排序方式: 共有39条查询结果,搜索用时 112 毫秒
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This paper deals with robustness of adaptive control of continuoussystems subject to known output delay, input saturation, unmodelledlinear dynamics, and bounded disturbances. A simple gradient-typealgorithm with a relative deadzone is used. The relative deadzoneis built with an estimated contribution of the unmodelled dynamicsto the system output. The basic tool used for stability androbustness analysis is Gronwall's lemma. 相似文献
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构造型几何定理及其机器证明系统 总被引:1,自引:0,他引:1
Hilbert 机械化定理表明,Pascal 几何中构造型交点定理可以机器证明。1982年,吴文俊教授给出了机械化定理的构造性证法。本文指出,通过添加若干新的构造类型,有更广泛的一类平面几何定理,其机器证明可以按照同样的构造性证法实现,我们称这类定理为构造型几何定理。作者适当调整吴文俊算法的步骤,在 HP1000小型计算机上建立了构造型几何定理的机器证明系统,效率大大提高,从而成功地证明了许多不平凡的几何定理,并且独立发现了相当深入的结果。 相似文献
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Abstract This paper is devoted to investigate extinction and nonextinction conditions of the extended Beverton–Holt equation (BHE) for dynamics of populations in Ecology when potential discontinuities at sampling points are included in the model. The proposed model is described by means of four sequences of parameters. Two of them are the intrinsic growth rate and the carrying capacity sequences which are included in the basic BHE model. The other two ones, namely, the harvesting (i.e., the hunting or fishing quota) and the internal consumption (which can include positive and negative migrations in the considered population habitat) sequences are included to parameterize the model discontinuities. Such discontinuities are related to impulses in the corresponding continuous‐time logistic equation. The obtained results establish how the harvesting quota and/or the internal consumption has to be fixed to guarantee the population nonextinction or, eventually, its extinction. Finally, some controllability results related to the search of a carrying capacity sequence such that the solution of the proposed impulsive BHE tracks a reference one are obtained. 相似文献
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POONAM ARORA AMRITA AWASTHI VATTIKONDA BHARATH AISHIK ACHARYA SUCHI YADAV ASHISH AGARWAL AMITAVA SEN GUPTA 《Pramana》2014,82(2):173-183
Frequency corresponding to the energy difference between designated levels of an atom provides precise reference for making a universally accurate clock. Since the middle of the 20th century till now, there have been tremendous efforts in the field of atomic clocks making time the most accurately measured physical quantity. National Physical Laboratory India (NPLI) is the nation’s timekeeper and is developing an atomic fountain clock which will be a primary frequency standard. The fountain is currently operational and is at the stage of complete frequency evaluation. In this paper, a brief review on atomic time along with some of the recent results from the fountain clock will be discussed. 相似文献
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The study of the dynamics of 1D chains with both harmonic and nonlinear interactions, as in the Fermi–Pasta–Ulam (FPU) and
related problems, has played a central role in efforts to identify the broad consequences of nonlinearity in these systems.
Here we study the dynamics of highly localized excitations, or discrete breathers, which are known to be initiated by the
quasistatic stretching of bonds between adjacent particles. We show via dynamical simulations that acoustic waves introduced
by the harmonic term stabilize the discrete breather by suppressing the breather’s tendency to delocalize and disperse. We
conclude that the harmonic term, and hence acoustic waves, are essential for the existence of localized breathers in these
systems. 相似文献