17,613 research outputs found

    Digital spectral analysis of bistatic-radar echoes from Explorer 35

    Get PDF
    Bistatic radar echoes from Explorer 35 using 150 foot dish antenn

    The bistatic continuous-wave radar method for the study of planetary surfaces Scientific report no. 13

    Get PDF
    Bistatic continuous-wave radar for mapping surface of planet

    Definition phase of Grand Tour missions/radio science investigations study for outer planets missions

    Get PDF
    Scientific instrumentation for satellite communication and radio tracking systems in the outer planet exploration mission is discussed. Mission planning considers observations of planetary and satellite-masses, -atmospheres, -magnetic fields, -surfaces, -gravitational fields, solar wind composition, planetary radio emissions, and tests of general relativity in time delay and ray bending experiments

    Performance Monitoring of Control Systems using Likelihood Methods

    Get PDF
    Evaluating deterioration in performance of control systems using closed loop operating data is addressed. A framework is proposed in which acceptable performance is expressed as constraints on the closed loop transfer function impulse response coefficients. Using likelihood methods, a hypothesis test is outlined to determine if control deterioration has occurred. The method is applied to a simulation example as well as data from an operational distillation column, and the results are compared to those obtained using minimum variance estimation approaches

    Estimation of Cross Directional Properties: Scanning versus Stationary Sensors

    Get PDF
    Periodic time varying Kalman filter calculations for problems involving scanning sensors are solved using "lifting" techniques common for multirate systems. The solution of this problem is used to compare the performance of scanning sensors versus stationary sensors in the estimation of cross directional properties. Furthermore, we examine controller performance when the outputs from the Kalman filter are used as inputs to a state feedback control law. Although adding sensors may significantly enhance the estimates of cross directional properties, feedback of these improved estimates may translate to lower levels of improvement in cross directional variations

    Optimal and Robust Design of Integrated Control and Diagnostic Modules

    Get PDF
    The problem of designing an integrated control and diagnostic module is considered. The four degree of freedom controller is recast into a general framework wherein results from optimal and robust control theory can be easily implemented. For the case of an H2 objective, it is shown that the optimal control-diagnostic module involves constructing an optimal controller, closing the loop with this controller, and then designing an optimal diagnostic module for the closed loop. When uncertain plants are involved, this two-step method does not lead to reasonable diagnostics, and the control and diagnostic modules must be synthesized simultaneously. An example shows how this design can be accomplished with available methods

    Understanding the relationship between weather conditions and home run rates in the MLB

    Get PDF
    Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.Cataloged from PDF version of thesis.Includes bibliographical references (page 24).This observational study explores the relationship between home run rates and weather conditions, both on game day and over the preceding weeks. Data were collected from ESPN and Weather Underground for over 36,000 games between the 2003 and 2017 seasons. These consisted of game statistics and 59 weather variables. Random Forests was used to determine which set of these variables were important predictors of home run rates. Humidity was found to be the most important weather variable for predicting home run rates. The data suggest that a change of game day humidity from 100% to 0% can increase home run rates by 27% and ball travel by 15ft. For access to the data, please visit tylerashoff.com.by Tyler Ashoff.S.B
    corecore