共查询到20条相似文献,搜索用时 78 毫秒
1.
拓扑有限交性质及极大极小定理* 总被引:1,自引:0,他引:1
本文研究了更一般的拓扑有限交的性质。作为应用,利用本文结果给出了更一般的极大极小定理。本文结果推广了[5,6,9]中的主要结果。 相似文献
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多层弹性导电板在磁场中的运动方程 总被引:2,自引:0,他引:2
本文得到了多层弹性导电板在磁场中的运动方程。着名的Амбарцумян薄板方程是本文的特殊情形。本文还对多层板的横向振动问题进行了讨论。 相似文献
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受约束控制系统中变分原理的应用* 总被引:2,自引:1,他引:1
本文分别对LQ控制问题及非线性控制问题建立了约束变量的正则方程,进而讨论了等式约束和不等式约束时约束变量的极值原理,最后通过例题验证了本文所得到的结论。本文工作为受约束LQ控制系统及非线性控制系统的深入研究打下了基础。 相似文献
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阮炯 《数学年刊A辑(中文版)》1988,(2)
本文讨论二阶具有非正系数的中立型与滞后型泛函微分方程,给出了这些方程的非振动解的类型以及判别条件。 对于cO情形(中立型),本文给出了四种S~*类的非振动解:对于|c|相似文献
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U—统计计量投影残差的指数收敛速度及其应用 总被引:2,自引:0,他引:2
本文研究了一样本U-统计量投影残差的收敛速度,在核函数有界及某种意义下的指数型有界时,本文得到了一些指数收敛速度,最后,利为上述结果的应用,本文还研究了刻度参数的变点问题。 相似文献
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本文研究了一样本U-统计量投影残差的收敛速度,在核函数有界及某种意义下的指数型有界时,本文得到了一些指数收敛速度,最后,利为上述结果的应用,本文还研究了刻度参数的变点问题. 相似文献
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本文首先研究了涉及两种货币市场的Hull-White随机利率模型.以此为基础,本文给出了交叉货币百慕大式互换期权的定价公式.由于无法得到显式定价公式,我们使用了Least Squared Monte-Carlo(LSM)算法来确定期权的最优执行时刻.最后本文给出了数值计算方面的结果. 相似文献
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在解析几何中有二次曲线与直线位置关系的讨论、二次曲面与直线位置关系的讨论,而二次曲面与平面相关位置关系的探讨较少.本文给出二次曲面a11x2+a22y2+a33z2+2a12xy+2a13xz+2a23yz+2a14x+2a24y+2a34z+a44=0(1)和平面Ax+By+Cz+D=0(2)的相对位置的判别式Δ=a11a12a13a14Aa21a22a23a24Ba31a32a33a34Ca41a42a43a44DA B C D0(aij=aji).(3)并证明了:若Δ>0,则二次曲面(1)与平面(2)相交;若Δ=0,则(1)和(2)相切;若Δ<0,则(1)和(2)相离. 相似文献
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研究了围绕曲线的管状曲面上的曲率线,渐近线与测地线,给出它们的方程,揭示了这些曲线与Bertrand曲线或Mannheim曲线之间的关系,采用新的方法给出一条曲线是Bertrand曲线或Mannheim曲线的充要条件的另一种证明以及Mannheim侣线的曲率与挠率之间的关系. 相似文献
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Yu Can Zhu 《数学学报(英文版)》2008,24(10):1727-1736
In this paper, we introduce the pre-frame operator Q for the g-frame in a complex Hilbert space, which will play a key role in studying g-frames and g-Riesz bases etc. Using the pre-frame operator Q, we give some necessary and sufficient conditions for a g-Bessel sequence, a g-frame, and a g-Riesz basis in a complex Hilbert space, which have properties similar to those of the Bessel sequence, frame, and Riesz basis respectively. We also obtain the relation between a g-frame and a g-Riesz basis, and the relation of bounds between a g-frame and a g-Riesz basis. Lastly, we consider the stability of a g-frame or a g-Riesz basis for a Hilbert space under perturbation. 相似文献
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For a convex closed bounded set in a Banach space, we study the existence and uniqueness problem for a point of this set that is the farthest point from a given point in space. In terms of the existence and uniqueness of the farthest point, as well as the Lipschitzian dependence of this point on a point in space, we obtain necessary and su.cient conditions for the strong convexity of a set in several infinite-dimensional spaces, in particular, in a Hilbert space. A set representable as the intersection of closed balls of a fixed radius is called a strongly convex set. We show that the condition “for each point in space that is sufficiently far from a set, there exists a unique farthest point of the set” is a criterion for the strong convexity of a set in a finite-dimensional normed space, where the norm ball is a strongly convex set and a generating set. 相似文献
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Le Thi Hoai An Pham Dinh Tao Nam Nguyen Canh Nguyen Van Thoai 《Journal of Global Optimization》2009,44(3):313-337
We propose a method for finding a global solution of a class of nonlinear bilevel programs, in which the objective function
in the first level is a DC function, and the second level consists of finding a Karush-Kuhn-Tucker point of a quadratic programming
problem. This method is a combination of the local algorithm DCA in DC programming with a branch and bound scheme well known
in discrete and global optimization. Computational results on a class of quadratic bilevel programs are reported. 相似文献
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Masaharu Taniguchi 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2019,36(7):1791-1816
For a balanced bistable reaction-diffusion equation, an axisymmetric traveling front has been well known. This paper proves that an axially asymmetric traveling front with any positive speed does exist in a balanced bistable reaction-diffusion equation. Our method is as follows. We use a pyramidal traveling front for an unbalanced reaction-diffusion equation whose cross section has a major axis and a minor axis. Preserving the ratio of the major axis and a minor axis to be a constant and taking the balanced limit, we obtain a traveling front in a balanced bistable reaction-diffusion equation. This traveling front is monotone decreasing with respect to the traveling axis, and its cross section is a compact set with a major axis and a minor axis when the constant ratio is not 1. 相似文献
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A tabu search heuristic for the dynamic transportation of patients between care units 总被引:1,自引:0,他引:1
The problem studied in this paper stems from a real application to the transportation of patients in the Hospital Complex of Tours (France). The ambulance central station of the Hospital Complex has to plan the transportation demands between care units which require a vehicle. Some demands are known in advance and the others arise dynamically. Each demand requires a specific type of vehicle and a vehicle can transport only one person at a time. The demands can be subcontracted to a private company which implies high cost. Moreover, transportations are subject to particular constraints, among them priority of urgent demands, disinfection of a vehicle after the transportation of a patient with contagious disease and respect of the type of vehicle needed. These characteristics involve a distinction between the vehicles and the crews during the modeling phase. We propose a modeling for solving this difficult problem and a tabu search algorithm inspired by Gendreau et al. (1999). This method supports an adaptive memory and a tabu search procedure. Computational experiments on a real-life instance and on randomly generated instances show that the method can provide high-quality solutions for this dynamic problem with a short computation time. 相似文献
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We consider a mathematical model which describes the frictional contact between a viscoelastic body and a reactive foundation. The process is assumed to be dynamic and the contact is modeled with a general normal damped response condition and a local friction law. We present a variational formulation of the problem and prove the existence and uniqueness of the weak solution, using results on evolution equations with monotone operators and a fixed point argument. We then introduce and study a fully discrete numerical approximation scheme of the variational problem, in terms of the velocity variable. The numerical scheme has a unique solution. We derive error estimates under additional regularity assumptions on the data and the solution. 相似文献
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We consider a mathematical model which describes the dynamic process of contact between a piezoelectric body and an electrically conductive foundation. We model the material’s behavior with a nonlinear electro-viscoelastic constitutive law; the contact is frictionless and is described with the normal compliance condition and a regularized electrical conductivity condition. We derive a variational formulation for the problem and then, under a smallness assumption on the data, we prove the existence of a unique weak solution to the model. We also investigate the behavior of the solution with respect the electric data on the contact surface and prove a continuous dependence result. Then, we introduce a fully discrete scheme, based on the finite element method to approximate the spatial variable and the backward Euler scheme to discretize the time derivatives. We treat the contact by using a penalized approach and a version of Newton’s method. We implement this scheme in a numerical code and, in order to verify its accuracy, we present numerical simulations in the study of two-dimensional test problems. These simulations provide a numerical validation of our continuous dependence result and illustrate the effects of the conductivity of the foundation, as well. 相似文献
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Takesi Kawasaki 《Transactions of the American Mathematical Society》2002,354(1):123-149
The Rees algebra is the homogeneous coordinate ring of a blowing-up. The present paper gives a necessary and sufficient condition for a Noetherian local ring to have a Cohen-Macaulay Rees algebra: A Noetherian local ring has a Cohen-Macaulay Rees algebra if and only if it is unmixed and all the formal fibers of it are Cohen-Macaulay. As a consequence of it, we characterize a homomorphic image of a Cohen-Macaulay local ring. For non-local rings, this paper gives only a sufficient condition. By using it, however, we obtain the affirmative answer to Sharp's conjecture. That is, a Noetherian ring having a dualizing complex is a homomorphic image of a finite-dimensional Gorenstein ring.