Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 19201 - 19230 of 20574

Full-Text Articles in Entire DC Network

Minitel Versus The Internet In France, Ruthie Kerr Jan 1999

Minitel Versus The Internet In France, Ruthie Kerr

Capstone Research Projects

No abstract provided.


The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim Jan 1999

The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim

Northeast Parallel Architecture Center

Exploiting our experience developing the WebFlow system, we designed the Gateway system to provide seamless and secure access to computational resources at ASC MSRC. The Gateway follows our commodity components strategy, and it is implemented as a modern three-tier system. Tier 1 is a high-level front end for visual programming, steering, run-time data analysis and visualization that is built on top of the Web and OO commodity standards. Distributed object-based, scalable, and reusable Web server and Object broker middleware forms Tier 2. Back-end services comprise Tier 3. In particular, access to high-performance computational resources is provided by implementing the emerging …


Thoughts On The Structure Of An Mpj Reference Implementation, Mark Baker, Bryan Carpenter Jan 1999

Thoughts On The Structure Of An Mpj Reference Implementation, Mark Baker, Bryan Carpenter

Northeast Parallel Architecture Center

We sketch a proposed reference implementation for MPJ, the Java Grande Forum's MPI-like message-passing API [9, 3]. The proposal relies heavily on RMI and Jini for finding computational resources, creating slave processes, and handling failures. User-level communication is implemented efficiently directly on top of Java sockets.


The Gateway System: Uniform Web Based Access To Remote Resources, Tomasz Haupt, Erol Akarsu, Geoffrey C. Fox, Alexey Kalinichenko Jan 1999

The Gateway System: Uniform Web Based Access To Remote Resources, Tomasz Haupt, Erol Akarsu, Geoffrey C. Fox, Alexey Kalinichenko

Northeast Parallel Architecture Center

Exploiting our experience developing the WebFlow system, we designed the Gateway system to provide seamless and secure access to computational resources at ASC MSRC. The Gateway follows our commodity components strategy, and it is implemented as a modern three-tier system. Tier 1 is a high-level front-end for visual programming, steering, run-time data analysis and visualization, built on top of the Web and OO commodity standards. Distributed object-based, scalable, and reusable Web server and Object broker middleware forms Tier 2. Back-end services comprise Tier 3. In particular, access to high performance computational resources is provided by implementing the emerging standard for …


Formal Analysis Of A Secure Communication Channel: Secure Core-Email Protocol, Dan Zhou, Shiu-Kai Chin Jan 1999

Formal Analysis Of A Secure Communication Channel: Secure Core-Email Protocol, Dan Zhou, Shiu-Kai Chin

Electrical Engineering and Computer Science - All Scholarship

To construct a highly-assured implementation of secure communication channels we must have clear definitions of the security services, the channels, and under what assumptions these channels provide the desired services. We formally define secure channel services and develop a detailed example. The example is a core protocol common to a family of secure email systems. We identify the necessary properties of cryptographic algorithms to ensure that the email protocol is secure, and we verify that the email protocol provides secure services under these assumptions. We carry out the definitions and verifications in higher-order logic using the HOL theorem-prover. All our …


Performance Analysis Of Csma And Btma Protocols In Multihop Networks: Part Ii - Multiple Channel Case, Lin Wu, Pramod K. Varshney Jan 1999

Performance Analysis Of Csma And Btma Protocols In Multihop Networks: Part Ii - Multiple Channel Case, Lin Wu, Pramod K. Varshney

Electrical Engineering and Computer Science - All Scholarship

Busy tone multiple access protocols have been used in multihop networks to reduce the effect of the hidden terminal problem. This paper demonstrates another approach to reduce the effect of the hidden terminal problem namely the use of multiple channel schemes. A protocol that uses both the busy tone and the multiple channel techniques achieves the best performance. Using a Markov chain model and an approximation, the throughput performance of the multiple channel nonpersistent CSMA protocol and the multiple channel conservative BTMA protocol in a large network is evaluated and compared. The results show that the multichannel CSMA and BTMA …


Lewis Carroll: Author, Mathematician, And Christian, David L. Neuhouser Jan 1999

Lewis Carroll: Author, Mathematician, And Christian, David L. Neuhouser

ACMS Journal 2004

Although a Christian, an author, and a mathematician, Charles Letwidge Dodgson (better known as Lewis Carroll) wrote very few works in which these three aspects of his person was present. The only examples of him merging these interests are in Sylvie and Bruno and Sylvie and Bruno Concluded. This paper will explore what motivated him to make these works and whether or not they were successful.


Continuous Models Of Computation For Logic Programs: Importing Continuous Mathematics Into Logic Programming's Algorithmic Foundations, Howard A. Blair, Fred Dushin, David W. Jakel, Angel J. Rivera, Metin Sezgin Jan 1999

Continuous Models Of Computation For Logic Programs: Importing Continuous Mathematics Into Logic Programming's Algorithmic Foundations, Howard A. Blair, Fred Dushin, David W. Jakel, Angel J. Rivera, Metin Sezgin

Electrical Engineering and Computer Science - All Scholarship

Logic programs may be construed as discrete-time and continuous-time dynamical systems with continuous states. Techniques for obtaining explicit formulations of such dynamical systems are presented and the computational performance of examples is presented. Extending 2-valued and n-valued logic to continuousvalued logic is shown to be unique, up to choosing the representations of the individual truth values as elements of a continuous field, provided that lowest degree polynomials are selected. In the case of 2-valued logic, the constraint that enables the uniqueness of the continualization is that the Jacobian matrices of the continualizations of the Boolean connectives have only affine entries. …


Truce: Agent Coordination Through Concurrent Interpretation Of Role-Based Protocols, Wilfred C. Jamison, Douglas Lea Jan 1999

Truce: Agent Coordination Through Concurrent Interpretation Of Role-Based Protocols, Wilfred C. Jamison, Douglas Lea

Electrical Engineering and Computer Science - All Scholarship

Established protocols for coordination are essential for implementing joint-action activities among collaborating software agent. Most existing agents, however, are designed only to support static protocols, which limit their interaction domain to specific sets of agents. We develop an agent collaboration framework for open systems that enables an agent to expand its acquaintance set and to adapt to various coordination protocols dynamically. This is achieved through writing coordination scripts that are interpreted at collaboration time. We developed a role-based coordination language for writing these scripts, where the coordination mechanism used is the concurrent interpretation of a single script by the participants …


A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee Jan 1999

A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee

Electrical Engineering and Computer Science - All Scholarship

Global locality optimization is a technique for improving the cache performance of a sequence of loop nests through a combination of loop and data layout transformations. Pure loop transformations are restricted by data dependences and may not be very successful in optimizing imperfectly nested loops and explicitly parallelized programs. Although pure data transformations are not constrained by data dependences, the impact of a data transformation on an array might be program-wide; that is, it can affect all the references to that array in all the loop nests. Therefore, in this paper we argue for an integrated approach that employs both …


Performance Surface Prediction For Wan-Based Clusters, Mark J. Clement, J. Kelly Flanagan, Glenn M. Judd, Bryan S. Morse, Joy L. Peterson Jan 1999

Performance Surface Prediction For Wan-Based Clusters, Mark J. Clement, J. Kelly Flanagan, Glenn M. Judd, Bryan S. Morse, Joy L. Peterson

Faculty Publications

The last five years have been a period of exponential growth in the number of machines connected to the Internet and the speed at which these machines communicate. The infrastructure is now in place to consider a nationwide cluster of workstations as a viable parallel processing platform. In order to achieve acceptable performance on this kind of a machine, performance prediction tools must provide information on where to place computational objects. Incorrect object placement can result in poor performance and congestion in the network. This research develops a new paradigm for predicting performance in the Wide Area Network (WAN) based …


Benchmarks And Standards For The Evaluation Of Parallel Job Schedulers, Steve J. Chapin, Walfredo Cirne, Dror G. Feitelson, James Patton Jones Jan 1999

Benchmarks And Standards For The Evaluation Of Parallel Job Schedulers, Steve J. Chapin, Walfredo Cirne, Dror G. Feitelson, James Patton Jones

Electrical Engineering and Computer Science - All Scholarship

The evaluation of parallel job schedulers hinges on the workloads used. It is suggested that this be standardized, in terms of both format and content, so as to ease the evaluation and comparison of different systems. The question remains whether this can encompass both traditional parallel systems and metacomputing systems. This paper is based on a panel on this subject that was held at the workshop, and the ensuing discussion; its authors are both the panel members and participants from the audience. Naturally, not all of us agree with all the opinions expressed here...


Webhla - An Interactive Multiplayer Environment For High Performance Distributed Modeling And Simulation, Geoffrey C. Fox, Wojtek Furmanski, Subhash Nair, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal Jan 1999

Webhla - An Interactive Multiplayer Environment For High Performance Distributed Modeling And Simulation, Geoffrey C. Fox, Wojtek Furmanski, Subhash Nair, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal

Northeast Parallel Architecture Center

The process of integrating DoD Modeling and Simulation paradigms around the new HLA/RTI standards proceeds in parallel with the onset of new Object Web standards for distributed objects and componentware, emergent at the crossroads of CORBA, DCOM, Java, and XML based distributed object technologies. We describe here our WebHLA approach which integrates both trends by offering Object Web based implementation of the HLA framework. WebHLA follows a three-tier architecture including: a) Web / Commodity based interactive simulation authoring and runtime front-ends given by Java applets or DirectX multiplayers; b) software bus in the middleware, given by Object Web RTI i.e. …


Multiple Stochastic Learning Automata For Vehicle Path Control In An Automated Highway System, Cem Unsal, Pushkin Kachroo, John S. Bay Jan 1999

Multiple Stochastic Learning Automata For Vehicle Path Control In An Automated Highway System, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

This paper suggests an intelligent controller for an automated vehicle planning its own trajectory based on sensor and communication data. The intelligent controller is designed using the learning stochastic automata theory. Using the data received from on-board sensors, two automata (one for lateral actions, one for longitudinal actions) can learn the best possible action to avoid collisions. The system has the advantage of being able to work in unmodeled stochastic environments, unlike adaptive control methods or expert systems. Simulations for simultaneous lateral and longitudinal control of a vehicle provide encouraging results


The World Wide Web, H. Berghel, Doug Blank Jan 1999

The World Wide Web, H. Berghel, Doug Blank

Computer Science Faculty Research and Scholarship

No abstract provided.


Radical Artificial Intelligence: A Postmodern Approach, Doug Blank Jan 1999

Radical Artificial Intelligence: A Postmodern Approach, Doug Blank

Computer Science Faculty Research and Scholarship

No abstract provided.


Multi-User Domain Object Oriented (Moo) As A High School Procedure For Foreign Language Acquisition, James A. Backer Jan 1999

Multi-User Domain Object Oriented (Moo) As A High School Procedure For Foreign Language Acquisition, James A. Backer

CCAC Theses and Dissertations

Foreign language students experience added difficulty when they are isolated from native speakers and from the culture of the target language. It has been posited that MOOs (Multiuser domain Object Oriented) may help to overcome the geographical isolation of these students. MOOs are Internet-based virtual worlds in which people from all over the real world meet for synchronous textual conversations and can interact with asynchronous textual objects found there. Students who enjoy a MOO site may identify with its virtual target language community and find integrative motivation which the literature suggests is necessary for advanced language acquisition.

This study focused …


The Use Of Cooperative Groups In Learning How To Use New Software Programs, James R. Grunwald Jan 1999

The Use Of Cooperative Groups In Learning How To Use New Software Programs, James R. Grunwald

CCAC Theses and Dissertations

Many teachers lament the fact that they often need to spend too much classroom time training students how to use a particular software program before their students can use it effectively as a tool to complete other course work. Also, after completing the training process, too many students still have not mastered the basics of how to use the program effectively. The purpose of this research was to increase understanding of how the use of cooperative groups during new software training affects both the mastery of the basics of program use, as well as the amount of time needed to …


International Usability, Design Guidelines And Effectiveness Of A World Wide Web-Based Instructional Program For High School Students In A Cross-Culture Learning Environment, Hajime Hayakawa Jan 1999

International Usability, Design Guidelines And Effectiveness Of A World Wide Web-Based Instructional Program For High School Students In A Cross-Culture Learning Environment, Hajime Hayakawa

CCAC Theses and Dissertations

The recent growth of the Internet and the World Wide Web (WWW) has resulted in a vast array of on-line courseware and educational Web sites. Unfortunately, as a large percentage of this information is written in English, non-English speakers are unable to access it. Information written in other languages is likewise unavailable to many native English speakers. Therefore, in order to maximize the usefulness of educational material on the Web, it is necessary to design and implement cross-cultural, bilingual or multilingual Web sites and instructional programs.

This study was designed to contribute to the area of bilingual learning on the …


Linking Printed Books To Computerized Speech, Edward D. Crook Jan 1999

Linking Printed Books To Computerized Speech, Edward D. Crook

CCAC Theses and Dissertations

Adult students who experience difficulties in comprehending written (printed) language frequently are limited in their scholastic development and possible employment opportunities. These individuals, who represent a growing segment of the learning disabled population, include poor readers and dyslexics and they routinely seek help and remediation through various educational techniques. One remediation technique often used is "books on tape". Through books on tape, recorded spoken text is presented in a sequential manner to the remedial reader as he or she is reading the corresponding printed document. This dissertation reviewed the books on tape paradigm, and through the use of current computer …


Mpijava: An Object-Oriented Java Interface To Mpi, Mark Baker, Bryan Carpenter, Geoffrey C. Fox, Sung Hoon Ko Jan 1999

Mpijava: An Object-Oriented Java Interface To Mpi, Mark Baker, Bryan Carpenter, Geoffrey C. Fox, Sung Hoon Ko

Northeast Parallel Architecture Center

A basic prerequisite for parallel programming is a good communication API. The recent interest in using Java for scientific and engineering application has led to several international efforts to produce a message passing interface to support parallel computation. In this paper we describe and then discuss the syntax, functionality and performance of one such interface, mpiJava, an object-oriented Java interface to MPI. We first discuss the design of the mpiJava API and the issues associated with its development. We then move on to briefly outline the steps necessary to 'port' mpiJava onto a range of operating systems, including Windows NT, …


Building Distributed Systems For The Pragmatic Object Web, Geoffrey C. Fox, Wojtek Furmanski, Tomasz Haupt Jan 1999

Building Distributed Systems For The Pragmatic Object Web, Geoffrey C. Fox, Wojtek Furmanski, Tomasz Haupt

Northeast Parallel Architecture Center

We review the growing power and capability of commodity computing and communication technologies largely driven by commercial distributed information systems. These systems are built from CORBA, Microsoft's COM, JavaBeans, and rapidly advancing Web approaches. One can abstract these to a three-tier model with largely independent clients connected to a distributed network of servers. The latter host various services including object and relational databases and of course parallel and sequential computing. High performance can be obtained by combining concurrency at the middle server tier with optimized parallel back end services. The resultant system combines the needed performance for large-scale HPCC applications …


Mpijava 1.2: Api Specification, Bryan Carpenter, Geoffrey C. Fox, Sung-Hoon Ko, Sang Lim Jan 1999

Mpijava 1.2: Api Specification, Bryan Carpenter, Geoffrey C. Fox, Sung-Hoon Ko, Sang Lim

Northeast Parallel Architecture Center

This document defines the API of mpiJava, a Java language binding for MPI 1.1. The document is not a standalone specification of the behaviour of MPI--it is meant to be read in conjunction with the MPI standard document [2]. Subsections are laid out in the same way as in the standard document, to allow cross-referencing. Where the mpiJava binding makes no significant change to a particular section of the standard document, we will just note here that there are no special issues for the Java binding. This does not mean that the corresponding section of the standard is irrelevant to …


Using Webhla To Integrate Hpc Fms Modules With Web/Commodity Based Distributed Object Technologies Of Corba, Java, Com And Xml, Geoffrey C. Fox, Wojtek Furmanski, Ganesh Krishnamurthy, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal, Krishnan Rangarajan, Ankur Sood Jan 1999

Using Webhla To Integrate Hpc Fms Modules With Web/Commodity Based Distributed Object Technologies Of Corba, Java, Com And Xml, Geoffrey C. Fox, Wojtek Furmanski, Ganesh Krishnamurthy, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal, Krishnan Rangarajan, Ankur Sood

Northeast Parallel Architecture Center

HLA standards for interoperability between various DoD Modeling and Simulation paradigms are being enforced in parallel with the rapid onset of new Object Web / Commodity standards for distributed objects and componentware, emergent at the crossroads of CORBA, COM, Java, and XML technologies. WebHLA explores synergies between and integrates both trends by offering Object Web based implementation of the HLA framework. Our goal is to deliver a uniform platform that facilitates conversion of legacy codes to and development of new codes in compliance with HLA, HPC and Object Web standards. We outline here the overall design of WebHLA, we summarize …


Internetics: Technologies, Applications And Academic Field, Or, Parallel Computing And Computational Science Do Not Quite Work, Geoffrey C. Fox Jan 1999

Internetics: Technologies, Applications And Academic Field, Or, Parallel Computing And Computational Science Do Not Quite Work, Geoffrey C. Fox

Northeast Parallel Architecture Center

Ten years ago, we were all sure that parallel computing technology and the interdisciplinary academic field of computational science would be center pieces of both academic and economic growth. We show that this insight was, in principle, correct but was an incomplete vision for large-scale computation implies both increased computer power and increasing numbers of users and applications. Parallel computing undoubtedly works on essentially all problems, but we were unable to produce deployable software systems. Further, few industries could achieve adequate return to justify investment in parallel computers, except in a few areas such as databases. Computational science is the …


A Hierarchical Analysis Approach For High Performance Computing And Communication Applications, Salim Hariri, Pramod Varshney, Luying Zhou, Vinod V. Menon, Shihab Ghaya Jan 1999

A Hierarchical Analysis Approach For High Performance Computing And Communication Applications, Salim Hariri, Pramod Varshney, Luying Zhou, Vinod V. Menon, Shihab Ghaya

Electrical Engineering and Computer Science - All Scholarship

The proliferation of high performance computers and high-speed networks has made parallel and distributed computing feasible and cost-effective on High Performance Computing and Communication Systems (HPCC). However, the design, analysis and development of parallel and distributed applications on such computing systems are still very challenging tasks. Therefore, there is a great need for an integrated multilevel analysis methodology to assist in designing and analyzing the performance of both existing and proposed systems. Currently, there are no comprehensive analysis methods that address such diverse needs. This paper presents a three-level hierarchical modeling approach for analyzing the end-to-end performance of an application …


Determination Of The Lep Centre-Of-Mass Energy From Zγ Events, R. Barate, Manoj Thulasidas Jan 1999

Determination Of The Lep Centre-Of-Mass Energy From Zγ Events, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A study of events with photons and missing energy has been performed with the data sample obtained with the ALEPH detector at centre-of-mass energies from 161 to 184 GeV, corresponding to a total integrated luminosity of about 80 pb−1. The measured distributions are in agreement with Standard Model predictions, leading to constraints on WWγ gauge coupling parameters ∆κγ and λγ. The results from the fit to the cross sections and to the energy and angular distributions of the photons are: ∆κγ = 0.05+1.15 −1.10(stat)±0.25(syst) λγ = −0.05+1.55 −1.45(stat)±0.30(syst).


An Intelligent Editor For Natural Language Processing Of Unrestricted Text, Demetrios George Glinos Jan 1999

An Intelligent Editor For Natural Language Processing Of Unrestricted Text, Demetrios George Glinos

Retrospective Theses and Dissertations

The understanding of natural language by computational methods has been a continuing and elusive problem in artificial intelligence. In recent years there has been a resurgence in natural language processing research. Much of this work has been on empirical or corpus-based methods which use a data-driven approach to train systems on large amounts of real language data. Using corpus-based methods, the performance of part-of-speech (POS) taggers, which assign to the individual words of a sentence their appropriate part of speech category (e.g., noun, verb, preposition), now rivals human performance levels, achieving accuracies exceeding 95%. Such taggers have proved useful as …


A Study Of Single W Production In E+E- Collisions At √S = 161-183 Gev, R. Barate, Manoj Thulasidas Jan 1999

A Study Of Single W Production In E+E- Collisions At √S = 161-183 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Single W production is studied in the data recorded with the ALEPH detector at LEP at centre-of-mass energies between 161 and 183 GeV. The cross section is measured to be σw = 0.41 ± 0.17(stat.) ± 0.04(syst.) pb at 183 GeV, consistent with the Standard Model expectation. Limits on non-standard WWγ couplings are deduced as -1.6 γ γ = 0) and -1.6 γ γ = 1) at 95% C.L. A search for effectively invisible decays of the W boson in W pair production is performed, leading to an upper limit on the branching ratio of 1.3% (Γinv = 27 MeV) …


Monitoring The Stability Of The Aleph Vertex Detector, G. Sguazzoni, Manoj Thulasidas Jan 1999

Monitoring The Stability Of The Aleph Vertex Detector, G. Sguazzoni, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements. In particular, the laser system has been used to monitor short-term temperature-related effects and long-term movements. These results and a description of the laser-based alignment correction applied to the 1998 data are presented.