2,636 research outputs found

    Social studies in secondary schools in Western Germany after World War II

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    Thesis (M.A.)--Boston Universit

    Quasi-optimum design of control systems for moving base simulators

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    Optimal control of six degree of freedom moving-base simulato

    Flavor Gauge Models Below the Fermi Scale

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    The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an additional gauge symmetry in the third generation. Specifically, we construct and analyze an explicit, renormalizable model with a gauge boson, XX, corresponding to the BLB-L symmetry of the third family. Having a relatively light (in the MeV to multi-GeV range), flavor-nonuniversal gauge boson results in a variety of constraints from different sources. By systematically analyzing 20 different constraints, we identify the most sensitive probes: kaon, B+B^+, D+D^+ and Upsilon decays, DDˉ0D-\bar{D}^0 mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling gXg_X in the range (102104)(10^{-2} - 10^{-4}) the model is shown to be consistent with the data. Possible ways of testing the model in bb physics, top and ZZ decays, direct collider production and neutrino oscillation experiments, where one can observe nonstandard matter effects, are outlined. The choice of leptons to carry the new force is ambiguous, resulting in additional phenomenological implications, such as non-universality in semileptonic bottom decays. The proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.Comment: 44 pages, 7 figures, 3 tables; B physics constraints and references added, conclusions unchange

    Optimised configuration of sensors for fault tolerant control of an electro-magnetic suspension system

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    For any given system the number and location of sensors can affect the closed-loop performance as well as the reliability of the system. Hence, one problem in control system design is the selection of the sensors in some optimum sense that considers both the system performance and reliability. Although some methods have been proposed that deal with some of the aforementioned aspects, in this work, a design framework dealing with both control and reliability aspects is presented. The proposed framework is able to identify the best sensor set for which optimum performance is achieved even under single or multiple sensor failures with minimum sensor redundancy. The proposed systematic framework combines linear quadratic Gaussian control, fault tolerant control and multiobjective optimisation. The efficacy of the proposed framework is shown via appropriate simulations on an electro-magnetic suspension system
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