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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
NASA NTRS1977

RINA: An interactive system for the rapid interpretation of NASTRAN results

RINA is a general post-processor system which performs data reduction, post processing and post analysis of NASTRAN results. RINA can be run in either batch or time-sharing mode. The system, which is an expansion of the NASDAT program, performs the following tasks: (1) scan of extreme values for displacements, forces, stresses and margins of safety, (2) computations of envelopes for displacements, forces, stresses and margins of safety, (3) computations of allowables and margins of safety; and (4) generation of NASTRAN tables needed for reanalysis computations. Usage of all these options provides the analyst with an efficient tool for the study and interpretation of NASTRAN analysis results and their presentation for project documentation.

Raibstone, A. I.↗
NASA NTRS1977

Study to investigate and evaluate means of optimizing the Ku-band combined radar/communication functions for the space shuttle

The Ku band radar system on the shuttle orbiter operates in both a search and a tracking mode, and its transmitter and antennas share time with the communication mode in the integrated system. The power allocation properties and the Costa subloop subcarrier tracking performance associated with the baseline digital phase shift implementation of the three channel orbiter Ku band modulator are discussed.

Weber, C. L.↗
NASA NTRS1978

User's guide to SFTRAN/1100

Extensions and improvements were made to SFTRAN, a structured programming language. This language was implemented as a precompiler that translates from SFTRAN to FORTRAN. It was available to batch and conversational users of the UNIVAC 1100 computer system. The SFTRAN language and its use are described. In addition, conversational time-sharing system command subroutines were implemented that eliminated the complications of dealing with extra files and processing steps that the use of a precompiler would otherwise require. These command subroutines are reported, and their use is illustrated by examples.

Ford, W. F.↗
NASA NTRS1977

CTS /Hermes/ - United States experiments and operations summary

The U.S. experiments conducted with the Communications Technology Satellite, a joint Canadian-U.S. venture launched in 1976, are discussed. The 14/12 GHz frequencies employed by the 200-W transmitter on board the satellite provide two-way television and voice communications. Applications of the satellite in the categories of health care, community services and education are considered; experiments have also made use of the special properties of the super-high frequency band (e.g. link characterization and digital communications). Time-sharing of the 14/12 GHz communication between the U.S. and Canada has functioned well.

Donoughe, P. L.↗
NASA NTRS1978

Interactive data line study and experiment

The paper considers the utility of having remote terminals on a Landsat image processing system and the development of efficient data transfer strategies such as data compression. The approach is to link an image processing terminal (located in a mobile van) to a multiuser host computer via the Communications Technology Satellite and a leased phone line. The host computer will share time between the remote state users and local users. The terminal includes a minicomputer, a color video display, and a communications interface, and the user has access to all of the resources of the host facility via the data link. While at present the terminal acts in the display-only mode, the computing capability of the terminal can be varied from display-only up to a stand-alone image processing system. An analysis of trade-offs between data link and remote terminal capacities is described with attention to the evaluation of the system by state users and the selection of a system architecture suitable to unique needs.

Rasmussen, D. N.↗
NASA NTRS1978

Structure and evolution of solar radio bursts at 26.4 MHz

Results are reported for multiple-baseline interferometric measurements of type II, III, IV, and V solar radio bursts at 26.4 MHz. Thirty-two burst events in a two-month period are analyzed by fitting a double-Gaussian two-dimensional source-brightness distribution model to the observed interferometer visibility function. The multibaseline time-sharing interferometer system employed is described in detail, the model-fitting technique is outlined, and values of the model-fit parameters are given for all 32 cases, which include two type II bursts, three type IV bursts, 17 type III bursts, seven type V bursts, and three bursts of type III, V pairs. The temporal evolution of source structure, size, and motion is examined for the different burst types. The core-halo source structure for the type III bursts is interpreted in comparison to two models, one of which assumes scattering and refraction of a point source while the other postulates primarily refraction from an ensemble of sources distributed over a wide sector in solar longitude.

Chen, H. S.-L.↗
NASA NTRS1979

Self-calibrating threshold detector for noisy signals

Single time-shared channel is not seriously affected by temperature and aging. Circuit should also be useful in industrial and consumer equipment. For example, it might be incorporated in telemetry for security systems.

Barnes, J. R.↗
NASA NTRS1978

Apparatus and method for stabilized phase detection for binary signal tracking loops

Apparatus and method is presented for phase detection in binary signal tracking loops wherein two bandpass detectors are alternately interchanged between electrical connection with two local code reference tracking signals in order to cancel any adverse effect of gain imbalance in the bandpass detectors and direct current offset or drift. The detectors are time shared in multiplex fashion between the two local reference signals.

Hopkins, P. M.↗
NASA NTRS1978

Prospects of a mathematical theory of human behavior in complex man-machine systems tasks

A hierarchy of human activities is derived by analyzing automobile driving in general terms. A structural description leads to a block diagram and a time-sharing computer analogy. The range of applicability of existing mathematical models is considered with respect to the hierarchy of human activities in actual complex tasks. Other mathematical tools so far not often applied to man machine systems are also discussed. The mathematical descriptions at least briefly considered here include utility, estimation, control, queueing, and fuzzy set theory as well as artificial intelligence techniques. Some thoughts are given as to how these methods might be integrated and how further work might be pursued.

Johannsen, G.↗
NASA NTRS1977

Multipurpose Panel Display Device Investigation

A multipurpose panel was developed to provide a flexible control and a LED display panel with easily changeable nomenclature for use in applications where panel space is limited, but where a number of similar subsystems must be controlled, or where basic panel nomenclature and functions must be changed rapidly, as in the case of between mission changes of space shuttle payloads. In the first application, panel area limitations are overcome by time sharing a central control panel among several subsystems. In the latter case, entire control panel changes are effected by simply replacing a memory module, thereby reducing the extent of installation and checkout procedures between missions. Several types of control technologies (other than LED's) which show potential in meeting criteria for overcoming limitations of the panel are assessed.

Sliwa, R.↗
NASA NTRS1974

User's instructions for the GE cardiovascular model to simulate LBNP and tilt experiments, with graphic capabilities

The present form of this cardiovascular model simulates both 1-g and zero-g LBNP (lower body negative pressure) experiments and tilt experiments. In addition, the model simulates LBNP experiments at any body angle. The model is currently accessible on the Univac 1110 Time-Shared System in an interactive operational mode. Model output may be in tabular form and/or graphic form. The graphic capabilities are programmed for the Tektronix 4010 graphics terminal and the Univac 1110.

Source record↗
NASA NTRS1974

Modifications to the steady-state 41-node thermoregulatory model including validation of the respiratory and diffusional water loss equations

After the simplified version of the 41-Node Stolwijk Metabolic Man Model was implemented on the Sigma 3 and UNIVAC 1110 computers in batch mode, it became desirable to make certain revisions. First, the availability of time-sharing terminals makes it possible to provide the capability and flexibility of conversational interaction between user and model. Secondly, recent physiological studies show the need to revise certain parameter values contained in the model. Thirdly, it was desired to make quantitative and accurate predictions of evaporative water loss for humans in an orbiting space station. The result of the first phase of this effort are reported.

Source record↗
NASA NTRS1979

ATLAS, an integrated structural analysis and design system. Volume 3: User's manual, input and execution data

The input data and execution control statements for the ATLAS integrated structural analysis and design system are described. It is operational on the Control Data Corporation (CDC) 6600/CYBER computers in a batch mode or in a time-shared mode via interactive graphic or text terminals. ATLAS is a modular system of computer codes with common executive and data base management components. The system provides an extensive set of general-purpose technical programs with analytical capabilities including stiffness, stress, loads, mass, substructuring, strength design, unsteady aerodynamics, vibration, and flutter analyses. The sequence and mode of execution of selected program modules are controlled via a common user-oriented language.

Dreisbach, R. L.↗
NASA NTRS1979

Automating the Analytical Laboratories Section, Lewis Research Center, National Aeronautics and Space Administration: A feasibility study

The feasibility of computerized automation of the Analytical Laboratories Section at NASA's Lewis Research Center was considered. Since that laboratory's duties are not routine, the automation goals were set with that in mind. Four instruments were selected as the most likely automation candidates: an atomic absorption spectrophotometer, an emission spectrometer, an X-ray fluorescence spectrometer, and an X-ray diffraction unit. Two options for computer automation were described: a time-shared central computer and a system with microcomputers for each instrument connected to a central computer. A third option, presented for future planning, expands the microcomputer version. Costs and benefits for each option were considered. It was concluded that the microcomputer version best fits the goals and duties of the laboratory and that such an automted system is needed to meet the laboratory's future requirements.

Boyle, W. G.↗
NASA NTRS1979

Single frequency RF powered ECG telemetry system

It has been demonstrated that a radio frequency magnetic field can be used to power implanted electronic circuitry for short range telemetry to replace batteries. A substantial reduction in implanted volume can be achieved by using only one RF tank circuit for receiving the RF power and transmitting the telemetered information. A single channel telemetry system of this type, using time sharing techniques, was developed and employed to transmit the ECG signal from Rhesus monkeys in primate chairs. The signal from the implant is received during the period when the RF powering radiation is interrupted. The ECG signal is carried by 20-microsec pulse position modulated pulses, referred to the trailing edge of the RF powering pulse. Satisfactory results have been obtained with this single frequency system. The concept and the design presented may be useful for short-range long-term implant telemetry systems.

Ko, W. H.↗
NASA NTRS1979

Tracking and data relay satellite system - NASA's new spacecraft data acquisition system

This paper describes NASA's new spacecraft acquisition system provided by the Tracking and Data Relay Satellite System (TDRSS). Four satellites in geostationary orbit and a ground terminal will provide complete tracking, telemetry, and command service for all of NASA's orbital satellites below a 12,000 km altitude. Western Union will lease the system, operate the ground terminal and provide operational satellite control. NASA's network control center will be the focal point for scheduling user services and controlling the interface between TDRSS and the NASA communications network, project control centers, and data processing. TDRSS single access user spacecraft data systems will be designed for time shared data relay support, and reimbursement policy and rate structure for non-NASA users are being developed.

Schneider, W. C.↗
NASA NTRS1980

Time-shaped RF brazing

One RF generator is controlled from two independent work stations with aid of RF switch and simple control boxes. Brazing may be stopped manually or automatically by external brazing-temperature controller or timer in RF switch housing. Switch is air-operated with water-cooled contacts. If switch loses air pressure, generator stops transmitting power. Time-shared outlet increases utilization and productivity of costly RF generator.

Stein, J. A.↗
NASA NTRS1981

Common data buffer

Time-shared interface speeds data processing in distributed computer network. Two-level high-speed scanning approach routes information to buffer, portion of which is reserved for series of "first-in, first-out" memory stacks. Buffer address structure and memory are protected from noise or failed components by error correcting code. System is applicable to any computer or processing language.

Byrne, F.↗