291 research outputs found
Execution models for mapping programs onto distributed memory parallel computers
The problem of exploiting the parallelism available in a program to efficiently employ the resources of the target machine is addressed. The problem is discussed in the context of building a mapping compiler for a distributed memory parallel machine. The paper describes using execution models to drive the process of mapping a program in the most efficient way onto a particular machine. Through analysis of the execution models for several mapping techniques for one class of programs, we show that the selection of the best technique for a particular program instance can make a significant difference in performance. On the other hand, the results of benchmarks from an implementation of a mapping compiler show that our execution models are accurate enough to select the best mapping technique for a given program
Project Towards No Drug Abuse: A Review of the Findings and Future Directions
Objective: To provide a review of the evidence from 3 experimental trials of Project Towards No Drug Abuse (TND), a senior high-school-based drug abuse prevention program.Methods: Theoretical concepts, subjects, designs, hypotheses, findings, and conclusions of these trials are presented. A total of 2,468 high school youth from 42 schools in southern California were surveyed.Results: The Project TND curriculum shows reductions in the use of cigarettes, alcohol, marijuana, hard drugs, weapon carrying, and victimization. Most of these results were replicated across the 3 trials. Conclusion: Project TND is an effective drug and violence prevention program for older teens, at least for one year follow-up
An integrated runtime and compile-time approach for parallelizing structured and block structured applications
Scientific and engineering applications often involve structured meshes. These meshes may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). A combined runtime and compile-time approach for parallelizing these applications on distributed memory parallel machines in an efficient and machine-independent fashion was described. A runtime library which can be used to port these applications on distributed memory machines was designed and implemented. The library is currently implemented on several different systems. To further ease the task of application programmers, methods were developed for integrating this runtime library with compilers for HPK-like parallel programming languages. How this runtime library was integrated with the Fortran 90D compiler being developed at Syracuse University is discussed. Experimental results to demonstrate the efficacy of our approach are presented. A multiblock Navier-Stokes solver template and a multigrid code were experimented with. Our experimental results show that our primitives have low runtime communication overheads. Further, the compiler parallelized codes perform within 20 percent of the code parallelized by manually inserting calls to the runtime library
Prospective Minority Students\u27 Perceptions of Application Packets for Professional Psychology Programs: A Qualitative Study
This article reports the results of a qualitative study designed to determine issues salient in Black and Hispanic American students\u27 review and evaluation of program-application packets in professional psychology. The study served as an extension to the Yoshida et al. (1989) quantitative investigation. Students interested in pursuing doctoral studies in counseling or school psychology (N = 22) served as the sample. The qualitative methodology incorporated a think-aloud procedure and semistructured interviews. A theme analysis of transcribed interviews identified both major and minor themes central to participants\u27 evaluation of the packets. Major themes included financial aid, program requirements and course descriptions, demography of the student body, and the quality and clarity of application material. Specific suggestions on developing an application packet to send to inquiring prospective students are put forth. It is recommended that such a packet could serve as a cost-effective minority-recruitment strategy
Minority Student Perceptions of Professional Pscyhology Application Packets: A Qualitative Study
This article reports the results of a qualitative study designed to determine issues salient in Black and Hispanic American students\u27 review and evaluation of program-application packets in professional psychology. The study served as an extension to the Yoshida et al. (1989) quantitative investigation. Students interested in pursuing doctoral studies in counseling or school psychology (N = 22) served as the sample. The qualitative methodology incorporated a think-aloud procedure and semistructured interviews. A theme analysis of transcribed interviews identified both major and minor themes central to participants\u27 evaluation of the packets. Major themes included financial aid, program requirements and course descriptions, demography of the student body, and the quality and clarity of application material. Specific suggestions on developing an application packet to send to inquiring prospective students are put forth. It is recommended that such a packet could serve as a costeffective minority-recruitment strategy
Multiple Range Query Optimization with Distributed Cache Indexing
MQO is a distributed multiple query processing middleware that can
optimize query processing for data analysis applications on the Grid. It
has one or more proxies that act as front-end to a collection of backend
servers. The basic idea behind this architecture is semantic caching,
whereby queries can leverage available cached results in the proxy either
directly or through transformations. While this approach has been shown
to speed up query evaluation under multi-client workloads, the caching
infrastructure in the backend servers is not well used for query planning.
In this paper, we describe a distributed multidimensional indexing scheme
that enables the proxy to directly consider the cache contents available
at the backend servers for planning and scheduling. This approach is shown
to produce better query plans and faster query response times. We
experimentally demonstrate that system throughput can be improved up to
66%, compared to either load-based or round-robin scheduling
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