bluuebunny/crossref_metadata_2025 huggingface dataset:
An analytic study of dynamic hardware and software cache coherence strategies
Authors: Sandhu Harjinder S. , Sevcik Kenneth C.
Published: January 2007

Dynamic software cache coherence strategies use information about program sharing behaviour to manage caches at run-time and at a granularity defined by the application. The program-level information is obtained through annotations placed into the application by the user or the compiler. The coherence protocols may range from simple static algorithms to dynamic algorithms that use run-time data structures similar to the directories used in hardware strategies. In this paper, we present an analytic study of five dynamic software cache coherence algorithms and compare these to a representative hardware coherence strategy. The analytic model is constructed using four input parameters --- write probability, locality, granularity, and system size --- and solved by analysis of a Markov chain. We show that the fundamental tradeoffs between the different hardware and software strategies are captured in this model. The results of the study show that hardware schemes perform better for fine-grained data structures for much of the parameter space that we study. However, for coarse-grained data structures, various software algorithms are dominant over most of the parameter space. Further, hardware strategies are found to be more susceptible to the effects of contention, and also perform worse for the asymmetric workload that we study.
Calculating transient distributions of cumulative reward
Authors: de Souza e Silva Edmundo , Gail H. Richard , Campos Reinaldo Vallejos
Published: January 2007

Markov reward models have been employed to obtain performability measures of computer and communication systems. In these models, a continuous time Markov chain is used to represent changes in the system structure, usually caused by faults and repairs of its components, and reward rates are assigned to states of the model to indicate some measure of accomplishment at each structure. A procedure to calculate numerically the distribution of the reward accumulated over a finite observation period is presented. The development is based solely on probabilistic arguments, and the final recursion is quite simple. The algorithm has a low computational cost in terms of model parameters. In fact, the number of operations is linear in a parameter that is smaller than the number of rewards, while the storage required is independent of the number of rewards. We also consider the calculation of the distribution of cumulative reward for models in which impulse based rewards are associated with transitions.
Non-Markovian Petri nets
Authors: Trivedi Kishor S. , Bobbio A. , Ciardo G. , German R. , Puliafito A. , Telek M.
Published: January 2007

Non-Markovian models allow us to capture a very wide range of circumstances in which it is necessary to model phenomena whose times to occurrence is not exponentially distributed. Events such as timeouts in a protocol, service times at a machine performing the same task on each part, and memory access or instruction execution in a low-level h/w or s/w model, have durations which are constant or with a very low variance. Phase-type distributions can be used to approximate a non-exponential, but they increase the size of the state space.The analysis of stochastic systems with non-exponential timing is of increasing interest in the literature and requires the development of suitable modeling tools. Recently, some effort has been devoted to generalize the concept of
Stochastic Petri Nets
(SPN), by allowing the firing times to be generally distributed.A particular case of non-Markovian
SPN,
is the class of
Deterministic and SPN (DSPN)
[1]. A
DSPN
is a non-Markovian
SPN
where, in each marking, at most one transition is allowed to have a deterministic firing time with enabling memory policy.A new class of stochastic Petri nets has recently been defined [2, 3] by generalizing the deterministic firing times of the DSPN to generally distributed firing times. The underlying stochastic process for these classes of Petri nets is a
Markov Regenerative Process
(MRGP). This observation has opened a very fertile line of research aimed at the definition of solvable classes of models whose underlying marking process is an MRGP, and therefore referred to as
Markov Regenerative Stochastic Petri Nets (MRSPN).
Some of the results in this filed will be described in the session. In particular, Ciardo investigates stochastic confusion by defining the selection probability for transitions attempting to fire at the same time. German introduces the "method of supplementary variables" for the derivation of state equations describing the transient behavior of the marking process. Puliafito describes how, under some constraints, concurrent enabling of several generally distributed timed transitions is allowed. Bobbio and Telek discuss how age memory policy can be included to capture preemptive mechanisms of the resume
(prs)
type.
Fortran language extensions
Authors: Levine David
Published: January 2007

Current Fortran 90 implementations support a large number of extensions to the Standard language, most of which originated prior to F90. A great many user programs require at least some extensions. The "Implementations" Subgroup of X3J3 discussed the possibility of informally assembling some documentation of these extensions.
An adjustable user interface providing transparent access to application programs for the physically disabled
Authors: Piwetz Christian , Eiffert Frank , Heck Helmut , Müller-Clostermann Bruno
Published: January 2007

User interfaces of application programs are usually not designed for the physically disabled [VAN93]. Here we introduce a program for Apple Macintosh computers and PCs using MS-Windows that do assist handicapped users in their interaction with standard application programs. The basic principle is to interact with an interface agent and not with the target application itself, in particular text is entered to the application program via the interface that uses standard operating system mechanisms like the Inter Application Communication (IAC) in the case of the Macintosh. Hence a disabled user may access many different application programs using the same interface. An important feature is the integration of a text prediction component based on the context-sensitive algorithm used in the Reactive Keyboard due to John Darragh and Ian Witten [DWJ90, DAW92]. Currently stable protoype versions for Macintosh and MS-Windows are available.
A comparative study of ethical attitudes among MIS students and professionals
Authors: Benham Harry C. , Wagner Jennifer L.
Published: January 2007

This paper discusses attitudes toward ethical issues in information systems. Approximately 120 subjects were drawn from two populations: full-time undergraduate business students and full-time MIS employees who were also part-time students studying for a masters in MIS. Both groups were enrolled in an MIS course at the time of the study.The subjects read twenty information systems-based scenarios and classified the 31 behaviors described in them as Unacceptable, Questionable, or Acceptable. The results were compared to each other, as well as to the results of prior studies using the same instrument. The replication of earlier work with somewhat different subject groups provides the foundation for the present study. The prior studies showed South African students to be more "ethically lenient" than corresponding American students.The hypothesis that the MIS professionals would demonstrate a greater sensitivity to MIS ethical issues than either the undergraduate business or information systems majors is supported. Although earlier researchers have used undergraduates as substitutes for information systems personnel in many ethics studies, these two population groups do, in fact, differ.
The CL-PVM package
Authors: Li Liwei , Wang Paul S.
Published: January 2007

Parallel Virtual Machine
(PVM) is a software package that integrates a heterogeneous network of computers to form a single parallel/concurrent computing facility [2]. PVM consists of two parts: a run-time server and a set of library functions. A user sets up a
hostfile
that lists the names of the hosts constituting the
parallel virtual machine (pvm).
A PVM server runs on each host to help manage the
pvm.
Hosts can be added and deleted from the
pvm
dynamically. The
pvm
can be controlled from any constituent host either interactively from a
console
program or automatically from any
PVM tasks.
A PVM task is an application program that runs on a
pvm
and can use the PVM library functions to interact with other tasks: sending and receiving messages, initiating subtasks, detecting errors, etc. The PVM version 3.0 library is written in C allowing direct calls from C programs. There is also a Fortran 77 interface to give F77 programs access to the PVM library.CL-PVM provides a Common Lisp interface enabling Lisp-based programs to partake in PVM applications. A wide variety of useful Lisp programs exists including symbolic computation systems, expert systems, artificial intelligence systems, knowledge-based systems, and many more. With CL-PVM, the PVM library routines can be invoked interactively from the Lisp toplevel or from Lisp programs.The CL-PVM package contains a set of Common Lisp functions that interfaces Common Lisp (KCL, AKCL, or GCL) to the C-based library of PVM [2]. Generally, there is one CL interface function to each PVM C library function. The CL function calls its C-based counterpart and relays data to and from the C function. This interface is complete and allows Lisp-based programs to run on a
pvm
and thus facilitates the combination of symbolic, numeric, graphics, and other useful systems in a distributed fashion (Fig. 1). CL-PVM also offers a set of tools to aid effective use of the package with Lisp and MAXIMA tasks. Documentation, on-line manual pages, and examples are also included.CL-PVM is available by public FTP (ftp.mcs.kent.edu) in the directory (/pub/wang/). The package is described here. Please refer to [4] for more information on the design and implementation of the Lisp interface to PVM.
Monkey in the middle or building and supporting the human interface
Authors: Darrow Diane L.
Published: January 2007

More and more organizations are creating positions within their ranks that serve as "human interface" between the organization and their members or customers. I see this position in hotel companies (with national sales representatives), and most recently I have seen it in the management company that is contracted to manage the cooperative where I live. These positions are often precarious because they require the professional who is filling them to act as an intermediary, sometimes having to deliver unwelcome news to the parties they represent --- or even worse to the organization that pays their salary. There are some common traps that are easy to fall into if the management is not enlightened in the art of maximizing resources, or if the professional filling the job isn't strong and confident.
Teaching human computer interaction to programmers
Authors: Greenberg Saul
Published: January 2007

Many computer science graduates will likely find themselves developing interfaces in a work culture that has only naive notions of usability engineering. This article describes a course I developed that prepares students for this eventuality by providing them with practical and applicable HCI skills. All course material is available on the world wide web, and pointers are provided.
Long-term variation in user actions
Authors: Thomas Richard C.
Published: January 2007

There has been little research into the study of long term adaptation by users or the extent to which usage is enhanced over a substantial period [1]. However, there is general agreement that some interfaces, such as Unix shells and certain editors, take years to master. In this paper we present evidence that users do indeed change their actions in the long term. Some implications of our findings are discussed.
Guest editor's introduction
Authors: Welch Lonnie R. , Hammer Dieter K.
Published: January 2007

Object-orientation is an effective means to improve the software engineering process. It provides a natural approach to system modeling, and yields benefits in all lifecycle phases. While much progress has been made in general-purpose object-oriented methods, considerably less progress has been made in the domain of object-oriented real-time computing. In addition to the typical requirements of functional correctness, efficiency, and information hiding, object-oriented real-time systems must also conform to stringent timing requirements. An additional complicating factor is that real-time control systems are frequently distributed in nature. For researchers and engineers, this has ramifications for requirements, object specification, object composition, implementation, verification, testing, languages and run-time systems.
Benefits of type inference for an object-oriented real-time language
Authors: Gustafsson Jan , Post Kjell , Mäki-Turja Jukka , Brorsson Ellus
Published: January 2007

Real Time Talk is a framework and an object-oriented language for distributed hard real-time systems. This paper presents past, present, and future work in the Real Time Talk project. It concentrates on the language and programming part of Real Time Talk, and the problems a dynamically typed language impose on a real-time system.We look at how some of these problems can be solved by type inference and how type information can assist the compiler in accepting larger classes of real-time programs, generate more efficient and deterministic code, provide better estimation of execution times, and avoid run-time type errors. With type inference, one can have the best of two worlds --- efficiency and type safety, without the need for manual type declarations. An example is used to illustrate these ideas.
Checking timing constraints in distributed object-oriented programs
Authors: Gergeleit M. , Kaiser J. , Streich H.
Published: January 2007

In real-time systems design-assumptions can be divided into functional and temporal assumptions. While checks for functional correctness are already addressed by some modern programming languages (e.g. Eiffel's pre- and postconditions), checks for temporal correctness are usually out of the scope of the existing programming or runtime systems. Our work in the DIRECT [GKS94] project tries to fill this gap. A methodology for specifying and checking timing constraints in an object-oriented environment is presented. The approach extends previous work on RTL[JM86] (Real-Time Logic) based monitors towards an object-oriented responsive system. The paper focuses on how object-orientation can be utilized to simplify the specification and the checking of timing constraints and how this can be integrated into an existing programming language like C++.
A taxonomy for distributed object-oriented real-time systems
Authors: Hammer Dieter K. , Welch L. R. , van Roosmalen O. S.
Published: January 2007

This paper gives a taxonomy for the evaluation of object-oriented design methods and implementation languages for the construction of distributed real-time systems. This taxonomy is aimed at answering the following main questions: (1) how well do current approaches support the design of non-functional system features like concurrency and the specification of allocation, timing and fault tolerance constraints and (2) how can we discern essential properties of such methods and languages in order to point out the strengths and weaknesses of contemporary approaches.
The inevitable demise of the Web
Authors: Berghel Hal
Published: January 2007

There is no doubt that the fastest growing part of the Internet is the World Wide Web. From its inception in 1990, the Web has established itself as the leading packet hauler on the Internet, passing beyond FTP, Telnet, WAIS Gopher and all of the other, more established Internet client protocols. The reason for this success is that the Web has established itself as the standard unifying environment for the Internet's digital riches.However, the days of the Web are numbered. The technology behind the Web is outdated already and may not survive the decade. The c urrent growth rate, which some estimate at 15% per month, suggests that if the end of the Web is to come soon, it will likely be cataclysmal. If this seems unrealistic, consider that this fate befell Gopherspace. As Figure 1 shows, Gopher lead the Web in packet volume as late as March, 1994. In the following twelve months Gopher presence on the Internet all but disappeared. Life cycles are accelerated to frightening paces on the Internet.
Book review: Challenges in Natural Language Processing Madeleine Bates & Ralph M. Weischedel (Eds.) (Cambridge University Press 1993)
Authors: Hahn Udo
Published: January 2007

A recurrent event in almost every branch of science is the attempt of renowned experts from the field to look into its future. For the area of computational linguistics (CL) David Waltz, in 1982, has made the last assessment of the current state and future perspectives of natural language processing (NLP) research that I am aware of [1]. The book under review shares that predictive concern, ten years after. The intention behind-
Challenges in Natural Language Processing
1
is to explore the future shape of CL and to outline the most significant problems and challenges this field will face in the current decade. The papers it contains reflect the discussions from a symposium on
Future Directions in Natural Language Processing
which was held at Bolt Beranek and Newman, Inc. (BBN), in Cambridge, Massachusetts, from November 29, 1989 to December 1, 1989
2
. Access to this symposium was restricted to invited participants (people from government, industry, and academia, altogether thirty-six symposium attendees). Speakers were encouraged to present both recently completed and speculative work, and to focus on topics that they considered to have the most impact on the field in the coming (now, the current) decade. Their perception of unsolved problems of long standing and presentation of new possibilities was intended as a contribution to long-range planning by funding agencies, research groups, academic institutions, and others interested in CL. Except for the two contributions by the editors, which directly meet the intentions laid out above, the book contains an almost arbitrary collection of papers which could have been written on any other occasion, too. They cover highly specialized research topics but are uncommitted to in-depth deliberations concerning the future of CL. Therefore, I doubt that the targeted audience - even the domain specialists - will be focused on the field's perspectives after having read the published symposium contributions. In the strict sense, this book fails to accomplish its advisory goals. As a thematically entirely open collection of CL papers, it has its merits, nevertheless.
Cultural user interfaces
Authors: Yeo Alvin
Published: January 2007

Many software applications marketed outside the country of origin are internationalised and/or localised. In this article, I propose a strategy to localise the software by creating Cultural User Interface a (CUI) for each of the target cultures. A CUI is a user interface that is intuitive to a particular culture. The CUI takes advantage of the shared or common knowledge of a culture which could be defined by country boundaries, language, cultural conventions, race, shared activities or workplace. An application that is CUI-enabled allows the use of many different CUIs. These different CUIs are developed collaboratively with the target cultures, thus problems associated with localisation such as misinterpretation of elements in the CUIs, are unlikely to occur. A CUI can be used not only for one application but for a range of applications.Most software developers have accepted the fact that it is worthwhile economically to internationalise their software. This trend is evident in the growing number of companies that provide internationalisation and translation services for software marketed outside the United States (US). Also, many resources are now available on internationalisation and localisation of software. These resources include books (Kano (1995), Fernandes (1995), O'Donnell (1994), Uren et al. (1993), Apple (1992b), Digital (1992), Madell et al. (1992), Taylor (1992), Nielsen, (1990)), mailing lists (INSOFTL, intercultural.CHI), newsgroups (comp.software.international, comp.std.internat) and FAQs (ISO 8859-1 National Character Set FAQ, Programming for Internationalization FAQ, Globalizing Applications for Windows FAQ). Some examples of current articles written on these topics include Yeo and Barbour (1996), Karat and Karat (1996), Belge (1995), Chris Miller (1994), Hall (1994), and Nakakoji (1994). CHI Workshops have also been conducted (Kellogg and Thomas, 1993). Presently, there is an even further need for internationalised software that allows the use of non-Romanised characters given the popularity of WWW (see. http://www.w3.org/pub/WWW/International/).Current internationalisation and localisation of software has mainly focused on modifications of the language/character sets, collating sequence, the date, time, number and currency formats. As pointed out by Russo and Boor (1993) and Marcus (1993) there are many aspects that need to be addressed. One of these aspects is making provisions for the different perceptions of the diverse cultures.In this article, I discuss the differences in perception of user interface elements across cultures. A proposal and justification for many individually unique Cultural User Interfaces (CUIs) will be put forward. Lastly, technical implications of this proposal and a strategy to develop CUIs will be discussed.
In search of clickable dons
Authors: Rogers Yvonne , Aldrich Frances
Published: January 2007

As part of a university HCI course, masters students used and evaluated Norman's CD-ROM
Defending Human Attributes in the Age of the Machine
[1]. This paper reports on the advantages and disadvantages of the CD-ROM from the students'perspective, and reflects on the learning benefits of using this kind of interactive media. Problems with adapting existing books from paper to CD-ROM are discussed, and a number of suggestions are put forward of ways in which the interactivity of electronic media could be further exploited for teaching HCI and interface design.
A visual approach to HCI
Authors: Bottoni P. , Costabile M. F. , Levialdi S. , Mussio P.
Published: January 2007

The Pictorial Computing Laboratory (PCL) evolves its past experience in image processing and pattern recognition to the design of interactive systems. In the last ten years, a model for visual interactive computing has been developed based on the following abstraction: in interactive activities human beings communicate with computers through digital messages representing (part of) the state of the computation. Such a model, called

Com
2
,

is described, and an interaction with a system, developed following it, is shown as example, thus highlighting the use of visual languages for human-computer interaction.
Virtual ECHO
Authors: Meloni Daniela , Mura Alessandro , Nucci Francesco S. , Cangelosi Angelo , Ligorio Maria Beatrice
Published: January 2007

ECHO is a simulated environment with multimedia technology aimed to training specialized technical staff in using radar techniques. The system was designed using the user-centered perspective and a relevant knowledge acquisition phase in order to define a suitable Human-Computer Interface. The interface chosen for the system is the visit metaphor in order to leave the student free in exploring a virtual environment.ECHO was designed by the Advanced Methodologies and Interface Design group (MEDIA group), of the L.I.T (Laboratory of Information Technologies) of the AleniaThe paper, after a brief MEDIA group description, discusses the theory (as the theoretical framework and system architecture), as well as the user interface specific aspects (as the basic idea, the functionalities, and the interface structure). Finally the paper describes some implementation notes.
Human-computer interaction through natural language and hypermedia in AlFresco
Authors: Stock Oliviero , Strapparava Carlo , Zancanaro Massimo
Published: January 2007

Multimodality is a powerful concept for dealing with dialogue cohesion in a Human-Computer Natural Language centered system. Two issues, important for a the more effective exploitation of the potentially large bandwidth of communication provided by this situation are presented: (i) the integration of navigational and mediated aspects of interaction; (ii) the use of a graphical representation of the dialogue structure to allow the possibility of direct manipulation. Examples from real interaction with A
L
F
RESCO
, a prototype for art exploration, are used to give a concrete idea of the implemented concepts.
WAB
Authors: Kennel Andrea , Perrochon Louis , Darvishi Alireza
Published: January 2007

A blind or visually impaired user can get lost in hyperspace on one single W3-page. This paper presents Web Access for Blind users (WAB), a working system which makes web-surfing easier for blind persons. Normally, structure and meta information in HTML documents are displayed visually and are difficult for blind users to recognize. WAB transforms structure and meta information into a form that can be more easily read by visually handicapped people. Titles, links and form elements are described textually. Special navigation aids allow the blind user to navigate through the title hierarchy as well as through the list of links. The implemented system works with any World-Wide-Web-browser and any screen reader. No additional software has to be installed on the user's computer.
Limits on the performance benefits of multithreading and prefetching
Authors: Lim Beng-Hong , Bianchini Ricardo
Published: January 2007

This paper presents new analytical models of the performance benefits of multithreading and prefetching, and experimental measurements of parallel applications on the MIT Alewife multiprocessor. For the first time, both techniques are evaluated on a real machine as opposed to simulations. The models determine the region in the parameter space where the techniques are most effective, while the measurements determine the region where the applications lie. We find that these regions do not always overlap significantly.The multithreading model shows that only 2-4 contexts are necessary to maximize this technique's potential benefit in current multiprocessors. Multithreading improves execution time by less than 10% for most of the applications that we examined. The model also shows that multithreading can significantly improve the performance of the same applications in multiprocessors with longer latencies. Reducing context-switch overhead is not crucial.The software prefetching model shows that allowing 4 outstanding prefetches is sufficient to achieve most of this technique's potential benefit on current multiprocessors. Prefetching improves performance over a wide range of parameters, and improves execution time by as much as 20-50% even on current multiprocessors. The two models show that prefetching has a significant advantage over multithreading for machines with low memory latencies and/or applications with high cache miss rates because a prefetch instruction consumes less time than a context-switch.
Minimizing completion time of a program by checkpointing and rejuvenation
Authors: Garg Sachin , Huang Yennun , Kintala Chandra , Trivedi Kishor S.
Published: January 2007

Checkpointing with rollback-recovery is a well known technique to reduce the completion time of a program in the presence of failures. While checkpointing is corrective in nature, rejuvenation refers to preventive maintenance of software aimed to reduce unexpected failures mostly resulting from the "aging" phenomenon. In this paper, we show how both these techniques may be used together to further reduce the expected completion time of a program. The idea of using checkpoints to reduce the amount of rollback upon a failure is taken a step further by combining it with rejuvenation. We derive the equations for expected completion time of a program with finite failure free running time for the following three cases when; (a) neither checkpointing nor rejuvenation is employed, (b) only checkpointing is employed, and finally (c) both checkpointing and rejuvenation are employed.We also present numerical results for Weibull failure time distribution for the above three cases and discuss optimal checkpointing and rejuvenation that minimizes the expected completion time. Using the numerical results, some interesting conclusions are drawn about benefits of these techniques in relation to the nature of failure distribution.
An overview of the design and implementation of a large and complex simulation effort
Authors: Fernandez Mark R. , Ellis John W. , Miller James E.
Published: January 2007

As one would anticipate, there is considerable interest within the military community for developing the capability to accurately simulate the behavior of sound in any of the oceans of the world under any of the conditions which might arise there [1,2,3]. With this capability the quality of training could be increased and the associated training costs could be reduced; performance requirements for new systems could be examined under a variety of conditions which include working with all combinations of proposed, prototype, and operational systems functioning in both familiar as well as untested environments; tactics for deploying defenses, searching for an enemy and counter measures against that enemy could be evaluated; the impact of technological advances or the advantages gained through espionage by an enemy force could be evaluated, real and realistic situations could be recreated and thoroughly studied, and finally, the value of better environmental data could be determined prior to allocating both the time and money needed to collect, process, store and distribute that data [4].
Searching symbolically for Ape´ry-like formulae for values of the Riemann zeta function
Authors: Borwein Jonathan , Bradley David
Published: January 2007

We discuss some aspects of the search for identities using computer algebra and symbolic methods. To keep the discussion as concrete as possible, we shall focus on so-called Apéry-like formulae for special values of the Riemann Zeta function. Many of these results are apparently new, and much more work needs to be done before they can be formally proved and properly classified. A first step in this direction can be found in [1].
Transparent incremental state saving in time warp parallel discrete event simulation
Authors: Rönngren Robert , Liljenstam Michael , Ayani Rassul , Montagnat Johan
Published: January 2007

Many systems rely on the ability to rollback (or restore) parts of the system state to undo or recover from undesired or erroneous computations. Examples of such systems include fault tolerant systems with checkpointing, editors with undo capabilities, transaction and data base systems and optimistically synchronized parallel and distributed simulations. An essential part of such systems is the state saving mechanism. It should not only allow efficient state saving, but also support efficient state restoration in case of roll back. Furthermore, it is often a requirement that this mechanism is transparent to the user. In this paper we present a method to implement a transparent incremental state saving mechanism in an optimistically synchronized parallel discrete event simulation system based on the Time Warp mechanism. The usefulness of this approach is demonstrated by simulations of large, detailed, realistic FCA and a DCA-like cellular phone systems.
The
APOSTLE
simulation language
Authors: Wonnacott Paul , Bruce David
Published: January 2007

A simulation-oriented language can significantly enhance the usability of Parallel Discrete Event Simulation (PDES) by hiding the complexities of the synchronization protocol used to ensure that events are processed in the correct order. The higher-level interface presented to the user by such a language also allows optimizations to be performed that are difficult and cumbersome with current parallel simulators, such as granularity control. APOSTLE is a new high-level simulation-oriented language for PDES, and in this paper we report that the APOSTLE granularity control mechanism reduced simulation run-times by as much as 80%. We also report that APOSTLE achieved a parallel speed-up of around 9 on 16 processors relative to its optimized sequential implementation and a parallel speed-up of around 6 on 16 processors relative to MODSIM II. Overall, we believe that the widespread success of PDES can only be achieved using a simulation-oriented language, and that APOSTLE has made a significant contribution towards this goal.
Actor based parallel VHDL simulation using time warp
Authors: Krishnaswamy Venkatram , Banerjee Prithviraj
Published: January 2007

One of the methods used to reduce the time spent simulating VHDL designs is by parallelizing the simulation. In this paper, we describe the implementation of an object-oriented Time Warp simulator for VHDL on an actor based environment. The actor model of computation allows the exploitation of fine grained parallelism in a truly asynchronous manner and allows for the overlap of computation with communication. Some preliminary results obtained by simulating a set of multipliers and some ISCAS benchmark circuits are provided. In addition, the importance of placing processes based on circuit partitioning techniques for improving runtimes and scalability is demonstrated. Results are reported on a Sun SPARCServer 1000 and an Intel Paragon.
Book review: Advances in Genetic Programming edited by Kenneth E. Kinnear, Jr. (The MIT Press 1994)
Authors: Haynes Thomas
Published: January 2007

This collection of papers arose from a genetic programming (GP) workshop at the Fifth International Conference on Genetic Algorithms in 1993. The intended audience is the intermediate practitioner. While both beginner and advanced level papers are present in the book, I believe that someone who is already familiar with the field of genetic programming will get the most benefit from this book. The papers present a good blend of theoretical and experimental topics in GP. This book is also not just intended for academicians, some of the authors hold regular daytime jobs in industry and indulge in GP research only in their free time.
Book review: Genetic Programming I1: Automatic Discovery of Reusable Programs by John R. Koza (The MIT Press 1994)
Authors: Haynes Thomas
Published: January 2007

This book is a followon to the book in which John Koza introduced genetic programming (GP) to the world
"enetic Programming: On the Programming of Computers by Means of Natural Selection"
[5]
1
. As such, the primary intended audience is someone already familiar with GP; however, Koza does provide introductory material to both genetic algorithms (GA) and GP. The driving force behind this book is a method to automatically decompose a program into solvable components. The book presents this method, called automatically defined functions (ADF), and then presents case studies of the application of this method to a variety of problems. While this book's size is intimidating, there is a wealth of information to be found by the reader willing to conduct a prolonged campaign. The reader is advised to study the first seven chapters of the book to gain an understanding of the concepts behind ADFs. Then the reader should be able to select which case studies he or she finds to be of interest. If the reader is feeling overwhelmed by the information presented in the book, there are several concise chapters dealing with ADFs by Koza and others in
Advances in Genetic Programming
edited by Kenneth Kinnear [3]
2
.
Book review: The Artificial Life Route to Artificial Intelligence: Building Embodied, Situated Agents edited by Luc Steels (Lawrence Earlbaum, New Jersey)
Authors: Rubin Stuart
Published: January 2007

The book, "The Artificial Life Route to Artificial Intelligence," edited by Luc Steels and Rodney Brooks follows from a workshop held in April of 1991 in the old Priory of Corsendonck, north of Brussels. The workshop was organized by Luc Steels and Rodney Brooks and sponsored by NATO and MIT. The participants were Rodney Brooks, William Clancey, John Hallam, Stevan Harnad, Leslie Kaelbling, Chris Langton, Maja Mataric, Rolf Pfeifer, Tim Smithers, Luc Steels, Charles Taylor, Francis Van Aeken, and Francisco Varela. The purpose of this workshop was to explore a new paradigm in AI, one that is predominantly bottom-up in nature: exploiting intelligent autonomous agents.
Book review: Case-Based Reasoning in Design by Mary Lou Maher, M. Bala Balachandran, and Dong Mei Zhang (Lawrence Erlbaum Associates, 1995)
Authors: Wolverton Michael
Published: January 2007

Developing computer programs that support the design process has long been an area of study in Artificial Intelligence. Theorem provers, rule-based expert systems, and constraint satisfaction programs have been popular platforms with which to support design since almost the beginning of AI/design research, and more recently analogical or case-based reasoning have shown promise as a substitute for or a complement to those and other technologies. In their new book, Maher, Balachandran, and Zhang give an in-depth look at this newer topic of research---incorporating case-based reasoning in design support programs. The authors, all current or former researchers at the University of Sydney's Key Centre of Design Computing, focus on their own research in the area, describing the techniques for case representation, case recall, and case adaptation they have developed for design, and presenting implemented systems that use these techniques to support design.
Computing radical expressions for roots of unity
Authors: Weber Andreas
Published: January 2007

We present an improvement of an algorithm given by G
AUSS
to compute a radical expression for a
p
-th root of unity. The time complexity of the algorithm is
O
(
p
3
m
6
log
p
), where
m
is the largest prime factor of
p
- 1.On current workstations the given implementation of the algorithm can be used to obtain radical expressions for
p
-th roots of unity for
p
up to about 100 in the general case and
p
up to about 250 if
p
- 1 has only small prime factors.Moreover, the algorithm allows the use of coarse grained parallel computation in various ways that would allow one to compute bigger examples on a network of workstations.
MPC++ approach to parallel computing environment
Authors: Ishikawa Yutaka
Published: January 2007

MPG++ is an extension of C++, which supports control parallel programming and metalevel programming. The MPG++ metalevel programming facility enables users to extend or modify C++ language features. Library designers may supply abstractions in MPG++ source files where those abstractions are defined by the MPG++ metalevel programming facility. The users can use the right abstractions for their demands by just including files in their source files.
On parallel object oriented programming in Fortran 90
Authors: Norton Charles D. , Decyk Viktor K. , Szymanski Boleslaw K.
Published: January 2007

The C++ programming language [6, 10] is well-known for its support of object oriented concepts, useful in abstraction modeling. Containing many important features, its popularity is growing with a new generation of scientists anxious to bring clarity and flexibility to their programming efforts. Nevertheless, most of the scientific applications in development and use today are based on Fortran, the most popular language for scientific programming.Fortran is not a static language, it has continually evolved to include the most recent proven ideas and concepts garnered from other programming languages. Until recently, many of the most modern features were not available, complicating abstraction modeling for large scale development projects. This can make software difficult to comprehend, unsafe and potentially useless. The emergence of Fortran 90 [3] has dramatically changed the prospects of Fortran programming. Not only are many of the most modern aspects of programming language techniques included in the standard, there are also specific new additions that will undoubtedly affect the next generation of all languages used in scientific programming [8].
Presentation of images for the blind
Authors: Ina Satoshi
Published: January 2007

This paper introduces a method on how to present natural color photographs or scenes to the blind. In our system original photographs or scenes are taken in computer's memory through image scanner or video camera as digital images, which are image-processed and translated into tactile images on Braille paper. We applied some image-processes to original images to simplify them by extracting some attributes from them. These image-processed images are transformed into final tactile images, which are to be easy to understand for the blind. We show some examples of image-processes and tactile images.
Focusing attention in anytime decision-theoretic planning
Authors: Haddawy Peter
Published: January 2007

Any anytime algorithm used for decision-making should have the property that it considers the most important aspects of the decision problem first. In this way, the algorithm can first eliminate disastrous decisions and recognize particularly advantageous decisions, considering finer details if time permits. We view planning as a decision-making process and discuss the design of anytime algorithms for decision-theoretic planning. In particular, we present an anytime decision-theoretic planning algorithm that uses abstraction to focus attention first on those aspects of a planning problem that have the highest impact on expected utility. We discuss control schemes for refining this behavior and methods for automatically creating good abstractions.
Value-density algorithms for the deliberation-scheduling problem
Authors: Ronén Yagíl , Mossé Daniel , Pollack Martha E.
Published: January 2007

Several disciplines such as real-time artificial intelligence, operating systems, operations research, and local area networks have addressed problems of scheduling tasks with timing and precedence constraints. In this paper, we compare the different value-density algorithms, and suggest a novel algorithm that subsumes the previous ones with respect to schedulability. We assess the application of these various algorithms to the
deliberation scheduling problem
for autonomous agents.
On state-space abstraction for anytime evaluation of Bayesian networks
Authors: Liu Chao-Lin , Wellman Michael P.
Published: January 2007

Despite the increasing popularity of Bayesian networks for representing and reasoning about uncertain situations, the complexity of inference in this formalism remains a significant concern. A viable approach to relieving the problem is trading off accuracy for computational efficiency. To this end, varying the granularity of state space of state variables appears to be a feasible strategy for controlling the evaluation process. We consider an anytime procedure for approximate evaluation of Bayesian networks based on this idea. On application to some simple networks, the procedure exhibits a smooth improvement in approximation quality as computation time increases. With the aim of developing principled control techniques, we also conduct a theoretical analysis of the quality of approximation. Our main result demonstrates that the error induced by state-space abstraction deceases with the distance from the abstracted nodes, where "distance" is defined in terms of d-separation. While the empirical results suggest that incremental state-space abstraction offers a viable performance profile, the theoretical results represent a starting point for the deliberation scheduling of our anytime approximation method.
The modeling and simulation academic infrastructure
Authors: Rogers Ralph V.
Published: January 2007

The increasing success and promise simulation methodologies and technologies in meeting the challenges confronting industry, government, military and education have created unprecedented demand for skilled simulation professional. Finding simulation professionals, however, has been difficult due primarily to the lack of an adequate academic infrastructure for simulation education. As this infrastructure develops, questions concerning the design and directions for curriculum design and content. The University of Central Florida's Simulation Systems Masters of Science programs provide over a decade of experience in coping with these questions. They also provide source of lessons learned and perspectives for continued developed of the simulation academic infrastructure.
Solving algebraic systems using matrix computations
Authors: Manocha Dinesh , Krishnan Shankar
Published: January 2007

Finding zeros of algebraic sets is a fundamental problem in scientific and geometric computation. It arises in symbolic and numeric techniques used to manipulate sets of polynomial equations. In this paper, we outline algorithms and applications for solving zero and one dimensional algebraic sets using matrix computations. These algorithms make use of techniques from elimination theory and reduce the problem to finding singular sets of matrix polynomials. We make use of algorithms for eigen-decomposition, singular value decomposition and Gaussian elimination to compute the singular sets. These algorithms have been implemented and perform very well in practice. We describe their application to computing conformations of molecular chains, inverse kinematics of serial robots, solid modeling and manufacturing.
The career dynamics of information systems professionals
Authors: McLean Ephraim R. , Smits Stanley J. , Tanner John R.
Published: January 2007

A concern of many information systems (I/S) managers is the ability to attract, retain, and motivate their I/S professional staff, particularly those who have the potential to be high performers. However, many of the attitudes and attributes of these newly-hired employees are formed prior to entering the workplace; they are shaped by the students' college studies and by their personal backgrounds and characteristics.This study investigates the career progression of nearly a thousand I/S majors from 38 colleges and universities who have been tracked over several years as they complete their college studies and move into their first I/S jobs. It examines three aspects of this progression: career preparation and entry; work adjustment; and career outlook, both at present and long-term. A number of key variables are identified, derived both from theory and from the empirical results of the study. In particular, the balance between developing technical skills and "people" skills as individuals move through the early stages of their careers is given special attention.
Do you have the partners you need to survive
Authors: Creth Sheila D.
Published: January 2007

I am pleased to be invited to speak on the issue of partnerships and collaboration between information specialists, librarians and computer/technology specialists. Over the past several years, I have indeed given considerable thought and time on just this issue through work on my campus and in the national arena within CNI & Educom. There are many opportunities that exist but also many sink holes that await us both in ignoring these opportunities AND in pursuing them. I believe that our two professionals groups - library and computing professionals - have a significant leadership role to play and contributions to make in our respective institutions and that these contributions will be that much greater if we work together rather than separately.
The growing of a cyberspace at Spanish National Open University (UNED)
Authors: Medina Jose Collado
Published: January 2007

As professor at the UNED (Spanish National Open University) Economics Faculty, and as consultative member of the Computing Commission of the Faculty, I am involved in planning and starting a new cyberspace site.