炮控伺服系统自抗扰控制器优化设计

针对自抗扰控制器参数难于整定的问题,给出了一种基于自适应变异粒子群优化算法的炮控伺服系统自抗扰控制器优化设计方法.该算法结构简单,具有良好的全局收敛性,充分发挥了自抗扰控制器的控制性能.通过对某炮控伺服系统的仿真研究,表明了该设计方法的有效性.     

Scheduling parallel machines with inclusive processing set restrictions

We consider the problem of assigning a set of jobs to different parallel machines of the same processing speed, where each job is compatible to only a subset of those machines. The machines can be linearly ordered such that a higher‐indexed machine can process all those jobs that a lower‐indexed machine can process. The objective is to minimize the makespan of the schedule. This problem is motivated by industrial applications such as cargo handling by cranes with nonidentical weight capacities, computer processor scheduling with memory constraints, and grades of service provision by parallel servers. We develop an efficient algorithm for this problem with a worst‐case performance ratio of + ε, where ε is a positive constant which may be set arbitrarily close to zero. We also present a polynomial time approximation scheme for this problem, which answers an open question in the literature. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

稳定自组织网络结构中单点突变对网络稳定性影响

从战场恶劣环境通信设备无法正常通信的条件下,介绍了一种自组织网络稳定度的模型。通过比较自组织网络结构中微结构和巨结构的优缺点,动态地描述了结构间的聚合和裂解。基于结构分析,考虑单点突变对网络稳定性的影响,从时间因素策略方面,提出了一个基于预测最稳定链路生存时间的一种分布式成群策略。通过合理建模以及优化路由算法,尽可能地维护网络结构的稳定。     

适应低时延业务需求的分布式可穿戴单兵作战信息系统

针对云计算应用在单兵作战系统场景下业务处理时延高、服务质量无法保障的问题,提出一种基于可穿戴计算的分布式单兵作战信息系统。利用士兵身上的可穿戴智能设备构建本地计算层,在作战地点就近处理计算数据,提供给士兵本地的信息处理与融合能力,并采用广义扩散负载均衡算法平衡各设备负载,降低业务处理时延;同时利用分布式计算的容错能力增强系统的可靠性。仿真结果表明,基于可穿戴设备的分布式本地网络架构能有效地降低作战任务的处理时延,同时增强系统的可靠性。     

Bin‐packing problem with concave costs of bin utilization

We consider a generalized one‐dimensional bin‐packing model where the cost of a bin is a nondecreasing concave function of the utilization of the bin. Four popular heuristics from the literature of the classical bin‐packing problem are studied: First Fit (FF), Best Fit (BF), First Fit Decreasing (FFD), and Best Fit Decreasing (BFD). We analyze their worst‐case performances when they are applied to our model. The absolute worst‐case performance ratio of FF and BF is shown to be exactly 2, and that of FFD and BFD is shown to be exactly 1.5. Computational experiments are also conducted to test the performance of these heuristics. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

Analysis of practical policies for a single link distribution system

In this paper we consider a transportation problem where several products have to be shipped from an origin to a destination by means of vehicles with given capacity. Each product is made available at the origin and consumed at the destination at the same constant rate. The time between consecutive shipments must be greater than a given minimum time. All demand needs to be satisfied on time and backlogging is not allowed. The problem is to decide when to make the shipments and how to load the vehicles with the objective of minimizing the long run average of the transportation and the inventory costs at the origin and at the destination over an infinite horizon. We consider two classes of practical shipping policies, the zero inventory ordering (ZIO) policies and the frequency‐based periodic shipping (FBPS) policies. We show that, in the worst‐case, the Best ZIO policy has a performance ratio of . A better performance guarantee of is shown for the best possible FBPS policy. The performance guarantees are tight. Finally, combining the Best ZIO and the Best FBPS policies, a policy that guarantees a performance is obtained. Computational results show that this policy gives an average percent optimality gap on all the tested instances of <1%. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

一种含最优变异的多微粒群优化算法

针对微粒群优化算法中的固有缺点,提出了带有最优变异算子的多微粒群优化算法,采用多个微粒群对目标函数进行寻优,并在寻优过程中对子群中最优微粒引入了最优变异算子。通过这样的处理,算法可以预防早熟收敛并具有更快的收敛速度和更好的局部开发能力。对一组测试函数的模拟实验结果表明,带最优变异的多微粒群优化算法可以摆脱局部最优解对微粒的吸引,在较少的代数内就能够获得好的优化结果。     

MFSK/FFH系统分集合并算法性能对比研究

推导了部分频带干扰最佳干扰系数表达式并进行了仿真验证,描述了多进制频移键控/快跳频(MFSK/FFH)系统、衰落信道和分集合并算法模型,在最坏部分频带干扰和衰落信道下,仿真对比了MFSK/FFH系统采用线性分集合并、限幅线性分集合并、自归一分集合并、排序统计自归一分集合并、乘积分集合并5种分集合并算法时的误码率性能,结果表明:在最坏部分频带干扰和衰落信道下,线性合并性能较差,其他4种算法性能较为相似,Rayleigh衰落信道中排序统计自归一分集合并和乘积分集合并算法性能最优。     

针对官兵能力个体差异做好部队训练工作

正确认识能力的多样性及个体差异,有利于增强部队训练工作的科学性,提高战斗力。由于“能力”理解的多样性,对部队训练能力的认识也具有多个层面的涵义。个体在部队训练中体现出发展水平、结构、表现时间以及性别的差异。正确认识这些差异需要走出认知上的误区,做好“两头人”的工作,充分发挥“三互小组”的作用以及制定不同阶段的具体目标等。     

经济视角下的《骆驼祥子》

老舍在《骆驼祥子》中采用经济视角,与自身的生活经历和时代背景有关。通过在作品中运用经济视角探究人的解放、展开社会批判、进行伦理剖析,比较客观地还原了生活的本真和人生的本相,让读者透视了经济生活表象下蕴含的精神内涵。