222 research outputs found

    On the feasibility of real-time prediction of aircraft carrier motion at sea

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    The ability to predict the aircraft carrier's motion over an interval of several seconds within reasonable error bounds may allow an improvement in touchdown dispersion and a more certain value for ramp clearance due to a smoother aircraft trajectory. Also, improved information to the landing signal officer should decrease the number of waveoffs substantially. It is quantitatively shown that, based on the power density spectrum data for pitch and heave measured for various ships and sea conditions, the motion can be predicted well for up to 15 seconds. The zero crossover times for both pitch and heave motions can be predicted with impressive accuracy. The predictor was designed on the basis of Kalman's optimum filtering theory for the discrete time case, adapted for real-time digital computer operation

    Global differential geometry: An introduction for control engineers

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    The basic concepts and terminology of modern global differential geometry are discussed as an introduction to the Lie theory of differential equations and to the role of Grassmannians in control systems analysis. To reach these topics, the fundamental notions of manifolds, tangent spaces, vector fields, and Lie algebras are discussed and exemplified. An appendix reviews such concepts needed for vector calculus as open and closed sets, compactness, continuity, and derivative. Although the content is mathematical, this is not a mathematical treatise but rather a text for engineers to understand geometric and nonlinear control

    An analog computer study of the effectiveness of interceptor commands derived from a prediction equation of second order

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    Analog computer study of effectiveness of interceptor commands derived from prediction equation of second orde

    Large scale dynamic systems

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    Classes of large scale dynamic systems were discussed in the context of modern control theory. Specific examples discussed were in the technical fields of aeronautics, water resources and electric power

    Simple processors of star tracker commands for stabilizing an inertially oriented satellite

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    Simple processors of star tracker commands for stabilizing inertially oriented satellit

    Exploring qualitative comparative analysis in IS Research

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    Qualitative Comparative Analysis (QCA) has been proposed as a promising qualitative data analysis strategy to study complex problems. QCA provides multiple conjunctural causation that can address generalizability concerns associated with case study research within the IS and other social science disciplines. However, there are not many studies that offer guidelines on how to effectively apply this methodology to IS research. This paper outlines a set of methodological principles for using QCA. An illustrative example of case studies of collaborative networks is discussed to demonstrate the application of QCA
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