查询词典 characteristic boundary value problem

The problem of PI controller design for the multi-input and multi-output system is transformed to that of static output feedback controller design via the new state variable. As to the problem of the static output feedback, a new LMI-based sufficient condition of the controller is presented in this thesis. We can gain the multivariable PI controllers just solving one LMI inequality. The numerical example is provided to illustrate the proposed design approach. 3.The H_∞ robust control is able to solve the multivariable problem, also the control problem characteristic of the modeling error, parameters uncertainties and unknown perturbation, Its application research in the power electronics is beginning now. Considering the characteristics of the PWM DC-DC converters, a multivariable PI controllers which is based on H_∞ Performance Index is designed.

通过构造新的状态变量，可以将多输入多输出系统的PI控制器设计问题转化为静态输出反馈控制问题，利用后者的成熟理论来设计控制器；本文在问题转化后采用更为简便的算法，只需通过求解一个LMI不等式，就能求取基于H_∞性能指标的多变量PI控制器参数，实例验证了算法的有效性。3.H_∞鲁棒控制具有处理多变量问题的能力，可解决具有建模误差、参数不确定和干扰未知系统的控制问题；它在电力电子学中的应用研究刚刚开始。

The boundary element method for the Riemann-Hilbert boundary value problems for the generalized analytic function uses Cauchy integral formula as the foundation . The singularity of the Cauchy

广义解析函数的Riemann-Hilbert边值问题的边界元方法是以Cauchy公式为基础，Cauchy核具有奇性，这是所面临的困难，可以设法利用Cauchy主值积分来解决，最后给出问题的解。

For the optical system with circular apertures,it is difficult to get the boundary radical slope of phase and the accurate sampling value in the circular domain boundary when the intensity transport equation is used to recover the original phase.

1引言相位恢复是指利用光束传播时所探测到的光强信息反演出相位[1]，为了获得更多的光强信息以把相位恢复到最佳，一次光强测量是不够的，因此这就要求在光学系统的输出或成像光轴方向上进行多次光强测量。

The nonlinear functional for singularly perturbed boundary value problems for elliptic equation with boundary perturbation is considered.

研究了具有边界摄动的非线性泛函椭圆型方程奇摄动边值问题。

As known, using the porential theory Green's tormulae and the fundamental solutions wecan reduce the harmonic and biharmonic elliptic boundary value problems to integral equationson the boundary.

我们熟知，利用位势理论或由Green公式及基本解出发区域内调和及重调和边值问题可归化为边界上的积分方程。

In 1970s, boundary value problems with equivalued surface are put forward. Andit is important to study them to solve practical problems. Li Ta-tsien and his partnersdo systematic research on them, especially study certain kind of elliptic boundary valueproblem with equivalued surface on the domain with thin layer.

二十世纪七十年代提出了一类等值面边值问题，它对于解决实际问题起到了非常重要的作用，李大潜等人对其进行了比较系统的研究，特别的对在具有薄层的区域上的椭圆型等值面边值问题进行了探讨。

First, the physical models associated with dislocations and cracks are respectively converted to mixed boundary value problems in mathematics. Secondly, by using the Fourier transform, a dual integral equation for a crack and an algebraic equation for a dislocation can be derived from the boundary conditions relating with a crack and a dislocation, respectively. Solving these equations, exact analytical solutions can be obtained in terms of Bessel functions in close-form.

先把位错和裂纹的物理模型写成与它们相关的边值问题，然后，利用Fourier变换将这些边值问题化成一个对偶积分方程(对位错而言，得到一个代数方程)，求解此对偶积分方程，可以获得以Bessel函数给出的封闭形式的分析解。

We consider the existence of positive solutions of second order impulsive boundary value problems by constructing the appropriate homotopy operator and applying the theory of fixed point index in cones. our results contain the conclusion when f ≥ 0 and J_k = 0([6]). Secondly, we discuss multiple positive solutions of the following impulsive boundary

其次，我们在§2.2中讨论了下面的脉冲微分边值问题多正解的存在性在这一部分的讨论中，利用不动点指数理论，在f既非超线性又非次线性的情形下，得到了两个正解的存在性定理，把文[7]的结果推广到脉冲微分边值

The growth of functions in these spaces depends on a weighted function ρ. We investigate the relation between growth and boundary values of the functions, and prove that a function or its radial derivative is in one of the spaces if and only if the p'integral average of the difference of its boundary value function is integrable or bounded.

研究这些函数空间中函数的增长性与边界值的关系，得到了函数或其径向导数属于相应空间的充分必要条件是其边界值差分的p次积分平均应具备一定的可积性或有界性。

Finally, we study the continuous reliant relation of solutions and initial-boundary condition , give the stability analysis by studying the limit relation of solutions of several initial-boundary value problems.

最后，研究了解对初边界条件的连续的依赖关系，具体通过研究迎头法与宽脉冲、迎头法与渐变迎头法、宽脉冲与δ脉冲、宽脉冲与渐变宽脉冲等几类特殊初边值问题解之间的极限关系来进行稳定性分析。

We stopped by the old fashion ice cream parlor Manhattan Beach Creamery for some refreshment. The "No Shoes, No Shirt, No Problem" sign on the wall epitomizes the beach lifestyle.

我们去商店区的一家老式冰淇淋店坐坐，墙上挂著「没鞋，没上衣，没问题」的牌子完全捕捉了海滩生活的随性及风格。

"If therefore", argues Bellarmine we can offer our prayers and our satisfactions in behalf of those detained in purgatory, because we are members of the great body of Christ, why may not the Vicar of Christ apply to the same souls the superabundant satisfaction of Christ and his saints--of which he is the dispenser?

" "因此，如果"，认为贝拉明（德indulgentiis ，十四）"我们可以提供我们的祈祷和我们满意的代表那些被拘留在炼狱，因为我们是成员的伟大基督的奥体，为什麼可能不是牧师基督适用於同样的灵魂满意的过剩是耶稣和他的圣人-他是在配药？