126,308 research outputs found

    Coordination approaches and systems - part I : a strategic perspective

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    This is the first part of a two-part paper presenting a fundamental review and summary of research of design coordination and cooperation technologies. The theme of this review is aimed at the research conducted within the decision management aspect of design coordination. The focus is therefore on the strategies involved in making decisions and how these strategies are used to satisfy design requirements. The paper reviews research within collaborative and coordinated design, project and workflow management, and, task and organization models. The research reviewed has attempted to identify fundamental coordination mechanisms from different domains, however it is concluded that domain independent mechanisms need to be augmented with domain specific mechanisms to facilitate coordination. Part II is a review of design coordination from an operational perspective

    Making intelligent systems team players: Case studies and design issues. Volume 1: Human-computer interaction design

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    Initial results are reported from a multi-year, interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. The objective is to achieve more effective human-computer interaction (HCI) for systems with real time fault management capabilities. Intelligent fault management systems within the NASA were evaluated for insight into the design of systems with complex HCI. Preliminary results include: (1) a description of real time fault management in aerospace domains; (2) recommendations and examples for improving intelligent systems design and user interface design; (3) identification of issues requiring further research; and (4) recommendations for a development methodology integrating HCI design into intelligent system design

    Development and Psychometric Properties of A Screening Tool for Assessing Developmental Coordination Disorder in Adults

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    Background: Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder affecting motor coordination. Evidence suggests this disorder persists into adulthood and may be associated with biomechanical dysfunction and pain. We report on the development and initial validation of a questionnaire to assess for DCD in adults. Methods: An initial item pool (13 items) was derived from the American Psychiatric Association criteria and World Health Organisation definition for DCD. An expert panel assessed face and content validity which led to a 9-item Functional Difficulties Questionnaire (FDQ-9) with possible scores ranging from 9-36 (higher scores indicating greater functional difficulties). The FDQ-9 was piloted on individuals recruited from convenience samples. The underlying factor structure and aspects of reliability, validity and accuracy were tested. The Receiver Operating Characteristic Curve was employed to evaluate the diagnostic accuracy of the test using self-reported dyspraxia as the reference standard. Results: Principal Axis Factoring yielded a two factor solution relating to gross and fine motor skills; for conceptual parsimony these were combined. Internal reliability was high (0.81), the mean inter-item correlation was 0.51 and preliminary findings suggested satisfactory construct validity. The Area under the Curve was 0.918 [95% CI 0.84-1.00] indicating a diagnostic test with high accuracy. A cut-off score was established with a sensitivity and specificity of 86% [95% CI 78%-89%] and 81% [95 % CI 73%-89%] respectively. Test-retest reliability was good (ICC 0.96 [95% CI 0.92 to 0.98]. Conclusion: The psychometric properties of the FDQ-9 appear promising. Work is required to conduct further psychometric evaluations on new samples and apply the scale to clinical practice

    Data optimizations for constraint automata

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    Constraint automata (CA) constitute a coordination model based on finite automata on infinite words. Originally introduced for modeling of coordinators, an interesting new application of CAs is implementing coordinators (i.e., compiling CAs into executable code). Such an approach guarantees correctness-by-construction and can even yield code that outperforms hand-crafted code. The extent to which these two potential advantages materialize depends on the smartness of CA-compilers and the existence of proofs of their correctness. Every transition in a CA is labeled by a "data constraint" that specifies an atomic data-flow between coordinated processes as a first-order formula. At run-time, compiler-generated code must handle data constraints as efficiently as possible. In this paper, we present, and prove the correctness of two optimization techniques for CA-compilers related to handling of data constraints: a reduction to eliminate redundant variables and a translation from (declarative) data constraints to (imperative) data commands expressed in a small sequential language. Through experiments, we show that these optimization techniques can have a positive impact on performance of generated executable code

    AUTOPLAN: A PC-based automated mission planning tool

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    A PC-based automated mission and resource planning tool, AUTOPLAN, is described, with application to small-scale planning and scheduling systems in the Space Station program. The input is a proposed mission profile, including mission duration, number of allowable slip periods, and requirement profiles for one or more resources as a function of time. A corresponding availability profile is also entered for each resource over the whole time interval under study. AUTOPLAN determines all integrated schedules which do not require more than the available resources

    Space shuttle propulsion systems on-board checkout and monitoring system development study. Volume 1 - Summary Final report

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    Development of onboard checkout equipment and performance monitoring capability for space shuttles - Vol.

    Integrated control and health management. Orbit transfer rocket engine technology program

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    To insure controllability of the baseline design for a 7500 pound thrust, 10:1 throttleable, dual expanded cycle, Hydrogen-Oxygen, orbit transfer rocket engine, an Integrated Controls and Health Monitoring concept was developed. This included: (1) Dynamic engine simulations using a TUTSIM derived computer code; (2) analysis of various control methods; (3) Failure Modes Analysis to identify critical sensors; (4) Survey of applicable sensors technology; and, (5) Study of Health Monitoring philosophies. The engine design was found to be controllable over the full throttling range by using 13 valves, including an oxygen turbine bypass valve to control mixture ratio, and a hydrogen turbine bypass valve, used in conjunction with the oxygen bypass to control thrust. Classic feedback control methods are proposed along with specific requirements for valves, sensors, and the controller. Expanding on the control system, a Health Monitoring system is proposed including suggested computing methods and the following recommended sensors: (1) Fiber optic and silicon bearing deflectometers; (2) Capacitive shaft displacement sensors; and (3) Hot spot thermocouple arrays. Further work is needed to refine and verify the dynamic simulations and control algorithms, to advance sensor capabilities, and to develop the Health Monitoring computational methods

    Effectiveness of lending for vocational education and training: lessons from World Bank experience

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    This paper reviews the Bank involvement in the vocational education and training (VET) sub-sector in the 1990s. The paper aims to do just that, by mainly seeking answers to the following questions: 1) How has the Bank performed in its lending services to its clients in VET? 2) How have VET projects performed in terms of meeting stated objectives? 3) What factors led to the success, or failure of Bank operations? Based on what has been learned, the paper provides suggestions about how the performance of future VET interventions can be improved. This review concerns itself primarily with implementation performance, and proposes measures to improve project outcomes.ICT Policy and Strategies,Health Economics&Finance,Health Monitoring&Evaluation,Teaching and Learning,Banks&Banking Reform

    F-8C adaptive flight control extensions

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    An adaptive concept which combines gain-scheduled control laws with explicit maximum likelihood estimation (MLE) identification to provide the scheduling values is described. The MLE algorithm was improved by incorporating attitude data, estimating gust statistics for setting filter gains, and improving parameter tracking during changing flight conditions. A lateral MLE algorithm was designed to improve true air speed and angle of attack estimates during lateral maneuvers. Relationships between the pitch axis sensors inherent in the MLE design were examined and used for sensor failure detection. Design details and simulation performance are presented for each of the three areas investigated

    The Design and Implementation of a PCIe-based LESS Label Switch

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    With the explosion of the Internet of Things, the number of smart, embedded devices has grown exponentially in the last decade, with growth projected at a commiserate rate. These devices create strain on the existing infrastructure of the Internet, creating challenges with scalability of routing tables and reliability of packet delivery. Various schemes based on Location-Based Forwarding and ID-based routing have been proposed to solve the aforementioned problems, but thus far, no solution has completely been achieved. This thesis seeks to improve current proposed LORIF routers by designing, implementing, and testing and a PCIe-based LESS switch to process unrouteable packets under the current LESS forwarding engine
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