bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing of cross-sectional image data for reconstruction of human developmental anatomy from museum specimens
Authors: Doyle Michael D. , Ang Cheong , Raju Rakesh , Klein Gary , Williams Betsey S. , DeFanti Thomas , Goshtasby Ardeshir , Grzesczuk Robert , Noe Adrianne
Published: January 2007

A project is described (The Visible Embryo Project) to develop software strategies for the creation of large-scale databases of 3-dimensional image data on human developmental anatomy. The issues discussed relate to the processing of serial-section image data for the purpose of reconstructing volumetric models of individual embryos from museum specimens. Attempts were made to fully automate the processes of image registration and artifact correction, in order to allow for the eventual unattended reconstruction of thousands of such embryos from such resources as the Carnegie Collection of Human Embryology. Tools were also developed to allow the real-time interactive visualization of the massive databases that this type of reconstruction project creates. The implementation of a 3-D model of a human embryo in a viewer-centric virtual reality environment is also described.
Microprogram control of a Prolog machine
Authors: Koyama Kiyomi
Published: January 2007

A Prolog machine design and its control are described. The machine features two-stage pipelining, a triple bus interconnection data path and support for concurrent control of micro-operations. The objective of this design is to improve execution of a Prolog processor by simultaneously performing multiple micro-operations. Capabilities of concurrent operation support are described in detail and demonstrated using some example Prolog functions. Two-stage pipeline technique as applied to non-deterministic control of Prolog program execution will be presented.
HILEVEL microcode development system
Authors: Edwards Ken
Published: January 2007

HILEVEL's DS3700 Series Emulyzers provides full microcode development support. The DS3700 combined with HALE (an advanced retargetable Macro-Meta Assembler), with software for firmware integration and debug, and with a host computer provides a complete microcode development system.
A suite of microarchitectures for evaluating microcode compilers for other than for ISA interpretation
Authors: Linn Joseph L.
Published: January 2007

This note describes a suite of microarchitectures that has been developed for evaluating microcode compilers. These architectures are not especially appropriate for the interpretation of "normal" instruction set architectures owing primarily to the lack of efficient facilities for buffering and decoding ISA level instructions. Also, a single-level, nonpartitioned control store organization is used that may not be the optimal choice for the architectures in this family.
Contributed Articles: Operators Considered Harmful
Authors: Gfeller Martin
Published: January 2007

The distinction between operators and functions is shown to be arbitrary and complicated. An unification of those two object classes is proposed. Consequences for syntax and representation of functions are considered. Arrays of functions are shown to be a natural consequence of the unification.The paper is based on the terminology used in "Rationalized APL" [Iverson 83a]. Knowledge of this work is assumed.

F,G,H

denote functions,

A,

α,ω
arrays. Index origin is 1 in the refined language and throughout this paper.
The condition specification
Authors: Page Ernest H.
Published: January 2007

The past decade of research in simulation modeling methodology has seen a growing appreciation and understanding of the importance of both the process and product of model representation (commonly referred to as model specification). This article presents a brief discussion of the evolving role of one simulation model specification language, the condition specification, within an environment approach to simulation model development and support.
Efficient programming in Maple
Authors: Salvy Bruno
Published: January 2007

Studying the computation of orbits of some given group acting on a set, we show how successive refinements of a simple program provide a speedup factor of up to 200. The initial program cannot solve the problem at all, it is first converted into a program which needs one c.p.u. week and after all the optimizations have been performed, the computation takes only four hours. Although the problem is specific, we shall show that many of the optimizations we use are of interest for other problems as well.
Symbolic incidence geometry proposal for doing geometry with a computer (Part 1 of 2)
Authors: Beutelspacher Albrecht , Ueberberg Johannes
Published: January 2007

In the past, the computer has been used in geometry largely in order to solve particular problems of construction or non-existence.
Book review: ACTIVE VISION. Edited by Andrew Blake and Alan Yuille (MIT Press, Cambridge, MA, 1992)
Authors: Rosenfeld Azriel
Published: January 2007

The term "active vision", which began to be used to a significant degree in the second half of the 1980's, has several possible interpretations. Generally speaking, it can be thought of as a reaction against the "passivist" school which regards vision as "the process of discovering from images what is present in the world" (as Marr defined it in his classic book). This reaction can take several forms.
VISION by Pierre Buser and Michel Imbert (MIT Press, Cambridge, MA, 1992)
Authors: Rosenfeld Azriel
Published: January 2007

This is a textbook on biological vision, translated from the 1987 French edition (Hermann, Paris) by R. H.~Kay, Emeritus Fellow of Keble College, Oxford, UK. The authors are Professors of Comparative Neurophysiology and Visual Neuroscience (respectively) at the Universite Pierre et Marie Curie in Paris.
Book review: UNDERSTANDING MUSIC WITH AI: Perspectives on Music Cognition Mira Balaban, Kemal Ebcioglu, and Otto Laske, editors (AAAI Press/MIT Press; Cambridge, MA; 1992)
Authors: Christensen Carl M.
Published: January 2007

Music has been influenced by technical advances throughout history. From catgut to copper wire, tubes to transistors, records to CD's, the marriage of music and technology has remained fairly stable, even though some purists would like a divorce. As the relatively new field of computer science has grown, computer music applications and systems have increased as well. Now music is being used both to illumine the fields of artificial intelligence and cognitive science as well as reap the benefits that research in these fields can offer. A collection of such works can be found in 'Understanding Music With AI'.
Book review: The Design and Analysis of Efficient Learning Algorithms by Robert E. Schapire (MIT Press, 1992)
Authors: de la Maza Michael
Published: January 2007

This monograph is a slightly modified version of Schapire's 1991 MIT PhD thesis which won the 1991 ACM Doctoral Dissertation Award. The thesis, completed under the direction of Ronald L. Rivest, makes several major contributions to the field of computational learning theory.
Database model for design data
Authors: Savnik Iztok , Mohorič Tomaž , Dolenc Tomi , Novak Franc
Published: January 2007

The paper presents a
Construction Database Model
used for conceptual level modelling and manipulation of design objects. A primary intention of the CDM model is modelling hierarchically structured objects and generic dependencies between objects in design or in engineering applications. The CDM is an attribute based data model, therefore, all object properties are described by attributes. The leading idea of the CDM model is the representation of various abstractions identified in the semantic database models GSM, IFO, SAM* and FDM with attributes. To distinguish between different abstractions, the notion of
attribute role
is introduced. Attribute role divides attributes into different categories on the basis of the attribute meaning. Attributes can be of ordinary, structural, derived and implicit role, representing ordinary object properties, hierarchical structure, generic properties and properties defined implicitly with a specific abstraction.Special attention is paid to the representation of generic object properties, which are described by means of a derived attribute or
constructor.
The constructor enables the description and reevaluation of design object construction process.
Applying classification and inheritance into compiling
Authors: Wu Pei-Chi , Wang Feng-Jian
Published: January 2007

In this paper, we present an approach which integrates the classification and inheritance concepts into both the specification and generation of compiler and compiling process. The nodes in a parse tree are deemed as objects whose properties are defined in a class hierarchy derived from a
restricted
CFG directly. The inheritance in the class hierarchy can help reduce both the coding (or specification) effort for the properties definition and the parse tree for analysis.
Frequency counts, accumulations and cross-tabulations in APL
Authors: Bergquist Gary A.
Published: January 2007

Frequency counts (how many) and accumulations (how much) are everyday programming tasks. Yet, there are no primitive APL functions for solving these problems directly. Instead, you dig into your bag of techniques and use some clever shifting or inner/outer product method to do the job. This paper proposes a primitive syntax for generally computing frequency counts, accumulations and cross-tabulations (which are multidimensional frequency counts and accumulations). The aim of the paper is not to encourage the implementation of a new primitive function; rather, it offers a mental model: a way to view this class of problems. A user-defined function that implements the model is shown on page 28.
Full-screen, scrollable APL2 spreadsheet input/output editor
Authors: Lewis Peter A. W.
Published: January 2007

A full-screen, scrollable, spreadsheet-like editor based on IBM's APL2 32-bit interpreter for 386/486-based microcomputers is described. It is used for entering, examining, analyzing, editing and printing data. Mixed numeric and character arrays can be read in from or written out to formatted DOS files (ASCII) or comma-delimited DOS files. Alternatively, a bulk mode input facility allows for rapid direct data entry, or data can be entered, examined and edited cell-by-cell in the usual way. A facility for coding missing values is also provided. No numerical coding of the data is needed. Columns, rows or blocks of data can be highlighted in a chosen color, shadowed, moved or copied. In addition, APL functions entered on the command line can use the blocks as input or output. The full notational and computational power of APL is available. Major-to-minor (lexicographic) sorts can be performed on selected columns, and conditional or unconditional frequency tabulations and cross-tabulations of selected columns can be performed. Output from these statistical calculations is obtained as a new spreadsheet, or equivalently, as an APL2 matrix. In particular, two-way cross-tabulations of multiple columns are laid out in the spreadsheet like draftsmen's plots to facilitate investigation and explanation of multivariate categorical data.
Typesetting APL with L
A
T
E
X
Authors: Geyer-Schulz Andreas , Matulka Josef , Neumann Gustaf
Published: January 2007

In this paper we present an
APL
publishing system for LAT
E
X which supports typesetting of
APL
publications and documents in a mixed hardware, multiple vendor
APL
environment. It requires minimal maintenance and is in the public domain. The system has two components, the LAT
E
X document style option apl.sty and the APL2TEX front end. apl.sty currently provides the full symbol sets of the
APL
dialects
APL
2/370,
APL
2/PC, Dyalog
APL,
I---
APL,
Sharp
APL,
and
APL
.68000 Levels I and II. All
APL
symbols are constructed with the symbols of the standard LAT
E
X font family. No special fonts are needed. The APL2TEX front end is a workspace containing a preprocessor for converting
APL
objects to LAT
E
X logical document elements. APL2TEX is currently available for
APL
2/370,
APL
2/PC, Dyalog
APL
and
APL
.68000 Levels I and II.
Talking with an APL via DDE
Authors: Halasz Steven J. , Kondrashev Andrei V.
Published: January 2007

Shared variables and auxiliary processors are well-known techniques for connecting alien applications to APL. The use of APL in the PC windowing multitasking environment of MS Windows, which incorporates a messaging model for interprocess communications, requires some new approaches to the implementation of shared variable and auxiliary processor support. This paper presents a shared variable interface to MS Windows graphics written in Microsoft C and a simple charting package called TinyPlot written in Dyalog APL for Windows (Dyalog APL/W). The purpose of this paper is to demonstrate and investigate the Dyalog APL/W shared variable and auxiliary processor facilities, and to offer observations and conclusions about the benefits, limitations, and potential of the Dynamic Data Exchange interface generally.
Extending the two-partner shared variable protocol to
n
partners
Authors: Kolarik Thomas
Published: January 2007

APL as a language has always provided a high level of abstraction to its users. Only in the field of communication have APL channels --- called shared variables --- been restricted to at most two partners. As most distributed applications demand more than two interacting programs, APL users had to apply their own techniques, like client-server, to develop applications that share information among more than two partners. This paper presents a proposal to move the administration of shared memory from application to language level: An extension to the well known shared variable protocol to share memory among more than two partners. Two applications of this distributed shared memory system are presented: A combinatorial optimization problem that is distributed among the machines of a workstation network and an application for students that learn APL in a working group are based upon a prototype implementation of the proposed protocol.
Efficient maximum likelihood estimation of linear models with APL
Authors: Ripley Frank C.
Published: January 2007

Maximum likelihood estimators used in statistics and econometrics have desirable properties, however, due to the complexity of their solution maximum likelihood techniques are not widely used. This paper examines an APL implementation of one of the most efficient algorithms used to estimate the parameters of the univariate ARMA process. The straight-forward use of APL is found to be unacceptable and so a systematic search for optimizations is made. This search results in an approximate solution for the ML estimator, the use of □NA and FORTRAN, and special matrix techniques to increase the efficiency of the algorithm. The matrix techniques used are implementations of sparse, banded, and block diagonal data structures. Additional matrix techniques involve incremental updating of matrices. The effect of these optimizations is to bring the computational cost from an O(N*3) problem to an O(N*1) problem. This translates into a significant reduction in computer requirements. For example, to estimate a three parameter ARMA model with 5000 observations, memory requirements fall from approximately 95 megabytes to 300 kilobytes. Computer time falls from about 6.4 years to under 1 minute.
Identification of parallelism in neural networks by simulation with language J.
Authors: Skurihin Alexei N. , Surkan Alvin J.
Published: January 2007

Neural networks, trained by backpropagation, are designed and described in the language
J,
an

APL

derivative with powerful function encapsulation features. Both the languages
J
[4,6,7] and

APL

[5] help to identify and isolate the parallelism that is inherent in network training algorithms. Non-critical details of data input and derived output processes are de-emphasized by relegating those functions to callable stand-alone modules. Such input and output modules can be isolated and customized individually for managing communication with arbitrary, external storage systems. The central objective of this research is the design and precise description of a neural network training kernel. Such kernel designs are valuable for producing efficient reusable computer codes and facilitating the transfer of neural network technology from developers to users.
Point-wise calculus
Authors: Spunde Walter G.
Published: January 2007

The work of Richard Neidinger implementing automatic differentiation in APL as a vector arithmetic is reformulated and extended. For functions of a single variable, an arithmetic is developed for
function samples,
nested vectors whose components hold the values, at any number of given sample points, of a function and its derivatives up to any specified order. It is argued that, for teaching purposes, this sampling provides a more intuitive introduction to mathematical functions and the rules of calculus than do algebraic formulae and that for certain calculations (such as the computation of polynomial approximations of high degree) the formulation provides superior algorithms for computation. As such, it offers an alternative approach to the teaching of elementary college mathematics.
MEASURE+
Authors: Tang Dong , Iyer Ravishankar K.
Published: January 2007

Most existing dependability modeling and evaluation tools are designed for building and solving commonly used models with emphasis on solution techniques, not for identifying realistic models from measurements. In this paper, a measurement-based dependability analysis package, MEASURE+, is introduced. Given measured data from real systems in a specified format MEASURE+ can generate appropriate dependability models and measures including Markov and semi-Markov models,
k
-out-of-
n
availability models, failure distribution and hazard functions, and correlation parameters. These models and measures obtained from data are valuable for understanding actual error/failure characteristics, identifying system bottlenecks, evaluating dependability for real systems, and verifying assumptions made in analytical models. The paper illustrates MEASURE+ by applying it to the data from a VAXcluster multicomputer system. Models of field failure behavior identified by MEASURE+ indicate that both traditional models assuming failure independence and those few taking correlation into account are not representative of the actual occurrence process of correlated failures.
A Markov-modulated Bernoulli process approximation for the analysis of Banyan Networks
Authors: Meliksetian Dikran S. , Chen C. Y. Roger
Published: January 2007

The Markov-Modulated Bernoulli Process (MMBP) model is used to analyze the delay experienced by messages in clocked, packed-switched Banyan networks with
k
x
k
output-buffered switches. This approach allows us to analyze both single packet messages and multipacket messages with general traffic pattern including uniform traffic, hot-spot traffic, locality of reference, etc. The ability to analyze multipacket messages is very important for multimedia applications. Previous work, which is only applicable to restricted message and traffic patterns, resorts to either heuristic correction factors to artificially tune the model or tedious computational efforts. In contrast, the proposed model, which is applicable to much more general message and traffic patterns, not only is an application of a theoretically complete model but also requires a minimal amount of computational effort. In all cases, the analytical results are compared with results obtained by simulation and are shown to be very accurate.
Asynchronous analysis of parallel dynamic programming
Authors: Lewandowski Gary , Condon Anne , Bach Eric
Published: January 2007

We examine a very simple asynchronous model of parallel computation that assumes the time to compute a task is random, following some probability distribution. The goal of this model is to capture the effects of unexpected delays on processors.
On Local SIGDAs
Authors: Lowell John K.
Published: January 2007

One of the least publicized but no less important activities of SIGDA has been the formation of local SIGDA groups across the country. With a strong, grassroots network in place, the goals and interests of all members can be shared on a local basis. In addition to national meetings like the DAC and ICCAD, and various workshops, the availability of a local SIGDA organization provides another level of ongoing professional interaction. For the national directorate, the network could be used to disseminate information, provide national officer candidates, host regional meetings, and most important, give comments and criticism on SIGDA itself.
HCI Education News
Authors: Gasen Jean B.
Published: January 2007

In August 1988, the ACM SIGCHI Executive Committee voted to authorize a multi-year project to develop a set of curriculum recommendations for education in Human-Computer Interaction. A Curriculum Development Group, established and coordinated by Tom Hewett, met in six face-to-face meetings over the course of two years.
1
In addition, two open SIG meetings at CHI' 89 and CHI'90, a tutorial session at CHI'91 and several volunteer reviewers provided feedback on various drafts of the Curriculum Development Group's efforts.
International Perspectives
Authors: Karat John , Karat Clare-Marie
Published: January 2007

This issue's column features a contribution from Masaaki Kurosu describing the Technical Committee for Human Interface of the Society of Instrument and Control Engineers in Japan. We found it interesting to hear about the organization and activities of this committee, and found the similarities and differences to SIGCHI informative. While the SIGCHI community has had extensive contact with some of the overseas professional societies with similar interests (such as the HCI Specialists group of the British Computer Society), there are many organizations that we know relatively little about. We thank Masaaki for providing this glimpse at an activity in Japan, and will try and include reports of other overseas societies in future columns.
REPORTS FROM CSCW'92
Authors: Bly Sara
Published: January 2007

The ACM Conference on Computer-Supported Cooperative Work (CSCW'92) was held in Toronto, Canada, October 31 to November 4, 1992. Sponsored by ACM SIGCHI and SIGOIS, the conference was focused on "sharing perspectives" especially in bringing together the multiple disciplines of the field. In the next several pages, you will find seven panel and workshop reports that are summaries of discussions not available as part of the conference proceedings.
Canvass committee members sought for ANSI/HFS 100 revision
Authors: Billingsley Pat
Published: January 2007

The first revision of the Human Factors and Ergonomics Society's
American National Standard for Human Factors Engineering of Visual Display Terminal Workstations
(ANSI/HFS 100-1988) is expected to be available for public review and comment in fall 1993. According to ANSI policy, all persons who are materially and directly affected by the standard may comment on the revised document, which must receive majority approval by the canvass committee before it is accepted as a U.S. national standard. The topics covered by the standard include: keyboard and non-keyboard input devices, CRT and flat-panel output devices, the ambient environment of office computer workstations, and office furniture used with computers.
Some closing thoughts about SIGCHI
Authors: Henderson Austin
Published: January 2007

As I turn over the role of SIGCHI Chair to Jim Miller, I would like to offer some thoughts on the state and future of SIGCHI. These thoughts are my own, but they are heavily influenced by the visioning project carried out during the SIGCHI community. This exercise yielded some interesting insights. I recommend it to your attention (instructions at the end). My thoughts are also influenced by the actions and efforts of the SIGCHI executive committees on which I served over the past five years. For example, see the Chair's Column in each Bulletin or the SIGCHI Annual Report that appears elsewhere in this issue.
The productivity paradox; Why hasn't information technology fulfilled its promise?
Authors: Constant David
Published: January 2007

Has information technology failed to Fulfill its promise of significant productivity improvements for industry and for the economy as a whole? If so, what has prevented it and what are the implications for CSCW design and deployment? These questions were addressed by a standing-room-only panel discussion of "The Productivity Paradox" at CSCW'92. The dis- cussion focused on Attewell's paper "Information Technology and the Productivity Paradox". The paper argues that, despite huge investment, the expected huge productivity improvements due to information technology have not been realized. The paper proposes several reasons why. Over the last three years this paper and the issues it raises have generated much controversy and passionate reaction in industry, academia and government.
Commercial products for CSCW
Authors: Lindholm Kristina A.
Published: January 2007

If we had to pick one phrase to sum up the discussion that took place at the CSCW commercial products panel it would be "change takes time" --- change not only in technology but also in the way people behave. All of the panelists remarked that the nature of CSCW products requires change --- in technology, in how people work and in how people think. All of this requires time. We have to be realistic when assessing how long it takes for CSCW products to catch on in the commercial market. Change is happening, it is just happening slowly and on many different levels.
Reports of the workshop on interdisciplinary theory for CSCW design
Authors: Hunt William
Published: January 2007

This report describes the Workshop on Interdisciplinary Theory for CSCW Design which took place on 31 October 1992 during the first day of the ACM 1992 Conference on Computer-Supported Cooperative Work.
Technology and pedagogy for collaborative problem solving as a context for learning
Authors: Koschmann Timothy , Newman Denis , Woodruff Earl , Pea Roy , Rowley Peter
Published: January 2007

This workshop, sponsored jointly by CSCW'92 and the Centre for Applied Cognitive Science at the Ontario Institute for Studies in Education (OISE), was organized to bring together researchers with interests in the emerging area of Computer Support for Collaborative Learning (CSCL). It was held at OISE on the weekend preceding CSCW'92 and was attended by 27 participants from academia and industry.
Agreeing to begin
Authors: Watzman Suzanne
Published: January 2007

Over my career I have created and worked on many identity programs for a wide variety of organizations and companies. Of these, the SIGCHI Identity Project has truly been the most unique and challenging.
Finding maximal subfields
Authors: Landau Susan
Published: January 2007

The problem: Given a field
K
with a finite extension
K
(α),
K
(α) described in terms of the minimal polynomial of α over
K
, find all maximal subfields of
K
(α) containing
K.
(
K
is assumed to be characteristic zero.)
Book review: Formalizing Common Sense: Papers by John McCarthy edited by Vladimir Lifschitz (Ablex, 1990)
Authors: Marek Victor W.
Published: January 2007

Why would one read the papers of masters? There are at least two reasons for doing so. First, by tracing the development of ideas of someone with true insight it is possible to see the roots of various developments, concepts, and even false starts. In short we see how the domain, as we know it today, emerged in the historical process. Second, it is dangerous if one does not know the past. One is prone to fall into the same potholes as the previous generations.
The Turing test is for the birds
Authors: Fostel Gary
Published: January 2007

The comments in
The Economist
re: purpose and value of AI [1] were most refreshing. I cannot resist quoting words to similar effect from my own writing.
Selecting the checkpoint interval in time warp simulation
Authors: Lin Yi-Bing , Preiss Bruno R. , Loucks Wayne M. , Lazowska Edward D.
Published: January 2007

In Time Warp parallel simulation, the state of each process must be saved (checkpointed) regularly in case a rollback is necessary. Although most existing Time Warp implementations checkpoint after every state transition, this is not necessary, and the checkpoint interval is in reality a tuning parameter of the simulation.

Lin and Lazowska[6] proposed a model to derive the optimal checkpoint interval by assuming that the rollback behavior of Time Warp is not affected by the frequency of checkpointing. An experimental study conducted by Preiss et al.[10] indicates that the behavior of rollback is affected by the frequency of checkpointing in general, and that the Lin-Lazowska model may not reflect the real situations in general.

This paper extends the Lin-Lazowska model to include the effect of the checkpoint interval on the rollback behavior. The relationship among the checkpoint interval, the rollback behavior, and the overhead associated with state saving and restoration is described. A checkpoint interval selection algorithm which quickly determines the optimal checkpoint interval during the execution of Time Warp simulation is proposed. Empirical results indicate that the algorithm converges quickly and always selects the optimal checkpoint interval.
An algorithm for minimally latent global virtual time
Authors: Tomlinson Alexander I. , Garg Vijay K.
Published: January 2007

Global virtual time (GVT) is used in distributed simulations to reclaim memory, commit output, detect termination, and handle errors. It is a global function that is computed many times during the course of a simulation. A small GVT latency (delay between its occurrence and detection) allows for more efficient use of resources. We present an algorithm which minimizes the latency, and we prove its correctness. The algorithm is unique in that a target virtual time (TVT) is predetermined by an initiator who then detects when GVT ≥ TVT. This approach eliminates the avalanche effect because the collection phase is spread out over time, and it allows for regular and timely GVT updates. The algorithm does not require messages to be acknowledged, which significantly reduces the message overhead of the simulation. One possible application is with interactive simulators, where regular and timely updates would produce output that is up to date and appears smooth.
On a parallel partitioning technique for use with conservative parallel simulation
Authors: Nandy Biswajit , Loucks Wayne M.
Published: January 2007

The major goal of this work has been to develop an implementation of a parallel partitioning algorithm which is suitable for use in a conservatively synchronized Parallel Discrete Event Simulation (PDES) environment. Effective partitioning is essential for performance and capacity consideration, for any PDES problem. The performance of the partitioning algorithm is very important, to the overall simulation performance. There are two possible approaches to improve performance for the partitioning step: algorithm modifications; and parallelize the partitioning algorithm (Fiduccia and Mattheyses, 1982) is developed. The basic algorithm has been modified, first for parallel execution with a similar quality of final partition; and then further modified to increase the parallelism of the algorithm, at the expense of partition quality.
How using busses in multicomputer programs affects conservative parallel simulation
Authors: Bailey Mary L. , Pagels Michael A. , Wong Kachung Kevin
Published: January 2007

In this paper we consider the effect of using bus interconnection structures on the overheads present in conservative parallel simulations of multicomputer programs. We use a modified version of the Poker Programming Environment to empirically measure the overhead in three parallel algorithms using buses. We discuss the sources of overhead and compare them with those found using point-to-point communication. Preliminary results indicate that the overheads encountered using a bus interconnection structure were not predicted by our previous results using point-to-point communications.
Breathing Time Warp
Authors: Steinman Jeff S.
Published: January 2007

Time Warp
and
Breathing Time Buckets
are two general-purpose optimistic synchronization strategies for supporting parallel discrete-event simulations. However, each one of these approaches has potential fatal shortcomings. Time Warp may exhibit rollback explosions that can cause an avalance of antimessages. Breathing Time Buckets, on the other hand, may not be able to process enough events per synchronization cycle to remain efficient.

A new strategy, called
Breathing Time Warp
, has been developed in the Synchronous Parallel Environment for Emulation and Discrete-Event Simulation (SPEEDES) operating sytem. This new strategy solves both of these problems by mixing the two algorithms together, resulting in the best of both methods.

This paper describes the implementation of the Breathing Time Warp algorithm in SPEEDES, and then shows how this new approach sometimes improves the performance of parallel discrete-event simulations.
Cache management algorithms for flexible filesystems
Authors: Maffeis Silvano
Published: January 2007

Cache management in flexible filesystems deals with the problem of determining a cached file to be replaced when the local cachespace is exhausted. In analogy to virtual memory management, several different algorithms exist for managing cached files. In this paper we simulate the behavior of
First-In-First-Out (FIFO), Least Recently Used (LRU), Least Frequently Used (LFU)
and a variation of LFU we call the
File Length Algorithm (LEN)
from the viewpoint of file access times, cache hit ratios and availability. The results of several simulation runs are presented and interpreted.
Performance management activities within UNIX International
Authors: UNIX International CORPORATE
Published: January 2007

The primary output of the UNIX International Work Group on Performance Measurement is a set of requirements and recommendations to UNIX International and UNIX System Laboratories for the development of standard performance measurement interfaces to the UNIX System. Requirements will be based on the collective, non-vendor specific needs for a standard performance architecture. Currently the lack of this standard causes undue porting and kernel additions by each UNIX System vendor as well as a great variety of approaches to gain the same basic performance insight into the system. Building tools to monitor, display, model, or predict performance or its trends is a frustrating and currently single vendor enterprise. By providing standard data structures, types of performance data gathered, and a common kernel interface to collect this data, the whole UNIX system vendor community along with the UNIX software vendors can develop performance tools which last more than one UNIX release and work on multiple UNIX platforms.
On DO WHILE vs. DO with EXIT
Authors: Reid John
Published: January 2007

This is a response to the article [1] by my namesake in the June 1993 Fortran Forum. He is right to say that DO WHILE `flip-flopped' in and out of the standard, but is wrong to say that at one time it was excluded in favor of control by a stepped variable. The alternative that the committee had in mind was
An integrated framework for quality scientific software development
Authors: Murali P. , Dutta D. , Biswas R. N.
Published: January 2007

The objective of this paper is to present a framework for quality software development in the Scientific Application area. In a scientific application area, the specification and configuration control phases of the development cycle generally do not pose a serious problem. In most cases, a compact and comprehensive specification can be arrived at solely from the field of application. However, support is expected in the development and maintenance phases of the software life cycle. With this assumption, an integrated Fortran Environment and Scientific CASE Tool (FE/SCT) was designed, developed, and implemented for the DOS operating system.
A generic information retrieval system to support interoperability
Authors: Mukhopadhyay Debajyoti
Published: January 2007

Retrieval of information from a database is a basic and vital function that any system is expected to provide. With the growing complexity of information, and with the advent of distributed systems, it has become necessary to process any retrieval request coming from any system which is a part of the distributed environment. This calls for a generic retrieval system supporting interoperability which can formulate the request on the fly. Interoperability is the ability to interconnect software products irrespective of their suppliers and vintages, to provide access to corporate data by any authorized user, and to maintain that interconnection and access over changes in suppliers and vintages. This paper describes such a system which is generic in nature, and at the same time provides a mechanism which supports the mapping of the logical view to physical database implementation supporting interoperability.
Multimodal and multimedia interfaces
Authors: Fähnrich K.-P. , Hanne K.-H.
Published: January 2007

INTERCHI '93 hosted the workshop on multimodal and multimedia human computer interfaces which was co-initiated and co-sponsored by IFIP TC 13: "Human Computer Interaction".
Is designing a neural network application an art or a science?
Authors: Erenshteyn Roman , Foulds Richard , Galuska Scott
Published: January 2007

Both the danger and the attraction of pattern recognition problems lie in their simplicity. When investigators first approach such a problem, they may, with an easiness which borders on carelessness, utilize the methods most familiar to them; and... they sometimes receive satisfactory results. More often, they are haunted by troubles. Only a good understanding of the problem will permit them to solve it. The quality of problem solving depends on the investigator's abilities, experience, knowledge and very often on... fertile imagination. In this paper we will discuss the problems connected with practical neural network application design.
Multinational or International
Authors: Cockton Gilbert
Published: January 2007

An important goal for ACM SIGs is
internationalisation.
But what does internationalisation mean to you? I offer a personal view below. I've written it in a somewhat provocative style, but I hope this provokes reflection rather than annoyance! I've used some Scots English, so we can meet on equal terms.
Book Review: Defying Gravity: The Making of Newton by Markos Kounalakis (Beyond Words Publishing, Inc., 1993)
Authors: Nielsen Jakob
Published: January 2007

This book has been described as
The Soul of a New Machine
meets
A Day in the Life.
Unfortunately, it is neither, and it suffers in comparison with these two insightful works.
Defying Gravity
is a photojournalistic report of the events leading to the often-delayed introduction of the Newton in August 1993. Interestingly, the book arrived about one month after I finally received my Newton and about two months after the last event depicted in the book. Such rapid production of a book is in itself a reflection of modern information technology, though of course it could have been out even faster on the Internet. Basically, the photographer Doug Menuez followed the Newton development, marketing, and management teams through a period of about two years, and his photographs are presented intertwined with a text outlining the six-year history of the project. Unfortunately, the text and photos are poorly integrated, with the pictures and descriptions of the same events often occurring many pages apart without a cross-reference.
Book review: Neural Network Learning and Expert Systems by Stephen L. Gallant (MIT Press, Cambridge, MA, 1993)
Authors: Minior Dorothy , Lewis Lundy
Published: January 2007

There is an abundance of literature on Neural Networks (NNs). However, it is hard to find a text on NNs that provides a happy balance among good pedagogy, theory, and practice. For example, most introductory NN courses are taught with a collection of loosely related papers, excerpts from books, or software packages. A novice attempting to learn the subject without a good instructor inevitably becomes lost in an array of inconsistent terminology, complicated mathematics, and diverse methodologies and usually does not obtain a firm grasp of the basic foundations of the subject. Steve Gallant's book "Neural Network Learning and Expert Systems" is a good effort towards alleviating these problems. In addition, the book introduces a method to integrate the best features of NNs and expert systems (ESs). The goals of the book are (1) to provide a systematic development of NN learning algorithms suitable for researchers and students and (2) to present NN expert systems. The former goal is largely met and thus renders the book well-suited for self-directed study or for primary reading in a graduate or upper-level undergraduate NN course. The latter goal is met also, although the book lacks sufficient comparison with alternative approaches to the integration of NNs and ESs.
Book review: Encyclopedia of Computer Science, Third Edition, edited by Anthony Ralston and Edwin I). Reilly (Van Nostrand Reinhold, 1993)
Authors: Finkel David
Published: January 2007

The new edition of the well-regarded
Encyclopedia of Computer Science
is truly impressive. It's over 1500 pages long, with over 700 articles. While some articles just define a term in a few paragraphs, others are much more extensive: the article on operating systems is 25 pages long. There's even a twelve-page section of full-color illustrations, with the expected pictures of computer graphics, fractals, and scientific visualization, as well as an unexpected section of illustrations of postage stamps dealing with computing.
Reintroducing APL for teaching univariate and multivariate statistics
Authors: Hunka Steve
Published: January 2007

In teaching univariate and multivariate statistical analysis with an emphasis on the general linear model to graduate students in the social sciences, APL provides an excellent vehicle by which the concepts and operations of matrix algebra can be illustrated and explored. Functions written in APL to carry out the computations of the statistical models which provide for display of intermediate results allow students to check the adequacy of the final results and to confirm numerically the characteristics of the various models. When the objectives of a course are to provide for a basic understanding of the linear models, the use of APL is considered superior to the use of most commercial statistical packages.
APL2 implementation of a new definition of consistency of pairwise comparisons
Authors: Herman Michael W. , Koczkodaj Waldemar W.
Published: January 2007

A set of APL2 functions is presented for a new definition of consistency of pairwise comparisons. By calculating an inconsistency for each comparison, these functions locate the source of inconsistency and can thus be used to improve relative judgements.
Single versus multiple inheritance in object oriented programming
Authors: Singh Ghan Bir
Published: January 2007

Inheritance is one of the key elements of Object oriented programming. Inheritance is characterized as single or multiple depending on the number of classes a class can inherit from. Single inheritance is simple but restrictive. Multiple inheritance on the other hand is complex but allows a more natural definition of relationships between classes. There has been a significant amount of discussion on the value of multiple inheritance over single inheritance considering the complexity multiple inheritance adds. This paper reviews the two types of inheritance and examines their benefits. The paper then examines the issues and objections that have been raised on the two inheritance mechanisms. Graph, Linear, and Tree oriented implementations of multiple inheritance are reviewed to see how multiple inheritance issues are handled by various object oriented languages.
Accurate modeling of the hybrid hash join algorithm
Authors: Patel Jignesh M. , Carey Michael J. , Vernon Mary K.
Published: January 2007

The join of two relations is an important operation in database systems. It occurs frequently in relational queries, and join performance is a significant factor in overall system performance. Cost models for join algorithms are used by query optimizers to choose efficient query execution strategies. This paper presents an efficient analytical model of an important join method, the hybrid hash join algorithm, that captures several key features of the algorithm's performance—including its intra-operator parallelism, interference between disk reads and writes, caching of disk pages, and placement of data on disk(s). Validation of the model against a detailed simulation of a database system shows that the response time estimates produced by the model are quite accurate.
An empirical study of a highly available file system
Authors: Noble Brian D. , Satyanarayanan M.
Published: January 2007

In this paper we present results from a six-month empirical study of the high availability aspects of the Coda File System. We report on the service failures experienced by Coda clients, and show that such failures are masked successfully. We also explore the effectiveness and resource costs of key aspects of
server replication
and
disconnected operation
, the two high availability mechanisms of Coda. Wherever possible, we compare our measurements to simulation-based predictions from earlier papers and to anecdotal evidence from users. Finally, we explore how users take advantage of the support provided by Coda for mobile computing.
The expected lifetime of “single-address-space” operating systems
Authors: Kotz David , Crow Preston
Published: January 2007

Trends toward shared-memory programming paradigms, large (64-bit) address spaces, and memory-mapped files have led some to propose the use of a single virtual-address space, shared by all processes and processors. Typical proposals require the single address space to contain all process-private data, shared data, and stored files. To simplify management of an address space where stable pointers make it difficult to re-use addresses, some have claimed that a 64-bit address space is sufficiently large that there is no need to ever re-use addresses. Unfortunately, there has been no data to either support or refute these claims, or to aid in the design of appropriate address-space management policies. In this paper, we present the results of extensive kernel-level tracing of the workstations in our department, and discuss the implications for single-address-space operating systems. We found that single-address-space systems will not outgrow the available address space, but only if reasonable space-allocation policies are used, and only if the system can adapt as larger address space becomes available.
An adaptive memory management protocol for Time Warp parallel simulation
Authors: Das Samir R. , Fujimoto Richard M.
Published: January 2007

It is widely believed that Time Warp is prone to two potential problems: an excessive amount of wasted, rolled back computation resulting from “rollback thrashing” behaviors, and inefficient use of memory, leading to poor performance of virtual memory and/or multiprocessor cache systems. An adaptive mechanism is proposed based on the Cancelback memory management protocol that dynamically controls the amount of memory used in the simulation in order to maximize performance. The proposed mechanism is adaptive in the sense that it monitors the execution of the Time Warp program,
automatically
adjusts the amount of memory used to reduce Time Warp overheads (fossil collection, Cancelback, the amount of rolled back computation, etc.) to a manageable level. The mechanism is based on a model that characterizes the behavior of Time Warp programs in terms of the flow of memory buffers among different buffer pools. We demonstrate that an implementation of the adaptive mechanism on a Kendall Square Research KSR-1 multiprocessor is effective in automatically maximizing performance while minimizing memory utilization of Time Warp programs, even for dynamically changing simulation models.