Digital Commons Network^™

The Recursive Multi-Threaded Software Life-Cycle, Scott James Simon

Theses Digitization Project

No abstract provided.

International Student Services Opportunity Database (Issodb), Sailaja Malireddy

Theses Digitization Project

No abstract provided.

A Study Of User Level Scheduling And Software Caching In The Educational Interactive System, Kaoru Tsunoda

Theses Digitization Project

No abstract provided.

Scis Networking - January 1997, Nova Southeastern University

CCIS Networking / SCIS Networking magazines

No abstract provided.

Mathematics And Values: Can Philosophy Guide Projects?, Michael H. Veatch

ACMS Journal 2004

The philosophy of mathematics has provided insight on questions of foundations and mathematical truth; however, it has not been very fruitful in guiding the practice of mathematics. This paper attempts to find points of contact between a Christian worldview and the choice of mathematical projects and methods. Three areas are considered: (i) dubitability in current research, (ii) the intrinsic value of contemporary mathematics to contemporary society, and (iii) the affirmation of human value in the use of mathematics. Finally, a framework for valuing mathematics is proposed as an encouragement to think more deeply about how a Christian might choose a …

Genetic Algorithms For The Extended Gcd Problem, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

We present several genetic algorithms for solving the extended greatest common divisor problem. After defining the problem and discussing previous work, we will state our results.

Webflow - A Visual Programming Paradigm For Web/Java Based Coarse Grain Distributed Computing, Dimple Bhatia, Vanco Burzevski, Maja Camuseva, Geoffrey C. Fox

Northeast Parallel Architecture Center

We present here the recent work at NPAC aimed at developing WebFlow---a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We …

Privacy Issues Dealing With Technology : A Review Of The Literature, Kimberly S. Mccoy

Graduate Research Papers

The sophisticated applications of technology are expanding everyday. Unfortunately, so are the many concerns individuals in society are having about their right to privacy. The actual regulations dealing with one's right to privacy has not expand as rapidly as the applications of technology. Individuals using various types of technology are under the assumption their activities are private; however, this is not the case. It does not seem to matter if you are using a computer for communications work, school, or in the "privacy" of your own home, there is absolutely no privacy when dealing with this type of technology.

This …

Adaptive Multicast Routing In Wormhole Networks, Ran Libeskind-Hadas, Tom Hehre '96, Andrew Hutchings '98, Mark Reyes '98, Kevin Watkins '97

All HMC Faculty Publications and Research

Multicast communication has applications in a number of fundamental operations in parallel computing. An effective multicast routing algorithm must be free from both livelock and deadlock while minimizing communication latency. We describe two classes of multicast wormhole routing algorithms that employ the multi-destination wormhole hardware mechanism proposed by Lin et al. [12] and Panda et al. [17]. Specific examples of these classes of algorithms are described and experimental results suggests that such algorithms enjoy low communication latencies across a range of network loads.

Mobile Unity: A Language And Logic For Concurrent Mobile Systems, Peter J. Mccann, Gruia-Catalin Roman

All Computer Science and Engineering Research

Traditionally, a distributed system has been viewed as a collection of fixed computational elements connected by a static network. Prompted by recent advances in wireless communications rechnology, the emerging field of mobile computing is challenging these assumptions by providing mobile hosts with connectivity that may change over time, raising the possibility that hosts may be called upon to operate while only weakly connected to or while completely disconnected from other hosts. We define a concurrent mobile system as one where independently executing coponents may migrate through some space during the course of the computation, and where the pattern of connectivity …

Principles For Developing And Measuring High-Performance Web Servers Over Atm, James C. Hu, Sumedh Mungee, Douglas C. Schmidt

All Computer Science and Engineering Research

High-performance Web servers are essential to meet the growing demands of the Internet. Satisfying these demands requires a thorough understanding of the key factors that affect Web server performance. This paper provides three contributions to the design, implementation, and evaluation of high-performance Web servers. First, we report the results of a comprehensive empirical study of popular high-performance Web servers (such as Apache, Netscape Enterprise, PHTTPD, and Zeus) over high-speed ATM networks. This study illustrates their relative performance and identifies their performance bottlenecks. To measure performance accurately, we developed a new benchmarking technique that subjects Web servers to varying connection frequencies. …

Building Interactive Distributed Applications In C++ With The Programmers' Playground, Kenneth J. Goldman, Joe Hoffert, T. Paul Mccartney, Jerome Plun, Todd Rogers

All Computer Science and Engineering Research

The objective of The Programmers' Playground, described in this manual, is to provide a development environment and underlying support for end-user construction of distributed multimedia applications from reusable self-describing software components. Playground provides a set of software tools and a methodology for simplifying the design and construction of applications that interact with each other and with people in a distributed computer system. This manual explains how to write interactive distributed applications using Playground. The only background necessary to get started is an understanding of basic data structures and control constructs in C++. If you already know C++, then with the …

Dynamic Flow Switching: A New Communication Service For Atm Networks, Qiyong Bian, Kohei Shimoto, Jonathan Turner

All Computer Science and Engineering Research

This paper presents a new communication service for ATM networks that provides one-way, adjustable rate, on-demand communication channels. The proposed dynamic flow service is designed to operate within a multi-service cell switched network that supports both conventional switched virtual circuits and IP packet routing and is designed to complement those services. It is particularly well suited to applications that transmit substantial amounts of data (a few tens of kilobytes or more) in fairly short time periods (up to a few seconds). Much of the current world-wide web traffic falls within this domain. Like IP packet networks, the new service permits …

Replication Of The First Controlled Experiment On The Usefulness Of Design Patterns: Detailed Description And Evaluation, Lutz Prechelt, Barbara Unger, Douglas Schmidt

All Computer Science and Engineering Research

Advocates of software design patterns claim that using design patterns improves communication between software developers. The controled experiment that we describe in this report tests the hypothesis that software maintainers of well-structured, well-documented software containing design patterns can make changes (1) faster and (2) with less errors if the use of patterns is explicitly documented in the software. The experiment was performed with 22 participants of a university course on C++ and design patterns; it is similar to a previous experiment performed in Karlsruhe. For one of the two experiment tasks the experiment finds that both hypotheses appear to be …

An Algorithm For Message Delivery In A Micromobility Environment, Amy L. Murphy, Gruia-Catalin Roman, George Varghese

All Computer Science and Engineering Research

With recent advances in wireless communication and the ubiquity of laptops, mobile computing has become an important research area. An essential problem in mobile computing is the delivery of a message from a source to either a single mobile node, unicast, or to a group of mobile nodes, multicast. Standard solutions proposed for macromobility (Mobile IP) and micromobility (cellular phones) for the unicast problem rely on tracking the mobile node. Tracking solutions scale badly when mobile nodes move frequently, and do not generalize well to multicast delivery. Our paper proposes a new message delivery algorithm for micromobility based on a …

An Introduction To Mobile Unity, Gruia-Catalin Roman, Peter J. Mccann

All Computer Science and Engineering Research

Traditionally, a distributed system has been viewed as a collection of fixed computational elements connected by a static network. Prompted by recent advances in wireless communications rechnology, the emerging field of mobile computing is challenging these assumptions by providing mobile hosts with connectivity that may change over time, raising the possibility that hosts may be called upon to operate while only weakly connected to or while completely disconnected from other hosts. We define a concurrent mobile system as one where independently executing coponents may migrate through some space during the course of the computation, and where the pattern of connectivity …

Terabit Burst Switching, Jonathan S. Turner

All Computer Science and Engineering Research

This report summarizes the results of an architectural study on Terabit Burst Switching. The purpose of this study was to explore alternative architectures for very high performance switching for data communication, using a combination of optical and electronic technologies. We explore two alternative implementations of the burst switching concept in detail, one using a hybrid architecture with an electronic core, and an integrated architecture using an all optical data path. We also briefly discuss an approach using optical TDM. Our results show that using the hybrid architecture, it is feasible to construct systems with aggregate capacities of tens of terabits …

The Design And Performance Of A Real-Time Corba Event Service, Timothy H. Harrison, David L. Levine, Douglas C. Schmidt

All Computer Science and Engineering Research

The CORBA Event Service provides a flexible model for asynchronous communication among objects.However, the standard CORBA Event Service specification lacks important features required by real-time applications. For instance, operational flight programs for fighter aircraft have complex real-time processing requirements. This paper describes the design and performance of an object-oriented, real-time implementation of the CORBA Event Service that is designed to meet these requirements. This paper makes three contributions to the design and performance measurement of object-oriented real-time systems. First, it illustrates how to extend the CORBA Event Service so that it is suitable for real-time systems. These extensions support periodic …

Compositional Programming Abstractions For Mobile Computing, Peter J. Mccann, Gruia-Catalin Roman

All Computer Science and Engineering Research

Recent advances in wireless networking technology and the increasing demand for ubiquitous, mobile connectivity demonstrate the importance of providing reliable systems for managing reconfiguration and disconnection of components. Design of such systems requires tools and techniques appropriate to the task. Many formal models of computation, including UNITY, are not adequate for expressing reconfiguration and disconnection and are therefore inappropriate vehicles for investigating the impact of mobility on the construction of modular and composable systems. Algebraic formalisms such as the pi-calculus have been proposed for modeling mobility. This paper addresses the question of whether UNITY, a state-based formalism with a foundation …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 1, January 1997, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Multiprocessor Out-Of-Core Ffts With Distributed Memory And Parallel Disks, Thomas H. Cormen, Jake Wegmann, David M. Nicol

Computer Science Technical Reports

This paper extends an earlier out-of-core Fast Fourier Transform (FFT) method for a uniprocessor with the Parallel Disk Model (PDM) to use multiple processors. Four out-of-core multiprocessor methods are examined. Operationally, these methods differ in the size of "mini-butterfly" computed in memory and how the data are organized on the disks and in the distributed memory of the multiprocessor. The methods also perform differing amounts of I/O and communication. Two of them have the remarkable property that even though they are computing the FFT on a multiprocessor, all interprocessor communication occurs outside the mini-butterfly computations. Performance results on a small …

Development And Evaluation Of Interactive Courseware For Visualization Of Graph Data Structure And Algorithms, Thomas E. Beutel

CCAC Theses and Dissertations

The primary goal of this dissertation was to develop and pilot test interactive, multimedia courseware which would facilitate learning the abstract structures, operations, and concepts associated with graph and network data structures in Computer Science. Learning objectives and prerequisites are presented in an introduction section of the courseware and a variety of learning activities are provided including tutorials, animated demonstrations, interactive laboratory sessions, and self-tests. Courseware development incorporated principles and practices from software engineering, instructional design, and cognitive learning theories. Implementation utilized an easy-to-use authoring tool, NeoBook Professional (1994), to create the overall framework and the user interfaces, and Microsoft …

A Proposed Solution For Word-Recognition Deficit In The Computer Environment, Hyacinth Williams

CCAC Theses and Dissertations

Most college students with reading disabilities have difficulty with word recognition. The purpose of this study was to use an investigator-made cue word list to increase low word recognition skills among college students while creating slides for a university curriculum using a simple presentation tool. The investigator randomly divided fourteen subjects into two groups. One group received the treatment and the other did not. Subjects received fifty minutes to complete a five-slide presentation. The investigator used four different data collection processes for data collection. Beyond this, the investigator presented the results using rank correlation. Results from this study indicated that …

Random Number Generators For Parallel Computers, Paul D. Coddington

Northeast Parallel Architecture Center

Random number generators are used in many applications, from slot machines to simulations of nuclear reactors. For many computational science applications, such as Monte Carlo simulation, it is crucial that the generators have good randomness properties. This is particularly true for large-scale simulations done on high-performance parallel computers. Good random number generators are hard to find, and many widely-used techniques have been shown to be inadequate. Finding high-quality, efficient algorithms for random number generation on parallel computers is even more difficult. Here we present a review of the most commonly-used random number generators for parallel computers, and evaluate each generator …

Java For Parallel Computing And As A General Language For Scientific And Engineering Simulation And Modeling, Geoffrey C. Fox, Wojtek Furmanski

Northeast Parallel Architecture Center

We discuss the role of Java and Web technologies for general simulation. We classify the classes of concurrency typical in problems and analyze separately the role of Java in user interfaces, coarse grain software integration, and detailed computational kernels. We conclude that Java could become a major language for computational science, as it potentially offers good performance, excellent user interfaces, and the advantages of object-oriented structure.

Pcrc-Based Hpf Compilation, Guansong Zhang, Bryan Carpenter, Geoffrey C. Fox, Xiaoming Li

Northeast Parallel Architecture Center

This paper describes an ongoing effort supported by ARPA PCRC (Parallel Compiler Runtime Consortium) project. In particular, we discuss the design and implementation of an HPF compilation system based on PCRC runtime. The approaches to issues such as directive analysis and communication detection are discussed in detail. The discussion includes fragments of code generated by the compiler.

A Comparison Of Optimization Heuristics For The Data Mapping Problem, Nikos Chrisochoides, Nashat Mansour, Geoffrey C. Fox

Northeast Parallel Architecture Center

In this paper we compare the performance of six heuristics with suboptimal solutions for the data distribution of two dimensional meshes that are used for the numerical solution of Partial Differential Equations (PDEs) on multicomputers. The data mapping heuristics are evaluated with respect to seven criteria covering load balancing, interprocessor communication, flexibility and ease of use for a class of single-phase iterative PDE solvers. Our evaluation suggests that the simple and fast block distribution heuristic can be as effective as the other five complex and computational expensive algorithms.

Evaluation Of High Performance Fortran Through Application Kernels, Hon W. Yau, Geoffrey C. Fox, Ken Hawick

Northeast Parallel Architecture Center

Since the definition of the High Performance Fortran (HPF) standard, we have been maintaining a suite of application kernel codes with the aim of using them to evaluate the available compilers. This paper presents the results and conclusions from this study, for sixteen codes, on compilers from IBM, DEC, and the Portland Group Inc. (PGI), and on three machines: a DEC Alphafarm, an IBM SP-2, and a Cray T3D. From this, we hope to show the prospective HPF user that scalable performance is possible with modest effort, yet also where the current weaknesses lay.

Tango - A Collaborative Environment For The World-Wide Web, Lukasz Michal Beca, Gang Cheng, Geoffrey C. Fox, Tomasz Jurga, Konrad Olszewski, Marek Podgorny, Piotr Sokolowski, Tomasz Stachowiak, Krzysztof Walczak

Northeast Parallel Architecture Center

Geographical and logical growth of the World-Wide Web is accompanied by a fast technological development. Web can be successfully used as a platform for implementation of diverse applications. Distributed and collaborative systems are among the most challenging Web applications. TANGO is an integration platform which enables implementation of Web-based collaborative environments. The system provides means for fast integration of Web- and non-Web-applications into one multi-user collaborative systems. In this paper we describe the functional model, requirements, system design and certain implementation issues of the TANGO system.

Expert System For The Generation Of A Work Breakdown Structure, Bernard O'Callaghan

Theses

This thesis outlines research work carried out in the Mechanical & Manufacturing Department in Cork Regional Technical College, Ireland. With computers now having an increasingly dominant role in all areas of business, it was inevitable that computer-based project management packages would become more popular. To date however, these packages have concentrated on monitoring and controlling projects. The definition and brainstorming phases required to generate a project plan are still largely manual tasks. Planning a project initially involves generating a complete and organised list of all the tasks needing to be completed in order to achieve a project’s goal. This list …