bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic programming algorithms for the knapsack problem
Authors: Sniedovich Moshe
Published: January 2007

The knapsack problem is one of the "classical" problems in Operations Research. In this paper we present a number of APL codes based on the dynamic programming approach to such problems. Although these codes can be used effectively to solve small knapsack problems, they were developed primarily as teaching aids.
Object oriented librarianship
Authors: Bar-David Tsvi
Published: January 2007

We have been lectured at incessantly about the software crisis and the need to solve it. A solution - simple of statement but difficult of deployment - is
Re-use.
For, if I can re-use it (whatever
it
is), I don't have to design it, build it, or maintain it, with all the consequent benefits of reduction in cost and time to market.
Direct proof of a theorem by Kalkbrener, Sweedler, and Taylor
Authors: Kaltofen Erich
Published: January 2007

For given
f
1
,...,
f

m

∈
K
[
x
] that are relatively prime, where
K
is a field, Kalkbrener, Sweedler, and Taylor (1993) present degree bounds on the

a
i

needed to express 1 (and other low degree polynomials) as Σ
a
i
f

i

. Their bounds are an improvement on bounds given by Kakié (1976). This note presents a direct proof of the following fact.
Approximate mean value analysis of client-server systems with multi-class requests
Authors: Petriu Dorina C.
Published: January 2007

Stochastic Rendezvous Networks (SRVNs) are performance models for multitasking parallel software with intertask communication via
rendezvous
introduced in [1], which are very appropriate to model client-server systems. SRVNs differ from Queueing Networks (QNs) in two ways: nodes act as both clients and servers (allowing for nested service), and servers have two distinct phases of service—the first one “in RV” with the client, and the second “after RV”, executed in parallel with the client. Early work on solving SRVN models has used a kind of approximate Mean Value Analysis based on heuristic
ad hoc
assumptions to determine the task queue properties at the instant of RV request arrivals. Approximation are necessary since SRVN violates product form. Recently, a more rigorous approach was proposed in [2] for the solution of SRVN models, based on a special aggregation (named “Task-Directed Aggregation” TDA) of the Markov chain model describing the interference of different clients that contend for a single server with FIFO queueing discipline and different service times. The algorithm derived in [2] has the limitation that each client may require only a single class of service. In general, a software server offers a range of services with different workloads and functionalities, and a client may need more than one service. The present paper uses the TDA approach to derive an extended algorithm which allows a client to require any number of services from a server by changing randomly the request class. The new algorithm is incorporated into a decomposition method for models with any number of servers. The SRVN modelling technique is applied to a large case study of a distributed database system, giving insight into the behaviour of the system and helping to identify performance problems such as software bottle-neck.
Generative networkload models for a single server environment
Authors: Raghavan S. V. , Vasukiammaiyar D. , Haring Gunter
Published: January 2007

Any performance evaluation study requires a concise description of the workload under which the performance of the system is to be evaluated. Also, the repeatability of the experiments for different workload profiles, requires that the workload models generate the workload profiles parametrically. Such a model, should preferably be time-invariant, consistent and generative. We view the networkload as a sequence that can be generated from the rules of a Context Free Grammar (CFG). Our approach combines the established practice of viewing the
workload as “consisting of a hierarchy”
and
the CFG description
, to produce a generative networkload model. The networkload model is applied to a SingleServer-MultipleClients network by deriving the networkload model parameters from an operational SingleServer network of personal computers. The time-invariance and generative nature are verified experimentally. The usefulness of such a description of the networkload to study the resource management problems of a network, like the optimal allocation of clients to servers, is explored by using the generative model as input descriptor to a queueing network model of SingleServer network.
A microprogrammable architecture with quasi time-transparent structured control
Authors: Tudruj M. S. , Gajda R. F.
Published: January 2007

The paper is concerned with efficient implementation of evolved modular and structured microprogramming. A microprogrammable architecture is presented that permits designing hierarchical complicated modular microprograms at two distinct levels: the global control and the data processing level. The architecture is based on two cooperating microprogram control units that separately store and perform control and executive microinstructions and microcode modules. The control organization of an implementing computer is presented which assures the quasi time-transparency of modular control in microprograms during the microprogram execution. This is achieved by parallel functioning of constituent control units, that permits preparing in advance addresses of executive modules referenced by control microinstructions. The efficient implementation of control statements of high level languages and microprogramming at the assembler language level for the proposed architecture are also discussed in the paper.
Hardware acceleration of logic simulation using a data flow microarchitecture
Authors: Catlin G. , Paseman B.
Published: January 2007

Current digital logic simulators running on engineering workstations lack capacity and speed. This paper discusses a hardware accelerator for a workstation simulator which addresses these problems. The accelerator runs 100x faster than its software counterpart and can simulate up to 1 million gates. The accelerator has been built and is being sold commercially. The architecture of the accelerator is similar to that of a classical dataflow machine. We describe the architecture of the machine and illustrate how it would simulate a simple circuit. We then briefly discuss the relationship between event driven simulation and dataflow.
Some experiments in global microcode compaction
Authors: Su B. , Ding S.
Published: January 2007

Global microcode compaction is an open problem in firmware engineering. Although Fisher's trace scheduling method may produce significant reductions in the execution time of compacted microcode, it has some drawbacks. There have been four methods. Tree, SRDAG, ITSC , and GDDG, presented recently to mitigate those drawbacks in different ways.

The purpose of the research reported in this paper is to evaluate these new methods. In order to do this, we have tested the published algorithms on several unified microcode sequences of two real machines and compared them on the basis of the results of experiments using three criteria: time efficiency, space efficiency, and complexity.
Aberth's method for the parallel iterative finding of polynomial zeros
Authors: Chen Tien Chi , Luk Wai-Shing
Published: January 2007

Aberth's method for the iterative finding of polynomial zeros using simultaneous interacting guesses is seen to be the systematic use of Newton's method under Parallel Anticipatory Implicit Deflation (PAID), changing the single polynomial problem into that for a system of rational functions. It offers the prospect of parallel execution, discourages coincident convergences, and subjects all iterates to the same algorithm, without the uneven roundoff error accumulation due to deflation typical in serial iterative methods. Yet it converges slowly to multiple zeros, and consumes far more total computing power than serial methods. Factors hindering convergence include problem symmetry and clustering of iterates, alleviated by asymmetric initial guesses and an immediate updating strategy, as seen through the speedup in the experimental APL program PAIDAX.
An algebraic formula manipulation system for education and its implementation on different PCs
Authors: Kikkawa Makoto , Sugawara Koichi , Washio Yukio
Published: January 2007

When studying the application of APL to high school education to help students in their understanding of mathematical concepts, many teachers encountered difficulties in that the result of their study could not be used in their classes because schools had provided them with computer models which can not run APL. The authors and their co-workers of the Computer Study Group of MiYagi Prefecture Society of Mathematical Education found a way to solve such a difficulty by porting study files from NiHonGo APL to I-APL. This paper discusses the problems encountered in classrooms, the new system applied to three popular models of personal computers, the actual use of the APL study files in eight schools for learning polynomial factorisation, and evaluation of both teachers and students.
Time series forecasting using neural networks
Authors: Kolarik Thomas , Rudorfer Gottfried
Published: January 2007

Artificial neural networks are suitable for many tasks in pattern recognition and machine learning. In this paper we present an APL system for forecasting univariate time series with artificial neural networks. Unlike conventional techniques for time series analysis, an artificial neural network needs little information about the time series data and can be applied to a broad range of problems. However, the problem of network “tuning” remains: parameters of the backpropagation algorithm as well as the network topology need to be adjusted for optimal performances. For our application, we conducted experiments to find the right parameters for a forecasting network. The artificial neural networks that were found delivered a better forecasting performance than results obtained by the well known ARIMA technique.
An implementation of prediction calculation using APL and Clipper
Authors: Luneva Inna N. , Obraztsov Sergei M. , Shimkevich Alexander L.
Published: January 2007

This paper describes the algorithm for the prediction calculation based upon the non-linear algebraic models' self-organization. Special block for a function recognition provides the decrease of the predicted equations exhaustive search at every stage of model building. Another peculiarity is the bootstrap use as supplementary external criterion. The implementation of this algorithm is a complex software system (calculating module is built in APL*PLUS and user-friendly interface is built in Clipper 5.01). This system works as DOS-application for Windows with dynamic data exchange. We present results of testing the system on real currency exchange rate.
The impact of APL on first year mathematics
Authors: Spunde Walter G.
Published: January 2007

In 1993, the Australian Federal Government's Committee for the Advancement of University Teaching (CAUT) funded a project to develop an integrated
computationally rich
first year mathematics course built on the use of APL as an integral part of the instruction. This article outlines how the standard syllabus was amended to respond to the available computing power for elucidating mathematical topics and what mathematical skills were improved or neglected by the novel presentation.
SCHEMASIM
Authors: Coomber Christopher J.
Published: January 2007

The design of real-time systems is inherently difficult because of the strict functional and temporal constraints such systems must satisfy when in operation. Often computer simulation plays a vital role in modelling real-time systems and is useful for determining whether sub-systems interact properly, timing constraints are upheld, and predictable behavior prevails in abnormal situations.In this paper, a new environment, called SCHEMASIM, for simulating real-time systems is overviewed. SCHEMASIM allows the designer to construct a graphical model of the intended real-time system and its environment and to describe essential functional and time-dependent behavior. An underlying discrete event simulator controls the graphical animation of the model and allows full user interaction.
Putting Together the Technical Program
Authors: Ehrlich Kate
Published: January 2007

Why do people go to a local SIG meeting? To meet their friends, hear the local gossip, pick up a few tips or have a night out? It could be any number of things. Ultimately, what draws people to a local SIG meeting is the quality of the speakers and topics. In this issue, we look at some of the work that goes on behind the scenes to create a technical program that is stimulating and retains local color and interest.
AVI '94: An International Workshop
Authors: Shneiderman Ben , Badre AI , Santos Paulo
Published: January 2007

The fresh Mediterranean breezes of innovation enlivened the workshop conversations at Advanced Visual Interfaces '94 (Bari, Italy June 1--4, 1994). More than 100 participants met on the flower-gardened grounds of the Grande Albergo di Villa Romanazzi Carducci, whose modern hotel plus conference center complemented the beautifully restored old villa and the marble-lined swimming pool. Being together with active professionals from Europe and America for 4 days gave us an in-depth chance to learn about each other's professional and personal outlooks. The ancient Roman architecture and the traditional Italian surroundings reminded us that the impact of our work could also last for two thousand years and shape many people's daily lives.
Book review: Human-Computer Interaction, by Jenny Preece, Yvonne Rogers, Helen Sharp, David Benyon, Simon Holland, and Tom Carey (Addison-Wesley, 1994)
Authors: Perlman Gary
Published: January 2007

One of the most significant events at CHI '94 in Boston did not appear in the program, and although it was conspicuous to some, it probably went unnoticed by most of the attendees. Given the venue, perhaps its name made it blend into the background. At the Addison-Wesley booth in the commercial exhibits room, a textbook made its debut:
Human-Computer Interaction
, by Jenny Preece and five others: Yvonne Rogers, Helen Sharp, David Benyon, Simon Holland, and Tom Carey.
A new approach to conformance
Authors: Billingsley Pat
Published: January 2007

For the past several years, members of the ISO TC159-SC4/WG5 standards committee have been struggling to devise an appropriate conformance model for the software-related parts of the ISO 9241 standard,
Ergonomic requirements for office work with visual display terminals.
Part 14 of ISO 9241,
Menu dialogues
, has been the testing ground for the conformance issue. Several different approaches to conformance have been proposed by the committee, and each has subsequently been rejected by the ISO member nations who vote on drafts of Part 14.
Design, specification, verification of interactive systems
Authors: Paterno Fabio
Published: January 2007

The workshop was held in the Monastery of the Holy Cross, run by monks of the Carmelite Order. It was attended by 32 delegates from 11 European and American countries. Most participants came from universities or public research institutes and some from industry. Twenty papers were selected for the final program from 32 submissions. Ten of them were presented, the other ten were considered in the discussion sessions of the workshop as its aim was to promote discussion rather than paper presentation.
The practical management of computer ethics problems
Authors: Smith John W.
Published: January 2007

Ethics can be the most concrete, and the most abstract, of subjects. We have all experienced the intense feeling that comes when one is the target of an ethical infringement. It is very real and substantive. If you tried to go beyond your feelings, and particularly if you tried to reconcile your feelings with those of others, you might have found the experience like moving water with a broom. Lots of commotion, but little reduction in the level of the problem.
A unified framework for conservative and optimistic distributed simulation
Authors: Jha Vikas , Bagrodia Rajive L.
Published: January 2007

A great deal of research in the area of distributed discrete event simulation has focussed on evaluating the performance of variants of conservative and optimistic methods on different types of applications. Application characteristics like lookahead, communication patterns, etc. have been found to affect the suitability of a specific protocol to simulate a given model. For many systems, it may be the case that different subsystems possess contradictory characteristics such that whereas some subsystems may be simulated efficiently using a conservative protocol, others may be more amenable to optimistic methods. Furthermore, the suitability of a protocol for a given subsystem may change dynamically. We propose a parallel simulation protocol that allows different parts of a system to be simulated using different protocols, allowing these protocols to be switched dynamically. A proof of correctness is presented, along with some preliminary performance discussion.
Investigations in adaptive distributed simulation
Authors: Hamnes Donald O. , Tripathi Anand
Published: January 2007

A new adaptive protocol for distributed discrete event simulation is proposed. This protocol spans the continuum of protocols from conservative to optimistic allowing each process in a distributed simulation to adapt to the specific simulation problem at runtime. An actual implementation of the protocol has been tested on a network of workstations for a closed queueing system. The results are very favorable and the algorithm has outperformed a conservative and an optimistic protocol in some cases.
Stability of event synchronisation in distributed discrete event simulation
Authors: Kumar Anurag , Shorey Rajeev
Published: January 2007

This paper is concerned with the behaviour of message queues in distributed discrete event simula
tors
. We view a logical process in a distributed simulation as comprising a message sequencer with associated message queues, followed by an event processor. We show that, with standard stochastic assumptions for message arrival and time-stamp processes, the message queues are
unstable
for conservative sequencing, and for conservative sequencing with
maximum lookahead
and hence for optimistic resequencing, and for any resequencing algorithm that does not employ interprocessor “flow control”. These results point towards certain fundamental limits on the performance of distributed simulation of open queueing networks.
Cost of state saving & rollback
Authors: Cleary John , Gomes Fabian , Unger Brian , Xiao Zhonge , Thudt Raimar
Published: January 2007

Approaches to state saving and rollback for a shared memory, optimistically synchronized, simulation executive are presented. An analysis of copy state saving and incremental state saving is made and these two schemes are compared. Two benchmark programs are then described, one a simple, all overhead, model and one a performance model of a regional Canadian public telephone network. The latter is a large SS7 common channel signalling model that represents a very challenging, practical, test application for parallel simulation. Experimental results are presented which show the necessity and sufficiency of incremental state saving for this application.
Adaptive checkpointing in Time Warp
Authors: Rönngren Robert , Ayani Rassul
Published: January 2007

In Time Warp optimistic discrete event simulation, there exists a need to occasionally save the states of the logical processes. The state saving often constitutes a substantial overhead. However it is not necessary to save each state of a logical process since states can be restored from earlier states by re-executing intermediate events. In this paper, we analyse the effects of doing the state saving less frequently and present a method that allows each logical process to adapt its state saving interval to its rollback behaviour. Experimental results indicate that the proposed method improves performance of the Time Warp system.
A static partitioning and mapping algorithm for conservative parallel simulations
Authors: Boukerche Azzedine , Tropper Carl
Published: January 2007

In this paper, we consider the problem of partitioning a conservative parallel simulation for execution on a multi-computer. The synchronization protocol makes use of null messages [6]. We propose the use of a simulated annealing algorithm with an adaptive search schedule to find good (sub-optimal) partitions. The paper discusses the algorithm, its implementation and reports on the performance results of simulations of a partitioned FCFS queueing network model executed on iPSC/860 hypercube. The results obtained are compared with a random partitioning. They show that a partitioning which makes use of our simulated annealing algorithm results in a reduction of 25-35% of the running time of the simulations when compared to the running time of a random partition of the model.
A case study in signal processing microprogramming using the URPR software pipelining technique
Authors: Mueller R. A. , Su B. , Duda M. R. , Plomondon B. L.
Published: January 2007

There are a growing number of micro-architectures that employ pipelined array units for high-speed floating point applications. To obtain the performance required in such applications, effective loop optimization is crucial. The loop optimization problem for micro-architectures with pipelined processing units is similar to the problem of array processor loop optimization. The URPR method has been proven to be an effective, low-complexity approach to optimizing loops in array processor programs, so we conducted a case study of the method applied to a representative pipelined microarchitecture based on the AMD29500 chip family. The results of applying two URPR compaction algorithms and a new compaction algorithm to the 29500-based micro-architecture are presented. With the new compaction algorithm, we were able to realize microcode as efficient as the complex microcode manually derived by AMD.
A microcoded RISC
Authors: DuBose D. K. , Fotakis D. K. , Tabak D.
Published: January 2007

A new, microcoded, RISC-type system is proposed and presented. The microcode is stored in a 256 x 64 PROM Nanomemory in the CPU. The 8-bit opcode of each instruction is a direct address to the Nanomemory. Each Nanomemory 64-bit word (horizontal microcode) corresponds to a specific machine language instruction. A large 2048 x 32 CPU Register file, using the register window approach, is implemented. A bit-sliced (AMD2900) prototype is currently under construction.
TESSA—an image testbed for evaluating 2-D spatial similarity algorithms
Authors: Gudivada Venkat N.
Published: January 2007

In multimedia database applications, a major class of users' requests require retrieving those images in the database that are spatially similar to the query image. To process such queries, a spatial similarity algorithm is required. A spatial similarity algorithm assesses the degree to which the spatial relationships among the domain objects in a database image conform to those specified in the query image. The recent ubiquitous interest in multimedia information systems has spurred a great interest in spatial similarity algorithms. A standard testbed of images is required not only to systematically evaluate these algorithms but also to compare and contrast them. However, there is no such testbed of images available for this purpose.In this paper, we describe a collection of images, referred to as TESSA, as a testbed for investigating the robustness of spatial similarity algorithms and their further use in evaluating the retrieval effectiveness of these algorithms. The TESSA collection comprises 160 images and are produced by generating 15 variants of each of the 10 original images. Image variants are produced by scale, rotation, and translation, and by an arbitrary composition of these three transformations. The variants are designed to inquire into the robustness of spatial similarity algorithms. To facilitate their further use in evaluating the retrieval effectiveness, each image in TESSA is considered as a query in turn, and an expert is asked to provide a rank ordering of the TESSA images with respect to the query image vis-a-vis expert provided rank ordering. System provided rank ordering for a query image is the rank ordering of TESSA images induced by a spatial similarity algorithm with respect to the query. Retrieval effectiveness of spatial similarity algorithms is then characterized by using R
norm
measure. This measure is based on both the expert and system provided rank orderings.
The Work of IFIP Working Group 2.7
Authors: Gram Christian
Published: January 2007

As a follow-up on John Karat's paper in a previous SIGCHI bulletin on IFIP's activities [Karat93], the present article describes another IFIP-activity of interest to the HCI community.
ANSI/HFES software user interface standardization: critical issues
Authors: Reed Paul
Published: January 2007

This paper reviews recent developments in the area of software user interface standardization, and identifies issues that must be addressed before an effort to establish an American National Standards Institute (ANSI) software user interface standard can be successfully completed. Arguments supporting and opposing the establishment of software user interface standards are reviewed. Potential resolutions to the critical issues including technical, organizational, logistical, and political issues are identified and discussed.
Defining the requirements for HCI design methods
Authors: Sutcliffe Alistair
Published: January 2007

The workshop was attended by 20 delegates from European, USA and Japan. Industry was particularly well represented. Thirteen position papers were presented on three themes.
Human factors in IS
Authors: Te'eni Dov , Kirk Katrine , Schultze Ulrike , Day Donald
Published: January 2007

The series of symposia on Human Factors in Information Systems (HFIS) emphasizes research on human issues related to information systems in their organizational context, such as studies of relationships between users, IS professionals and computerized systems. The HFIS symposia were initiated by Jane Carey (Arizona State University) in 1986, and are still held as workshops in which some 40 participants from academia and industry interact intensively for 2--3 days. This year the symposium was organized by Dov Te'eni at the Weatherhead School of Management of Case Western Reserve University (Cleveland, Ohio) and had Group Support Systems (GSS), also known as computer supported cooperative work (CSCW), as a central theme.
Technological trends applications and markets
Authors: Thuering Manfred , Haake Anja , Haake Joerg M.
Published: January 2007

This year's ACM conference on hypertext (HT'93) took place in Seattle, Washington, USA from November 14 to November 18. It followed the European ACM Conference on Hypertext (ECHT) which was held in Milan, Italy, 1992. Almost 650 people attended HT'93: about 54% from industries, 44% from research organizations and 2% from others. The overwhelming majority were from the US and Canada (82%), followed by European participants (12%) mostly from the United Kingdom, Germany, Denmark, Italy, France, The Netherlands, Portugal, and Austria and participants from other countries (6%) mostly from Japan, Korea, and the Argentine.
From informal requirements to agent-based specification
Authors: Fields B. , Harrison M. , Wright P.
Published: January 2007

Previous work has demonstrated how interactive systems can be modelled formally as a collection of interacting objects or
agents
using an
agent-based
specification language (Abowd 1991, Duke & Harrison, 1992). An agent is an object which encapsulates some private internal state and operations which may alter this state together with an external view which describes the behaviour of the system in terms of the user interface level events which occur and the
rendering
function by which the object makes aspects of its internal state visible to the environment.
Book review: A Prelude to Neural Networks: Adaptive and Learning Systems. Edited by Jerry M. Mendel (PTR Prentice Hall 1994)
Authors: Gori M.
Published: January 2007

The book was originally published twenty-four years ago with a different title "Adaptive Learning and Pattern Recognition Systems" (J. M. Mendel and K-S. Fu' Eds). Now, it has been reedited by Mendel and dedicated to the memory of King-Sun Fu. The book is supposed to provide a bridge between today's "second wave" of neural networks and the "first wave" that occurred in the sixties. It is organized in three parts: pattern recognition, adaptive and learning systems, and special topics. Such organization is well conceived, though, in my opinion, the final part is today so relevant that it would perhaps have deserved a more specific title.
Book review: Readings in Philosophy and Cognitive Science by Alvin I. Goldman (MIT Press/Bradford Books 1993)
Authors: McNally Myles F.
Published: January 2007

Alvin Goldman is a well known philosopher who feels that cognitive science can make positive contributions to philosophy.
Readings in Philosophy and Cognitive Science/
is a large, very nicely done volume of important articles by philosophers and cognitive scientists. Conceived by Goldman as a companion to his recent text
Philosophical Applications of Cognitive Science/
[ag:paocs], it connects work in the various disciplines of cognitive science to philosophy. The two texts make a strong case that philosophy must take seriously work in the cognitive sciences. The emphasis is primarily on the constituent discipline of psychology, particularly cognitive psychology. AI researchers will find their discipline rather underrepresented in both volumes. The books are best seen as offering AI researchers a good look at how the other constituent disciplines of cognitive science impact the naturalization of philosophy.
A consideration of some approaches to course organization
Authors: Thomas S. Rebecca
Published: January 2007

An introductory artificial intelligence course may be taught with emphasis on theory and formalism ("science"), or with emphasis on designing and building artifacts that display intelligence ("engineering"). Along another dimension, it makes pedagogical sense to organize the course around a central theme, but the course may instead be taught as a smorgasbord of approaches and problems. This paper briefly considers the four possible combinations of approaches.
Interactive learning tool for statistical reasoning with uncertainty
Authors: Vastola Deborah A. , Walker Ellen L.
Published: January 2007

We describe a tool which was developed as a Masters project to help students learn the concepts of reasoning with uncertainty. While the initial implementation has focused on Dempster-Shafer theory, the tool is designed so that it can be expanded to other models of uncertain reasoning. The tool uses interactive graphical representations, together with animation and color, to convey the principles of reasoning with uncertainty. It runs on the Unix platform under the X-window system and uses the SUIT toolkit [1].
Book review: Learning in Embedded Systems by Leslie Pack Kaelbling (MIT Press, 1993)
Authors: Boasson Maarten
Published: January 2007

Despite adorning the cover with one of Albrecht Dürer's perspective studies, the figures in this book are drawn without perspective. Fortunately the pedestrian figures are the weakest aspect of this massive study of geometry-laced vision. Every aspect of this book is generous: its length (663 pages), its margins (5.5cm), the number of bibliographic entries (\sim 300), the 16 pages of figure captions, the long algebraic derivations (four pages to derive the Kalman equations [pp. 308--312]; another four for a kinematic screw equation [pp. 375--379]), the coverage, and the explanatory style.
Relating the performance of partial-order planning algorithms to domain features
Authors: Knoblock Craig A. , Yang Qiang
Published: January 2007

The AI planning field has a long history of introducing yet another search algorithm that is believed to be the best in all domains. Some recent examples are NONLIN, TWEAK and SNLP. In this paper we show, by directly comparing the above three planners, that the quest for an overall winner is doomed to fail. We first argue that these three planners differ in a variety of ways, including methods for termination check, causal-link protection, and subgoal selection. These differences entail different search behaviors in terms of factors such as the branching factor, the search depth and the time spent by the algorithm on each search node. Furthermore, the search behavior is closely related to the characteristics of the problem domain in which a planner is operating. In this paper we identify one such domain feature, expressed as the ratio of the number of negative threats to the number of positive threats. We present an artificial domain where we can control this ratio and show that in fact the planners show radically different performance as the ratio is varied in this domain. The implication of this result for someone implementing a planning system is that the most appropriate algorithm will depend on the types of problems to be solved by the planner.
Simulation driven resource allocation in ATM networks
Authors: Alqaed Abdullah M. , Chang C. Hwa
Published: January 2007

Asynchronous Transfer Mode (ATM) traffic is characterized by a wide variety of traffic source classes. Each class of traffic has differing effects on the buffer and link capacity resources of the network. This results in a high level of complexity in predicting resource allocations for each source. The network must be managed in real-time in order to avoid congestion which tends to collapse its utilization. Network congestion requires admission control which in turn must require a measure of resource requirements from a randomly variable source. In this paper we proposed a frequency-domain probability density function convolution method for predicting the resource requirements of a source based on its input characteristics. A taxonomy and classification of sources based on measurable characteristics is also proposed. The classes of sources are simulated and the resulting requirements are compared to the prediction. A feedback mechanism is described which can result in a highly accurate and very efficient table lookup method for realtime resource allocation in ATM multiplexing switches.
Quantum modeling of distributed object computing
Authors: Butler James M.
Published: January 2007

Distributed object computing is rapidly gaining notice in the computer engineering community. In response, productized support for these systems is increasing. However, few tools exist for the design and modeling of distributed object systems. Clearly, large scale and mission critical systems are most affected by this deficiency. To attain a level of tractability in large scale design and verification, dynamic models are essential. This paper introduces two modeling components. First, the LCN (Loosely Coupled Network) model supports the definition of real-world network topologies and multicomputer systems. Second, the DCO (Distributed Cooperative Objects) model provides a system-independent method of representing complex, object oriented computing structures. These components are assigned random variables (e.g., bandwidths, error rates, compute loads, data volumes, etc.) that provide a basis for dynamic behavior. Through surjective mapping of DCO software onto LCN hardware, the complete OSM (Object System Mapping) model is created. It is shown that OSM systems can model all modes of distributed object behavior found in the current state of
Object Request Broker
(ORB) technology while under the constraints of modern network structures. The paper concludes with a qualitative analysis of these behaviors and sets the foundation for a distributed object simulation facility.
An information systems perspective of the SIGCHI curricula
Authors: Strickland Ted J.
Published: January 2007

The SIGCHI curricula report published in 1992 [ACM 1992] describes four proposed courses in HCI and two model curricula for HCI. This paper critiques the curricula report's recommendations as they pertain to an undergraduate information systems course and to the structure of a recently revised curriculum in Computer Information Systems. The evaluation found that the curricula report is useful as an initial set of curriculum guidelines, but that customization of its recommendations is needed to satisfy individual program, college, and university objectives. Suggestions for improvements to the curricula report and advice to information systems curriculum developers are listed.
Programmable applications
Authors: Eisenberg Michael
Published: January 2007

Current fashion in "user-friendly" software design tends to place an over-reliance on direct manipulation interfaces. To be truly expressive (and thus truly user-friendly), applications need both learnable interfaces and domain-enriched languages that are accessible to the user. This paper discusses some of the design issues that arise in the creation of such
programmable applications.
As an example, we present "SchemePaint," a graphics application that combines a MacPaint-like interface with an interpreter for (a "graphics-enriched") Scheme.
Pointing in entertainment-oriented environments
Authors: Westerink J. H. D. M. , van den Reek K.
Published: January 2007

Multimedia applications for consumer entertainment often employ a point-and-select interaction style, borrowed from more task-oriented computer applications. The environment of use and the pointing devices involved are so different, however, that a higher importance should be attributed to the users' appreciation of the pointing device than to its efficiency or any other objective performance measure. We set up an experiment to investigate how appreciation and performance measures relate. The experiment involved six different input devices, two CD-i titles and 16 subjects making both voluntary and prescribed cursor control movements. For the mouse-like pointing devices we obtained a Fitts' Law-like dependence on target width and target distance. This was, however, not replicated for any of the other input devices, mainly owing to a positive influence of cursor constraints. Concerning the relation of the performance measures with the users' appreciation, we found that neither time-to-target nor relative-path-length on its own is a reliable indicator of the users' appreciation. Together, however, they might explain the appreciation scores to a considerable extent.
An overview of portable GUI software
Authors: Guthrie Wade
Published: January 2007

This article attempts to bring together as much information as possible concerning platform-independent Graphical User Interface (PIGUI) development kits. It is based on a FAQ list (answers to Frequently Answered Questions) maintained and periodically updated as a service to the net by the author.What is presented here is a number of tables summarizing available PlGUI's, followed by descriptions of the individual products, with reviews and users' comments where possible.
The anomaly of other-directedness
Authors: Harrington Susan J.
Published: January 2007

Despite the existence of laws and much publicity surrounding illegal software copying, it is widely believed that software copying is commonplace. Yet reasons why such illegal behavior continues to occur are lacking. This study used a model of ethical decision making as a guide for research and found the individual factor of other-directedness helped explain IS personnel's intentions toward illegal software copying. No such individual factor was related to judgments concerning right and wrong. These findings suggest that highly other-directed IS personnel may behave against their better judgment, especially in cases where they perceive unethical behavior is commonplace. Implications for management and ethics education are discussed.
Recycling APL code into client/server applications
Authors: Busman Richard J. , Fil Walter G. , Kondrashev Andrei V.
Published: January 2007

This paper analyzes the current state of modern APL and deals with the authors' experiences in recycling and downsizing old APL applications and transforming them into more open information systems using client/server technology on different hardware and software platforms.
Rank and uniformity
Authors: Hui Roger K. W.
Published: January 2007

Rank is elucidated through an executable model. Integrated rank support for specific functions can be vastly more efficient than the general algorithm in computing
v"r
, and uniform verbs provide a way to extend the more efficient implementation to a large class of verbs.
Regression analysis with fuzzy knowledge representation
Authors: Louneva Inna N. , Obraztsov Sergei M. , Shimkevich Alexander L.
Published: January 2007

An algorithm for fuzzy non-linear estimation and an APL implementation of this algorithm are discussed. The algorithm is based on using probability distributions for experimental data. The parameters of the distributions are given as linguistic variables by an expert.
Infix, cut and finite automata
Authors: Reiter Clifford A.
Published: January 2007

The behavior of one and two dimensional automata are displayed in two and three dimensions and via animations. Implementations of finite automata in J using “infix” and “cut” to distribute local definitions of finite automata are compared. Abstract automata are considered along with applications to image processing and surface plotting.
Book review: Computational Organization Theory. Edited by Kathleen M. Carley and Michael J. Prietula (Lawrence Earlbaum, Publishers, 1994)
Authors: Tuggle Francis D.
Published: January 2007

This book arose from a 1992 workshop sponsored by the College on Organizations of The Institute of Management Sciences (TIMS). The book reports on 13 different approaches to computer-based studies of organizational phenomena, largely organizational design issues, where the creative spark fired from artificial intelligence and/or expert systems methodologies. While the resulting models are more complex than mathematical models, they are sometimes as complex as the organizations they are meant to study. However, computer-based models of organizations are one of the most powerful tools we have in the arena of normative organizational theory. Richard M. Cyert, one of the founders of TIMS, and one of the early advocates of bringing computer modeling to the study of organizations, provides a forward to this volume that does look forward---to that happy day when suitably complex models will be confronted with actual behaviors from live organizations.
Visualization of the microcirculation by laser Doppler perfusion imaging
Authors: Wȧrdell Karin , Anderson Chris , Andersson Thomas
Published: January 2007

Over the last decade a number of emerging technologies have become available for the study of microvascular blood flow. Some of these methods traumatize the tissue and seriously disturb the microcirculation; others have practical limitations in clinical use. Methods for clinical studies of the blood flow in small vessels should therefore preferably be non-invasive, versatile and easy to use. Most of the available methods that fulfill these conditions are based on optical measurement technology e.g. videomicroscopy [Fagrell et al., 1977], photopletysmography [Challoner 1979] and laser Doppler flowmetry [Nilsson et al., 1980 a,b]. Among these methods, the fiber based laser Doppler technique is the most common. This technique makes possible continuous recording of tissue blood flow at one or several sites. Because of the large spatial variation in tissue blood flow [Braverman et al., 1990] it would, however, be preferable to record the perfusion from a larger area allowing visualization of the spatial variations in tissue blood flow. This paper describes a non-invasive and nocontact system for mapping tissue perfusion, laser Doppler perfusion imaging (LDI). In addition, some potential clinical applications are illustrated.
The class storage and retrieval system
Authors: Nelson Michael L. , Poulis Tilemahos
Published: January 2007

Object-oriented programming (OOP) allows code developed for one class (the superclass) to be reused (via inheritance) in building another class (the subclass). Typical OOP systems provide a browser of some sort to allow the developer to peruse through libraries of classes, searching for an appropriate superclass to inherit from. However, as the number of classes involved grows from the tens to the hundreds to the thousands, the developer needs a very high level of knowledge about existing classes to minimize the search time. We have developed the Class Storage and Retrieval System (CSRS) which utilizes an underlying database management system to store and retrieve class definitions. Queries are then posed to the system to determine if any potential superclasses exist. The developer may then browse through a much smaller set of classes to determine if any are appropriate for the new application.
PPIG-7
Authors: Sonnenwald Diane H.
Published: January 2007

The Psychology of Programming Interest Group (PPIG) is a multi-disciplinary network of researchers and practitioners interested in understanding cognitive, social, and educational aspects of programming and design. The group meets yearly to discuss their research progress and issues in an informal, supportive environment. This year's workshop, PPIG-7, was held at the University of Edinburgh, 4-6 January 1995.The organizers of PPIG-7 were Helen Pain (local organizer), Thomas Green, and Ben du Boulay; students at the University of Edinburgh assisted during the workshop. PPIG-7 was sponsored by the Engineering and Physical Science Research Council.Work from a variety of countries and disciplines was discussed at the workshop. Presentations were divided into the following themes: Tools and Techniques, Design Strategies, Competence, Knowledge and Learning, Using Diagrams and Graphical Programming Languages, and Perspectives. Following is an overview of the talks presented in each theme. Affiliations and email addresses of authors are provided so readers can contact the authors directly for further information.
Mapping the discourse of HCI researchers with citation analysis
Authors: Dillon Thomas W.
Published: January 2007

This paper observes the development of human-computer interaction as a research discipline from 1991 to 1993. From a citation analysis of three volumes of three journals, the field of human computer interaction is identified as emerging from a supporting base of four fields: computer science, information systems, psychology, and human factors/ ergonomics. Results of this analysis support the proposition that human-computer interaction is emerging as a distinct field of study.