bluuebunny/crossref_metadata_2025 huggingface dataset:
Asynchronous parallel algorithms for test set partitioned fault simulation
Authors: Krishnaswamy Dilip , Banerjee Prithviraj , Rudnick Elizabeth M. , Patel Janak H.
Published: January 2007

We propose two new asynchronous parallel algorithms for test set partitioned fault simulation. The algorithms are based on a new two-stage approach to parallelizing fault simulation for sequential VLSI circuits in which the test set is partitioned among the available processors. These algorithms provide the same result as the previous synchronous two stage approach. However, due to the dynamic characteristics of these algorithms and due to the fact that there is very minimal redundant work, they run faster than the previous synchronous approach. A theoretical analysis comparing the various algorithms is also given to provide an insight into these algorithms. The implementations were done in MPI and are therefore portable to many parallel platforms. Results are shown for a shared memory multiprocessor.
A workstation-based parallel direct-execution simulator
Authors: Dickens Phillip M.
Published: January 2007

It is important to understand and efficiently predict the performance of large codes executing on massively parallel machines. However, these very large machines are scarce, expensive, and generally unavailable to large segments of the research community. It is therefore important to implement performance analysis tools for such machines on platforms that are readily available to the research community at large. To meet this need, we have ported LAPSE, a parallel direct-execution simulator, from the Intel Paragon to an ordinary cluster of workstations. The goal of this research is to provide researchers the opportunity to study codes designed for execution on a massively parallel machine while physically executing on a workstation cluster. However, we encountered significant performance problems when moving to a workstation cluster, due primarily to high communication and context switching costs. To reduce these costs, we implemented the virtual processors of the simulated system using light-weight threads rather than heavy-weight Unix processes. In this paper, we discuss the issues involved in moving from a process-based to a thread-based simulator, and demonstrate up to a four fold increase in performance by doing so.
Education technology standards
Authors: Rada Roy , Schoening James
Published: January 2007

Standards are relevant to every ACM SIG. The new JavaScript standardization effort from the European Computer Manufacturers Association would be particularly relevant to SIG Software Engineering. Managing Multimedia Information Structures from the European Workshop for Open Systems would be particularly relevant to SIG Multimedia. The new ISO 14000 standards for environmental quality management systems might concern SIG Management Information Systems. One of the latest standardization efforts is for educational technology, and to our knowledge only one formal Standards Development Organization, namely the Institute of Electrical and Electronic Engineers (IEEE), is directly addressing educational technology standards.
Co-operative knowledge processing in software reuse
Authors: Kopácsi Sádor , Kovács George L.
Published: January 2007

The paper deals with the application of a given software reuse tool, and with its enhanced application based on the paradigm of Co-operative Knowledge Processing (CKP). CKP uses the web of shared understanding together with task-, result- and data-sharing. Thus specific knowledge based applications during the two important reuse processes (design for reuse and design with reuse) give a great increase in the efficiency of using reuse, having an appropriate repository co-operating with appropriate intelligent programs. As further enhancement a parallel processing algorithm is suggested, too.
Polynomial remainder sequence and approximate GCD
Authors: Sasaki Tateaki , Sasaki Mutsuko
Published: January 2007

Let P
1
and P
2
be polynomials, univariate or multivariate, and let (P
1
, P
2
, P
3
,…, P
i
,…) be a polynomial remainder sequence. Let A
i
and B
i
(i = 3, 4,…) be polynomials such that A
i
P
1
+ B
i
P
2
= P
i
, deg(A
i
) < deg(P
2
) - deg(P
i
), deg(B
i
) < deg(P
1
) - deg(P
i
), where the degree is for the main variable. We derive relations such as C
i
P
1
= -B
i+1
P
i
+ B
i
P
i+1
and C
i
P
2
= A
i+1
P
i
- A
i
P
i+1
, where C
i
is independent of the main variable. Using these relations, we discuss approximate common divisors calculated by polynomial remainder sequence.
Refiner
Authors: Hunt Kenny , Cremer James
Published: January 2007

It is well known in the simulation community that creating scientific simulations is a difficult task. The mathematical complexity and large scale of modern simulation systems presents the need for a programming environment that is able to assist the programmer in the code development cycle. Problem solving environments (PSEs) provide such an environment. This poster presents a program transformation based programming environment named Refiner.
The practical management of information ethics problems
Authors: Smith John W.
Published: January 2007

Part I of this discussion presented several case examples that are useful in exploring your institution's appropriate use policy with respect to ethical questions of
privacy.
Cases 1 and 2 test how well your policy deals with subordinate-superordinate relationships.
Re-centralizing
Authors: Wee Don M.
Published: January 2007

In the 80's, many schools and corporations had "Information Center" departments who were charged with promoting and supporting "end-user computing." We I.C. folks sponsored PC user groups and led discussions on whether people should upgrade right away to WordPerfect 4.2 or wait. We encouraged the spreadsheet guru in Finance to teach short-courses on 1 2--3. We installed a network file server for the Sociology Department, but asked the department to provide someone to do the backups and funnel questions, so we could teach one person how to use the network, who would then teach the rest. As the number of PCs exploded, we helped our institutions cope in the only cost-effective way available: we leveraged the available computer expertise by focusing training, support, and resources on key departmental computing coordinators. [1]
Information literacy
Authors: Larsen Lida L.
Published: January 2007

The phone rings and it's Dr. Withit who wants an Internet class for her students on how to find research material on the Web for their mid-term papers.
Improving TCP throughput over two-way asymmetric links
Authors: Kalampoukas Lampros , Varma Anujan , Ramakrishnan K. K.
Published: January 2007

The sharing of a common buffer by TCP data segments and acknowledgments in a network or internet has been known to produce the effect of
ack compression
, often causing dramatic reductions in throughput. We study several schemes for improving the performance of two-way TCP traffic over asymmetric links where the bandwidths in the two directions may differ substantially, possibly by many orders of magnitude. These approaches reduce the effect of ack compression by carefully controlling the flow of data packets and acknowledgments. We first examine a scheme where acknowledgments are transmitted at a higher priority than data. By analysis and simulation, we show that prioritizing acks can lead to starvation of the low-bandwidth connection. Next, we introduce and analyze a connection-level backpressure mechanism designed to limit the maximum amount of data buffered in the outgoing IP queue of the source of the low-bandwidth connection. We show that this approach, while minimizing the queueing delay for acks, results in unfair bandwidth allocation on the slow link. Finally, our preferred solution separates the acks from data packets in the outgoing queue, and makes use of a connection-level bandwidth allocation mechanism to control their bandwidth shares. We show that this scheme overcomes the limitations of the previous approaches, provides isolation, and enables precise control of the connection throughputs. We present analytical models of the dynamic behavior of each of these approaches, derive closed-form expressions for the expected connection efficiencies in each case, and validate them with simulation results.
Transient loss performance of a class of finite buffer queueing systems
Authors: Li Guang-Liang , Cui Jun-Hong , Li Bo , Li Fang-Ming
Published: January 2007

Performance-oriented studies typically rely on the assumption that the stochastic process modeling the phenomenon of interest is already in steady state. This assumption is, however, not valid if the life cycle of the phenomenon under study is not large enough, since usually a stochastic process cannot reach steady state unless time evolves towards infinity. Therefore, it is important to address performance issues in transient state.Previous work in transient analysis of queueing systems usually focuses on Markov models. This paper, in contrast, presents an analysis of transient loss performance for a class of finite buffer queueing systems that are not necessarily Markovian. We obtain closed-form transient loss performance measures. Based on the loss measures, we compare transient loss performance against steady-state loss performance and examine how different assumptions on the arrival process will affect transient loss behavior of the queueing system. We also discuss how to guarantee transient loss performance. The analysis is illustrated with numerical results.
A methodology and an evaluation of the SGI Origin2000
Authors: Jiang Dongming , Singh Jaswinder Pal
Published: January 2007

As hardware-coherent, distributed shared memory (DSM) multiprocessing becomes popular commercially, it is important to evaluate modern realizations to understand how they perform and scale for a range of interesting applications and to identify the nature of the key bottlenecks. This paper evaluates the SGI Origin2000---the machine that perhaps has the most aggressive communication architecture of the recent cache-coherent offerings---and, in doing so, articulates a sound methodology for evaluating real systems. We examine data access and synchronization microbenchmarks; speedups for different application classes, problem sizes and scaling models; detailed interactions and time breakdowns using performance tools; and the impact of special hardware support. We find that overall the Origin appears to deliver on the promise of cache-coherent shared address space multiprocessing, at least at the 32-processor scale we examine. The machine is quite easy to program for performance and has fewer organizational problems than previous systems we have examined. However, some important trouble spots are also identified, especially related to contention that is apparently caused by engineering decisions to share resources among processors.
Scheduling policies to support distributed 3D multimedia applications
Authors: Nguyen Thu D. , Zahorjan John
Published: January 2007

We consider the problem of scheduling the rendering component of 3D multimedia applications on a cluster of workstations connected via a local area network. Our goal is to meet a periodic real-time constraint.In abstract terms, the problem we address is how best to schedule tasks with unpredictable service times on distinct processing nodes so as to meet a real-time deadline, given that all communication among nodes entails some (possibly large) overhead. We consider two distinct classes of schemes,
static,
in which task reallocations are scheduled to occur at specific times, and
dynamic,
in which reallocations are triggered by some processor going idle. For both classes we further examine both
global
reassignments, in which all nodes are rescheduled at a rescheduling moment, and
local
reassignments, in which only a subset of the nodes engage in rescheduling at any one time.We show that global dynamic policies work best over a range of parameterizations appropriate to such systems. We introduce a new policy, Dynamic with Shadowing, that places a small number of tasks in the schedules of multiple workstations to reduce the amount of communication required to complete the schedule. This policy is shown to dominate the other alternatives considered over most of the parameter space.
Passage retrieval revisited
Authors: Kaszkiel Marcin , Zobel Justin
Published: January 2007

Ranking based on passages addresses some of the shortcomings of
whole-document ranking. It provides convenient units of text to
return to the user, avoids the difficulties of comparing documents
of different length, and enables identification of short blocks of
relevant material amongst otherwise irrelevant text. In this paper
we explore the potential of passage retrieval, based on an
experimental evaluation of the ability of passages to identify
relevant documents. We compare our scheme of arbitrary passage
retrieval to several other document retrieval and passage retrieval
methods; we show experimentally that, compared to these methods,
ranking via fixed-length passages is robust and effective. Our
experiments also show that, compared to whole-document ranking,
ranking via fixed-length arbitrary passages significantly improves
retrieval effectiveness, by 8% for TREC disks 2 and 4 and by
18%-37% for the Federal Register collection.
Hunting for the holy grail with “emotionally intelligent” virtual actors
Authors: Elliott Clark
Published: January 2007

In his keynote address to the Autonomous Agents 97 conference, Danny Hillis, vice president of research and development at Walt Disney Imagineering, listed four "holy grail" items with respect to entertainment agents:1. A computable science of emotion,2. Virtual actors,3. Agent evolution, and4. Computable storytelling.
The evaluation of framework reusability
Authors: Cardino Guido , Baruchelli Francesco , Valerio Andrea
Published: January 2007

Since reuse costs are often higher than expected, several approaches to development with reuse have been proposed. Among the most interesting is the idea of frameworks: sets of single components collaborating according to predefined cooperation rules. This approach can have a great impact on the reusability of parts of a software system, but it is not an easy task to give a quantitative measure of this reusability. The existing reusability metrics can be used, but the results are not fully satisfactory, since they do not take into account the peculiar characteristics of a framework and the particular way it is reused (a mix between black box reuse and white box reuse). For these reasons, a set of criteria adapting the traditional reusability metrics is proposed. These criteria try to evaluate the four main factors affecting the reusability of a framework: portability, adaptability, understandability, and confidence.
Performance of the Expressnet with voice/data traffic
Authors: Gonsalves Timothy A. , Tobagi Fouad A.
Published: January 2007

In the past few years, local area networks have come into widespread use for the interconnection of computers. Together with the trend towards digital transmission in voice telephony, this has spurred interest in integrated voice/data networks. The Expressnet, an implicit-token round-robin scheme using unidirectional busses, achieves high performance even at bandwidths of 100 Mb/s. Other features that make the protocol attractive for voice/data traffic are bounded delays and priorities. The latter is achieved by devoting alternate rounds to one or the other of the two traffic types. By the use of accurate simulation, the performance of the Expressnet with voice/data traffic is characterized. It is shown that the Expressnet satisfies the real-time constraints of voice traffic adequately even at bandwidths of 100 Mb/s. Data traffic is able to effectively utilize bandwidth unused by voice traffic. The trade-offs in the alternating round priority mechanism are quantified. Loss of voice samples under overload is shown to occur regularly in small, frequent clips, subjectively preferable to irregular clips. In a comparison of the Expressnet, the contention-based Ethernet and the round-robin Token Bus protocols, the two round-robin protocols are found to perform better than the Ethernet under heavy load owing to the more deterministic mode of operation. The comparison of the two round-robin protocols highlights the importance of minimizing scheduling overhead at high bandwidths.
Memory access patterns of parallel scientific programs
Authors: Darema-Rogers F. , Pfister G. F. , So K.
Published: January 2007

A parallel simulator, PSIMUL, has been used to collect information on the memory access patterns and synchronization overheads of several scientific applications. The parallel simulation method we use is very efficient and it allows us to simulate execution of an entire application program, amounting to hundreds of millions of instructions. We present our measurements on the memory access characteristics of these applications; particularly our observations on shared and private data, their frequency of access and locality. We have found that, even though the shared data comprise the largest portion of the data in the application program, on the average a small fraction of the memory references are to shared data. The low averages do not preclude bursts of traffic to shared memory nor does it rule out positive benefits from caching shared data. We also discuss issues of synchronization overheads and their effect on performance.
Predicting performance of concurrency control designs
Authors: Jipping Michael J. , Ford Ray
Published: January 2007

Performance is a high-priority consideration when designing concurrent or distributed systems. The process of designing such a system is complicated by two factors: (1) the current state-of-the-art in concurrent system design is very
ad hoc
— software design principles for concurrent systems are still in their infancy, and (2) performance evaluation of concurrent systems is quite difficult and it is especially difficult to relate aspects of the design to aspects of the implementation. This paper reports on work with a performance modeling technique for concurrent or distributed systems that allows structured
design
to be related to the
implementation
of the concurrency control component of the system. First, a General Process Model (GPM) is used to organize system design information into a six level hierarchy. The abstract performance properties of each level in the hierarchy have been established using concurrency control theory. Next, we describe how to translate the structured system design into efficient concurrency control techniques, using elements of this theory. Finally, a prototype automated design evaluation tool which serves as a central component of the design methodology is described.
Performance analysis of a fault detection scheme in multiprocessor systems
Authors: Dahbura Anton T. , Sabnani Krishan K. , Hery William J.
Published: January 2007

A technique is described for detecting and diagnosing faults at the processor level in a multiprocessor system. In this method, a process is assigned whenever possible to
two
processors: the processor that it would normally be assigned to (primary) and an additional processor which would otherwise be
idle
(secondary). Two strategies will be described and analyzed: one which is preemptive and another which is non-preemptive. It is shown that for moderately loaded systems, a sufficient percentage of processes can be performed redundantly using the system's spare capacity to provide a basis for fault detection and diagnosis with virtually no degradation of response time.
The effect of channel-exit protocols on the performance of finite population radom-access systems
Authors: Mathys Peter , Faltings Boi V.
Published: January 2007

Random-access systems (RAS) for collision-type channels have been studied extensively under the assumption of an infinite population which generates a Poisson arrival process. If the population is finite and if the (practically desirable) free-access channel-access protocol is used, then it is shown that the specification of a channel-exit protocol is crucial for the stability and the fairness of the RAS. Free-exit and blocked-exit protocols are analyzed and it is concluded that the p-persistent blocked-exit protocol provides the mechanisms to assure stability and fairness for a wide range of arrival process models.
Expert systems and information retrieval
Authors: Salton G.
Published: January 2007

The existing bibliographic retrieval systems are too complex to permit direct on-line access by untrained end users. Expert system approaches have been introduced in the hope of simplifying the document indexing, search and retrieval operations and rendering these operations accessible to end users. The expert system approach is examined briefly in this note and the conclusion is reached that expert systems are unlikely to provide much relief in ordinary retrieval environments. Simpler and more effective retrieval systems than those currently in use can be implemented by falling back on methodologies proposed and evaluated over twenty years ago that operate without expert system intervention.
Predicting the QoS of an electronic commerce server
Authors: Krishnamurthy Diwakar , Rolia Jerome
Published: January 2007

This paper presents a case study on Quality of Service (QoS) measures and Service Level Agreements (SLA) for an electronic commerce server. Electronic commerce systems typically rely on a combination of an HTTP server and a database server that may be integrated with other enterprise information resources. Some interactions with these systems cause requests for static HTML pages. Others cause significant amounts of database processing. Response time percentiles are well-accepted measures of QoS for such requests. In this paper we measure the behavior of an electronic commerce server under several controlled loads and study response time measures for several workload abstractions. Response time measures are captured for individual URLs, groups of functionally related URLs, and for sequences of URLs. We consider the utility of these workload abstractions for providing SLA. We also show that empirical evidence of server behavior in conjunction with analytic modeling techniques may be useful to predict the 90-percentile of response times for sequence based workload classes. The model predictions could be used to support realtime call admission algorithms.
Learning a word processing system with training wheels and guided exploration
Authors: Catrambone Richard , Carroll John M.
Published: January 2007

A Training Wheels interface creates a reduced functionality system intended to prevent new users from suffering the consequences of certain types of common errors when they exercise system functions and procedures. This has been shown to be an effective training system design for learning basic text editing functions [4]. We extend this result by examining the extent to which training wheels learners can transfer their skills to interaction with the full-function system. The experiment reported here indicates that training wheels subjects were better able to perform advanced full-system editing functions than subjects who were trained on the full system itself.
Developing computer animation packages (panel)
Authors: Graber Jeffrey , Lefebvre Kevin , Sciulli Michael , Leich Donald , Novacek Milan , Ross David , Zeltzer David , Sturman David
Published: January 2007

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.
Learning about hidden events in system interactions
Authors: Casner Stephen , Lewis Clayton
Published: January 2007

Understanding how to use a computer system often requires knowledge of hidden events: things which happen as a result of user actions but which produce no immediate perceptible effect. How do users learn about these events? Will learners explain the mechanism in detail or only at the level at which they are able to use it? We extend Lewis' EXPL model of causal analysis, incorporating ideas from Miyake, Draper, and Dietterich, to give an account of learning about hidden events from examples. We present experimental evidence suggesting that violations of user expectations trigger a process in which hidden events are hypothesized and subsequently linked to user actions using schemata for general classes of situations which violate user expectations.
Sophisticated image rendering in environmental design review
Authors: Danahy John W.
Published: January 2007

The Landscape Architecture Programme and the Computer Systems Research Institute at the University of Toronto undertook two studies using advanced rendering tools pioneered in the areas of computer animation and graphic art. Through two professional landscape architectural design studies we explored the potential role and impact of computer simulation in the initial, more creative phases of the design work. Advanced image rendering hardware and software were used to produce high quality computer drawings of design concepts. The techniques employed in this study are unique in their application to environmental design where they dramatically improve the designer's opportunities to simulate realistic images of proposed design alternatives and to consider the visual and spatial implications of such alternatives.

The case studies represented in the paper were undertaken for the National Capital Commission in Ottawa, Canada. The first project is an urban design massing study called the “Parliamentary Precinct Study” and the second project is a detailed design of the “Ceremonial Routes” in Ottawa.
The user interface and program structure of a graphical VLSI layout editor
Authors: Szabó Kevin S. B. , Elmasry Mohamed I.
Published: January 2007

In this paper the user interface and program organization of the
SYMPLE
VLSI symbolic layout editor is examined. The user interface is driven by a small interpreter that is constructed from a LISP-like language at run time and has access to a consistent library of menus and graphical information-gathering functions. To improve maintainability, the editor has been constructed in a modular form with well-defined interfaces.
A user interface for deaf-blind people (preliminary report)
Authors: Ladner Richard , Day randy , Gentry Dennis , Meyer Karin , Rose Scott
Published: January 2007

A user interface suitable for deaf-blind users is presented and justified. The interface is designed for small paperless Braille displays, large font visual displays, or other low-bandwidth displays. Some of the key properties of the interface are that it uses a hierarchical approach to structure both commands and data, has a small universal command set, and has pervasive editing capability. DBNet, a system employing the user interface, has been built and tested with deaf-blind users. DBNet will provide various communication services to the deaf-blind community including electronic news, mail, and bulletin boards.
How to write an APL utility function
Authors: Mansour Stephen M.
Published: January 2007

In today's business climate, reusable code is essential. But many programmers often don't use existing utility functions because they find them difficult to use or not general enough. Also, they may not know that such functions exist. Instead, programmers often clone lines of code from other functions. This results in sloppy, undocumented code which is full of errors. In order to avoid this, the author of a utility function must make an extra effort to ensure that his function is designed properly.APL is easy to learn because its primitives behave consistently, work on arrays as well as scalars, can handle edge conditions, often use default values and are totally encapsulated from the user. We can learn from this by designing utility functions in the same way, allowing them to become an extension of APL and its set of primitives. This paper will show some examples and design techniques.
Modeling multiprocessor computer systems with unbalanced flows
Authors: Madnick Stuart , Wang Y. Richard
Published: January 2007

A performance analysis methodology using certain aspects of queueing theory to evaluate computer system speed performance is presented. This methodology specifically focuses on modeling multiprocessor computer systems with unbalanced flows (i.e., number of transactions leaving a server is not the same as number of transactions entering that server) due to asynchronously spawned parallel tasks. This unbalanced flow phenomenon, which has a significant effect on performance, cannot be solved analytically by classical queueing network models.

A decomposition method is applied to decompose the unbalanced flows. Formulae for open queueing networks with unbalanced flows due to asynchronously spawned tasks are developed. Furthermore, an algorithm based on Buzen's convolution algorithm is developed to test the necessary and sufficient condition for closed system stability as well as to compute performance measures. An average of less than four iterations is reported for convergence with this algorithm.

A Study of the INFOPLEX multiprocessor data storage hierarchy, comparing this rapid solution algorithm with simulations, has shown highly consistent results. A cost effective software tool, using this methodology, has been developed to analyze an architectural design, such as INFOPLEX, and to produce measures such as throughput, utilization, and response time so that potential performance problems can be identified.
Waiting-time approximations for cyclic-service systems with switch-over times
Authors: Boxma O. J. , Meister B.
Published: January 2007

Mean waiting-time approximations are derived for a single-server multi-queue system with nonexhaustive cyclic service. Non-zero switch-over times of the server between consecutive queues are assumed. The main tool used in the derivation is a pseudo-conservation law recently found by Watson. The approximation is simpler and, as extensive simulations show, more accurate than existing approximations. Moreover, it gives very good insight into the qualitative behavior of cyclic-service queueing systems.
The effect of system workload on error latency
Authors: Chillarege Ram , Lyer Ravishankar K.
Published: January 2007

In this paper, a methodology for determining and characterizing error latency is developed. The method is based on real workload data, gathered by an experiment instrumented on a VAX 11/780 during the normal workload cycle of the installation. This is the first attempt at jointly studying error latency and workload variations in a full production system. Distributions of error latency were generated by simulating the occurrence of faults under varying workload conditions. A family of error latency distributions so generated illustrate that error latency is not so much a function of when in time a fault occurred but rather a function of the workload that followed the failure. The study finds that the mean error latency varies by a 1 to 8 (hours) ratio between high and low workloads. The method is general and can be applied to any system.
APL and demographic modelling
Authors: Piasentin U. , Lanari D. , Migliorini E.
Published: January 2007

Since the seventies the negative demographic growth in the western countries, and especially in Italy has led to a continuous population decrease and an increase in the number of aged people.This trend must be controlled for its inevitable negative effects on socio-economical relations and must be counteracted by new policies. The aim of this paper will be to suggest a way of handling demographic data which could be of easy access to a large number of users at various territorial levels (national, regional, subregional, municipal).In order to achieve this goal a method to implement the mathematical model for short and long term population projection will be provided. The software used will be Excel and APL2.Excel provides the variables and the input parameters of the model written in APL2, the projection results go back to the Excel environment in order to be processed and interpreted.
Using APL to build science tutors for the high school level
Authors: Alfonseca Manuel
Published: January 2007

This paper describes the procedure used to build several courses on the sciences for the high school level. An APL2 program has been written that accepts problem models, including explanation models, and uses them to generate many different problems. Each course is provided with about one hundred problem models, from which the student is invited to solve many thousands of different actual problems. The unique features of APL2 have made it very simple to develop the program that supports the courses. Versions exist for both DOS and Windows.
Highly parallel computing in simulation on dynamic bond portfolio management
Authors: Moriggia Vittorio , Bertocchi Marida , Dupaková Jitka
Published: January 2007

The bond portfolio management problem is formulated as a stochastic program based on interest rate scenarios. It has been proved in Dupaková (1998) that small errors in constructing scenarios will not destroy the optimal solution. The aim of the contribution is to quantify, through carefully planned simulation studies, the magnitude of the above-mentioned errors and to give bounds, at a specified confidence level, for the optimal gap between the value related to the optimal first-stage solution of the unperturbed problem and the "true" optimal value. Parallel computer numerical results are presented.
The use of Markov discontinuous processes in the pricing of derivative securities
Authors: Micocci Marco
Published: January 2007

The paper deals with one of the most important fields of research in modern financial theory: the valuation of derivatives. The aim of the work is the use of a discontinuous Markov process to model the dynamics of stock prices and, consequently to discover the right price of the derivative instruments, in place of the traditional binomial multiplicative process used frequently in many discrete models. At the end of the work various applications are presented. In them the stochastic process of the stock prices is modelled with the use of a simple and powerful APL program. In the applications APL shows all its capacity of calculation and matrix manipulation for mathematical uses.
Corporate analysis by APL
Authors: Juvonen Arto , Niemi Unto
Published: January 2007

This paper describes how APL has been used in Finland in the field of corporate analysis. The concept of corporate analysis is shortly introduced. A corporate analysis package, Trennus, is introduces. However, the emphasis of this paper is practical. It describes the concepts used in programming large Windows based software. The tools and ideas are universal and can be applied in any large software.
Database of the special functions of mathematical physics
Authors: Slavyanov S. Yu , Pirozhnikov A. B. , Lay W. , Yazik A. B.
Published: January 2007

We describe a knowledge-based computer project on the special functions of mathematical physics, which uses a unified structural approach to their classification. A prototype program package
SFTools
is presented. Special functions addressed by the system include hypergeometric-type functions, Heun functions, Painlevé transcendents and orthogonal polynomials. For these functions, basic differential equations are given with emphasis on singularities, integral relations, series expansions, Riemann P-symbols (Riemann scheme) and other important characteristics. In order to structure the information, we use the processes of confluence and reduction of equations widely.
A measurement analysis of Internet traffic over frame relay
Authors: Jerkins Judith L. , Monroe John , Wang Jonathan L.
Published: January 2007

Various approaches have been proposed and implemented to relieve the congestion in the Public Switched Telephone Networks (PSTNs) induced by recent meteoric growth of Internet services. The Internet/Intranet Transport Service (IITS) offered by the Southwestern Bell Telephone (SWBT) Company provides an example of one such implementation which off-loads the long-holding time data traffic from PSTNs to a packet technology (in this case Frame Relay).This paper describes analysis of 1997 IITS traffic jointly performed by SWBT and Bellcore with the goal of gaining insights into the nature of the Internet traffic over the Frame Relay technology, and deriving practical traffic engineering guidelines for efficiently managing the network elements to provide Quality-of-Service (QoS) to customers. The analysis was carried out at the
frame level
as well as the
call level.
The results demonstrate that traffic (both frame and byte count processes) at the
frame level
is self-similar with long-range dependent characteristics, while
call arrivals
are inhomogeneous Poisson processes and call holding times have heavy tails. Frame size statistics are explored, revealing a packet fragmentation issue that can unnecessarily decrease resource efficiency. The impacts of load balancing schemes (implemented by the equipment suppliers) on the traffic characteristics is also observed.
Internet-based groupware for user participation in product development
Authors: Divitini Monica , Farshchian Babak A. , Tuikka Tuomo
Published: January 2007

The workshop on Internet-based Groupware for User Participation in Product Development (IGROUP) was held on November 14, 1998, in conjunction with the conferences CSCW 98 and PDC 98 in Seattle, WA, USA. The workshop gathered 16 participants from both academia and industry. The topic discussed was how we can use groupware technology to involve end-users in the development of software and non-software products.The context for product development has traditionally been separated from the users' work context (Grudin 1991). In a product development process the user group is often unknown. Products are often purchased off-the-shelf, and the developers can in most cases only guess which user community and what types of users will be using their products. The only source of user feedback in these situations is from laboratory experiments with "typical users," and in some occasions from product resellers. The result is often sub-optimal solutions.In the recent years this picture has changed drastically. Technical innovations, in particular the Internet, have made it possible to bring closer together product developers and end-users. In its beginning, the developers started using a "feedback button" as a menu choice in their programs. Pushing this button would let the user compose a "complaint" message and send it to the developer. Lately, more advanced methods have emerged, trying to construct mixed communities of end-users and developers, where one of the aims is to deliver products users really want.In this workshop, we took a look at how groupware is or could be used to facilitate collaboration between users and developers in order to increase the quality of the product. Ten position papers discussed different aspects of user involvement using groupware technology. In this report we will first give a summary of the position papers and then discuss the areas that we saw as important for further investigation.
A preliminary comparison of body-wearable computers to modern audio equipment in a microgravity environment
Authors: Dooris Matthew , Moorman Michael , Gregory Bryan , Brown Marilyn , Wright Heather
Published: January 2007

The capabilities of body-wearable computers (BWC) and modern audio equipment were compared in a micro-gravity environment. In the experiment carried out, the speed of performance on timed tasks was compared for BWC and the audio playback devices currently used by astronauts. The BWC provided faster performance times than audio equipment when used in a micro-gravity environment. In addition, the BWC was found to provide faster performance times in normal gravity than in zero gravity.
Reading patterns and formats of academic articles on the Web
Authors: Rho Y. , Gedeon T. D.
Published: January 2007

Various formats are being used for Web-based academic articles such as conference papers and journal papers. We surveyed the formats being used and tried to identify reading activities and the proper formats by carrying out two online surveys: an email-based survey with an email-based questionnaire and a Web-based survey with a Web-based questionnaire.The survey results show that readers overview Web-based academic articles from the screen, print them out and then read the printed articles. The results also show that the structural formats employed by most papers on the Web are against readers' preferences. The simple two-frame format was most preferred by 47% of the respondents as readers, but the cascade format of page windows was regarded as the worst by 65%. An interesting result is that 26% of the respondents selected as the worst style the paper-like format that is currently widely used for Web-based articles. Brief data sets and results are shown in this article.In addition, the importance of examples embedded in the Web-based questionnaire was shown by two consecutive surveys.
Displaying search results in textual databases
Authors: Drori Offer
Published: January 2007

This article presents the preliminary results of a study currently in progress on the display of search results from textual databases. The study deals with information that should be displayed in a list of documents that match the user's search criteria.
HCI and the 3C convergence
Authors: Meng Helen M.
Published: January 2007

We attempt to explore the implications of the "3C convergence" (convergence of content, computers and communications) on the HCI research agenda. The interaction between humans and the 3C's is becoming a daily staple as we continue to witness powerful computers unite in a networked environment where wireline and wireless communications enjoy broadening bandwidths that permit the transmission of multimedia content. We draw illustrative examples from the Hong Kong environment related to the 3C convergence, and we present issues which we believe to be important for the research and development of a universal, useful and usable human-computer interface.
The friendly intelligent tutoring environment
Authors: Jerinic Ljubomir , Devedzic Vladan
Published: January 2007

The advancement of using the Artificial Intelligence (AI) methods and techniques in design Intelligent Tutoring Systems (ITSs) makes understanding them more difficult, so that teachers are less and less prepared to accept these systems. As a result, the gap between researchers in the field of ITSs and the educational community is constantly widening. While ITSs are becoming more common and proving to be increasingly effective, each one must still be built from scratch at a significant cost. Also present ITSs need quite big development environments, huge computing resources and, in consequence, are expensive and hardly portable to personal computers. This paper describes our efforts toward developing uniform data, explanation and control structures that can be used by a wide circle of authors who are involved in building ITSs (e.g., domain experts, teachers, curriculum developers, etc.) that is, the model of the ITSs framework, the
GET-BITS
model.
The practical management of information ethics problems
Authors: Smith John W.
Published: January 2007

The previous "Practical Management" article (Volume 29, No. 1--3, September 1998, pgs. 12--14) explored ethical questions that come from the distributed computing environment. It used four examples to explore issues associated with the physical domain - ownership, support, supplies, etc. This article will use the same examples to explore questions of intellectual property in the distributed environment.
Generating numerical ODE formulas via a symbolic calculus of divided differences
Authors: Geddes K. O.
Published: January 2007

Divided differences of vector functions can be applied to generate numerical update formulas for ODEs, as proposed by W. Kahan. A computer algebra system renders the symbolic manipulations practical to perform. The technique is presented here using the Maple system. Some examples illustrate the potential applications of this hybrid symbolic-numeric approach to solving initial-value problems.
Performance analysis of multiclass queueing networks
Authors: Bertsimas Dimitris , Gamarnik David , Tsitsiklis John N.
Published: January 2007

The subject of this abstract is performance analysis of multiclass queueing networks. The objective is to estimate steady-state queue lengths in queueing networks, assuming a priori that the scheduling policy implemented brings the system to a steady state, namely is stable. We propose a very general methodology based on Lyapunov functions, for the performance analysis of infinite state Markov chains and apply it specifically to multiclass exponential type queueing networks. We use, in particular, linear and piece-wise linear Lyapunov function to establish certain geometric type lower and upper bounds on the tail probabilities and bounds on expectation of the queue lengths. The results proposed in this paper are the first that establish geometric type upper and lower bounds on tail probabilities of queue lengths, for networks of such generality. The previous results on performance analysis can in general achieve only numerical bounds and only on expectation and not the distribution of queue lengths.
Progress in computational molecular biology
Authors: Hunter Lawrence
Published: January 2007

The nature of biological research is changing rapidly, due in large part to the advent of technologies for rapid generation of significant molecular data and the introduction of sophisticated computational methods. In this progress report, I discuss recent work in computational biology, focusing on gene expression analysis, high throughput screening of pharmaceutical leads, and information extraction from the biomedical literature.
Research and career development opportunities for meeting the challenges presented by the Human Genome project
Authors: Graham Bettie J.
Published: January 2007

This paper describes research and career development programs supported by the National Human Genome Research Institute. These programs focus on training the next generation of scientists who have degrees in computer sciences, mathematics, physics, chemistry, engineering or related quantitative sciences and who wish to make a significant contribution to the Human Genome Project or to broader areas of genomic science.