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81.
Backstepping-based lag synchronization of a complex permanent magnet synchronous motor system 下载免费PDF全文
Through introducing the concept of complex current and resetting cross-coupling term, this paper proposes a novel complex permanent magnet synchronous motor system and analyzes its properties. Based on a complex permanent magnet synchronous motor system, we design controllers and achieve lag synchronizations both in real part and imaginary part with backstepping method. In our study, we take complex current, time delay, and structure of complex system into consideration. Numerical simulation results demonstrate the validity of controllers. 相似文献
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The chaos expansion of a general non-linear function of a Gaussian stationary increment process conditioned on its past realizations is derived. This work combines the Wiener chaos expansion approach to study the dynamics of a stochastic system with the classical problem of the prediction of a Gaussian process based on a realization of its past. This is done by considering special bases for the Gaussian space 𝒢 generated by the process, which allows us to obtain an orthogonal basis for the Fock space of 𝒢 such that each basis element is either measurable or independent with respect to the given samples. This allows us to easily derive the chaos expansion of a random variable conditioned on part of the sample path. We provide a general method for the construction of such basis when the underlying process is Gaussian with stationary increment. We evaluate the basis elements in the case of the fractional Brownian motion, which leads to a prediction formula for this process. 相似文献
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** Email: haelsaify{at}yahoo.com In this paper, we study the linear quadratic optimal boundarycontrol problem for n x n coupled system of infinite-order parabolicpartial differential equation, in which time-varying lags appearin the state equation and in the Neumann boundary conditionsimultaneously. By Lions scheme, necessary and sufficient conditionof optimality for the Neumann problem with quadratic functionaland constraint control is derived. Finally, several mathematicalexamples for derived optimality conditions are presented. 相似文献
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《Mathematical Methods in the Applied Sciences》2018,41(12):4549-4559
Runge‐Kutta pairs sharing orders 5 and 4 are among the most celebrated methods for solving initial value problems. Here, after considering the phase lag as a function of frequency v, we derive a modification of a particular pair. Namely, we present a zero dissipative pair with vanished phase error and its first derivative. After extended numerical tests in various oscillatory problems, it seems that this modified pair outperforms existing methods in the literature. 相似文献
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《Mathematical Methods in the Applied Sciences》2018,41(5):1845-1854
We consider the integration of the special second‐order initial value problem of the form . A recently introduced family of 7 stages, eighth‐order methods, sharing constant coefficients, is used as base. This family is properly modified to derive phase fitted and zero dissipative methods (ie, trigonometric fitted) that are best suited for integrating oscillatory problems. Numerical tests over a set of problems shows enhanced performance when the purely linear part of the problems is rather large in comparison with the rest of nonlinear parts. An appendix implementing a MATLAB listing with the coefficients of the new method is also given. 相似文献
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导出了波纹内导体同轴慢波结构热腔色散方程,研究了周期波纹深度、电子注平均半径、电子注电流及加速电压对波纹内导体慢波结构的高频场时间增长率的影响。结果表明:慢波结构周期减小、波纹深度加深、电子注平均半径减小、电子注电流增大、加速电压增大均会使高频场时间增长率增大。建立了粒子模型并应用PIC粒子模拟软件进行仿真,对各影响参数进行优化,结果表明:当加速电压为0.5 MV、电子束电流85 kA、波纹周期长度4.4 cm、波纹幅度为0.23 cm、内轴平均半径为2.9 mm和外壁内径为4.4 cm时,可获得10 GHz,1.1 GW效率约25%的单频微波输出。 相似文献
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