基于动平衡状态理论的非线性系统设计方法

基于动平衡状态理论的非线性设计方法是一种建立在控制系统动平衡状态渐近稳定概念上的新的设计方法.首先设计控制律使系统的动平衡状态按期望的方式运动,然后按某一指标设计系统,使其状态按最佳方式向动平衡状态收敛.使用此方法对非线性跟踪问题进行设计,设计过程简单清楚,仿真结果正确,并能更深刻反映动平衡状态的含义.     

含水声对抗模型的鱼雷武器作战仿真系统

以现代海战为背景,采用基于高层体系结构(High Level Architecture,HLA)的建模、开发软件平台Lab Works、pRTI构建了开放式、可扩展的鱼雷武器作战仿真系统.该系统在弹道仿真的基础上引入了水声对抗模型,将鱼雷自导解算模型和目标环境空间生成模型相耦合,组成能在一台微机上进行仿真解算的声信号处理联邦成员,避免了大量数据在网络上的传输.仿真运行结果显示,采用这种方法.既保证了仿真的实时性,又提高了模型解算的精确性.     

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     

An approximate dynamic programing approach to the development of heuristics for the scheduling of impatient jobs in a clearing system

A single server is faced with a collection of jobs of varying duration and urgency. Each job has a random lifetime during which it is available for nonpreemptive service. Should a job's lifetime expire before its service begins then it is lost from the system unserved. The goal is to schedule the jobs for service to maximize the expected number served to completion. Two heuristics have been proposed in the literature. One (labeled π^S) operates a static priority among the job classes and works well in a “no premature job loss” limit, whereas the second (π^M) is a myopic heuristic which works well when lifetimes are short. Both can exhibit poor performance for problems at some distance from the regimes for which they were designed. We develop a robustly good heuristic by an approximative approach to the application of a policy improvement step to the asymptotically optimal heuristic π^S, in which we use a fluid model to obtain an approximation for the value function of π^S. The performance of the proposed heuristic is investigated in an extensive numerical study. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

基于蚁群算法的航空弹药需求测算

智能化是现代航空弹药需求与指挥控制系统的发展趋势,如何进行合理快速地调拨航空弹药是系统设计过程中的关键任务之一。为此,提出了依据目标对航空弹药进行选择的策略,利用蚁群算法对战斗目标进行聚类分析,对各类目标进行模糊综合评判,从而确定装备出动方案,依据弹药与装备的关系,对满足既定保障度的弹药需求量建立模型,并计算出满足既定保障度的弹药供应量,为战前对战场态势预估,实现弹药战时及时准确调拨,为作战弹药准备提供依据。     

混合指数分布模型的Bayes分析

针对截尾试验数据的情况,给出了二元混合指数分布模型的平均寿命和可靠性函数的严格的Ｂａｙｅｓ点估计,并运用最大熵准则给出了可靠性函数的近似的Ｂａｙｅｓ置信下限估计。     

飞行器MDO中灵敏度计算的自动微分方法

自动微分方法(ADM)是灵敏度计算的一种新方法,是处理飞行器多学科设计优化中灵敏度分析问题的有力工具。将ADM与估算灵敏度最常用的有限差分方法(FDM)以及与ADM同时期发展起来的另外一种灵敏度计算方法—复变量方法(CVM),从原理上进行了比较,研究了ADM前向模式在Visual C 6.0环境中的实现方法,结合多学科环境中的飞行器设计优化计算实例分析了该模式的优缺点。ADM在科学计算、工程计算等方面有很大的发展空间。     

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     

市场经济体制下火灾隐患的经济学分析及对策

运用经济学的手段阐述了市场经济体制下火灾隐患产生的经济学原因,并从经济学角度提出了解决问题的对策.     

车载定位定向技术研究

为了提高车载定位定向技术的精度,在数据融合理论的基础上,以一种新的角度实现各种技术的组合。针对速率捷联、里程计、高程计等各技术的特点,以速率捷联技术为主,里程计与高程计为辅助,提出各种组合模式。速率捷联发散的高度通道与高程计组合,形成二阶阻尼测高系统,使测高误差降至1 m以下。用加速度计定期校正里程计标度因子,阻尼了速率捷联和里程计不断增大的定位误差,使最大定位误差降到21″。通过对多种车况的仿真可知,这种组合模式使3种技术取长补短,达到了较高的车载定位定向精度。