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1.
基于无穷维空间中的生存定理,我们研究了集值映象的不动点,得到了一个新的不动点定理,推广和改进了[1]和[5]中的相应结果。 相似文献
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Some effective methods for unconstrained optimization based on the solution of systems of ordinary differential equations 总被引:5,自引:0,他引:5
A. A. Brown M. C. Bartholomew-Biggs 《Journal of Optimization Theory and Applications》1989,62(2):211-224
In this paper, we review briefly some methods for minimizing a functionF(x), which proceed by follwoing the solution curve of a system of ordinary differential equations. Such methods have often been thought to be unacceptably expensive; but we show, by means of extensive numerical tests, using a variety of algorithms, that the ODE approach can in fact be implemented in such a way as to be more than competitive with currently available conventional techniques.This work was supported by a SERC research studentship for the first author. Both authors are indebted to Dr. J. J. McKeown and Dr. K. D. Patel of SCICON Ltd, the collaborating establishment, for their advice and encouragement. 相似文献
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This paper describes a numerical realization of an extended continuous Newton method defined by Diener. It traces a connected set of locally one-dimensional trajectories which contains all critical points of a smooth functionf:
n
. The results show that the method is effectively applicable.The authors would like to thank L. C. W. Dixon for pointing out some errors in the original version of this paper and for several suggestions of improvements. 相似文献
5.
基于PuH_2分子基态(X~7A_1)的分析势能函数,用准经典的Monte-Carlo轨线法 对Pu(~7Fg)+H_2(X~1∑_g~+,0,0)的分子反应动力学过程进行了计算。结果表明 :Pu(~7F_g)与H_2(X~1∑_g~+,0,0)碰撞是弹性碰撞。 相似文献
6.
超大型航天结构具有超大柔性、超低固有频率的特点,空间机器人在轨组装时应尽可能避免激起超大型结构的柔性振动.空间机器人组装超大型结构模块的过程分成抓捕阶段、位姿调整与稳定阶段、安装阶段和爬行阶段.通过对安装阶段的动力学与控制研究,提出共线安装的轨迹规划方法,有效避免了柔性结构振动.首先,采用自然坐标法和绝对节点坐标法建立主结构-空间机器人-待组装结构的在轨组装系统动力学模型.然后,将共线安装的要求转化为空间机器人的轨迹规划约束,要求空间机器人质心到主结构/待组装结构的距离保持不变,实现共线安装的轨迹规划.数值仿真表明:提出的组装方法在组装过程中可有效避免超大型结构的横向运动,降低夹持力矩.最后,分析了系统参数对组装过程动力学响应的影响,为超大型航天器的在轨组装提供了参考. 相似文献
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A time-parallel simulation obtains parallelism by partitioning the time domain of the simulation. An approximate time-parallel simulation algorithm named GG1K is developed for acyclic networks of loss FCFSG/G/1/K queues. The GG1K algorithm requires two phases. In the first phase, a similar system (i.e. aG/G/1/ queue) is simulated using the GLM algorithm. Then the resultant trajectory is transformed into an approximateG/G/1/K trajectory in the second phase. The closeness of the approximation is investigated theoretically and experimentally. Our results show that the approximation is highly accurate except whenK is very small (e.g. 5) in certain models. The algorithm exploits unbounded parallelism and can achieve near-linear speedup when the number of arrivals simulated is sufficiently large. 相似文献
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The effect of vibrational excitation of HBr on the H+HBrH2+Br and H+HBrH+HBr reactions has been investigated on the extended LEPS surface (ELEPS) constructed on the basis of quantum chemically calculated points of PES. Together with this surface the LEPS surface of Sudhakaran and Raff [1] was used for comparison at two relative translational energies. A quasiclassical trajectory method was used to study the abstraction and exchange reaction dynamics. The reactive cross section was calculated as a function of the relative collision energy and the vibrational state of HBr. The following conclusions can be drawn from the results of the study: (i) vibrational excitation v=0 v=2 more than doubles the reaction cross section, (ii) the increase in the collision energy is most effectively channelled into the product translational energy.Dedicated to Professor J. Koutecký on the occasion of his 65th birthday 相似文献
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