一类带配送中心运输问题的容量扩张模型研究

运输问题一般采用表上作业法来解决,考虑一类带配送中心的运输问题,若仍采用表上作业法,会使问题复杂化.文中采用一种构造辅助网络的方法:在运输网络中将每个配送中心均拆分成两个点,连接两点形成新弧,构造出新的网络,并给每条弧赋予参数,将此类运输问题转换为最小费用流模型来解决,可以使问题模型和运算简单化.在此基础上,考虑运输网络中配送中心和边的容量扩张问题.     

基于移动Agent的特定数值求解算法研究

在分布式环境下,运用移动Agent技术实现大型复杂系统研究中经常使用的特定数值算法求解,可显著提高计算效率。以分支定界法为例,介绍了其设计思想和实践步骤,并对算法的时间复杂度进行了分析。     

影响合成旅实战化装备保障能力问题与对策

针对“跨越-2020库尔勒B”演习中,装备保障矛盾问题突出、维修保障难度大的情况,从装备保障力量发展不均衡、保障分队自身保障存在不足、人才储备弱的影响;高温、潮湿、风沙、高海拔等周边环境恶劣程度的影响;器材筹措效率高低、器材储供管理的好坏、器材利用率高低的影响;指挥控制链路关系、感知战场态势、控制战场节奏的影响四个方面存在的问题,对解决提出的问题进行了思考,从固强补弱装备保障力量、积极适应战场周边环境、优化器材储供管理和筹措渠道、提高装备保障指挥控制能力等方面着手,结合演训地区实际装备保障存在矛盾问题出发,探索和研究实战化训练中装备保障的对策措施,以期为部队实战化装备保障提供借鉴。     

惯性导航系统故障诊断的不确定性问题研究

针对构造惯性导航系统 ( INS)故障诊断所面临的确定性和不确定性问题 ,提出了基于模糊集理论的诊断方法 ,并给出诊断系统自动获取不确定性证据和确定性证据隶属度的方法及函数 .认为对于确定性证据和不确定性证据可以用统一的方法和原则来处理 ,并建立了两类证据的实用数学模型     

超视距多目标攻击排序及火力分配建模与解算

针对未来超视距空战条件下的多目标攻击排序和制导武器火力分配问题,提出了一种用以评估超视距空战作战效能的综合优势指数法;当目标数多于攻击机数时,通过构造综合优势矩阵,将非平衡指派问题转化为平衡指派问题,并建立了多目标攻击排序的0-1规划模型,该模型可解决对多个目标同时攻击的排序问题;以2对8攻击排序为例,利用求解线性规划软件Lindo6.0进行解算。最后,建立了1对4攻击火力分配的非线性规划模型,并利用求解非线性规划软件Lingo5.0进行解算。计算结果验证了建模的合理性和运用Lindo、Lingo软件求解较大规模目标攻击排序和火力分配问题的实时性。     

航路规划中大地主题解算的简化方法

介绍了大地主题解算的精确公式:Bowring公式,给出了三种大地主题解算的简化方法,包括:椭球体到圆球体、椭球面到圆球面以及椭球面到平面的简化方法,并分析了各种简化方法的误差大小。     

Heuristics for the multi‐resource generalized assignment problem

The well‐known generalized assignment problem (GAP) involves the identification of a minimum‐cost assignment of tasks to agents when each agent is constrained by a resource in limited supply. The multi‐resource generalized assignment problem (MRGAP) is the generalization of the GAP in which there are a number of different potentially constraining resources associated with each agent. This paper explores heuristic procedures for the MRGAP. We first define a three‐phase heuristic which seeks to construct a feasible solution to MRGAP and then systematically attempts to improve the solution. We then propose a modification of the heuristic for the MRGAP defined previously by Gavish and Pirkul. The third procedure is a hybrid heuristic that combines the first two heuristics, thus capturing their relative strengths. We discuss extensive computational experience with the heuristics. The hybrid procedure is seen to be extremely effective in solving MRGAPs, generating feasible solutions to more than 99% of the test problems and consistently producing near‐optimal solutions. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 468–483, 2001     

充分发展湍流管道内壁边界的红外定量识别

基于导热的管道内壁边界识别已发展成熟,但更贴合实际的湍流管道内壁边界的定量识别尚未见报道。通过关联COMSOL和MATLAB,利用有限元方法和Levenberg-Marquardt算法对二维轴对称充分发展的湍流管道内壁边界形状的稳态识别进行研究。数值实验证明了本方法的有效性。结果表明,在含内壁缺陷的湍流管道中,外壁最大温差和由缺陷引起的绝对温差并不是同步增加的;在进行内壁边界反问题识别时,由于绝对温差中负增长的出现,绝对温差越大,识别结果未必越好;识别精度在不规则内壁终点处略微变差。     

Bi‐objective missile rescheduling for a naval task group with dynamic disruptions

This paper considers the rescheduling of surface‐to‐air missiles (SAMs) for a naval task group (TG), where a set of SAMs have already been scheduled to intercept a set of anti‐ship missiles (ASMs). In missile defense, the initial engagement schedule is developed according to the initial state of the defensive and attacking units. However, unforeseen events may arise during the engagement, creating a dynamic environment to be handled, and making the initial schedule infeasible or inefficient. In this study, the initial engagement schedule of a TG is assumed to be disrupted by the occurrence of a destroyed ASM, the breakdown of a SAM system, or an incoming new target ASM. To produce an updated schedule, a new biobjective mathematical model is formulated that maximizes the no‐leaker probability value for the TG and minimizes the total deviation from the initial schedule. With the problem shown to be NP‐hard, some special cases are presented that can be solved in polynomial time. We solve small size problems by the augmented ? ‐ constraint method and propose heuristic procedures to generate a set of nondominated solutions for larger problems. The results are presented for different size problems and the total effectiveness of the model is evaluated.     

Optimizing natural gas pipeline transmission with nonuniform elevation: A new initialization approach

In this paper, we develop an iterative piecewise linear approximation approach with a novel initialization method to solve natural gas pipeline transmission problems with the nonuniform network elevation. Previous approaches, such as energy minimization methods, cannot be applied to solve problems with the nonuniform network elevation because they exclude pressure range constraints, and thus provide solutions far from optimum. We propose a new initialization model that considers pressure range constraints and improves the optimality of the solutions and the computational efficiency. Furthermore, we extend the energy minimization methods and provide the necessary conditions under which the extended methods operate in networks with the nonuniform elevation. We test the performances of the methods with previously reported pipeline networks from the literature, with the open data set GasLib, and with our industrial collaborator. The initialization approach is shown to be more efficient than the method with fixed initial breakpoints. The newly proposed initialization approach generates solutions with a higher accuracy than the extended energy minimization methods, especially in large‐size networks. The proposed method has been applied to natural gas transmission planning by the China National Petroleum Corporation and has brought a direct profit increase of 330 million U.S. dollars in 2015‐2017.