Search NASA⌕ Search

SEARCH · Search NASA

Results for “STI”

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 181 records · Page 10

Molecular Regulatory Mechanisms Drive Emergent Pathogenetic Properties of Neisseria gonorrhoeae

Neisseria gonorrhoeae is the causative agent of the sexually transmitted infection (STI) gonorrhea, with an estimated 87 million annual cases worldwide. N. gonorrhoeae predominantly colonizes the male and female genital tract (FGT). In the FGT, N. gonorrhoeae confronts fluctuating levels of nutrients and oxidative and non-oxidative antimicrobial defenses of the immune system, as well as the resident microbiome. One mechanism utilized by N. gonorrhoeae to adapt to this dynamic FGT niche is to modulate gene expression primarily through DNA-binding transcriptional regulators. Here, we describe the major N. gonorrhoeae transcriptional regulators, genes under their control, and how these regulatory processes lead to pathogenic properties of N. gonorrhoeae during natural infection. We also discuss the current knowledge of the structure, function, and diversity of the FGT microbiome and its influence on gonococcal survival and transcriptional responses orchestrated by its DNA-binding regulators. We conclude with recent multi-omics data and modeling tools and their application to FGT microbiome dynamics. Understanding the strategies utilized by N. gonorrhoeae to regulate gene expression and their impact on the emergent characteristics of this pathogen during infection has the potential to identify new effective strategies to both treat and prevent gonorrhea.

59 BASIC BIOLOGICAL SCIENCES↗

The measurement of driver describing functions in simulated steering control tasks

Measurements of driver describing functions in steering control tasks have been made using a driving simulator. The task was to regulate against a random crosswind gust input on a straight roadway, in order to stay in the center of the lane. Although driving is a multiloop task in general, the forcing function and situation were configured so that an inner-loop visual cue feedback of heading angle of heading rate would dominate, and the driver's response was interpreted to be primarily single-loop. The driver describing functions were measured using an STI describing function analyzer. Three replications for each subject showed good repeatability within a subject. There were some intersubject differences as expected, but the crossover frequencies, effective time delays, and stability margins were generally consistent with the prior data and models for similar manual control tasks. The results further confirm the feasibility of measuring human operator response properties in nominal control tasks with full (real-world) visual field displays.

Weir, D. H.↗

Further examination of pilot instrument scanning data and development of a new link value estimator

Pilot instrument scanning data collected during simulated transport instrument landing approaches is examined. Deterministic features of random pilot instrument scanning behavior are confirmed to be: transitions in point of eye fixation which originate and terminate on the same instrument are rare; and transitions in point of eye fixation which originate on one secondary instrument and terminate on another secondary instrument are rare. Link value estimators are developed using statistics and these experimental facts. The result has a special significance when there is but a single primary instrument, a flight director. The result is used to simplify the iterative computational procedure of STI's display theory to a non-iterative procedure for the flight director case.

Hofmann, L. G.↗

The role of NASA for aerospace information

The NASA Scientific and Technical Information Program operations are performed by two contractor operated facilities. The NASA STI Facility, located near Baltimore, Maryland, employs about 210 people who process report literature, operate the computer complex, and provide support for software maintenance and developments. A second contractor, the Technical Information Services of the American Institute of Aeronautics and Astronautics, employs approximately 80 people in New York City and processes the open literature such as journals, magazines, and books. Features of these programs include online access via RECON, announcement services, and international document exchange.

Chandler, G. P., Jr.↗

Marketing information: The technical report as product

Technical reports constitute a product, the primary means for communicating the results of research to the user. The Langley scientific and technical information (STI) review and evaluation project undertook a review of the technical report as an effective product for information communication. Style manuals describing theory and practice in technical report preparation; publication manuals covering such factors as design, layout, and type style; and copies of technical reports were obtained from industrial, academic, governmental, and research organizations. Based on an analysis of this material, criteria will be established for the report components, for the relationship of the components within the report context, and for the overall report organization. The criteria will be used as bench marks and compared with the publication standards currently used to prepare NASA technical reports.

Stoher, F. F.↗

Architecture and performance of a real time differential GPS ground station

The NAVSTAR Global Positioning System (GPS) is a satellite based navigation system that can be operated in a differential mode. The basic concept of differential GPS is to have a local ground station at a known location. The ground station continuously determines bias corrections based on the received satellite signals and transmits these corrections to local users. This allows the user to improve significantly their estimate of position. The architecture of a real time differential GPS ground station based on two STI (Stanford Telecommunications, Inc.) single-channel GPS receivers is presented. Receiver requirements are described, together with the receiver architectures. Real time operation results are presented for recent data collected from six satellites.

Turner, R. N.↗

Description of graphics translation software between Intergraph and Tektronix systems

The requirement for Marshall Space Flight Center's Photo Analysis to use existing 3-D Intergraph graphic files on an existing Tektronix 4129 3-D graphics workstation and the unavailability of an off-the-shelf Intergraph to Tektronix translator required the development of such a translater. Using the output of Intergraph's standard interchange format converter, the 3-D graphic information of Intergraph's files are reformatted and compressed. The 3-D image is reconstructed using Tektronix's software terminal interface graphic library (STI).

Rieckhoff, Tom↗

Government Information Quarterly. Volume 7, no. 2: National Aeronautics and Space Administration Scientific and Technical Information Programs. Special issue

NASA scientific and technical information (STI) programs are discussed. Topics include management of information in a research and development agency, the new space and Earth science information systems at NASA's archive, scientific and technical information management, and technology transfer of NASA aerospace technology to other industries.

Hernon, Peter↗

The NASA/DOD aerospace knowledge diffusion research project: A research agenda

The project has both immediate and long term purposes. In the first instance it provides a practical and pragmatic basis for understanding how the results of NASA/DoD research diffuse into the aerospace R and D process. Over the long term it provides an empirical basis for understanding the aerospace knowledge diffusion process itself, and its implications at the individual, organizational, national, and international levels. The project is studying the major barriers to effective knowledge diffusion. This project will provide descriptive and analytical data regarding the flow of scientific and technical information (STI). It will examine both channels used to communicate information and the social system of the aerospace knowledge diffusion process.

Pinelli, Thomas E.↗

NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 4: Summary report to phase 1 respondents

Phase 1 of a 4 part study was undertaken studying the use of scientific and technical information (STI) by U.S. aerospace engineers and scientists. Specific attention was paid to institutional and socioeconomic variables and to the step-by-step process of information gathering used by the respondents. Data were collected by means of three self administered mail-back questionnaires. The approximately 34,000 members of the American Institute of Aeronautics and Astronautics (AIAA) served as the study population. More than 65 percent of the randomly selected respondents returned the questionnaires in each of the three groups. Respondents relied more heavily upon informal sources of information than formal sources and turned to librarians and other technical information specialists only when they did not obtain results via informal means or their own formal searches.

Pinelli, Thomas E.↗

[NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 5:] Summary report to phase 1 respondents including frequency distributions

Phase 1 of a four part study was undertaken to investigate the use of scientific and technical information (STI) by U.S. aerospace engineers and scientists. Specific attention was paid to institutional and sociometric variables and to the step-by-step process of information gathering used by the respondents. Data were collected by means of three self-administered mail-back questionnaires. The approximately 34,000 members of the American Institute of Aeronautics and Astronautics served as the study population. More than 65 percent of the randomly selected respondants returned the questionnaires in each of the three groups. Respondants relied more heavily on informal sources of information than formal sources and turned to librarians and other technical information specialists only when they did not obtain results via informal means or their own formal searches. The report includes frequency distributions for the questions.

Pinelli, Thomas E.↗

NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 7:Summary report to phase 2 respondents including frequency distributions

Phase 2 of the four phase NASA/DoD Aerospace Knowledge Diffusion Research Project was undertaken to study the transfer of scientific and technical information (STI) from government to the aerospace industry and the role of librarians and technical information specialists in the transfer process. Data was collected through a self-administered mailback questionnaire. Libraries identified as holding substantial aerospace or aeronautical technical report collections were selected to receive the questionnaires. Within each library, the person responsible for the technical report was requested to answer the questionnaire. Questionnaires were returned from approx. 68 pct. of the libraries. The respondents indicated that scientists and engineer are not aware of the services available from libraries/technical information centers and that scientists and engineers also under-utilized their services. The respondents also indicated they should be more involved in the process.

Pinelli, Thomas E.↗

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 6: Aerospace knowledge diffusion in the academic community: A report of phase 3 activities of the NASA/DOD Aerospace Knowledge Diffusion Research Project

Descriptive and analytical data regarding the flow of aerospace-based scientific and technical information (STI) in the academic community are presented. An overview is provided of the Federal Aerospace Knowledge Diffusion Research Project, illustrating a five-year program on aerospace knowledge diffusion. Preliminary results are presented of the project's research concerning the information-seeking habits, practices, and attitudes of U.S. aerospace engineering and science students and faculty. The type and amount of education and training in the use of information sources are examined. The use and importance ascribed to various information products by U.S. aerospace faculty and students including computer and other information technology is assessed. An evaluation of NASA technical reports is presented and it is concluded that NASA technical reports are rated high in terms of quality and comprehensiveness, citing Engineering Index and IAA as the most frequently used materials by faculty and students.

Pinelli, Thomas E.↗

CENDI - A strategic interagency alliance in the 1990s

The goals, functions, and accomplishments of the CENDI Group, a government interagency cooperative organization formed to improve federal research and development productivity and R&D information management systems through information exchange, are briefly reviewed. The five member agencies are the Departments of Commerce, Energy, Defense, and Health and Human Services, and NASA. CENDI provides a means for its members to share technologies, resources, ideas, information, management activities, and standards. The top priorities of CENDI are: work with R&D managers to improve productivity; provide technical data and information to all users; improve the effectiveness and efficiency of all CENDI agency operations; and familiarize R&D managers and policy makers with the value of STI.

Caponio, Joseph↗

Software technology insertion: A study of success factors

Managing software development in large organizations has become increasingly difficult due to increasing technical complexity, stricter government standards, a shortage of experienced software engineers, competitive pressure for improved productivity and quality, the need to co-develop hardware and software together, and the rapid changes in both hardware and software technology. The 'software factory' approach to software development minimizes risks while maximizing productivity and quality through standardization, automation, and training. However, in practice, this approach is relatively inflexible when adopting new software technologies. The methods that a large multi-project software engineering organization can use to increase the likelihood of successful software technology insertion (STI), especially in a standardized engineering environment, are described.

Lydon, Tom↗

Unification: An international aerospace information issue

Science and technology projects are becoming more and more international and interdisciplinary. Other parts of the world, notably Europe, are increasingly powerful players in the aerospace business. This change has led to the development of various aerospace information initiatives in other countries. With scarce resources in all areas of government and industry, the NASA STI Program is reviewing its current acquisition and exchange practices and policies to factor in the changing requirements and new opportunities within the international community. Current NASA goals and activities are reviewed with a view toward developing a scenario for establishing an international aerospace data base, maintaining compatibility among national aerospace information systems, eliminating duplication of effort, and sharing resources through international cooperation wherever possible.

Cotter, Gladys A.↗

Unification: An international aerospace information opportunity

Science and technology projects are becoming more and more international and interdisciplinary. Other parts of the world, notably Europe, are increasingly powerful players in the aerospace industry. This change has led to the development of various aerospace information initiatives in other countries. With scarce resources in all areas of government and industry, the NASA STI Program is reviewing its current acquisition and exchange practices and policies to factor in the changing requirements and new opportunities within the international community. Current NASA goals and activities are reviewed with a new view toward developing a scenario for establishing an international aerospace database, maintaining compatibility among national aerospace information systems, eliminating duplication of effort, and sharing resources through international cooperation wherever possible.

Cotter, Gladys A.↗