (size - 1) * step, mysum = 0; i < N; i++) mysum += array[i]; //The master receives the results in any order for (i = 1; i < size; mysum += tmpsum, i++) MPI_Recv (&tmpsum, 1, MPI_DOUBLE, MPI_ANY_SOURCE, MSG_RESULT, MPI_COMM_WORLD, &status); printf ("%lf\n", mysum); void slave (void) { float array[N]; double sum; unsigned long long i; int count; MPI_Status status; MPI_Recv (array, N, MPI_FLOAT, 0, MSG_DATA, MPI_COMM_WORLD, &status); //The slave finds the size of the array MPI_Get_count (&status, MPI_FLOAT, &count); for (i = 0, sum = 0; i < count; i++) sum += array[i]; MPI_Send (&sum, 1, MPI_DOUBLE, 0, MSG_RESULT, MPI_COMM_WORLD); For the first issue, the master needs the number of processes to determinate the size of the sub-array (which will be stored in the step variable). The codice_25 function gives this indication in the size variable, so codice_2 is divided by the number of slaves, namely codice_27−1 . The array is next sent to slave and while the slave will compute, the master will finish the work if it is necessary. It will then receive the result and add these to the final sum. For solving the second issue, the master will receive result from any source. This leads to the use of MPI_ANY_SOURCE in the codice_28 function in place of the rank of the process. The slave does not need to know the number of processes but does the size of the sub-array that it has received. For this we will use the status argument. Actually, status is a structure that contains three data: the source of the message (useful if codice_29 is used), the tag of the message (if codice_30 is used), and the error code. Additionally, we can access to the real length of the received data by using the codice_31 function and the status argument. The count variable is the length of the sub-array. This version of the program can be used with any number of processes, even 1. In this special case, the master will do all the calculations. Unfortunately, this program is not adapted to MPI because, there is a lot of data transfer and a little computation. While MPI is designed for non-shared memory operation, there must be more computation than data transferring for losing the less possible time in message. We could improve this program by sending only the first number and the last to sum (and to add all integer between these), but in this case only geometric sum can be calculated. Integration by the. The purpose of this program is to calculate the integral of a given function by the . This example is more adapting to MPI, because it requires more computation and less data-transferring than previously. The mathematical equation is: formula_1 In C programming, the sequential version is: /* Integration - Simpson method - Sequential version */ #include <stdio.h> #include <math.h> #define n 10000 //Must be even double f (double x); int main (void) { double integration,step; int i; printf ("Enter the domain of integration: "); scanf ("%lf %lf", &a, &b); step = (b - a) / n; for (i = 1, integration = 0; i < n / 2; i++) integration += 2*f(a+(2*i-1)*step) + f(a+2*i*step); integration *= 2; integration += f(a) + f(b) + 4*f(b - step); integration *= step / 3; printf ("%.15lf\n", integration); return 0; double f (double x) { return exp(-1*pow(x,2)); First version - User-defined type. The work to be done is a sum like in the precedent example (an array with different coefficient to each boxes). The work will be divided as shown in the figure below. The sum is divided and calculated by the slave and the master calculate the other values and complete the work if necessary as before. The domain of the sum will be sent to each slave and they will evaluate several return values of the function and sum these. The information that will be sent are the beginning of the sum (begin), the difference between each value (step) and the number of value for which the function must be evaluated (two double and one integer). However, the data send by the codice_5 routine must have the same type. Then, for minimizing the number of message to send and so for optimizing the program, a MPI type will be created and used for sending these data. Generally, the data to send must be grouped and minimized for reducing the time wasted in communication (sending the minimum of message and with the minimum of data). So, two integer must be stored in a array and sent in a unique message rather than sent in two different messages. Since the division of the work is faster than the work it-self, when a few processes are used, the master will wait a relatively long time for the result of the slaves. In this program, when there is less than a defined number of processes (LIMIT_PROC), the master will participate to the computation (namely, the work will be divided by the number of processes rather than the number of slave). /* Integration - Simpson method - First parallel version */ #include <stdio.h> #include <math.h> #include <mpi.h> #define n 10000 //Must be even #define LIMIT_PROC 4 //Number of process for which the master stop to work and only divide the work #define MSG_DATA 100 #define MSG_RESULT 101 struct domain_of_sum { double begin; double step; int number; //Number of iteration double f (double x); MPI_Datatype Init_Type_Domain (void); //Declaration of a MPI type which will contain the domain void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; MPI_Datatype Init_Type_Domain (void) { MPI_Datatype Domain; MPI_Datatype type[3] = { MPI_DOUBLE, MPI_DOUBLE, MPI_INT }; int blocklen[3] = { 1, 1, 1 }; MPI_Aint ext; MPI_Type_extent (MPI_DOUBLE, &ext); MPI_Aint disp[3] = { 0, ext, 2 * ext }; MPI_Type_struct (3, blocklen, disp, type, &Domain); return Domain; void master (void) { double integration, a, b, sum; int i, size; struct domain_of_sum mydomain; //The C structure which will contain the domain MPI_Status status; MPI_Datatype Domain = Init_Type_Domain (); //Creation of the MPI type MPI_Type_commit (&Domain); MPI_Comm_size (MPI_COMM_WORLD, &size); printf ("Enter the domain of integration: "); scanf ("%lf %lf", &a, &b); mydomain.step = (b - a) / n; //step of the integration //The work is divided if (size > 1) { if (size > LIMIT_PROC) mydomain.number = (n / 2 - 1) / (size - 1); else mydomain.number = (n / 2 - 1) / size; mydomain.begin = a + mydomain.step; //Each domain are sent for (i = 0; i < size - 1; i++) { mydomain.begin = a + (2 * i * mydomain.number + 1) * mydomain.step; MPI_Send (&mydomain, 1, Domain, i + 1, MSG_DATA, MPI_COMM_WORLD); //The master complete the work for (i = (size - 1) * mydomain.number + 1, integration = 0; i < n / 2; i++) integration += 2 * f (a + (2 * i - 1) * mydomain.step) + f (a + 2 * i * mydomain.step); //The master receive the result for (i = 1; i < size; i++) { MPI_Recv (&sum, 1, MPI_DOUBLE, MPI_ANY_SOURCE, MSG_RESULT, MPI_COMM_WORLD, &status); integration += sum; integration *= 2; integration += f (a) + f (b) + 4 * f (b - mydomain.step); integration *= mydomain.step / 3; printf ("%.15lf\n", integration); void slave (void) { double sum; int i; struct domain_of_sum mydomain; MPI_Status status; MPI_Datatype Domain = Init_Type_Domain (); //Creation of the MPI type MPI_Type_commit (&Domain); MPI_Recv (&mydomain, 1, Domain, 0, MSG_DATA, MPI_COMM_WORLD, &status); for (i = 0, sum = 0; i < mydomain.number; i++) sum += 2*f(mydomain.begin+(2*i)*mydomain.step) + f(mydomain.begin+(2*i+1)*mydomain.step); MPI_Send (&sum, 1, MPI_LONG_LONG_INT, 0, MSG_RESULT, MPI_COMM_WORLD); All the routine used for creating the MPI type are regrouped in the function Init_Type_Domain for simplifying the code. The function codice_33 is used for creating the new type and store it in Domain. This function need 5 arguments: the number of blocks that the new type will contain (in this case two doubles and one integer); the number of each elements of these blocks in an array (one double, another double and one integer); an array of the displacement of each block in the message; an array of these types; and, the address of the variable which will contain the structure. The displacement of each blocks is obtained by the use of the codice_34 function which give the length of a codice_19. It is the equivalent to the codice_36 function in C. The length of a MPI type is store in a codice_37 variable. An other possibility would be to declare a structure that contains a array of two doubles and a integer: struct domain_of_sum { double array[2]; //Contains begin and step int number; //The new MPI type MPI_Datatype Init_Type_Domain (void) { MPI_Datatype Domain; MPI_Datatype type[2] = { MPI_DOUBLE, MPI_INT }; int blocklen[2] = { 2, 1 }; MPI_Aint ext; MPI_Type_extent (MPI_DOUBLE, &ext); MPI_Aint disp[2] = { 0, 2 * ext }; MPI_Type_struct (2, blocklen, disp, type, &Domain); return Domain; Second version. Two different methods have been used for determining the number of operations that the slave must realize. In the first example, the slave use the status argument of the codice_28 function. In the second, this number was directly sent with the data. An other way is to obtain this by the same way that the master fixed this data, namely with the number of processes. For minimizing the quantity of data-transfer, we will use this last method (this version is just a optimization): /* Integration - Simpson method - Second parallel version*/ #include <stdio.h> #include <math.h> #include <mpi.h> #define n 10000 #define LIMIT_PROC 4 #define MSG_DATA 100 #define MSG_RESULT 101 double f (double x); int Get_the_number (int size); // Function which gives the number of iterations void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; int Get_the_number (int size) { int number; if (size > 1) { if (size > LIMIT_PROC) number = (n / 2 - 1) / (size - 1); else number = (n / 2 - 1) / size; return number; void master (void) { double integration, a, b, sum; int i, size, number; double mydomain[2]; MPI_Status status; MPI_Comm_size (MPI_COMM_WORLD, &size); number = Get_the_number (size); printf ("Enter the domain of integration: "); scanf ("%lf %lf", &a, &b); mydomain[1] = (b - a) / n; //The work is divided mydomain[0] = a + mydomain[1]; for (i = 0; i < size - 1; i++) { mydomain[0] = a + (2 * i * number + 1) * mydomain[1]; MPI_Send (mydomain, 2, MPI_DOUBLE, i + 1, MSG_DATA, MPI_COMM_WORLD); //The master complete the work for (i = (size - 1) * number + 1, integration = 0; i < n / 2; i++) integration += 2 * f (a + (2 * i - 1) * mydomain[1]) + f (a + 2 * i * mydomain[1]); //The master receive the result for (i = 1; i < size; i++) { MPI_Recv (&sum, 1, MPI_DOUBLE, MPI_ANY_SOURCE, MSG_RESULT, MPI_COMM_WORLD, &status); integration += sum; integration *= 2; integration += f (a) + f (b) + 4 * f (b - mydomain[1]); integration *= mydomain[1] / 3; printf ("%.15lf\n", integration); void slave (void) { double sum; int i, size, number; double mydomain[2]; MPI_Status status; MPI_Comm_size (MPI_COMM_WORLD, &size); number = Get_the_number (size); MPI_Recv (mydomain, 2, MPI_DOUBLE, 0, MSG_DATA, MPI_COMM_WORLD, &status); for (i = 0, sum = 0; i < number; i++) sum+=2*f(mydomain[0]+(2*i)*mydomain[1])+f(mydomain[0]+(2*i+1)*mydomain[1]); MPI_Send (&sum, 1, MPI_DOUBLE, 0, MSG_RESULT, MPI_COMM_WORLD); Product of a vector and a matrix. The point of this program is to calculate the product of a vector and a matrix. In C programming, the sequential version is: /* Product of a vector by a matrix - Sequential version */ #include <stdio.h> #include <mpi.h> #define N 10000 void writecolumn (float *A); int main (int argc, char **argv) { float *A = (float *) malloc (N * N * sizeof (float)), B[N], C[N]; unsigned int i, j, step; int size; //Initialization for (i = 0; i < N; i++) { for (j = 0; j < N; j++) *(A + i * N + j) = i + j; B[i] = 1; //Product of the matrix and the vector for (i = 0; i < N; ++i) for (j = 0, C[i] = 0; j < N; j++) C[i] += *(A + i * N + j) * B[j]; writecolumn(C); free (A); return 0; void writecolumn (float *A) { int i; for (i = 0; i < N; i++) printf ("%f\n", *(A + i)); First version - Broadcast. For parallelizing this program, the matrix will be divide by groups of lines and each part will be sent to a different slave while the vector will be sent to every slave (see figure below). Sending the same data to each slave can be done by broadcasting these data with the codice_39 function which must be called by all the processes. /* Product of a vector by a matrix - First parallel version */ #include <stdio.h> #include <mpi.h> #define N 10000 #define LIMIT_PROC 4 #define MSG_DATA 100 #define MSG_RESULT 101 void writecolumn (float *A); int Get_the_number (int size); void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; int Get_the_number (int size) { int number; if (size > 1) { if (size > LIMIT_PROC) number = N / (size - 1); else number = N / size; return number; void master (void) { float *A = (float *) malloc (N * N * sizeof (float)), B[N], C[N], *buff; unsigned int i, j, step; int size; MPI_Status status; //Initialization for (i = 0; i < N; i++) { for (j = 0; j < N; j++) *(A + i * N + j) = i + j; B[i] = 1; //Division of work MPI_Comm_size (MPI_COMM_WORLD, &size); step = Get_the_number (size); //Broadcast of the vector MPI_Bcast (B, N, MPI_FLOAT, 0, MPI_COMM_WORLD); for (i = 1; i < size; i++) MPI_Send (A + (i - 1) * step * N, N * step, MPI_FLOAT, i, MSG_DATA, MPI_COMM_WORLD); //Finishing the work for (i = (size - 1) * step; i < N; ++i) for (j = 0, C[i] = 0; j < N; j++) C[i] += *(A + i * N + j) * B[j]; buff = (float *) malloc (step * sizeof (float)); //Receive and reorder for (i = 1; i < size; i++) { MPI_Recv (buff, step, MPI_FLOAT, MPI_ANY_SOURCE, MSG_RESULT, MPI_COMM_WORLD, &status); for (j = 0; j < step; j++) C[j + (status.MPI_SOURCE - 1) * step] = buff[j]; writecolumn(C); free (A); free (buff); void slave (void) { float Vect[N]; unsigned int i, j, step; int size; MPI_Status status; MPI_Comm_size (MPI_COMM_WORLD, &size); step = Get_the_number (size); float *result = (float *) malloc (step * sizeof (float)); float *partmat = (float *) malloc (step * N * sizeof (float)); MPI_Bcast (Vect, N, MPI_FLOAT, 0, MPI_COMM_WORLD); MPI_Recv (partmat, N * step, MPI_FLOAT, 0, MSG_DATA, MPI_COMM_WORLD, &status); for (i = 0; i < step; ++i) for (j = 0, result[i] = 0; j < N; j++) result[i] += Vect[j] ** (partmat + i * N + j); MPI_Send (result, step, MPI_FLOAT, 0, MSG_RESULT, MPI_COMM_WORLD); free (partmat); free (result); The codice_39 function requires fewer arguments than the codice_5 and the codice_28 functions. The codice_39 function requires the address of the buffer that contains or will contain the broadcasting data, the number of entries in the buffer, these type, the rank of the broadcast root (the process that will send the data) and the communicator. There are neither tag nor status arguments because they serve to differentiate messages and to give information about the receiving data and in this case, all processes are involved in the broadcast message (so, there is no need to differentiate message) and the information stored in status are known (the source is the broadcast root, the length is the number of entries and there is no tag). When the master receive the data, it must reorder it because the order of receiving is not specified (codice_29). For this purpose, the status structure contains the source of the message which is used for reordering and composing the vector. In this example, the matrix is stored in a one-dimensional array in place of a conventional two-dimensinal array. It is possible to send a multi-dimensional array with MPI, but it must be carefully allocated. Namely, the array must be stored contiguously because the first argument of sent functions is the address of the starting buffer, and the second argument specifies the number of the following values that will be sent. Then the static and dynamic allocation are: /* Static allocation */ int array[rows][columns]; /* Dynamic allocation */ int **array; array = (int**) malloc (rows * sizeof(int*)); if (array == NULL) exit (-1); array[0] = (int*) malloc (rows * columns * sizeof(int)); if (array[0] == NULL) exit (-1); for (i=1; i<rows; i++) array[i] = array[0] + i * columns; /* Send either kind of array */ MPI_Send (array[0],rows*columns,MPI_INT,0,0,MPI_COMM_WORLD); Second version - Scatter and gather. The MPI specification provides collective communication functions, and the codice_39 function is one of these. The next version of this program will use the "scatter" and "gather" functions which, respectively, send different data to everyone and receive different data from everyone (see figure below). Thus, the work will be divided a little differently, namely, the master will also participate in the computation. /* Product of a vector by a matrix - Second parallel version */ #include <stdio.h> #include <stdlib.h> #include <mpi.h> #define N 5000 #define MSG_DATA 100 #define MSG_RESULT 101 void writecolumn (float *A); void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; void master (void) { float *A = (float *) malloc (N * N * sizeof (float)), B[N], C[N]; unsigned int i, j, step; int size; MPI_Status status; //Initialization for (i = 0; i < N; i++) { for (j = 0; j < N; j++) *(A + i * N + j) = i + j; B[i] = 1; //Division of the work MPI_Comm_size (MPI_COMM_WORLD, &size); step = N / size; float *result = (float *) malloc (step * sizeof (float)); float *partmat = (float *) malloc (step * N * sizeof (float)); //Sending the data MPI_Bcast (B, N, MPI_FLOAT, 0, MPI_COMM_WORLD); //Each processes will receive a different part of the matrix MPI_Scatter (A, N * step, MPI_FLOAT, partmat, N * step, MPI_FLOAT, 0, MPI_COMM_WORLD); //The master make its part (the same code is used for the slaves) for (i = 0; i < step; ++i) for (j = 0, result[i] = 0; j < N; j++) result[i] += *(partmat + i * N + j) * B[j]; //It finish the work for (i = size * step; i < N; ++i) for (j = 0, C[i] = 0; j < N; j++) C[i] += *(A + i * N + j) * B[j]; //Receiving the data in the good order MPI_Gather (result, step, MPI_FLOAT, C, step, MPI_FLOAT, 0, MPI_COMM_WORLD); writecolumn(C); free (partmat); free (result); free (A); void slave (void) { float Vect[N], *A, *C; //C and A are not used by slaves but must be declared unsigned int i, j, step; int size; MPI_Comm_size (MPI_COMM_WORLD, &size); step = N / size; float *result = (float *) malloc (step * sizeof (float)); float *partmat = (float *) malloc (step * N * sizeof (float)); //Receiving the data MPI_Bcast (Vect, N, MPI_FLOAT, 0, MPI_COMM_WORLD); MPI_Scatter (A, N * step, MPI_FLOAT, partmat, N * step, MPI_FLOAT, 0, MPI_COMM_WORLD); //Computation for (i = 0; i < step; ++i) for (j = 0, result[i] = 0; j < N; j++) result[i] += Vect[j] ** (partmat + i * N + j); //Sending the result MPI_Gather (result, step, MPI_FLOAT, C, step, MPI_FLOAT, 0, MPI_COMM_WORLD); free (partmat); free (result); void writecolumn (float *A) { int i; for (i = 0; i < N; i++) printf ("%f\n", *(A + i)); The call to the functions MPI_SCATTER and MPI_GATHER is the same for the master as for the slaves ("emphasized arguments" are ignored by the slaves). The arguments are: Note that in the first case, the master sends data to itself and in the second, it receives data from itself. In this example, the matrix is divided by the number of processes and the master sends the first part to itself, the second part to the first slave, etc. Afterwards the master receives the first part of the resulting vector from itself, the second from the first slave, etc. Cellular automata. In this example, we will code a cellular automata. A cellular automata is the evolution of a matrix on which we execute a defined function until there is convergence or cyclic phenomena. The function return a value for each point of the matrix depending of the value of his four neighbors. The border of the matrix will have the same value than the border of there opposite side. The resulting matrix will be a torus. In C programming, the sequential version is: /* Cellular automata - Sequential version */ #include <stdio.h> #include <stdlib.h> #define N 62 #define MAX_ITERATION N //Number of iteration void init_mat (int *A, int length); void writemat (int *A); int f (int x1,int x2,int x3,int x4); int main (int argc, char **argv) { int* A=(int*)malloc(N*N*sizeof(int)); int* B=(int*)malloc((N-2)*(N-2)*sizeof(int)); int i,j,k=0; init_mat (A,N); while(k++<MAX_ITERATION) { //Calculation of the new matrix in a temporary matrix for (i=0;i<N-2;i++) for (j=0;j<N-2;j++) *(B+i*N+j)=f(*(A+(i+1)*N+j),*(A+(i+1)*N+j+2),*(A+i*N+j+1),*(A+(i+2)*N+j+1)); //Copy of the new matrix for (i=1;i<N-1;i++) for (j=1;j<N-1;j++) *(A+i*N+j)=*(B+(i-1)*N+j-1); //Update of the border for (i=1;i<N-1;i++) { *(A+i)=*(A+(N-2)*N+i); *(A+(N-1)*N+i)=*(A+N+i); *(A+i*N)=*(A+i*N+N-2); *(A+i*N+N-1)=*(A+i*N+1); writemat(A); return 0; void init_mat (int *A, int length) { int i,j; for (i=0;i<length;i++) for (j=0;j<length;j++) *(A+i*length+j)=i+j>length/2&&i+j<length*3/2; //Each border of the matrix will have the same value than the border of his opposite side for (i=1;i<length-1;i++) { *(A+i)=*(A+(length-2)*length+i); *(A+(length-1)*length+i)=*(A+length+i); *(A+i*length)=*(A+i*length+length-2); *(A+i*length+length-1)=*(A+i*length+1); void writemat (int *A) { int i,j; for (i = 0; i < N; i++) { for (j = 0; j < N; j++) printf ("%d ", *(A + i*N +j)); printf("\n"); int f (int x1,int x2,int x3,int x4) { return x1+x2+x3+x4>2; First version - Deadlock. The matrix will be divided by group of lines like in the figure [fig:vect]. For calculating the new part of the matrix, the functions applied need the values of points that belong to other parts of the matrix and then, each process will calculate the new matrix and exchange the first line and the last line with its two neighbors (see figure below). While the processes share their data, a dead-lock can occur. A deadlock is a blocking state of a program due to the fact that one process is waiting for a specific action to be taken by another process, but the latter process is waiting for a specific action to be taken by the former process. This phenomena leads to a permanent waiting state (see figure below). A deadlock can occur in this code because the MPI_SEND and MPI_RECV functions block the program until they are completed, namely, until the receiver receives the message sent or the sender sends the message to be received. If all the processes perform the same code (excluding the master), process one will send data to process two, process two will send data to process three, etc. Process one will wait until process two receives its data, but this will never happen because process two is also waiting until process three receives its data. Because the communication is cyclic, the program is blocked. As a first solution, we can change the order of sending and receiving on each even process. /* Cellular automata - First parallel version */ #include <stdio.h> #include <stdlib.h> #include <mpi.h> #define N 62 //Must be multiple of number of processes (which must be > 1) #define MAX_ITERATION N #define MSG_DATA 100 void init_mat (int *A, int length); void writemat (int *A, int length); int f (int x1,int x2,int x3,int x4); int main (int argc, char **argv) { int* result=(int*)malloc(N*N*sizeof(int)); int* A=(int*)malloc(N*N*sizeof(int)); int* tmp=(int*)malloc((N-2)*(N-2)*sizeof(int)); int step; int myrank,size,left,right; MPI_Status status; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); MPI_Comm_size (MPI_COMM_WORLD, &size); int i,j,k=0; step = (N-2)/size; //Initialization by the master if (!myrank) init_mat(result,N); MPI_Scatter (result+N,step*N,MPI_INT,A+N,step*N,MPI_INT,0,MPI_COMM_WORLD); //The next and the previous processes are determined left=(myrank-1+size)%size; right=(myrank+1)%size; while(k++<MAX_ITERATION) { //The order of exchanging the data is decided if (myrank%2) { MPI_Send (A+N,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD); MPI_Recv (A+(step+1)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD,&status); MPI_Send (A+(step)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD); MPI_Recv (A,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,&status); } else { MPI_Recv (A+(step+1)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD,&status); MPI_Send (A+N,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD); MPI_Recv (A,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,&status); MPI_Send (A+(step)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD); for (i=1;i<step-1;i++) { *(A+i*N)=*(A+i*N+N-2); *(A+i*N+N-1)=*(A+i*N+1); for (i=0;i<step;i++) for (j=0;j<N-2;j++) *(tmp+i*N+j)=f(*(A+(i+1)*N+j),*(A+(i+1)*N+j+2),*(A+i*N+j+1),*(A+(i+2)*N+j+1)); for (i=1;i<step+1;i++) for (j=1;j<N-1;j++) *(A+i*N+j)=*(tmp+(i-1)*N+j-1); MPI_Gather (A+N,step*N,MPI_INT,result+N,step*N,MPI_INT,0,MPI_COMM_WORLD); //The master recompose the matrix and print it if (!myrank) { for (i=1;i<N-1;i++) { *(result+i)=*(result+(N-2)*N+i); *(result+(N-1)*N+i)=*(result+N+i); *(result+i*N)=*(result+i*N+N-2); *(result+i*N+N-1)=*(result+i*N+1); writemat(result,N); MPI_Finalize (); return 0; In this example, the master and the slave have almost the same code, so it is not necessary to divide the code in two functions (the code specific to the master is simply be preceded by a condition on the rank). While the master wait for data from the process 1, the process 1 send data to the master. Then it wait for data from the master while this one send data to its. The code will have the same behavior for all processes and thus is safe. Second version - Non-blocking send and receive. A second solution is to use non-blocking send and receive: these functions are called and give immediately the hand to the process. Then, the process can make some computation and when the data of the message need to be accessed, it can completed it by calling some appropriate functions. Program using non-blocking communication functions can be faster. In this second version, all the functions will be completed just after that all send and all receive are begun. In the previous example, the dimension of the matrix should be a multiple of the number of processes because the remaining lines were not send to any process. In this version, the master send these lines to the last process and receive the resulting line separately. /* Cellular automata - Second parallel version */ #include <stdio.h> #include <stdlib.h> #include <mpi.h> #define N 62 //Must be multiple of number of processes #define MAX_ITERATION N #define MSG_DATA 100 void init_mat (int *A, int length); void writemat (int *A, int length); int f (int x1,int x2,int x3,int x4); int main (int argc, char **argv) { int* result=(int*)malloc(N*N*sizeof(int)); int* A=(int*)malloc(N*N*sizeof(int)); int* tmp=(int*)malloc((N-2)*(N-2)*sizeof(int)); int step; int myrank,size,left,right; MPI_Status status; MPI_Request request[4]; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); MPI_Comm_size (MPI_COMM_WORLD, &size); int i,j,k=0; step = (N-2)/size; if (!myrank) init_mat(result,N); MPI_Scatter (result+N,step*N,MPI_INT,A+N,step*N,MPI_INT,0,MPI_COMM_WORLD); //Code allowing any dimension of the matrix if (myrank==0&&(N-2)%size) MPI_Send (result+N*(step*size+1),(N-2-step*size)*N,MPI_INT,size-1,MSG_DATA,MPI_COMM_WORLD); else if (myrank==size-1&&(N-2)%size) { MPI_Recv (A+N*(step+1),(N-2-step*size)*N,MPI_INT,0,MSG_DATA,MPI_COMM_WORLD,&status); step+=N-2-step*size; left=(myrank-1+size)%size; right=(myrank+1)%size; while(k++<MAX_ITERATION) { //The data begin to be shared MPI_Isend (A+N,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,request); MPI_Irecv (A+(step+1)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD,request+1); MPI_Isend (A+(step)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD,request+2); MPI_Irecv (A,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,request+3); //The transfer of data are completed for (i=0;i<4;i++) MPI_Wait(request+i,&status); for (i=1;i<step-1;i++) { *(A+i*N)=*(A+i*N+N-2); *(A+i*N+N-1)=*(A+i*N+1); for (i=0;i<step;i++) for (j=0;j<N-2;j++) *(tmp+i*N+j)=f(*(A+(i+1)*N+j),*(A+(i+1)*N+j+2),*(A+i*N+j+1),*(A+(i+2)*N+j+1)); for (i=1;i<step+1;i++) for (j=1;j<N-1;j++) *(A+i*N+j)=*(tmp+(i-1)*N+j-1); if (myrank==size-1&&(N-2)%size) { step=(N-2)/size; MPI_Send (A+N*(step+1),(N-2-step*size)*N,MPI_INT,0,MSG_RESULT,MPI_COMM_WORLD); } else if (myrank==0&&(N-2)%size) MPI_Recv (result+N*(step*size+1),(N-2-step*size)*N,MPI_INT,size-1,MSG_RESULT,MPI_COMM_WORLD,&status); MPI_Gather (A+N,step*N,MPI_INT,result+N,step*N,MPI_INT,0,MPI_COMM_WORLD); if (!myrank) { for (i=1;i<N-1;i++) { *(result+i)=*(result+(N-2)*N+i); *(result+(N-1)*N+i)=*(result+N+i); *(result+i*N)=*(result+i*N+N-2); *(result+i*N+N-1)=*(result+i*N+1); writemat(result,N); MPI_Finalize (); return 0; The MPI_Isend and the MPI_Irecv (I means immediate) functions need a supplementary argument: the address of a MPI_Request variable which will identify the request for a later completion. The status argument will be given to the completion functions. MPI_WAIT is used for complete the call to the previous functions (identified by the first argument) and will wait until the functions are effectively completed. Third version - Sendrecv. The next version use a send-receive function: it is equivalent to call a send and a receive function in parallel. Only the while loop differ: while(k++<MAX_ITERATION) { //The transfers are simultaneous MPI_Sendrecv(A+N,N,MPI_INT,left,MSG_DATA,A+(step+1)*N,N,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD,&status); MPI_Sendrecv(A+(step)*N,N,MPI_INT,right,MSG_DATA,A,N,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,&status); for (i=1;i<step-1;i++) { *(A+i*N)=*(A+i*N+N-2); *(A+i*N+N-1)=*(A+i*N+1); for (i=0;i<step;i++) for (j=0;j<N-2;j++) *(tmp+i*N+j)=f(*(A+(i+1)*N+j),*(A+(i+1)*N+j+2),*(A+i*N+j+1),*(A+(i+2)*N+j+1)); for (i=1;i<step+1;i++) for (j=1;j<N-1;j++) *(A+i*N+j)=*(tmp+(i-1)*N+j-1); The MPI_SENDRECV function need arguments which are essentially the same that are required by the MPI_SEND and MPI_RECV functions. Fourth version - Ring topology. This last version is radically different, in which that the topology used is a ring topology. A new matrix is calculated on the process 0 and then is sent to the process 1. After one iteration, this process send it to the process 2, which calculate the new matrix and send it again to the next process. The last process will return the matrix to the master and the cycle will continue until the number of iteration reach a defined constant (see figure below). With this topology, several different data can be computed in the same time. Although in this example the operation applied on the data are the same, the processes can carry out different kinds of operation. Only one matrix will be sent in the ring. It is however possible (and it is the advantage of this structure) to send a second matrix just after. /* Cellular automata - Parallel version using a ring topology */ #include <stdio.h> #include <stdlib.h> #include <mpi.h> #define N 62 #define MAX_ITERATION N #define MSG_DATA 100 #define MSG_RESULT 101 void init_mat (int *A, int length); void writemat (int *A, int length); int f (int x1,int x2,int x3,int x4); int main (int argc, char **argv) { int* A=(int*)malloc((N*N+1)*sizeof(int)); int* B=(int*)malloc((N-2)*(N-2)*sizeof(int)); int myrank,size,left,right; MPI_Status status; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); MPI_Comm_size (MPI_COMM_WORLD, &size); int i,j,k=0; right=(myrank+1)%size; left=(myrank-1+size)%size; if (!myrank) init_mat(A,N); else MPI_Recv (A,N*N+1,MPI_INT,left,MSG_DATA,MPI_COMM_WORLD,&status); while (*(A+N*N)<MAX_ITERATION) { for (i=0;i<N-2;i++) for (j=0;j<N-2;j++) *(B+i*N+j)=f(*(A+(i+1)*N+j),*(A+(i+1)*N+j+2),*(A+i*N+j+1),*(A+(i+2)*N+j+1)); for (i=1;i<N-1;i++) for (j=1;j<N-1;j++) *(A+i*N+j)=*(B+(i-1)*N+j-1); for (i=1;i<N-1;i++) { *(A+i)=*(A+(N-2)*N+i); *(A+(N-1)*N+i)=*(A+N+i); *(A+i*N)=*(A+i*N+N-2); *(A+i*N+N-1)=*(A+i*N+1); //The number of iteration is incremented (*(A+N*N))++; //The matrix is sent and another is receive MPI_Sendrecv_replace(A,N*N+1,MPI_INT,right,MSG_DATA,left,MSG_DATA,MPI_COMM_WORLD,&status); //When the number of iteration reach the maximum, the program stop if ((*(A+N*N))++==MAX_ITERATION) { MPI_Sendrecv_replace(A,N*N+1,MPI_INT,right,MSG_DATA,left,MSG_DATA,MPI_COMM_WORLD,&status); writemat(A,N); } else MPI_Send (A,N*N+1,MPI_INT,right,MSG_DATA,MPI_COMM_WORLD); MPI_Finalize (); return 0; The number of iterations is stored with the matrix, in an additional element. It will serve to determine when to stop the loop. When one process will reach the maximum number of iterations, the matrix will then be transferred on all the other processes. It is indeed necessary for stopping these properly because else, they will continue their loop and never stop. The MPI_SENDRECV_REPLACE function is similar to the MPI_SENDRECV function, though it use the same buffer for sending and receiving the data. Differentiation. This program will calculate the numerical value of the derivate of a functions in multiple points by using the finite elements method. The equation is: formula_2 However, it is numerically difficult to divide by 0 and h must not be chosen arbitrary (see figure below). The optimal value of h is unknown and thus, the algorithm will decrease a started value of h until that the precision began to decrease (the difference between two derivate calculated with different h must decrease). In C programming, the sequential version is: /* Derivate - Sequential version */ #include <stdio.h> #include <math.h> #define H 1 //first h #define DEC 1.4 //decrease #define N 500 double f (double x); int main (int argc, char **argv) { double x,deriv,diffnew,diffold,h; double result; int i; for (i=0,x=i;i<N;x=++i) { h=H; deriv=(f(x+h)-f(x-h))/(2*h); diffnew=100; diffold=2*diffnew; while (fabs(diffnew)<fabs(diffold)) { h/=DEC; result=deriv; diffold=diffnew; deriv=(f(x+h)-f(x-h))/(2*h); diffnew=deriv-result; printf ("%lf: %.15lf\n",x,result); return 0; double f (double x) { return x*x*x+x*x; First version - Farming topology. Since the number of loop is variable, the time of execution cannot be predicted. This program send a derivate to calculate to each processes and when one have finish (not necessarily the first), he resend immediately data to this one. These data and the result are gathered into two arrays (deriv[] and result[]). /* Derivate - Parallel version using farming topology */ #include <stdio.h> #include <mpi.h> #include <math.h> #define H 1 //first h #define DEC 1.4 //decrease (1.4) #define N 500 #define MSG_DATA 100 #define MSG_RESULT 101 double f (double x); void init_deriv(double *deriv, double x); void master (void); void slave (void); int main (int argc, char **argv) { int myrank; MPI_Init (&argc, &argv); MPI_Comm_rank (MPI_COMM_WORLD, &myrank); if (!myrank) master (); else slave (); MPI_Finalize (); return 0; void init_deriv(double *deriv, double x) { deriv[0]=x; deriv[4]=H; deriv[1]=(f(deriv[0]+deriv[4])-f(deriv[0]-deriv[4]))/(2*deriv[4]); deriv[2]=100; deriv[3]=2*deriv[2]; void master(void) { double deriv[5],result[2]; //x,deriv,diffnew,diffold,h int i; int size; MPI_Status status; MPI_Comm_size(MPI_COMM_WORLD,&size); //Sending data to all processes for (i=1;i<size;i++) { init_deriv(deriv,1); MPI_Send(deriv,5,MPI_DOUBLE,i,MSG_DATA,MPI_COMM_WORLD); //When a result is received, another task is sent for (;i<N;++i) { init_deriv(deriv,1); MPI_Recv(result,2,MPI_DOUBLE,MPI_ANY_SOURCE,MSG_RESULT,MPI_COMM_WORLD,&status); MPI_Send(deriv,5,MPI_DOUBLE,status.MPI_SOURCE,MSG_DATA,MPI_COMM_WORLD); printf ("%lf: %.15lf\n",result[0],result[1]); deriv[4]=10*H; //The current task are completed for (i=1;i<size;i++) { MPI_Recv(result,2,MPI_DOUBLE,MPI_ANY_SOURCE,MSG_RESULT,MPI_COMM_WORLD,&status); MPI_Send(deriv,5,MPI_DOUBLE,status.MPI_SOURCE,MSG_DATA,MPI_COMM_WORLD); printf ("%lf: %.15lf\n",result[0],result[1]); void slave(void) { double deriv[5],result[2]; //x,deriv,diffnew,diffold,h MPI_Status status; MPI_Recv(deriv,5,MPI_DOUBLE,0,MSG_DATA,MPI_COMM_WORLD,&status); while (deriv[4]<5*H) { while (fabs(deriv[2])<fabs(deriv[3])) { deriv[4]/=DEC; result[1]=deriv[1]; deriv[3]=deriv[2]; deriv[1]=(f(deriv[0]+deriv[4])-f(deriv[0]-deriv[4]))/(2*deriv[4]); deriv[2]=deriv[1]-result[1]; result[0]=deriv[0]; MPI_Send (result,2,MPI_DOUBLE,0,MSG_RESULT,MPI_COMM_WORLD); MPI_Recv (deriv,5,MPI_DOUBLE,0,MSG_DATA,MPI_COMM_WORLD,&status); Second version - Completion of send and receive. The second topology illustrated looks like to a ring topology and introduce a new routine: MPI_REQUEST_FREE. The master will always send data to the process 1 and receive the result from any others processes (see figure below). Since the code of the slave is similar to that of the cellular automata (in the version using a ring topology), only the master function will be described. For avoiding deadlock, only non-blocking send will be used (the non-blocking receive is used here for improving performance). void master(void) { double deriv[5],result[2]; //x,deriv,diffnew,diffold,h int i; int size; MPI_Status status; MPI_Request request[N],req; MPI_Comm_size(MPI_COMM_WORLD,&size); //The master fill the ring by sending enough data for (i=1;i<size;i++) { init_deriv(deriv,i); MPI_Isend(deriv,5,MPI_DOUBLE,1,MSG_DATA,MPI_COMM_WORLD,request+i); //When a result is received, another data is sent in the ring for (;i<N;++i) { MPI_Irecv(result,2,MPI_DOUBLE,MPI_ANY_SOURCE,MSG_RESULT,MPI_COMM_WORLD,&req); init_deriv(deriv,i); MPI_Wait (&req,&status); MPI_Request_free (request+(int)result[0]); MPI_Isend(deriv,5,MPI_DOUBLE,1,MSG_DATA,MPI_COMM_WORLD,request+i); printf ("%lf: %.15lf\n",result[0],result[1]); //The current task are completed for (i=1;i<size;i++) { MPI_Recv(result,2,MPI_DOUBLE,MPI_ANY_SOURCE,MSG_RESULT,MPI_COMM_WORLD,&status); MPI_Request_free (request+(int)result[0]); printf ("%lf: %.15lf\n",result[0],result[1]); When the master finish to send enough data (for all processes), it execute a new loop. It receive a result and initialize a new data simultaneously and next, it complete the send of the data that lead to the result that it just receive and he resend in the ring a new data. Actually, if the master receive the result of a data, this means that the send of this data is completed and there is no need to complete the send. The MPI_REQUEST_FREE function allow to free a buffered request without checking when this request is logically completed. Communicators and groups. The collective communications (like MPI_BCAST, MPI_SCATTER and MPI_GATHER) send data on the processes that belong to a same group. MPI provide functions for managing groups and communicators. This allows to use collective communications on specified processes and thus to divide a network into groups which can execute different task. For example, different operations can occurred on a matrix (trace, transpose, inversion, diagonalizing). For each operations, a group will be defined and each processes will communicate with the other processes of its groups by using collective communication without disturbing other groups. A communicator is a object which specifies a communication domain. It is associated to a group. A group is created from existing groups and the initial group is the group of the communicator MPI_COMM_WORLD which contains all processes. First version - Creation of communicator from a group. The first method for creating new communicators is to create groups from this first group and then to create the communicators of these groups. /* Example of use of group */ #include <stdio.h> #include <mpi.h> int main (int argc, char *argv[]) { int rank[50],size,i,myrank; char data[10]=""; MPI_Group group,newgroup; MPI_Comm newcomm; MPI_Init (&argc,&argv); //group of MPI_COMM_WORLD which contains all the processes MPI_Comm_group (MPI_COMM_WORLD,&group); MPI_Group_size (group,&size); //Creation of the communicator containing even-ranked processes for (i=0;i<size/2;i++) rank[i]=2*i; if (size%2) rank[size/2]=size-1; MPI_Group_incl (group,(size+1)/2,rank,&newgroup); MPI_Comm_create (MPI_COMM_WORLD,newgroup,&newcomm); //Only the processes belonging to the group of newcomm will participate to the broadcast on this communicator MPI_Comm_rank (MPI_COMM_WORLD,&myrank); if (!(myrank%2)) MPI_Bcast (data,10,MPI_INT,0,newcomm); MPI_Group_free (&group); MPI_Finalize (); return 0; In this program, data are broadcast only on the even-ranked processes. This is achieved by creating a communicator which will contain the group of the even-ranked processes. First, the initial group of MPI_COMM_WORLD is given by the MPI_COMM_GROUP routine. The new created group contains the formula_3 processes that have a even rank in the initial group. The MPI_GROUP_INCL function required an array of the ranks of the processes of the first group that will belong to the new group. Then, MPI_COMM_CREATE create the communicator of the new group and if the process have a odd rank, it participates to the broadcast. The group is free by MPI_GROUP_FREE. The MPI_GROUP_SIZE and the MPI_COMM_RANK functions are similar to MPI_COMM_SIZE and MPI_GROUP_RANK. These last are just shortcut: However, if the process that call MPI_GROUP_RANK don't belong to the group specified in argument to the function, the value return in rank will be MPI_UNDEFINED whereas a call to MPI_COMM_RANK will not work and will stop the program. Second version - Creation of communicator from a communicator. One communicator can also be creating without using group, directly by splitting a existing communicator. int main (int argc, char *argv[]) { int color,i,myrank; char data[10]=""; MPI_Comm newcomm; MPI_Init (&argc,&argv); MPI_Comm_rank (MPI_COMM_WORLD,&myrank); //Creation of the communicator containing even-ranked processes if (!(myrank%2)) color=0; else color=1; MPI_Comm_split (MPI_COMM_WORLD,color,1,&newcomm); //Only the processes having even rank will participate to the broadcast on this communicator if (!(myrank%2)) MPI_Bcast (data,10,MPI_INT,0,newcomm); MPI_Finalize (); return 0; All the processes will be classified in a new communicator, depending of his color. Namely, if two processes have a color equal to 1 and one process have a color equal to 2, two communicators will be created, one for each groups. The third argument required by MPI_COMM_SPLIT is used for ordering the processes in the new communicator (this will change the rank of the new processes). Here, the same value is given for all processes. Divers. Environmental management. Finally, environmental management functions exist for getting the name of the node on which a process run or for measuring the time taken by a part of a program (for example). /* Example of use of environmental function */ #include <stdio.h> #include <mpi.h> int main (int argc, char *argv[]) { double starttime,endtime; int namelen; char processor_name[MPI_MAX_PROCESSOR_NAME]; MPI_Init(&argc,&argv); MPI_Get_processor_name(processor_name,&namelen); printf ("Process %s\n", processor_name); starttime = MPI_Wtime(); //Here some computation or communication endtime = MPI_Wtime(); printf ("Time: %lf\n",endtime-starttime); MPI_Finalize (); return 0; Other possibilities. There is many other functions that are not mentioned: there is different kinds of point-to-point communication functions; MPI allow user to define datatype by a lot of different functions; there is also other collective communication and reduction functions; and, more functions for using communicators and groups. MPI defines many useful constant, among those codice_29, codice_16, codice_48, ... MPI can also be used in an advanced way for managing process topologies. Namely, the MPI implementation can exploit the specificity of a physical network (for heterogeneous network) by privileging for example the transfer of message on the fastest connection. Prototype of basic functions. For more information on these MPI functions, report to the man page: int MPI_Init(int *argc, char ***argv); int MPI_Finalize(void); int MPI_Comm_rank(MPI_Comm comm, int *rank); int MPI_Comm_size(MPI_Comm comm, int *size); int MPI_Send(void* buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm); int MPI_Recv(void* buf, int count, MPI_Datatype datatype, int source, int tag, MPI_Comm comm, MPI_Status *status); int MPI_Get_count(MPI_Status *status, MPI_Datatype datatype, int *count); int MPI_Type_extent(MPI_Datatype datatype, MPI_Aint *extent); int MPI_Type_struct(int count, int *array_of_blocklengths, MPI_Aint *array_of_displacements, MPI_Datatype *array_of_types, MPI_Datatype *newtype); int MPI_Bcast(void* buffer, int count, MPI_Datatype datatype, int root, MPI_Comm comm); int MPI_Scatter(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvcount, int root, MPI_Comm comm); int MPI_Gather(void* sendbuf, int sendcount, MPI_Datatype sendype, void* recvbuf, int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm); int MPI_ISend(void* buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm, MPI_Request *request); int MPI_Irecv(void* buf, int count, MPI_Datatype datatype, int source, int tag, MPI_Comm comm, MPI_Request *request); int MPI_Sendrecv(void* sendbuf, int sendcount, MPI_Datatype datatype, int dest, int sendtag, void* recvbuf, int recvcount, MPI_Datatype recvtype, int source, int recvtag, MPI_Comm comm, MPI_Status *status); int MPI_Sendrecv_replace(void* buf, int count, MPI_Datatype datatype, int dest, int sendtag, int source, int recvtag, MPI_Comm comm, MPI_Status *status); int MPI_Wait(MPI_Request *request, MPI_Status *status); int MPI_Request_free(MPI_Request *request); int MPI_Group_rank(MPI_Group group, int *rank); int MPI_Group_size(MPI_Group group, int *size); int MPI_Comm_group(MPI_Comm comm, MPI_Group *group); int MPI_Group_free(MPI_Group *group); int MPI_Group_incl(MPI_Group *group, int n, int *ranks, MPI_Group *newgroup); int MPI_Comm_create(MPI_Comm comm, MPI_Group group, MPI_Comm *newgroup); int MPI_Comm_split(MPI_Comm comm, int color, int key, MPI_Comm *newcomm); int MPI_Wtime(void); int MPI_Get_processor_name(char *name, int *resultlen); "As usual in the C programming language, the "address of an array" is really the address of the first element of the array."

The Design and Organization of Data Centers/Introduction. Introduction to the topic. The design and organization of your company's data center has a direct impact on its day-to-day operations. The following are just some of the considerations involved: The need to deliberately design and organize. To maximize uptime, minimize length of outages, and optimize capacity subject to resource constraints, one should deliberately design and organize the data center. The following considerations merely highlight the importance of careful planning:

The Design and Organization of Data Centers/Planning. Design requirements. Initial equipment list Initial schedule Expected growth Growth schedule Budget Level of flexibility Impressing visitors

The Design and Organization of Data Centers/Location. Considerations. Cost. Shop around to compare prices. Many co-location centers give initially inflated prices. Safety. Safety from water damage. HVAC can fail in such a way that water comes out. Look out for pipes, vents, and ducts above your equipment. Air conditioners can freeze up and then thaw, water heaters can fail, ventilation ducts can pack with snow, toilets can overflow, etc. The building may be in a flood zone - does the insurance cover the damage? How long will it take to file the claim? Document who you must contact before the disaster happens. Natural and manmade hazards. Natural hazards. etc.

The Design and Organization of Data Centers/Redundancy. Everything will eventually fail. Redundancy allows you to minimize the damage of a system failure. Failure characteristics. Planned vs. unplanned Total vs. partial Frequency of failure Length of partial failure or outage Types of redundancy. Structure. Ladder Mesh N+1 Implementation. Active/active Active/passive Human Factors. Notification Unattended problem resolution Documentation and problem clarity Allowance for no-impact maintenance

The Design and Organization of Data Centers/Electrical. Uninteruptable Power Supplies. Absolutely necessary Central UPS. All equipment stays up for same length of time. Rack-mounted UPS. Put batteries where they are needed most. Easy redundancy with dual power supply computers. Server-mounted battery. Google servers are connected directly to the AC feed with no UPS in the middle. Instead, each server has its own 12 VDC battery, which is used to power the server during power outages. Brick UPS. Good for smaller installations. Easy redundancy with dual power supply computers. Sizing. Loads that cannot tolerate any outage shall be placed on UPS power. Critical systems, such as the air conditioning cannot tolerate a brief outage, so they should be supported from generator power. Battery run time for UPS loads are dependent upon the budget and level of reliability required. With a well designed backup generation system, UPS runtime may be minimized since the gensets will be online in 8 to 20 seconds. Power Interruption. Plan for unattended shutdown and restart whenever possible. Consider remote alert of power interruption. Make sure the KVM is also on UPS. Make sure you have emergency lights and flashlights for working in the dark. Estimating remaining run time Restart of UPS after full drain Redundant UPS systems. Rack-mounted - side to side redundancy. Central UPS - need two of them with separate breaker boxes/PDUs and color coded system. Generators. Determine your local outage characteristics for your power supplier. Do they tend to be infrequent, but long? Common, but short? On-site vs delivery contract On site minimizes need for large UPSes Environmental issues and permit requirements for fuel storage Layout and Redundancy. Look for computers with dual power supplies, or, less preferably, make sure you have redundant boxes per function. This allows for rearranging power cables and moving a box from one area to another without turning it off. Maintain side-to-side redundancy by placing power strips on separate breakers or UPSes. Remote Power Control. Remote power on and off Resetting stuck machines and routers Power on sequencing Electrical Grounding/Earthing. All metal server or network racks and cabinets, overhead raceways and metallic conduit must be properly grounded to each other and to ground.

The Design and Organization of Data Centers/Air Conditioning. Sizing. Air conditioners are rated by tonnage. One ton equals 12,000 BTU per hour. Equipment heat output is rated in BTUs. Conversion rates and guides can be found in the appendix. Use this to size the cooling load! Northern Air Conditioning Orange County NY Redundancy issues. Your air conditioner will fail. It is only a matter of when and whether you have one to back it up. Emergency Fan ventilation. Can you ventilate into the building or the outside? What is the outside summer temperature? Multiple air conditioners. Spare Over-sized Mov-n-cools Alarm fail over Thermostatic fail over Differential temperature settings Layout your air conditioners to minimize temperature variation across the room. Humidity Control. Found in larger systems Eliminates static problems Requires addition of plumbing Hot Aisles and Cold Aisles. Data centers are often separated into hot aisles and cold aisles. The back of the racks or cabinets face the hot aisle, because the hot air is blown in that direction. The fronts of 2 rows of cabinets face each other, and cold air is blown into this aisle to be forced through the front of the servers and out the back into the hot aisles. Return air ducts are above the hot aisles, while cold air is blown up from underneath the floor into the cold aisle and sometimes into the front of the server cabinets.

The Design and Organization of Data Centers/Fire Protection. Fire alarms systems are designed to detect and notify building occupants of a possible fire condition, so that proper reactive steps can be taken. Some examples of fire alarm equipment include the following: Sprinkler systems. Water and computers don't mix. A damaged sprinkler head will spray water regardless of a fire, and smoke detectors can be set off by dust. Avoid sprinkler systems that hold water, instead use a pre-action sprinkler system, preferably a double-interlocked pre-action system. With a double-interlocking pre-action valve, water is prevented from entering the sprinkler piping until two different kinds of heat/smoke detecting devices trigger the valve to open. The typical devices used are pneumatic actuation by a sprinkler head activating and releasing pressurized air stored in the piping and an electric actuation from heat or smoke detectors. Gas Suppression. Halon. Not used any more Energen. More expensive, but free refills, non-toxic May require separate under-floor nozzles, and ceiling tiles restrained with clips. Fire Extinguishers. Special fire extinguishers Low residue Expensive Power and Air conditioning issues. Emergency shut off for power and air conditioning Very Important stuff.

The Design and Organization of Data Centers/Security Systems. Reasoning. More difficult entry Selective access Entry evident Traceable access Design. Determine who should have access to what How many layers of access will there be Consider using locking cabinets but not using computer locks Consider locks on interior doors and fire cabinets. Physical keys vs. card pass system Key Management. Centralized key box for computer keys Room keys may need to be given to CEO, landlord, and fire department for placement in Knox box. Pass Card Systems. For card pass system, make sure entries are logged. Avoid double-door magnet systems for passcard entry. Proximity or RFID cards are harder to forge and easier to use Security Systems. Use a combination of motion detectors and door sensors. This does several things: Security systems are cheap compared to your other expenses. Splurge on the goodies, such as alarm pads with full English displays. Also consider having security system monitor the power, temperature, and fire with remote callout alerts. Visitors and Contractors. Use sign-in book for contractors and record name, company, identification number, date of entry, phone number, and purpose of visit so that problems can be traced. I question the usefulness of having all visitors in a tour sign in. Make sure all visitors are escorted by qualified personnel.

The Design and Organization of Data Centers/Layout Considerations. Entrance Facility. Consider where network and power comes into the building and where it will enter the data center, and how this will affect location of main edge routers, where cross connections will take place, placement of power transformers switches and UPS units. You may have multiple electrical entrance facilities for redundancy. Space for wiring. Determine use of raised floor and/or overhead cable trays. Some rack-to-rack cable organization will be necessary. Rack Layout. It is crucial to lay out your racks, shelving, and stand-alone systems with accuracy of a few inches when considering location over raised floor access ports. You should have a minimum of three feet between rack front and back to allow for opening of doors. A 6' rack spacing interval is recommended as floor tiles come in 2'x2'. The location of the wheels and/or feet at the bottom of a rack are critical to being able to lift floor panels. Space for other necessities. You may want to have space for a desk with monitor, if you don't have a formal office or NOC on the premise. You will want to have storage units for copious documentation and spare parts, unless you just use an empty rack, and possibly a place to drop old hard drives for secure disposal. Phones and switches. Place light, power, and fire switches in an easy to reach place. If you have two entrances, have light switches at both entrances especially if main lighting is normally kept off. Make sure phone is in easy reach of fire suppression cut off switch, NOT the other way around. Mechanicals. Consider putting "non-computer" assets in separate rooms. You can contain leaks easier, as well as keep service technicians away from servers, increasing security, and reducing the need for supervision.

The Design and Organization of Data Centers/Contractors. Finding possible contractors. Landlord may do some physical work. Remember to deal with lease issues. Look for contractors experienced in data center construction. Get references, check them using a reference call checklist Getting quality quotes. Get a minimum of three quotes.Some will completely ignore what you say is important. Write up quote specifications in detail. This allows you to send the same information to multiple vendors, and compare the quotes fairly, as well as hold vendors to what you want done in the future. Suggested quote requirements and specifications: cost analysis and comparison between quotes. best solution. Common problems. Watch out for bait and switch. Find out if the contractor or project manager that comes in and does the quoting will be the one actually working on the job. For town permits, use one and only one point of contact, as this can get quite confusing and is critical in the final stages. Always get quotes for jobs over a certain level, say, $10,000. This can save money and keep your favorite contractors quotes low. Coordinate between your contractors. When installing a drop-ceiling in combination with a gas fire suppression system, make sure that the tile retaining clips are put into place AFTER any wiring has been done in the ceiling, as security and phone wires may be run up there. Contractors won't do all your work. Consider having an assistant to do gopher and grunt work such as building furniture. Remember, time used to get the quote adds on to the final completion date.

The Design and Organization of Data Centers/Racks and Cabinets. Rack-mount systems in general. The quality and layout of your racks and cabinets can save you hours in frustration, keep your equipment organized, and reduce the length of downtime by speeding repairs. When comparing racks and cabinets, examine the items in person. Ask to see some in a data center near you. Buyer beware. Vertical columns with holes for mounting equipment Over the years several different rack mounting scemes have come out, varying from 16" to 49". These widths are measured horizontally from centre of hole to center of hole. The 2 surviving standards are the 19" and the 23". The 23" standard is used by the telecommunications industry and virtually everyone else uses the 19" standard. Equipment intended for rackmount is sized vertically by "U" units, which equals 1.75 inches. Compliant hardware is built in multiples of this 1.75" unit. There were tape measures made that were calibrated in rack units, they are difficult to find. Note that the holes are unevenly spaced. Narrow gap, wide gap, wide gap and back to narrow. Your equipment should always line up at the top and bottom with narrow gaps. Doing otherwise will leave you with a sloppy unprofessional installation. Recently, 1-U high computer servers have become available. Open racks vs. closed cabinets. Open rack systems are more useful for short equipment with many wires, like hubs, switches, and routers. Closed cabinets are more useful for deep things like servers, and when you want to lock down physical access. Mounting column style. Round threaded. 10-32 or 10-24 Round unthreaded. Requires clip-nuts Square punched. Square-punched is often referred to as Compaq-style. Square-punched requires the use of clip or cage nuts and can be inconvenient unless sliding rails are designed specifically for that style. When using square-hole racks, quality nuts are very important. There are at least two styles: clip nuts have a thin metal clip that clips over the edge of the column and are easily dislodged; cage nuts clips into the square. Mounting methods. Front bracket only. Used for lighter equipment, such as network devices and KVMs. Four post. Used for larger equipment. Shelf. Great for monitors, keyboards, and oddly shaped equipment. Sliding rail. Mounts on front and rear rails. Sliding rails are mounted individually to the side columns and then the computer is slid into place. Some rail mounts will interfere with center-side columns and the center columns must be removed. Use sliding rails for mounting computers, whenever possible, as it makes mounting the hardware easier and allows you to slide the machine out for maintenance. When using sliding rails, ALWAYS lock the computer in place with front-mounted screws or risk catastrophic tipping. Whenever possible, when ordering equipment, specify rail mount. Rack Features To Look For. Always make sure shelves are available for any rack system you buy, and buy a few extra; they come in handy. Front-column to mid- and rear-column spacing should be adjustable and is critical to easing the mounting of computers. Always order deep cabinets, as many servers are quite deep, and you will need space for routing the wires. Cabinets should be about 32-36" deep, on the external dimension. Some racks are connectible with a kit that removes the sides and ties the cabinets together to make an extra wide cabinet making it easier to run wires between sets of 19" racks. Fit and finish count. Look for dangerous undebarred edges. Determine if you can specify keyed-alike doors Installation Suggestions. Whenever equipment uses the rear or mid-rails, try to keep the same type of equipment in the same rack. When mounting many odd-sized units in one rack, consider using shelves instead of rail-mounts. Always mount equipment in such a way that the side of the box that needs access to the cables is on the same side. This means most hubs and switches and some routers should actually be mounted on the rear rail. This means you don't have to pass cables from front to back of the cabinet. Use large-head Phillips-head screws, called truss head in catalogs. Better yet are rack specific screws. These are truss head screws that have a unthreaded portion to help align the screw. Do not use thread-cutting screws with little teeth on the tip of the screw, as sold by some network equipment companies. You can cross thread these and ruin your threads.

The Design and Organization of Data Centers/Wiring. Keeping your wiring organized is a never-ending struggle. Make sure to make it as easy as possible. fire safety considerations. types of cable: Under Floor Organization. Place your major power lines in properly grounded metal conduit. Put all under-floor fiber connections in plenum-certified conduit, such as the orange crinkle tube. If using electrical whips underneath floors, make sure the socket boxes are physically restrained in place and marked with the location on both ends. Run all conduits and wires square to the floor panels to allow for easier under-floor organization. When placing electrical power whips underneath the floor, take the time to make sure they are cut very close to length, as extra loops of this cable can take up a lot of space under the floor. Physically separate power from network cabling as much as possible. You may have only power conduits and cables under the raised floor, and network cabling in overhead cable trays, or vice-versa. Rack to Rack Connections. Consider whether you want to use network switches and hubs in each rack and connect those to a central location, or use patch panels that go from rack to rack. Use patch panels and other techniques to minimize how often you have to go into the floor. You should not need to lift floor panels to install a new computer. Keyboard Video Mouse Switches. Consider using your KVM connections sparingly, using only one or two per rack and moving them when necessary for maintenance. Buy a high-quality KVM, as quality counts, and go with an on-screen menu that allows you to label the computers. Make sure your KVM allows for keyboard switching. Compare against serial terminal servers if you have Unix boxes. Use true KVM cables. Cables that you zip-tie together are harder to remove later. Also, the video connection that uses screws is shorter than the PS/2 connections, to reduce cable pull out. Cable Management. Many products for rack cable management. Velcro zipties are reusable. Use Ethernet cables of many color and lengths. Consider color coding by length. Use only booted cables as they won't get caught up when being moved around. Consider putting a unique serial number on both ends of every single cable going into your data center. Use the shortest power cables possible. Put serial numbers on the power cables and consider using black and beige colored cables to show side-to-side redundancy. Pre-plan location of power outlets on rack systems. Planning for Expansion. Plan for extra analog phone jacks during construction, as they are often used for modems on equipment. Consider making them 56K leased-line capable.

The Design and Organization of Data Centers/Outfitting. Furniture. Put EVERYTHING on wheels

The Design and Organization of Data Centers/Documentation. Labeling. Neatness begets neatness. Use a label maker. It means your labels look neat, uniform, and are easy to read. Label front and back of machine with name, IP address, & MAC Address. This means you are less likely to pull the wrong cable or shut down the wrong machine. Label multiple NICS on a single machine. Document VLANs on switches to allow installation without a network engineer. Organizing your documentation. Keep documentation where it is needed. Make sure it is easy to update. Self adhesive vinyl pockets - great for walls and cabinets Folder pockets - great for three ring binders Consider a wiki or FAQ-o-matic, but have paper backups printed regularly. Understanding of a problem leads to quicker resolution. Documentation can be part of that.

The Design and Organization of Data Centers/Appendix A. Air conditioning. Common Values Chiller calcs. Assuming that all wattage consumed will end up as dissipated heat (servers do very little mechanical work or yield very little light); Wattage times 3.41 = BTU/hr Example: Server draws 10 amps at 120vac 10 amps X 120 vac = 1200 voltamps (aprox 1200 watts) 1200 VA X 3.41 = 4092 BTU/hr

The Design and Organization of Data Centers/Appendix B. Towards Operational Excellence The Data Center Journal Email list: [email protected]

Canadian Tort Law/Trespass to person. Some of the main intentional torts against the person are: Assault. Assault is intentionally causing the victim to believe that he or she will be imminently, physically contacted against his or her will. No contact actually has to occur; swinging a clenched fist at a victim is assault, even if the fist misses the victim, as long as the victim believed it would make contact. Physical harm need not occur; the harm is in the apprehension. The apprehended contact can come either from a gesture of the defendant, or by the defendant intentionally causing an object to threaten imminent contact. Pointing a pistol in the direction of a defendant and pulling the trigger is assault, even if it was not loaded. The belief of imminent contact must be reasonable. If the defendant showed the plaintiff that the gun was not loaded, then the plaintiff cannot sue for assault if the defendant then points the gun at him. A threat of force, such as "I am going to shoot you", can be an assault, if the threat is imminent. "I am going to shoot you in four years" is not an assault. A conditional threat of force can be an assault, such as an armed mugging ("Give me your wallet or I will shoot you"). On the other hand, a conditional threat of force that makes it clear that force would not actually be used is not assault. For instance, a threat such as "I would punch you, if the police weren't standing right there", is not an assault. Although it seems to be a threat of violence, it is implied that violence would not actually be carried out. One of the most common defences to assault is consent. The contact must be unwanted. (One might say, then, that lack of consent is an element of assault, rather than consent is a defence.) If someone were to say, "point the gun at me", then one cannot subsequently sue for assault. Consent can be express (specifically written or spoken), or it can be implied (by actions or words that lead to the logical conclusion that contact is wanted). For instance, if one joins a hockey game, one cannot normally sue for assault after receiving a body-check. Implied consent extends only to reasonable apprehensions of contact. Joining in a hockey game does not give all of the other players a license to commit any act of violence that they think of. Another defence to assault is self-defence. One is allowed to threaten an imminent contact against somebody else to prevent an assault that they reasonably believed was going to happen to them. The force used in self-defence must be proportional to the threat; however, judges often give some leeway to people who use violence in self-defence. The use of force must be the only option; if the defendant could have avoided the threatened assault in another way, such as running away, then the use of force in self-defence is not justified. Battery. Battery is an unwanted physical contact. Unlike assault, where an apprehended threat is necessary while actual contact is not, battery requires actual physical contact and does not require imminent threat. For instance, if someone is kicked while asleep, the victim never apprehended the contact before it happened. Therefore, the victim was battered but not assaulted. In practice, of course, assault and battery often happen in the same incident. Consent is a major defence to battery. When using this defence, the defendant must show that the consent was "informed", i.e., the plaintiff knew of the nature and consequences of consenting. This often arises in medical malpractice cases. If the patient agrees to heart surgery, but the surgeon performs other types of surgery not discussed with the patient while the patient is under anaesthetic, then that is battery. In medical malpractice cases, the distinction between battery and negligence can get quite blurry. If the surgeon does not tell the patient all of the possible major side-effects of the surgery, then does it constitute battery, as the patient did not give informed consent? Judges have tended to classify most cases of medical malpractice as negligence, reserving battery for the most clear cases of lack of consent. Consent that is coerced or incorrectly obtained through an unlawful use of power or influence is "vitiated", meaning that it is not really consent. For instance, a doctor using his ability to prescribe drugs to coerce a patient into consenting to battery vitiates the consent. "Norberg" v. "Wynrib", [1992 2 S.C.R. 226.] False Imprisonment. False imprisonment is the intentional, unlawful confinement of a person to a space. The person's imprisonment need not last a long time. Nor does the confinement have to be physical; it could be applied by psychological pressure (e.g., "If you leave now, I will tell everyone that you came here to buy drugs...") False imprisonment is, not surprisingly, used mostly against police officers for arresting someone unlawfully. The Criminal Code gives police officers some protection against lawsuits for false imprisonment. Back to Canadian Law

Canadian Tort Law/Negligence. Introduction. Perhaps no development in common law has had quite as great an impact as the case of"Donoghue " v. "Stevenson", [1932 A.C. 562]. In this, a woman from Glasgow became ill after drinking an opaque bottle of ginger beer. She claimed that the remains of a decomposed snail were found in the bottle. She sued the bottling company. Before this case, the idea that a plaintiff could sue someone with whom one had no contract and who had not directly committed the harm to the victim was not recognized in common law. However, in this decision of the House of Lords, Lord Atkin set out the principle, known as the "Neighbour Principle" or the "Duty of Care": Duty of care. There can be no legal accountability of a person's actions without a duty being imposed upon them. As first established in "Donoghue v. Stevenson", an obligation can be imposed upon people whose actions can foreseeably harm others. Established Duties. Reliance. Reasonable reliance, refers to when individuals refer to the information provided by professionals for another purpose. In those cases, the fiduciary duty set for a professional is limited in that the information provided was not used for what was intended by the professional, even if it caused harm and was wrong. Standard of care. All negligent tort actions focus on the issue what the standard of care was and whether the defendant fell below that standard. The standard is judged in relation to the "reasonable person" and whether the defendant acted in the same manner as any rational person in society would. This standard is very ephemeral and does not provide a clear or objective criteria for judging. The standard changes depending on the assumed knowledge and experience of the defendant; for example, a professional will be held to a higher level than a normal person. Moreover the level of risk involved plays a major role in establishing the standard of care. The likelihood of harm resulting from the actions as well as the level of forseeability of harm are taken into account. In "Bolton v. Stone" H.L. [1951] the defendant was playing cricket and hit to ball out into the stands where it hit the plaintiff. The judge ruled that since the ball had only been hit that far about six times in 30 years there was very little likelihood of it happening, meaning the risk was very low, thus could not attribute negligence. Causation. As with each other element of a tort, causation must be shown for a successful action. The Supreme Court in "Snell v. Farrell" (1990) described causation as "an expression of the relationship that must be found to exist between the tortious act of the wrongdoer and the injury to the victim in order to justify compensation of the latter out of the pocket of the former." Remoteness - Limits to Liability. The remoteness factor - sometimes called proximate cause - in a tort action is said to be the most confusing and inconsistent of all. The case law has a very spotty history and is known for not always being consistently applied. Type of injury. Physical Harm Emotional Harm Psychiatric Harm Economic Loss - Pure Economic Loss - Consequential Economic Loss - Relational Economic Loss

Swedish/Lesson 4. Family Values. Immediate Family. Parents:. Collectively, parents are known as "föräldrar". Just like in English, the Swedish language has several words for "mother" and "father", ranging from formal to casual. Starting with the words for "mother", we have: The most common words for "father" are: Note that when "addressing" your folks with the casual terms, you use the definite forms "farsan" and "morsan". Siblings. The words for "syskon" (siblings) are for "brother": and for "sister": The same goes here. You address them "brorsan" and "syrran". The word "syskon" itself is more commonly used (for people) in Swedish than the English word "siblings". You would always translate "My brothers and sisters" with "Mina syskon", never with "Mina bröder och systrar", unless possibly if you want to make a special point about the differenses between them. Children. Children in general are referred to as "barn", in both singular and plural. A male child is called A female child is "Grandfamily". Maternal Grandparents. Collectively, your maternal grandparents are "morföräldrar" Paternal Grandparents. Collectively, your paternal grandparents are "farföräldrar". Great Grandparents. To build further, just add an s after every other generation Grandchildren. The formation of words for grandchildren follows the same pattern as for grandparents: To generically describe "grandchildren", use: A Little More Extended Family. † Sometimes also called "tant", which is also used as a common name for elder ladies. It's also possible to refer to an uncle with the less common word "onkel". ‡ "Farbror" is also used as a common name for old men.

Portuguese/Contents/Ser and estar. The easiest way to know Ser vs Estar Quickly and Easily is to look at these to tips: Ser= DOCTOR and Estar= PLACE Ser / DOCTOR Description (usually physical) / "Tu és alto" = You are tall Occupation (Job) / "Ele é um dentista" = He is a dentist Characteristics (Ser char. is only used when permanent/long) / "ele é uma boa pessoa"= he is a good person Time (To tell time) / São 16:30 = It's 4:30 Origin (To tell where someone or something is from, including purchases) / "Eu sou de Moçambique"= I am from Mozambique Relation (To express relationships, ex. she is my aunt) / "Nos somos amigos"= we are friends Estar / PLACE Position (To tell where you are) "Estou em casa"= I am at home Location (To tell where something is) "Está aí"= Its over there Action (Use action verbs here) "Estamos correndo"= We are running Condition (Tell the condition that something is in, more commonly) "Estás com fome?"= Are you hungry? Emotion (Tell something's or someone's emotions) "Eles estão tristes porque"...= They are sad because... Copula. One of the simplest constructions in any language is the ability to express a relation of equality between nouns or nouns and adjectives. This construction is often called "copula", the Latin word for 'link', 'bond'. For example, consider the following statements: These sentences link together the nouns (in these cases, 'John,' 'Mary' and 'Robert') with an adjective or noun (respectively, 'tall,' 'dentist' and 'happy'). In English, this is achieved by using the helper verb 'to be'. In Portuguese, as in Spanish, we have actually "two" verbs which serve that role. Let's examine them, each in turn: The first verb is "ser", which comes from the old Latin verb "esse", which meant 'to be'. It's conjugated (in the Present Indicative tense) as follows: eu sou tu és ele/ela/você é nós somos vos* sois eles/elas/vocês são The second verb is "estar", which comes from the old Latin verb "stare", which meant 'to stand'. It's conjugated (again, in the Present Indicative tense) as follows: eu estou tu estás ele/ela/você está nós estamos vós* estais eles/elas/vocês estão Using "ser" and "estar"- Usando Ser e Estar. Ok, now that we know the verbs, when do we know how to use them? What is the difference between "ser" and "estar"? The answer is actually quite simple, but it requires attention, especially for speakers of Spanish: the instances in which we use "ser" and which we use "estar" in Portuguese and Spanish are almost, but not always, the same. Remember when I said that the verb "ser" comes from "esse" and the verb "estar" comes from "stare"? Well, there are two words in English which also come from these two Latin verbs. From "esse" we have English "essence", and from "stare" we have English "status". So we use "ser" when we want to describe the essence of something, or how a thing is always; and we use "estar" when we want to describe something's status, or how a thing is at the moment. Let's see some examples, then, to fixate: In each of these cases, the speaker attributes to the subjects of the sentence characteristics that are intrinsic to them. People don't change names that often, or nationality. It is part of their identity. Also, things are generally only one color, with a few notable exceptions like chameleons or traffic lights. All these cases use the verb "ser". In these cases, the phrases describe temporary situations: beer can get warm, sick people get well, and books can be picked up and carried around. Therefore, these are cases where we use "estar". Notice that there are some cases where one could use "ser" or "estar" equally well; but in these cases, as expected, the meaning changes when we use one or the other case. Watch: Both sentences above translate to 'the young woman is pretty'; however, in the first case, we mean that the young woman is "naturally" pretty, like Anna Kournikova. In the second case, we mean that she is prettier than usual -- typically because she put on some nice clothes, got a haircut, or otherwise accessorized herself. She may or may not be pretty normally, but we want to call attention to the fact that she is prettier due to some temporary condition. Again, both cases translate to 'Tony is sick'. However, the first one explicitly says that Tony isn't usually sick, but is right now. The second one means that Tony is sick now, was in the past and will be in the future -- generally, this has connotations that Tony is "mentally" sick. The location of things. When we want to describe the location of things, naturally we use the copula. In this case, we use "ser" when something generally can't move around, and "estar" otherwise. Spanish speakers should be aware that this is different from Spanish, where "estar" is used everywhere. Some examples: In the first three examples, we have items which are expected to be able to be in a wide variety of places over time, so their location is not intrinsic to them: "estar" is used. In the last three examples, we have subjects which are generally immobile, and therefore have an intrinsic location; "ser" is the correct option then. Leny...

Bicycles/Maintenance and Repair/Suspension/Front suspension lubrication. It is best to go to the webpage of your fork's manufacturer and look there for specific information regarding your model and type of suspension fork. If you don't want too much hassle, rather take your bicycle to qualified bicycle mechanic.

How To Search/Stanford Encyclopedia of Philosophy. Stanford Encyclopedia of Philosophy Other Features. There is a directory available for those who just want to browse by title of encyclopedic article or by date of article creation.

Swedish/Teknik. Technology. Terminology. Disciplines. In general: -"nomi" is "-nomy" and -"logi" is "-logy". "Ch" is "k", "th" is "t" and "ph" is "f". "C" is "k" when pronounced as "k", otherwise "c". Stress is on last syllable unless stated otherwise with bold letters. Some tricky cases: "Swenglish". Since technology is a relatively newfangled thing in the big scheme of history, there are a lot of technology words that have been borrowed from english, especially in electronics and computer technology.

German/Level I/Freizeit/Test Answers. Instructions: You should be done with the test. Correct your test using these answers. To look back at the test, go here A. Grammar. Articles. 1. C 2. A 3. B 4. D 5. B 6. C 7. B 8. A 9. B 10. B Word Order. 1. b 2. c 3. a 4. d 5. a 6. c 7. c 8. b 9. d 10. c B. Translating. English to German. 1. A. Hallo. Wie heißt du? B. Ich heiße Thomas. Treibt ihr Sport? A. Ja, wir spielen Football. Spielst du Football? B. Nein, ich spiele Volleyball. C. Ich spiele auch Volleyball! Wann spielst du Volleyball? A. Ich spiele um 21.00 Uhr am Mittwoch Volleyball. C. Ich bin auch! 2. A. Macht Karl Sport? B. Ja, Karl spielt Tennis. A. Gut. Mark spielt auch Tennis. B. Wann spielt Mark Tennis? A. Um halb Fünf am Montag, Freitag, und Samstag. Aber er spielt auch Fußball am Samstag. B. Karl spielt Tennis am Sonntag, nicht Samstag. Grading: Each sentence is worth two points, except for 'Gut.' and 'Hallo.', which are considered part of the following sentences, and the second to last sentence in the first dialogue, which is worth three points. If a word is out of place, there is a word missing, or an extra word was added, take off ½ point. Remember not to take off more points than there are for that sentence. German to English. Grading: If a word is out of place, there is a word missing, or an extra word was added, take off ½ point. Remember not to take off more than two points per sentence or phrase. Numbers to German. Grading: If you mess up the months, days (dritten, for example), hours, or minutes, it is one point off. If you mess up anything else: capitalization, umlauts, Uhr, vor/nach, word order, or adding any extra words, it is ½ point off. Remember not to take off more than 2 points per problem. E. Previous Topics. Lesson 1. Translation from English to German Hallo. Ich heiße Wolfgang. Ich bin ein Junge. Wie heißt du, und wie geht's? Danke. Auf Wiedersehen. Guten Tag, Wolfgang. Ich heiße Monica. Ich bin ein Mädchen. Mir geht's gut, Danke. Gute Nacht und Tschus. Lesson 3» Freizeit/Test Answers

Guitar/Chord Reference. = Open Chords = Open chords tend to sound "richer" than corresponding barre chords due to the fact that open strings resonate freely without any hindrance. Open chords typically sustain longer than their barre chord equivalent. An open chord is any chord that has one or more strings sounded without being fretted. Guitarists tend to use this name to refer to the chords that contain open strings that are played in the first position (first four frets). Barre chords. Barre chords use a movable shape that can be shifted up in pitch and down in pitch along a string to give different keys. Open seventh chords. Seventh chords, strictly speaking from a music theory perspective, means any seventh chord, including major, minor, dominant seventh, diminished and so on. In a beginning guitar context, however, "seventh chord" often means a dominant seventh chord, which is a major triad with a flatted seventh. The G dominant seventh chord, or G7 chord, is the notes G, B, D and F. Chords in C major. Note that the chords in the key of C major consists of 3 major chords, 3 minor chords and 1 diminished chord. This holds true for all major keys.

Urdu/Cover. Urdu

Statics. Objective. By the end of this course, you should understand the fundamentals of forces and moments, and be able to solve equilibrium problems for rigid (non-deformable) bodies in both two and three dimensions. What You Should Already Know. In order to completely comprehend the material in this course, you should have a firm understanding of all math leading up to Calculus I. Also, an understanding of basic physics, as well as technical sketching is useful. Table of Contents. Acknowledgement and Further Reading. Acknowledgements and Further Reading Printable Version. There is a printable version of this book.

Amateur Radio Manual/Conductors and Insulators. Certain elements, like copper in our discussion on atoms, have their valence electrons held weakly in their outer orbit. By supplying energy to the material (one way would be to heat it), we can make the electrons move randomly from one atom to the next. We could also attach a negative source of energy that repels the electrons and attach at the other end a positive source that would attract the electrons. This would force the electrons to move from the negative end to the positive end. We call that net movement of electrons 'electric current'. Substances that have this ability are known as conductors, and most metals are conductors of electrons. Insulators, on the other hand, have their valence electrons bound tightly to the nucleus of the atom. They will not, under normal circumstances, allow the electrons to move easily by supplying energy to the material. However, note that by supplying enough energy (like a lightning strike) we can force even tightly held electrons to move. Common insulators are porcelain, rubber, glass, and plastic. Be cautious with plastics however, some of them can be very good conductors and it is not easy to tell one from another.

Statistics/Testing Statistical Hypothesis. There are many different tests for the many different kinds of data. A way to get started is to understand what kind of data you have. Are the variables quantitative or qualitative? Certain tests are for certain types of data depending on the size, distribution or scale. Also, it is important to understand how samples of data can differ. The 3 primary characteristics of quantitative data are: central tendency, spread, and shape. When most people "test" quantitative data, they tend to do tests for central tendency. Why? Well, let's say you had 2 sets of data and you wanted to see if they were different from each other. One way to test this would be to test to see if their central tendency (their means for example) differ. Imagine two symmetric, bell shaped curves with a vertical line drawn directly in the middle of each, as shown here. If one sample was a lot different than another (a lot higher in values, etc.) then the means would be different typically. So when testing to see if two samples are different, usually two means are compared. Two medians (another measure of central tendency) can be compared also. Or perhaps one wishes to test two samples to see if they have the same spread or variation. Because statistics of central tendency, spread, etc. follow different distributions - different testing procedures must be followed and utilized. In the end, most folks summarize the result of a hypothesis test into one particular value - the p-value. If the p-value is smaller than the level of significance (usually formula_1, but even lower in other fields of science i.e. Medicine) then you reject the null-hypothesis, but this does not mean you accept the alternative hypothesis. The p-value is essentially the probability of obtaining a test statistic at least as extreme as the one observed. If the p-value is greater than the level of significance you fail to reject the null-hypothesis, but this does not mean that the null-hypothesis is correct.

Conworld. Creating Your Own World. "Conworld" is a shortened form of "constructed world". Thus, "conworlding" is world constructing, (otherwise known as world building) the art of creating fictional worlds. The ideal conworld is one with depth, consistency, and beauty, which is why Tolkien's Middle-earth is often held as the best existing example of a conworld. But conworlds are usually as beautiful as they are difficult to make. Conworlding is a many-faceted process, and can be divided into a large number of sub-fields, each of them with its own enthusiasts. For example, conlangers are people who like to make their own languages (known as "conlangs", short for constructed languages). Conmappers like to draw maps of fantasy worlds. Consports enthusiasts dream up games that might be enjoyed in a fantasy world. In general, the prefix "con-" in front of any real-world field turns it into its conworlding counterpart: conmusic, conart, conpoetry, conhistory, consocieties, conreligions, conphilosophies... the list goes on. Name any area of study, and chances are that a conworlder has dabbled in it already! Many people have had conworlding ideas before: a sketched map, a drawing of an outlandish race, or a simple secret language. At this point budding conworlders ask: "Now what?" So I have a map — How do I decide where the mountains go? How do I make the language sound cooler and less boring? How do I make up impressive mythologies? Can I create music that doesn't sound like any sort of music on earth? It might seem that for really thorough answers to those questions — if you don't care how much time or effort it takes to get them — you would want to research the actual branches of science that deal with those things: geology, linguistics, anthropology, music theory, etc. Doing it that way could take an enormous amount of time and effort, though. These are all huge subjects, and the things about them that are of most interest for conworlding may not be the things that are of most interest to specialists in those fields. Details that would be of great value to you may be buried in a sea of details. High-level insights of the sort you need for conworlding may be entirely absent from the literature of the subject, because the sorts of alternative situations that matter to a conworlder may not be what experts in the subject spend their time on. What you need is a guidebook, not to the whole subject, but to the things about the subject that especially matter for conworlding. That's where this series of books comes in. We'll tell you what you need to know for conworlding, skipping over the superficial tourist traps, and including the really interesting sights that aren't on the standard tour. So pick an area that interests you, and start creating! The Way of Con | Example Conworlds | Writing fiction set in your conworld Conplanet | Conmap | Conlang | Consociety | Conhistory | Conreligion | Conphilosophy | Conart

Conlang. Conlanging is the craft of creating languages. People create languages —conlangs— for all sorts of reasons, practical, theoretical and artistic. This book will show you how. The book has three parts, each aimed at a different level of experience; they are meant to be read in order, but more proficient readers may skip earlier sections.

Conlang/FAQ. Here are answers to some frequently asked questions related to conlanging. What's a "Language"? There are many ways that people communicate with each other, but we don't usually call all of them "language". So presumably, any definition of the word should be somewhat selective. When "linguists" talk about language, they usually refer to communication that uses very specific parts of the brain (the and areas), and that has, as a result, some very peculiar characteristics that may be due to the architecture of those areas. For example: If we follow all of the above rules, then there are just two or three basic sorts of languages in the world — spoken languages, like English or French or German (it doesn't matter if they're sometimes represented in writing); sign languages, like American Sign Language; and, to some extent, written languages. Encodings, like Morse code, Semaphore, etc., aren't language in themselves, although they can be used to directly "represent" language. The status of written language is a bit complicated. Writing is often treated as just a representation of spoken language, in which case it's an encoding and not language in itself. There exist conlangs that are purely written, though, with no spoken form at all, like ; these clearly aren't encodings of something else. They might fail the test of being learnable natively — but most conlangs are never learned natively by anyone (the biggest exception being Esperanto, with perhaps a thousand native speakers), so whether most conlangs "could" be learned natively is already a matter for speculation. When a spoken language has an extensive literary tradition, the spoken form of the language tends to change faster than the written form, so that after a while the language has two different registers — a formal (or "literary") register and an informal (or "vulgar") register. This effect is called . The different registers aren't "usually" considered separate languages as such; but since, for example, written English is often the common language shared by native speakers of English and American Sign Language, some have suggested that perhaps written English should be considered distinct from both. That would mean that if you both speak and write English, you're bilingual. Also, when any encoding is used intensively for direct communication, rather than just as a transcription of speech, the encoding tends to develop idioms of its own that don't come from the language it supposedly represents. In Morse code, for example, the "abbreviation" for laughter is HI, because of how it sounds "in Morse code" (not because of how the represented letters sound in spoken language):  . That doesn't make Morse code a language, but it's one small step in that direction. Written languages may develop small flourishes like that as well, like . Other forms of communication, like traffic signs, hand gestures (that are not structured signing), dogs barking, bees dancing (even assuming that is communication, which is debated), etc. are not languages, in the linguists' sense. Are there simple and complicated languages? Yes — but probably not in the way most people think. Some languages have been written down for a long time, have lots of literature and poetry to go with them, and have thick grammars too. These languages are "richer" in the sense that they may have a bigger vocabulary and a richer library of cultural links and so on. But they are not more "complicated". Linguists have found that pretty much all languages, from those spoken by the simplest nomads to the builders of great empires, are all about similarly "complicated", in the sense that they all have the complex structures necessary to convey human thought and reason. The aboriginal languages of North America, for example, have been found to have massive verb tables that put Latin and Greek to shame. And while languages like English and Chinese don't have these verb tables, they do have complicated systems of syntax (or sentence structures) that put those North American languages to shame. What about people who say, for example, that "Spanish is easier to learn than German"? Well — a lot of this depends on the way the language is taught in schools, the amount of sheer memorization demanded of beginners, and how "similar" the language is to your native language. If you're a native English speaker, for example, you may find Japanese baffling, but Korean people usually find Japanese easier to learn than English! Simple languages do exist, in two ways. Pidgins are broken, halting "languages" that people who can't speak each other's languages end up speaking. If these pidgins are taught to children in a community, however, they tend to become full languages within a generation — what we call creoles — so a pidgin can be seen as a new language in the process of birth. On the other hand, dying languages are languages that few people speak, and therefore aren't really being taught to children — these languages tend to get simpler and then die out. When did language begin? It's very hard to know, since we didn't have tape recorders back then. We are reasonably sure, however, that language has been spoken for a very very long time, tens of thousands of years at least, many centuries before agriculture or civilization began anywhere in the world. This is because all people everywhere today, in every corner of the world, speak languages as complex as everyone else's. By the way, languages did not begin in Egypt or Sumeria (as far as we know, anyway). Those were just the first cultures we know of to "write down" languages that they already spoke. Languages must have been spoken by all human beings many millennia before that. What's the difference between a language and a code? A language has a unique grammar, phonology, vocabulary, and set of "roots" from which new words can be derived. All natural languages are descended from parent languages, as well, though for conlangs this is not strictly necessary. A code or cipher, on the other hand, is merely a way of changing one language into something else. Codes and ciphers have no set grammar, vocabulary, or anything like that, and usually exist solely for the purpose of obscuring communication. Too many people will get a dictionary and create a single counterpart for every word in there and then proclaim, "Look! I invented a language!" This isn't altogether a new language, though. Conlangers call this sort of vocabulary-replacement a relex, and it's one jumping-off point to get into creating languages; but there's more to a real language that just its dictionary. What's the "Sapir-Whorf hypothesis"? If you hang around conlangers for long, you'll hear references to "Whorfianism" or the "". Those are two names for the same thing, which also goes by other names such as "principle of linguistic relativity". Simply put, the hypothesis says that how a person thinks depends on the language they use to think about it. Modern writers usually distinguish between a "strong hypothesis", that your language forces you to think one way rather than another, and a "weak hypothesis" that your language encourages you to think one way rather than another. Nowadays the strong hypothesis isn't really taken seriously by mainstream linguists, but most linguists believe some version of a weak Sapir-Whorf hypothesis. Lots of conlangs explore some version or other of the hypothesis. The idea is most closely associated with Benjamin Lee Whorf, 1897–1941, who studied native North American languages of the Uto-Aztecan family — which are dramatically differently structured from European languages — and suggested that speaking such profoundly different languages would give a person a different way of looking at the world. Einstein's theory of relativity was a recent development at the time, and Whorf likened this linguistic notion to Einstein's theory because physical relativity says that how you perceive the world depends on your physical reference frame, while linguistic relativity says that how you perceive the world depends on your language. Edward Sapir, 1884–1939, was an important figure in the early history of modern linguistics, and Whorf's mentor. Sapir too expressed ideas of this sort. It's pretty common, though, for an idea to get named after somebody without their having ever actually said it; Sapir and Whorf both said things like this at various times, but they weren't the first to do so, never coauthored a paper about it, didn't present it as a hypothesis, and dabbled in stronger and weaker forms without explicitly making the modern strong/weak distinction. Many loglangs are at least partly explorations of the Sapir-Whorf hypothesis; but also some philosophical languages are as well, such as , a well-known conlang attempting to support women's thinking, which was used in a series of feminist science fiction novels. Is there a natural language with <feature>? Some conlangers enjoy inventing weird features for their conlangs, but then discover some time later that there is actually a natural human language that has that feature. A classic case is the "Monster Raving Loony" alignment (we'll discuss alignment in the Advanced level), which was devised by members of the Conlang Mailing List who named it "Monster Raving Loony" because it would create inherent ambiguity in the language — making it impossible to tell which of the two arguments to a transitive verb is the subject of the sentence — and therefore seemed absurd. Only then someone noticed a language in Iran that actually has that sort of alignment. This phenomenon is so common that conlangers have a name for it. It's called anadewism — which is an acronym for another natlang already dunnit, except worse. So, when you're having fun with some really weird feature in your conlang, don't let it interfere with your enjoyment when you discover there's a natlang that does something like it! Is there a conlanging community? Short answer: There is now. A central place to look, from which to work outward to all the other parts of the modern conlanging community, is the . Before the Internet, conlanging was mostly done privately by individuals who had no way of knowing if anyone else shared their peculiar pursuit. In a (now classic) lecture about artlanging in 1931, called "", J.R.R. Tolkien described an experience as a soldier in World War I: J.R.R. Tolkien helped make artlanging somewhat respectable: as an academic and scholar of ancient languages, he not only came out publicly as a committed designer of artistic fictional languages, but used those languages to create a hugely successful series of novels. When the internet came along, people who had never before been able to "find" others with the same eccentric interests began to discover each other and form on-line communities, and one of these groups was conlangers. The conlanging community formed especially around the , created in 1991, which was the origin of the term "conlang". The first was held in 2006, and the , which amongst other things now runs the conference, was formed the next year. Are there awards for conlanging? There is one, that the conlanging community generally respects. Since 2006, conlanger David J. Peterson has given an award he calls the to one conlang each year that he found especially worthy of note. The award is, he cheerfully admits, not sanctioned by any larger body, it's just his own arbitrary choice; however, the Smiley Awards are respected in the conlanging community because Peterson, and his opinions, are respected in the conlanging community. The languages Peterson has selected are generally already fairly well-known and respected in the community. For each he writes an essay, explaining interesting features of the language and ending each essay with a section on "How [this language] Has Made Me Smile". The essays are of interest in themselves, for the insights they offer into the art and craft of conlanging. Is there professional conlanging? Until about 2009, it might have been tempting to answer "no", despite a few scattered cases. But, that was the year the movie "Avatar" was released, and the year HBO hired a conlanger to create languages for their planned TV series "Game of Thrones". Since then the answer has to be, at least somewhat, "yes". Before then, there were a few isolated cases of TV or movie conlangs. The earliest we know of was , back in the 1970s; children's TV producers Sid and Marty Krofft hired a professional linguist, Victoria Fromkin, to create a language for a race of primitive humanoids for TV show "Land of the Lost". The first "widely known" conlang on-screen was , created for the 1984 movie "Star Trek III: The Search of Spock" by linguist Mark Okrand at the behest of the movie's director Leonard Nimoy, based on some sample phrases devised for "Star Trek: The Motion Picture" by James Doohan. It was still largely perceived by the general public as an aberration within Star Trek fandom. In 2009, though, James Cameron's "Avatar" became one of the highest-grossing movies ever, prominently featuring conlang for which Cameron had hired a professional linguist (though not a conlanger), Paul Frommer. Then, in 2011, HBO's TV series "Game of Thrones" began, featuring and conlangs. HBO had gone through the (LLC) in 2009 to advertise for a conlanger to create languages for the new series (under a tight non-disclosure agreement, of course), and LCC co-founder David J. Peterson won the contract. Peterson has since received other TV/movie conlanging contracts. Peterson remarked in his 2015 print book "" that movies and TV are a small market for conlanging skills, and suggested book authors might enrich their material by teaming up with conlangers to create linguistic backdrops for their story worlds. What is the earliest conlang? The earliest example we know of a constructed language, as such, is , described in the 1100s C.E. by , a German Benedictine abbess. Lingua Ignota has been studied by professor on English of the University of Rochester, whose book on the subject, "Hildegard of Bingen's Unknown Language: An Edition, Translation, and Discussion", came out in 2007. (Professor Higley is the creator, under pseudonym Sally Caves, of the highly regarded artlang .) Lingua Ignota is apparently a partial relex of Latin, using Latin's grammar and drawing on its vocabulary while introducing more than a thousand new words, and written in a constructed alphabet of 23 characters. Hildegard of Bingen has long been considered a saint in various branches of Catholicism. After a long and rather muddled procedural relationship with Rome, she was made a Doctor of the Church in 2012 by Pope Benedict XVI, resolving her status as a Saint of the Church as a whole, and making her only the fourth woman recognized as a Doctor of the Church — basically, a saint for her contribution to Catholic thought. Saint Hildegard's feast day, September 17, has gained some traction in the internet conlanging community as a conlanging holiday, when conlangers wish each other a happy Saint Hildegard's day.

Conlang/Beginner/Sounds. Spoken language is much older than written language. Many beginning conlangers try to build their first languages out of written words without paying too much attention to what they will sound like, but this approach, while usable, is really the wrong way 'round. Before any written language existed, all the rules that govern how languages work — the rules of grammar — were already in place; what they determined was how language was built from patterns of sound. What sounds will you have? The first step is to decide on what sounds to use in your language. No languages use precisely the same set of sounds; for example, the sound "th" in English does not occur in most other languages (although it does in some, such as Swahili, Greek, and European Spanish); conversely, many languages contain sounds that English does not use at all. You probably already know that sounds are classed as "consonants" and "vowels". In deciding on what sounds to use in your language, it often helps to consider these two categories separately. A chart of consonant and vowel sounds is available in an appendix. For now, don't worry about the symbols used; just enjoy hearing some of the exotic sounds you might want to add to your language! But don't get too exotic; make sure that you can pronounce all the sounds you're going to use, and that you can tell them apart easily. (There will be plenty of time for building conlangs that you can't pronounce yourself "after" you've built ones you can — like a juggler practicing with eyes open before trying it blindfolded!) Another guideline is: don't add more sounds than you will actually need. If you want to use lots of non-English sounds, maybe think about deleting some sounds that English does use as well. But regardless of what sounds you ultimately decide to use or not use, remember that it is important not to throw in every sound you come across; limit yourself to a system of sounds, rather than every sound that exists. If you find yourself with 50 sounds without a good reason why, you have probably gone overboard. The sounds should also be similar to one another in some way; avoid having "freak" sounds that have no relatives. For example, if you have an aspirated stop (a hard consonant like "t", with a puff of air after it), try to have more than one (but not "every" aspirated stop). Choose a convenient way to spell out the sounds you've chosen, so that you can easily write about them, and be sure to write down a clear explanation of just what your spelling rules are. It's a good idea to imitate standard descriptions of your sounds, rather than devising your own; that's the best way to be sure it's clear — even to you, some time later — just what sounds you intended. In the Intermediate level of this wikibook, we'll cover the computer-friendly notation CXS (short for Conlang X-SAMPA), and its big brother IPA (the International Phonetic Alphabet), which are ways to spell out sounds without depending on the spelling rules of any particular language. What sounds can go where? When you have your sounds, you will have to work on ways of putting them together. Languages differ greatly in this respect: for example, English usually requires every syllable to contain a vowel; even words with no vowel written, such as the mathematical term "nth", are pronounced with one — "enth". Not all languages follow this rule; some, on the other hand, require every syllable to "end" with a vowel. If you are going to allow consonants to come after vowels at the end of syllables, you might only allow one consonant, or you might allow a cluster (as English does). Some sounds might be prohibited from certain positions; for instance, the "ng" sound in English can never begin a word, but in Tagalog it can. English allows many clusters of consonants, but prohibits many others: a word may begin "str", but not "zdr". You can make your own decisions on what clusters to allow; Russian and Polish, for example, have no problem with clusters like "zdr". What sounds do I want? The types of sound used in a language (especially a themed language, such as Elvish) depends on the theme itself. For example, an Elvish language would be very liquid-heavy with many approximants while Orcish would have fewer gliding sounds and more gruff chokes. Keep in mind that there are two kinds of sounds: voiced and unvoiced. Feel free to pick and choose, but remember that if your people can make a voiced sound, they can most likely make a voiceless one, and vice versa.

Conlang/Advanced/Grammar/Forming words. Polysynthesis. A polysynthetic language is characterized usually by verbal inflections to the point that word order is largely free. Natlangs that are polysynthetic include Mohawk. It is common in North American Indian languages. There are few polysynthetic conlangs, like Bp@x’àãókxá, Noyatowa, Ilothwii and Terpish. A polysynthetic language generally marks the verb for the number, person, and class (if there are noun classes) of the subject, and sometimes the direct object. The verb is generally marked through affixes that may be prefixes or suffixes. The language may be agglutinative or fusional. In addition, tense, aspect, and any other information about the verb are usually marked on the verb. Here's a hypothetical example:<br> In addition, it is frequent for polysynthetic languages to incorporate nouns. This means that the noun forms a compound with the verb. To illustrate again:<br> A great deal of explanation can be found here:<br> http://zbb.spinnwebe.com/viewtopic.php?f=10&t=1253 Jeff Burke has written this description of polysynthetic languages: Polysynthesis is a grammatical phenomenon most famously present in many North American Indian languages; the Algonquian and Iroquoian tongues are the most well-known. These languages, instead of using case endings on nouns and conjugational endings on verbs, mark both subject and object inside the verb; further, subject and object inflections are considered the actual arguments of the verb, while any free-standing nouns associated with a verb are like dislocated topic phrases. Here is an example from Mohawk, an Iroquoian language spoken in upstate New York and southern Ontario: Teiotahià:kton wá:keke’ Nominalized and rendered in normal English, this is 'I-ate a-banana'; but a more literal translation would be 'A-banana, I-ate-it'. The pronominals 'I' and 'it' (the arguments of the verb root -k- 'eat') are expressed via the prefix ke-, which indicates a singular first-person subject and a singular third-person object. ke- is, then, akin to noun case and verb conjugation fused into a single marker and attached to the verb. Mohawk has some fifty-odd of these pronominal prefixes that express subject-object combinations; and a prefix is mandatory on every verb. By contrast, the noun teiotahià:kton 'banana' stands in relation to the verb wá:keke’ only indirectly, as a topical phrase stands in relation to a central clause in English. Cheyenne, an Algonquian language spoken in southern Montana and Oklahoma, also marks subject and object on the verb, but does so differently; instead of a fusional marker, it uses a prefix for subject and a suffix for object. Witness: Hetane návóómo Literally translated, this means 'A-man, I-saw-him'. Hetane is the noun 'man' standing in relation to the verb návóómo 'I-saw-him' like a topical phrase. Ná- is the prefix for a singular first-person subject; -o is the marker for a singular third-person object. In addition to marking both subject and object inside the verb, polysynthetic languages often make use of noun incorporation. This is a phenomenon where a noun becomes, in essence, an inflection on a verb. Incorporated nouns can be, depending on the language and circumstances, direct objects, indirect objects, subjects, locatives, and of other kinds. Mohawk makes heavy use of incorporation, as in: Watia’tawi’tsherí:io This translates as 'It-is-a-good-shirt', where the noun root atia’tawi (a word that can be used to refer to basically any upper-body garment) is present inside the verb. Cheyenne also uses noun incorporation on a regular basis: Nátahpe’emaheona This verb, meaning 'I-have-a-big-house', contains the noun morpheme maheo 'house'. Noun incorporation can look bewildering, but is best understood in terms of English compounding. Babysit is an example of a word with an incorporated direct object; and words like deer-hunter and manslaughter make use of the same kind of incorporation." The headmarking inflections can be better understood by thinking of Romance languages like Spanish, which inflects for details about the subject. Polysynthetic languages take this concept further and inflect the verb for details about the object as well.

Introduction to Psychology/Child and Adolescent Psychology/Childhood and Sociology. Sociology as a science of the social phenomena is interested in "Infancy" as an object of study under multiple aspects; we will quote only some examples: Another phenomenon was analyzed very finely by sociology: c'est the increasing sum of pocket money at the disposal of the child which was planned in term to be able d'achat d'un specific group of the company which became the privileged target d'une publicity specifically conceived with its intention. Sociology also highlighted that in the various social layers which make a company, the status and roles of the members d'une family are not in the same way defined. Aujourd'hui one can also - grace, inter alia, with sociology - evaluate health or pathology d'un family group by holding account of its behavior vis-a-vis with waitings qu'a the company towards him. This last point forms part of the theorization d'une particular psychological therapy qu'est the family therapy that, for lack of place, we will not n'aborderons here. A last point - in particular compared to sociology - must be underlined: two close sciences (here psychology and sociology) can have the same subject of study (Infancy) but arrive at apparently contradictory results if one is unaware of that the point of view on an object of study is never same the science with the other and that methodologies diverge. Thus, sociology studied the evolutions of the role and statute of the father and the mother with l interior of the family following l emancipation of the women, and how the infant was implied in these changes. In parallel, the psychologists highlighted that simultaneously with this evolution in the imagination of the infants the mother always represents love, protection and permissiveness whereas the father continues to represent the law and repression. This point must point out qu'il to us is necessary always much prudence when one wants to generalize a phenomenon observed and more still when one seeks to transpose it from one science to another.

Conlang/Intermediate/Writing. Scripts, or writing systems, are one of the first things many people notice when they come in contact with another language. Many people, at some point in their life, have tried making some sort of "code", with a one-to-one correspondence between their symbols and their native language's letters. Read on to learn how to make a realistic script for a language. Types of Script. There are five main types of scripts. This page lists them in order from most to least evolved. All these systems have different advantages and disadvantages, for example, the logographic writing system would be useful if a language had many different dialects, but an alphabet would be useful if you want to have a higher literacy rate among the speakers in your conlang. Ideographic systems use one symbol for one thought or idea. Since languages aren't made up directly of thoughts and ideas, and writing systems represent language, true ideographic systems do not exist. They will be covered for the purposes of "alien" languages, though. Chinese is often described as "ideographic" — this is either just a loose use of the term to mean "logographic", or it is a misunderstanding — Chinese characters do not represent ideas directly. Japanese kanji come closer to the "ideographic" ideal, with one symbol representing any of several synonyms in context. Alphabets. Alphabets are the dominant writing system in use in Europe and areas formerly colonized by Europe. Basically, they represent one symbol per sound, including vowel sounds. All too often, however, alphabets, especially the Latin alphabet, are more complex. Each symbol often represents more than one sound, sometimes distinguished in the language, sometimes not. For example, English <c> represents /k/ and /s/, <x> /ks/ and /gz/ (as in exist), or /a/, /A/, /{/, /O/, or /@/. The main reason for this is that the Latin alphabet was made for Latin and simply adapted for later languages. English itself had originally used a runic script, as did the Scandinavian languages. Latin written in the Latin script is entirely phonetic. Many alphabets also have combinations of letters representing a completely different sound. These are called "digraphs". In English, the main consonant digraphs are <sh> /S/, <ch> /tS/, and <ng> /N/, plus many others. "Diphthongs", or vowel-combinations, also occur often. English <i> represents /aj/ as well as /i/ or /I/. Some languages make use of digraphs for diphthongs, such as <ei> for /ej/. Note that situations like the above happen very often. As languages change, their orthography (writing system) may adapt, but not always grow to match it. Almost never does a language have letters that represent only one sound but no others. A realistic con-script should not have a direct correspondence between English and itself as well. Diacritics are another method alphabets may use. Creating new symbols can be difficult and hard to remember, so many languages created "diacritics", or small, additional strokes, to letters to mark new sounds. The main diacritics used in Latin script languages are the acute: ' (á,é, etc., and usually mark stress), the grave (à, è, etc.), the circumflex (â, ê), the diaeresis (ä, ë), the tilde (ã, ñ, usually marking nasalization on vowels), the cedilla (ç), and many others. "Ligatures", or combinations of letters, may also be brought in, such as "æ". The symbol "&" is actually a heavily-modified ligature of <E> and <T>, making "et", the Latin word for "and". Some languages, though, do make new letters, which are often based on previous systems. Examples include the "þ" (thorn, /T/), which was derived from a rune (ᚦ) and "ð" (eth, /D/), developed in the Middle Ages, which are used in Icelandic, Old English, and several related languages. Some letters may not make a sound themselves, but do affect other letters. For example, the Cyrillic <Ь> (soft sign) palatalizes the consonant before it. Some letters can perform both a function and a sound, such as the Russian <Я> ("ya"), which both palatalizes the previous consonant and is pronounced /a/. There are a few scripts termed featural which tend to be similar to alphabets but show phonemic features rather than phonemes themselves. The best example is undoubtedly Korean hangul, though featural elements also occur in a few other scripts, such as Japanese hiragana and katakana, which are mostly syllabaries but take diacritics to indicate voicing. Abjads. Abjads are the main writing system of the Middle East. Basically, they mark consonants in an alphabetic fashion, but vowels are not typically marked. The Arabic and Hebrew abjads are entirely composed of consonants. Vowels can be marked, but generally aren't. Arabic has six vowel marks. Three of them, the 'short vowels', are only marked with diacritics. The other three, the 'long vowels', share symbols with some of the consonants. /a/ shares 'alif /?/, /i/ shares yaa /j/, and /u/ shares waaw /w/. When they are treated as consonants or as vowels can be more clearly seen when vowels are shown. Arabic has an additional diacritic called the "sukuun", meaning the letter it is placed over does not have a vowel over it. If the sukuun is placed over 'alif, yaa, or waaw, they function as consonants. If there is no sukuun, but instead a vowel marker, they become long vowels. They can also become diphthongs if they have a sukuun, but the previous consonant has a vowel. So, the following form is pronounced /kaj/: Ø a Y K (where Ø is the sukuun, and remember that Arabic is read from right to left). Since vowels aren't usually marked, pronunciation has to be inferred by context. The sequence "KY" (using English order) can be pronounced: / kaja kajI kajV kIja kIjI kIjV kVja kVjI kVjV kaj / Abugidas. Abugidas are the main writing system of India, other South Asian countries, and South-East Asia. They are basically a group of syllables with a common inherent vowel, which has to be changed with diacritics. All syllables start out with an inherent vowel, usually /a/, and a different consonant: ka, ca, ta, ta, pa, etc. These each have their own symbol. So, say you want to make the syllable <ki>. The diacritic is then added to the <ka> symbol, and negates the /a/. Note that in the Indian and South-East Asian languages diacritics can come before and after a letter instead of only above or below. Hindi has diacritics for all of its vowels and diphthongs — a, e, i, o, u, r, ai, and au. But what if a word or syllable begins with a vowel? There are two ways you could potentially handle this. In most of the abugidas of Asia, there is a set of "independent vowels", which are full letters just like any of the other consonants, and their purpose is only for syllable-initial vowels. The other way is not done in any of the South Asian abugidas, but still doable. Just make a "vowel carrier", a letter that makes no sound, but can carry vowel diacritics, like the Hebrew aleph. Many of these abugidas also contain "Conjunct Consonants", which you don't have to do too. These are basically ligatures, where the form of two letters are combined into one "space", and they together can take a vowel. For example, when "ta" and "ka" are combined, they become "tka", which can take diacritics like any other consonant. Syllabaries. Syllabaries are spread around the world in use. They contain separate symbols for every CV (consonant + vowel) combination in the language, although final consonants have many ways of being done. Here is an example of a typical syllabary, romanized. This is the Cree system: ê pê tê kê cê mê nê sê šê yê wê rê lê i pi ti ki ci mi ni si ši yi wi ri li î pî tî kî cî mî nî sî šî yî wî rî lî o po to ko co mo no so šo yo wo ro lo ô pô tô kô cô mô nô sô šô yô wô rô lô a pa ta ka ca ma na sa ša ya wa ra la â pâ tâ kâ câ mâ nâ sâ šâ yâ wâ râ lâ -h -p -t -k -c -m -n -s -š -y -w -r -l Note that there are also symbols for the vowels alone. To make final consonants (of the CVC form), the last row of symbols, called the "Finals", are added. So, "tak" would be written with two symbols: <ta> and <-k>. Many syllabaries use this method, and it is basically limited to languages with a small number of legal final consonants. Another system for finals, used by the Mayan syllabary system, is the "Principle of Synharmony". This states that a final vowel is marked by reduplicating the previous vowel. For example, a word like "kalo" is done with two symbols, as usual: ka-lo. But, if you want the syllable "kal", the previous vowel is repeated: ka-la. Since the vowel was repeated, it is ignored on the second syllable. This applies for any vowel. But what if you want to make the syllable "kala"? That requires three syllables, adding in a simple vowel: ka-la-a. The second "a" is negated, but returned by the next syllable. A third system, used by Hittite, comprised of two sets of syllables, one set in CV form, and another set in VC form. This way, when a syllable of the form C1VC2 was needed, one would write C1V-VC2, for instance, <ka><al> for "kal". Additionally, when the vowel in question needed to be made long, like "kāl", the pattern became C1V-V-VC2: <ka><a><al>. For "kala" one would simply write <ka><la> as the /l/ would move onto the next syllable. Sometimes, though not always, syllables with a relation, such as the same consonant, look similar. For example, the syllables "ka", "ke", "ki", etc., may look similar. In systems such as in Ojibwe, the vowel signs are changed by simply rotating the symbol around. Examples of Natlang Syllabaries. And many more systems. Semisyllabaries. There is a set of scripts from pre-Roman Spain that sit in an intermediate category between true alphabets and syllabaries. In those scripts, the plosives combine with the following vowels in a single syllabogram — for instance, there is a single symbol for PA, another for PI, another for PE, etc. — but all other consonants and vowels also have single symbols. In such a system, for example, the phrase "barenarkenti" would be spelled with the nine symbols <ba> <r> <e> <n> <a> <r> <ke> <n> <ti>. In fact, it's likely that such systems evolved out of so-called "redundant alphabets", where the stops had separate signs depending on the vowel that followed them, much like the ancient Etruscan alphabet, where the /k/ sound was written <K> before <A>, <C> before <E> or <I>, and <Q> before <U> (the Etruscan language lacked an /o/ sound). Logographic systems. Logographic systems are/were used to write Chinese, Japanese, ancient Egyptian, Mayan, Sumerian, and many other languages. Ancient civilizations created logography first, and then evolved them into other systems. In a pure logographic system (if there were such a thing in nature), each symbol represents a morpheme, or the smallest meaningful part of language. For example, "hand", "red", "place", "-er", "-ist", "un-" and "anti-" are all morphemes. In a logographic system, each of these would get its own symbol. As you can probably imagine, there are thousands of morphemes in most languages, and hence thousands of symbols exist in any logographic system. These symbols are not all random. In general, symbols of words that represent visible ideas or things are often little drawings. (Remember though that writing constantly develops, so after a few thousand years, there wouldn't be too much resemblance left!) For example, words like "sun", "moon", "man", "child", "water", "fire", "left", "right", "dog", "horse", "tree", "flower", etc. are likely to be drawn as pictures. Not all words can be drawn this way. How are you going to draw "love", or "-er", or "anti-"? Different languages had different approaches. In some cases a word with a similar pronunciation is substituted, for example, writing "ant" to mean "anti-". If you do this often enough, you're on your way to a syllabary, an abugida, or an abjad. In some cases however, another picture is drawn to "explain" the new word: for example, you might draw a spear next to "ant" to mean "anti-" — spear means you're opposed, right? In ancient Egyptian, the spear would be set aside as a separate symbol, while in Chinese the spear would be incorporated into the "ant" symbol to make a new symbol for "anti-". (This is why scripts like Egyptian are sometimes called logophonetic, a name also applied to languages using a mix of logographs and some other system.) The choice here is really up to you. In fact, it is estimated that 90%+ of Chinese characters are formed using the above method: taking an existing symbol with a similar pronunciation, and incorporating another symbol to explain the meaning. Over time, however, these characters' shapes have fossilized, and a lot of sound and meaning changes occur, so some characters are made up of symbols that really don't represent their meanings or sounds very well any more. The sheer size of such a system guarantees it won't be pure; bits of it, or whole sections of it, may be sliding toward some other sort of system, and different parts of it may be sliding in different directions. There will be morphemes represented by multiple symbols that don't have independent meanings, and symbols that represent multiple words. Languages using Logophonetic systems. Now, if you have decided what kind of writing system you want, there are three more steps left to take: Writing Direction, Script History, and Mediums of Writing. Then you can get on to the actual script-making. Writing direction. All scripts have a certain writing direction. Latin writes from left-to-right. Hebrew and Arabic write from right-to-left. Mongolian is top-to-bottom. These are the main types of directions accounted for in real Earth scripts: "Boustrophedon" is where on one line a text is read left-to-right, on the next right-to-left, on the next left-to-right again, and so forth. THIS IS AN EXAMPLE ИI HƧI˩GИƎ FO BOUSTROPHEDON .Ǝ˩YTƧ Note that in Ancient Greek, a Boustrophedon language, sometimes the letters would literally be flipped over when reading in the other direction. So, for example, the Greek letter <F> ('digamma') would be <F> when read left-to-right, but the prongs would face left when reading right-to-left. If you would like to stick with one of the above methods, go ahead. Most scripts use them. A few more complex systems are described below: Some scripts can be written in many directions, that is, left-to-right, right-to-left, and top-to-bottom are all acceptable. Chinese and Ancient Egyptian do/did this. In Ancient Egyptian, all of the hieroglyphs with a face would face toward the direction in which to start reading. So, if you were reading right-to-left, all of the hieroglyphs that had a face (or a discernible front side) would 'face' right. In Chinese, it must be determined by context. Another system is the "Rotational" system, a very rare one. As far as we've heard, only one script ever used it, (the Easter Island script). It is similar to boustrophedon, except that the letters also rotate 180 degrees after each line! If you rotate the reading board around after each line, they would look normal. Here is an example of this using English letters: Some other ideas that, so far as we've heard, have not yet been used: Script history. Scripts are not static. They change constantly, just as language does. Compare writing like Ancient Egyptian hieroglyphics and modern Latin script. Believe it or not, modern Latin script ultimately derives from "Proto-Sinaitic", a small collection of Egyptian hieroglyphs. These hieroglyphs were later adopted into Phoenician, where they were drastically simplified and each assigned a single sound. Through heavy contact with the Phoenicians, soon the Greeks adopted their alphabet, but changed some of their consonant letters, representing sounds that don't exist in Greek, into the Greek vowel signs. Sometime, though we're not entirely sure why, Greek started being written in boustrophedon instead of right-to-left, and then ultimately stuck with left-to-right. When this switch occurred, all of the letters were 'flipped' over horizontally, giving the modern-day Greek alphabet. Then the Etruscans and Latins in the Italian peninsula adopted the Greek alphabet with minor modifications, the Latin one ultimately becoming the script now used throughout most of Europe. Cyrillic script also came from Greek, after the Russians' conversion to Orthodox Christianity, and after about 1,000 years of change, the modern Cyrillic alphabet came to be. In Proto-Sinaitic and Phoenician the letter stood for the glottal stop /?/, but Greek lacked this sound, so it became /a/. "A" originally started out as 'aleph, the ox. Later the body disappeared, leaving only the head. Then the head was simplified to a simple line, leaving the most distinctive parts (the horns) intact. Eventually the horns pierced the line, and the letter flipped on its side in Phoenician. In Greek, it was flipped again, and after several lines were trimmed down, it became the modern Latin/Greek/Cyrillic "A". Note the change of complexity. Early writing is almost guaranteed to be some sort of picture-writing like hieroglyphics, where each symbol represents exactly what it looks like. But, as time goes on and writing spreads, for many this just became pointless complexity. The symbols start to simplify and sometimes turn into alphabets. When one literate people start to trade with an illiterate one, their writing system has a very good opportunity to spread. Sometimes one script wins over another. For example, in ancient India, there were two main scripts used: Brahmi and Kharosthi, but Kharosthi fell out of use and now all of the major scripts of India and parts of South-East Asia are descended from it. Sometimes the early pictographic systems never simplify that much. In the Ancient Chinese writing, the characters did change, but many did not simplify as significantly as the Proto-Sinaitic ones. The modern Chinese logographic system is still very complex. The major reform in 1949 was instituted by the Chinese government. One thing to note is the diversity of scripts in Europe compared to South-East Asia. Almost all of Europe uses Latin script or Cyrillic script, but in South-East Asia every country has at least one of its own scripts. This was probably because of the Roman Empire. The Romans unified most of Europe and had their script well established before they fell, and their script stayed. Such an empire did not exist in South-East Asia, leading to the vast diversity of scripts. So, basically, the ancient hieroglyphic systems simplify when they are no longer only for priestly use, and therefore can be abbreviated. For the common person, carefully elaborating each symbol is just a major waste of time. This is still true today, to a lesser extent, but that is where cursive came from. Even the Ancient Egyptian hieroglyphs had heavily-reduced forms, known as "Demotic", and this was used by the common person. You can see demotic, for example, in the middle section of the (image at right). Here's a link to a good chart (external to wikimedia) showing the evolution of a single symbol through the South-East Asian languages: Medium of Writing. The surface upon which a script is written actually does influence the script a great deal. When carved into stone, such as in the Fuþark or other Runic scripts, the letters tend to be very angular and composed of straight lines. Curves are harder to do in stone than on paper. Also, despite being carved on stone in the Rosetta Stone, the Egyptian Demotic script is much more 'fluid' than the hieroglyphs, and it generally was written on papyrus. The ancient Sumerians wrote on clay, using a reed stylus to impress symbols on it. This also gives it a very unique look. This type of writing is known as "Cuneiform". Some modern languages, such as , retain their unique scripts from the past. The rounded shape of Burmese stems from the fact that it was originally written on palm leaves, which would tear if there were too many straight lines. In the mixed-case systems of Latin, Greek, and Cyrillic scripts (meaning there is both an "upper-case" (majuscule) and a "lower-case" (minuscule)), the lower-case forms came from cursive versions of the capital letters. Now, if you have thought about your script and chosen a script type, writing direction, and a medium, now you are ready to create your own script.

Conplanet. If you want to create your own cultures and societies, they will need a ConPlanet, or at least a local geography, to influence their beliefs, culture, and interactions. The materials provided in this section deal with how to create a realistic world for your peoples to inhabit. Geoff Eddy has an excellent guide for creating planets , which can be extremely helpful. Another website that deals with the scientific side of creating worlds is Anne Viau's World-Builders.org. The members at Unilang started a wiki online called ConPlanet allowing users to participate and interactively construct their con-nation alongside others in the conworld. Table of Contents

Conmap. If you've thought about the geography of your planet, you'll eventually need a ConMap to organize the information. This section deals with how to make good, realistic, and eye-pleasing maps. Computerized mapping. Mapping software tools provide a wide array of options for creating maps at many different levels as well as rendered scenes of landscapes based on those maps.

Conhistory. Our history has determined almost every aspect of lives. It has influenced where we live, our religious beliefs, the languages we speak, how we govern ourselves, relations with others around the world, and many other things. Just as Earth has thousands of years of human history shaping the modern world, so would a conworld have its own ConHistory, whether it is longer or shorter. The information in this wikibook will help you develop your own conworld's history and to shape its present.

Conlang/Types. Conlangs are classified into types and subtypes based mainly on why they are created. The three basic types are "enge"langs (engineered languages), "aux"langs (auxiliary languages), and "art"langs (artistic languages). Whatever your reason for making a language, it's good to keep always in mind why you started it in the first place. Engineered languages. Engelangs, sometimes called englangs, are conlangs designed to meet objective criteria, rather than subjective goals like "elegance" or "ease of use". For example, one might design an engelang so that the arrangement of sounds in a word classifies its meaning; or so that its grammatical structure imitates formal logic; or so that its expressions conform to a certain ideology or point of view (say, Taoism, or feminism). Subjective goals are always around — motivating the choice of objective criteria, and filling in gaps in the language design that the objective criteria don't address. As long as the technical criteria take precedence when deciding features of the language design, it's an engelang. Be aware (and beware) that the names for this type of conlang and its subtypes vary a bit across the conlanging community. What we're calling "engelangs" here, some conlangers call "loglangs" (a term we're using just for the ones that implement formal logic); and some other conlangers call them "philosophical languages" (a term we're using for a subtype of engelangs distinct from loglangs). Logical languages. Loglangs are conlangs built around the structure of formal logic. They are usually designed to investigate how the human mind would work when using a language with that structure. Logical languages tend to have few or no irregularities and be similar in style to computer programming or markup languages. They advocate a logical and consistent architectural structure of utterances. Lojban, a language created to test the Sapir–Whorf Hypothesis (the idea that language shapes the operation of the mind), is considered archetypal of the genre. Others are like Ithkuil, a language created by John Quijada: Ithkuil exists as an exercise in how human languages "could" function. These often overlap with philosophical languages. Some examples of loglangs: Philosophical languages. Philosophical languages are conlangs constructed to meet some philosophical goal. This goal can be to explore how the mind works by altering the fundamental structure of the language (which is the aim of some loglangs, such as Ithkuil), or it can be to see if language is even "possible" when certain elements are changed. In general, philosophical languages are experimental. In some of them, for example, all the words for manmade objects (artifacts) might begin with the same letter, t for instance, all the words for pieces of furniture would begin with to-, the word for "chair" would be "tod", words for different types of chairs would begin with tod-, organisms with v, plant species with ve- while animals would begin with vu-, all vertebrates with vuz-, mammals with vuzu- and rodents with vuzum-. A common criticism of languages that use such a word categorization system is that the words that are most similar in meaning and topic, and will therefore most need to be distinguished from each other, will sound too alike, and become too confusable to learn, even though the goal of these languages is usually to make memorization easier. In a few of these languages a single phoneme or very short (two-letter) syllable will indicate an element of meaning, such as "light/vision", "female", or "many". Some examples of philosophical languages: Auxiliary languages. Auxlangs are designed to help ease communication between two or more linguistically diverse communities. They use simple phonology and grammar to try to make them easy to learn. Their grammars are made in such a way as to express the widest range of meanings possible. There are many Auxlangs, and some of them were among the first constructed languages ever made. Some examples of auxlangs: Many auxlangs borrow their vocabulary entirely from the Indo-European languages — often from a mix of Romance and Germanic languages, but most often entirely from Romance languages. As a result, the vocabulary and general method of reaching the goal of universality sound a lot alike from auxlang to auxlang. These auxlangs are often called "Euroclones". More recent auxlangs that take their vocabulary from more diverse sources and use non-Indo-European grammar include , , , and . Artistic languages. Artlangs are created for a wide range of reasons: fleshing out works of fiction, fun, experimentation, or even historical study (colloquially called "if-langs"). Most people who create artlangs do so simply because they enjoy it. Several artlangs have gained high visibility in popular culture in recent years, such as Klingon, created for the Star Trek franchise by professional linguist Marc Okrand; the many Elvish languages, especially Quenya and Sindarin, in Tolkien's Middle-earth; and Dothraki, created by conlanger David J. Peterson for the "Game of Thrones" television series. Fictional languages. The most familiar and general subset of artlangs are fictional languages. These are spoken by the inhabitants of the fictional worlds of a book, movie, television show, video game, comic, or toy, such as Middle-earth, the Star Trek universe, or the game Myst. These worlds in which they are spoken are called conworlds, inhabited by fictional concultures. The conworld influences what words the language will have for flora and fauna, articles of clothing, foods, objects of technology (such as bricks, cannons, or telephones), sports, music genres, ethnic groups, religious concepts, and place names. The culture will also have an influence on some things like verb tenses (how your people view the future and the past, or whether time should even be grammatically indicated at all any more than place should), pronouns (whether the speakers need fine enough shades of "we" to distinguish the concept of "you and I" from "them and I", or whether they have different levels of formality for "you"), and how kinship terms are split up (some languages have different words for older and younger brothers, others do not distinguish "brother" from "sister", and some have different words for the sister of a sister and the sister of a brother). Tolkien started out inventing languages for his amusement and then retroengineered a fictional universe to have a world in which these languages would be spoken. Since the Internet became popular, many people have now become able to put up information on their conlangs and associated conworlds on their sites, and these have become famous. Verdurian, the language of Mark Rosenfelder's Verduria on the planet of Almea, is often invoked as a symbolic representative of these Net-based fictional languages. Some examples of fictional languages: Altlangs. Altlangs are also known as "What if?" languages or if-langs. They speculate on an alternate history and try to reconstruct how a family of natural languages would have evolved if things had been different. What if King Harold had won the Battle of Hastings? What if the Polynesians had settled in Central America during the time of Meso-American Empires? What if Alexander the Great had not been able to conquer Egypt? What if Greek civilization went on to thrive without a Roman Empire, leaving Greek and not Latin to develop several modern descendants? The language that "would have" evolved is then traced step by step in its evolution, to reach its final form. The revered grandfather of this genre is Andrew Smith's Brithenig, which attempts to determine what Romance languages would have evolved into had the Romans displaced the Celtic people in Great Britain. The vocabulary of Latin is altered through the same evolution that befell Welsh from the evolution of the Celtic languages through the present day. An altlang will typically base itself on the core vocabulary of one language and the phonology of another. An altlang will ideally have meticulous understanding and admirable imagination as to world history, sturdy knowledge of linguistics, and ingenious improvisation when it becomes necessary to "toss it up". Some examples of altlangs: Personal languages. Personal languages are languages that are created by and belong just to the inventor, for just the inventor to see, or perhaps to show off. A personal language is created for the ultimate purpose of creating a language. There is no conworld motivating it, no people whom the creator actually expects to speak it, no product that will be manufactured in its language. A personal language is considered by many to be artlanging in its purest form, although a personal language may well have no artistic intention behind it. A personal language may be invented to create a beautiful language or for self-expression. It may be invented to give out a tribute to a language or language family the creator really likes, attempting to capture the flavor of the original as much as possible, or it may be created just for the fun that there is in creating a language. Personal languages are often created as practices in linguistics; a conlanger learning about ergativity might write out the grammar of an ergative conlang in order to understand how ergative languages work. Some exist to test outlandish phonologies or orthographic systems, or have hundreds of noun cases or tens of millions of possible verb forms. Many are invented simply because people love constructing languages! The creators of personal languages often share their languages and update their progress over the Internet, and many habitually scrap an old conlang project that hasn't gotten beyond a lexicon of 50 words and start a new one. These personal languages tend to have short lifespans, but others are developed for years on end as their creators try to become truly fluent in them, perhaps using them for diaries and other writings. Micronational languages. Some artlangs are micronational languages — like fictional languages, but their creators make them real. They declare territory, issue official flags and currency, and recruit citizens, then have the citizens learn the language. These are the languages of micronations, sometimes created for entertainment, but often breakaway nations that are created for political purposes, declaring themselves to exist alongside UN-recognized nations (such as Sealand, the Conch Republic, or Atlantium). The members of these micronations meet up and speak the language they have learned when they are participating in these meets. The language and its creation belong to all the citizens of these micronations. They determine the direction of its evolution, invent new grammatical constructions when they discover it is necessary, and coin new words as they speak. Other ways of classifying conlangs. In-between goals. The three broad kinds of goals we've described — technical features, cross-cultural communication, and art — aren't mutually exclusive. What if your goal is to see whether a certain technical goal can be successfully combined with your personal aesthetics? Is that an engelang or an artlang? is a conlang with just that sort of goals, and its author has suggested that conlangs should be placed on the interior of a triangle, with the three pure types of conlangs at its corners (the ). Even if a conlang has a single, pure primary goal, there are enough details in any conlang that the primary goal probably doesn't cover all of them. Auxlangs have some artistry in their making — it's been argued (see sources) that artistic merit is part of why Esperanto has succeeded so much better than its competitors. Engelangs may have some artistry in them, too; and artlangs often have some technical aspirations lurking under the surface. A particular class of mixed-goal conlangs with its own name is the fauxlangs, short for fictional auxlangs. These are supposed auxlangs created by characters in a fictional setting, often in an alternative history. Examples include Relexes. A relex is a conlang generated from a pre-existing language by replacing the forms of the words, while leaving most of the rest of the original language unchanged — especially, With both of these unchanged, the conlang is a sort of word-replacement code for the original language. By extension, "relex" is sometimes used as a broad criticism of any conlang seen as too closely copying another language. The largest class of relexes are (by reputation, at least) artlangs whose authors failed to notice that they were copying most of the look and feel of their native language. Not all relexes are artlangs, though, and not all are unintentional. Auxlangs and have both been criticized as relexes of English. The loglang started as a deliberate relex of , since which their grammars and vocabularies have gradually diverged as both languages underwent further development (see sources). Some relexes may be used for specific purposes. For example, the Israeli military uses a relex of Hebrew called "NADBAR". The conlanging term "relex" is a shortening of the term "relexification", borrowed and adapted from linguistics proper. The linguistic term has a narrower meaning: in linguistic , a pre-existing language keeps its grammar but replaces its vocabulary from another pre-existing language. The language from which the vocabulary is taken is called the "lexifier". A priori and a posteriori. Particular features of a conlang can be a posteriori — meaning borrowed from natural languages, rather than invented — or a priori, meaning invented rather than borrowed from natural languages. These terms are most often used to describe the forms of words, as with the words "toki", from the Pidgin word "toki" (talk), and "pona", from Esperanto "bona" (good). An entire conlang may also be described as a priori/posteriori if most of its grammar and vocabulary are of that type. A conlang described as a posteriori usually borrows from several, or even many, different natlangs; relexes are not normally called a posteriori. Classification-based vocabulary is an a priori strategy that has been used in a number of engelangs (e.g., ) and some auxlangs (e.g., ). Most auxlangs make extensive use of a posteriori vocabulary. Diachronic languages. A diachronic conlang is equipped with an internal, i.e., fictional, linguistic history. Since the internal history is fictional, all diachronic conlangs are artlangs; but most subtypes of artlangs include both diachronic and non-diachronic ("synchronic") languages. Tolkien's Elvish languages are the most famous example of diachronic conlanging, with an entire family of languages descended from a common ancestor, . Many artlangs, though by no means all, have at least some suggestions of internal history about them, even if no parent language has been fully worked out. Altlangs are diachronic, by definition. Kitchen sink languages. A kitchen sink conlang is one that has way too many exotic features, all at once for no apparent reason — "everything including the kitchen sink" in an uncoordinated mishmash. Unlike "relex", "kitchen sink" has no neutral technical sense; it's always a strong term of opprobrium. Kitchen sink languages are at the opposite end of a spectrum from relexes: where too little tinkering can produce a relex (that lacks interest), too much tinkering can produce a kitchen sink language (that lacks plausibility). It has been suggested that a conlanger's second conlang — after they've made a relex for their first — is often a kitchen sink language; but even experienced conlangers, tempted by the lure of exotic features, can sometimes fall into the trap of kitchen-sink-ism. Caution should also be exercised, though, in "applying" the term "kitchen sink" to a conlang — not only because it's such a strong term, but because just having many unusual features doesn't "necessarily" make it a kitchen sink language (which is why the term is so strong). For proper use of the term, the many unusual features should be unjustified; in principle, at least, it's possible for many unusual features to occur in a smoothly coherent design, so that they all feel quite natural in context. The catch is that — as David Peterson remarked when awarding the 2007 to , a highly respected conlang with several unusual features — there is a double standard at work between natlangs and conlangs: any bizarre features of a natlang are natural by definition, but the same features in a conlang would have to persuade on their own merits. His case in point is , a natlang with no way of expressing time; no way of counting; a culture with no storytelling, oral history, or art; it can be spoken, whistled, hummed, or drummed; and it has different phonologies for men and women. If it were a conlang instead of a natlang, its creator would have a hard time passing it off as naturalistic.

Conart. No, not the doings of con artists. Art has long been a way for humans to express themselves. Why not have your conpeople make their own ConArt as well? Remember: Table of Contents

Conlang/Intermediate/Sounds. All spoken languages use systems of sounds (called a phonology), and most of these aren't anything like English, including, hopefully, the conlang that you'll soon have. This section should help you. What's in this section? The parts of this section are:

Algebra/Theory. The Natural Numbers. Mathematics requires, in order to avoid confusion or absurdity, an unambiguous definition of vocabulary. While this is true of any science, in mathematics this is achieved "absolutely" through the abstraction of concepts. However, the full description of math as above requires time, and is nowhere elementary. Also, in order to have a true "axiomization", a math built up from the roots, we will have to use the strongest, in the logical sense, statements possible. This makes them powerful for proofs but often sacrifices intuitiveness. Thus, we will concentrate on the later, only rarely using rigour, as necessary. To do mathematics we must start by finding a way to think about numbers that is as above, unambiguous, while at the same time obvious and natural. We thus come up with the natural numbers. Intuitively, we define these as the set N = { 1, 2, 3, ... }. We will say a number is a natural number if it belongs to this set. Soon we will find this needs to be expanded even for elementary treatment, but this set alone already has some interesting properties. If there is a set A such that if we pick an arbitrary number, call it x, and x ∈ N, we say A ⊆ N. In words, A is a subset of N. By x ∈ A we mean that x is "in" A, or that x is an element of A. While we have not defined properly a set, membership or inclusion, we have already a feel for what N ought to be like. Mathematical induction. Principle of mathematical induction. "Let A ⊆ N with the following properties:" (i) formula_1 (ii) formula_2 implies formula_3 "Then A =" N Remark. The principle of mathematical induction is implied by the 'least element principle' (2.1). For, assume that 1.1 holds and let "B" be the set of all elements of N "not" in "A". If "B" has any elements (that is, is not empty) then it must have a least one. Call this least element "n". Then, by (i), formula_4. Thus "n - 1" is a natural number and is not in "B" and so is in "A". By (ii), formula_5 is a natural number which is in "A". But now "n" is in both "A" and "B" which is impossible. So "B" must have been empty. That is, "A =" N. This serves as a fundamental property of the natural numbers, and we, further defining order, will call these numbers well-ordered, primarily because of this principle. In more rigorous terms, we would have to identify a separate axiom, called the axiom of induction, which encompasses this property. However, for our current purposes, this is sufficient. Principle of mathematical induction (modified). "Let A be a set of natural numbers which has the following properties:" (i) "The natural number "formula_6" is in A" (ii) "If" formula_7 "and" formula_2, "then" formula_3 "Then A contains all natural number" formula_7 Numbers. In this section, we shall describe some of the more commonly occurring types of numbers together with some of their properties. Types of Numbers. Natural Numbers, N. As already mentioned, these are just ordinary counting numbers 1,2,3,4...,29... . Note that zero has not been included in this set. This varies with different books or mathematicians and may include zero as a natural number. An important property of the natural numbers is the ordering. Note that natural numbers come with an idea of size so that we can talk about larger and smaller natural numbers. Integers, Z. By the integers, we mean the natural numbers together with their negatives and zero. Although we all, presumably, have a reasonably clear practical idea of how to work with the integers, there are definite problems as to what they actually are. Referring to such things as the 'number line' does not solve these problems because it relies heavily on our intuition. One way that mathematicians solve this problem is to make an artificial construction which produces an artificial object with the properties we expect of the integers. Although we do not use this in everyday mathematics, it gives a precise definition which we can use to justify our use of negative numbers and also provides a model we can use when we wish to develop quite new constructions which are not so intuitively reasonable. We shall not describe this for the integers but will give a brief description next of a similar process starting with the integers and producing the rational numbers. Rational Numbers, Q. With the integers, we have a number system which is closed under addition, multiplication and subtraction. The next step is to produce a collection numbers which is also closed under division (except by zero). This is the rational numbers. Again we should all be able to manipulate rational numbers but there is some problem with what they actually mean. For example, what does it mean to say that formula_11? We usually want the equals sign to denote the fact that two things are identical and the "symbols" formula_12 and formula_13 are certainly not identical. So we redefine what we mean by "equality of fractions". Let us consider the set of ordered pairs of integers with the second integer non-zero; that is, formula_14 and formula_15 (An ordered pair is just a pair in which it is specified which comes first and which second.) We want these ordered pairs to represent rational numbers but on a many-to-one basis. So we redefine equality of these ordered pairs by formula_16 if and only if ad = bc (Read this as (a,b) is "equivalent to" (c,d).) This corresponds to the usual definition of equality of fractions. We can then think of one rational number as being represented by a collection of ordered pairs of integers all equivalent to each other. Two ordered pairs represent the same rational number exactly when they are equivalent. WE can then go on to define, in terms of the ordered pairs, the usual operations of addition, subtraction, multiplication and division. For example, We will define addition of rational numbers by taking an ordered pair for each number and then adding these ordered pairs. There is still a problem however. We need to be sure (without checking each case) that, for example, because formula_17, then also formula_18 What is order? Again, as we try to find a way to define, based on the already established ideas of addition, and the intuitive idea of order, in what sense is a number larger than another. In what way can we arrange the numbers? With N this is easy, we say, if a, b are natural numbers, a < b if there is a natural number c such that a + c = b. From the principle of induction, we can thus order N in the following manner: 1, 2, 3, ... As has been done before with our intuition. With Z, we run into a problem, where do we start? Since the principle of induction does not apply on Z as a whole, we have to write it as ..., -1, 0, 1, ..., leaving "..." on both sides. However, the definition, as before, applies. With Q, clearly formula_19 > formula_20, yet formula_21 is not in N and so our definition fails. The new definition would be Definition: (Order on Q) "Let a, b be rational numbers, then a < b if there is a positive rational number c such that a + c = b." We call a rational c positive if it is equivalent to a rational formula_22 such that n and m are both natural. In other words, if c = formula_23, then c is positive if "pq" is a natural number. A simple exercise would be to show these are equivalent. (Note: Statements are equivalent if each implies the other.) Any set such that for each two elements in it we can definitely say a < b, a > b, or a = b is called totally ordered. The least element property. "Any non-empty subset of the natural numbers has a least element." The words 'any non-empty subset' mean that the subset we take should have at least one element in it. Any set with the least element property is called well-ordered. Thus N is well-ordered as above, while Z and Q are not. Order properties of natural numbers. (i) "There is no largest natural number". (ii) "There are natural numbers which are nearest neighbours in the sense that there is no natural number strictly between them." Proofs. Definition. A proof is simply a mathematical argument designed to convince the reader of some fact. However an intuitive proof differs from an inductive proof. The former being a fact that can be assumed to be an observable constant from daily experiences (e.g. when two test tubes of milk are poured into one beaker, then if we divide the final volume again into the two beakers, we should get full test tubes again (almost). This explains why ½+½ will still be 1. Since this follows from intuition/observation/experience alone it can be considered an intuitive proof.). The latter, inductive proof, is of the type where many intuitive proofs can be combined to get the desired result. For example, we know that pouring two test tubes of milk gave us two units in the beaker, so if the volume of the test tube can be regarded as a unit volume, then "n" such test tubes will give us a total of "n" units of milk in the beaker. Mathematical proof itself is based on natural logic and philosophy. Modern mathematics generally assumes most proofs to be absolute, not without reason though. This allows them to engage in complex problems using purely inductive reasoning. However the basis for all that still remains natural philosophy and logic. This is reflected in Newton's title to a relatively abstract mathematical treatment of his work being titled as 'Principles of natural philosophy'. Mathematical terms. and - 'A and B' means that both A is true and B is true not - This has the usual meaning in English; note that not(not(A)) is the same as A or - This is always what is called 'inclusive or'. That is 'A or B' means that either A is true or B is true or both. for all - This has the usual meaning in English there exists - This has the usual meaning in English implies; if-then - These kinds of statements are at the centre of mathematical reasoning. if and only if; equivalent - 'A implies B' and 'B implies A' Theorem, Proposition, Lemma - They all mean roughly the same thing but are in decreasing order of importance. Corollary - Something which follows easily from a Theorem but for which the statement is not entirely obvious from the statement of the Theorem. Summation Notation. The summation notation is a convenient abbreviation for sums of several real numbers. If formula_24,formula_25...,formula_26 are reals, we define formula_27 The "summation index k" is often called a "dummy index", as it can be replaced by any other letter: formula_28, etc. Sometimes it is convenient to start summation from 0 instead of 1, or from some other integral value. For instance, formula_29, or formula_30, etc. The most important properties of the summation notation can be summarized as formula_31 (additive property) formula_32 (homogeneous property) formula_33 (index translation) formula_34 (telescoping)

Primary Mathematics. This book focuses on primary school mathematics for students, whether children or adults. It is assumed that no calculators are used, to encourage mental arithmetic. A parallel project at Wikiversity is underway to provide teaching tools to parents and educators, whether in traditional or home-schooling environments, at ."

Conart/Music. Conworld : conart : conmusic Introduction. Most westerners are unaware of the great variety there exists in music. Music is by no means the universal language it often is supposed to be. Even in such basic areas as the very building blocks of tonality there exist significant differences between Thai, Indian, Arab, Balinese and European music. In order to be better equipped to create a new system, it is good to have some kind of grasp of what human cultures have created. Therefore, this chapter will mostly analyze a number of musical systems somewhat superficially, and also go into the necessary math. Firstly, we will go into how scales are constructed. Secondly, we will look at some rather peculiar vocal techniques that mankind has come up with. Thirdly, miscellaneous things having to do with the music itself will be dealt with. Fourthly, the social and religious aspects of music will be discussed, and finally I will provide you with some listening advice. The building blocks of music The instrumentation and

Mathematical Proof/Methods of Proof/Proof by Induction. The beauty of induction is that it allows a theorem to be proven true where an infinite number of cases exist without exploring each case individually. Induction is analogous to an infinite row of dominoes with each domino standing on its end. If you want to make all the dominoes fall, you can either: Induction, essentially, is the methodology outlined in point 2. Parts of Induction. Induction is composed of three parts: Weak Induction. Weak induction is used to show that a given property holds for all members of a countable inductive set, this usually is used for the set of natural numbers. Weak induction for proving a statement formula_1 (that depends on formula_2) relies on two steps: If these two properties hold, one may induce that the property holds for all elements in the set in question. Returning to the example, if you are sure that you called your neighbor, and you knew that everyone who was called in turn called his/her neighbor, then you would be guaranteed that everyone on the block had been called (assuming you had a linear block, or that it curved around nicely). Examples. The first example of a proof by induction is always 'the sum of the first n terms:' So the inductive case holds. Now by induction we see that the theorem is true. Reverse Induction. Reverse induction is a method of using an inductive step that uses a negative in the inductive step. It is a minor variant of weak induction. The process still applies only to countable sets, generally the set of whole numbers or integers, and will frequently stop at 1 or 0, rather than working for all positive numbers. Reverse induction works in the following case. Then the property holds for all values formula_18. Reverse induction is also usable in the general case : "to establish the validity of a sequence of propositions formula_19 , it is enough to establish the following (a) formula_1 is valid for infinitely many formula_2 . (b) If formula_22 is valid, then so is formula_1 . It can be the case that we can easily prove formula_24 and if formula_25 for formula_26 so formula_25 for formula_28 . In this case we have (a) for the infinitely many formula_29 . Strong Induction. In weak induction, for the inductive step, we only required that for a given formula_2 , its "immediate predecessor" formula_31 satisfies the theorem (i.e., formula_32 is true). In strong induction, we require that not only the immediate predecessor, but all predecessors of formula_2 satisfy the theorem. The variation in the inductive step is: The reason this is called strong induction is fairly obvious — the hypothesis in the inductive step is much stronger than the hypothesis is in the case of weak induction. Of course, for finite induction it turns out to be the same hypothesis, but in the case of transfinite sets, weak induction is not even well-defined, since some sets have elements that do not have an immediate predecessor. Transfinite Induction. Used in proving theorems involving transfinite cardinals. This technique is used in set theory to prove properties of cardinals, since there is rarely another way to go about it. Inductive Set. We first define the notion of a "well-ordered" set. A set formula_37 is "well-ordered" if there is a total order formula_38 on formula_37 and that whenever formula_40 is non-empty, there is a "least-element" in formula_41 . That is, formula_42 such that formula_43 . An "inductive set" is a set formula_44 such that the following hold: Of course, you look at that and say "Wait a minute. That means that formula_51!" And, of course you'd be right. That's exactly why induction works. The principle of induction is the theorem that says: The proof of this theorem is left as a very simple exercise. Here we note that the set of natural numbers is clearly well-ordered with the normal order that you are familiar with, so formula_56 is an inductive set. If you accept the axiom of choice, then it follows that every set can be well-ordered. Exercises. \le2\sqrt{k+1}-1</math> We know that Now we need to show that it follows that The last statement is clearly true. Therefore, and by mathematical induction, the formula holds for all positive integers.

Conworld/Philosophy. Why make a conworld? Why do people conworld? Why do people conlang? People go about doing these things for very different reasons, and not surprisingly, the results can also be widely different. Some people micromanage when they conworld. They draw detailed maps of plate tectonics and then synchronize these with enormous evolutionary trees; they derive meticulously all of their languages from common ancestor languages, tweaking every single irregular verb; their maps are covered with carefully shaded mountainsides and hydrologically plausible drainage systems. For these people, that final satisfaction of everything fitting together perfectly is where the fun lies. But others disagree; their continents are broad strokes of geometrical wonder that utterly defy geological explanation; their flora and fauna are wondrously improbable; their forests are enchanted with magical beings. How did these magical beings originate? Who cares? For what is the fun of conworlding if you can't have some freedom? Some people willingly and deliberately inject ideas from the real world into their conworld, using their conworld as a kind of test bed for political and philosophical theory (what if an anarchist society existed in ancient times or subjective idealism had practical implications for technology?). People may feel passionately about a real-world culture, or philosophy, and they reflect it into their conworld, when their nations, perhaps, come to resemble greatly those of Medieval Europe, or Arabia, or the Mayans. But others want to create something that is utterly new and completely unlike anything that has ever existed. To them, the real world is boring — and it's what's in your mind that's really unique and interesting! Some people make their conworlds utopias. Their political beliefs are reflected in their conworlds; all of their citizens are happy, productive, prosperous members of what they think would be a perfect society. Along a similar vein, some people make their conlangs poetic and melodic, their conreligions noble and benevolent. But there are others who take on a more realist, even pessimistic view. These people have conworlds filled with slavery, poverty, lawlessness, and war; their conlangs are quirky, if not downright unpleasant; their conreligions initiate bloody conquests and massacres. And what kind of conworld itself constitutes a utopia is as varied as the religious and political beliefs of the utopians who create these conworlds: a world bordering on the modern and futuristic with beeping electronic technology and commerce and endless entertainment; a medieval world in whose Chain of Being everyone lives beneath a Good King figure; an anarchy; a realization of Christian ideals or Sharia; a peaceful, pastel-colored butterfly-inhabited island where there are no wars; a working model of Communism in which citizens greet their comrades; a theocracy below a God Emperor with tight gender roles into which everyone neatly and dutifully falls to please their ancestors. Some people conworld for another, different purpose. They are perhaps hosting a role-playing game and need to construct a background with richness and detail; perhaps they are writing a novel and need some place to set it; or perhaps the conworlds exist for the very purpose of expositing their conception of a utopia. And then there are others to whom the conworld itself is the purpose. To them, the creation "is" the conworld; if they do eventually turn it into the setting of a novel, then the novel is merely an exposition of the great masterpiece behind it — the conworld.

Basic Automobiles. Introduction. This document attempts to describe everyday use of an automobile. The class of automobile considered is an average performance, front-wheel drive consumer vehicle. Accelerator. The accelerator, also known as the "gas pedal" controls the engine output. Pressing the accelerator increases the revolutions of the engine, mainly by allowing more air to enter the combustion chambers, or the cylinders, per revolution. The revolutions for various stages in this section depend on the engine, and every engine has a unique set of values. The "tachometer" gives the value of engine speed at any time. However, an experienced driver is supposed to know the speed of the engine without taking eyes off the road. When the car is first started, the engine moves at a speed called the "idle speed". Many consumer cars provide means of changing the idle speed of the engine. Say the idle speed of an engine is 1000 rpm (revolutions per minute). There is a minimum speed below which the engine will not fire, called the "stall speed", and would be about 750 rpm for our engine. The other bounding value for the engine speed is called the "red line". This is the maximum speed at which the engine can safely operate. For our engine, it is about 7000 rpm. Thus, it is the job of the driver to make sure that the engine speed stays between the stall speed and the red line. Moreover, the accelerator plays a very important role in the over all working of the engine thereby controlling the intake of the air inside the cylinder. Steering. Almost all the vehicles on the road today have some sort of steering wheel which is used to turn the tires. Typically, a rack and pinion mechanism is used which will turn the tires by a few degrees for several rotations of the steering wheel. Some vehicles have a dead zone at the center of the rack, so that you don't have to constantly adjust the steering while driving on the highway. In the normal position, both hands should be on the wheel in the 10-2 position. To make a turn in a vehicle, rotate the steering wheel at the start of the turn. To make a turn to the left while moving forward, move your left hand to the top of the wheel, and pull down to the left. At the same time, let the wheel run through your right hand. As you near the end of the turn, steady the vehicle by moving your right hand to the top of the wheel and pulling down and right. "Do not allow the wheel to spin back on its own!" Even though this is very tempting, if you do, you will very likely lose control of the vehicle. You should have the wheels straightened when the turn is complete, or the vehicle will travel in an "S" shape, which is bad form. Most consumer vehicles are "understeered", as it is easier to handle for novices and unskilled drivers. Also, it is difficult to achieve neutral or "oversteer" in front wheel drive vehicles. Power Steering. Most modern vehicles marketed towards the average consumer has some sort of "power steering" installed. This means that the actual task of turning the wheels is performed by indirect means. Power steering is not preferred in racing cars as they reduce road feedback. However, it is much appreciated by the general public, especially for low speed maneuvers. New technology has come up with a very good solution--the speed sensitive power steering. This kind of power steering gives effortless low speed maneuvers, but firms up at higher speeds so that you can judge the grip of the tires accurately. In general, there are two kinds of power steerings available--hydraulic power steering and electronic power steering. Electronic power steering is the more advanced of the two and is found in more advanced/modern vehicles. However, the feedback in hydraulic power steering is much better, so that driving is much more fun compared to a car with electronic power steering. Turning Radius and Maneuverability. The turning radius of a vehicle is the radius of the smallest circle in which it can turn. Two different values are given--the often quoted value is the "curb turning radius", which is half the width of a road in which you can make a smooth turn without hitting the curb. The other value is called "wall to wall turning radius", which is half the distance between parallel walls where the vehicle can turn. The turning radius of a vehicle depends mainly on the "wheel base" and the "wheel cut" of the vehicle. Wheel base is the distance between the front and the rear axle. Wheel cut is the maximum angle through which the tires turn when the steering is rotated from the center. The smaller the wheel base, the smaller the turning radius, while smaller the wheel cut, the larger the turning radius. It may seem that a larger wheel cut is preferable. However, a larger wheel rotation will lead to more side forces on the tires, which might damage them. Note that when a vehicle turns, the front wheels will have to turn by different angles so that there is no slippage. In a turn, the inner front wheel will have a larger cut. This is achieved by a mechanism known as "Ackerman linkage". One of the modifications that you can make on a stock vehicle is increasing the wheel cut. Given the front and rear overhang, the wheel base, and the wheel cut, we can calculate the wall to wall turning radius for low speed maneuvers for a vehicle. The turning radius is related to the "maneuverability" of the vehicle, and also affects the design of parking spaces and driveways. What complicates the design is that the radius of the vehicle's travel varies continuously. Commercial software is available for such applications, but it takes a very simplified view--"i.e.", that the radius is constant, and equal to the turning radius. While this may enable us to see the absolute minimum space, the assumption is that either the driver stops the vehicle completely before making the turn (a very difficult maneuver without power steering), or that the steering is rotated extremely rapidly. What is more natural is that the vehicle is steered slightly at higher speeds, and more rotation is applied as the speed reduces, with the turning radius being achieved about 20% into the turn. Similar conditions apply to exiting the turn. Aerodynamic Forces and Stability. Modern automobiles travel at high speeds on flat roads, and this leads to large aerodynamic forces acting on the vehicle. The streamlined, close to airfoil nature of many vehicles lead to a large amount of lift even at moderate speeds. Many sports cars attempt to reduce the lift problem by having rear spoilers. Some of the higher end (though not the highest) cars attempt to provide more downward force using a rear wing. Note that such tricks increase the drag and reduce the top speed of the car. Racing vehicles have attempted to deal with instability by lowering the body so that air cannot get between the under body and the road. Non racing vehicles are also expected to handle certain amount of unevenness in their path, so that they have a large "breakover angle". Another method employed is to use a pump to lower the pressure at the bottom of the car, reducing the lift. However, this is not very practical for a standard car. Drag Coefficient. The drag coefficient of a car gives an indication of how aerodynamic the car is. However, note that "CD", the drag coefficient is defined as formula_1 where "V" is the air velocity of the car, and "A" is the frontal area. Thus, a small sports car will have much lower drag compared to a van for the same velocity. Modern automobiles quote a "CD" value of less than .35, but frontal area is what counts in this situation. As can be seen from the above equation, the drag force is proportional to the square of the air speed. Thus the horsepower required to overcome drag force is proportional to the third power of the speed of the vehicle. The rolling resistance is approximately independent of the speed of the vehicle, so that the horsepower required to overcome rolling resistance is proportional to the speed of the vehicle ("i.e." it increases linearly). Thus, it is easy to see why it most sports vehicles have top speeds around 200 mph--to have a 20 mph increase in top speed a vehicle with 400 HP engine would need an additional 130 HP! Driving a Standard (or Manual) transmission. Many high performance cars, like older (before 1990) sports cars have manual transmissions. Also, cars with very low power output have manual transmission. For the sports cars, the owners are interested in the highest possible performance, and automatic transmissions, which contain "slush boxes" are not acceptable. The really small cars produce so little power in their engines that they cannot afford to waste any in the automatic transmission. Even a very well designed automatic will have about 5% losses due to the torque converter. Also, automatic transmissions are relatively heavier and more expensive compared to equivalent manual transmissions. The really high performance sports car being sold today have the automatic manual transmissions, which have the best of both worlds. Preparation. Before driving the car, make sure that you are able to sit in a comfortable position. Adjust the rear view mirrors so that you have a good field of vision. Depress the various pedals to make sure that you are comfortable with the operations necessary for driving the vehicle. Starting From Rest. Many manual transmissions have a hand brake (also called parking brake). When parked, they are secured by pressing the button and pulling the parking brake upwards until enough pressure is applied to secure the vehicle. If the vehicle is on a level road, starting is quite straightforward. Place your right leg above the brake pedal and press down just to be safe. You will have to apply a relatively large force because the power brakes depend on engine vacuum to work. Put the vehicle in neutral gear by depressing the clutch and moving the lever down to the neutral position. For a modern vehicle, you can start by turning the key, which will start the engine at idle speed. For older vehicles, you may need to depress the gas pedal when you start. For both cases, after the engine has started, slightly depress the gas pedal to increase engine speed and hold it there. Some sports cars such as the Porsche Carrera GT have variable idle speed, so that the idle speed increases as the clutch engages, which means that you can start the engine without depressing the accelerator at all. You should not race the engine, as it will cause a lot of damage, the only resistance to increase in the engine speed is the inertia of the small fly wheel. Release the clutch to the bite point, where the vehicle starts to move slightly forward. After this, release the clutch slowly and smoothly and this will move the vehicle forward. After the clutch has engaged fully, remove foot from the clutch. You should never drive the vehicle with foot resting on the clutch. Depress the accelerator some more to increase speed. Follow the same procedure, but with the reverse gear instead of the first gear for moving backwards from rest. Note however, that you will not be running with the clutch fully engaged in most cases since the speed will be too high for basic maneuvers. Starting on an Incline. Many times, you may be forced to park on a hill or incline. In this case, it is important that you be able to start the vehicle without it going backward, and potentially hitting someone behind you. There is a good way and two bad ways to do this. The first bad way is to use the handbrake to hold the car while you put your foot on the accelerator and the clutch pedal. Now press the accelerator slightly and hold it there, so that the engine is at a speed somewhat higher than idle speed. Release the clutch till it reaches bite point, and as you feel the car starting to move forward, release the handbrake. This still requires considerable skill, as the engine will stall if you don't release the handbrake in time. Further, it will not work in cars which don't have a handbrake (many manual transmissions don't). The second bad way is to put the vehicle in first gear and engaging the clutch fast enough while depressing the accelerator. The vehicle might not even move back if you do it fast enough. This can be done in places where you don't have any vehicles right behind you, and even if the vehicle moves back a little, you don't cause any damage. The good way to start a vehicle on an incline is to hold the vehicle on the incline using the foot brake and slowly release the clutch. When you feel the clutch reach the bite point, remove the foot quickly from the brake and depress the accelerator slightly. Note that if you engage the clutch fully, or very close to that, the engine will stall as it tries to work against the slope and the foot brake. So the ideal point for releasing the brake is at a very small point before the bite point. Now, the engine is at its idle speed, and cannot pull the vehicle up the slope if the clutch is engaged. Even if you engage the clutch slowly at this point, the engine will stall. You will have to depress the accelerator so that the engine speed (and the torque) increases. Now release the clutch smoothly, while releasing the accelerator slightly. If you release the clutch and don't release the accelerator, the vehicle will move forward with a larger speed than you want. If you have done everything right, the vehicle will move forward, and this works in all situations. The usual mistake in this procedure comes from the inability to judge the bite point. On level ground, you can feel the vehicle start to move forward when the clutch starts to engage. However, on the slope, this effect is quite subtle and is easily missed, as the brake prevents the vehicle from moving. If you release the clutch too much, the engine will stall. In that case, depress the clutch, shift to neutral and start the engine again. However, if you don't release the clutch enough when you remove your foot from the brake, then you will be in a lot of trouble. If the clutch has made "some" contact, then you can depress the accelerator a lot to increase the torque, and move the vehicle forward. However, note that when you do this, you will have to release the accelerator fast as the clutch engages or the vehicle will shoot forward. Also, when you engage the clutch at such high speeds and torques, there is a lot of wear. If you release the accelerator too much, the engine will stall. The other possibility is that the clutch hasn't engaged at all when you remove your foot from the brake. This is the worst result possible, as the vehicle will now move backward, possibly colliding with the vehicle behind you. In driving tests, the vehicle moving back is instant failure. Note that it is a very bad idea to hold the vehicle on an incline using the clutch, as it can cause rapid clutch wear. Stopping a Vehicle. Depress the brake slightly to slow the vehicle, and once a good amount of speed has been removed depress the clutch fully and apply brakes smoothly to stop the vehicle wherever you want. After the vehicle comes to a stop, put the vehicle in neutral without releasing the brake. Turn off the engine. Now depress the clutch and if it is a downhill slope put the vehicle in reverse. Otherwise, put it in first gear. Release the clutch, and only then release the brake. You can stop a vehicle from any gear, but remember not to run the vehicle with the clutch depressed for a long time as it can still cause clutch wear. If your vehicle has a handbrake, engage the hand brake now. Shifting to Higher Gears. Once you have successfully engaged the clutch in first gear, you should immediately increase speed and engage the second gear. You should never operate the vehicle only in the first gear. It is used for starting the movement of the car from a dead stop and low speeds under 15 mph constant speed. Also, never shift to first gear while the vehicle is moving. To engage the second gear, release the accelerator and depress the clutch fully. If you don't depress the clutch fully, you won't be able to move the shift lever in well designed cars. In many cars, no such fool proof method exists and the result will most likely be a sickening grinding sound of your transmission falling apart. Move the lever down smoothly to the center. It should automatically fall into the neutral position. Now move the lever to the left and then pull down. Release the clutch smoothly and after that is done, depress the accelerator to increase speed suitable for second gear. Your aim is to operate the vehicle at the highest gear possible considering the state of the road and traffic. Thus you should shift to the third gear as soon as possible, and this is as soon as your vehicle speed reaches the minimum value at which it can be driven in the third gear without stalling. To shift into third gear, release the accelerator and depress the clutch fully. Move the shift lever up slightly, and it will fall into the neutral position. In most passenger cars you can now move the lever up from here to the third gear position. However, some vehicles may have the neutral position midway between the first and third lever positions, so that you may need to move it slightly to the right to move it up to third. As you can imagine, it takes quite a lot of practice before you can shift to the third gear of such a vehicle, which makes it very difficult to drive. Hopefully, the market will eliminate such unfriendly designs. For a vehicle which has six gears, however, the standard H is necessarily different. For instance, the typical BMW shift has the reverse in the leftmost top position, with nothing vertically down. The six forward gears are arranged opposite each other in pairs, with the neutral between third and fourth. Now that you have moved the lever to the third gear position, release the clutch. Depress the accelerator to increase speed and move to the next higher gear. Moving to fourth gear is straightforward in almost all vehicles (even in the difficult ones mentioned earlier). Remove your foot from the accelerator, and depress the clutch fully. Pull the shift lever all the way down and this will move it to the fourth gear position. Now release the clutch and place your foot on the accelerator and increase the speed by depressing the accelerator. Most vehicles have five forward gears, and engaging the fifth gear (usually the overdrive gear) is not difficult. Remove your foot from the accelerator, and depress the clutch fully. Move the shift lever up from the fourth gear and it will fall into the neutral position. Now move it all the way to the right and move it up to the fifth gear position. Release the clutch and depress the accelerator to achieve the speed limit value for the road. Note that you should never skip a gear, in most situations. So what exactly happens when you carry out the instructions above? When you take your foot off the accelerator, the engine loses speed due to internal friction and tries to fall back into idle speed. By the time you complete the actions required to shift the gear position, the rpm of the engine has fallen a fair bit. This is good, because you need the engine rpm to decrease when you shift gears up. Thus, taking the foot of the accelerator for the duration achieves the ideal. This clears up the intent of the statement in the beginning of the paragraph. The idea is to reduce the engine rpm to an acceptable value while keeping the road speed up. The reduction in speed will not be possible with skipping gears on a level road. If you wait a long time, then the road speed will also decrease, so that it will not be greater than the minimum required for that gear. Thus, you cannot shift from third to fifth, say, under normal circumstances. Shifting to Lower Gears. The most fuel efficient setting to drive a vehicle is at the highest gear available. However, there are cases when you might shift to a lower gear. The most common is when you have to reduce speed due to road conditions or traffic. There are two common methods to shift down, and one is much simpler than the other. The common way to downshift to reduce speed is as follows. Remove foot from the accelerator and apply brake so that the speed of the vehicle reduces. Now depress the clutch fully and continue applying brakes till the desired speed is reached. Now release the brake and move the lever to the gear position appropriate for the speed. Release clutch slowly. Depress accelerator and continue. For instance, if you see that the vehicle in front is temporarily slowing down, you might want to shift down one gear, say, from fifth to fourth. However, if there is a major obstruction in the road, you might want to slow down to walking speed, and this requires engaging the clutch when in second gear. Remember that unlike shifting up, you can choose whatever gear you want when downshifting depending on the vehicle speed, except the first. Choose the first gear only if you have come to a complete stop. Double De-Clutching. Note that when you need to move to a lower gear, you want the engine to spin at a higher rpm than it is doing while in the higher gear. But if you have read the explanation of up shifting in the previous section, you will see that the engine speed will "fall" when you remove your foot from the accelerator. Now if you engage the clutch, the car will jerk as the engine tries to pick up speed. This is very hard on the synchro and the engine. The standard way to deal with this is to depress the accelerator while engaging the clutch slowly. However, this causes excessive clutch wear. The other method, which requires some skill, is called "double de-clutching". In this method, you take the foot off the accelerator, and depress the clutch fully. Then move the lever into the neutral position and release the clutch. Now depress the accelerator for a very short duration, which can be safely done as the clutch is engaged. Now release the accelerator and depress the clutch. Move the lever to the next lower gear, and the clutch can be engaged smoothly. Notice that you will be using the brake to slow the vehicle down, and this method requires you to take your foot off the brake to press the accelerator for a while. If you are braking because of some traffic trouble or an obstruction on the road, you may not want to do this. Also, this causes a sudden change in the forces applied on the vehicle, and it can affect the contact between the tire and the surface. Ideally, all the actions in the vehicles must be smooth, and you should avoid sudden acceleration, braking, steering adjustment etc. One way to avoid taking your foot off the brake is the so called "heel and toe" method. In this method, you apply brakes to slow the car down, and then depress the accelerator with your heel while keeping your toe on the brake when the gear position is in neutral. As you can imagine, doing so without changing the pressure on the brake pedal requires a lot of practice, but once done right, it is the best method. When to Downshift? While the primary reason for downshifting is to reduce speed, there are other situations where it is useful. You get higher torque in lower gears, and you may want to shift down when facing a hill, if you want to avoid a stall. Another is when you want to overtake a vehicle quickly. You can get much more power when overtaking in, say, the fourth gear rather than the fifth gear if the vehicle has a 5 speed transmission. However, remember that the engine will red line (above recommended "rotations per minute of the crankshaft" which is referred too as "RPM") at much lower speeds in lower gears. Fuel Efficiency. The manual transmission is very efficient in terms of power transfer in that it doesn't have the fixed 5% loss in automatics. However, another reason many prefer manual transmissions is that it places a lot of control in the hands of the driver. While climbing a hill, you use a lower gear, since it will have larger torque available. However, once at the top, you can shift to neutral and turn off the engine, and roll down the hill. At the foot of the hill, depending on the speed you can shift to the appropriate gear. Note that the above may not be possible on many modern computer controlled cars, where shutting off the engine may lead to damage many of the running parts, and locking of the steering wheel. Power Band. The power band is the range of engine rpm where it produces good power output and this is between the torque peak and the power peak. In fact, the whole purpose of the gear box is to make sure that the engine works inside the power band at all times. Consider a vehicle going up a hill--as it moves up from level ground, the slope will cause and increased load against which the wheels have to work. If the engine is already in the power band, the reduction in speed will increase the torque (as it is beyond the torque peak), and you won't have to shift down. On the other hand, if the engine is not in the power band, the uphill motion will cause the RPM and torque to fall, requiring a quick down shift. If you enter a slope with the engine already lugging (too slow (low rpm)for that gear), you may have to double de-clutch (modern cars have synchronisers in all gears for upshifts and downshifts except reverse) rapidly to a lower gear or a gear two positions lower. For instance, if you approach a hill at the lower limit of your fourth gear, shifting down to third may not help due to the loss of momentum due to the slope of the hill. You will need to double de-clutch into second gear and then accelerate into third. Braking. When you encounter an obstacle in the road and want to slow down, you will do so by first removing your foot from the accelerator and allowing the vehicle to slow down before applying the brake. It is a good idea to give the driver behind you a warning in this occasion by blipping the brake. After the vehicle has slowed down a bit (engine braking), apply brakes slowly to reduce speed, and then depress clutch fully and slow down further by braking smoothly. Now you can switch to the appropriate lower gear and remove your foot from the brake. One place where need for braking is not so obvious is while coming down a speed breaker. If you don't break when the rear wheel moves down the speed breaker, the rear end of your car will strike the ground, especially if it has a large overhang at the rear. So the procedure should be--brake well before the obstacle to make sure that your front is clear of it as the nose dips due to braking, then move smoothly up, making sure you have enough momentum to carry you through (very bad idea to have to rev your engine on a slope), and then when the rear wheel comes off the obstacle reduce the speed even further by smooth braking. Should you use engine braking? Well, engine braking still acts through the wheels, so there is no great improvement in road handling. However, if you are travelling downhill, engine braking is recommended (and is the preferred method) as using the brake pedal will cause overheating and failure of the brake pads. Another use for engine braking is if you need to come to a stop rapidly. That is, if you have a vehicle suddenly stop before you, or you have a pedestrian jump in front, and you must absolutely stop the vehicle. Here you can switch to the lower gear rapidly (say from the 5th to the 2nd), and use the engine for braking along with the brake pads. Thus, if you have mastered rapid downshifting, you can bring the car to a stop using this method by using all the gears from 5th down to 2nd, instead of skipping gears. This will definitely cause engine damage, but is preferable to loss of life (either to you or the other people on the road). The usual method to use engine braking is to switch to a lower gear for this purpose. The stopping distance in braking is roughly proportional to the square of the speed of the vehicle. Thus, you will need twice the stopping distance at 40 mph compared to 30 mph. The stopping distance also depends on the road conditions (whether it is wet, the road is sealed) and the condition of the tires. It is very important that you maintain adequate distance between your vehicle and the vehicles in front of you as well as the vehicles behind you. You should reduce speed and increase the distance in wet conditions, for instance. Engine Damage. If you follow the safe and recommended practices while using your car, your engine will last a long time. Note that the engine should not be raced (high rpm at low loads) or loaded at low rpm. It is easy to get feedback on high rpm--the engine noise increases as speed increases. However, low rpm loading, where you open the throttle at high gear when the rpm is low, is not as easy to detect. If you find yourself depressing the accelerator pedal too much at high gear, shift down to a lower gear to bring the engine speed up. Always be aware of the speed of your vehicle as you drive, and as soon as it drops, shift the gear down, this might result in more gear shifts, and that is all the more reason to choose a vehicle with a good gear box. You don't usually have much choice in the kind of roads that you drive on, but try to use level roads as far as possible. Also, make sure that your driveway is flat and if it is at a higher level than the road, then make sure that the incline is closer to the road than the final parking position. Remember the warning about low rpms and high loads. A sure fire way to severe engine damage is an inclined driveway, which you drive up everyday at low speeds. If you look at the load on the bore due to the dynamics of the crank motion of the piston and crankshaft assembly you will find that force acts on one side of the cylinder. Now, a properly designed engine will have the combustion forces act in such a way as to cancel this effect. Driving Test. You will need a license to drive a vehicle in any country in the world. The specifics of tests will differ, but the general idea is to demonstrate your ability to handle the class of vehicle for which you are applying for a license. A commercial license (to drive trucks, say) will have much more stringent requirements compared to a consumer license (such as for automobiles). There might be additional restrictions too--for instance, in many countries you cannot obtain a license to drive a manual transmission if you take the test on an automatic. The test consists of a written exam to test your knowledge of rules specific to the country/area as well as general rules, and a hands on test where you drive the vehicle in traffic as well as some specific maneuvers that you are required to perform. Also, you might be asked to negotiate some configurations (like the "standard 8"). The maneuvers might include, among other, parallel parking, and starting on an incline. Parallel Parking. Parallel parking is used to park a car on the side of a road, between two parked vehicles. Some of the newer cars (e.g. the ) have automatic parallel parking, where it is done by the onboard computer. Driving Terrain and Obstructions. When you come across a road with pot holes in it, apart from slowing down, make sure that only one wheel goes into the pothole. Of course, it would be even better if you could avoid it altogether, but sometimes that is not possible. Sometimes you may have to stop at a speed breaker--a good idea would be to straddle your vehicle across it, if you cannot go past it altogether before stopping. When you start, you can engage the clutch without revving the engine and then use the momentum to carry you over the obstruction. Sometimes you get into a hole which you cannot climb out of even with a lot of revving. In this case you should unload your passenger and rock your vehicle using the first and reverse gears in sequence, building up amplitude as you would do with a swing. Do not do this for more than a minute or two as you can easily damage the engine. If rocking fails, you can try jacking the vehicle up, and filling the hole with some material from the road. Low End Performance. Many cars are not driven on highways, but within the city. While automobile manufacturers like to quote highway fuel efficiency and performance for their cars, many vehicles will spend most of their fuel in the city. As was mentioned earlier, the key to fuel efficiency is to run the vehicle at as high a gear as possible without lugging. This can be done by extending the power band to the low rpm range. One way to do this is by way of an exhaust chamber tuned for low end performance. Using resonance, it is possible to reduce the back pressure from the exhaust gases, so that the breathing of the engine is better even at lower speeds. A hot rod method to increase low end torque is to use a water spray to cool the exhaust, which will reduce its pressure, leading to better engine breathing. A big design issue is to prevent entry of moisture into the combustion chamber. This kind of mechanism was used in the earlier heavy transport aircraft during take off. Links. Free driving test video tutorials, tips and information Free Driving Theory Test Software

Amateur Radio Manual/Sources of Current. We can make electrons move in a conductor by supplying energy. If we apply the energy equally, for instance, by heating it, the electrons will move randomly from atom to atom. This isn't very useful to us. We want to be able to control the direction and flow of the electrons. We can accomplish this by attaching a negative source to one end of our conductor and a positive source to the other end. We have just created a circuit. The electrons will flow from the negative end to the positive end. As we stated earlier, heat is one method of causing electrons to flow. We can also do this by using friction, pressure (some crystals will create electron flow under pressure see piezoelectric effect), magnetism, photoelectric effect, and chemical reactions. Chemical reactions are perhaps the most common source of direct current, better known as a cell or battery. A battery usually consists of two conductors, or electrodes, placed in an electrolyte or the chemicals responsible for reacting and producing current flow. There are a large number of different types of batteries. The common carbon-zinc flashlight battery is an example of a primary cell, that is a battery that cannot be recharged. The lead acid car battery is an example of a secondary cell, or a cell that can be recharged. Be cautious with alkaline batteries, some are primary and some are secondary types. Attempting to recharge a primary battery can be dangerous especially if the heat built up inside the cell causes it to explode. Common Cells

Primary Mathematics/Numbers. Numbers. This section is for students to read by themselves or with the help of a teacher or parent. Natural Numbers. When we count apples or oranges or elephants, we are using natural numbers. Natural numbers are 1, 2, 3, and so on without end. There is no largest natural number; one can always get a larger natural number by adding 1 to the previous number. Zero. Zero represents nothingness. Zero is less than every natural number. If we have zero apples or oranges or elephants, we simply do not have anything. Teaching Numbers. This section is for teachers or home-schoolers. It is about teaching the basic concepts and conventions of numbers. Developing a sound concept of number. Children typically learn about numbers at a very young age by learning the sequence of words, "one, two, three, four, five" etc. Usually, in chanting this in conjunction with pointing at a set of toys, or mounting a flight of steps for example. Typically, "mistakes" are made. Toys or steps are missed or counted twice, or a mistake is made in the chanted sequence. Very often, from these sorts of activities (and from informal matching activities), a child's concepts of numbers and counting emerge as their mistakes are corrected. However, here, at the very foundation of numerical concepts, children are often left to "put it all together" themselves, and some start off on a shaky foundation. Number concepts can be deliberately developed by suitable activities. The first one of these is object matching. Matching Activities. As opposed to the typical counting activity children are first exposed to, matching sets of objects gives them a solid foundation for the concepts of numbers and numerical relationships. It is very important that matching should be a "physical" activity that children can relate to and build on. Typical activities would be a toy's tea-party. With a set of (say) four toy characters, each toy has a place to sit. Each toy has a cup, maybe a saucer, a plate etc. Without even mentioning "four", we can talk with the child about "the right number" of cups, of plates etc. We can talk about "too many" or "not enough". Here, we are talking about number and important number relations without even mentioning which number we are talking about! Only after a lot of activities of this type should we talk about specific numbers and the idea of number in the abstract. Number and Numerals. Teachers should print these numbers or show the children these numbers. Ideally, the numbers should be handled by the student. There are a number of ways to achieve this: cut out numerals from heavy card stock, shape them with clay together, purchase wooden numerals or give them sandpaper numerals to trace. Simultaneously, show the definitions of these numbers as containers or discrete quantities (using boxes and small balls, e.g., 1 ball, 2 balls, etc. Note that 0 means "no balls"). This should take some time to learn thoroughly (depending on the student). 0 1 2 3 4 5 6 7 8 9 Place Value. The Next step is to learn the place value of numbers. As you are aware, the number after 9 is 10 (called ten). This number is represented by a new place, the tens, and each time the number in the second place value increases, represents a collection of ten units. After this comes the hundred place, followed by thousands. Even though numbers can be much bigger, we will not need to create larger numbers at this time. To help visualization, you can represent 10 as a bag of 10 coins, and 100 as a box filled with 10 such bags. Place Values in other number systems. Other number systems are not the same as the one we currently use. For example, the Maya Culture where there are not the ten symbols above but twenty symbols. Even though there are more symbols, the place value system still remains intact. A common number system used with computers is the use of binary, which uses the two symbols 0 and 1. Here is how the system will be created: If one uses the symbols A and B, you can get: Trinary, which uses three digits, is also possible: These external websites may give you enough information to figure the place value idea of any number system.