Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “information quality”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38

Functional states of the operator

A study was made of the changes that occur in the functional state of the operator as he does his job. The functional state of the operator is understood to mean the available characteristics of his functions and qualities which, directly or indirectly, determine how he receives, processes, and reads out information. These characteristics change, depending on many conditions found on the job, and can be higher or lower, than those values which exist in the so-called operator rest state, when the person is doing nothing, but is ready to act. A number of environmental factors, directly or indirectly related to the job, act on the operator controlling a system. Analysis of the causes of changes in the functional state suggests they can be broken down into two main groups: those associated with the physical characteristics of the influencing factors, and those attributable to the informational structure of the signals. There are as well many internal causes, primarily changes in the basic properties of those functions on which operator performance depends for the most part, that affect the functional state.

Medvedev, V. I.↗

Earth Resources Technology Satellite: Cumulative US standard catalog, 23 July 1972 - 23 July 1973. Volume 1: Observation ID listing

Observation identification and coordinate listing are given for ERTS 1 images collected over the continental United States, Alaska, and Hawaii from July 23, 1972 to July 23, 1973. Data format includes the following: (1) the date of catalog listing; (2) the time frame during which the imagery was processed; (3) an assigned observation number; (4) microfilm role and image position on roll; (5) date of observation; (6) longitude and latitude in degrees and minutes at observation center; (7) estimated percent of cloud cover; (8) orbit number; (9) sun elevation and azimuth at observation center; and (10) image quality for both the return beam vidicon and the multispectral band scanner. Availability information for microfilm copies of ERTS imagery is included.

Source record↗

Selected technology for the gas industry

A number of papers were presented at a conference concerned with the application of technical topics from aerospace activities for the gas industry. The following subjects were covered: general future of fossil fuels in America, exploration for fossil and nuclear fuels from orbital altitudes, technology for liquefied gas, safety considerations relative to fires, explosions, and detonations, gas turbomachinery technology, fluid properties, fluid flow, and heat transfer, NASA information and documentation systems, instrumentation and measurement, materials and life prediction, reliability and quality assurance, and advanced energy systems (including synthetic fuels, energy storage, solar energy, and wind energy).

Source record↗

Soil moisture ground truth: Steamboat Springs, Colorado, site and Walden, Colorado, site

Ground-truth data taken at Steamboat Springs and Walden, Colorado in support of the NASA missions in these areas during the period March 8, 1976 through March 11, 1976 was presented. This includes the following information: snow course data for Steamboat Springs and Walden, snow pit and snow quality data for Steamboat Springs, and soil moisture report.

Jones, E. B.↗

Facilities for US radioastronomy

An overview of the radio-astronomy field is given, and prospects ready for construction at NASA are presented. A very-long-baseline array consisting of ten 25 m antennas, with a limiting wavelength of 7 mm and an angular resolution at that wavelength of 2 x 10 to the 4th arcsec is discussed. Eighty percent of the phase information will be obtained by closure around the 36 independent triangles, and high quality aperture-synthesis maps will be produced at all wavelengths. The 25 m telescope will be capable of several applications including the discovery of new molecules in our galaxy (in particular, the envelope of the evolved carbon star IRC + 10216), the detection of CO to distances of perhaps 100 million light years, and the understanding of the events which occur as stars are formed from molecular clouds, and as energy is fed back into the molecular gas by new stars. The submillimeter-wave telescope contains the last atmospheric radio windows where astronomical observations can be made from the earth's surface. The need for funding is stressed.

Thaddeus, P.↗

The display of molecular models with the Ames Interactive Modeling System (AIMS)

A visualization of molecular models can lead to a clearer understanding of the models. Sophisticated graphics devices supported by minicomputers make it possible for the chemist to interact with the display of a very large model, altering its structure. In addition to user interaction, the need arises also for other ways of displaying information. These include the production of viewgraphs, film presentation, as well as publication quality prints of various models. To satisfy these needs, the display capability of the Ames Interactive Modeling System (AIMS) has been enhanced to provide a wide range of graphics and plotting capabilities. Attention is given to an overview of the AIMS system, graphics hardware used by the AIMS display subsystem, a comparison of graphics hardware, the representation of molecular models, graphics software used by the AIMS display subsystem, the display of a model obtained from data stored in molecule data base, a graphics feature for obtaining single frame permanent copy displays, and a feature for producing multiple frame displays.

Egan, J. T.↗

Importance of inlet boundary conditions for numerical simulation of combustor flows

Fluid dynamic computer codes for the mathematical simulation of problems in gas turbine engine combustion systems are required as design and diagnostic tools. To eventually achieve a performance standard with these codes of more than qualitative accuracy it is desirable to use benchmark experiments for validation studies. Typical of the fluid dynamic computer codes being developed for combustor simulations is the TEACH (Teaching Elliptic Axisymmetric Characteristics Heuristically) solution procedure. It is difficult to find suitable experiments which satisfy the present definition of benchmark quality. For the majority of the available experiments there is a lack of information concerning the boundary conditions. A standard TEACH-type numerical technique is applied to a number of test-case experiments. It is found that numerical simulations of gas turbine combustor-relevant flows can be sensitive to the plane at which the calculations start and the spatial distributions of inlet quantities for swirling flows.

Sturgess, G. J.↗

An information theory characterization of radar images and a new definition for radiometric resolution

The noise properties of the radar image formation process are used in the present modeling of a communication channel in which the desired target properties are the information transmitted, and the final image represents the received signal. The average information rate over this communication channel is calculated together with appropriate bounds and approximations, and is found to be small on a per-sample basis. As a result, many samples must be averaged to allow for the discrimination, or classification, of several levels of target reflectivity. These information rate properties are consistent with known results concerning target detection and image quality in speckle, and the rate is applicable to the definition of radar image radiometric resolution. Radiometric resolution is functionally related to the degree of noncoherent averaging performed by the sensor.

Frost, V. S.↗

Cost characteristics of tilt-rotor, conventional air and high speed rail short-haul intercity passenger service

The cost analysis done to support an assessment of the potential for a small tilt-rotor aircraft to operate in short-haul intercity passenger service is described in detail. Anticipated costs of tilt-rotor air service were compared to the costs of two alternatives: conventional air and high speed rail (HSR). Costs were developed for corridor service, varying key market characteristics including distance, passenger volumes, and minimum frequency standards. The resulting cost vs output information can then be used to compare modal costs for essentially identical service quality and passenger volume or for different service levels and volumes for each mode, as appropriate. Extensive sensitivity analyses are performed. The cost-output features of these technologies are compared. Tilt-rotor is very attractive compared to HSR in terms of costs over the entire range of volume. It also has costs not dramatically different from conventional air, but tilt-rotor costs are generally higher. Thus some of its other advantages, such as the VTOL capability, must offset the cost disadvantage for it to be a preferred or competitive mode in any given market. These issues are addressed in the companion report which considers strategies for tilt-rotor development in commercial air service.

Schoendorfer, David L.↗

Integration of the TDWR and LLWAS wind shear detection system

Operational demonstrations of a prototype TDWR/LLWAS (Terminal Doppler Weather Radar/Low Level Wind shear Alarm System) integrated wind shear detection system were conducted. The integration of wind shear detection systems is needed to provide end-users with a single, consensus source of information. A properly implemented integrated system provides wind shear warnings of a higher quality than stand-alone LLWAS or TDWR systems. The algorithmic concept used to generate the TDWR/LLWAS integrated products and several case studies are discussed, indicating the viability and potential of integrated wind shear detection systems. Implications for integrating ground and airborne wind shear detection systems are briefly examined.

Cornman, Larry↗

The role of criteria in design and management of space systems

Explicit requirements and standards arising in connection with space systems management serve as a framework for technical management and furnish legally binding control of development, verification, and operations. As a project develops, additional requirements are derived which are unique to the system in question; these are designated 'derived requirements'. The reliability and cost-effectiveness of a space system are best ensured where a balance has arisen between formal (legally binding) and informal. Attention is presently given to the development of criteria consistent with total quality management.

Blair, J. C.↗

Investigation of cloud/water vapor motion winds from geostationary satellite

This report summarizes the research work accomplished on the NASA grant contract NAG8-892 during 1992. Research goals of this contract are the following: to complete upgrades to the Cooperative Institute for Meteorological Satellite Studies (CIMSS) wind system procedures for assigning heights and incorporating first guess information; to evaluate these modifications using simulated tracer fields; to add an automated quality control system to minimize the need for manual editing, while maintaining product quality; and to benchmark the upgraded algorithm in tests with NMC and/or MSFC. Work progressed on all these tasks and is detailed. This work was done in collaboration with CIMSS NOAA/NESDIS scientists working on the operational winds software, so that NASA funded research can benefit NESDIS operational algorithms.

Source record↗

Conjunctive programming: An interactive approach to software system synthesis

This report introduces a technique of software documentation called conjunctive programming and discusses its role in the development and maintenance of software systems. The report also describes the conjoin tool, an adjunct to assist practitioners. Aimed at supporting software reuse while conforming with conventional development practices, conjunctive programming is defined as the extraction, integration, and embellishment of pertinent information obtained directly from an existing database of software artifacts, such as specifications, source code, configuration data, link-edit scripts, utility files, and other relevant information, into a product that achieves desired levels of detail, content, and production quality. Conjunctive programs typically include automatically generated tables of contents, indexes, cross references, bibliographic citations, tables, and figures (including graphics and illustrations). This report presents an example of conjunctive programming by documenting the use and implementation of the conjoin program.

Tausworthe, Robert C.↗

Boeing Satellite Television Airplane Receiving System (STARS) performance

Boeing Defense and Space Group is developing a Satellite Television Airplane Receiving System (STARS) capable of delivering Direct Broadcast Satellite (DBS) television to an aircraft in-flight. This enables a new service for commercial airplanes that will make use of existing and future DBS systems. The home entertainment satellites, along with STARS, provide a new mobile satellite communication application. This paper will provide a brief background of the antenna issues associated with STARS for commercial airplanes and then describe the innovative Boeing phased-array solution to these problems. The paper then provides a link budget of the STARS using the Hughes DBS as an example, but the system will work with all of the proposed DBS satellites in the 12.2-12.7 GHz band. It concludes with operational performance calculations of the STARS system, supported by measured test data of an operational 16-element subarray. Although this system is being developed for commercial airplanes, it is well suited for a wide variety of mobile military and other commercial communications systems in air, on land and at sea. The applications include sending high quality video for the digital battlefield and large volumes of data on the information superhighway at rates in excess of 350 Mbps.

Vertatschitsch, Edward J.↗

Space Derived Air Monitor

COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.

Source record↗

Tactical Defenses Against Systematic Variation in Wind Tunnel Testing

This paper examines the role of unexplained systematic variation on the reproducibility of wind tunnel test results. Sample means and variances estimated in the presence of systematic variations are shown to be susceptible to bias errors that are generally non-reproducible functions of those variations. Unless certain precautions are taken to defend against the effects of systematic variation, it is shown that experimental results can be difficult to duplicate and of dubious value for predicting system response with the highest precision or accuracy that could otherwise be achieved. Results are reported from an experiment designed to estimate how frequently systematic variations are in play in a representative wind tunnel experiment. These results suggest that significant systematic variation occurs frequently enough to cast doubts on the common assumption that sample observations can be reliably assumed to be independent. The consequences of ignoring correlation among observations induced by systematic variation are considered in some detail. Experimental tactics are described that defend against systematic variation. The effectiveness of these tactics is illustrated through computational experiments and real wind tunnel experimental results. Some tutorial information describes how to analyze experimental results that have been obtained using such quality assurance tactics.

DeLoach, Richard↗

Anisotropic Solution Adaptive Unstructured Grid Generation Using AFLR

An existing volume grid generation procedure, AFLR3, was successfully modified to generate anisotropic tetrahedral elements using a directional metric transformation defined at source nodes. The procedure can be coupled with a solver and an error estimator as part of an overall anisotropic solution adaptation methodology. It is suitable for use with an error estimator based on an adjoint, optimization, sensitivity derivative, or related approach. This offers many advantages, including more efficient point placement along with robust and efficient error estimation. It also serves as a framework for true grid optimization wherein error estimation and computational resources can be used as cost functions to determine the optimal point distribution. Within AFLR3 the metric transformation is implemented using a set of transformation vectors and associated aspect ratios. The modified overall procedure is presented along with details of the anisotropic transformation implementation. Multiple two-and three-dimensional examples are also presented that demonstrate the capability of the modified AFLR procedure to generate anisotropic elements using a set of source nodes with anisotropic transformation metrics. The example cases presented use moderate levels of anisotropy and result in usable element quality. Future testing with various flow solvers and methods for obtaining transformation metric information is needed to determine practical limits and evaluate the efficacy of the overall approach.

Marcum, David L.↗

NASA Tech Briefs, February 2001

The topics include: 1) Application Briefs; 2) National Design Engineering Show Preview; 3) Marketing Inventions to Increase Income; 4) A Personal-Computer-Based Physiological Training System; 5) Reconfigurable Arrays of Transistors for Evolvable Hardware; 6) Active Tactile Display Device for Reading by a Blind Person; 7) Program Automates Management of IBM VM Computer Systems; 8) System for Monitoring the Environment of a Spacecraft Launch; 9) Measurement of Stresses and Strains in Muscles and Tendons; 10) Optical Measurement of Temperatures in Muscles and Tendons; 11) Small Low-Temperature Thermometer With Nanokelvin Resolution; 12) Heterodyne Interferometer With Phase-Modulated Carrier; 13) Rechargeable Batteries Based on Intercalation in Graphite; 14) Signal Processor for Doppler Measurements in Icing Research; 15) Model Optimizes Drying of Wet Sheets; 16) High-Performance POSS-Modified Polymeric Composites; 17) Model Simulates Semi-Solid Material Processing; 18) Modular Cryogenic Insulation; 19) Passive Venting for Alleviating Helicopter Tail-Boom Loads; 20) Computer Program Predicts Rocket Noise; 21) Process for Polishing Bare Aluminum to High Optical Quality; 22) External Adhesive Pressure-Wall Patch; 23) Java Implementation of Information-Sharing Protocol; 24) Electronic Bulletin Board Publishes Schedules in Real Time; 25) Apparatus Would Extract Water From the Martian Atmosphere; 26) Review of Research on Supercritical vs Subcritical Fluids; 27) Hybrid Regenerative Water-Recycling System; 28) Study of Fusion-Driven Plasma Thruster With Magnetic Nozzle; 29) Liquid/Vapor-Hydrazine Thruster Would Produce Small Impulses; and 30) Thruster Based on Sublimation of Solid Hydrazine

Source record↗