Benchmarking hypercube hardware and software

It was long a truism in computer systems design that balanced systems achieve the best performance. Message passing parallel processors are no different. To quantify the balance of a hypercube design, an experimental methodology was developed and the associated suite of benchmarks was applied to several existing hypercubes. The benchmark suite includes tests of both processor speed in the absence of internode communication and message transmission speed as a function of communication patterns

Evaluating Factors Contributing to Engineering Technology Students\u27 Introductory Physics Experience

The UMaine’s introductory algebra-based physics course PHY 107 is dedicated to students from the School of Engineering Technology (SET). These SET students come from a wide range of backgrounds and are studying a hybrid of curricula for an engineer and a technician with a leaning toward engineering. In order to appropriately serve this population we must attempt to understand who these students are. One of the legends surrounding this group is that their struggles with physics stem from having a lower level of mathematics ability than the typical introductory physics student. Through the use of a math diagnostic, the Force and Motion Conceptual Evaluation (FMCE), an updated version of the Maryland Physics Expectations (MPEX2) survey, and a myriad of student, instructor, and SET Coordinator interviews, I sought to develop a data supported view of the PHY 107 students. In this process, I address current course objectives; the extent students develop toward those objectives; and find which factors correlate with physics conceptual development. I found that despite SET’s professional concerns, they care most about developing their students’ abilities to make sense of physical and verbal representations of a situation and translate that understanding into meaningful mathematical models. The measure of conceptual development tells the extent to which PHY 107 has developed these skills necessary to build a mathematical model. PHY 107 students only improved ˜12% of their potential for conceptual development as measured by the FMCE. Mathematic skill failed to contribute to the PHY 107 students’ conceptual gain , though they do represent the bottom quartile of a typical algebra-based introductory physics course. Of all factors considered in this study, pre- and post-instruction favorable attitudes as measured by MPEX2 coherence and concept cluster scores best-predicted student conceptual development

Analysis of adaptive algorithms for an integrated communication network

Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes

MPF: A portable message passing facility for shared memory multiprocessors

The design, implementation, and performance evaluation of a message passing facility (MPF) for shared memory multiprocessors are presented. The MPF is based on a message passing model conceptually similar to conversations. Participants (parallel processors) can enter or leave a conversation at any time. The message passing primitives for this model are implemented as a portable library of C function calls. The MPF is currently operational on a Sequent Balance 21000, and several parallel applications were developed and tested. Several simple benchmark programs are presented to establish interprocess communication performance for common patterns of interprocess communication. Finally, performance figures are presented for two parallel applications, linear systems solution, and iterative solution of partial differential equations

Parallel discrete event simulation: A shared memory approach

With traditional event list techniques, evaluating a detailed discrete event simulation model can often require hours or even days of computation time. Parallel simulation mimics the interacting servers and queues of a real system by assigning each simulated entity to a processor. By eliminating the event list and maintaining only sufficient synchronization to insure causality, parallel simulation can potentially provide speedups that are linear in the number of processors. A set of shared memory experiments is presented using the Chandy-Misra distributed simulation algorithm to simulate networks of queues. Parameters include queueing network topology and routing probabilities, number of processors, and assignment of network nodes to processors. These experiments show that Chandy-Misra distributed simulation is a questionable alternative to sequential simulation of most queueing network models