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991.
朱方生 《武汉大学学报(理学版)》1995,(3)
构造了线性二次型最优控制的并行算法,介绍了这个并行算法在武汉大学“WUDP91”并行分布式处理系统上试算的数值应用软件的框图.本软件适用于既定动态系统的平衡问题.对于经济系统,可通过政策控制变量来调节和改善其状态和响应.对于自治系统可找出最优控制使得消耗函数达到最小值.通过对一系列例子进行试算,结果证实,所构造的并行算法和相应的数值软件是有效的,其加速比约为7. 相似文献
992.
In this paper, by means of monotone iterative technique, a necessary and sufficient condition of the existence of positive solution for a class of nonlinear singular differential system is established, the results of the existence and uniqueness of the positive solution and the iterative sequence of solution are given. In the end, two classes extending boundary value differential systems are discussed and some further results are obtained. 相似文献
993.
M. Drewsen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):125-127
We briefly discuss some possibilities for cooling, identification and spectroscopy of super-heavy element (SHE) ions based
on recent results obtained from studies of atomic and molecular ions in linear rf traps. Since these investigations only relied
on the charge and the mass of the ion of interest, we believe it should be straight forward to adopt most of the techniques
for SHE ion research. 相似文献
994.
A phase-only encryption scheme using phase-encoded exclusive-OR (XOR) rules in a Fourier plane and a single path decryption
system are presented. To generate phase-only encrypted data, a zero-padded original image, multiplied by a random phase image,
is Fourier transformed and its real-valued data is encrypted with key data by using phase-encoded XOR rules. Since the original
information is encrypted on the Fourier plane, the proposed encryption is more tolerant to loss of key information by scratching
or cutting than previous XOR encryption in a space domain. A decryption is simply performed based on 2-f setup with spatial
filter by Fourier transform for multiplication phase-only encrypted data with phase-only key data. Due to single path architecture
without a reference wave, the proposed system is resistant to mechanical vibrations and fluctuation. Numerical simulations
have confirmed the validity of the proposed encryption scheme and simple decryption architecture. 相似文献
995.
应用多尺度微扰理论到广义非简谐振子, 得到了一阶经典和量子微扰解. 特别是
我们的量子解在极限条件下能方便地转变为经典解, 并且坐标和动量算符的对易
关系的简化十分自然. 与Taylor级数解相比较, 无论是在经典还是在量子解
中频率移动都出现在各阶振动表达式中, 所以多尺度微扰解是弱耦合非简谐振动的较好解法. 相似文献
996.
We consider a four-dimensional generalization of Hess–Appel’rot system and costruct its Lax pair. Both classical and algebro-geometric integration procedure are proceeded. The algebro-geometric integration is based on deep facts from geometry of Prym varieties such as the Mumford relation and Mumford-Dalalyan theory. The integration is similar to the integration of Lagrange bitop which has recetly been performed by the authors. 相似文献
997.
We investigate traces of functions, belonging to a class of functions with dominating mixed smoothness in ℝ3, with respect to planes in oblique position. In comparison with the classical theory for isotropic spaces a few new phenomenona
occur. We shall present two different approaches. One is based on the use of the Fourier transform and restricted to p = 2. The other one is applicable in the general case of Besov-Lizorkin-Triebel spaces and based on atomic decompositions. 相似文献
998.
We examine the resource allocation problem of partitioning identical servers into two parallel pooling centers, and simultaneously
assigning job types to pooling centers. Each job type has a distinct Poisson arrival rate and a distinct holding cost per
unit time. Each pooling center becomes a queueing system with an exponential service time distribution. The goal is to minimize
the total holding cost. The problem is shown to be polynomial if a job type can be divided between the pooling centers, and
NP-hard if dividing job types is not possible. When there are two servers and jobs cannot be divided, we demonstrate that
the two pooling center configuration is rarely optimal. A heuristic which checks the single pooling center has an upper bound
on the relative error of 4/3. The heuristic is extended for the multiple server problem, where relative error is bounded above
by the number of servers.
相似文献
999.
Irina Markina 《Journal of Functional Analysis》2007,245(2):475-492
We consider coefficient bodies Mn for univalent functions. Based on the Löwner-Kufarev parametric representation we get a partially integrable Hamiltonian system in which the first integrals are Kirillov's operators for a representation of the Virasoro algebra. Then Mn are defined as sub-Riemannian manifolds. Given a Lie-Poisson bracket they form a grading of subspaces with the first subspace as a bracket-generating distribution of complex dimension two. With this sub-Riemannian structure we construct a new Hamiltonian system to calculate regular geodesics which turn to be horizontal. Lagrangian formulation is also given in the particular case M3. 相似文献
1000.
一种结合了基于任务的访问控制模型TBAC和基于角色的访问控制模型RBAC特点的新型访问控制模型-T-RBAC.该模型采用了以任务为中心的"用户-角色-任务-权限"的四级访问控制结构,较好地解决了当前工作流系统中存在的安全性问题.此外,在新模型的基础上设计了一套描述约束机制的语言ETCL,该语言在RCL2000的基础上扩充了时间特性和任务的概念,使新模型具备了较完整的约束描述能力. 相似文献