一类高次多项式系统极限环的讨论

通过变换将一类高次多项式系统化为Lienard系统,利用Hopf分枝定理和张芷芬唯一性定理,证明了该类系统极限环的存在性与唯一性。     

链约束下加工时间恶化的Flow Shop排序问题

讨论作业具有线性加工时间,作业间具有链约束的两台处理机流水作业排序问题,目标函数为极小化完工时间。在作业加工时间简单线性恶化下,提出作业的非负开始和停止延迟恶化率,构造了满足约束条件的复合作业。在此基础上,给出作业间具有平行链约束的两台处理机流水作业排序问题的最优多项式算法。     

Neighborhood search heuristics for selecting hierarchically well‐formulated subsets in polynomial regression

The importance of subset selection in multiple regression has been recognized for more than 40 years and, not surprisingly, a variety of exact and heuristic procedures have been proposed for choosing subsets of variables. In the case of polynomial regression, the subset selection problem is complicated by two issues: (1) the substantial growth in the number of candidate predictors, and (2) the desire to obtain hierarchically well‐formulated subsets that facilitate proper interpretation of the regression parameter estimates. The first of these issues creates the need for heuristic methods that can provide solutions in reasonable computation time; whereas the second requires innovative neighborhood search approaches that accommodate the hierarchical constraints. We developed tabu search and variable neighborhood search heuristics for subset selection in polynomial regression. These heuristics are applied to a classic data set from the literature and, subsequently, evaluated in a simulation study using synthetic data sets. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

考虑直流侧线路阻抗时十二相发电机整流系统突然短路的研究

根据十二相同步发电机的数学模型,对考虑直流侧线路阻抗的十二相发电机整流供电系统直流侧突然短路过程进行了数字仿真及试验验证.分析了线路电阻和电感对短路电流的影响.     

励磁突变对无刷励磁同步发电机整流系统负载电流的影响

分析了无刷励磁同步发电机整流系统突加/突卸励磁时的过渡过程,得到了影响负载电流上升和下降时间的主要时间常数,并对理论分析结果进行了仿真和实验研究,仿真结果与理论分析吻合良好.实验波形所反映的变化趋势亦与仿真及理论分析结果较为符合.     

螺旋形爆炸磁压缩发生器

为了得到高电压的输出,从爆炸磁通量压缩发生器的工作原理入手,在单端起爆装置的基础上,设计了一种两端起爆的螺旋形爆磁发生器,并给出了实验结果和分析。     

基于小波神经网络的蒸汽发生器水位辨识与控制仿真

提出一种基于小波神经网络的控制方法,对蒸汽发生器水位进行控制仿真.该方法利用小波神经网络作为控制系统的辨识器和控制器来构成控制系统.小波神经网络辨识器能更准确逼近非线性对象,小波神经网络控制器能自适应产生最佳的控制规律.仿真结果表明,该方案具有响应快、超调量小、较强抑制干扰能力等良好性能.     

Limiting survival functions of self‐similar structures

We show the existence of a unique analytic single parameter limiting survival function arising from the repeated composition of a coherent structure as the number of components tends to infinity. Examples include the repeated composition process of the bridge structure. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

A dual criteria sequencing problem with earliness and tardiness penalties

We consider the problem of sequencing n jobs on a single machine, with each job having a processing time and a common due date. The common due date is assumed to be so large that all jobs can complete by the due date. It is known that there is an O(n log n)‐time algorithm for finding a schedule with minimum total earliness and tardiness. In this article, we consider finding a schedule with dual criteria. The primary goal is to minimize the total earliness and tardiness. The secondary goals are to minimize: (1) the maximum earliness and tardiness; (2) the sum of the maximum of the squares of earliness and tardiness; (3) the sum of the squares of earliness and tardiness. For the first two criteria, we show that the problems are NP‐hard and we give a fully polynomial time approximation scheme for both of them. For the last two criteria, we show that the ratio of the worst schedule versus the best schedule is no more than . © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 422–431, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10020     

硅整流无刷发电机供电系统动态性能的研究

分析了坦克的供电系统中采用硅整流无刷发电机时的工作特点,建立了这种系统的数学模型,举例说明了计算方法,并在文章的最后进行了评价.