26 research outputs found

    Using Shared Models of Activity for Coalition Task-Driven Cooperation

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    Automating Program Verification and Repair Using Invariant Analysis and Test Input Generation

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    Software bugs are a persistent feature of daily life---crashing web browsers, allowing cyberattacks, and distorting the results of scientific computations. One approach to improving software uses program invariants---mathematical descriptions of program behaviors---to verify code and detect bugs. Current invariant generation techniques lack support for complex yet important forms of invariants, such as general polynomial relations and properties of arrays. As a result, we lack the ability to conduct precise analysis of programs that use this common data structure. This dissertation presents DIG, a static and dynamic analysis framework for discovering several useful classes of program invariants, including (i) nonlinear polynomial relations, which are fundamental to many scientific applications; disjunctive invariants, (ii) which express branching behaviors in programs; and (iii) properties about multidimensional arrays, which appear in many practical applications. We describe theoretical and empirical results showing that DIG can efficiently and accurately find many important invariants in real-world uses, e.g., polynomial properties in numerical algorithms and array relations in a full AES encryption implementation. Automatic program verification and synthesis are long-standing problems in computer science. However, there has been a lot of work on program verification and less so on program synthesis. Consequently, important synthesis tasks, e.g., generating program repairs, remain difficult and time-consuming. This dissertation proves that certain formulations of verification and synthesis are equivalent, allowing for direct applications of techniques and tools between these two research areas. Based on these ideas, we develop CETI, a tool that leverages existing verification techniques and tools for automatic program repair. Experimental results show that CETI can have higher success rates than many other standard program repair methods

    Management: A continuing bibliography with indexes

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    This bibliography lists 551 reports, articles, and other documents introduced into NASA scientific and technical information system in 1980

    Management. A continuing bibliography with indexes

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    This bibliography cites 604 reports, articles, and other documents introduced into the NASA scientific and technical information system in 1979 covering the management of research and development, contracts, production, logistics, personnel, safety, reliability and quality control. Program, project, and systems management; management policy, philosophy, tools, and techniques; decision making processes for managers; technology assessment; management of urban problems; and information for managers on Federal resources, expenditures, financing, and budgeting are also covered. Abstracts are provided as well as subject, personal author, and corporate source indexes

    Seventh Annual Workshop on Space Operations Applications and Research (SOAR 1993), volume 1

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    This document contains papers presented at the Space Operations, Applications and Research Symposium (SOAR) Symposium hosted by NASA/Johnson Space Center (JSC) on August 3-5, 1993, and held at JSC Gilruth Recreation Center. SOAR included NASA and USAF programmatic overview, plenary session, panel discussions, panel sessions, and exhibits. It invited technical papers in support of U.S. Army, U.S. Navy, Department of Energy, NASA, and USAF programs in the following areas: robotics and telepresence, automation and intelligent systems, human factors, life support, and space maintenance and servicing. SOAR was concerned with Government-sponsored research and development relevant to aerospace operations. More than 100 technical papers, 17 exhibits, a plenary session, several panel discussions, and several keynote speeches were included in SOAR '93

    Technical Workshop: Advanced Helicopter Cockpit Design

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    Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration

    Design methodology and simulation of a fleet management system for an advanced helicopter platform

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    This research is part of a major helicopter acquisition and upgrade program of the Australian Defence Forces (ADF) under a 20+ year strategic plan. The ‘Air 9000’ program aims to rationalise the number of helicopter types operated, simplify operational requirements and reduce through-life-support costs. This research program developed and modelled a Fleet Management System (FMS) for the newly acquired Multi-Role Helicopter-90 (MRH-90 / NHI NH-90) platform. It assessed current practices in aerospace technology management of civil and military aircraft fleets, and established requirements of civil & military rotary-wing platforms for the development of a fleet management methodology for the MRH-90 platform. A novel approach was adopted by applying systems engineering principles to design the FMS. The systems engineering approach enabled identification and implementation of the additional rotary-wing design parameters, required for system adaptability to future network-centric military & civil operational environments from a life-cycle perspective. This approach has resulted in the development and implementation of an adaptable prototype FMS software with integrated fleet management capabilities. Subsequent simulation & validation demonstrated significant enhancements in operational effectiveness over state-of-the art rotary-wing fleet management practices, by holistically and systematically addressing the present and future system needs of helicopter life-cycle management

    Management. A continuing bibliography for NASA managers, with indexes

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    This bibliography lists 594 reports, articles and other documents introduced into the NASA scientific and technical information system in 1983

    Third CLIPS Conference Proceedings, volume 2

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    Expert systems are computer programs which emulate human expertise in well defined problem domains. The C Language Integrated Production System (CLIPS) is an expert system building tool, developed at the Johnson Space Center, which provides a complete environment for the development and delivery of rule and/or object based expert systems. CLIPS was specifically designed to provide a low cost option for developing and deploying expert system applications across a wide range of hardware platforms. The development of CLIPS has helped to improve the ability to deliver expert system technology throughout the public and private sectors for a wide range of applications and diverse computing environments. The Third Conference on CLIPS provided a forum for CLIPS users to present and discuss papers relating to CLIPS applications, uses, and extensions
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