Digital Commons Network^™

A Compilation Approach For Fortran 90d/Hpf Compilers On Distributed Memory Mimd Computers, Zeki Bozkus, Alok Choudhary, Geoffrey C. Fox, Tomasz Haupt

Northeast Parallel Architecture Center

This paper describes a compilation approach for a Fortran 90D/HPF compiler, a source-to-source parallel compiler for distributed memory systems. Different from Fortran 77 parallelizing compilers, a Fortran90D/HPF compiler does not parallelize sequential constructs. Only parallelism expressed by Fortran 90D/HPF parallel constructs is exploited. The methodology of parallelizing Fortran programs such as computation partitioning, communication detection and generation, and the run-time support for the compiler are discussed. An example of Gaussian Elimination is used to illustrate the compilation techniques with performance results.

Integrating Multiple Programming Paradigms On Connection Machine Cm5 In A Dataflow-Based Software Environment, Gang Cheng, Geoffrey C. Fox, Kim Mills

Northeast Parallel Architecture Center

By viewing different parallel programming paradigms as essential heterogeneous approaches in mapping "real-world" problems to parallel systems, we discuss methodologies in integrating multiple programming models on a Connection Machine CM5. In a data flow based integration model built in a visualization software AVS, we demonstrate a simple, effective and modular way to couple sequential, data-parallel and explicit message-passing modules into an integrated programming environment on the CM5.

The Multicomputer Toolbox - First-Generation Scalable Libraries, Anthony Skjellum, Alvin Leung, Steven G. Smith, Robert D. Falgout

Northeast Parallel Architecture Center

"First-generation" scalable parallel libraries have been achieved, and are maturing, within the Multicomputer Toolbox. The Toolbox includes sparse, dense, iterative linear algebra, a stiff ODE/DAE solver, and an open software technology for additional numerical algorithms, plus an inter-architecture Makefile mechanism for building applications. We have devised C-based strategies for useful classes of distributed data structures, including distributed matrices and vectors. The underlying Zipcodemessage passing system has enabled process-grid abstractions of multicomputers, communication contexts, and process groups, all characteristics needed for building scalable libraries, and scalable application software. We describe the data-distribution-independent approach to building scalable libraries, which is needed so …

A Message Passing Interface For Parallel And Distributed Computing, Salim Hariri, Jongbaek Park, Fang-Kuo Yu, Manish Parashar

Northeast Parallel Architecture Center

The proliferation of high performance workstations and the emergence of high speed networks have attracted a lot of interest in parallel and distributed computing (PDC). We envision that PDC environments with supercomputing capabilities will be available in the near future. However, a number of hardware and software issues have to be resolved before the full potential of these PDC environments can be exploited. The presented research has the following objectives: (1) to characterize the message-passing primitives used in parallel and distributed computing; (2) to develop a communication protocol that supports PDC; and (3) to develop an architectural support for PDC …

Hierarchical Tree-Structures As Adaptive Meshes, David J. Edelsohn

Northeast Parallel Architecture Center

Introduction: Two basic types of simulations exist for modeling systems of many particles: grid-based (point particles indirectly interacting with one another through the potential calculated from equivalent particle densities on a mesh) and particle-based (point particles directly interacting with a one another through potentials at their positions calculated from the other particles in the system). Grid-based solvers traditionally model continuum problems, such as fluid and gas systems, and mixed particle-continuum systems. Particle-based solvers find more use modeling discrete systems such as stars within galaxies or other rarefied gases. Many different physical systems, including electromagnetic interactions, gravitational interactions, and fluid vortex …

An Interpretive Framework For Application Performance Prediction, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox

Northeast Parallel Architecture Center

Software development in parallel/distributed environment is a non-trivial task and depends greatly on the availability of appropriate support in terms of development tools and environments. Performance prediction /evaluation tools form a critical part of any software development environment as they enable the developer to visualize the effects of various design choices on the performance of the application. This paper presents an interpretive model for a source driven performance prediction framework. A prototype framework based on the proposed model has been developed for the iPSC/860 system. Numerical results obtained on this system are presented. These results confirm the potential of interpretive …

Complete Exchange On A Wormhole Routed Mesh, Rajeev Thakur, Alok Choudhary, Geoffrey C. Fox

Northeast Parallel Architecture Center

The complete exchange (or all-to-all personalized) communication pattern occurs frequently in many important parallel computing applications. We discuss several algorithms to perform complete exchange on a two dimensional mesh connected computer with wormhole routing. We propose algorithms for both powerof -two and non power-of-two meshes as well as an algorithm which works for any arbitrary mesh. We have developed analytical models to estimate the performance of the algorithms on the basis of system parameters. These models take into account the effects of link contention and other characteristics of the communication system. Performance results on the Intel Touchstone Delta are presented …

Genetic Algorithms For Stochastic Flow Shop No Wait Scheduling, Harpal Maini, Ubirajara R. Ferreira

Electrical Engineering and Computer Science - Technical Reports

ln this paper we present Genetic Algorithms - evolutionary algorithms based on an analogy with natural selection and survival of the fittest - applied to an NP Complete combinatorial optimization problem: minimizing the makespan of a Stochastic Flow Shop No Wait (FSNW) schedule. This is an important optimization criteria in real-world situations and the problem itself is of practical significance. We restrict our applications to the three machine flow shop no wait problem which is known to be NP complete. The stochastic hypothesis is that the processing times of jobs are described by normally distributed random variables. We discuss how …

Pseudobases In Direct Powers Of An Algebra, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

A subset P of an abstract algebra A is a pseudobasis if every function from P into A extends uniquely to an endomorphism on A. A is called K-free has a pseudobasis of cardinality K; A is minimally free if A has a pseudobasis. (The 0-free algebras are "rigid" in the strong sense; the 1-free groups are always abelian, and are precisely the additive groups of E-rings.) Our interest here is in the existence of pseudobases in direct powers A^I of an algebra A. On the positive side, if A is a rigid …

Graduate Bulletin, 1993-1995, Moorhead State University

Graduate Bulletins (Catalogs)

No abstract provided.

On Transactional Workflows, Amit P. Sheth, Marek Rusinkiewicz

Kno.e.sis Publications

The basic transaction model has evolved over time to incorporate more complex transactions structures and to take the advantage of semantics of higher-level operations that cannot be seen at the level of page reads and writes. Well known examples of such extended transaction models include nested and multi-level transactions. A number of relaxed transaction models have been defined in the last several years that permit a controlled relaxation of the transaction isolation and atomicity to better match the requirements of various database applications. Correctness criteria other than global serializability have also been proposed. Several examples of extended/relaxed transaction models are …

Simulation Modeling Of Prehospital Trauma Care, Robert L. Wears

UNF Graduate Theses and Dissertations

Prehospital emergency care systems are complex and do not necessarily respond predictably to changes in management. A combined discrete-continuous simulation model focusing on trauma care was designed and implemented in SIMSCRIPT II.5 to allow prediction of the systems response to policy changes in terms of its effect on the system and on patient survival.

The utility of the completed model was demonstrated by the results of experiments on triage and helicopter dispatching policies. Experiments on current and two alternate triage policies showed that helicopter utilization is significantly increased by more liberal triage to Level 1 trauma centers, which was expected, …

A Study Of Dynamic Optimization Techniques: Lessons And Directions In Kernel Design, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The Synthesis kernel [21,22,23,27,28] showed that dynamic code generation, software feedback, and fine-grain modular kernel organization are useful implementation techniques for improving the performance of operating system kernels. In addition, and perhaps more importantly, we discovered that there are strong interactions between the techniques. Hence, a careful and systematic combination of the techniques can be very powerful even though each one by itself may have serious limitations. By identifying these interactions we illustrate the problems of applying each technique in isolation to existing kernels. We also highlight the important common under-pinnings of the Synthesis experience and present our ideas on …

Collaborative Multimedia Scientific Design In Shastra, Vinod Anupam, Chandrajit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.

Distributed Modeling And Rendering Of Splines Using Ganith And Splinex, Chandrajit L. Bajaj, Jindon Chen, Susan B. Evans

Department of Computer Science Technical Reports

No abstract provided.

A Coarse-Grained, Architecture-Independent Approach For Connected Component Labeling, Mikhail J. Atallah, Frank Dehne, Susanne E. Hambrusch

Department of Computer Science Technical Reports

No abstract provided.

An Optimal Algorithm For Shortest Paths On Weighted Interval And Circular-Arc Graphs With Applications, Mikhail J. Atallah, Danny Z. Chen, D. T. Lee

Department of Computer Science Technical Reports

No abstract provided.

Topologically Correct Approximations Of Arbitrary Rational Parametric, Chandrajit L. Bajaj, Andrew V. Royappa

Department of Computer Science Technical Reports

No abstract provided.

A Unifying Approach To Hierarchical Transaction Management In Multidatabase Systems, Ahmed K. Almagarmid, Aidong Zhang

Department of Computer Science Technical Reports

No abstract provided.

The Extent Of Multimedia Computer Applications In The Business World, Mei Yee Lim

Honors Theses

The world, or at least I, was all agog when touch screens arrived. My initial contact with touch screens was at a science exhibition in Menara MPPJ, Petaling Jaya, Malaysia in July 1987. That particular exhibit, which encouraged visitors to participate and to experiment with, was a graphic program. Visitors could use their fingers to select the drawing tool or the color they want (which is something like the tools on a MacDraw screen on a Macintosh) and use their fingers to move around the screen to draw anything they want. That added to my fascination with the world of …

Development Of A Classification System For Computer Viruses In The Ibm Pc Environment Using The Dos Operating System, Hugh R. Browne

Theses : Honours

The threat to computers worldwide from computer viruses is increasing as new viruses and variants proliferate. Availability of virus construction tools to facilitate 'customised' virus production and wider use of more sophisticated means of evading detection, such as encryption, polymorphic transformation and memory resident 'stealth' techniques increase this problem. Some viruses employ methods to guard against their own eradication from an infected computer, whilst other viruses adopt measures to prevent disassembly of the virus for examination and analysis. Growth in computer numbers and connectivity provide a growing pool of candidate hosts for infection. Standardised and flexible systems for classification and …

A Unified Model For Shared-Memory And Message-Passing Systems, Kenneth Goldman, Katherine Yelick

All Computer Science and Engineering Research

A unified model of distributed systems that accomodates both shared-memory and message-passing communication is proposed. An extension of the I/O automaton model of Lynch and Tuttle, the model provides a full range of types of atomic accesses to shared memory, from basic reads and writes to read-modify-write. In addition to supporting the specification and verification of shared memory algorithms, the unified model is particularly helpful for proving correspondences between atomic shared objects and invocation-response systems and for proving the correctness of systems that contain both message passing and shared memory (such as a network of shared-memory multiprocessors or a distributed …

Symphony: A Hardware, Operating System, And Protocol Processing Architecture For Distributed Multimedia Applications, Andreas D. Bovopoulos, R. Gopalakrishnan, Saied Hosseini

All Computer Science and Engineering Research

This paper explores the architectural requirements for computers to be able to process multimedia data streams such as video and audio. The I/O subsystem is shown to be a bottleneck, and a network backplane approach is suggested to alleviate this. The need to provide end-to-end performance guarantees requires predictable performance of intra-machine communication, and a schedulable bus with reservation is proposed to achieve this. In addition this requires operating system (OS) mechanisms to negotiate and enforce QoS requirements of applications. A real-time microkernel executive is proposed for each autonomous unit. Requirements for real-time microkernel exeutive is proposed for each autonomous …

Formal Method For Scheduling, Routing And Communication Protocol, Lenore Mullin, S. A. Thibault, D. R. Dooling, E. A. Sandberg

Computer Science Faculty Research & Creative Works

The PRAM model has been shown to be an optimal design for emulating both loose and tightly coupled multiprocessors for unit time operations. When virtual processors are required, multiplexing work to available processors is employed. This introduces a form of latency incurred by operating system overhead. Further complications arise when bandwidth creates bottlenecking of work units. G.E. Blelloch (1989) showed how to add parallel prefix operations (scans) to an extended PRAM model which uses unit step, not time operations. This paper shows how the psi) calculus can be used to group work units, i.e., pipelining the work units, so that …

An Investigation Of Methodologies For Software Development Prototyping, Susan M. Jones

Theses: Doctorates and Masters

The computer industry has a poor record of system development using the traditional life-cycle approach. The main cause of user dissatisfaction is the unacceptably large amount of time between specification and delivery of a system. In addition, users have limited opportunity to influence how the system will look when implemented once development has commenced. With the advent of 4GLs, system development using a prototyping approach has become a viable option. This has reduced the development tlme significantly and, together with the use of prototyping, has allowed users to become more involved in the development process. However, this change in the …

The Use Of A Factory Simulation To Evaluate A Flexible Control Structure For Integrated Manufacturing, Ling Ling Pan

Engineering Management & Systems Engineering Theses & Dissertations

Once a control structure for an integrated manufacturing system is decided upon, manufacturing activities are limited by that structure. A flexible control structure is presented as an approach for accommodating a variety of manufacturing activities, without being limited to a single control structure. A flexible control structure is one that allows multiple types of control structure in the manufacturing process. For example, both hierarchical and non-hierarchical structures may be used in a flexible structure. The properties of a flexible control structure are discussed from the point of view of graph theory.

Control structures for automated manufacturing are difficult to evaluate …

Intel Nx To Pvm 3.2 Message Passing Conversion Library, Trey Arthur, Michael L. Nelson

Computer Science Faculty Publications

NASA Langley Research Center has developed a library that allows Intel NX message passing codes to be executed under the more popular and widely supported Parallel Virtual Machine (PVM) message passing library. PVM was developed at Oak Ridge National Labs and has become the defacto standard for message passing. This library will allow the many programs that were developed on the Intel iPSC/860 or Intel Paragon in a Single Program Multiple Data (SPMD) design to be ported to the numerous architectures that PVM (version 3.2) supports. Also, the library adds global operations capability to PVM. A familiarity with Intel NX …

A Comparison Of Queueing, Cluster And Distributed Computing Systems, Joseph A. Kaplan, Michael L. Nelson

Computer Science Faculty Publications

Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in …

A Rule-Based System For Query Feedback, Hock C. Chan, Kwok-Kee Wei, Keng Siau

Research Collection School Of Computing and Information Systems

The authors propose a rule-based system which provides feedback in order to give the user a better understanding of the user's queries. This technique improves query accuracy and confidence. A rule-based expert system that pinpoints syntax errors is described. It suggests possible semantics errors and provides possible solutions, as well as the English translation for the queries. The system can be used for computer-aided training and in actual operations. The system was experimentally tested with a group of students.

Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr.

Theses and Dissertations

The Air Force Institute of Technology is continuing research in the Virtual Cockpit. The Virtual Cockpit makes use of high performance graphics workstations, Virtual Environment technology, and Distributed Interactive Simulation network protocols to create a flight simulator based on the capabilities of the McDonnell Douglas F-15E Strike Eagle. The work presented in this thesis focuses on the design and implementation issues for integrating a weapons delivery capability. Weapons simulated include: RADAR and IR guided air- to-air missiles, gravity and precision guided bombs, and a 20mm cannon. Virtual Environment displays used include: color NTSC and monochrome high resolution helmet mounted displays …