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1.
We seek dynamic server assignment policies in finite‐capacity queueing systems with flexible and collaborative servers, which involve an assembly and/or a disassembly operation. The objective is to maximize the steady‐state throughput. We completely characterize the optimal policy for a Markovian system with two servers, two feeder stations, and instantaneous assembly and disassembly operations. This optimal policy allocates one server per station unless one of the stations is blocked, in which case both servers work at the unblocked station. For Markovian systems with three stations and instantaneous assembly and/or disassembly operations, we consider similar policies that move a server away from his/her “primary” station only when that station is blocked or starving. We determine the optimal assignment of each server whose primary station is blocked or starving in systems with three stations and zero buffers, by formulating the problem as a Markov decision process. Using this optimal assignment, we develop heuristic policies for systems with three or more stations and positive buffers, and show by means of a numerical study that these policies provide near‐optimal throughput. Furthermore, our numerical study shows that these policies developed for assembly‐type systems also work well in tandem systems. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008  相似文献   
2.
针对航空发动机修理工厂大修能力难以评估的问题,提出了航空发动机大修能力评估方法。分析了航空发动机大修生产过程;根据航空发动机大修生产工作特点,建立了基于生产职能分解的航空发动机大修能力评估指标体系,构建出基于熵权和灰色聚类的评估指标赋权模型;结合实例验证了方法的正确性和实用性。  相似文献   
3.
We study a parallel machine scheduling problem, where a job j can only be processed on a specific subset of machines Mj, and the Mj subsets of the n jobs are nested. We develop a two‐phase heuristic for minimizing the total weighted tardiness subject to the machine eligibility constraints. In the first phase, we compute the factors and statistics that characterize a problem instance. In the second phase, we propose a new composite dispatching rule, the Apparent Tardiness Cost with Flexibility considerations (ATCF) rule, which is governed by several scaling parameters of which the values are determined by the factors obtained in the first phase. The ATCF rule is a generalization of the well‐known ATC rule which is very widely used in practice. We further discuss how to improve the dispatching rule using some simple but powerful properties without requiring additional computation time, and the improvement is quite satisfactory. We apply the Sequential Uniform Design Method to design our experiments and conduct an extensive computational study, and we perform tests on the performance of the ATCF rule using a real data set from a large hospital in China. We further compare its performance with that of the classical ATC rule. We also compare the schedules improved by the ATCF rule with what we believe are Near Optimal schedules generated by a general search procedure. The computational results show that especially with a low due date tightness, the ATCF rule performs significantly better than the well‐known ATC rule generating much improved schedules that are close to the Near Optimal schedules. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 249–267, 2017  相似文献   
4.
Design and management of complex systems with both integer and continuous decision variables can be guided using mixed‐integer optimization models and analysis. We propose a new mixed‐integer black‐box optimization (MIBO) method, subspace dynamic‐simplex linear interpolation search (SD‐SLIS), for decision making problems in which system performance can only be evaluated with a computer black‐box model. Through a sequence of gradient‐type local searches in subspaces of solution space, SD‐SLIS is particularly efficient for such MIBO problems with scaling issues. We discuss the convergence conditions and properties of SD‐SLIS algorithms for a class of MIBO problems. Under mild conditions, SD‐SLIS is proved to converge to a stationary solution asymptotically. We apply SD‐SLIS to six example problems including two MIBO problems associated with petroleum field development projects. The algorithm performance of SD‐SLIS is compared with that of a state‐of‐the‐art direct‐search method, NOMAD, and that of a full space simplex interpolation search, Full‐SLIS. The numerical results suggest that SD‐SLIS solves the example problems efficiently and outperforms the compared methods for most of the example cases. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 305–322, 2017  相似文献   
5.
为提升指挥控制系统应对变化的能力、解决当前指挥控制系统敏捷演化的难点问题,提出了基于知识的敏捷指挥控制系统演化方法。结合领域知识,对上下文和指挥控制规则进行建模,给出了实现敏捷指挥控制的知识推理方法和基于知识的敏捷指挥控制系统演化机制,为指挥控制系统敏捷演化奠定了基础。最后,试验验证该方法能有效提升指挥控制系统敏捷演化水平。  相似文献   
6.
法治的实现有赖于法治要素的具备,而正当程序有助于法治要素的满足。法治社会应具有的正当程序理念是:正当程序是对人权的尊重和保护,是实现正义的重要途径,程序正义优先于实体正义。  相似文献   
7.
秘密监听对公民宪法所保障的权利和自由产生了威胁,但是对侦查日益智能化的犯罪又是不可或缺的证据收集方式。从适应刑事庭审方式对证据要求的角度对秘密监听加以规范,使其以最小化的侵犯公民权利、自由的方式,达到证据收集效率的最优化,使以秘密监听收集方式获得的证据不致因违法而被排除在法庭之外,就必须从理论上解决秘密监听的法理依据及其密切相关的强迫自证其罪与拒绝证言权等问题,并使其能够最终成为定案的依据。  相似文献   
8.
高气压非平衡等离子体是当今世界经济、军事强国竞相研究的焦点,涉及工业、军事的高能物质(活性粒子)加工及其辐射的等离子体源及反应器(室)。目前,高气压非平衡等离子体及其源的研究局限于弱(电场)电离放电范畴,存在等离子体浓度低、能耗甚高和体积庞大等问题。为此,研究外加非均匀强电场、空间电荷形成的本征电场对离子的作用力及其运动规律,以便解决形成高浓度等离子体的方法及离子从强电场束缚中引出去的问题,为研制强电离放电非平衡等离子体源提供了理论基础及加工方法,此源外输的等离子体束的浓度有望达到1014/cm3。等离子体源及反应器可以做到微型化,每立方厘米有效放电体积处理气量高达15m3/h。它的体积、能耗、一次造价、运行成本等也将成万倍地降低,解决了等离子体工程化的现存问题;也能解决困扰世界各军事强国的飞行器等离子体隐身、减阻及天线的应用理论与方法问题。  相似文献   
9.
While there has been significant previous literature on inventory transshipment, most research has focused on the dealers' demand filling decision (when to fill transshipment requests from other dealers), ignoring the requesting decision (when to send transshipment requests to other dealers). In this paper we develop optimal inventory transshipment policies that incorporate both types of decisions. We consider a decentralized system in which the dealers are independent of the manufacturer and of each other. We first study a network consisting of a very large number of dealers. We prove that the optimal inventory and transshipment decisions for an individual dealer are controlled by threshold rationing and requesting levels. Then, in order to study the impact of transshipment among independent dealers in a smaller dealer network, we consider a decentralized two‐dealer network and use a game theoretic approach to characterize the equilibrium inventory strategies of the individual dealers. An extensive numerical study highlights the impact of the requesting decision on the dealers' equilibrium behavior in a decentralized setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006  相似文献   
10.
基于免疫FNN算法的加热炉炉温优化控制   总被引:1,自引:0,他引:1       下载免费PDF全文
针对复杂钢坯加热过程,提出了一种免疫克隆进化模糊神经网络(ICE-FNN)控制算法。首先根据现场样本数据建立过程神经网络模型;然后基于该模型,采用模糊神经网络控制器(FNNC)规则优化算法,确定FNNC的最佳规则数;最后由FNNC的规则优化所得参数构造初始种群的一个解,采用免疫克隆进化(ICE)算法对FNNC参数优化。该算法具有全局寻优和局部求精能力,仿真结果证实了其有效性。  相似文献   
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