bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge-level analysis of planning systems
Authors: Valente André
Published: January 2007

Planning is one of the most important and oldest fields of AI. However, there is no consensus on how to compare and classify planning systems and methods. Neither the traditional view of planning as search nor the formalization efforts have been able to provide a basis for a classification scheme.This article explores the idea that a perspective based on Newell's knowledge level can be useful for this task. We present a knowledge-level analysis of classical planning systems in terms of models of the problem-solving methods they used. Rather than reengineering these systems in detail, however, our goal is to show how this type of analysis can help define which roles knowledge may play in planning tasks, and how these roles can be used to compare planning methods in terms of (i) which types of knowledge are used, (ii) how they are structured in what we call
domain models.
As a tool to analyze and represent planning methods we use the KADS methodology.
HalClon
Authors: Crow Daniel
Published: January 2007

This short paper discusses some early work on the HalCIon project. The objective of this project is to develop an educational hypermedia CD-ROM teaching principles and practices of Human-Computer Interaction to a commercial audience.
SIERRA
Authors: Vanderdonckt Jean
Published: January 2007

This short paper discusses some early work on the SIERRA (Système Interactif pour l'ERgonomie de Réalisation d'Applications - An Interactive System for Ergonomic Realization of Applications) tool for managing guidelines. The goal of this tool is to develop a hypermedia system managing guidelines, human-computer principles.
Book Review: Cost Justifying Usability
Authors: Wixon Dennis
Published: January 2007

Bias and Mayhew and their contributing authors provide a comprehensive overview of cost justification methods applied to human computer interaction. The book is replete with worked detailed examples and specific case studies. The book also presents a broader perspective of the development of usability in an organization. This broader perspective balances the relatively precise focus of a cost benefit analysis in a particular project. Overall, the book represents an important milestone in the evolution of user interface design. That evolution has taken us from a collection of well founded and simple principles (Gould and Lewis 1985) to a wide variety of detailed methodologies (Nielsen, 1993, 1994). In addition, the place of usability in design has evolved from an interesting footnote to a key role in the success of any development effort. As we ask the development community to stretch their thinking and work practice to include usability, we need to be ready to stretch our thinking and work practice to include the broader business and cultural context in which we operate. This book represents an important milestone in our individual and collective growth.This review covers the audience and goals of the book, the content of the chapters, and an overall assessment.
Book review: The Art of the Metaobject Protocol by Gregor Kiczales, Jim des Rivieres, and Daniel G. Bobrow (MIT Press, 1991) and Object-Oriented Programming: The CLOS Perspective Edited by Andreas Paepcke (MIT Press, 1993)
Authors: Miller Granville G. , Znayenko Zina
Published: January 2007

Yielding the "best" possible performance from a given design may impact an application's viability. In a competitive software application market, performance analysis using benchmarks may set one vendor ahead of the others. In "real-time" systems, performance optimizations may be critical to achieving "deadlines", points in time in which processing must be completed. Even in computer systems that do not fall into either category, a faster system is often preferable to a slower one.
The ultimate bead counter
Authors: Lubachevsky Boris D. , Privman Vladimir , Roy Subhas C.
Published: January 2007

We simulate ballistic particle deposition wherein a large number of spherical particles are “dropped” vertically over a planar horizontal surface. Upon first contact (with the surface or with a previously deposited particle) each particle stops. This model helps material scientists to study the adsorption and sediment formation [1]. The model is sequential, with particles deposited one by one. We have found an equivalent formulation using a continuous time random process and we simulate the latter in parallel using a method similar to the one previously employed for simulating Ising spins [2]. We augment the parallel algorithm for simulating Ising spins with several techniques aimed at the increase of efficiency of producing the particle configuration and statistics collection. Some of these techniques are similar to [3], [4], [5]. We implement the resulting algorithm on a 16K PE MasPar MP-1 and a 4K PE MasPar MP-2. The parallel code runs on MasPar computers two orders of magnitude faster than an optimized sequential code runs on a fast workstation.
Security in a networked environment
Authors: Angaye Cleopas O.
Published: January 2007

Networking allows multiple users to share data, information, software, and hardware. In addition, a network can centralize the management of a large base of connected processing units often configured to provide one location for coordinating security, backup and control. Security is the means to limit damage to data and to prevent user access to unauthorized information. The question of maintaining adequate security provisions across heterogenous platforms presents new security challenges for the network administrator. Computer crimes are on the rise. These crimes range from eavesdropping confidential information to physicial damage of equipments that information is stored. Some reasons of the increase in computer crimes include that there are more computers in use, there are more networks, and PCs can now access larger mainframe databases.
A poor man's access to laser printing facilities
Authors: Wu Albert K. W.
Published: January 2007

This article describes a simple and cheap method to allow various heterogeneous non-interlinked systems to access expensive laser printer facilities. Basically it is a software approach with the different systems print outputs redirected to a centralized system for spooling and printing services.
On formal models for object-oriented databases
Authors: Vossen Gottfried
Published: January 2007

While object-oriented database management systems are already arriving in the marketplace, their formal foundations are still under development. In this paper, one central aspect of such foundations,
formal models
for object-oriented databases, is considered. It is discussed why a formal model is desirable, what it is supposed to comprise in this context (a structural as well as a behavioral part), and how this can be achieved; to this end, the central ingredients which are shared by many proposed models are presented in some detail. This carries over to design issues for database descriptions in an object-oriented model, for which two distinct strategies are outlined. Finally, the question is discussed whether the modeling concepts described are indeed the ones that the applications which originally triggered the merger of database technology with object-oriented concepts need. Our argument is that this is only partially the case, and two promising directions for future work are sketched.
A note concerning
proof processor animation with SIMAN
Authors: McHaney Roger , White Doug
Published: January 2007

The purpose of this note is to clarify statements made about Proof Animation's built-in drawing tool and its potential to recreate complex systems' layouts. The article, Proof Processor Animation With SIMAN (McHaney and White, 1994), was in no way meant to disparage Proof Animation or its capabilities. Several references to difficulty in development of a 'high-quality' animation layout failed to mention the development for this project was undertaken using the student edition of Proof. The student edition has been provided by Wolverine Software Corporation as an educational and instructional tool. It is in no way intended to facilitate complicated development efforts. In order to make the student edition of Proof more affordable, several features found in the full version have been left out. These include (Wolverine Software Corporation, 1992, p. 11):1) Animation Trace File Limited to 1250 Lines2) Layout Files Larger than 12500 Bytes Cannot Be Read3) Execution Stops after 2 Minutes
User interface design and HCI
Authors: Howard Steve
Published: January 2007

Though many published curricula in HCI now exist, little has been done to map those curricula onto the needs of user interface designers. This paper reports such an attempt. A number of published curricula in HCI were synthesised into a checklist of 'things a users interface designer might need to know'. The checklist was then used as the basis of a series of structured interviews with practising user interface designers. Essentially, each designer was asked if they 'needed to know about each item on the checklist in order to do their job?'. The results, interesting and sometimes surprising, suggest that whilst knowledge of some aspects of published curricula (e.g. user interface technology and design techniques) is considered vital to the practice of interface design, knowledge of other components (e.g. psychological foundations of the user) is required for other than straightforward or practical reasons. The implications of this and other findings for curricula, and education in general, is discussed.
Finding and reminding
Authors: Barreau Deborah , Nardi Bonnie A.
Published: January 2007

This paper summarizes and synthesizes two independent studies of the ways users organize and find files on their computers. The first study (Barreau 1995) investigated information organization practices among users of DOS, Windows and OS/2. The second study (Nardi, Anderson and Erickson 1995), examined the finding and filing practices of Macintosh users. There were more similarities in the two studies than differences. Users in both studies (1) preferred location-based finding because of its crucial reminding function; (2) avoided elaborate filing schemes; (3) archived relatively little information; and (4) worked with three types of information: ephemeral, working and archived. A main difference between the study populations was that the Macintosh users used subdirectories to organize information and the DOS users did not.
Book review: Subsymbolic Natural Language Processing: An Integrated Model of Scripts, Lexicon, and Memory by Risto Miikkulainen (Bradford Books, MIT Press 1993)
Authors: Lee Changsin
Published: January 2007

The book describes a connectionist natural language processing system that is designed to process script-based narratives: DISCERN (DIstributed SCript processing and Episodic memoRy Network). At first blush, scripts and a connectionist network might look like a strange association. Scripts, which have various 'slots', or 'roles,' for stereotypical events and objects involved in routine activities, are used as data structures by Schank and Abelson (1977) because of their psychological plausibility in organizing experiences. 'Structures', the Achilles' heel for connectionism in natural language. The lack of internal structures in connectionist networks results in their incompetence in handling natural language which is systematic and productive, as Fodor and Pylyshyn (1988) emphatically argue. Furthermore, the fact that natural language is sequential puts another onerous burden on homogeneous connectionist networks which are basically simple pattern matching mechanisms.
Individual-user-centered facilities for improving digital library application productivities on the Internet
Authors: Shen Stewart N. T.
Published: January 2007

We have been exploring ways to increase the productivity of digital library applications over the Internet.
On controlling the presentation of information
Authors: Pike Geoffrey
Published: January 2007

One's right to read a newspaper in any conceivable idiosyncratic manner is not questioned. For historical reasons, many people are blind to this right when it comes to other media, such as television, radio, and the World Wide Web. When a signal is transmitted freely, accompanied by begging that people tune in, it seems untenable to charge viewers with copyright violations if they look at the signal, or portions thereof. "Rebroadcasting" is illegal, but anything that happens between legally acquiring information and privately viewing that information is harmless.
Your local newspaper
Authors: Kingery B. David
Published: January 2007

The current research in digital libraries focuses on the academic and research communities with good reason. However, there are other communities of users which need to be supported. One of these communities includes the producers and consumers of newspapers. The local newspaper publisher produces a product which contains information targeted for a specific market. By providing news of local interest, the newspaper publisher creates a specialized collection of text and photographs. It is this "localized" collection that is the focus of this paper. Will the local newspaper, in its electronic form, be relegated to content within the community's digital library? Or can the newspaper publisher transform the traditional paper-and-ink offering into a digital product that can stand alone as its own digital library?
User modeling in UC, the UNIX consultant
Authors: Chin D. N.
Published: January 2007

UC is a natural language computer consultant system for the UNIX operating system. The user model in UC encodes the user's knowledge state and allows UC to tailor its responses to the user. The model encodes apriori knowledge in a double stereotype system that is extremely efficient. Models of individual users are updated dynamically and build on top of the user's stereotype. The model deals with uncertainty in apriori information and attempts to deduce the user's level during the course of a session.
Comparison of elderly and younger users on keyboard and voice input computer-based composition tasks
Authors: Ogozalek V. , Van Praag J.
Published: January 2007

An experiment was run in which elderly and younger people used a keyboard editor and a simulated listening typewriter to compose letters. Performance was measured and participants rated the systems used.

Our general conclusions were as follows:

There are no major differences in performance between elderly computer users and their younger counterparts in carrying out a computer-based composition task.

Elders appear to be more enthusiastic users of computer systems than are younger people. This is shown by preference ratings, behavioral observations, and post-experimental debriefings.

Voice input does not improve performance on composition tasks, but it is greatly preferred over the traditional keyboard input method.
Relief characters by micro capsule paper
Authors: Ohtake Nobuyuki , Ogawa Yasuhiko , Yonezawa Yoshimichi
Published: January 2007

Micro capsule paper has been developed by Yonezawa [6, 7] for tactile pattern. To learn printed Chinese characters (called "Kanji" in Japanese), several relief characters have been prepared to enable the blind to study these complicated printed characters by this micro capsule paper. All prepared characters (alphabet, braille patterns, Kanji) data for micro capsule paper are converted PostScript language[1] by a developed tool. Although this matter has been thought of a local topic in Kanji cultural area, hidden problems containing some common subjects exist in all forms of written language. There are several communication tools (braille, telephone, audio equipments, etc…) for the blind, especially Optacon (optical to tactile converter) is one of a few equipment which reads visual information. To realize the original printed characters is an essential matter when the blind use the Optacon. In any case, people who do not have basic knowledge about printed characters can not understand anything. And it is important for the blind to understand written language, so original character learning is a matter of great essentials. However learning Kanji characters is a Japanese problem, the research and discussion in this paper also contain practical applications and common problems for other written language.
Acknowledgment
Authors: Smith John W.
Published: January 2007

This series of articles is derived from real-world, in-the-trenches experience. Although the expression and presentation, and all the fault thereof, is mine, the basic ideas come from my interactions with a wide range of people and cultures. I would like to specifically acknowledge two institutions and two colleagues.
Assessing the impact of time on user interface design
Authors: Johnson Chris , Gray Philip
Published: January 2007

Temporal properties of interaction have a profound impact upon the usability of human computer interfaces. Delays in response time can lead to frustration and error. The simultaneous presentation of many different pieces of information imposes heavy demands upon the cognitive and perceptual resources of system operators. These problems have been investigated by a number of recent research initiatives. Unfortunately, it has been difficult to replicate the results that have been obtained from experimental investigations. This creates significant problems for designers if these results are to guide the future development of interactive systems. This paper briefly describes how an multi-disciplinary team has addressed this problem during the Temporal Aspects of Usability (TAU) project.
Time modelling in Petri nets for the design of interaction active
Authors: Palanque Philippe , Bastide Rémi
Published: January 2007

This paper addresses the problem of the representation of time in interactive software models. We aim at providing solutions allowing the software designers to efficiently use time modelling during the design process, and to check that the software being built actually corresponds to the temporal requirements. The modelling approach makes a precise distinction between qualitative and quantitative time modelling. The qualitative aspects are presented according to basic constructs of Petri nets while quantitative aspects are introduced according to several extensions to the basic constructs of Petri nets. Each of those constructs is presented on a simple example.
A modular approach to real-time synchronization
Authors: Saito Masahiko , Agha Gul A.
Published: January 2007

In this paper, we discuss real-time barrier synchronization as an example of timing constraints on synchronization. Real-time barrier synchronization is constrained by two timing values: earliest release time and release time skew. Earliest release time is the delay from the time when the last object participating in barrier synchronization issues a barrier operation, till when one of the participating objects resumes its method. Release time skew is the delay between the first and the last resumption times of objects. The implementation of real-time barrier synchronization consists of a negotiation phase and a scheduling phase. In the negotiation phase, all the participating objects communicate with one another and agree on the time when they are going to resume their method execution. Local scheduling at individual nodes must then ensure that the agreement is implemented. Thus, earliest release time and release time skew are defined by the procedures of the negotiation and the scheduling phase, respectively. We describe an architecture which enables the implementation of real-time barrier synchronization in a distributed system with unreliable channels.
The validation and implementation of real-time robotics systems using Cleopatra object-oriented physically-correct specifications
Authors: Bestavros Azer
Published: January 2007

The specification of a real-time system is often the result of a process, whereby a conceptual control system is fleshed out as a computer program. To be accurate, this process must preserve important causal and structural properties of the control system. For example, if the control system has multiple functional components operating concurrently, then the process of mapping these components into a computer program executing on a single processor, must ensure that these components do not interact in ways that are physically impossible. In this paper we review our work on CLEOPATRA, an object oriented specification and programming language that restricts expressiveness in a way that allows the specification of only reactive, spontaneous, and causal computation. Unrealistic systems---possessing properties such as infinite capacities or perfect timing---cannot even be specified. We argue that this "ounce of prevention" at the specification level is likely to spare a lot of time and energy in the development cycle---not to mention the elimination of potential hazards that would have gone unnoticed.
Object-oriented development of real-time systems
Authors: Browne J. C.
Published: January 2007

There are many benefits claimed for the use of object-oriented software development methods, and in particular object-oriented analysis methods for software development. The benefits which are cited typically include.a. An understandable and maintainable system structure.b. Clean partitioning which allows the system to evolve as technology changes.c. Enhanced potential for reuse of components.
A metrics-driven approach for utilizing concurrency in object-oriented real-time systems
Authors: Welch Lonnie R.
Published: January 2007

This paper presents a metrics-driven process and software toolset for the engineering of concurrent, object-oriented, real-time systems. In the engineering of real-time systems, the objective need not be to exploit all potential concurrency, but to exploit only as much concurrency as is needed to enable satisfaction of timing constraints. Thus, the systems engineering process presented in the paper utilizes inter-object concurrency selectively, as a means to meet timelines. To support the selective use of concurrency, this paper describes techniques for computing inter-object concurrency metrics. It is also shown how the concurrency metrics are used to guide the mapping of objects onto processors.
A workload characterization study of Internet Web servers
Authors: Arlitt Martin F. , Williamson Carey L.
Published: January 2007

This paper presents a workload characterization study for Internet Web servers. Six different data sets are used in this study: three from academic environments, two from scientific research organizations, and one from a commercial Internet provider. Throughout the study, emphasis is placed on finding workload
invariants
: observations that apply, or seem to apply, across all the data sets studied. Ten invariants are identified. These invariants are deemed important since they potentially represent universal truths for all Internet Web servers.
CD-ROM/WWW technology
Authors: Hagler Marion , Marcy William M. , Yeargan Jerry R.
Published: January 2007

In the last quarter of 1996, the IEEE Transactions on Education will publish a special issue, accompanied by a CD-ROM organized essentially as a World Wide Web (WWW) server so that it can be viewed with browsers on any of the three major desktop hardware platforms. This paper discusses (1) how the combination of CD-ROM technology and the WWW de facto file format standards open the possibility for archiving multimedia and software and (2) how the WWW has permitted experimentation with a paperless review process.
Conformational statistics of the nitrogen linkage in glycopeptides using umbrella sampling
Authors: Duben Anthony J.
Published: January 2007

The conformational statistics of the glycosylated dipeptide N - acetyl - δ - N - (2 - acetamido - β - D - glucopyranosyl) - L - asparaginyl - N' - methyl amide (glcNAc-Asn), a model of N-linked glycopeptides, was determined using umbrella sampling. The use of umbrella sampling allowed the importance sampling algorithm to accept new conformations with probabilities exceeding 40%. The satisfactory acceptance rate generated a chain of conformations and a set of properties suitable for comparison with available experimental results. Comparison of calculated structures for glcNAc-Asn with those determined experimentally by NMR, circular dichroism spectroscopy, and X-ray crystallography showed that the Momany-Scheraga conformation energy (ECEPP) over-emphasized non-bonded repulsions. Based on the experimentally determined structures, an effective two-fold potential barrier was imposed on the anomeric linkage. Predictions based on conformational statistics were sensitive to the choice of a three-fold or two-fold torsional barrier at the anomeric linkage.
Identifying and testing of signatures for non-volatile biomolecules using tandem mass spectra
Authors: Hashemi Ray R. , Schafer Theresa M. , Hinson William G. , Lay Jackson O.
Published: January 2007

Identification of volatile and semi-volatile molecules using traditional electron ionization mass spectrometry has been successful. The major contributor to this success is the reproduceability of the mass spectra, which allow identification of components based on comparison of fragmentation patterns within very large databases. However, this approach is not useful for the identification of typical nonvolatile biomolecules. Tandem mass spectrometry with collision induced dissociation (CID) has the potential to provide structure-specific fragmentation from non-volatile biomolecules.The recognition of these molecules based on CID is not an easy task, since the spectra generated for a given molecule are not as reproducible as in traditional electron ionization mass spectrometry. Also, the rules governing the formation of CID produced ions are not completely understood.In this study we investigate the use of the Kohonen Self-Organized Mapping (SOM) neural network to generate and test signatures (fragmentation patterns) for a given set of non-volatile biomolecules using spectra generated by tandem mass spectrometry with CID. The signatures then may be used as a discriminator for identifying unknown non-volatile biomolecules.
Book review: Artificial Intelligence in Perspective by Daniel G. Bobrow (Ed.) (The MIT Press 1993)
Authors: Roy Rajkumar , Bapi Raju S.
Published: January 2007

The past and present of Artificial Intelligence have been nicely presented in the book, "Artificial Intelligence in Perspective". This book is dedicated to Allen Newell, one of the founders of artificial intelligence (AI). The book looks at the achievements of AI between 1971 and 1986 and examines their present relevance. The editor had invited about thirty authors whose papers had been heavily cited to write commentary on the impact and relevance of their original work from a contemporary perspective. The second part of the book consists of several reviews of Newell's book, "Unified Theories of Cognition." Two of his research collaborators responded to the issues raised by the reviewers. The book ends with an interview with Newell. The book covers a wide range of issues (making it a good reference), points to some unsolved problems in AI, and raises some new issues. It is relevant for researchers in AI, postgraduate students and AI practitioners.
Collective learning and collective memory for coping with dynamic complexity
Authors: Wærn Yvonne
Published: January 2007

The need for coping with dynamic complex situations cuts through most modern life. Examples of such situations are emergency management, military command and control, traffic control (air, rail, road, water), rescue services, grid control, intensive care and industrial plant control. Consequences of failures in such situations include uncontrolled releases, injuries, poisoning and single deaths, all of which are highly desirable to prevent.Efficient performance in coping with dynamic situations is dependent on people's ability to notice, diagnose and react appropriately to the situation as well as their ability to combine and coordinate their perceptions, interpretations and actions. People are most efficient when their actions are so well trained that they can be performed automatically. People also have the ability to draw upon similar experiences and to reconfigure actions, in short, to be flexible and creative. (By creative is here meant the ability to come up with new and relevant solutions). This ability is related to their reflective actions, which are slow in comparison to the automated ones. Efficiency and creativity are both needed in complex dynamic situations. Both rely upon experience, skill and knowledge. The present workshop aims at discussing how efficiency and creativity in collaborative coping with complex dynamic situations can be learnt and trained as well as supported by information technology.This workshop was proposed by a group of European researchers, working on a project under COST 14, Cooperation Technology. We wanted to share our problems and ideas with other people, both within and outside of Europe.
Speeding up Lisp-based symbolic mathematics
Authors: Fateman Richard J. , Hayden Mark
Published: January 2007

Two techniques for speeding up a traditional Lisp-based symbolic manipulation system (Macsyma) were outlined in a previous paper [2]. These were: using unique representations for equivalent "kernel" expressions (where a kernel here is basically anything but a sum), and using hash tables for an unordered representation of sums. New tests in the context of a complete version of Macsyma suggest that a speedup of --- in some cases --- orders of magnitude can be obtained. In some cases this appears to match or exceed the speed of Mathematica, a recently written system written in a lower-level language (e.g. C).
Web server workload characterization
Authors: Arlitt Martin F. , Williamson Carey L.
Published: January 2007

The phenomenal growth in popularity of the World Wide Web (WWW, or the Web) has made WWW traffic the largest contributor to packet and byte traffic on the NSFNET backbone. This growth has triggered recent research aimed at reducing the volume of network traffic produced by Web clients and servers, by using caching, and reducing the latency for WWW users, by using improved protocols for Web interaction.Fundamental to the goal of improving WWW performance is an understanding of WWW workloads. This paper presents a workload characterization study for Internet Web servers. Six different data sets are used in this study: three from academic (i.e., university) environments, two from scientific research organizations, and one from a commercial Internet provider. These data sets represent three different orders of magnitude in server activity, and two different orders of magnitude in time duration, ranging from one week of activity to one year of activity.Throughout the study, emphasis is placed on finding workload
invariants
: observations that apply across all the data sets studied. Ten invariants are identified. These invariants are deemed important since they (potentially) represent universal truths for all Internet Web servers. The paper concludes with a discussion of caching and performance issues, using the invariants to suggest performance enhancements that seem most promising for Internet Web servers.
Multiple-valued complex functions and computer algebra
Authors: Aslaksen Helmer
Published: January 2007

I recently taught a course on complex analysis. That forced me to think more carefully about branches. Being interested in computer algebra, it was only natural that I wanted to see how such programs dealt with these problems. I was also inspired by a paper by Stoutemyer ([3]).While programs like Derive, Maple, Mathematica and Reduce are very powerful, they also have their fair share of problems. In particular, branches are somewhat of an Achilles' heel for them. As is well-known, the complex logarithm function is properly defined as a multiple-valued function. And since the general power and exponential functions are defined in terms of the logarithm function, they are also multiple valued. But for actual computations, we need to make them single valued, which we do by choosing a branch. In Section 2, we will consider some transformation rules for branches of multiple-valued complex functions in painstaking detail.The purpose of this short article is not to do a comprehensive comparative study of different computer algebra system. (For an attempt at that, see [4].) My goal is simply to make the readers aware of some of the problems, and to encourage the readers to sit down and experiment with their favourite programs.I would like to thank Willi-Hans Steeb and Michael Wester for helpful comments.
The unwinding number
Authors: Corless Robert M. , Jeffrey David J.
Published: January 2007

From the Oxford English Dictionary we find that
to unwind
can mean "to become free from a convoluted state". Further down we find the quotation "The solution of all knots, and unwinding of all intricacies", from H. Brooke (The Fool of Quality, 1809). While we do not promise that the unwinding number, defined below, will solve
all
intricacies, we do show that it may help for quite a few problems.Our original interest in this area came from a problem in which an early version of D
ERIVE
was computing the wrong answer when simplifying sin(sin
-1
z
), which should always be just
z.
For
z
> 1, D
ERIVE
was getting -
z
as the answer. This bug has of course long since been fixed.What was happening was that in order to improve internal efficiency, all the inverse trig functions were represented as arctangents. Consulting an elementary book of tables, one finds the identitysin
-1
z
= tan
-1
(
z
/√1 -
z
2
). (1)In the same vein, one finds thatsin(tan
-1
w
) =
w
/√1 +
w
2
. (2)Substituting equations (1) and (2) into sin(sin
-1
z
) and simplifying, we get
z
/√1 -
z
2
1/√1/1 -
z
2
, (3)which D
ERIVE
quite properly refused to simplify to
z,
because this is
not
always equal to
z
(see [2]).The fix in this case was to replace equation (2) withsin(tan
-1
w
) =
w
√1/1 +
w
2
. (4)which differs from the original only on the branch cut. See [7] for more discussion. This change allows the simplification of sin(sin
-1
z
) to
z.
Verifying that this approach worked, and indeed trying to understand the problem to begin with, led us to attempt various definitions of a 'branch function'. This introductory problem turned out to be the tip of an iceberg of problems connected with using the principal branch of multivalued elementary functions.
Book review: Empirical Methods for Artificial Intelligence by Paul R. Cohen (The MIT Press, 1995)
Authors: Holte Robert C.
Published: January 2007

This book fills a long-standing void on the bookshelves of AI researchers. It provides practical guidelines on how to conduct empirical research in AI. Although I've been doing experimental AI for almost a decade, I learned a great deal from Cohen's book and I expect I'll refer to it often in the coming years.
The causal Markov condition, fact or artifact?
Authors: Lemmer John F.
Published: January 2007

This paper provides
a priori
cirteria for determing when a causal model is sufficiently complete to be considered a Bayesian Network, and a new representation for Bayesian Networks shown to be more computationally efficient in a wide range of circumstances than current representations.Expert Systems for domains in which uncertainty plays a major role are often built from causal models. These models are usually
implemented
using Baysesian Network technology under the often tacit assumption that a causal model
is
a satisfactory Bayesian Network of the domain. If the system produces unsatisfactory results, the causal model is usually deemed inadequate, probably containing insufficient detail.The assumption that a causal model is an
appropriate
Bayesian Network model is justified by invoking the so called "Causal Markov Condition". In this paper we argue that in many cases it is not the inadequacy of the causal model which produces unsatisfactory results, but rather the inappropriateness of the Causal Markov Condition itself.In this paper we introduce a new functional model of causality, the Communicating Causal Process model, and analyze the appropriatenss of the Causal Markov Condition in light of this model. This analysis yelds domain based
a priori
criteria for judging when the Causal Markov Condition does or does not hold, and when a Causal Model is sufficiently detailed that it can be considered a Bayesian Network.The Communicating Causal Process model also provides the basis for a new representation of Bayes Networks which shown to be more computationally efficient than current representations.
Range partition adaptors
Authors: Austern Matthew H. , Towle Ross A. , Stepanov Alexander A.
Published: January 2007

Range partition adaptors, a new type of adaptor for the C++ Standard Template Library (STL), can be the basis for a parallel version of the STL.
HPC++ and the Europa call reification model
Authors: Gannon Dennis , Diwan Shridar , Johnson Elizabeth
Published: January 2007

HPC++ is a set of parallel programming tools that have been designed by the High Performance C++ Consortium. It consists of a modest set of compiler directives and a parallel extension to the C++ Standard Template Library (STL). In this short note we consider the problem of mixing the parallel STL model with the call reification style of parallel programming proposed by the Europa Consortium.
Engaging faculty in technology for teaching and research
Authors: Ricigliano Lori , Owen Shelley
Published: January 2007

As computer technology continues to develop at an unprecedented rate and costs for hardware decrease, its diffusion in higher education is growing dramatically. According to the National Center for Education Statistics, the number of students using computers in the first through fourth years of college increased from 39.2 percent in 1989 to 55.2 percent in October 1993.
1
Computers are everywhere on campus-in classrooms, labs, dorms, and offices. This widespread availability of technology in higher education has raised the hopes for radical changes and improvements in the teaching and learning process. While students have eagerly embraced technology, using computers as tools for communication, composition, and research, faculty, on the other hand, have used it much less in their work. Researchers speculate that one reason might be that faculty have experienced little or no computer training.
2
This phenomenon has created a unique challenge for those of us who train computer users. We must nurture and expand the skills of computer savvy students. At the same time, we must also educate faculty about the value of technology in meeting their teaching goals and objectives.
Individual differences and system development
Authors: Jiang James J. , Klein Gary Stephen , Pick Roger Alan
Published: January 2007

Using an order of magnitude more subjects, this replication of a study by Dos Santos and Hawk confirms its finding that system development professionals' attitudes can be classified as user-oriented, technically-oriented, or socio-politically-oriented. Furthermore, we found that these attitudes are related to such demographic individual differences as age, education, system development experience, and managerial position. We also looked for differences by gender, but the data do not support differences in attitude according to gender.
Timed Common Lisp
Authors: Anderson Scott D. , Cohen Paul R.
Published: January 2007

The two key features of Deliberation Scheduling and Anytime Algorithms are the duration of the computation and the resulting quality. Clearly, quality can be difficult to define and highly dependent on the domain. Duration, on the other hand, seems straightforward: how long the computation takes. But on what processor? Should the processor matter? What code counts in the computation? How is that code's duration modeled? These questions are addressed in this paper.
The Winter Simulation Conference
Authors: Wilson James R. , Brunner Daniel T. , Swain James J.
Published: January 2007

The Winter Simulation Conference (WSC) is the premier international forum for disseminating recent advances in the field of system simulation, with the principal focus being discrete-event simulation and combined discrete-continuous simulation. In addition to a technical program of unsurpassed scope and quality, WSC provides the central meeting place for simulation practitioners, researchers, and vendors drawn from all disciplines and from the industrial, governmental, and academic sectors.
Technophobia, papyrophilia, and the real thing
Authors: Greenberg Douglas
Published: January 2007

I am very flattered to have been invited to deliver the keynote address for this meeting. I understand, by the way, that I was the second choice after Phil Jackson; I am not sure what to make of that fact, except that if any of you expect me to get you a reservation at Michael Jordan's restaurant tonight, you will be disappointed.
ABSTRACTS: Sixth RIMS Conference on FORMULA MANIPULATION AND ITS APPLICATION TO MATHEMATICAL STUDY
Authors: Winkler Franz
Published: January 2007

The conference of the above title was held on November 13 to 15 in Kyoto. The conference chairman is Dr. Tateaki Sasaki, The Institute of Physical & Chemical Research, and the conference organizer is Prof. Hidetsune Kobayashi, Nihon University. Presented were fourteen papers on algorithm study, system implementation, and application to mathematics and physics. The number of attendants is about 60, from the fields of pure and applied mathematics, computer science, physics, and engineering. The papers presented and their abstracts are given below.
Symbolic and algebraic computation research in Italy
Authors: Gianni P , Miola A , Mora T
Published: January 2007

We like to fix the starting point of the research activities in Symbolic and Algebraic Computation (SAC) in Italy at the IFIP Working Conference on Symbol Manipulation Languages and Techniques held in Pisa in September 1966. This event in fact, stimulated early research conducted for several years by single researchers cooperating more with foreign colleagues than each other.
John Reid reports: X3J3 meeting, November 1986
Authors: Reid John
Published: January 2007

This was a very active meeting, with over 150 working documents, most of which were corrections and improvements to the draft standard, S8. The plan is to retypeset it immediately after the meeting (the chairman, vice-chairman, and editor are all staying behind to help) and send it out to members for a postal ballot over the period December 1st to January 5th. Only three members (IBM, DEC and Peritus) opposed holding such a vote. When asked how they anticipated voting in this ballot, two members (IBM and DEC) said 'no' and 5 abstained, so there seems every prospect for the required 2/3 majority. The February meeting will be devoted to considering the reasons for any 'no' votes and any comments that accompany 'yes' votes. Hopefully, we will forward the document to our parent committee, X3, in February. We will also forward it to IS0.
Performance and Evaluation of Lisp by R. Gabriel (MIT Press)
Authors: Price Keith
Published: January 2007

The first question a non-Lisp user will ask is: Why bother, aren't the standard Fortran benchmarks good enough? I know from experience that the speed of different versions of Lisp depends on more that the speed of the underlying machine, from having written a graph matching program in UCI Lisp for TOPS-20, then changing it to run in Franz on a 750 where the times increased by much more than the stated machine differences. This program was then moved to a Symbolics 3600 with an enourmous speedup (far more than the basic machine speed would indicate).
State of researches on the problem solver ARGOS-II
Authors: Fade Bernard , Picardat Jean-Francois
Published: January 2007

Several years ago, our team began researche on problem solvers. The first program which issues from this is ARGOS-I [CAY.76] [CAY.78] (Automatic Robot Generating its Own Strategy). It was a program written in PASCAL which tried to simulated the the evolution of an elementary robot in an "a priori" unknown world. ARGOS-I built plans of movements. It ran into two steps: the first objective deciding, and second path determining in order to reach the objective. Then it monitored its own movement (simulated).
Modeling and simulation of medium-access-protocols in local area networks
Authors: Katz Ilan
Published: January 2007

Local Area Networks are becoming the most common way of connecting a series of workstations to allow them to communicate with each other and share common resources. It is therefore becoming more and more important for network designers and installers to evaluate the ability of local area networks that use different communication protocols to handle the desired message loads. An issue in LAN performance is related to the properties of the medium access protocol, i.e., its throughput-delay characteristics. By medium access protocol we refer to the MAC (Medium Access Control) sublayer as defined by the IEEE-802 and the ISOOSI protocols. This paper focuses on two general classes of protocols: the first is known as Carrier Sense Multiple Access with Collision Detection (CSMA/CD) and the second is known as Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) or Bit-Mapped protocol. Two variations of each class are examined, and comparisons are made between the classes and the variants of each class.
Key factors in knowledge acquisition
Authors: Fellers Jack
Published: January 2007

In recent years there has been a tremendous increase in the development of Expert Systems (ESs) in organizations. This increased development is straining the already limited supply of qualified ES developers. These ES developers have come to be know as Knowledge Engineers (KEs), and their job as Knowledge Engineering. The process of Knowledge Engineering is divided into two tasks: Knowledge Acquisition (KA) and ES construction. KA has been defined as "The process of extracting, structuring, and organizing Knowledge from several sources, usually human experts, so it can be used in a program." (Waterman, 1986; p. 392) This process of KA has been identified as the "bottleneck" that currently constrains the development of ESs.This paper summarizes what is known about the KA process in an effort to identify what the key factors are that influence the success of the KA phase of the Knowledge Engineering process. Due to the similarities that exist between ESs and traditional systems development, the literature that pertains to traditional Information Requirements Determination and to Systems Analysts will be utilized to guide this exploration. Case study reports of actual ES development projects and the practitioner literature from this highly applied field will also be referenced. A model of the knowledge Engineering process has been developed and will be used to help determine and discuss the key factors that influence the KA process.Five key factors have been identified and will be discussed in detail. These factors are: the attributes of the participants in the ES development process; elicitation techniques utilized in the process; the development of external representations; representation selection problems; and the verification of the ES by the Domain Expert who participates in its continued development via the user-system interface. These factors are presented, key issues identified, and research questions suggested for each area.It is hoped that the analysis of the key factors in KA will lead to the identification of the skills and techniques necessary to successfully perform the KA process. Once these skills have been identified, training programs can be developed to help reduce the shortage of qualified KEs and, ultimately, facilitate the increased development of ESs in organizations.