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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 901 records · Page 50

Classification software technique assessment

A catalog of software options is presented for the use of local user communities to obtain software for analyzing remotely sensed multispectral imagery. The resources required to utilize a particular software program are described. Descriptions of how a particular program analyzes data and the performance of that program for an application and data set provided by the user are shown. An effort is made to establish a statistical performance base for various software programs with regard to different data sets and analysis applications, to determine the status of the state-of-the-art.

Jayroe, R. R., Jr.↗

A method for reducing software life cycle costs

The advent of new hardware and software tools permits a new approach to preparing, presenting, and maintaining software specifications and corresponding source programs. Any real reduction in software life cycle costs must make highly skilled human effort more efficient especially on large, complex, and long-lasting software projects. When these skilled human functions are examined closely, it is seen that critical factors include the way one communicates with oneself and then with others and finally with computers. Thus, there has been a long and active proliferation of programming languages and, more recently, a number of programming design languages to supplement older methods, such as flowcharting. One way to achieve cost reduction is to provide documentation tools whose use increases the effectiveness of skilled humans.

Paine, W. O.↗

Software engineering project management - A state-of-the-art report

The management of software engineering projects in the aerospace industry was investigated. The survey assessed such features as contract type, specification preparation techniques, software documentation required by customers, planning and cost-estimating, quality control, the use of advanced program practices, software tools and test procedures, the education levels of project managers, programmers and analysts, work assignment, automatic software monitoring capabilities, design and coding reviews, production times, success rates, and organizational structure of the projects.

Thayer, R. H.↗

MUST - An integrated system of support tools for research flight software engineering

The objectives of NASA's MUST (Multipurpose User-oriented Software Technology) program at Langley Research Center are to cut the cost of producing software which effectively utilizes digital systems for flight research. These objectives will be accomplished by providing an integrated system of support software tools for use throughout the research flight software development process. A description of the overall MUST program and its progress toward the release of a first MUST system will be presented. This release includes: a special interactive user interface, a library of subroutines, assemblers, a compiler, automatic documentation tools, and a test and simulation system.

Straeter, T. A.↗

Tools for Embedded Computing Systems Software

A workshop was held to assess the state of tools for embedded systems software and to determine directions for tool development. A synopsis of the talk and the key figures of each workshop presentation, together with chairmen summaries, are presented. The presentations covered four major areas: (1) tools and the software environment (development and testing); (2) tools and software requirements, design, and specification; (3) tools and language processors; and (4) tools and verification and validation (analysis and testing). The utility and contribution of existing tools and research results for the development and testing of embedded computing systems software are described and assessed.

Source record↗

Integrated testing and verification system for research flight software

The MUST (Multipurpose User-oriented Software Technology) program is being developed to cut the cost of producing research flight software through a system of software support tools. An integrated verification and testing capability was designed as part of MUST. Documentation, verification and test options are provided with special attention on real-time, multiprocessing issues. The needs of the entire software production cycle were considered, with effective management and reduced lifecycle costs as foremost goals.

Taylor, R. N.↗

A progress report on a NASA research program for embedded computer systems software

The paper presents the results of the second stage of the Multipurpose User-oriented Software Technology (MUST) program. Four primary areas of activities are discussed: programming environment, HAL/S higher-order programming language support, the Integrated Verification and Testing System (IVTS), and distributed system language research. The software development environment is provided by the interactive software invocation system. The higher-order programming language (HOL) support chosen for consideration is HAL/S mainly because at the time it was one of the few HOLs with flight computer experience and it is the language used on the Shuttle program. The overall purpose of IVTS is to provide a 'user-friendly' software testing system which is highly modular, user controlled, and cooperative in nature.

Foudriat, E. C.↗

Data analysis software for the autoradiographic enhancement process. Volumes 1, 2, and 3, and appendix

The computer software developed to set up a method for Wiener spectrum analysis of photographic films is presented. This method is used for the quantitative analysis of the autoradiographic enhancement process. The software requirements and design for the autoradiographic enhancement process are given along with the program listings and the users manual. A software description and program listings modification of the data analysis software are included.

Singh, S. P.↗

The software system development for the TAMU real-time fan beam scatterometer data processors

A software package was designed and written to process in real-time any one quadrature channel pair of radar scatterometer signals form the NASA L- or C-Band radar scatterometer systems. The software was successfully tested in the C-Band processor breadboard hardware using recorded radar and NERDAS (NASA Earth Resources Data Annotation System) signals as the input data sources. The processor development program and the overall processor theory of operation and design are described. The real-time processor software system is documented and the results of the laboratory software tests, and recommendations for the efficient application of the data processing capabilities are presented.

Clark, B. V.↗

DSS command software update

The modifications, additions, and testing results for a version of the Deep Space Station command software, generated for support of the Voyager Saturn encounter, are discussed. The software update requirements included efforts to: (1) recode portions of the software to permit recovery of approximately 2000 words of memory; (2) correct five Voyager Ground data System liens; (3) provide capability to automatically turn off the command processor assembly local printer during periods of low activity; and (4) correct anomalies existing in the software.

Stinnett, W. G.↗

Distributing structural optimization software between a mainframe and a minicomputer

This paper describes a distributed software system for solving large-scale structural optimization problems. Distributing the software between a mainframe computer and a minicomputer takes advantage of some of the best features available on each computer. The described software system consists of a finite element structural analysis computer program, a general purpose optimizer program, and several small user-supplied problem dependent programs. Comparison with a similar system executing entirely on the mainframe computer reveals that the distributed system costs less, uses computer resources more efficiently and improves production through faster turnaround and improved user control. The system interfaces with interactive graphics software for generating models and displaying the intermediate and final results

Rogers, J. L., Jr.↗

Integrated testing and verification system for research flight software design document

The NASA Langley Research Center is developing the MUST (Multipurpose User-oriented Software Technology) program to cut the cost of producing research flight software through a system of software support tools. The HAL/S language is the primary subject of the design. Boeing Computer Services Company (BCS) has designed an integrated verification and testing capability as part of MUST. Documentation, verification and test options are provided with special attention on real time, multiprocessing issues. The needs of the entire software production cycle have been considered, with effective management and reduced lifecycle costs as foremost goals. Capabilities have been included in the design for static detection of data flow anomalies involving communicating concurrent processes. Some types of ill formed process synchronization and deadlock also are detected statically.

Taylor, R. N.↗

SEPAC flight software detailed design specifications, volume 1

The detailed design specifications (as built) for the SEPAC Flight Software are defined. The design includes a description of the total software system and of each individual module within the system. The design specifications describe the decomposition of the software system into its major components. The system structure is expressed in the following forms: the control-flow hierarchy of the system, the data-flow structure of the system, the task hierarchy, the memory structure, and the software to hardware configuration mapping. The component design description includes details on the following elements: register conventions, module (subroutines) invocaton, module functions, interrupt servicing, data definitions, and database structure.

Source record↗

The cost of software fault tolerance

The proposed use of software fault tolerance techniques as a means of reducing software costs in avionics and as a means of addressing the issue of system unreliability due to faults in software is examined. A model is developed to provide a view of the relationships among cost, redundancy, and reliability which suggests strategies for software development and maintenance which are not conventional.

Migneault, G. E.↗

Staffing implications of software productivity models

The attributes of software project staffing and productivity implied by equating the effects of two popular software models in a small neighborhood of a given effort-duration point are investigated. The first model presupposes that organizational productivity decreases as a function of the project staff size due to interfacing and intercommunication. The second, the so-called software equation, relates the product size to effort and duration through a power law tradeoff formula. The conclusions that may be reached by assuming that both of these describe project behavior, the former as a global phenomenon and the latter as a localized effect in a small neighborhood of a given effort duration point, are that (1) there is a calculable maximum effective staff level, which, if exceeded, reduces the project production rate, (2) there is a calculable maximum extent to which effort and time may be traded effectively, (3) it becomes ineffective in a practical sense to expend more than an additional 25 to 50% of resources in order to reduce delivery time, and (4) the team production efficiency can be computed directly from the staff level, the slope of the intercommunication loss function, and the ratio of exponents in the software equation.

Tausworthe, R. C.↗

On the engineering of crucial software

The various aspects of the conventional software development cycle are examined. This cycle was the basis of the augmented approach contained in the original grant proposal. This cycle was found inadequate for crucial software development, and the justification for this opinion is presented. Several possible enhancements to the conventional software cycle are discussed. Software fault tolerance, a possible enhancement of major importance, is discussed separately. Formal verification using mathematical proof is considered. Automatic programming is a radical alternative to the conventional cycle and is discussed. Recommendations for a comprehensive approach are presented, and various experiments which could be conducted in AIRLAB are described.

Pratt, T. W.↗