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 60781 - 60810 of 63852

Full-Text Articles in Entire DC Network

The Design And Evolution Of Zipcode, Anthony Skjellum, Steven G. Smith, Nathan E. Doss, Alvin Leung Jan 1994

The Design And Evolution Of Zipcode, Anthony Skjellum, Steven G. Smith, Nathan E. Doss, Alvin Leung

Northeast Parallel Architecture Center

Zipcode is a message-passing and process-management system that was designed for multicomputers and homogeneous networks of computers in order to support libraries and large-scale multicomputer software. The system has evolved significantly over the last five years, based on our experiences and identified needs. Features of Zipcode that were originally unique to it, were its simultaneous support of static process groups, communication contexts, and virtual topologies, forming the "mailer" data structure. Point-to-point and collective operations reference the underlying group, and use contexts to avoid mixing up messages. Recently, we have added "gather-send" and "receive-scatter" semantics, based on persistent Zipcode "invoices," both …


A Communication System For High-Performance Distributed Computing, Salim Hariri, Jongbaek Park, Manish Parashar, Geoffrey C. Fox Jan 1994

A Communication System For High-Performance Distributed Computing, Salim Hariri, Jongbaek Park, Manish Parashar, Geoffrey C. Fox

Northeast Parallel Architecture Center

With the current advances in computer and networking technology coupled with the availability of software tools for parallel and distributed computing, there has been increased interests in high-performance distributed computing (HPDC). We envision that HPDC environments with supercomputing capabilities will be available in the near future. However, a number of issues have to be resolved before future network-based applications can exploit fully the potential of HPDC environment. In this paper, we present an architecture of a high-speed local area network and a communication system that provides HPDC applications with high bandwidth and low latency. We also characterize the message-passing primitives …


Developing Interactive Pvm-Based Parallel Programs On Distributed Computing Systems Within Avs Framework, Gang Cheng, Geoffrey C. Fox, Kim Mills, Marek Podgorny Jan 1994

Developing Interactive Pvm-Based Parallel Programs On Distributed Computing Systems Within Avs Framework, Gang Cheng, Geoffrey C. Fox, Kim Mills, Marek Podgorny

Northeast Parallel Architecture Center

We discuss techniques in developing interactive Parallel Virtual Machine (PVM) concurrent programs on distributed systems under AVS framework. Using a stock option price modeling application as a case study, we demonstrate a simple, effective and modular approach to coupling network-based concurrent modules into an interactive remote visualization environment. A prototype simulation on-demand system is developed, in which parallel option pricing models locally implemented on two distributed systems, an Ethernet-connected IBM SP1 and a FDDI-based GIGswitch-connected DEC Alpha farm, are coupled with an interactive graphical user interface over a ATM-based wide area network. This integrated networking/visualization framework allows one to use …


Involvement Of Industry In The National High Performance Computing And Communication Enterprise, Geoffrey C. Fox Jan 1994

Involvement Of Industry In The National High Performance Computing And Communication Enterprise, Geoffrey C. Fox

Northeast Parallel Architecture Center

We discuss aspects of a national computer science agenda for High Performance Computing and Communications (HPCC). We agree with the general direction and emphasis of the current program. In particular, the strong experimental component and linkage of applications with computer science should be continued. We recommend accelerating the emphasis on "national challenges " with more applications and technologies from the information, as compared to simulation areas. We suggest modifying the grand challenge concept to complement the current teaming of particular computer science and applications researchers. We would emphasize better linking of each application group to the entire (inter) national computer …


A Study Of Software Development For High Performance Computing, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox Jan 1994

A Study Of Software Development For High Performance Computing, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox

Northeast Parallel Architecture Center

Software development in a High Performance Computing (HPC) environment is non-trivial and requires a thorough understanding of the application and the architecture. The objective of this paper is to study the software development process in a high performance computing environment and to outline the stages typically encountered in this process. Support required at each stage is also highlighted. The modeling of stock option pricing is used as a running example in the study.


Developing Modular Application Builders To Exploit Mimd Parallel Resources, C. Thornborrow, C. Faigle Jan 1994

Developing Modular Application Builders To Exploit Mimd Parallel Resources, C. Thornborrow, C. Faigle

Northeast Parallel Architecture Center

Modular application builders (MABs), such as AVS and Iris Explorer[6, 7] are increasingly being used in the visualisation community. Such systems can already place compute intensive modules on supercomputers in order to utilise their power. This paper details two major projects at EPCC which attempted to fully integrate the MAB concept with a distributed memory MIMD (DM-MIMD) environment. The work presented was driven by two goals, efficient use of the resource and ease of use by programmer and end user. We present a model of MABs and describe the major problems faced, giving solutions to them through two case studies.


Applications And Enabling Technology For Nynet Upstate Corridor, Salim Hariri, Geoffrey C. Fox Jan 1994

Applications And Enabling Technology For Nynet Upstate Corridor, Salim Hariri, Geoffrey C. Fox

Northeast Parallel Architecture Center

Current advances in telecommunication and computing will have significant impact on the proliferation of high performance computing and communication (HPCC) applications. With these emerging technologies, it is feasible to run parallel and distributed applications across a high speed wide area network which was not possible a few years ago; the high latency and low bandwidth were the main bottlenecks for the wide area network-based computing. This has lead to the deployment of several high speed networks across the country (eg. NYNET). In this report, we describe some of the HPCC applications and our experiences and lessons learned from running them …


The Virtual Computing Environment, Philip Rousselle, Paul Tymann, Salim Hariri, Geoffrey C. Fox Jan 1994

The Virtual Computing Environment, Philip Rousselle, Paul Tymann, Salim Hariri, Geoffrey C. Fox

Northeast Parallel Architecture Center

A network of supercomputers and high-performance workstations appears to be the only reasonable way to provide adequate computing resources for the Grand Challenge problems of the next century. Such a collection of computers and supporting software environments is called a virtual computing environment (VCE). This paper describes the motivation and goals of the VCE project, followed by a description of the system. The paper concentrates on the runtime aspects of the VCE, and concludes with a discussion of a small prototype system that has been built using the Isis distributed toolkit.


Data Access Reorganizations In Compiling Out-Of-Core Data Parallel Programs On Distributed Memory Machines, Rajesh Bordawekar, Alok Choudhary, Rajeev Thakur Jan 1994

Data Access Reorganizations In Compiling Out-Of-Core Data Parallel Programs On Distributed Memory Machines, Rajesh Bordawekar, Alok Choudhary, Rajeev Thakur

Electrical Engineering and Computer Science - All Scholarship

This paper describes techniques for translating out-of-core programs written in a data parallel language like HPF to message passing node programs with explicit parallel I/O. We describe the basic compilation model and various steps involved in the compilation. The compilation process is explained with the help of an out-of-core matrix multiplication program. We first discuss how an out-of-core program can be translated by extending the method used for translating in-core programs. We demonstrate that straightforward extension of in-core compiler does not work for out-of-core programs. We then describe how the compiler can optimize the code by (1) estimating the I/O …


Passion: Parallel And Scalable Software For Input-Output, Alok Choudhary, Rajesh Bordawekar, Michael Harry, Rakesh Krishnaiyer Jan 1994

Passion: Parallel And Scalable Software For Input-Output, Alok Choudhary, Rajesh Bordawekar, Michael Harry, Rakesh Krishnaiyer

Electrical Engineering and Computer Science - All Scholarship

We are developing a software system called PASSION: Parallel And Scalable Software for Input-Output which provides software support for high performance parallel I/O. PASSION provides support at the language, compiler, runtime as well as file system level. PASSION provides runtime procedures for parallel access to files (read/write), as well as for out-of-core computations. These routines can either be used together with a compiler to translate out-of-core data parallel programs written in a language like HPF, or used directly by application programmers. A number of optimizations such as Two-Phase Access, Data Sieving, Data Prefetching and Data Reuse have been incorporated in …


Determination Of Budgetary Expertise Among Public School Library Media Specialists In The State Of Florida, Mary Hosken Jan 1994

Determination Of Budgetary Expertise Among Public School Library Media Specialists In The State Of Florida, Mary Hosken

CCAC Theses and Dissertations

In 1988, Information Power described skills and duties expected of a school library media specialist. These include familiarity with various forms of educational technology, interpersonal social and communication skills, and proficiency in a wide range of planning and management areas. Simultaneously, restructuring, a movement to site-based management, requires new types of skills of Florida's teachers.

While the importance and complexity of the position of library media specialist has increased, there is concern that some practicing professionals do not have training or experience to address these new obligations. As a benchmark of current expertise in non-instructional duties, this research effort attempted …


The Electronic Bulletin Board As A Means Of Professional Communication Among Physics Teachers, Donald L. Mcgarry Jan 1994

The Electronic Bulletin Board As A Means Of Professional Communication Among Physics Teachers, Donald L. Mcgarry

CCAC Theses and Dissertations

Teachers of secondary school physics are often physically isolated from their peers; that is, they do not have as much contact with their physics colleagues as they desire. One reason for this physical isolation is the relatively small population of students enrolled in high school physics courses resulting in small numbers of physics teachers per school. Another is that many physics teachers are teaching physics only part time.

One method of communication among teachers has the potential to improve professional communication among physics teachers. This is the computer operated electronic bulletin board system (BBS). Bulletin board systems and variants have …


Relationship Between Information System Project Characteristics And Project Management Activities: An Empirical Investigation, Vijay V. Raghavan, Deepak Khazanchi, Joyce L. Webster Jan 1994

Relationship Between Information System Project Characteristics And Project Management Activities: An Empirical Investigation, Vijay V. Raghavan, Deepak Khazanchi, Joyce L. Webster

Information Systems and Quantitative Analysis Faculty Publications

The activities of a project manager in overseeing the development of a software system are many and varied. Not all such activities are performed in managing every project. If so, a natural ensuing question is whether project managers adapt their managerial functions to the projects being managed. Prior research suggests that they do adapt, and that project characteristics may be the factors determining this adaptation. This assertion is investigated by considering three characteristics of a project (size, type, and environment) and investigating their association with four traditionally recognized management functions (planning, organizing, controlling, and motivating). Results indicate that project managers …


An ‘Events’ Model For Information Aggregation, Douglas Havelka, Deepak Khazanchi Jan 1994

An ‘Events’ Model For Information Aggregation, Douglas Havelka, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Aggregation is one of the key characteristics of information delivered by "information systems." It is important because the ability to design effective support systems depends to a great extent upon the degree of flexibility with regards to information aggregation that can be incorporated in the system. This paper sets forth a conceptual model of information aggregation based on the events theory of accounting. The model suggests that aggregation should be considered as a two-dimensional concept, comprising a temporal and sectional dimension. The two axes are further delineated in the form of "levels of summation" based on specified "events" of aggregation. …


The Management Of Information Technology Investments In The Australian Ambulance Services, Anthony J. Ahern Jan 1994

The Management Of Information Technology Investments In The Australian Ambulance Services, Anthony J. Ahern

Theses: Doctorates and Masters

Information Technology plays a significant role in the administration and operation of most organisations today. This is certainly the case with each of the Australian Ambulance Services. With the rapid increase in the use of Information Technology and the expectation about its use by both staff and the general public, the Ambulance Service managements' are faced with the dilemma of trying to ensure that their organisations are able to get the full advantage of advances in Information Technology and at the same time ensure that investments in IT are maintained at appropriate levels that will ensure the maximum return on …


Applications Of Fuzzy Counterpropagation Neural Networks To Non-Linear Function Approximation And Background Noise Elimination, I. M. Wiryana Jan 1994

Applications Of Fuzzy Counterpropagation Neural Networks To Non-Linear Function Approximation And Background Noise Elimination, I. M. Wiryana

Theses: Doctorates and Masters

An adaptive filter which can operate in an unknown environment by performing a learning mechanism that is suitable for the speech enhancement process. This research develops a novel ANN model which incorporates the fuzzy set approach and which can perform a non-linear function approximation. The model is used as the basic structure of an adaptive filter. The learning capability of ANN is expected to be able to reduce the development time and cost of the designing adaptive filters based on fuzzy set approach. A combination of both techniques may result in a learnable system that can tackle the vagueness problem …


A Model Of Visual Recognition Implemented Using Neural Networks, Vincent C. Phillips Jan 1994

A Model Of Visual Recognition Implemented Using Neural Networks, Vincent C. Phillips

Theses: Doctorates and Masters

The ability to recognise and classify objects in the environment is an important property of biological vision. It is highly desirable that artificial vision systems also have this ability. This thesis documents research into the use of artificial neural networks to implement a prototype model of visual object recognition. The prototype model, describing a computtional architecture, is derived from relevant physiological and psychological data, and attempts to resolve the use of structural decomposition and invariant feature detection. To validate the research a partial implementation of the model has been constructed using multiple neural networks. A linear feed-forward network performs pre-procesing …


Vic*: A Preprocessor For Virtual-Memory C*, Thomas H. Cormen, Alex Colvin Jan 1994

Vic*: A Preprocessor For Virtual-Memory C*, Thomas H. Cormen, Alex Colvin

Computer Science Technical Reports

This paper describes the functionality of ViC*, a compiler-like preprocessor for out-of-core C*. The input to ViC* is a C* program but with certain shapes declared \verb`outofcore`, which means that all parallel variables of these shapes reside on disk. The output is a standard C* program with the appropriate I/O and library calls added for efficient access to out-of-core parallel variables.


Introducing Objects And Parallelism To An Imperative Programming Language, Atanas Radenski Jan 1994

Introducing Objects And Parallelism To An Imperative Programming Language, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

The problem of enhancing objects with parallelism has been in the focus of numerous research projects in the recent years, but a satisfactory and commonly accepted solution has not appeared yet. A major problematic point seems to be providing inheritance for parallel objects. The general objective of this paper is to contribute to a better understanding of the language design issues in the area of parallel object-oriented programming (OOP) and, in particular, to design a framework for parallel OOP with multiple inheritance. What makes our proposed framework different from the other parallel OOP languages is its easy to use and …


Visualizing Electrostatic Phenomena Using Mathematica, Eric Mayes Jan 1994

Visualizing Electrostatic Phenomena Using Mathematica, Eric Mayes

Journal of the Arkansas Academy of Science

A set of packages for visualizing electrostatic phenomena was developed using Mathematica as a programming language. These packages allow users to plot potential fields, equipotential lines, 2-D and 3-D vector fields in order to gain a visual understanding of electrostatic charges. They would be useful in accompanying undergraduate physics labs pertaining to electrostatics, as they would enable students to connect experiment with mathematics through open-ended visual exploration


Neural Network Diagnosis Of Malignant Melanoma From Color Images, Fikret Erçal, Hsi-Chieh Lee, William V. Stoecker, Randy Hays Moss, Anurag Chawla Jan 1994

Neural Network Diagnosis Of Malignant Melanoma From Color Images, Fikret Erçal, Hsi-Chieh Lee, William V. Stoecker, Randy Hays Moss, Anurag Chawla

Computer Science Faculty Research & Creative Works

Malignant melanoma is the deadliest form of all skin cancers. Approximately 32,000 new cases of malignant melanoma were diagnosed in 1991 in the United States, with approximately 80% of patients expected to survive 5 years. Fortunately, if detected early, even malignant melanoma may be treated successfully, Thus, in recent years, there has been rising interest in the automated detection and diagnosis of skin cancer, particularly malignant melanoma. Here, the authors present a novel neural network approach for the automated separation of melanoma from 3 benign categories of tumors which exhibit melanoma-like characteristics. The approach uses discriminant features, based on tumor …


Resolving Attribute Incompatibility In Database Integration: An Evidential Reasoning Approach, Ee-Peng Lim, Shashi Shekhar Jan 1994

Resolving Attribute Incompatibility In Database Integration: An Evidential Reasoning Approach, Ee-Peng Lim, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel (1989) showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. The authors show that uncertain information can also arise when the database integration process requires information not directly represented in the component databases, but can be obtained through some summary of data. They therefore propose an extended relational model based on Dempster-Shafer theory of evidence (1976) to incorporate such uncertain knowledge about the source databases. They also develop a full set of extended relational operations …


Merlin's Magic Square Enhanced, Gary R. Greenfield Jan 1994

Merlin's Magic Square Enhanced, Gary R. Greenfield

Department of Math & Statistics Technical Report Series

This paper first considers questions about games related to Merlin's Magic Square from the point of view of group actions. At this juncture, little beyond the formal model is new, but the exposition sets the stage for considering certain "enhanced" versions of these games. The analysis of enhanced games, with the aid of semigroup actions, is carried out in complete detail for an ostensibly simpler (k = 3) game before turning to a Merlin ( k = 4) game. Concluding sections discuss various ways to generalize our games.

To review the solution to Merlin's Magic Square, we begin by introducing …


Issues And Obstacles With Multimedia Authoring, Fillia Makedon, Samuel A. Rebelsky, Matthew Cheyney, Charles Owen, Peter Gloor Jan 1994

Issues And Obstacles With Multimedia Authoring, Fillia Makedon, Samuel A. Rebelsky, Matthew Cheyney, Charles Owen, Peter Gloor

Dartmouth Scholarship

Unlike traditional authoring, multimedia authoring involves making hard choices, forecasting technological evolution and adapting to software and hardware technology changes. It is, perhaps, an unstable field of endeavor for an academic to be in. Yet, it is important that academics are, in fact, part of this process. This paper discusses some of the common threads shared by three dissimilar cases of multimedia authoring which we have experimented with, that of multimedia conference proceedings, multimedia courseware development and multimedia information kiosks. We consider these applications from an academic point of view and review the benefits and pitfalls of academic development while …


Generalized Ffts - A Survey Of Some Recent Results, David K. Maslen, Daniel N. Rockmore Jan 1994

Generalized Ffts - A Survey Of Some Recent Results, David K. Maslen, Daniel N. Rockmore

Dartmouth Scholarship

In this paper we survey some recent work directed towards generalizing the fast Fourier transform (FFT). We work primarily from the point of view of group representation theory. In this setting the classical FFT can be viewed as a family of efficient algorithms for computing the Fourier transform of either a function defined on a finite abelian group, or a bandlimited function on a compact abelian group. We discuss generalizations of the FFT to arbitrary finite groups and compact Lie groups.


Disk-Directed I/O For Mimd Multiprocessors, David Kotz Jan 1994

Disk-Directed I/O For Mimd Multiprocessors, David Kotz

Dartmouth Scholarship

Many scientific applications that run on today's multiprocessors are bottlenecked by their file I/O needs. Even if the multiprocessor is configured with sufficient I/O hardware, the file-system software often fails to provide the available bandwidth to the application. Although libraries and improved file-system interfaces can make a significant improvement, we believe that fundamental changes are needed in the file-server software. We propose a new technique, \em disk-directed I/O, that flips the usual relationship between server and client to allow the disks (actually, disk servers) to determine the flow of data for maximum performance. Our simulations show that tremendous performance gains …


Reconstruction Of Surfaces And Surfaces- On-Surfaces From Unorganized Weighted Points, Chandrajit L. Bajaj, Fausto Bernardini, Guoliang Xu Jan 1994

Reconstruction Of Surfaces And Surfaces- On-Surfaces From Unorganized Weighted Points, Chandrajit L. Bajaj, Fausto Bernardini, Guoliang Xu

Department of Computer Science Technical Reports

No abstract provided.


Edge Weight Reduction Problems In Directed, Acyclic Graphs, Susanne E. Hambrusch, Hung-Yi Tu Jan 1994

Edge Weight Reduction Problems In Directed, Acyclic Graphs, Susanne E. Hambrusch, Hung-Yi Tu

Department of Computer Science Technical Reports

No abstract provided.


Sbl- The Structural Biology Language, Marius A. Cornea-Hasegan, Dan C. Marinescu Jan 1994

Sbl- The Structural Biology Language, Marius A. Cornea-Hasegan, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.


Smooth Low Degree Approximations Of Polyhedra, Chandrajit L. Bajaj, Jindon Chen, Guoliang Xu Jan 1994

Smooth Low Degree Approximations Of Polyhedra, Chandrajit L. Bajaj, Jindon Chen, Guoliang Xu

Department of Computer Science Technical Reports

No abstract provided.