1,189 research outputs found

    Sensitivity bond graphs

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    A sensitivity bond graph, of the same structure as the system bond graph, is shown to provide a simple and effective method of generating sensitivity functions of use in optimisation. The approach is illustrated in the context of partially known system parameter and state estimation

    On the stick-slip vibration in the suspension of a freight wagon

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    Undoing Reform: How and Why One School Leader Cleared a Shifting Path to Goal Attainment

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    Research on school reform highlights challenges school leaders face in implementing and sustaining reforms. While some efforts fade away, others are intentionally dismantled, or ā€œundoneā€ as schools revert back to their traditional model of schooling. Considering how often reforms fail to sustain, there is value in understanding why school leaders decide undo reforms, and how leaders support staff through the undoing process. Utilizing path-goal theory as a framework, this paper I examined the case of one elementary school principal who planned in this undoing of a competency-based reform she had previously championed. Analysis reveals that the shift back to a traditional approach to instruction was in response to changes in state policies and district resource allocations, and that the type of support the school leader provided to teachers during the undoing was strongly influenced by the characteristics of the each stage of the process

    Post Conviction Remedies

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    Federal habeas corpus relief first became available to state prisoners in 1867, when the Judiciary Act, which originally applied only to federal prisoners, was amended. Historically, habeas corpus inquiry had been restricted to the question of whether the convicting tribunal had jurisdiction over the person of the defendant and the subject matter of the offense. However, the scope of the federal writ has been gradually expanded until it is now used to test the constitutional validity of a conviction. At the same time, the Supreme Court has placed several limitations upon the availability of federal habeas corpus to state prisoners. I. Traditional Remedies II. Statutory Remedies III. Judicial Expansion of Traditional Remedies IV. Conclusio

    Guest Editor's Preface

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    Physical interpretation of inverse dynamics using bicausal bond graphs

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    A physical interpretation of the inverse dynamics of linear and nonlinear systems is given in terms of the bond graph of the inverse system. It is argued that this interpretation yields physical insight to guide the control engineer. Examples are drawn from both robotic and process systems

    Data compression for estimation of the physical parameters of stable and unstable linear systems

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    A two-stage method for the identification of physical system parameters from experimental data is presented. The first stage compresses the data as an empirical model which encapsulates the data content at frequencies of interest. The second stage then uses data extracted from the empirical model of the first stage within a nonlinear estimation scheme to estimate the unknown physical parameters. Furthermore, the paper proposes use of exponential data weighting in the identification of partially unknown, unstable systems so that they can be treated in the same framework as stable systems. Experimental data are used to demonstrate the efficacy of the proposed approach

    Estimation and control of mechatronic systems using sensitivity bond graphs

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    A new bond graph framework for sensitivity theory is applied to model-based predictive control, state estimation, and parameter estimation in the context of physical systems. The approach is illustrated using a nonlinear mechatronic system

    On the oscillations of statically indeterminate beams

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    The Problem of determining the natural frequencies and modes of a statically indeterminant, Timoshenko beam is considered. By lumping the beam properties of linear and rotary inertia at discrete points along the length of the beam and by employing the complementary, variational principle, an approximate solution is obtained by simple matrix iteration. Das Problem der Bestimmung von Eigenfrequenzen und Schwingungsformen eines statisch unbestimmten Timoshenko trƤgers wird behandelt. Durch Zusammenziehung der TrƤgereigenschaften von Masse und Drehmasse an diskreten Punkten entlang des TrƤgers und durch Anwendung des komplementƤren Variationsprinzips wird eine NƤherungslƶsung durch einfache Matrizeniteration erreicht.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41724/1/707_2005_Article_BF01176614.pd
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