Estimation of the gradient of the solution of an adjoint diffusion equation by the Monte Carlo method

Abstract: For the case of isotropic diffusion we consider the representation of the weighted concentration of trajectories and its space derivatives in the form of integrals (with some weights) of the solution to the corresponding boundary value problem and its directional derivative of a convective velocity. If the convective velocity at the domain boundary is degenerate and some other additional conditions are imposed this representation allows us to construct an efficient 'random walk by spheres and balls' algorithm. When these conditions are violated, transition to modelling the diffusion trajectories by the Euler scheme is realized, and the directional derivative of velocity is estimated by the dependent testing method, using the parallel modelling of two closely-spaced diffusion trajectories. We succeeded in justifying this method by statistically equivalent transition to modelling a single trajectory after the first step in the Euler scheme, using a suitable weight. This weight also admits direct differentiation with respect to the initial coordinate along a given direction. The resulting weight algorithm for calculating concentration derivatives is especially efficient if the initial point is in the subdomain in which the coefficients of the diffusion equation are constant

random walk by spheres and balls algorithm


A note on multi-index polynomials of Dickson type and their applications in quantum optics

Abstract: We discuss the properties of a new family of multi-index Lucas type polynomials, which are often encountered in problems of intracavity photon statistics. We develop an approach based on the integral representation method and show that this class of polynomials can be derived from recently introduced multi-index Hermite like polynomials

Lucas type polynomials
multi-index polynomials
quantum optics
intracavity photon statistics
integral representation
generating functions


Product development: using a 3D computer model to optimize the stability of the Rocket TM powered wheelchair

Abstract: A three-dimensional (3D) lumped-parameter model of a powered wheelchair was created to aid the development of the Rocket prototype wheelchair and to help explore the effect of innovative design features on its stability. The model was developed using simulation software, specifically Working Model 3D. The accuracy of the model was determined by comparing both its static stability angles and dynamic behavior as it passed down a 4.8-cm (1.9") road curb at a heading of 45 degrees with the performance of the actual wheelchair. The model's predictions of the static stability angles in the forward, rearward, and lateral directions were within 9.3, 7.1, and 3.8% of the measured values, respectively. The average absolute error in the predicted position of the wheelchair as it moved down the curb was 2.2 cm/m (0.9" per 3'3") traveled. The accuracy was limited by the inability to model soft bodies, the inherent difficulties in modeling a statically indeterminate system, and the computing time. Nevertheless, it was found to be useful in investigating the effect of eight design alterations on the lateral stability of the wheelchair. Stability was quantified by determining the static lateral stability angles and the maximum height of a road curb over which the wheelchair could successfully drive on a diagonal heading. The model predicted that the stability was more dependent on the configuration of the suspension system than on the dimensions and weight distribution of the wheelchair. Furthermore, for the situations and design alterations studied, predicted improvements in static stability were not correlated with improvements in dynamic stability

3D computer model
product development
innovative design features
suspension system configuration
dynamic stability improvements
average absolute error
predicted position
soft bodies modeling
statically indeterminate system
computing time
design alterations effect
diagonal heading
weight distribution
Rocket TM powered wheelchair
4.8 cm


Natural language from artificial life

Abstract: This article aims to show that linguistics, in particular the study of the lexico-syntactic aspects of language, provides fertile ground for artificial life modeling. A survey of the models that have been developed over the last decade and a half is presented to demonstrate that ALife techniques have a lot to offer an explanatory theory of language. It is argued that this is because much of the structure of language is determined by the interaction of three complex adaptive systems: learning, culture, and biological evolution. Computational simulation, informed by theoretical linguistics, is an appropriate response to the challenge of explaining real linguistic data in terms of the processes that underpin human language

natural language
linguistics
lexico-syntactic aspects
ALife
adaptive systems
learning
culture
biological evolution
computational simulation
artificial life


A parallelized indexing method for large-scale case-based reasoning

Abstract: Case-based reasoning (CBR) is a problem solving methodology commonly seen in artificial intelligence. It can correctly take advantage of the situations and methods in former cases to find out suitable solutions for new problems. CBR must accurately retrieve similar prior cases for getting a good performance. In the past, many researchers proposed useful technologies to handle this problem. However, the performance of retrieving similar cases may be greatly influenced by the number of cases. In this paper, the performance issue of large-scale CBR is discussed and a parallelized indexing architecture is then proposed for efficiently retrieving similar cases in large-scale CBR. Several algorithms for implementing the proposed architecture are also described. Some experiments are made and the results show the efficiency of the proposed method

parallelized indexing method
large-scale case-based reasoning
problem solving methodology
artificial intelligence
bitwise indexing
similar prior case retrieval
performance
experiments


Property testers for dense Constraint Satisfaction programs on finite domains

Abstract: Many NP-hard languages can be "decided" in subexponential time if the definition of "decide" is relaxed only slightly. Rubinfeld and Sudan introduced the notion of property testers, probabilistic algorithms that can decide, with high probability, if a function has a certain property or if it is far from any function having this property. Goldreich, Goldwasser, and Ron constructed property testers with constant query complexity for dense instances of a large class of graph problems. Since many graph problems can be viewed as special cases of the Constraint Satisfaction Problem on Boolean domains, it is natural to try to construct property testers for more general cases of the Constraint Satisfaction Problem. In this paper, we give explicit constructions of property testers using a constant number of queries for dense instances of Constraint Satisfaction Problems where the constraints have constant arity and the variables assume values in some domain of finite size

NP-hard languages
property testers
probabilistic algorithms
constant query complexity
constraint satisfaction
dense instances
randomized sampling
subexponential time
graph problems
Constraint Satisfaction Problem


Multiple comparison methods for means

Abstract: Multiple comparison methods (MCMs) are used to investigate differences between pairs of population means or, more generally, between subsets of population means using sample data. Although several such methods are commonly available in statistical software packages, users may be poorly informed about the appropriate method(s) to use and/or the correct way to interpret the results. This paper classifies the MCMs and presents the important methods for each class. Both simulated and real data are used to compare the methods, and emphasis is placed on a correct application and interpretation. We include suggestions for choosing the best method. Mathematica programs developed by the authors are used to compare MCMs. By taking the advantage of Mathematica's notebook structure, all interested student can use these programs to explore the subject more deeply

multiple comparison procedures
population means
error rate
single-step procedures
step-down procedures
sales management
pack-age design


Convergence of finite element approximations and multilevel linearization for Ginzburg-Landau model of d-wave superconductors

Abstract: In this paper, we consider the finite element approximations of a recently proposed Ginzburg-Landau-type model for d-wave superconductors. In contrast to the conventional Ginzburg-Landau model the scalar complex valued order-parameter is replaced by a multicomponent complex order-parameter and the free energy is modified according to the d-wave paring symmetry. Convergence and optimal error estimates and some super-convergent estimates for the derivatives are derived. Furthermore, we propose a multilevel linearization procedure to solve the nonlinear systems. It is proved that the optimal error estimates and super-convergence for the derivatives are preserved by the multi-level linearization algorithm

Ginzburg-Landau model
d-wave
superconductivity
finite element method
nonlinear systems
error estimation
two-grid method
free energy
multilevel linearization


Supply chain optimisation in the paper industry

Abstract: We describe the formulation and development of a supply-chain optimisation model for Fletcher Challenge Paper Australasia (FCPA). This model, known as the paper industry value optimisation tool (PIVOT), is a large mixed integer program that finds an optimal allocation of supplier to mill, product to paper machine, and paper machine to customer, while at the same time modelling many of the supply chain details and nuances which are peculiar to FCPA. PIVOT has assisted FCPA in solving a number of strategic and tactical decision problems, and provided significant economic benefits for the company

supply chain optimisation
Fletcher Challenge Paper Australasia
paper industry value optimisation tool
PIVOT
large mixed integer program
optimal allocation
strategic decision problems
tactical decision problems
economic benefits


Social presence in telemedicine

Abstract: We studied consultations between a doctor, emergency nurse practitioners (ENPs) and their patients in a minor accident and treatment service (MATS). In the conventional consultations, all three people were located at the main hospital. In the teleconsultations, the doctor was located in a hospital 6 km away from the MATS and used a videoconferencing link connected at 384 kbit/s. There were 30 patients in the conventional group and 30 in the telemedical group. The presenting problems were similar in the two groups. The mean duration of teleconsultations was 951 s and the mean duration of face-to-face consultations was 247 s. In doctor-nurse communication there was a higher rate of turn taking in teleconsultations than in face-to-face consultations; there were also more interruptions, more words and more `backchannels' (e.g. `mhm', `uh-huh') per teleconsultation. In doctor-patient communication there was a higher rate of turn taking, more words, more interruptions and more backchannels per teleconsultation. In patient-nurse communication there was. relatively little difference between the two modes of consulting the doctor. Telemedicine appeared to empower the patient to ask more questions of the doctor. It also seemed that the doctor took greater care in a teleconsultation to achieve coordination of beliefs with the patient than in a face-to-face consultation

social presence
telemedicine
doctor
emergency nurse practitioners
patients
minor accident and treatment service
teleconsultations
videoconferencing link
face-to-face consultations
doctor-nurse communication
interruptions
backchannels
words
turn taking
patient-nurse communication
belief coordination
384 kbit/s
951 s
247 s


A work journal [librarianship]

Abstract: Keeping a work journal can be useful in exploring one's thoughts and feelings about work challenges and work decisions. It can help bring about greater fulfillment in one's work life by facilitating self-renewal, change, the search for new meaning, and job satisfaction. One example of a work journal which I kept in 1998 is considered. It touches on several issues of potential interest to midlife career librarians including the challenge of technology, returning to work at midlife after raising a family, further education, professional writing, and job exchange

work decisions
work challenges
job satisfaction
self-renewal
work journal
change
midlife career librarians
technology
further education
professional writing
job exchange


Hit the road, Jack

Abstract: Going freelance offers the potential of higher earnings, variety and independence - but also removes the benefits of permanent employment and can mean long distance travel and periods out of work. The author looks at the benefits and drawbacks - and how to get started as an IT contractor


Dousing terrorist funding: mission possible? [banks]

Abstract: The government is tightening its grip on terrorist money flows. But as the banking industry continues to expand its Patriot Act compliance activities, it is with the realization that a great deal of work remains to be done before the American financial system can become truly airtight. Identification instruments, especially drivers licenses, represent a significant weak spot

banking
Patriot Act
terrorist funding
identification


Relation between glare and driving performance

Abstract: The present study investigated the effects of discomfort glare on driving behavior. Participants (old and young; US and Europeans) were exposed to a simulated low- beam light source mounted on the hood of an instrumented vehicle. Participants drove at night in actual traffic along a track consisting of urban, rural, and highway stretches. The results show that the relatively low glare source caused a significant drop in detecting simulated pedestrians along the roadside and made participants drive significantly slower on dark and winding roads. Older participants showed the largest drop in pedestrian detection performance and reduced their driving speed the most. The results indicate that the de Boer rating scale, the most commonly used rating scale for discomfort glare, is practically useless as a predictor of driving performance. Furthermore, the maximum US headlamp intensity (1380 cd per headlamp) appears to be an acceptable upper limit

glare
driving performance
discomfort glare
simulated low-beam light source
road traffic
urban road
rural road
highway
deBoer rating scale


A geometric process equivalent model for a multistate degenerative system

Abstract: In this paper, a monotone process model for a one-component degenerative system with k+1 states (k failure states and one working state) is studied. We show that this model is equivalent to a geometric process (GP) model for a two-state one component system such that both systems have the same long-run average cost per unit time and the same optimal policy. Furthermore, an explicit expression for the determination of an optimal policy is derived

multistate degenerative system
geometric process equivalent model
monotone process model
one-component degenerative system
failure states
working state
two-state one component system
long-run average cost
optimal policy
replacement policy
renewal reward process


Predictive control of a high temperature-short time pasteurisation process

Abstract: Modifications on the dynamic matrix control (DMC) algorithm are presented to deal with transfer functions with varying parameters in order to control a high temperature-short time pasteurisation process. To control processes with first order with pure time delay models whose parameters present an exogenous variable dependence, a new method of free response calculation, using multiple model information, is developed. Two methods, to cope with those nonlinear models that allow a generalised Hammerstein model description, are proposed. The proposed methods have been tested, both in simulation and in real cases, in comparison with PID and DMC classic controllers, showing important improvements on reference tracking and disturbance rejection


Mathematical modelling of the work of the system of wells in a layer with the exponential law of permeability variation and the mobile liquid interface

Abstract: We construct and study a two-dimensional model of the work of the system of wells in a layer with the mobile boundary between liquids of various viscosity. We use a 'plunger' displacement model of liquids. The boundaries of the filtration region of these liquids are modelled by curves of the Lyapunov class. Unlike familiar work, we solve two-dimensonal problems in an inhomogeneous layer when the mobile boundary and the boundaries of the filtration region are modelled by curves of the Lyapunov class. We show the practical convergence of the numerical solution of the problems studied

2D model
work
well system
mathematical modelling
exponential law
permeability variation
mobile liquid interface
mobile boundary
viscosity
plunger displacement model
filtration region boundaries
Lyapunov class curves
inhomogeneous layer
convergence
numerical solution


Non-asymptotic confidence ellipsoids for the least-squares estimate

Abstract: We consider the finite sample properties of least-squares system identification, and derive non-asymptotic confidence ellipsoids for the estimate. The shape of the confidence ellipsoids is similar to the shape of the ellipsoids derived using asymptotic theory, but unlike asymptotic theory, they are valid for a finite number of data points. The probability that the estimate belongs to a certain ellipsoid has a natural dependence on the volume of the ellipsoid, the data generating mechanism, the model order and the number of data points available

nonasymptotic confidence ellipsoids
least-squares estimate
finite sample properties
least-squares system identification
probability
data generating mechanism
model order
data points


A dynamic method for weighted linear least squares problems

Abstract: A new method for solving the weighted linear least squares problems with full rank is proposed. Based on the theory of Liapunov's stability, the method associates a dynamic system with a weighted linear least squares problem, whose solution we are interested in and integrates the former numerically by an A-stable numerical method. The numerical tests suggest that the new method is more than comparative with current conventional techniques based on the normal equations

dynamic method
weighted linear least squares problems
Lyapunov stability
A-stable numerical method


Information-processing and computing systems at thermal power stations in China

Abstract: The development and commissioning of information-processing and computing systems (IPCSs) at four power units, each of 500 MW capacity at the thermal power stations Tszisyan' and Imin' in China, are considered. The functional structure and the characteristics of the functions of the IPCSs are presented as is information on the technology of development and experience in adjustments. Ways of using the experience gained in creating a comprehensive functional firmware system are shown

China
thermal power stations
information-processing systems
computing systems
commissioning
development
functional structure
functions characteristics
firmware system
500 MW


A characterization of generalized Pareto distributions by progressive censoring schemes and goodness-of-fit tests

Abstract: In this paper we generalize a characterization property of generalized Pareto distributions, which is known for ordinary order statistics, to arbitrary schemes of progressive type-II censored order statistics. Various goodness-of-fit tests for generalized Pareto distributions based on progressively censored data statistics are discussed


Linear complexity of polyphase power residue sequences

Abstract: The well known family of binary Legendre or quadratic residue sequences can be generalised to the multiple-valued case by employing a polyphase representation. These p-phase sequences, with p prime, also have prime length L, and can be constructed from the index sequence of length L or, equivalently, from the cosets of pth power residues and non-residues modulo-L. The linear complexity of these polyphase sequences is derived and shown to fall into four classes depending on the value assigned to b/sub 0/, the initial digit of the sequence, and on whether p belongs to the set of pth power residues or not. The characteristic polynomials of the linear feedback shift registers that generate these sequences are also derived

linear complexity
polyphase power residue sequences
binary Legendre sequences
quadratic residue sequences
multiple-valued case
p-phase sequences
polynomials
linear feedback shift registers
cryptographic applications
key stream ciphers
binary sequences


Evaluation of videoconferenced grand rounds

Abstract: We evaluated various aspects of grand rounds videoconferenced from a tertiary care hospital to a regional hospital in Nova Scotia. During a five-month study period, 29 rounds were broadcast (19 in medicine and 10 in cardiology). The total recorded attendance at the remote site was 103, comprising 70 specialists, nine family physicians and 24 other health-care professionals. We received 55 evaluations, a response rate of 53%. On a five-point Likert scale (on which higher scores indicated better quality), mean ratings by remote-site participants of the technical quality of the videoconference were 3.0-3.5, with the lowest ratings being for ability to hear the discussion (3.0) and to see visual aids (3.1). Mean ratings for content, presentation, discussion and educational value were 3.8 or higher. Of the 49 physicians who presented the rounds, we received evaluations from 41, a response rate of 84%. The presenters rated all aspects of the videoconference and interaction with remote sites at 3.8 or lower. The lowest ratings were for ability to see the remote sites (3.0) and the usefulness of the discussion (3.4). We received 278 evaluations from participants at the presenting site, an estimated response rate of about 55%. The results indicated no adverse opinions of the effect of videoconferencing (mean scores 3.1-3.3). The estimated costs of videoconferencing one grand round to one site and four sites were C$723 and C$1515, respectively. The study confirmed that videoconferenced rounds can provide satisfactory continuing medical education to community specialists, which is an especially important consideration as maintenance of certification becomes mandatory

videoconferenced grand rounds
tertiary care hospital
regional hospital
telemedicine
cardiology
health-care professionals
five-point Likert scale
remote sites
continuing medical education
certification


Semantic B2B integration: issues in ontology-based approaches

Abstract: Solving queries to support e-commerce transactions can involve retrieving and integrating information from multiple information resources. Often, users don't care which resources are used to answer their query. In such situations, the ideal solution would be to hide from the user the details of the resources involved in solving a particular query. An example would be providing seamless access to a set of heterogeneous electronic product catalogues. There are many problems that must be addressed before such a solution can be provided. In this paper, we discuss a number of these problems, indicate how we have addressed these and go on to describe the proof-of-concept demonstration system we have developed


Copyright of electronic publishing

Abstract: With the spreading of the Internet and the wide use of computers, electronic publishing is becoming an indispensable measure to gain knowledge and skills. Meanwhile, copyright is facing much more infringement than ever in this electronic environment. So, it is a key factor to effectively protect copyright of electronic publishing to foster the new publication fields. The paper analyzes the importance of copyright, the main causes for copyright infringement in electronic publishing, and presents viewpoints on the definition and application of fair use of a copyrighted work and thinking of some means to combat breach of copyright

electronic publishing copyright
Internet
copyright infringement
electronic environment
copyright protection
fair use
copyrighted work


Generic simulation approach for multi-axis machining. Part 1: modeling methodology

Abstract: This paper presents a new methodology for analytically simulating multi-axis machining of complex sculptured surfaces. A generalized approach is developed for representing an arbitrary cutting edge design, and the local surface topology of a complex sculptured surface. A NURBS curve is used to represent the cutting edge profile. This approach offers the advantages of representing any arbitrary cutting edge design in a generic way, as well as providing standardized techniques for manipulating the location and orientation of the cutting edge. The local surface topology of the part is defined as those surfaces generated by previous tool paths in the vicinity of the current tool position. The local surface topology of the part is represented without using a computationally expensive CAD system. A systematic prediction technique is then developed to determine the instantaneous tool/part interaction during machining. The methodology employed here determines the cutting edge in-cut segments by determining the intersection between the NURBS curve representation of the cutting edge and the defined local surface topology. These in-cut segments are then utilized for predicting instantaneous chip load, static and dynamic cutting forces, and tool deflection. Part 1 of this paper details the modeling methodology and demonstrates the capabilities of the simulation for machining a complex surface

multiple axis machining
generic modeling
tool path specification
complex surface machining
complex sculptured surfaces
systematic prediction
cutting edge profile
surface topology
NURBS curve


The simulated emergence of distributed environmental control in evolving microcosms

Abstract: This work continues investigation into Gaia theory (Lovelock, The ages of Gaia, Oxford University Press, 1995) from an artificial life perspective (Downing, Proceedings of the 7th International Conference on Artificial Life, p. 90-99, MIT Press, 2000), with the aim of assessing the general compatibility of emergent distributed environmental control with conventional natural selection. Our earlier system, GUILD (Downing and Zvirinsky, Artificial Life, 5, p.291-318, 1999), displayed emergent regulation of the chemical environment by a population of metabolizing agents, but the chemical model underlying those results was trivial, essentially admitting all possible reactions at a single energy cost. The new model, METAMIC, utilizes abstract chemistries that are both (a) constrained to a small set of legal reactions, and (b) grounded in basic fundamental relationships between energy, entropy, and biomass synthesis/breakdown. To explore the general phenomena of emergent homeostasis, we generate 100 different chemistries and use each as the basis for several METAMIC runs, as part of a Gaia hunt. This search discovers 20 chemistries that support microbial populations capable of regulating a physical environmental factor within their growth-optimal range, despite the extra metabolic cost. Case studies from the Gaia hunt illustrate a few simple mechanisms by which real biota might exploit the underlying chemistry to achieve some control over their physical environment. Although these results shed little light on the question of Gaia on Earth, they support the possibility of emergent environmental control at the microcosmic level


Electronic books: reports of their death have been exaggerated

Abstract: E-books will survive, but not in the consumer market - at least not until reading devices become much cheaper and much better in quality (which is not likely to happen soon). Library Journal's review of major events of the year 2001 noted that two requirements for the success of E-books were development of a sustainable business model and development of better reading devices. The E-book revolution has therefore become more of an evolution. We can look forward to further developments and advances in the future

electronic books
E-books
Library Journal


Simple...But complex

Abstract: FlexPro 5.0, from Weisang and Co., is one of those products which aim to serve an often ignored range of data users: those who, in FlexPro's words, are interested in documenting, analysing and archiving data in the simplest way possible. The online help system is clearly designed to promote the product in this market segment, with a very clear introduction from first principles and a hands-on tutorial, and the live project to which it was applied was selected with this in mind

FlexPro 5.0
data archiving
data analysis
data documentation
online help system
hands-on tutorial


An integrated optimization model for train crew management

Abstract: Train crew management involves the development of a duty timetable for each of the drivers (crew) to cover a given train timetable in a rail transport organization. This duty timetable is spread over a certain period, known as the roster planning horizon. Train crew management may arise either from the planning stage, when the total number of crew and crew distributions are to be determined, or from the operating stage when the number of crew at each depot is known as input data. In this paper, we are interested in train crew management in the planning stage. In the literature, train crew management is decomposed into two stages: crew scheduling and crew rostering which are solved sequentially. We propose an integrated optimization model to solve both crew scheduling and crew rostering. The model enables us to generate either cyclic rosters or non-cyclic rosters. Numerical experiments are carried out over data sets arising from a practical application

integrated optimization model
train crew management
duty timetable
rail transport organization
roster planning horizon
crew scheduling
crew rostering
cyclic rosters
noncyclic rosters
integer programming


Database technology in digital libraries

Abstract: Database technology advancements have provided many opportunities for libraries. These advancements can bring the world closer together through information accessibility. Digital library projects have been established worldwide to, ultimately, fulfil the needs of end users through more efficiency and convenience. Resource sharing will continue to be the trend for libraries. Changes often create issues which need to be addressed. Issues relating to database technology and digital libraries are reviewed. Some of the major challenges in digital libraries and managerial issues are identified as well

database technology
digital libraries
information accessibility
digital library projects
end users
resource sharing
managerial issues
data quality
interoperability
metadata
user interface
query processing


Least load dispatching algorithm for parallel Web server nodes

Abstract: A least load dispatching algorithm for distributing requests to parallel Web server nodes is described. In this algorithm, the load offered to a node by a request is estimated based on the expected transfer time of the corresponding reply through the Internet. This loading information is then used by the algorithm to identify the least load node of the Web site. By using this algorithm, each request will always be sent for service at the earliest possible time. Performance comparison using NASA and ClarkNet access logs between the proposed algorithm and commonly used dispatching algorithms is performed. The results show that the proposed algorithm gives 10% higher throughput than that of the commonly used random and round-robin dispatching algorithms

least load dispatching algorithm
parallel Web server nodes
Internet
transfer time
NASA access logs
ClarkNet access logs
throughput
round-robin dispatching algorithms
random dispatching algorithms
World Wide Web server


Research into telehealth applications in speech-language pathology

Abstract: A literature review was conducted to investigate the extent to which telehealth has been researched within the domain of speech-language pathology and the outcomes of this research. A total of 13 studies were identified. Three early studies demonstrated that telehealth was feasible, although there was no discussion of the cost-effectiveness of this process in terms of patient outcomes. The majority of the subsequent studies indicated positive or encouraging outcomes resulting from telehealth. However, there were a number of shortcomings in the research, including a lack of cost-benefit information, failure to evaluate the technology itself, an absence of studies of the educational and informational aspects of telehealth in relation to speech-language pathology, and the use of telehealth in a limited range of communication disorders. Future research into the application of telehealth to speech-language pathology services must adopt a scientific approach, and have a well defined development and evaluation framework that addresses the effectiveness of the technique, patient outcomes and satisfaction, and the cost-benefit relationship

telehealth applications
speech-language pathology
literature review
telemedicine
cost-effectiveness
patient outcomes
cost-benefit analysis
communication disorders
patient satisfaction


A multi-agent system infrastructure for software component marketplace: an ontological perspective

Abstract: In this paper, we introduce a multi-agent system architecture and an implemented prototype for a software component marketplace. We emphasize the ontological perspective by discussing ontology modeling for the component marketplace, UML extensions for ontology modeling, and the idea of ontology transfer which makes the multi-agent system adapt itself to dynamically changing ontologies

multi-agent system architecture
software component marketplace
ontology modeling
UML extensions
ontology transfer
dynamically changing ontologies
adaptation


What's best practice for open access?

Abstract: The business of publishing journals is in transition. Nobody knows exactly how it will work in the future, but everybody knows that the electronic publishing revolution will ensure it won't work as it does now. This knowledge has provoked a growing sense of nervous anticipation among those concerned, some edgy and threatened by potential changes to their business, others excited by the prospect of change and opportunity. The paper discusses the open publishing model for dissemination of research

open access
journal publishing
electronic publishing
business
open publishing model
research dissemination


Two issues in setting call centre staffing levels

Abstract: Motivated by a problem facing the Police Communication Centre in Auckland, New Zealand, we consider the setting of staffing levels in a call centre with priority customers. The choice of staffing level over any particular time period (e.g., Monday from 8 am-9 am) relies on accurate arrival rate information. The usual method for identifying the arrival rate based on historical data can, in some cases, lead to considerable errors in performance estimates for a given staffing level. We explain why, identify three potential causes of the difficulty, and describe a method for detecting and addressing such a problem

call centre staffing levels
police communication centre
Auckland
New Zealand
priority customers
arrival rate information
performance estimates
forecast error
nonstationarity
conditional Poisson process


Connection management for QoS service on the Web

Abstract: The current Web service model treats all requests equivalently, both while being processed by servers and while being transmitted over the network. For some uses, such as multiple priority schemes, different levels of service are desirable. We propose application-level TCP connection management mechanisms for Web servers to provide two different levels of Web service, high and low service, by setting different time-outs for inactive TCP connections. We evaluated the performance of the mechanism under heavy and light loading conditions on the Web server. Our experiments show that, though heavy traffic saturates the network, high level class performance is improved by as much as 25-28%. Therefore, this mechanism can effectively provide QoS guaranteed services even in the absence of operating system and network supports

connection management
Web service model
Internet
TCP connections
time-outs
quality of service
telecommunication traffic
client server system
Web transaction


Boolean operators and the naive end-user: moving to AND

Abstract: Since so few end-users make use of Boolean searching, it is obvious that any effective solution needs to take this reality into account. The most important aspect of a technical solution should be that it does not require any effort on the part of users. What is clearly needed is for search engine designers and programmers to take account of the information-seeking behavior of Internet users. Users must be able to enter a series of words at random and have those words automatically treated as a carefully constructed Boolean AND search statement

Boolean operators
AND operator
Boolean searching
search engine design
information-seeking behavior
Internet


An ACL for a dynamic system of agents

Abstract: In this article we present the design of an ACL for a dynamic system of agents. The ACL includes a set of conversation performatives extended with operations to register, create, and terminate agents. The main design goal at the agent-level is to provide only knowledge-level primitives that are well integrated with the dynamic nature of the system. This goal has been achieved by defining an anonymous interaction protocol which enables agents to request and supply knowledge without considering symbol-level issues concerning management of agent names, routing, and agent reachability. This anonymous interaction protocol exploits a distributed facilitator schema which is hidden at the agent-level and provides mechanisms for registering capabilities of agents and delivering requests according to the competence of agents. We present a formal specification of the ACL and of the underlying architecture, exploiting an algebra of actors, and illustrate it with the help of a graphical notation. This approach provides the basis for discussing dynamic primitives in ACL and for studying properties of dynamic multi agent systems, for example concerning the behavior of agents and the correctness of their conversation policies

ACL
dynamic system of agents
system of agents
agents
Agent Communication Languages
dynamic system
distributed facilitator
actors
anonymous interaction protocol


On the distribution of Lachlan nonsplitting bases

Abstract: We say that a computably enumerable (c.e.) degree b is a Lachlan nonsplitting base (LNB), if there is a computably enumerable degree a such that a>b, and for any c.e. degrees w, v<or=a, if a<or=wVvV b then either a<or=wV b or a<or=vV b. In this paper we investigate the relationship between bounding and nonbounding of Lachlan nonsplitting bases and the high/low hierarchy. We prove that there is a non-Low/sub 2/ c.e. degree which bounds no Lachlan nonsplitting base

Lachlan nonsplitting bases distribution
computably enumerable degree
Turing degrees


Non-nested multi-level solvers for finite element discretisations of mixed problems

Abstract: We consider a general framework for analysing the convergence of multi-grid solvers applied to finite element discretisations of mixed problems, both of conforming and nonconforming type. As a basic new feature. our approach allows to use different finite element discretisations on each level of the multi-grid hierarchy. Thus, in our multi-level approach, accurate higher order finite element discretisations can be combined with fast multi-level solvers based on lower order (nonconforming) finite element discretisations. This leads to the design of efficient multi-level solvers for higher order finite element discretisations


Responding to market trends with predictive segmentation [health care]

Abstract: Technology and technological advances have always been a part of healthcare, but often it's advances in treatment machinery and materials that get the attention. However, technology gains also occur behind the scenes in operations. One of the less glamorous but powerful technological advances available today is predictive segmentation, a phrase that means "a new way to assess and view individuals in the market based on their health status and health needs." Sophisticated databases, data mining, neural networks and statistical capabilities have enabled the development of predictive segmentation techniques. These predictive models for healthcare can identify who is likely to need certain services and who is likely to become ill. They are a significant departure from various geographical and attitudinal segmentation methods that healthcare strategists have used in the past to gain a better understanding of their customers

market trends
healthcare
predictive segmentation
data mining
neural networks


Observer-based strict positive real (SPR) feedback control system design

Abstract: Presents theory for stability analysis and design for a class of observer-based feedback control systems. Relaxation of the controllability and observability conditions imposed in the Yakubovich-Kalman-Popov lemma can be made for a class of nonlinear systems described by a linear time-invariant system with a feedback-connected cone-bounded nonlinear element. It is shown how a circle-criterion approach can be used to design an observer-based state feedback control which yields a closed-loop system with specified robustness characteristics. The approach is relevant for design with preservation of stability when a cone-bounded nonlinearity is introduced in the feedback loop. Important applications are to be found in nonlinear control with high robustness requirements

observer-based strict positive real feedback control system


Control of a thrust-vectored flying wing: a receding horizon - LPV approach

Abstract: This paper deals with the application of receding horizon methods to hover and forward flight models of an experimental tethered flying wing developed at Caltech. The dynamics of the system are representative of a vertical landing and take off aircraft, such as a Harrier around hover, or a thrust-vectored aircraft such as F18-HARV or X-31 in forward flight. The adopted control methodology is a hybrid of receding horizon techniques and control Lyapunov function (CLF)-based ideas. First, a CLF is generated using quasi-LPV methods and then, by using the CLF as the terminal cost in the receding horizon optimization, stability is guaranteed. The main advantage of this approach is that stability can be guaranteed without imposing constraints in the on-line optimization, allowing the problem to be solved in a more efficient manner. Models of the experimental set-up are obtained for the hover and forward flight modes. Numerical simulations for different time horizons are presented to illustrate the effectiveness of the discussed methods. Specifically, it is shown that a mere upper bound on the cost-to-go is not an appropriate choice for a terminal cost, when the horizon length is short. Simulation results are presented using experimentally verified model parameters

thrust-vectored flying wing control
receding horizon-LPV approach
hover flight models
forward flight models
tethered flying wing
Caltech
vertical landing take off aircraft
Harrier around hover
thrust-vectored aircraft
F18-HARV
X-31
receding horizon techniques
control Lyapunov function-based ideas
quasi-LPV methods
receding horizon optimization
stability guarantee
numerical simulations
terminal cost
nonlinear system


Tool and process improvements from MFC control system technology

Abstract: A new approach to MFC calibration links the physical parameters of nitrogen to the physical characteristics of various process gases. This precludes the conventional need for surrogate gases. What results is a physics-based tuning algorithm and enhanced digital control system that enables rearranging and gas change of digital MFCs. The end result should be better process control through more accurate gas flow. The new method also decreases the number of MFC spare parts required to back up a fab

MFC control system technology
calibration
process gas
surrogate gas
tuning algorithm
digital control
process control
gas flow
semiconductor fab
tool technology
mass flow controller
N/sub 2/


Application of heuristic methods for conformance test selection

Abstract: In this paper we focus on the test selection problem. It is modeled after a real-life problem that arises in telecommunication when one has to check the reliability of an application. We apply different metaheuristics, namely Reactive Tabu Search (RTS), Genetic Algorithms (GA) and Simulated Annealing (SA) to solve the problem. We propose some modifications to the conventional schemes including an adaptive neighbourhood sampling in RTS, an adaptive variable mutation rate in GA and an adaptive variable neighbourhood structure in SA. The performance of the algorithms is evaluated in different models for existing protocols. Computational results show that GA and SA can provide high-quality solutions in acceptable time compared to the results of a commercial software, which makes them applicable in practical test selection

telecommunication conformance test selection


Comments on "Frequency decomposition and computing of ultrasound medical images with wavelet packets"

Abstract: In this paper, errors and discrepancies in the subject paper [Cincotti et al. (2002)] are highlighted. A comment, concerning the axial resolution associated to the adopted processing procedure is also reported

ultrasound medical images
wavelet packets
frequency decomposition
axial resolution
medical diagnostic imaging


Ecological interface design: progress and challenges

Abstract: Ecological interface design (EID) is a theoretical framework for designing human-computer interfaces for complex socio-technical systems. Its primary aim is to support knowledge workers in adapting to change and novelty. This literature review shows that in situations requiring problem solving, EID improves performance when compared with current design approaches in industry. EID has been applied to industry-scale problems in a broad variety of application domains (e.g., process control, aviation, computer network management, software engineering, medicine, command and control, and information retrieval) and has consistently led to the identification of new information requirements. An experimental evaluation of EID using a full-fidelity simulator with professional workers has yet to be conducted, although some are planned. Several significant challenges remain as obstacles to the confident use of EID in industry. Promising paths for addressing these outstanding issues are identified. Actual or potential applications of this research include improving the safety and productivity of complex socio-technical systems

ecological interface design
human-computer interfaces
complex social technical systems
industry
productivity
user interface
human factors


Job rotation in an academic library: damned if you do and damned if you don't!

Abstract: This article considers job rotation-the systematic movement of employees from one job to another-as one of the many tools within the organizational development tool kit. There is a brief consideration of useful print and Internet literature on the subject as well as a discussion of the pros and cons of job rotation. The application of job rotation methods in Ryerson University Library, a small academic library, concludes the article in order to illustrate process and insights through example

job rotation
academic library
systematic employee movement
organizational development
Ryerson University Library


Computing grid unlocks research

Abstract: Under the UK government's spending review in 2000 the Office of Science and Technology was allocated Pounds 98m to establish a three year e-science research and development programme. The programme has a bold vision: to change the dynamic of the way science is undertaken. The term 'e-science' was introduced by John Taylor, director general of research councils in the Office of Science and Technology. He saw many areas of science becoming increasingly reliant on new ways of collaborative, multidisciplinary, interorganisation working. E-science is intended to capture these new modes of working. There are two major components to the programme: the science, and the infrastructure to support that science. The infrastructure is generally referred to as the Grid. The choice of name resonates with the idea of a future in which computing resources and storage, as well as expensive scientific facilities and software, can be accessed on demand, like electricity. Open source prototypes of the middleware are available and under development as part of the e-science programme and other international efforts

UK programme
grid computing
collaboration
computing resources
e-science
middleware
software
open source prototypes
scientific research


Sliding-mode control scheme for a class of continuous chemical reactors

Abstract: The synthesis of a robust control law for regulation control of a class of relative-degree-one nonlinear systems is presented. The control design is based on a sliding-mode uncertainty estimator, developed under a framework of algebraic-differential concepts. The closed-loop stability for the underlying closed-loop system is achieved via averaging techniques. Robustness of the proposed control scheme is proved in the face of noise measurements, model uncertainties and sustained disturbances. The performance of the proposed control law is illustrated with numerical simulations, comparing the proposed controller with a well tuned PI controller

sliding-mode control scheme
continuous chemical reactors
robust control law synthesis
relative-degree-one nonlinear systems
sliding-mode uncertainty estimator
algebraic-differential concepts
closed-loop stability
closed-loop system
averaging techniques
noise measurements
model uncertainties
sustained disturbances


Fuzzy logic controlled shunt active power filter for power quality improvement

Abstract: The simulation and experimental study of a fuzzy logic controlled, three-phase shunt active power filter to improve power quality by compensating harmonics and reactive power required by a nonlinear load is presented. The advantage of fuzzy control is that it is based on a linguistic description and does not require a mathematical model of the system. The fuzzy control scheme is realised on an inexpensive dedicated micro-controller (INTEL 8031) based system. The compensation process is based on sensing line currents only, an approach different from conventional methods, which require harmonics or reactive volt-ampere requirement of the load. The performance of the fuzzy logic controller is compared with a conventional PI controller. The dynamic behavior of the fuzzy controller is found to be better than the conventional PI controller. PWM pattern generation is based on carrierless hysteresis based current control to obtain the switching signals. Various simulation and experimental results are presented under steady state and transient conditions


The art of the cross-sell [accounting software]

Abstract: With the market for accounting software nearing saturation, vendors are training resellers in the subtleties of the cross-sell. The rewards can be great. The key is knowing when to focus, and when to partner

accounting software
resellers
cross-selling


Mathematical aspects of computer-aided share trading

Abstract: We consider problems of statistical analysis of share prices and propose probabilistic characteristics to describe the price series. We discuss three methods of mathematical modelling of price series with given probabilistic characteristics

computer-aided share trading
statistical analysis
share price
probabilistic characteristics
price series
mathematical modelling


L/sub p/ boundedness of (C, 1) means of orthonormal expansions for general exponential weights

Abstract: Let I be a finite or infinite interval, and let W:I to (0, infinity ). Assume that W/sup 2/ is a weight, so that we may define orthonormal polynomials corresponding to W/sup 2/. For f :R to R, let s/sub m/ [f] denote the mth partial sum of the orthonormal expansion of f with respect to these polynomials. We investigate boundedness in weighted L/sub p/ spaces of the (C, 1) means 1/n /sub m=1/ Sigma /sup n/s/sub m/[f]. The class of weights W/sup 2/ considered includes even and noneven exponential weights

boundedness
orthonormal expansions
general exponential weights
infinite interval
finite interval
orthonormal polynomials
mth partial sum


Embedded Linux and the law

Abstract: The rising popularity of Linux, combined with perceived cost savings, has spurred many embedded developers to consider a real-time Linux variant as an alternative to a traditional RTOS. The paper presents the legal implications for the proprietary parts of firmware

embedded Linux
real-time Linux
legal implications
proprietary firmware


Optimal and safe ship control as a multi-step matrix game

Abstract: The paper describes the process of the safe ship control in a collision situation using a differential game model with j participants. As an approximated model of the manoeuvring process, a model of a multi-step matrix game is adopted here. RISKTRAJ computer program is designed in the Matlab language in order to determine the ship's trajectory as a certain sequence of manoeuvres executed by altering the course and speed, in the online navigator decision support system. These considerations are illustrated with examples of a computer simulation of the safe ship's trajectories in real situation at sea when passing twelve of the encountered objects

ship control
collision avoidance
RISKTRAJ computer program
multistep matrix game
trajectory tracking
differential game
optimal control
decision support system
online navigation


Current waveform control of a high-power-factor rectifier circuit for harmonic suppression of voltage and current in a distribution system

Abstract: This paper presents the input current waveform control of the rectifier circuit which realizes simultaneously the high input power factor and the harmonics suppression of the receiving-end voltage and the source current under the distorted receiving-end voltage. The proposed input current waveform includes the harmonic components which are in phase with the receiving-end voltage harmonics. The control parameter in the proposed waveform is designed by examining the characteristics of both the harmonic suppression effect in the distribution system and the input power factor of the rectifier circuit. The effectiveness of the proposed current waveform has been confirmed experimentally

input current waveform control
high input power factor
receiving-end voltage
source current
distorted receiving-end voltage
input current waveform
receiving-end voltage harmonics
high-power-factor rectifier circuit
harmonic voltage suppression
harmonic current suppression
distribution system
200 V
60 Hz
8 kVA
2 kW


Impact of user satisfaction and trust on virtual team members

Abstract: Pressured by the growing need for fast response times, mass customization, and globalization, many organizations are turning to flexible organizational forms, such as virtual teams. Virtual teams consist of cooperative relationships supported by information technology to overcome limitations of time and/or location. Virtual teams require their members to rely heavily on the use of information technology and trust in coworkers. This study investigates the impacts that the reliance on information technology (operationalized in our study via the user satisfaction construct) and trust have on the job satisfaction of virtual team members. The study findings reveal that both user satisfaction and trust are positively related to job satisfaction in virtual teams, while system use was not found to play a significant role. These findings emphasize that organizations seeking the benefits of flexible, IT-enabled virtual teams must consider both the level of trust among colleagues, and the users' satisfaction with the information technology on which virtual teams rely

information technology
trust
IT
user satisfaction
job satisfaction
virtual team members


The necessity of real-time-fact and fiction in digital reference systems

Abstract: Current discussions and trends in digital reference have emphasized the use of real-time digital reference services. Recent articles have questioned both the utility and use of asynchronous services such as e-mail. This article uses data from the AskERIC digital reference service to demonstrate that asynchronous services are not only useful and used, but may have greater utility than real-time systems

real-time digital reference services
asynchronous services
e-mail
AskERIC
personalized Internet-based service
digital library


New voice over Internet protocol technique with hierarchical data security protection

Abstract: The authors propose a voice over Internet protocol (VoIP) technique with a new hierarchical data security protection (HDSP) scheme. The proposed HDSP scheme can maintain the voice quality degraded from packet loss and preserve high data security. It performs both the data inter-leaving on the inter-frame of voice for achieving better error recovery of voices suffering from continuous packet loss, and the data encryption on the intra-frame of voice for achieving high data security, which are controlled by a random bit-string sequence generated from a chaotic system. To demonstrate the performance of the proposed HDSP scheme, we have successfully verified and analysed the proposed approach through software simulation and statistical measures on several test voices

voice over Internet protocol
hierarchical data security protection
VoIP
HDSP scheme
packet loss
high data security
data interleaving
data encryption
random bit-string sequence
chaotic system
software simulation
statistical measures
packet voice communications


Isogenous of the elliptic curves over the rationals

Abstract: An elliptic curve is a pair (E, O), where E is a smooth projective curve of genus 1 and O is a point of E, called the point at infinity. Every elliptic curve can be given by a Weierstrass equation E : y/sup 2/ + a/sub 1/xy + a/sub 3/y = x/sup 3/ + a/sub 2/x/sup 2/ + a/sub 4/x + a/sub 6/. Let Q be the set of rationals. E is said to be defined over Q if the coefficients a/sub i/, i = 1, 2, 3, 4, 6 are rationals and O is defined over Q. Let E/Q be an elliptic curve and let E(Q)/sub tors/ be the torsion group of points of E defined over Q. The theorem of Mazur asserts that E(Q)/sub tors/ is one of the following 15 groups E(Q)/sub tors/ {Z/mZ, Z/mZ * Z/2mZ, m, = 1, 2, ..., 10, 12, m = 1, 2, 3, 4. We say that an elliptic curve E'/Q is isogenous to the elliptic curve E if there is an isogeny, i.e. a morphism phi : E to E' such that phi (O) = O, where O is the point at infinity. We give an explicit model of all elliptic curves for which E(Q)/sub tors/ is in the form Z/mZ where m = 9,10,12 or Z/2Z * Z/2mZ where m = 4, according to Mazur's theorem. Moreover, for every family of such elliptic curves, we give an explicit model of all their isogenous curves with cyclic kernels consisting of rational points

elliptic curves isogenous
rationals
smooth projective curve
Weierstrass equation
explicit model
Mazur's theorem
cyclic kernels


Supply chain infrastructures: system integration and information sharing

Abstract: The need for supply chain integration (SCI) methodologies has been increasing as a consequence of the globalization of production and sales, and the advancement of enabling information technologies. In this paper, we describe our experience with implementing and modeling SCIs. We present the integration architecture and the software components of our prototype implementation. We then discuss a variety of information sharing methodologies. Then, within the framework of a multi-echelon supply chain process model spanning multiple organizations, we summarize research on the benefits of intraorganizational knowledge sharing, and we discuss performance scalability


Fast and efficient algorithm for the multiplierless realisation of linear DSP transforms

Abstract: A fast algorithm having a pseudopolynomial run-time and memory requirement in the worst case is developed to generate multiplierless architectures at all wordlengths for constant multiplications in linear DSP transforms. It is also re-emphasised that indefinitely reducing operators for multiplierless architectures is not sufficient to reduce the final chip area. For a major reduction, techniques like resource folding must be used. Simple techniques for improving the results are also presented

multiplierless realisation
linear DSP transforms
pseudopolynomial run-time
memory requirement
wordlengths
constant multiplications
final chip area
resource folding


Where have all the PC makers gone?

Abstract: PC makers are dwindling. If you are planning to make a PC purchase soon, here are a few things to look out for before you buy


An operations research approach to the problem of the sugar cane selection

Abstract: Selection for superior clones is the most important aspect of sugar cane improvement programs, and is a long and expensive process. While studies have investigated different components of selection independently, there has not been a whole system approach to improve the process. This study observes the problem as an integrated system, where if one parameter changes the state of the whole system changes. A computer based stochastic simulation model that accurately represents the selection was developed. The paper describes the simulation model, showing its accuracy as well as how a combination of dynamic programming and branch and bound can be applied to the model to optimise the selection system, giving a new application of these techniques. The model can be directly applied to any region targeted by sugar cane breeding programs or to other clonally propagated crops


Digital-domain self-calibration technique for video-rate pipeline A/D converters using Gaussian white noise

Abstract: A digital-domain self-calibration technique for video-rate pipeline A/D converters based on a Gaussian white noise input signal is presented. The proposed algorithm is simple and efficient. A design example is shown to illustrate that the overall linearity of a pipeline ADC can be highly improved using this technique


View from the top [workflow & content management]

Abstract: International law firm Linklaters has installed a global document and content management system that is accessible to clients and which has helped it move online

international law firm
Linklaters
document management
content management
online


No-go areas? [content management]

Abstract: Alex Fry looks at how content management systems can be used to ensure website access for one important customer group, the disabled

disabled
content management systems
website access


Average optimization of the approximate solution of operator equations and its application

Abstract: In this paper, a definition of the optimization of operator equations in the average case setting is given. And the general result about the relevant optimization problem is obtained. This result is applied to the optimization of approximate solution of some classes of integral equations

operator equations
optimization
average case setting
integral equations
Gaussian measure
integral n-width


Plug-ins for critical media literacy: a collaborative program

Abstract: Information literacy is important in academic and other libraries. The paper looks at whether it would be more useful to librarians and to instructors, as well as the students, to deal with information-literacy skill levels of students beginning their academic careers, rather than checking them at the end. Approaching the situation with an eye toward the broader scope of critical media literacy opens the discussion beyond a skills inventory to the broader range of intellectual activity

information literacy
critical media literacy
collaborative program
academic libraries
instructors


Connecting the business without busting the budget

Abstract: The "multi-channel content delivery" model (MCCD) might be a new concept to you, but it is already beginning to replace traditional methods of business communications, print and content delivery, argues Darren Atkinson, CTO, FormScape

multi-channel content delivery
FormScape
documents
distributed output management
business process management
archive
retrieval
content management


Riccati-based preconditioner for computing invariant subspaces of large matrices

Abstract: This paper introduces and analyzes the convergence properties of a method that computes an approximation to the invariant subspace associated with a group of eigenvalues of a large not necessarily diagonalizable matrix. The method belongs to the family of projection type methods. At each step, it refines the approximate invariant subspace using a linearized Riccati's equation which turns out to be the block analogue of the correction used in the Jacobi-Davidson method. The analysis conducted in this paper shows that the method converges at a rate quasi-quadratic provided that the approximate invariant subspace is close to the exact one. The implementation of the method based on multigrid techniques is also discussed and numerical experiments are reported

Riccati-based preconditioner
invariant subspaces
large matrices
eigenvalues
diagonalizable matrix
projection type methods
Jacobi-Davidson method
multigrid techniques


An intelligent system combining different resource-bounded reasoning techniques

Abstract: In this paper, PRIMES (Progressive Reasoning and Intelligent multiple MEthods System), a new architecture for resource-bounded reasoning that combines a form of progressive reasoning and the so-called multiple methods approach is presented. Each time-critical reasoning unit is designed in such a way that it delivers an approximate result in time whenever an overload or a failure prevents the system from producing the most accurate result. Indeed, reasoning units use approximate processing based on two salient features. First, an incremental processing unit constructs an approximate solution quickly and then refines it incrementally. Second, a multiple methods approach proposes different alternatives to solve the problem, each of them being selected according to the available resources. In allowing several resource-bounded reasoning paradigms to be combined, we hope to extend their actual scope to cover more real-world application domains

resource-bounded reasoning techniques
intelligent multiple methods system
time-critical reasoning unit
approximate processing
complex systems
real-time performance
PRIMES
progressive reasoning


Spatial solutions [office furniture]

Abstract: Take the stress out of the office by considering the design of furniture and staff needs, before major buying decisions

office furniture
staff needs
buying decisions


Simulation of ecological and economical structural-type functions

Abstract: An optimization approach to the simulation of ecological and economical structural-type functions is proposed. A methodology for construction of such functions is created in an explicit analytical form

economical structural-type functions
optimisation approach
simulation
explicit analytical form


VONNA(HBP): a multimedia learning package on hotel budget planning

Abstract: In this paper, a new learning package, VONNA(HBP), which provides an interactive and online environment for novices to study and practice hotel budget planning, is introduced. Its design philosophy will be discussed thoughtfully with special focus on how to make use of the multimedia and Internet. According to literatures, learning packages are faced to be more effective in delivering teaching material. Researchers indicate that students using a self-paced learning package score higher than in a traditional classroom setting. Moreover, the learning package provides different scenarios for students to explore themselves in a practical environment and is more cost effective and systematic than lectures. Currently, most learning packages in hotel education are not implemented using multimedia with Internet access. Our paper describes a new learning package that fills the gaps. VONNA(HBP) requires participants to investigate operational budgets on various areas such as sales levels, payroll, inventory level, promotion strategies, and facilities planning, etc. Eventually, the students/novices are required to practice their skills in a comprehensive case about a hypothetical hotel. They need to solve managerial problems by a combination of budgetary planning on human resources, staff training programmes, facilities' maintenance and replacement, or promotion schemes. Analytical tools are available for students/novices to judge an appropriate decision in handling constrained resources

multimedia learning package
VONNA(HBP)
interactive online environment
hotel budget planning
Internet
teaching material delivery
self-paced learning package
hotel education
sales
payroll
inventory
promotion strategies
facilities planning
managerial problems
human resources
staff training programmes
facility maintenance
facility replacement
constrained resource handling


Theta functions with harmonic coefficients over number fields

Abstract: We investigate theta functions attached to quadratic forms over a number field K. We establish a functional equation by regarding the theta functions as specializations of symplectic theta functions. By applying a differential operator to the functional equation, we show how theta functions with harmonic coefficients over K behave under modular transformations

harmonic coefficients
differential operator
modular transformations
number fields
quadratic forms
functional equation
symplectic theta functions


Abstract: Analysis of exclusively kinetic two-link underactuated mechanical systems is undertaken. It is first shown that such systems are not full-state feedback linearizable around any equilibrium point. Also, the equilibrium points for which the system is small-time locally controllable (STLC) is at most a one-dimensional submanifold. A concept less restrictive than STLC, termed the small-time local output controllability (STLOC) is introduced, the satisfaction of which guarantees that a chosen configuration output can be controlled at its desired value. It is shown that the class of systems considered is STLOC, if the inertial coupling between the input and output is nonzero. Also, in such a case, the system is nonminimum phase. An example section illustrates all the results presented


Problems with my PDA

Abstract: Tom Berry has lost his PDA, and now he has an even better understanding of the risks and benefits of working on the move


Engineering plug-in software components to support collaborative work

Abstract: Many software applications require co-operative work support, including collaborative editing, group awareness, versioning, messaging and automated notification and co-ordination agents. Most approaches hard-code such facilities into applications, with fixed functionality and limited ability to reuse groupware implementations. We describe our recent work in seamlessly adding such capabilities to component-based applications via a set of collaborative work-supporting plug-in software components. We describe a variety of applications of this technique, along with descriptions of the novel architecture, user interface adaptation and implementation techniques for the collaborative work-supporting components that we have developed. We report on our experiences to date with this method of supporting collaborative work enhancement of component-based systems, and discuss the advantages of our approach over conventional techniques

software applications
co-operative work support
collaborative editing
group awareness
versioning
messaging
automated notification
plug-in software components
groupware
collaborative work tools


Holding on [workflow & content management]

Abstract: Marc Fresko of Cornwell Management Consultants says 'think ahead' when developing your electronic records management policy

Cornwell Management Consultants
electronic records management policy


Robot trajectory control using neural networks

Abstract: The use of a new type of neural network (NN) for controlling the trajectory of a robot is discussed. A control system is described which comprises an NN-based controller and a fixed-gain feedback controller. The NN-based controller employs a modified recurrent NN, the weights of which are obtained by training another NN to identify online the inverse dynamics of the robot. The work has confirmed the superiority of the proposed NN-based control system in rejecting large disturbances

time-varying nonlinear multivariable plant


DEVS simulation of distributed intrusion detection systems

Abstract: An intrusion detection system (IDS) attempts to identify unauthorized use, misuse, and abuse of computer and network systems. As intrusions become more sophisticated, dealing with them moves beyond the scope of one IDS. The need arises for systems to cooperate with one another, to manage diverse attacks across networks. The feature of recent attacks is that the packet delivery is moderately slow, and the attack sources and attack targets are distributed. These attacks are called "stealthy attacks." To detect these attacks, the deployment of distributed IDSs is needed. In such an environment, the ability of an IDS to share advanced information about these attacks is especially important. In this research, the IDS model exploits blacklist facts to detect the attacks that are based on either slow or highly distributed packets. To maintain the valid blacklist facts in the knowledge base of each IDS, the model should communicate with the other IDSs. When attack level goes beyond the interaction threshold, ID agents send interaction messages to ID agents in other hosts. Each agent model is developed as an interruptible atomic-expert model in which the expert system is embedded as a model component

intrusion detection system
IDS
intrusions
expert system
distributed intrusion detection system
cooperative intrusion detection
warning threshold


When reference works are not books-the new edition of the Guide to Reference Books

Abstract: The author considers the history of the Guide to Reference Books (GRB) and its importance in librarianship. He discusses the ways in which the new edition is taking advantage of changing times. GRB has become a cornerstone of the literature of U.S. librarianship. The biggest change GRB will undergo to become GRS (Guide to Reference Sources) will be designing it primarily as a Web product

reference works
Guide to Reference Books
history
librarianship
GRB
GRS
Guide to Reference Sources
Web product
Internet


Going electronic [auditing]

Abstract: A study group examines the issues auditors face in gathering electronic information as evidence and its impact on the audit

auditing
electronic information
assurance standards
audit evidence


Quadratic Gauss sums over finite commutative rings

Abstract: This article explicitly determines the quadratic Gauss sum over finite commutative rings

quadratic Gauss sum
finite commutative rings


Optimization-based design of fixed-order controllers for command following

Abstract: For discrete-time scalar systems, we propose an approach for designing feedback controllers of fixed order to minimize an upper bound on the peak magnitude of the tracking error to a given command input. The work makes use of linear programming to design over a class of closed-loop systems proposed for the rejection of non-zero initial conditions and bounded disturbances. We incorporate performance robustness in the form of a guaranteed upper bound on the peak magnitude of the tracking error under plant coprime factor uncertainty

optimization-based design
fixed-order controllers
command following
discrete-time scalar systems
feedback controllers
tracking error
linear programming
closed-loop systems
performance robustness
guaranteed upper bound
coprime factor uncertainty


Single-phase half-bridge converter topology for power quality compensation

Abstract: A high power factor half-bridge rectifier with neutral point switch clamped scheme is proposed. Three power switches are employed in the proposed rectifier. Two PWM control schemes are used to draw a sinusoidal line current with low current distortion. The control signals of the power switches are derived from the DC link voltage balance compensator, line current controller and DC link voltage regulator. The hysteresis current control scheme is employed to track the line current command. The proposed control scheme and the circuit configuration can be applied to the active power filter to eliminate the harmonic currents and compensate the reactive power generated from the nonlinear load. Analytical and experimental results are included to illustrate the validity and effectiveness of the proposed control scheme

single-phase half-bridge rectifier topology


Development of computer-mediated teaching resources for tourism distance education: the University of Otago model

Abstract: This article presents a qualitative account of the development of computer-mediated tourism distance learning resources. A distance learning model was developed at the Centre for Tourism, University of Otago (New Zealand) in 1998-1999. The article reviews the development of this Internet-based learning resource explaining the design and development of programme links (providing study information for students) and paper links (course material and learning features). The design of course material is reviewed with emphasis given to consistency of presentation between papers. The template for course material is described and illustrated and the article concludes with an overview of important design considerations


On the convergence of the Bermudez-Moreno algorithm with constant parameters

Abstract: A. Bermudez and C. Moreno (1981) presented a duality numerical algorithm for solving variational inequalities of the second kind. The performance of this algorithm strongly depends on the choice of two constant parameters. Assuming a further hypothesis of the inf-sup type, we present here a convergence theorem that improves on the one presented by A. Bermudez and C. Moreno. We prove that the convergence is linear, and we give the expression of the asymptotic error constant and the explicit form of the optimal parameters, as a function of some constants related to the variational inequality. Finally, we present some numerical examples that confirm the theoretical results

Bermudez-Moreno algorithm
duality numerical algorithm
variational inequalities
convergence theorem
asymptotic error constant
optimal parameters
constant parameters


p-Bezier curves, spirals, and sectrix curves

Abstract: We elucidate the connection between Bezier curves in polar coordinates, also called p-Bezier or focal Bezier curves, and certain families of spirals and sectrix curves. p-Bezier curves are the analogue in polar coordinates of nonparametric Bezier curves in Cartesian coordinates. Such curves form a subset of rational Bezier curves characterized by control points on radial directions regularly spaced with respect to the polar angle, and weights equal to the inverse of the polar radius. We show that this subset encompasses several classical sectrix curves, which solve geometrically the problem of dividing an angle into equal spans, and also spirals defining the trajectories of particles in central fields. First, we identify as p-Bezier curves a family of sinusoidal spirals that includes Tschirnhausen's cubic. Second, the trisectrix of Maclaurin and their generalizations, called arachnidas. Finally, a special class of epi spirals that encompasses the trisectrix of Delanges

p-Bezier curves
spirals
sectrix curves
polar coordinates
focal Bezier curves
rational Bezier curves
control points
radial directions
polar angle
geometry
angle division
equal spans
particle trajectories
central fields
sinusoidal spirals
cubic
arachnidas
epi spirals
trisectrix


H-matrix approximation for the operator exponential with applications

Abstract: We previously developed a data-sparse and accurate approximation to parabolic solution operators in the case of a rather general elliptic part given by a strongly P-positive operator . Also a class of matrices (H-matrices) has been analysed which are data-sparse and allow an approximate matrix arithmetic with almost linear complexity. In particular, the matrix-vector/matrix-matrix product with such matrices as well as the computation of the inverse have linear-logarithmic cost. In this paper, we apply the H-matrix techniques to approximate the exponent of an elliptic operator. Starting with the Dunford-Cauchy representation for the operator exponent, we then discretise the integral by the exponentially convergent quadrature rule involving a short sum of resolvents. The latter are approximated by the H-matrices. Our algorithm inherits a two-level parallelism with respect to both the computation of resolvents and the treatment of different time values. In the case of smooth data (coefficients, boundaries), we prove the linear-logarithmic complexity of the method


A transmission line fault-location system using the wavelet transform

Abstract: This paper describes the locating system of line-to-ground faults on a power transmission line by using a wavelet transform. The possibility of the location with the surge generated by a fault has been theoretically proposed. In order to make the method practicable, the authors realize very fast processors. They design the wavelet transform and location chips, and construct a very fast fault location system by processing the measured data in parallel. This system is realized by a computer with three FPGA processor boards on a PCI bus. The processors are controlled by UNIX and the system has a graphical user interface with an X window system

power transmission line fault-location system


Design of a stroke dependent damper for the front axle suspension of a truck using multibody system dynamics and numerical optimization

Abstract: A stroke dependent damper is designed for the front axle suspension of a truck. The damper supplies extra damping for inward deflections rising above 4 cm. In this way the damper should reduce extreme suspension deflections without deteriorating the comfort of the truck. But the question is which stroke dependent damping curve yields the best compromise between suspension deflection working space and comfort. Therefore an optimization problem is defined to minimize the maximum inward suspension deflection subject to constraints on the chassis acceleration for three typical road undulations. The optimization problem is solved using sequential linear programming (SLP) and multibody dynamics simulation software. Several optimization runs have been carried out for a small two degree of freedom vehicle model and a large full-scale model of the truck semi-trailer combination. The results show that the stroke dependent damping can reduce large deflections at incidental road disturbances, but that the optimum stroke dependent damping curve is related to the acceleration bound. By means of vehicle model simulation and numerical optimization we have been able to quantify this trade-off between suspension deflection working space and truck comfort

stroke dependent damper
front axle suspension
multibody system dynamics
numerical optimization
inward deflections
extreme suspension deflections
chassis acceleration
road undulations
sequential linear programming
full-scale model
truck semi-trailer combination
damping
incidental road disturbances
acceleration bound
vehicle model simulation
truck comfort


Towards the globalisation of the IS/IT function

Abstract: The IS/IT function has recently emerged from the peripheral aspects of the finance department to the centre of critical organisational change. There is an increasing dependency on its activities as systems extend beyond supporting the internal efficiency of the organisation to augmenting global performance. The growth of wide and local networks has resulted in communication possibilities that were not possible a few years ago. E-commerce challenges the achievements of the IS/IT function and is very prominent in the globalisation of modern organisations. The complexity and diversity of electronic exchange is also well documented (Hackney et al., 2000). This has a number of impacts on the development and implementation of IS/IT solutions for organisations involved in international trade. It is a conjecture that the IS/IT function is critically important for the alignment of the business to meet the demands of global competition, through building internal marketing strategies and creating knowledge based communities. There is clear evidence that IS/IT can lead to improved business performance and potentially for sustained competitive advantage. This is obviously true through the advent of new and emerging technologies such as the Internet

globalisation
IS/IT function
local area networks
wide area networks
e-commerce
electronic exchange
international trade
internal marketing strategies
knowledge based communities
Internet


Fast, accurate and stable simulation of power electronic systems using virtual resistors and capacitors

Abstract: Simulation of power electronic circuits remains a problem due to the high level of stiffness brought about by the modelling of switches as biresistors i.e. very low turn-on resistance and very high turn-off resistance. The merits and drawbacks of two modelling methods that address this problem are discussed. A modelling solution for ensuring numerically stable, accurate and fast simulation of power electronic systems is proposed. The solution enables easy connectivity between power electronic elements in the simulation model. It involves the modelling of virtual capacitance at switching nodes to soften voltage discontinuity due to the switch current suddenly going to zero. Undesirable ringing effects that may arise due to the interaction between the virtual capacitance and circuit inductance are eliminated by modelling virtual damping resistors in parallel to inductors that are adjacent to switching elements. A midpoint configuration method is also introduced for modelling shunt capacitors. A DC traction system is simulated using this modelling strategy and the results are included. Simulation results obtained using this modelling strategy are validated by comparison with the established mesh analysis technique of modelling. The simulation performance is also compared with the Power System Blockset commercial software

power electronic systems simulation
virtual resistors
virtual capacitors
turn-on resistance
high turn-off resistance
switch modelling
switching nodes
voltage discontinuity softening
ringing effects
DC traction system
mesh analysis technique
Power System Blockset software
computer simulation


The best circulant preconditioners for Hermitian Toeplitz systems.II. The multiple-zero case

Abstract: For pt.I. see SIAM J. Numer. Anal., vol. 38, p. 876-896. Circulant-type preconditioners have been proposed previously for ill-conditioned Hermitian Toeplitz systems that are generated by nonnegative continuous functions with a zero of even order. The proposed circulant preconditioners can be constructed without requiring explicit knowledge of the generating functions. It was shown that the spectra of the preconditioned matrices are uniformly bounded except for a fixed number of outliers and that all eigenvalues are uniformly bounded away from zero. Therefore the conjugate gradient method converges linearly when applied to solving the circulant preconditioned systems. Previously it was claimed that this result can be extended to the case where the generating functions have multiple zeros. The main aim of this paper is to give a complete convergence proof of the method for this class of generating functions

circulant preconditioners
Hermitian Toeplitz systems
multiple-zero case
nonnegative continuous functions
generating functions
preconditioned matrices
eigenvalues
conjugate gradient method


Pitch post-processing technique based on robust statistics

Abstract: A novel pitch post-processing technique based on robust statistics is proposed. Performances in terms of pitch error rates and pitch contours show the superiority of the proposed method compared with the median filtering technique. Further improvement is achieved through incorporating an uncertainty term in the robust statistics model

pitch post-processing technique
robust statistics
pitch error rates
pitch contours
median filtering
uncertainty term
speech quality
speech communications


Stability of Runge-Kutta methods for delay integro-differential equations

Abstract: We study stability of Runge-Kutta (RK) methods for delay integro-differential equations with a constant delay on the basis of the linear equation du/dt = Lu(t) + Mu(t- tau ) + K integral /sub t- tau //sup t/ u( theta )d theta , where L, M, K are constant complex matrices. In particular, we show that the same result as in the case K = 0 (Koto, 1994) holds for this test equation, i.e., every A-stable RK method preserves the delay-independent stability of the exact solution whenever a step-size of the form h = tau /m is used, where m is a positive integer

Runge-Kutta methods
delay integro-differential equations
constant delay
stability


Minimizing blossoms under symmetric linear constraints

Abstract: In this paper, we show that there exists a close dependence between the control polygon of a polynomial and the minimum of its blossom under symmetric linear constraints. We consider a given minimization problem P, for which a unique solution will be a point delta on the Bezier curve. For the minimization function f, two sufficient conditions exist that ensure the uniqueness of the solution, namely, the concavity of the control polygon of the polynomial and the characteristics of the Polya frequency-control polygon where the minimum coincides with a critical point of the polynomial. The use of the blossoming theory provides us with a useful geometrical interpretation of the minimization problem. In addition, this minimization approach leads us to a new method of discovering inequalities about the elementary symmetric polynomials

control polygon
polynomial
blossom minimization
symmetric linear constraints
Bezier curve
concavity
Polya frequency-control polygon
critical point
geometrical interpretation
inequalities
elementary symmetric polynomials


Healthy, wealthy and wise? [health sector document management]

Abstract: NHS spending will rise from Pounds 65.4bn in 2002 to Pounds 87.2bn in 2006, and by 2008, spending will total Pounds 105.6bn. David Tyler looks at how the health sector is already beginning to exploit IT, and particularly document management, to improve service and cut costs

NHS spending
document management
IT
ScanSoft PaperPort


Phase transition for parking blocks, Brownian excursion and coalescence

Abstract: In this paper, we consider hashing with linear probing for a hashing table with m places, n items (n<m), and l=m-n empty places. For a noncomputer science-minded reader, we shall use the metaphore of n cars parking on m places: each car c/sub i/ chooses a place p/sub i/ at random, and if p/sub i/ is occupied, c/sub i/ tries successively p/sub i/+1, p/sub i/+2, until it finds an empty place. Pittel [42] proves that when l/m goes to some positive limit beta <1, the size B/sub 1//sup m,l/ of the largest block of consecutive cars satisfies 2( beta -1-log beta ) B/sub 1//sup m,l/=2 log m-3 log log m+ Xi /sub m/, where Xi /sub m/ converges weakly to an extreme-value distribution. In this paper we examine at which level for n a phase transition occurs between B/sub 1//sup m,l/=o(m) and m-B/sub 1//sup m,l/=o(m). The intermediate case reveals an interesting behavior of sizes of blocks, related to the standard additive coalescent in the same way as the sizes of connected components of the random graph are related to the multiplicative coalescent

hashing
linear probing
Brownian excursion
coalescence
parking blocks
empirical processes


Robust L/sub 2/ disturbance attenuation for nonlinear systems with input dynamical uncertainty

Abstract: Deals with the problem of robust L/sub 2/ disturbance attenuation for nonlinear systems with input dynamical uncertainty. The input dynamical uncertainty is restricted to be minimum-phase and relative degree zero. A sufficient condition. is given such that the nonlinear system satisfies the L/sub 2/ gain performance and input-to-state stable property. Using this condition, a design approach is given for a smooth state feedback control law that solves the robust L/sub 2/ disturbance attenuation problem, and the approach is extended to a more general case where the nominal system has higher relative degree. Finally, a numerical example is given to demonstrate the proposed approach

robust L/sub 2/ disturbance attenuation
nonlinear systems
input dynamical uncertainty
sufficient condition
L/sub 2/ gain performance
input-to-state stable property
design approach
smooth state feedback control law
nominal system
robust control


Hermite interpolation by rotation-invariant spatial Pythagorean-hodograph curves

Abstract: The interpolation of first-order Hermite data by spatial Pythagorean-hodograph curves that exhibit closure under arbitrary 3-dimensional rotations is addressed. The hodographs of such curves correspond to certain combinations of four polynomials, given by Dietz et al. (1993), that admit compact descriptions in terms of quaternions - an instance of the "PH representation map" proposed by Choi et al. (2002). The lowest-order PH curves that interpolate arbitrary first-order spatial Hermite data are quintics. It is shown that, with PH quintics, the quaternion representation yields a reduction of the Hermite interpolation problem to three "simple" quadratic equations in three quaternion unknowns. This system admits a closed-form solution, expressing all PH quintic interpolants to given spatial Hermite data as a two-parameter family. An integral shape measure is invoked to fix these two free parameters

interpolation
spatial Pythagorean hodograph curves
first-order Hermite data
quaternions
polynomials
closed-form solution
integral shape measure


Wired right [accounting]

Abstract: From business intelligence to wireless networking to service providers, here is what you need to know to keep up to speed with a changing landscape

accounting
business intelligence
wireless networking
service providers


Happily ever after: plateauing as a means for long-term career satisfaction

Abstract: Little did I know when I attended Judith Bardwick's presentation on plateauing at the ALA annual convention in 1988 that it would turn out to be one of the most valuable sessions I would attend at any library conference, since it has enabled me to understand the phenomenon of plateauing and to use the strategies she suggested to rejuvenate my career and personal life continually. Key concepts and solutions from her book and from other literature on plateauing are summarized and examples given as to how I incorporated them into my life

plateauing
long-term career satisfaction
librarians
personal life


Account aggregation: shaping up portfolios

Abstract: CPA providers of financial planning services are providing clients with a unified view of their investments

financial planning services
account aggregation


Surface textures improve the robustness of stereoscopic depth cues

Abstract: This research develops design recommendations for surface textures (patterns of color on object surfaces) rendered with stereoscopic displays. In 3 method-of-adjustment procedure experiments, 8 participants matched the disparity of a circular probe and a planar stimulus rendered using a single visible edge. The experiments varied stimulus orientation and surface texture. Participants more accurately matched the depth of vertical stimuli than that of horizontal stimuli, consistent with previous studies and existing theory. Participants matched the depth of surfaces with large pixel-to-pixel luminance variations more accurately than they did surfaces with a small pixel-to-pixel luminance variation. Finally, they matched the depth of surfaces with vertical line patterns more accurately than they did surfaces with horizontal-striped texture patterns. These results suggest that designers can enhance depth perception in stereoscopic displays, and also reduce undesirable sensitivity to orientation, by rendering objects with surface textures using large pixel-to-pixel luminance variations

surface textures
robustness
stereoscopic depth cues
circular probe disparity
planar stimulus disparity
single visible edge
stimulus orientation
surface texture
pixel-to-pixel luminance variations
vertical line patterns
horizontal-striped texture patterns
depth perception
stereoscopic displays
orientation sensitivity reduction
object rendering


Existence theorems for nonconvex problems of variational calculus

Abstract: A solution to a variational calculus problem is studied under the conditions of integrant convexity. The existence theorem is proved. As an example, a function is given, which satisfies all the conditions of the theorem but is not convex

existence theorems
nonconvex problems
variational calculus
integrant convexity