title
stringlengths 1
149
⌀ | section
stringlengths 1
1.9k
⌀ | text
stringlengths 13
73.5k
|
|---|---|---|
Nissan RD engine | Nissan RD engine | Since the Nissan RD engine is based on the Nissan RB engine, they have many similarities and many parts are interchangeable. The engine block was similar to the RB30 engine except it had more material, was heavier and had 85mm bore vs the 86mm bore of the RB30 and a 83mm stroke vs 85mm stroke. One issue is that the stronger vibrations from the diesel engine can loosen the crank/harmonic balancer bolt (originally from the RB engines) and in turn become loose or fall off causing major engine damage. It is recommended to use thread locking fluid when installing. The cylinder head was of a non-crossflow design, meaning that the exhaust and intake ports were on one side of the cylinder head. |
Nissan RD engine | RD28 | 2.8 L (2,826 cc) SOHC, 85 mm (3.35 in) bore RD28 Series 1 12 valves (two per cylinder). When originally introduced, JIS gross were used rather than JIS net, meaning that early information claims 100 PS (74 kW; 99 bhp) and 18.5 kg⋅m (181 N⋅m; 134 lb⋅ft) at the same engine speeds.94 PS (69 kW; 93 bhp) at 4,800 rpm18 kg⋅m (177 N⋅m; 130 lb⋅ft) at 2,400 rpm Nissan Skyline R31 series 1985–1987 Nissan Laurel C32 ~ C34 series 1986–1993 Nissan Cedric / Nissan Gloria Y30 ~ Y32 series 1985–1993 Commercial (taxi) Nissan Cedric / Nissan Gloria Y31 series sedan 1987–1999 Nissan Crew K30 series 1993–1999 Nissan Cefiro A31 series 1988–1993No PCV on the tappet cover. |
Nissan RD engine | RD28 | RD28 Series 2 100 PS (74 kW; 99 bhp) at 4,800 rpm18.2 kg⋅m (178 N⋅m; 132 lb⋅ft) at 2,400 rpm Nissan Cedric / Nissan Gloria Y32 & Y33 series 1993–1999 Nissan Laurel C34 - C35 series 1994–1999 RD28E 100 PS (74 kW; 99 bhp) at 4,800 rpm18.2 kg⋅m (178 N⋅m; 132 lb⋅ft) at 2,400 rpm Commercial (taxi) Nissan Cedric Y31 series sedan 1999.08-2002 Nissan Laurel C35 series 1999–2001 Nissan Crew K30 series 1999-2009Vacuum pump located on tappet cover. |
Nissan RD engine | RD28T | 2.8 L (2,826 cc) SOHC turbodiesel125 PS (92 kW; 123 bhp) at 4,400 rpm26 kg⋅m (255 N⋅m; 188 lb⋅ft) at 2,400 rpm Nissan Safari Spirit series Y60 2-door soft-top 1996–1997 Nissan Civilian Bus RD28ETi1 electronically controlled turbodiesel with an intercooler135 PS (99 kW; 133 bhp) at 4,000 rpm29.3 kg⋅m (287 N⋅m; 212 lb⋅ft) at 2,000 rpm Nissan Safari Spirit series Y61 2-door soft-top 1997–1999 (automatic transmission) RD28ETi2 electronically controlled turbodiesel with an intercooler145 PS (107 kW; 143 bhp) at 4,000 rpm26.6 kg⋅m (261 N⋅m; 192 lb⋅ft) at 2,000 rpm |
Arch Linux ARM | Arch Linux ARM | Arch Linux ARM is a port of Arch Linux for ARM processors. Its design philosophy is "simplicity and full control to the end user," and like its parent operating system Arch Linux, aims to be very Unix-like. This goal of minimalism and complete user control, however, can make it difficult for Linux beginners as it requires more knowledge of and responsibility for the operating system. |
Arch Linux ARM | History and development | Arch Linux ARM is based on Arch Linux, which is a minimalist Linux distribution first released on March 11, 2002. The idea of making a single, official port of Arch Linux for devices with ARM processors was born from members of the Arch Linux PlugApps and ArchMobile development teams, notably Mike Staszel, who went on to found the Arch Linux ARM project.Kevin Mihelich is currently Arch Linux ARM's primary developer. Arch Linux ARM is community-developed, with software development and user support provided fully by volunteer effort and donations. Also, unlike other community-supported operating systems such as Ubuntu, Arch Linux ARM has a relatively small user base, making user participation in development especially important.Arch Linux ARM has a rolling release cycle, i.e. new software is packaged as it is released. This "bleeding edge" release cycle of small, frequent package updates differs from release cycles of Linux distributions such as Debian, which focus on large, scheduled releases of packages proven to be stable. |
Arch Linux ARM | Supported processors | Unlike Arch Linux, which is aimed at x86-64 CPUs, Arch Linux ARM targets ARM CPUs and, as a result, many single-board computers such as the Raspberry Pi.There is support for: ARMv7 1st generation Cortex-A8 platforms, such as the BeagleBoard or Cubieboard ARMv7 2nd generation Cortex-A9 and Tegra platforms, such as the PandaBoard or TrimSlice ARMv7 3rd generation Cortex-A7 and Cortex-A15 platforms, such as the Cubieboard2, Odroid XU, Samsung Chromebook (series 3), Samsung Chromebook 2 or Raspberry Pi 2 ARMv8 64-bit capable Cortex-A53 and Cortex-A72 platforms, such as the Odroid C2 and N2, Acer Chromebook R13 or Raspberry Pi 3.Arch Linux ARM can run on any device that supports ARMv7 or ARMv8 instruction sets, including the 64-bit ARMv8 instruction set of the Raspberry Pi 3 and 4.For a list of officially supported platforms, see archlinuxarm.org's Platforms page. For a list of unofficial, community-supported devices, see archlinuxarm.org's Community-Supported Devices forum. |
Arch Linux ARM | Reception | Arch Linux ARM has gained popularity as a lightweight Linux distribution, and in 2014 was growing in popularity among single-board computer hobbyists. Arch Linux ARM is also known for having good community support. In 2021-2022, The Asahi Linux Project used a tailored version of Arch Linux ARM with the use of special imaging requirements, scripts, and other utilities to get the Apple Hardware correctly read by the operating system, ultimately however, the project was moved to use Fedora’s OSes following problems in dependencies, slow response times when requesting support on the manner, and other issues. |
Tropical green building | Tropical green building | Tropical Green Building refers to a style of construction that focuses on energy reduction, reduced use of chemicals, and supporting local labor and community. This requires close cooperation of the design team, the architects, the engineers, and the client at all project stages, from site selection, scheme formation, material selection and procurement, to project implementation. Tropical Green Building has the same basis as green building in more temperate climates, but the methods of construction are completely different. In the tropics, the focus is on keeping cool, preventing insect infestations, and reduced mould, damp and maintenance in the home. |
Tropical green building | Tropical green building | Generally, tropical green building also seeks to reduce power consumption through intelligent architecture, such as by allowing in much natural light so electric lights aren't needed during the daytime, and at night, using white-painted roofs, ceilings and low-energy light bulbs such as compact fluorescents or LED lamps.
Solar power, wind power, and/or the use of micro hydro are often deployed, but not always the focus of tropical green building. |
Tribsoft | Tribsoft | Tribsoft was a Canadian software company that specialized in porting computer games to the Linux platform. |
Tribsoft | Tribsoft | It was responsible for porting Jagged Alliance 2, as well as gaining the porting rights to Europa Universalis, Majesty: The Fantasy Kingdom Sim and Jagged Alliance 2: Unfinished Business. In the end only Majesty was ever ported and that was done by Linux Game Publishing. Europa Universalis II was also said to be coming to Linux.Sometime in 2002 the owner of Tribsoft mentioned that he was "taking a short break" from porting games to Linux. This break eventually became permanent, when Tribsoft shut down in late 2002. |
Spore-like cell | Spore-like cell | Spore-like cells were proposed to be pluripotent cells that lie dormant in animal tissue and become active under stress or injury as adult stem cells, exhibiting behavior characteristic of spores. They were proposed in 2001 by brothers Charles and Martin Vacanti and colleagues. Further work in collaboration with Japanese researchers led to the apparent discovery of STAP cells, in which the pluripotent cells were newly created by stress or injury. This work was published in 2014, but soon found to be due to fraudulent work by Haruko Obokata. |
Spore-like cell | Characteristics | Spore-like cells were said to be a specific class of stem cells in adult organisms, including humans, which are small, versatile, and most frequently remain in a dormant "spore-like" state as the rest of the cells of the organism divide, grow, and die. Despite their dormancy, they apparently retain the ability to grow, divide, and differentiate into other cell types expressing characteristics appropriate to the tissue environment from which they were initially isolated, if some external stimulus should prompt them to do so. This capacity to continue to regenerate new cells has been shown in in vitro conditions for some animals in which all other cells have died, especially if the animal died from exposure to cold elements. |
Spore-like cell | Characteristics | Spore-like cells were said to remain viable in unprepared tissue (using no special preservation techniques), frozen at -86 °C and then thawed, or heated to 85 °C for more than 30 minutes. This has led researchers to try to revitalize spore-like cells from tissue samples of frozen carcasses deposited in permafrost for decades (frozen walrus meat more than 100 years old, and mammoth and bison in Alaska estimated to be 50,000 years old). Vacanti et al. believed that these unique cells lie dormant until activated by injury or disease, and that they have the potential to regenerate tissues lost to disease or damage. Because the cell-size of less than 5 micrometers seems rather small as to contain the entire human genome the authors speculate on the "concept of a minimal genome" for these cells. |
Spore-like cell | Later work | Charles Vacanti continued to work on these cells when he moved to Harvard, including with thoracic surgeon Koji Kojima who identified them in lung tissue. Working with a graduate student Haruko Obokata in his lab at Harvard from 2008, Vacanti later refined this theory to suggest that stress or injury could actually trigger the development of pluripotency in somatic cells. He first proposed this to Obokata and Masayuki Yamato at a conference in Florida in 2010; Yamato had independently come to the same conclusion. Obokata returned to Japan and continued this work at RIKEN. Vacanti presented these results in July 2012 at the Society of Cardiovascular Anesthesiologists conference, and then in January 2014 the journal Nature published two articles suggesting that a simple acid treatment could cause mouse blood cells to become pluripotent. The Boston Globe reported that "His discovery is a reminder that as specialized as science is, sometimes, a little ignorance may be a virtue. A stem-cell expert would probably never have even bothered to try the experiment Vacanti has been pursuing, on and off, since the late 1990s." Both STAP articles were retracted in July 2014 after an investigation by RIKEN concluded that the data were fabricated.Researcher Mariusz Ratajczak has linked spore-like cells to his idea of Very small embryonic-like stem cells, also proposed to be very small adult stem cells. |
Bicategory | Bicategory | In mathematics, a bicategory (or a weak 2-category) is a concept in category theory used to extend the notion of category to handle the cases where the composition of morphisms is not (strictly) associative, but only associative up to an isomorphism. The notion was introduced in 1967 by Jean Bénabou.
Bicategories may be considered as a weakening of the definition of 2-categories. A similar process for 3-categories leads to tricategories, and more generally to weak n-categories for n-categories. |
Bicategory | Definition | Formally, a bicategory B consists of: objects a, b, ... called 0-cells; morphisms f, g, ... with fixed source and target objects called 1-cells; "morphisms between morphisms" ρ, σ, ... with fixed source and target morphisms (which should have themselves the same source and the same target), called 2-cells;with some more structure: given two objects a and b there is a category B(a, b) whose objects are the 1-cells and morphisms are the 2-cells. The composition in this category is called vertical composition; given three objects a, b and c, there is a bifunctor ∗:B(b,c)×B(a,b)→B(a,c) called horizontal composition.The horizontal composition is required to be associative up to a natural isomorphism α between morphisms h∗(g∗f) and (h∗g)∗f . Some more coherence axioms, similar to those needed for monoidal categories, are moreover required to hold: a monoidal category is the same as a bicategory with one 0-cell. |
Bicategory | Example: Boolean monoidal category | Consider a simple monoidal category, such as the monoidal preorder Bool based on the monoid M = ({T, F}, ∧, T). As a category this is presented with two objects {T, F} and single morphism g: F → T.
We can reinterpret this monoid as a bicategory with a single object x (one 0-cell); this construction is analogous to construction of a small category from a monoid. The objects {T, F} become morphisms, and the morphism g becomes a natural transformation (forming a functor category for the single hom-category B(x, x)). |
Embryokine | Embryokine | Embryokines (Greek: embryuon "embryo" + kinōs "movement") are regulatory molecules produced by the oviduct and endometrium in the reproductive tract that modulate embryonic growth and development.Embryokines include growth factors such as insulin-like growth factor-1, and activin a transforming growth factor; cytokines such as colony stimulating factor 2, WNT regulatory proteins including DKK1; Other small molecule amino acids are included that regulate embryonic development through the mTOR signalling pathway. Prostacyclin 1 can activate peroxisome proliferator-activated receptor 6 to increase blastocyst hatching, and cannabinoids that can also act to regulate implantation and development. |
SARS-CoV-2 in mink | SARS-CoV-2 in mink | Both the American mink and the European mink have shown high susceptibility to SARS-CoV-2 since the earliest stages of the COVID-19 pandemic, first in mink farms across Europe, followed by mink farms in the United States. Mortality has been extremely high among mink, with 35–55% of infected adult animals dying from COVID-19 in a study of farmed mink in the U.S. state of Utah.In November 2020, in Denmark, it was announced that all mink nationwide were being slaughtered due to reports that a mutated SARS-CoV-2 virus was being passed from mink to humans via mink farms, and that at least 12 human infections had been discovered in Northern Jutland. While the State Serum Institute (SSI, Statens Serum Institut) suggested that this mutation was no more dangerous than other coronaviruses, SSI head Kåre Mølbak warned that the mutation could impact the development and effectiveness of COVID-19 vaccines.The first known transmission of SARS-CoV-2 among wild mink was reported in Utah, which researchers believed was due to contact with infected captive mink rather than through an intermediary vector in the wild or direct human-to-mink transmission. Tracking the origin and spread of mink-related COVID variants has proven more difficult in the United States, where the reporting of outbreaks on mink farms has been voluntary, as opposed to the mandatory screening procedures introduced during outbreaks in Denmark and the Netherlands. |
SARS-CoV-2 in mink | Transmission | Due to the mink ACE2 receptor being a similar or better fit for SARS-CoV-2 compared to humans and the cramped living conditions of farm-raised animals, mink readily transmit SARS-CoV-2 to one another and develop symptoms of COVID-19. Additionally, Dutch researchers determined that the bedding materials and airborne dust on mink farms with outbreaks had also become highly contaminated. |
SARS-CoV-2 in mink | Mutations and variants | In Denmark, there have been five clusters of mink variants of SARS-CoV-2; the Danish State Serum Institute (SSI) has designated these as clusters 1–5 (Danish: cluster 1–5). In Cluster 5, also referred to as ΔFVI‑spike by the SSI, several different mutations in the spike protein of the virus have been confirmed. The specific mutations include 69–70deltaHV (a deletion of the histidine and valine residues at the 69th and 70th position in the protein), Y453F (a change from tyrosine to phenylalanine at position 453, inside the spike protein's receptor-binding domain), I692V (isoleucine to valine at position 692), M1229I (methionine to isoleucine at position 1229), and a non-conservative substitution S1147L.In North America, a mink-human spillover event in Michigan, resulting in four human infections that were largely kept from public view upon their discovery late 2020, and only announced by the US Centers for Disease Control (CDC) in March 2021, was deemed ancestral to the Ontario WTD clade spillover event from white-tailed deer nearly a year later in Ontario, Canada. The Michigan spillback into humans was the first documented case of any animal spillback in the United States.In late 2022, scientists continued to monitor residual Delta strains, such as Delta strain AY.103, which have picked up Omicron mutations during co-infection in mink and deer and form the potential for so-called "Deltacron" spillover events. These hybrid strains could potentially combine the increased fatality rate of Delta with the enhanced transmissibility of Omicron. |
Shakes (timber) | Shakes (timber) | Shakes are cracks in timber. Arising in cut timber they generally cause a reduction in strength. When found in a log they can result in a significant amount of waste, when a log is converted to lumber. Apart from heart shakes, often found in trees felled past their best, shakes in a log have no effect on the strength of shake free lumber obtained therefrom.They are often seen in oak-framed buildings, which are constructed of oak which has not been dried and thus cracks while drying. Due to the immense strength of the oak beams, they are not a cause for concern in a properly engineered building, and are considered part of the charm of the style. |
Shakes (timber) | Shakes (timber) | In the majority of cases of shake, the underlying cause is a weakening of the wood due to action by anaerobic bacteria which have entered the tree stem through the root system. researchers have isolated anaerobic and facultative anaerobic bacteria from shake surfaces, in particular the anaerobes "Clostridiu" Research suggests that shakes develop due to natural stresses in wood which has been weakened by bacterial degradation of the middle-lamella between cells. |
Shakes (timber) | Heart shake | Heart shake is a crack in the heartwood, near the centre of the tree. It is caused by poor seasoning, or by using trees felled past maturity. |
Shakes (timber) | Star shake | A crack or cracks propagating from near the edge of the log towards the centre, usually along the line of the medullary rays, causing the wood to shrink more at right angles to the medullary rays than along them, causing warping of anything made from the wood. The cause is often rapid or uneven seasoning, causing the outside of the log to shrink faster than the heart. Exposure to the elements can cause star shakes, as can frost during the growth of the tree. |
Shakes (timber) | Frost shake | Frost shake begins on the outside where moisture from rain or other means has penetrated, and freezes, causing damage to the wood on the inside. |
Shakes (timber) | Cup or ring shake | A cup or ring shake follows the line of annual rings. The separation of the rings is generally caused during the growth of the tree, either by a check in the growth, or by bending and twisting under high winds. |
Shakes (timber) | Thunder shake or upset | Thunder shake is across the grain, and hard to detect until the boards are being planed. It is caused by shock to the wood, such as thunder, or concussion during felling. This fault seriously weakens the timber. |
Richard Vuduc | Richard Vuduc | Richard Vuduc is a tenured professor of computer science at the Georgia Institute of Technology. His research lab, The HPC Garage, studies high-performance computing, scientific computing, parallel algorithms, modeling, and engineering. He is a member of the Association for Computing Machinery (ACM). As of 2022, Vuduc serves as Vice President of the SIAM Activity Group on Supercomputing. He has co-authored over 200 articles in peer-reviewed journals and conferences. |
Richard Vuduc | Education | Dr. Vuduc received his Ph.D. in computer science from the University of California, Berkeley, in 2004. He received his B.S in computer science at Cornell University in 1997. He is also an alumnus of the Thomas Jefferson High School for Science and Technology in Alexandria, Virginia. |
Richard Vuduc | Academic career | Vuduc was a Postdoctoral Scholar in the Center for Advanced Scientific Computing at the Lawrence Livermore National Laboratory. He has served as an associate editor of both the International Journal of High-Performance Computing Applications and IEEE Transactions on Parallel and Distributed Systems. He co-chaired the Technical Papers Program of the “Supercomputing” (SC) Conference in 2016 and was later elected to be Vice President of the SIAM Activity Group on Supercomputing from 2016 to 2018. He also served as department’s Associate Chair and Director of its graduate (MS & Ph.D.) programs from 2013-2016. |
Richard Vuduc | Major honors and awards | Member of the DARPA Computer Science Study Group Recipient NSF CAREER award Collaborative Gordon Bell Prize 2010 Lockheed-Martin Aeronautics Company Dean’s Award for Teaching Excellence 2013 Best Paper Awards, including the SIAM Conference on Data Mining (SDM, 2012) and IEEE Parallel and Distributed Processing Symposium (IPDPS, 2015) |
Richard Vuduc | Major publications | Williams, Samuel; Oliker, Leonid; Vuduc, Richard; Shalf, John; Yelick, Katherine; Demmel, James (2007). "Optimization of sparse matrix-vector multiplication on emerging multicore platforms". Proceedings of the 2007 ACM/IEEE conference on Supercomputing - SC '07. p. 1. doi:10.1145/1362622.1362674. ISBN 9781595937643. S2CID 1845814.
Vuduc, Richard; Demmel, James W.; Yelick, Katherine A. (2005). "OSKI: A library of automatically tuned sparse matrix kernels". Journal of Physics: Conference Series. 16 (1): 521. Bibcode:2005JPhCS..16..521V. doi:10.1088/1742-6596/16/1/071. ISSN 1742-6596.
Vuduc, Richard (Rich). "Model-driven autotuning of sparse matrix-vector multiply on GPUs". ACM SIGPLAN Notices.
Im, Eun-Jin; Yelick, Katherine; Vuduc, Richard (February 2004). "Sparsity: Optimization Framework for Sparse Matrix Kernels". Int. J. High Perform. Comput. Appl. 18 (1): 135–158. CiteSeerX 10.1.1.137.5844. doi:10.1177/1094342004041296. ISSN 1094-3420. S2CID 2447843.
Vuduc, Richard Wilson (2003). Automatic Performance Tuning of Sparse Matrix Kernels (Thesis). University of California, Berkeley.
Demmel, J.; Dongarra, J.; Eijkhout, V.; Fuentes, E.; Petitet, A.; Vuduc, R.; Whaley, R. C.; Yelick, K. (February 2005). "Self-Adapting Linear Algebra Algorithms and Software". Proceedings of the IEEE. 93 (2): 293–312. CiteSeerX 10.1.1.108.7568. doi:10.1109/JPROC.2004.840848. ISSN 0018-9219. S2CID 3065125.
Vuduc, Richard; Demmel, James W.; Yelick, Katherine A.; Kamil, Shoaib; Nishtala, Rajesh; Lee, Benjamin (2002). "Performance Optimizations and Bounds for Sparse Matrix-vector Multiply". Proceedings of the 2002 ACM/IEEE Conference on Supercomputing. SC '02. Los Alamitos, CA, USA: IEEE Computer Society Press. pp. 1–35.
Lashuk, Ilya; Chandramowlishwaran, Aparna; Langston, Harper; Nguyen, Tuan-Anh; Sampath, Rahul; Shringarpure, Aashay; Vuduc, Richard; Ying, Lexing; Zorin, Denis (May 2012). "A Massively Parallel Adaptive Fast Multipole Method on Heterogeneous Architectures". Communications of the ACM. 55 (5): 101–109. doi:10.1145/2160718.2160740. ISSN 0001-0782. S2CID 2272736.
Rahimian, Abtin; Lashuk, Ilya; Veerapaneni, Shravan; Chandramowlishwaran, Aparna; Malhotra, Dhairya; Moon, Logan; Sampath, Rahul; Shringarpure, Aashay; Vetter, Jeffrey; Vuduc, Richard; Zorin, Denis; Biros, George (2010). "Petascale Direct Numerical Simulation of Blood Flow on 200K Cores and Heterogeneous Architectures". 2010 ACM/IEEE International Conference for High Performance Computing, Networking, Storage and Analysis. pp. 1–11. doi:10.1109/SC.2010.42. ISBN 9781424475599. S2CID 5490197.
Sim, Jaewoong; Dasgupta, Aniruddha; Kim, Hyesoon; Vuduc, Richard (2012). "A performance analysis framework for identifying potential benefits in GPGPU applications". Proceedings of the 17th ACM SIGPLAN symposium on Principles and Practice of Parallel Programming - PPoPP '12. p. 11. CiteSeerX 10.1.1.226.3542. doi:10.1145/2145816.2145819. ISBN 9781450311601. S2CID 6817445.
Vuduc, Richard; Chandramowlishwaran, Aparna; Choi, Jee; Guney, Murat; Shringarpure, Aashay (2010). "On the Limits of GPU Acceleration". Proceedings of the 2nd USENIX Conference on Hot Topics in Parallelism. HotPar'10. Berkeley, CA, USA: USENIX Association. p. 13.
Vuduc, Richard W.; Moon, Hyun-Jin (2005). "Fast Sparse Matrix-Vector Multiplication by Exploiting Variable Block Structure". High Performance Computing and Communications. Lecture Notes in Computer Science. Vol. 3726. Berlin, Heidelberg: Springer-Verlag. pp. 807–816. doi:10.1007/11557654_91. ISBN 978-3540290315.
Park, Sangmin; Vuduc, Richard W.; Harrold, Mary Jean (2010). "Falcon". Proceedings of the 32nd ACM/IEEE International Conference on Software Engineering - ICSE '10. Vol. 1. p. 245. doi:10.1145/1806799.1806838. ISBN 9781605587196. S2CID 8744239.
Vuduc, Richard; Demmel, James W.; Bilmes, Jeff A. (February 2004). "Statistical Models for Empirical Search-Based Performance Tuning". The International Journal of High Performance Computing Applications. 18 (1): 65–94. CiteSeerX 10.1.1.64.5699. doi:10.1177/1094342004041293. ISSN 1094-3420. S2CID 2563412.
Qing, Yi; Keith, Seymour; Haihang, You; Richard, Vuduc; Dan, Quinlan. "POET: Parameterized Optimizations for Empirical Tuning". 2007 IEEE International Parallel and Distributed Processing Symposium.
Chandramowlishwaran, A.; Knobe, K.; Vuduc, R. (April 2010). "Performance evaluation of concurrent collections on high-performance multicore computing systems". 2010 IEEE International Symposium on Parallel & Distributed Processing (IPDPS). pp. 1–12. CiteSeerX 10.1.1.169.5643. doi:10.1109/IPDPS.2010.5470404. ISBN 978-1-4244-6442-5. S2CID 1133093. |
Student teams-achievement divisions | Student teams-achievement divisions | Student teams-achievement divisions (STAD) is a Cooperative learning strategy in which small groups of learners with different levels of ability work together to accomplish a shared learning goal. It was devised by Robert Slavin and his associates at Johns Hopkins University. |
Student teams-achievement divisions | Student teams-achievement divisions | STAD is considered as one of the most researched, simplest, and most straightforward of all cooperative learning. It was established based on the fulfillment of instructional pedagogy. It is used in meeting well-defined instructional objectives. It is a learning strategy in which there are small group of learners with different levels of abilities, wherein they all come together to accomplish a shared learning goal. |
Student teams-achievement divisions | Working of STAD | The students are placed in small groups or teams. The class in its entirety is presented with a lesson and students are subsequently tested. Individuals are graded on the team's performance . Although the tests are taken individually, students are encouraged to work together to improve the overall performance of the group. It is basically a team work, but students are graded individually according to their contribution that they make towards their team. Usually in STAD students are assigned four to five members in a group that are mixed in performance level, gender, and ethnicity. |
Student teams-achievement divisions | Working of STAD | The teacher teaches a lesson to the students and they then work in teams and ensure that they have mastered the lesson. The students take individual quizzes on the material, at which they may not help each other. Their scores are compared to their own past averages and points are awarded on the basis of the degree to which students meet or exceed their own earlier performance. It encourages the students to take up responsibility for other members in their group as well as themselves. Thus in this way it is guaranteed that all group members with different levels are equally motivated to do their best. Slavin (1995) enumerated three main concepts of STAD as team rewards, individual accountability and for equal opportunities for success . Team rewards are certificates or either rewards which are given if a STAD group achieves higher than predetermined level . In this way a spirit of positive competition is reinforced and all or none of the groups would be rewarded based on how they score. In terms of individual accountability, the individual learning of each of the group members determines the success of the terms. |
Student teams-achievement divisions | Working of STAD | STAD has been used in a wide variety of subjects from mathematics to language, arts to social science and used from 2nd grade in schools through college. It is the most appropriate for teaching well defined objectives by incorporating more open-ended assessments, such as essays or performance.In STAD, students are assigned to four orfive5-member heterogeneous groups. Once these assignments are made, a four-step cycle is initiated: (i) teach, (ii) team study, (iii) test and (iv) recognition. |
Student teams-achievement divisions | Working of STAD | Teach In the teaching stage, the teacher presents materials usually in a lecture-discussion format. Students should be told what it is they are going to learn and why it is important.
Team study In the team study stage, group members work cooperatively with teacher-provided worksheets and answer sheets.
Test In the testing stage, each student individually takes a quiz. The teacher grades the quiz and notes the current scores as well as the improvement over previous quizzes.
Recognition Each team receives recognition awards depending on the average scores of each team. For example, teams that average 15 to 19 improvement points receive a GOOD TEAM certificate, teams that average 20 to 24 improvement points receive a GREAT TEAM certificate, and teams that average 25 to 30 improvement points receive a SUPER TEAM certificate. |
Student teams-achievement divisions | Components of STAD | Class presentation Teams Quizzes Individual improvement score Team recognition Advantages Group has greater information resources than individuals do Group has to employ a greater number of creative problem-solving methods Group members gain a better understanding of themselves as they interact with each other.
Working in a group foster learning and comprehension of idea discussed.
Disadvantages An individual group member may dominate the discussion.
Some group members may rely too much on others to get the job done.
Group members may pressure others to conform to the majority opinion. |
CX-516 | CX-516 | CX-516 is an ampakine and nootropic that acts as an AMPA receptor positive allosteric modulator and had been undergoing development by a collaboration between Cortex, Shire, and Servier. It was studied as a potential treatment for Alzheimer's disease under the brand name Ampalex, and was also being examined as a treatment for ADHD. |
CX-516 | CX-516 | CX-516 was the first ampakine compound developed by Cortex and while it showed good in vitro activity and positive results in animal tests, the human trials proved disappointing due mainly to low potency and short half-life. However, CX-516 is still widely used in animal research into the ampakine drugs and is the standard reference compound that newer, more potent drugs of this class such as farampator and CX-717 are compared to. |
Forelock | Forelock | The forelock or foretop is a part of a horse's mane, that grows from the animal's poll and falls forward between the ears and onto the forehead. Some breeds, particularly pony breeds, have a naturally thick forelock, while other breeds, such as many Thoroughbreds, have a thinner forelock. Primitive wild equines such as the Przewalski's horse with a naturally short, upright mane generally have no hair falling forward onto the forehead. Other equidae such as donkeys and zebras, have no discernible forelock at all. |
Forelock | Purpose | Little research has been published on the purpose of the forelock. However, the thick forelock is more prevalent in breeds developed in the cold, wet climates of northern Europe and is minimal on wild horse subspecies and other equine species adapted to hot, dry climates, such as the zebra or donkey. It tends to be fine and thin on many oriental horse breeds, even if they otherwise have long manes and tails. Thus, it may play a role in temperature regulation and to keep pests at bay. |
Forelock | Grooming | In competition the forelock is braided for some events, such as those in the dressage and hunt seat disciplines. Conversely, some breeds, such as the Andalusian, are usually shown with a long, full, forelock that is never braided. Other breeds may confine the forelock with rubber bands and anchor it to the bridle. The forelock may also be roached (shaved off) in some competitions, such as polo. |
Forelock | Human use | Forelock is slang for a human hairstyle popular in the 1980s. In the 19th century, it was a common salute where a person saluted another by "tugging the forelock" (see Salute). |
Reed mat (craft) | Reed mat (craft) | Reed mats are handmade mats of plaited reed or other plant material. |
Reed mat (craft) | East Asia | In Japan, a traditional reed mat is the tatami (畳). Tatami are covered with a weft-faced weave of soft rush (藺草, igusa) (common rush), on a warp of hemp or weaker cotton. There are four warps per weft shed, two at each end (or sometimes two per shed, one at each end, to cut costs). The doko (core) is traditionally made from sewn-together rice straw, but contemporary tatami sometimes have compressed wood chip boards or extruded polystyrene foam in their cores, instead or as well. The long sides are usually edged (縁, heri) with brocade or plain cloth, although some tatami have no edging. |
Reed mat (craft) | Southeast Asia | In the Philippines, woven reed mats are called banig. They are used as sleeping mats or floor mats, and were also historically used as sails. They come in many different weaving styles and typically have colorful geometric patterns unique to the ethnic group that created them. They are made from buri palm leaves, pandan leaves, rattan, or various kinds of native reeds known by local names like tikog, sesed (Fimbristykis miliacea), rono, or bamban.In Thailand and Cambodia, the mats are produced by plaiting reeds, strips of palm leaf, or some other easily available local plant. The supple mats made by this process of weaving without a loom are widely used in Thai homes. These mats are also now being made into shopping bags, place mats, and decorative wall hangings. |
Reed mat (craft) | Southeast Asia | One popular kind of Thai mat is made from a kind of reed known as Kachud, which grows in the southern marshes. After the reeds are harvested, they are steeped in mud, which toughens them and prevents them from becoming brittle. They are then dried in the sun for a time and pounded flat, after which they are ready to be dyed and woven into mats of various sizes and patterns. |
Reed mat (craft) | Southeast Asia | Other mats are produced in different parts of Thailand, most notably in the eastern province of Chanthaburi. Durable as well as attractive, they are plaited entirely by hand with an intricacy that makes the best resemble finely woven fabrics. |
Reed mat (craft) | South Asia | In India, reed mats (called paay in Tamil or chatai in Hindi) are used as cooling and eco-friendly floor coverings. |
Sommerfeld parameter | Sommerfeld parameter | The Sommerfeld parameter η, named after Arnold Sommerfeld, is a dimensionless quantity used in nuclear astrophysics in the calculation of reaction rates between two nuclei and also appears in the definition of the astrophysical S-factor. It is defined as η=Z1Z2e24πϵ0ℏv=αZ1Z2μc22E ,where e is the elementary charge, Z1 and Z2 are the atomic numbers of two interacting nuclides, v is the magnitude of the relative incident velocity in the center-of-mass frame, α is the unitless fine-structure constant, c is the speed of light, and μ is the reduced mass of the two nuclides of interest. |
Sommerfeld parameter | Sommerfeld parameter | One of its best-known applications is in the exponent of the Gamow factor P (also known as the penetrability factor), exp (−2πη) ,which is the probability of an s-wave nuclide to penetrate the Coulomb barrier, according to the WKB approximation. This factor is particularly helpful in characterizing the nuclear contribution to low-energy nucleon-scattering cross-sections - namely, through the astrophysical S-factor. |
Sommerfeld parameter | Sommerfeld parameter | One of the first articles in which the Sommerfeld parameter appeared was published in 1967. |
Symmetry | Symmetry | Symmetry (from Ancient Greek συμμετρία (summetría) 'agreement in dimensions, due proportion, arrangement') in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is invariant under some transformations, such as translation, reflection, rotation, or scaling. Although these two meanings of the word can sometimes be told apart, they are intricately related, and hence are discussed together in this article. |
Symmetry | Symmetry | Mathematical symmetry may be observed with respect to the passage of time; as a spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including theoretic models, language, and music.This article describes symmetry from three perspectives: in mathematics, including geometry, the most familiar type of symmetry for many people; in science and nature; and in the arts, covering architecture, art, and music. |
Symmetry | Symmetry | The opposite of symmetry is asymmetry, which refers to the absence or a violation of symmetry. |
Symmetry | In mathematics | In geometry A geometric shape or object is symmetric if it can be divided into two or more identical pieces that are arranged in an organized fashion. This means that an object is symmetric if there is a transformation that moves individual pieces of the object, but doesn't change the overall shape. The type of symmetry is determined by the way the pieces are organized, or by the type of transformation: An object has reflectional symmetry (line or mirror symmetry) if there is a line (or in 3D a plane) going through it which divides it into two pieces that are mirror images of each other. |
Symmetry | In mathematics | An object has rotational symmetry if the object can be rotated about a fixed point (or in 3D about a line) without changing the overall shape.
An object has translational symmetry if it can be translated (moving every point of the object by the same distance) without changing its overall shape.
An object has helical symmetry if it can be simultaneously translated and rotated in three-dimensional space along a line known as a screw axis.
An object has scale symmetry if it does not change shape when it is expanded or contracted. Fractals also exhibit a form of scale symmetry, where smaller portions of the fractal are similar in shape to larger portions.
Other symmetries include glide reflection symmetry (a reflection followed by a translation) and rotoreflection symmetry (a combination of a rotation and a reflection).
In logic A dyadic relation R = S × S is symmetric if for all elements a, b in S, whenever it is true that Rab, it is also true that Rba. Thus, the relation "is the same age as" is symmetric, for if Paul is the same age as Mary, then Mary is the same age as Paul.
In propositional logic, symmetric binary logical connectives include and (∧, or &), or (∨, or |) and if and only if (↔), while the connective if (→) is not symmetric. Other symmetric logical connectives include nand (not-and, or ⊼), xor (not-biconditional, or ⊻), and nor (not-or, or ⊽).
Other areas of mathematics Generalizing from geometrical symmetry in the previous section, one can say that a mathematical object is symmetric with respect to a given mathematical operation, if, when applied to the object, this operation preserves some property of the object. The set of operations that preserve a given property of the object form a group.
In general, every kind of structure in mathematics will have its own kind of symmetry. Examples include even and odd functions in calculus, symmetric groups in abstract algebra, symmetric matrices in linear algebra, and Galois groups in Galois theory. In statistics, symmetry also manifests as symmetric probability distributions, and as skewness—the asymmetry of distributions. |
Symmetry | In science and nature | In physics Symmetry in physics has been generalized to mean invariance—that is, lack of change—under any kind of transformation, for example arbitrary coordinate transformations. This concept has become one of the most powerful tools of theoretical physics, as it has become evident that practically all laws of nature originate in symmetries. In fact, this role inspired the Nobel laureate PW Anderson to write in his widely read 1972 article More is Different that "it is only slightly overstating the case to say that physics is the study of symmetry." See Noether's theorem (which, in greatly simplified form, states that for every continuous mathematical symmetry, there is a corresponding conserved quantity such as energy or momentum; a conserved current, in Noether's original language); and also, Wigner's classification, which says that the symmetries of the laws of physics determine the properties of the particles found in nature.Important symmetries in physics include continuous symmetries and discrete symmetries of spacetime; internal symmetries of particles; and supersymmetry of physical theories. |
Symmetry | In science and nature | In biology In biology, the notion of symmetry is mostly used explicitly to describe body shapes. Bilateral animals, including humans, are more or less symmetric with respect to the sagittal plane which divides the body into left and right halves. Animals that move in one direction necessarily have upper and lower sides, head and tail ends, and therefore a left and a right. The head becomes specialized with a mouth and sense organs, and the body becomes bilaterally symmetric for the purpose of movement, with symmetrical pairs of muscles and skeletal elements, though internal organs often remain asymmetric.Plants and sessile (attached) animals such as sea anemones often have radial or rotational symmetry, which suits them because food or threats may arrive from any direction. Fivefold symmetry is found in the echinoderms, the group that includes starfish, sea urchins, and sea lilies.In biology, the notion of symmetry is also used as in physics, that is to say to describe the properties of the objects studied, including their interactions. A remarkable property of biological evolution is the changes of symmetry corresponding to the appearance of new parts and dynamics. |
Symmetry | In science and nature | In chemistry Symmetry is important to chemistry because it undergirds essentially all specific interactions between molecules in nature (i.e., via the interaction of natural and human-made chiral molecules with inherently chiral biological systems). The control of the symmetry of molecules produced in modern chemical synthesis contributes to the ability of scientists to offer therapeutic interventions with minimal side effects. A rigorous understanding of symmetry explains fundamental observations in quantum chemistry, and in the applied areas of spectroscopy and crystallography. The theory and application of symmetry to these areas of physical science draws heavily on the mathematical area of group theory. |
Symmetry | In science and nature | In psychology and neuroscience For a human observer, some symmetry types are more salient than others, in particular the most salient is a reflection with a vertical axis, like that present in the human face. Ernst Mach made this observation in his book "The analysis of sensations" (1897), and this implies that perception of symmetry is not a general response to all types of regularities. Both behavioural and neurophysiological studies have confirmed the special sensitivity to reflection symmetry in humans and also in other animals. Early studies within the Gestalt tradition suggested that bilateral symmetry was one of the key factors in perceptual grouping. This is known as the Law of Symmetry. The role of symmetry in grouping and figure/ground organization has been confirmed in many studies. For instance, detection of reflectional symmetry is faster when this is a property of a single object. Studies of human perception and psychophysics have shown that detection of symmetry is fast, efficient and robust to perturbations. For example, symmetry can be detected with presentations between 100 and 150 milliseconds.More recent neuroimaging studies have documented which brain regions are active during perception of symmetry. Sasaki et al. used functional magnetic resonance imaging (fMRI) to compare responses for patterns with symmetrical or random dots. A strong activity was present in extrastriate regions of the occipital cortex but not in the primary visual cortex. The extrastriate regions included V3A, V4, V7, and the lateral occipital complex (LOC). Electrophysiological studies have found a late posterior negativity that originates from the same areas. In general, a large part of the visual system seems to be involved in processing visual symmetry, and these areas involve similar networks to those responsible for detecting and recognising objects. |
Symmetry | In social interactions | People observe the symmetrical nature, often including asymmetrical balance, of social interactions in a variety of contexts. These include assessments of reciprocity, empathy, sympathy, apology, dialogue, respect, justice, and revenge.
Reflective equilibrium is the balance that may be attained through deliberative mutual adjustment among general principles and specific judgments. |
Symmetry | In social interactions | Symmetrical interactions send the moral message "we are all the same" while asymmetrical interactions may send the message "I am special; better than you." Peer relationships, such as can be governed by the golden rule, are based on symmetry, whereas power relationships are based on asymmetry. Symmetrical relationships can to some degree be maintained by simple (game theory) strategies seen in symmetric games such as tit for tat. |
Symmetry | In the arts | There exists a list of journals and newsletters known to deal, at least in part, with symmetry and the arts. |
Symmetry | In the arts | In architecture Symmetry finds its ways into architecture at every scale, from the overall external views of buildings such as Gothic cathedrals and The White House, through the layout of the individual floor plans, and down to the design of individual building elements such as tile mosaics. Islamic buildings such as the Taj Mahal and the Lotfollah mosque make elaborate use of symmetry both in their structure and in their ornamentation. Moorish buildings like the Alhambra are ornamented with complex patterns made using translational and reflection symmetries as well as rotations.It has been said that only bad architects rely on a "symmetrical layout of blocks, masses and structures"; Modernist architecture, starting with International style, relies instead on "wings and balance of masses". |
Symmetry | In the arts | In pottery and metal vessels Since the earliest uses of pottery wheels to help shape clay vessels, pottery has had a strong relationship to symmetry. Pottery created using a wheel acquires full rotational symmetry in its cross-section, while allowing substantial freedom of shape in the vertical direction. Upon this inherently symmetrical starting point, potters from ancient times onwards have added patterns that modify the rotational symmetry to achieve visual objectives. |
Symmetry | In the arts | Cast metal vessels lacked the inherent rotational symmetry of wheel-made pottery, but otherwise provided a similar opportunity to decorate their surfaces with patterns pleasing to those who used them. The ancient Chinese, for example, used symmetrical patterns in their bronze castings as early as the 17th century BC. Bronze vessels exhibited both a bilateral main motif and a repetitive translated border design. |
Symmetry | In the arts | In carpets and rugs A long tradition of the use of symmetry in carpet and rug patterns spans a variety of cultures. American Navajo Indians used bold diagonals and rectangular motifs. Many Oriental rugs have intricate reflected centers and borders that translate a pattern. Not surprisingly, rectangular rugs have typically the symmetries of a rectangle—that is, motifs that are reflected across both the horizontal and vertical axes (see Klein four-group § Geometry). |
Symmetry | In the arts | In quilts As quilts are made from square blocks (usually 9, 16, or 25 pieces to a block) with each smaller piece usually consisting of fabric triangles, the craft lends itself readily to the application of symmetry. |
Symmetry | In the arts | In other arts and crafts Symmetries appear in the design of objects of all kinds. Examples include beadwork, furniture, sand paintings, knotwork, masks, and musical instruments. Symmetries are central to the art of M.C. Escher and the many applications of tessellation in art and craft forms such as wallpaper, ceramic tilework such as in Islamic geometric decoration, batik, ikat, carpet-making, and many kinds of textile and embroidery patterns.Symmetry is also used in designing logos. By creating a logo on a grid and using the theory of symmetry, designers can organize their work, create a symmetric or asymmetrical design, determine the space between letters, determine how much negative space is required in the design, and how to accentuate parts of the logo to make it stand out. |
Symmetry | In the arts | In music Symmetry is not restricted to the visual arts. Its role in the history of music touches many aspects of the creation and perception of music.
Musical form Symmetry has been used as a formal constraint by many composers, such as the arch (swell) form (ABCBA) used by Steve Reich, Béla Bartók, and James Tenney. In classical music, Bach used the symmetry concepts of permutation and invariance. |
Symmetry | In the arts | Pitch structures Symmetry is also an important consideration in the formation of scales and chords, traditional or tonal music being made up of non-symmetrical groups of pitches, such as the diatonic scale or the major chord. Symmetrical scales or chords, such as the whole tone scale, augmented chord, or diminished seventh chord (diminished-diminished seventh), are said to lack direction or a sense of forward motion, are ambiguous as to the key or tonal center, and have a less specific diatonic functionality. However, composers such as Alban Berg, Béla Bartók, and George Perle have used axes of symmetry and/or interval cycles in an analogous way to keys or non-tonal tonal centers. George Perle explains "C–E, D–F♯, [and] Eb–G, are different instances of the same interval … the other kind of identity. … has to do with axes of symmetry. C–E belongs to a family of symmetrically related dyads as follows:" Thus in addition to being part of the interval-4 family, C–E is also a part of the sum-4 family (with C equal to 0). |
Symmetry | In the arts | Interval cycles are symmetrical and thus non-diatonic. However, a seven pitch segment of C5 (the cycle of fifths, which are enharmonic with the cycle of fourths) will produce the diatonic major scale. Cyclic tonal progressions in the works of Romantic composers such as Gustav Mahler and Richard Wagner form a link with the cyclic pitch successions in the atonal music of Modernists such as Bartók, Alexander Scriabin, Edgard Varèse, and the Vienna school. At the same time, these progressions signal the end of tonality.The first extended composition consistently based on symmetrical pitch relations was probably Alban Berg's Quartet, Op. 3 (1910). |
Symmetry | In the arts | Equivalency Tone rows or pitch class sets which are invariant under retrograde are horizontally symmetrical, under inversion vertically. See also Asymmetric rhythm.
In aesthetics The relationship of symmetry to aesthetics is complex. Humans find bilateral symmetry in faces physically attractive; it indicates health and genetic fitness. Opposed to this is the tendency for excessive symmetry to be perceived as boring or uninteresting. Rudolf Arnheim suggested that people prefer shapes that have some symmetry, and enough complexity to make them interesting.
In literature Symmetry can be found in various forms in literature, a simple example being the palindrome where a brief text reads the same forwards or backwards. Stories may have a symmetrical structure, such as the rise and fall pattern of Beowulf. |