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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Programming the Navier-Stokes computer: An abstract machine model and a visual editor

The Navier-Stokes computer is a parallel computer designed to solve Computational Fluid Dynamics problems. Each processor contains several floating point units which can be configured under program control to implement a vector pipeline with several inputs and outputs. Since the development of an effective compiler for this computer appears to be very difficult, machine level programming seems necessary and support tools for this process have been studied. These support tools are organized into a graphical program editor. A programming process is described by which appropriate computations may be efficiently implemented on the Navier-Stokes computer. The graphical editor would support this programming process, verifying various programmer choices for correctness and deducing values such as pipeline delays and network configurations. Step by step details are provided and demonstrated with two example programs.

Middleton, David↗
NASA NTRS1985

Thermal Barrier Coatings. Abstracts and figures

The Thermal Barrier Coatings Workshop was held May 21 and 22, 1985, at the NASA Lewis Research Center in Cleveland, Ohio. Six sessions covered Failure Mechanisms and Life Modeling, Effects of Oxidation and Creep, Phase Stability and Microstructural Aspects, Nondestructive and Analytical Assessment, Coating Development, and Alternative Applications.

Source record↗
NASA NTRS1988

Polar Ozone Workshop. Abstracts

Results of the proceedings of the Polar Ozone Workshop held in Snowmass, CO, on May 9 to 13, 1988 are given. Topics covered include ozone depletion, ozonometry, polar meteorology, polar stratospheric clouds, remote sensing of trace gases, atmospheric chemistry and dynamical simulations.

Aikin, Arthur C.↗
NASA NTRS1986

Some design constraints required for the use of generic software in embedded systems: Packages which manage abstract dynamic structures without the need for garbage collection

The embedded systems running real-time applications, for which Ada was designed, require their own mechanisms for the management of dynamically allocated storage. There is a need for packages which manage their own internalo structures to control their deallocation as well, due to the performance implications of garbage collection by the KAPSE. This places a requirement upon the design of generic packages which manage generically structured private types built-up from application-defined input types. These kinds of generic packages should figure greatly in the development of lower-level software such as operating systems, schedulers, controllers, and device driver; and will manage structures such as queues, stacks, link-lists, files, and binary multary (hierarchical) trees. Controlled to prevent inadvertent de-designation of dynamic elements, which is implicit in the assignment operation A study was made of the use of limited private type, in solving the problems of controlling the accumulation of anonymous, detached objects in running systems. The use of deallocator prodecures for run-down of application-defined input types during deallocation operations during satellites.

Johnson, Charles S.↗
NASA NTRS1986

Reusable software parts and the semi-abstract data type

The development of reuable software parts has been an area of intense discussion within the software community for many years. An approach is described for developing reusable parts for the applications of missile guidance, navigation and control which meet the following criteria: (1) Reusable; (2) Tailorable; (3) Efficient; (4) Simple to use; and (5) Protected against misuse. Validating the feasibility of developing reusable parts which possess these characteristics is the basis of the Common Ada Missile Packages Program (CAMP). Under CAMP, over 200 reusable software parts were developed, including part for navigation, Kalman filter, signal processing and autopilot. Six different methods are presented for designing reusable software parts.

Cohen, Sanford G.↗
NASA NTRS1989

Objects as closures: Abstract semantics of object oriented languages

We discuss denotational semantics of object-oriented languages, using the concept of closure widely used in (semi) functional programming to encapsulate side effects. It is shown that this denotational framework is adequate to explain classes, instantiation, and inheritance in the style of Simula as well as SMALLTALK-80. This framework is then compared with that of Kamin, in his recent denotational definition of SMALLTALK-80, and the implications of the differences between the two approaches are discussed.

Reddy, Uday S.↗
NASA NTRS1989

Space Electrochemical Research and Technology Conference: Abstracts

The objectives of the conference were to examine current technologies, research efforts, and advanced ideas, and to identify technical barriers which affect the advancement of electrochemical energy storage systems for space applications. Papers were presented and workshops were conducted in four technical areas: advanced concepts, hydrogen-oxygen fuel cells and electrolyzers, the nickel electrode, and advanced rechargeable batteries.

Source record↗
NASA NTRS1988

Objects as closures - Abstract semantics of object oriented languages

The denotational semantics of object-oriented languages is discussed using the concept of closure widely used in (semi) functional programming to encapsulate side effects. It is shown that this denotational framework is adequate to explain classes, instantiation, and inheritance in the style of Simula as well as SMALLTALK-80. This framework is then compared with that of Kamin (1988), in his recent denotational definition of SMALLTALK-80, and the implications of the differences between the two approaches are discussed.

Reddy, Uday S.↗
NASA NTRS1987

Definition of tolerance to continuous hyperoxia in man - An abstract report of Predictive Studies V

The overall goals, design, and procedures of Predictive Studies V are discussed as well as the specific elements of neural effects produced by prolonged hyperoxia. It is noted that Predictive Studies V study of oxygen poisoning in normal men during uninterrupted exposures to oxygen over the range of hyperbaric oxygen exposure most useful in diving, the treatment of gas lesion diseases, and general hyperbaric medicine. It is found that, throughout the study, the most striking observations were related to effects on visual function, on the lung, and the probable interactions of preconvulsive neural activity with effects on cardiovascular and respiratory-pulmonary functions.

Lambertsen, C. J.↗
NASA NTRS1989

Small business innovation research. Abstracts of completed 1987 phase 1 projects

Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered.

Source record↗
NASA NTRS1990

Knowledge management: An abstraction of knowledge base and database management systems

Artificial intelligence application requirements demand powerful representation capabilities as well as efficiency for real-time domains. Many tools exist, the most prevalent being expert systems tools such as ART, KEE, OPS5, and CLIPS. Other tools just emerging from the research environment are truth maintenance systems for representing non-monotonic knowledge, constraint systems, object oriented programming, and qualitative reasoning. Unfortunately, as many knowledge engineers have experienced, simply applying a tool to an application requires a large amount of effort to bend the application to fit. Much work goes into supporting work to make the tool integrate effectively. A Knowledge Management Design System (KNOMAD), is described which is a collection of tools built in layers. The layered architecture provides two major benefits; the ability to flexibly apply only those tools that are necessary for an application, and the ability to keep overhead, and thus inefficiency, to a minimum. KNOMAD is designed to manage many knowledge bases in a distributed environment providing maximum flexibility and expressivity to the knowledge engineer while also providing support for efficiency.

Riedesel, Joel D.↗
NASA NTRS1989

Middle Atmosphere Program. Handbook for MAP, volume 29. Part 1: Extended Abstracts, International Symposium on Solar Activity Forcing of the Middle Atmosphere. Part 2: MASH Workshop

The proceedings of the symposium is presented. Eight different sessions were presented: (1) Papers generally related to the subject; (2) Papers on the influence of the Quasi Biennial Oscillation; (3) Papers on the influence of the solar electromagnetic radiation variability; (4) Papers on the solar wind and high energy particle influence; (5) Papers on atmospheric circulation; (6) Papers on atmospheric electricity; (7) Papers on lower ionospheric variability; and (8) Solar posters, which are not included in this compilation.

Lastovicka, Jan↗
NASA NTRS1989

Machine characterization based on an abstract high-level language machine

Measurements are presented for a large number of machines ranging from small workstations to supercomputers. The authors combine these measurements into groups of parameters which relate to specific aspects of the machine implementation, and use these groups to provide overall machine characterizations. The authors also define the concept of pershapes, which represent the level of performance of a machine for different types of computation. A metric based on pershapes is introduced that provides a quantitative way of measuring how similar two machines are in terms of their performance distributions. The metric is related to the extent to which pairs of machines have varying relative performance levels depending on which benchmark is used.

Saavedra-Barrera, Rafael H.↗