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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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Collection of subprograms brings to Ada many features from other programming languages. All generic packages designed to be easily instantiated for types declared in user's facility. Most packages have widespread applicability, although some oriented for avionics applications. All designed to facilitate writing new software in Ada. Written on IBM/AT personal computer running under PC DOS, v.3.1.
GRODY developed alongside GROSS computer program (GSC-13147), a FORTRAN dynamics-simulator program performing same functions. GRODY conceived for use in case study to assess feasibility and effectiveness of Ada programming language for development of flight-dynamics software. Designed for those familiar with analysis of attitudes of spacecraft. Supports planning of maneuvers as well as analytical testing and evaluation of attitude-determination and -control system used on board Gamma-Ray Observatory (GRO) satellite. Simulates computer and control processor electronics aboard GRO satellite. Enables analyst to check and update commands sent from ground and values of parameters, obtain displays of status of simulation, interrupt simulation, analyze previous runs, and obtain printed output of simulation runs. Written mainly in Ada (99 percent) with remainder in FORTRAN.
Surface Shading computer program, SURF, developed in support of work of Computational Fluid Dynamics (CFD). Part of CFD graphics software. Accepts input in form of grid and solution files otherwise normally fed to Ames Research Center's version of PLOT3D software from "flow solver" programs. Interactively creates wire-frame, shaded, and function-map parts viewed and then transferred to Ames Research Graphic (ARCGRAPH) standard files, animated with GAS (COSMIC Program ARC-12379). Written in C programming language and requires Silicon Graphics "include" files (e.g., stdio.h, gl.h).
CAMRAD, program designed for rapid input and retrieval of all data used in engineering-to-manufacturing support operations, aids engineer by automating material-review-disposition process. Facilitates research of material-review histories and provides for efficient processing of material-review documents. Three SmartWare project files control operation. Written in Smart programming language and designed to run on IBM PC compatibles with SmartWave version 3.1.
Report discusses spatial-operator algebra developed in recent studies of mathematical modeling, control, and design of trajectories of robotic manipulators. Provides succinct representation of mathematically complicated interactions among multiple joints and links of manipulator, thereby relieving analyst of most of tedium of detailed algebraic manipulations. Presents analytical formulation of spatial-operator algebra, describes some specific applications, summarizes current research, and discusses implementation of spatial-operator algebra in the Ada programming language.
Approach to solution of nonlinear ordinary differential equations involves transfer functions based on recently-introduced Laplace-Borel and Fourier-Borel transforms. Main theorem gives transform of response of nonlinear system as Cauchy product of transfer function and transform of input function of system, together with memory effects. Used to determine responses of electrical circuits containing variable inductances or resistances. Also possibility of doing all noncommutative algebra on computers in such symbolic programming languages as Macsyma, Reduce, PL1, or Lisp. Process of solution organized and possibly simplified by algebraic manipulations reducing integrals in solutions to known or tabulated forms.
Programmable maintenance processor (MAINT) made of commercially available integrated circuits. Autonomous one of four digital electronic processors in extended aircraft interrogation and display system (XAIDS). Developed for testing of system and application computer programs as well as for testing equipment. MAINT has independent terminal and printer interfaces and dedicated magnetic bubble memory storing system-testing sequences entered from terminal. Software for MAINT written in PLM86 programming language and broken into four separate modules.
User does not have to add any special logic to aid in synchronization. Time Warp Operating System (TWOS) computer program is special-purpose operating system designed to support parallel discrete-event simulation. Complete implementation of Time Warp mechanism. Supports only simulations and other computations designed for virtual time. Time Warp Simulator (TWSIM) subdirectory contains sequential simulation engine interface-compatible with TWOS. TWOS and TWSIM written in, and support simulations in, C programming language.
The principal objectives are to develop methods for assessing the likelihood of wind shear encounter (based on real-time information in the cockpit), for deciding what flight path to pursue (e.g., takeoff abort, landing go-around, or normal climbout or glide slope), and for using the aircraft's full potential for combating wind shear. This study requires the definition of both deterministic and statistical techniques for fusing internal and external information, for making go/no-go decisions, and for generating commands to the aircraft's autopilot and flight directors for both automatic and manually controlled flight. The expert system for pilot aiding is based on the results of the FAA Windshear Training Aids Program, a two-volume manual that presents an overview, pilot guide, training program, and substantiating data that provides guidelines for this initial development. The Windshear Safety Advisor expert system currently contains over 140 rules and is coded in the LISP programming language for implementation on a Symbolics 3670 LISP Machine.
The semi-annual status report covers activities of the ISIS project during the second half of 1989. The project had several independent objectives: (1) At the level of the ISIS Toolkit, ISIS release V2.0 was completed, containing bypass communication protocols. Performance of the system is greatly enhanced by this change, but the initial software release is limited in some respects. (2) The Meta project focused on the definition of the Lomita programming language for specifying rules that monitor sensors for conditions of interest and triggering appropriate reactions. This design was completed, and implementation of Lomita is underway on the Meta 2.0 platform. (3) The Deceit file system effort completed a prototype. It is planned to make Deceit available for use in two hospital information systems. (4) A long-haul communication subsystem project was completed and can be used as part of ISIS. This effort resulted in tools for linking ISIS systems on different LANs together over long-haul communications lines. (5) Magic Lantern, a graphical tool for building application monitoring and control interfaces, is included as part of the general ISIS releases.
The objective is the development of methods, technology, and skills that will enable NASA to cost-effectively specify, build, and manage reliable software which can evolve and be maintained over an extended period. The need for such software is rooted in the increasing integration of software and computing components into NASA systems. Current NASA Software Engineering expertise was applied toward some of the largest reliable systems including: shuttle launch; ground support; shuttle simulation; minor control; satellite tracking; and scientific data systems. Unfortunately, no theory exists for reliable complex software systems. NASA is seeking to fill this theoretical gap through a number of approaches. One such approach is to conduct research on theoretical foundations for managing complex software systems. It includes: communication models, new and modified paradigms, and life-cycle models. Another approach is research in the theoretical foundations for reliable software development and validation. It focuses upon formal specifications, programming languages, software engineering systems, software reuse, formal verification, and software safety. Further approaches involve benchmarking a NASA software environment, experimentation within the NASA context, evolution of present NASA methodology, and transfer of technology to the space station software support environment.
The development of computer science has produced a vast number of machine architectures, programming languages, and compiler technologies. The cross product of these three characteristics defines the spectrum of previous and present data representation methodologies. With regard to computer networks, the uniqueness of these methodologies presents an obstacle when disparate host environments are to be interconnected. Interoperability within a heterogeneous network relies upon the establishment of data representation commonality. The International Standards Organization (ISO) is currently developing the abstract syntax notation one standard (ASN.1) and the basic encoding rules standard (BER) that collectively address this problem. When used within the presentation layer of the open systems interconnection reference model, these two standards provide the data representation commonality required to facilitate interoperability. The details of a compiler that was built to automate the use of ASN.1 and BER are described. From this experience, insights into both standards are given and potential problems relating to this development effort are discussed.
The sensor validation and data reconstruction task reviewed relevant literature and selected applicable validation and reconstruction techniques for further study; analyzed the selected techniques and emphasized those which could be used for both validation and reconstruction; analyzed Space Shuttle Main Engine (SSME) hot fire test data to determine statistical and physical relationships between various parameters; developed statistical and empirical correlations between parameters to perform validation and reconstruction tasks, using a computer aided engineering (CAE) package; and conceptually designed an expert system based knowledge fusion tool, which allows the user to relate diverse types of information when validating sensor data. The host hardware for the system is intended to be a Sun SPARCstation, but could be any RISC workstation with a UNIX operating system and a windowing/graphics system such as Motif or Dataviews. The information fusion tool is intended to be developed using the NEXPERT Object expert system shell, and the C programming language.
Software engineering ethics is reviewed. The following subject areas are covered: lack of a system viewpoint; arrogance of PC DOS software vendors; violation od upward compatibility; internet worm; internet worm revisited; student cheating and company hiring interviews; computing practitioners and the commodity market; new projects and old programming languages; schedule and budget; and recent public domain comments.
Information on the Ada programming language is given. Topics covered include computer graphics, uniformity issues, Ada maintenance, and real time extensions.
This survey examines 39 parallel programming tools. Focus is placed on those tool capabilites needed for parallel scientific programming rather than for general computer science. The tools are classified with current and future needs of Numerical Aerodynamic Simulator (NAS) in mind: existing and anticipated NAS supercomputers and workstations; operating systems; programming languages; and applications. They are divided into four categories: suggested acquisitions, tools already brought in; tools worth tracking; and tools eliminated from further consideration at this time.
The Transportable Applications Environment Plus (TAE PLUS), developed at NASA's Goddard Space Flight Center, is a portable What You See Is What You Get (WYSIWYG) user interface development and management system. Its primary objective is to provide an integrated software environment that allows interactive prototyping and development that of user interfaces, as well as management of the user interface within the operational domain. Although TAE Plus is applicable to many types of applications, its focus is supporting user interfaces for space applications. This paper discusses what TAE Plus provides and how the implementation has utilized state-of-the-art technologies within graphic workstations, windowing systems and object-oriented programming languages.
This is a bibliography on numerical methods. It also includes a number of other references on machine architecture, programming language, and other topics of interest to scientific computing. Certain conference proceedings and anthologies which have been published in book form are also listed.