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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

An Approach to Evaluate Scientist Support in Abstract Workflows and Provenance Traces

Abstract workflows are useful to bridge the gap between scientists and technologists towards using computer systems to carry out scientific processes. Provenance traces provide evidence required to validate results and support their reuse. Assuming both technologies are based on formal semantics, a knowledge-based system that consistently merges both technologies is useful for scientists that produce data to document their data collecting and transformation processes; it is also useful for scientists that reuse data to assess scientific processes and resulting datasets produced by others. While evaluation of each technology is necessary for a given application, this work discusses their combined evaluation. The claim is that both technologies should complement each other and align consistently to a scientist’s perspective in order to be effective for science. Evaluation criteria are proposed based on lessons learned and exemplified for discussion.

Provenance↗
DOE OSTI2013

Toward Abstracting the Communication Intent in Applications to Improve Portability and Productivity

Programming with communication libraries such as the Message Passing Interface (MPI) obscures the high-level intent of the communication in an application and makes static communication analysis difficult to do. Compilers are unaware of communication libraries specifics, leading to the exclusion of communication patterns from any automated analysis and optimizations. To overcome this, communication patterns can be expressed at higher-levels of abstraction and incrementally added to existing MPI applications. In this paper, we propose the use of directives to clearly express the communication intent of an application in a way that is not specific to a given communication library. Our communication directives allow programmers to express communication among processes in a portable way, giving hints to the compiler on regions of computations that can be overlapped with communication and relaxing communication constraints on the ordering, completion and synchronization of the communication imposed by specific libraries such as MPI. The directives can then be translated by the compiler into message passing calls that efficiently implement the intended pattern and be targeted to multiple communication libraries. Thus far, we have used the directives to express point-to-point communication patterns in C, C++ and Fortran applications, and have translated them to MPI and SHMEM.

Mintz, Tiffany M↗
DOE OSTI2012

RRS 2012 Abstract Book

Abstracts presented at the 2012 Annual Meeting of the Radiation Research Society.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗