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Articles 55021 - 55050 of 58034

Full-Text Articles in Physical Sciences and Mathematics

Distributed Multimedia Systems Research Prospectus, Jonathan Turner Jan 1994

Distributed Multimedia Systems Research Prospectus, Jonathan Turner

All Computer Science and Engineering Research

Distributed multimedia computing and communiation systems combine computer systems, networks and distributed software to facilitate applications that enable and enhance collaborative work, direct interpersonal communication, remote access to information and real-time presentation of information from a variety of sources. Over the next decade, we expect such systems to become central to the infrastructure of our increasingly information-driven society. This prospectus describes a program of research being pursued within the Computer and Communications Research Center of Washington University and the Departments of Computer Science and Electrical Engineering. This program seeks to promote the creation of effective distributed multimedia systems and develop …

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Proposal For Research Distribution Of Gigabit Network Technology, Jonathan Turner Jan 1994

Proposal For Research Distribution Of Gigabit Network Technology, Jonathan Turner

All Computer Science and Engineering Research

In 1993, APRA funded a major program at Washingotn University to create gigabit networking technology and create a gigabit testbed based on this technology. This program is now nearing the end of its first year and is making excellent proress towards its research and technical objectives. This note a proposes a program that would lead to the export of this technology to research groups in networking and gigabit applications with an interest in using it to further their own research activities.

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Design Of An Application Development Toolkit For Hpf/Fortran 90d, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox Jan 1994

Design Of An Application Development Toolkit For Hpf/Fortran 90d, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox

Northeast Parallel Architecture Center

The development of efficient application software capable of exploiting available High Performance Computing (HPC) systems is non-trivial and is largely governed by the availability of sufficiently high-level languages, tools, and application development environments. In this paper we describe the design and operation of a toolkit for HPF/Fortran 90D application development. The toolkit incorporates the following systems: (1) ESP: An Interpretive Framework for HPF/Fortran 90D Performance Prediction; (2) ESP-i: A HPF/Fortran 90D Functional Interpreter; and (3) ESPial: An Integrated Environment for HPF/Fortran 90D Application Development & Execution. The toolkit has been implemented on the iPSC/860 hypercube system, and is supported by …

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Supporting Irregular Distributions In Fortran 90d/Hpf Compilers, Ravi Ponnusamy, Yuan-Shin Hwang, Raja Das, Joel Saltz Jan 1994

Supporting Irregular Distributions In Fortran 90d/Hpf Compilers, Ravi Ponnusamy, Yuan-Shin Hwang, Raja Das, Joel Saltz

Northeast Parallel Architecture Center

This paper presents methods that make it possible to efficiently support irregular problems using data parallel languages. The approach involves the use of a portable, compiler-independent, runtime support library called CHAOS. The CHAOS runtime support library contains procedures that (1) support static and dynamic distributed array partitioning, (2) partition loop iterations and indirection arrays, (3) remap arrays from one distribution to another, and (4) carry out index translation, buffer allocation and communication schedule generation. The CHAOS runtime procedures are used by a prototype Fortran 90D compiler as runtime support for irregular problems. This paper also presents performance results of compiler-generated …

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Mapping Algorithms And Software Environment For Data Parallel, Nikos Chrisochoides, Elias Houstis, John Rice Jan 1994

Mapping Algorithms And Software Environment For Data Parallel, Nikos Chrisochoides, Elias Houstis, John Rice

Northeast Parallel Architecture Center

We consider computations associated with data parallel iterative solvers used for the numerical solution of Partial Differential Equations (PDEs). The mapping of such computations into load balanced tasks requiring minimum synchronization and communication is a difficult combinatorial optimization problem. Its optimal solution is essential for the efficient parallel processing of PDE computations. Determining data mappings that optimize a number of criteria, like workload balance, synchronization and local communication, often involves the solution of an NP-Complete problem. Although data mapping algorithms have been known for a few years there is lack of qualitative and quantitative comparisons based on the actual performance …

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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 …

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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.

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Compiling Fortran 90d/Hpf For Distributed Memory Mimd Computers, Zeki Bozkus, Alok Choudhary, Geoffrey C. Fox, Tomasz Haupt Jan 1994

Compiling Fortran 90d/Hpf For Distributed Memory Mimd Computers, Zeki Bozkus, Alok Choudhary, Geoffrey C. Fox, Tomasz Haupt

Northeast Parallel Architecture Center

This paper describes the design of the Fortran90D/HPF compiler, a source-to-source parallel compiler for distributed memory systems being developed at Syracuse University. Fortran 90D/HPF is a data parallel language with special directives to specify data alignment and distributions. A systematic methodology to process distribution directives of Fortran 90D/HPF is presented. Furthermore, techniques for data and computation partitioning, communication detection and generation, and the run-time support for the compiler are discussed. Finally, initial performance results for the compiler are presented. We believe that the methodology to process data distribution, computation partitioning, communication system design and the overall compiler design can be …

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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 …

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Run-Time And Compile-Time Support For Adaptive Irregular Problems, Shamik D. Sharma, Ravi Ponnusamy, Bongki Moon, Yuan-Shin Hwang Jan 1994

Run-Time And Compile-Time Support For Adaptive Irregular Problems, Shamik D. Sharma, Ravi Ponnusamy, Bongki Moon, Yuan-Shin Hwang

Northeast Parallel Architecture Center

In adaptive irregular problems the data arrays are accessed via indirection arrays, and data access patterns change during computation. Implementing such problems on distributed memory machines requires support for dynamic data partitioning, efficient preprocessing and fast data migration. This research presents efficient runtime primitives for such problems. This new set of primitives is part of the CHAOS library. It subsumes the previous PARTI library which targeted only static irregular problems. To demonstrate the efficacy of the runtime support, two real adaptive irregular applications have been parallelized using CHAOS primitives: a molecular dynamics code (CHARMM) and a particle-in-cell code (DSMC). The …

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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 …

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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.

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Design Issues For The Parallelization Of An Optimal Interpolation Algorithm, Gregor Von Laszewski, Mike Seablom, Miloje Makivic, Peter Lyster Jan 1994

Design Issues For The Parallelization Of An Optimal Interpolation Algorithm, Gregor Von Laszewski, Mike Seablom, Miloje Makivic, Peter Lyster

Northeast Parallel Architecture Center

A regionalized optimal interpolation algorithm is currently used at the NASA Goddard Data Assimilation Office (DAO) for four dimensional data assimilation. Instead of using all observations regions are defined to approximate the solution. The sequential code for the regionalized optimal interpolation is very complex and in its current form unusable for MIMD machines. This paper describes the efforts at the DAO to parallelize the existing sequential algorithm. We outline three strategies transforming the sequential algorithm gradually to MIMD machines. A major requirement for the new parallel algorithm is the portability to as many MIMD machines as possible. Therefore, the parallel …

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Runtime Array Redistribution In Hpf Programs, Rajeev Thakur, Alok Choudhary, Geoffrey C. Fox Jan 1994

Runtime Array Redistribution In Hpf Programs, Rajeev Thakur, Alok Choudhary, Geoffrey C. Fox

Northeast Parallel Architecture Center

This paper describes efficient algorithms for runtime array redistribution in HPF programs. We consider block(m) to cyclic, cyclic to block(m) and the general cyclic(x) to cyclic(y) type redistributions. We initially describe algorithms for one-dimensional arrays and then extend the methodology to multidimensional arrays. The algorithms are practical enough to be easily implemented in the runtime library of an HPF compiler and can also be directly used in application programs requiring redistribution. Performance results on the Intel Paragon are discussed.

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A Generalized Expression Optimization Hook For C++ On High-Performance Architectures, David J. Edelsohn Jan 1994

A Generalized Expression Optimization Hook For C++ On High-Performance Architectures, David J. Edelsohn

Northeast Parallel Architecture Center

C++ has gained broad acceptance as an object-oriented evolutionary extension to the C language, but it severely constrains methods for operating on class objects by forcing all data manipulation through an interface which assumes that all basic operations can be implemented as they are written: as unary or binary operators. C++ allows great flexibility in the creation of complex data structures which can perform the same functionality as built-in types of many other languages, but unfortunately it does not allow an equivalent level of flexibility so that operators acting on those data types can achieve the same level of efficiency …

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Analysis Of Random Number Generators Using Monte Carlo Simulation, Paul D. Coddington Jan 1994

Analysis Of Random Number Generators Using Monte Carlo Simulation, Paul D. Coddington

Northeast Parallel Architecture Center

Monte Carlo simulation is one of the main applications involving the use of random number generators. It is also one of the best methods of testing the randomness properties of such generators, by comparing results of simulations using different generators with each other, or with analytic results. Here we compare the performance of some popular random number generators by high precision Monte Carlo simulation of the 2-d Ising model, for which exact results are known, using the Metropolis, Swendsen-Wang, and Wolff Monte Carlo algorithms. Many widely used generators that perform well in standard statistical tests are shown to fail these …

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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 …

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Interpreting The Performance Of Hpf/Fortran 90d, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox Jan 1994

Interpreting The Performance Of Hpf/Fortran 90d, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox

Northeast Parallel Architecture Center

In this paper we present a novel interpretive approach for accurate and cost-effective performance prediction in a high performance computing environment, and describe the design of a source-driven HPF/Fortran 90D performance prediction framework based on this approach. The performance prediction framework has been implemented as part of a HPF/Fortran 90D application development environment. A set of benchmarking kernels and application codes are used to validate the accuracy, utility, usability, and cost-effectiveness of the performance prediction framework. The use of the framework for selecting appropriate compiler directives and for application performance debugging is demonstrated. Keywords: Performance prediction, HPF/Fortran 90D application development, …

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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 …

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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.

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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 …

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Is Oberon As Simple As Possible?, Atanas Radenski Jan 1994

Is Oberon As Simple As Possible?, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Books and Book Chapters

The design of the programming language Oberon was led by the quote by Albert Einstein: 'make it as simple as possible, but not simpler'. The objective of this paper is to analyze some design solutions and propose alternatives which could both simplify and strengthen the language without making it simpler than possible. The paper introduces one general concept, the module type, which can be used to represent records, modules, and eventually procedures. Type extension is redefined in terms of component nesting and incomplete designators. As a result, type extension supports multiple inheritance.

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Evolution In The Microprocessor Industry For Personal Computers: The Shift From Cisc Chips To Risc Chips, James Lamm Jan 1994

Evolution In The Microprocessor Industry For Personal Computers: The Shift From Cisc Chips To Risc Chips, James Lamm

Honors Theses, 1963-2015

The thesis examines the semiconductor industry, specifically focusing on microprocessor manufacturers for the personal computer market. The current technology in the industry, CISC microprocessors, have reached a price/performance limit. The industry is turning to RISC microprocessors for improved speed at lower costs. Intel, the current industry leader, is being challenged by AMD and Cyrix, who manufacture clones of Intel¹s microprocessors. In addition, Motorola, another giant in the industry, has teamed up with Apple and IBM to challenge Intel¹s dominance of the industry. Motorola is attempting to set a new microprocessor standard based on a RISC microprocessor, the Power PC. Intel …

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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 …

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Measurement Of Cabibbo-Suppressed Decays Of The Τ Lepton, Battle, M.; Et Al., M. Thulasidas Jan 1994

Measurement Of Cabibbo-Suppressed Decays Of The Τ Lepton, Battle, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

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On The Equivalence Of Mceliece's And Niederreiter's Public-Key Cryptosystems, Y. X. Li, Robert H. Deng, X. M. Wang Jan 1994

On The Equivalence Of Mceliece's And Niederreiter's Public-Key Cryptosystems, Y. X. Li, Robert H. Deng, X. M. Wang

Research Collection School Of Computing and Information Systems

It is shown that McEliece's and Niederreiter's public-key cryptosystems are equivalent when set up for corresponding choices of parameters. A security analysis for the two systems based on this equivalence observation, is presented

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Exclusive Hadronic B Decays To Charm And Charmonium Final States, Alam, M.; Et Al., M. Thulasidas Jan 1994

Exclusive Hadronic B Decays To Charm And Charmonium Final States, Alam, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We have fully reconstructed decays of both B¯0 and B− mesons into final states containing either D, D*, D**, ψ, ψ’, or χc1 mesons. This allows us to obtain new results on many physics topics including branching ratios, tests of the factorization hypothesis, color suppression, resonant substructure, and the B−−B¯0 mass difference.

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Financial Aid Budget Projection Methodology, Amy N. Baird '94 Jan 1994

Financial Aid Budget Projection Methodology, Amy N. Baird '94

Honors Projects

The nature of this research project is to make a very strong contribution toward the final goal of completely automating the Financial Aid Office at Illinois Wesleyan University over the next five years.

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Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 1, January 1994, College Of Engineering And Computer Science, Wright State University Jan 1994

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 1, January 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

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Compilation Techniques For Irregular Problems On Parallel Machines, Subhendu Das Jan 1994

Compilation Techniques For Irregular Problems On Parallel Machines, Subhendu Das

Dissertations, Theses, and Masters Projects

Massively parallel computers have ushered in the era of teraflop computing. Even though large and powerful machines are being built, they are used by only a fraction of the computing community. The fundamental reason for this situation is that parallel machines are difficult to program. Development of compilers that automatically parallelize programs will greatly increase the use of these machines.;A large class of scientific problems can be categorized as irregular computations. In this class of computation, the data access patterns are known only at runtime, creating significant difficulties for a parallelizing compiler to generate efficient parallel codes. Some compilers with …

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