8,233 research outputs found

    Avionics test bed development plan

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    A development plan for a proposed avionics test bed facility for the early investigation and evaluation of new concepts for the control of large space structures, orbiter attached flex body experiments, and orbiter enhancements is presented. A distributed data processing facility that utilizes the current laboratory resources for the test bed development is outlined. Future studies required for implementation, the management system for project control, and the baseline system configuration are defined. A background analysis of the specific hardware system for the preliminary baseline avionics test bed system is included

    Intel's XL Permit: A Framework for Evaluation

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    The paper develops a framework to evaluate permits granted to firms under the Environmental Protection Agency's Project XL � with emphasis on the novel air permit granted to the Intel Corporation. We describe the permit, the process that created it, and the types of costs and benefits likely to arise from this type of "facility-specific" regulatory arrangement. Among other things, the paper describes the permit's impact on environmental quality, production costs, transaction costs, and Intel's strategic market position. The paper also considers how an estimate of the costs and benefits � both to Intel and society � might be estimated. While facility-specific regulation typically conjures images of production cost savings as processes are re-engineered and low-cost abatement strategies pursued, the Intel case highlights perhaps a more important source of benefit: flexibility in the form of streamlined permitting. Flexibility in this form allows for accelerated product introductions, with potentially significant benefits to the firm and possibly to society.

    Numerical Aerodynamic Simulation (NAS)

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    The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified

    Progress on advanced dc and ac induction drives for electric vehicles

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    Progress is reported in the development of complete electric vehicle propulsion systems, and the results of tests on the Road Load Simulator of two such systems representative of advanced dc and ac drive technology are presented. One is the system used in the DOE's ETV-1 integrated test vehicle which consists of a shunt wound dc traction motor under microprocessor control using a transistorized controller. The motor drives the vehicle through a fixed ratio transmission. The second system uses an ac induction motor controlled by transistorized pulse width modulated inverter which drives through a two speed automatically shifted transmission. The inverter and transmission both operate under the control of a microprocessor. The characteristics of these systems are also compared with the propulsion system technology available in vehicles being manufactured at the inception of the DOE program and with an advanced, highly integrated propulsion system upon which technology development was recently initiated

    Autonomous spacecraft maintenance study group

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    A plan to incorporate autonomous spacecraft maintenance (ASM) capabilities into Air Force spacecraft by 1989 is outlined. It includes the successful operation of the spacecraft without ground operator intervention for extended periods of time. Mechanisms, along with a fault tolerant data processing system (including a nonvolatile backup memory) and an autonomous navigation capability, are needed to replace the routine servicing that is presently performed by the ground system. The state of the art fault handling capabilities of various spacecraft and computers are described, and a set conceptual design requirements needed to achieve ASM is established. Implementations for near term technology development needed for an ASM proof of concept demonstration by 1985, and a research agenda addressing long range academic research for an advanced ASM system for 1990s are established

    Test status and experience with the 7.5 megawatt Mod-2 wind turbine cluster

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    The Mod-2 wind turbine cluster is described. The site preparation and construction activities are discussed, and preliminary test results, status, and plans are presented

    Security Evaluation of Cyber-Physical Systems in Society- Critical Internet of Things

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    In this paper, we present evaluation of security awareness of developers and users of cyber-physical systems. Our study includes interviews, workshops, surveys and one practical evaluation. We conducted 15 interviews and conducted survey with 55 respondents coming primarily from industry. Furthermore, we performed practical evaluation of current state of practice for a society-critical application, a commercial vehicle, and reconfirmed our findings discussing an attack vector for an off-line societycritical facility. More work is necessary to increase usage of security strategies, available methods, processes and standards. The security information, currently often insufficient, should be provided in the user manuals of products and services to protect system users. We confirmed it lately when we conducted an additional survey of users, with users feeling as left out in their quest for own security and privacy. Finally, hardware-related security questions begin to come up on the agenda, with a general increase of interest and awareness of hardware contribution to the overall cyber-physical security. At the end of this paper we discuss possible countermeasures for dealing with threats in infrastructures, highlighting the role of authorities in this quest

    A rapid prototyping/artificial intelligence approach to space station-era information management and access

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    Applications of rapid prototyping and Artificial Intelligence techniques to problems associated with Space Station-era information management systems are described. In particular, the work is centered on issues related to: (1) intelligent man-machine interfaces applied to scientific data user support, and (2) the requirement that intelligent information management systems (IIMS) be able to efficiently process metadata updates concerning types of data handled. The advanced IIMS represents functional capabilities driven almost entirely by the needs of potential users. Space Station-era scientific data projected to be generated is likely to be significantly greater than data currently processed and analyzed. Information about scientific data must be presented clearly, concisely, and with support features to allow users at all levels of expertise efficient and cost-effective data access. Additionally, mechanisms for allowing more efficient IIMS metadata update processes must be addressed. The work reported covers the following IIMS design aspects: IIMS data and metadata modeling, including the automatic updating of IIMS-contained metadata, IIMS user-system interface considerations, including significant problems associated with remote access, user profiles, and on-line tutorial capabilities, and development of an IIMS query and browse facility, including the capability to deal with spatial information. A working prototype has been developed and is being enhanced
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