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171.
This article presents a flexible days‐on and days‐off scheduling problem and develops an exact branch and price (B&P) algorithm to find solutions. The main objective is to minimize the size of the total workforce required to cover time‐varying demand over a planning horizon that may extend up to 12 weeks. A new aspect of the problem is the general restriction that the number of consecutive days on and the number of consecutive days off must each fall within a predefined range. Moreover, the total assignment of working days in the planning horizon cannot exceed some maximum value. In the B&P framework, the master problem is stated as a set covering‐type problem whose columns are generated iteratively by solving one of three different subproblems. The first is an implicit model, the second is a resource constrained shortest path problem, and the third is a dynamic program. Computational experiments using both real‐word and randomly generated data show that workforce reductions up to 66% are possible with highly flexible days‐on and days‐off patterns. When evaluating the performance of the three subproblems, it was found that each yielded equivalent solutions but the dynamic program proved to be significantly more efficient. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 678–701, 2013 相似文献
172.
We study a knapsack problem with an additional minimum filling constraint, such that the total weight of selected items cannot be less than a given threshold. The problem has several applications in shipping, e‐commerce, and transportation service procurement. When the threshold equals the knapsack capacity, even finding a feasible solution to the problem is NP‐hard. Therefore, we consider the case when the ratio α of threshold to capacity is less than 1. For this case, we develop an approximation scheme that returns a feasible solution with a total profit not less than (1 ‐ ε) times the total profit of an optimal solution for any ε > 0, and with a running time polynomial in the number of items, 1/ε, and 1/(1‐α). © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013 相似文献
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174.
本文对瓶颈指派问题给出了一种新的算法,该算法不需要利用最大流算法,而类似于解经典指派问题的匈牙利算法。该算法是一个多项式时间算法,其复杂性为O(n3) 相似文献
175.
Testing provides essential information for managing infectious disease outbreaks, such as the COVID-19 pandemic. When testing resources are scarce, an important managerial decision is who to test. This decision is compounded by the fact that potential testing subjects are heterogeneous in multiple dimensions that are important to consider, including their likelihood of being disease-positive, and how much potential harm would be averted through testing and the subsequent interventions. To increase testing coverage, pooled testing can be utilized, but this comes at a cost of increased false-negatives when the test is imperfect. Then, the decision problem is to partition the heterogeneous testing population into three mutually exclusive sets: those to be individually tested, those to be pool tested, and those not to be tested. Additionally, the subjects to be pool tested must be further partitioned into testing pools, potentially containing different numbers of subjects. The objectives include the minimization of harm (through detection and mitigation) or maximization of testing coverage. We develop data-driven optimization models and algorithms to design pooled testing strategies, and show, via a COVID-19 contact tracing case study, that the proposed testing strategies can substantially outperform the current practice used for COVID-19 contact tracing (individually testing those contacts with symptoms). Our results demonstrate the substantial benefits of optimizing the testing design, while considering the multiple dimensions of population heterogeneity and the limited testing capacity. 相似文献
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177.
章瑞春 《中国人民武装警察部队学院学报》2014,(2):72-73
2009年《消防法》实施以来,消防工作得到了长足的发展,但也反映出一定的问题。分析了《消防法》实施几年来在执法主体力量、概念界定、法律术语等方面中存在的问题,认为应通过合理考虑执法力量状况、理性看待法律条文本身、主动形成执法合作意识等措施,更好地发挥《消防法》在消防监督管理中的重要作用。 相似文献
178.
水中兵器延寿样本的装载可靠度鉴定试验方案 总被引:1,自引:0,他引:1
针对延寿样本子样少,按经典GJB899法对装载可靠度鉴定需要较长的试验时间这一实际情况,提出了一种减少试验时间的Bayes方法.该方法通过挖掘延寿前装载失效率信息,确定先验分布,再开展陆上加速装载试验以增加装载信息,并结合实际装载信息制定了装载可靠度鉴定试验新方案.实例计算表明:在确保鉴定效果的前提下,新方法可在较小的延寿样本条件下快速完成装载可靠度鉴定工作,满足水中兵器延寿工程的实际需要. 相似文献
179.
In this study, we consider a bicriteria multiresource generalized assignment problem. Our criteria are the total assignment load and maximum assignment load over all agents. We aim to generate all nondominated objective vectors and the corresponding efficient solutions. We propose several lower and upper bounds and use them in our optimization and heuristic algorithms. The computational results have shown the satisfactory behaviors of our approaches. © 2014 Wiley Periodicals, Inc. Naval Research Logistics, 61: 621–636, 2014 相似文献
180.
针对嵌入式软件开发的特点,运用独立加载技术实现对嵌入式系统驱动程序代码的独立加载和升级。设备驱动程序独立加载技术打破了多个嵌入式软件模块合编成单个目标文件的传统模式,将各个软件模块进行独立和分离,通过硬件自动扫描引擎自动检测硬件设备,程序加载器构建设备链表和驱动程序链表,并根据配置信息分别加载相应的驱动程序和应用程序,实现多个嵌入式设备驱动程序的独立加载。嵌入式设备驱动程序独立加载技术的研究和应用为各系统组件和应用模块的独立开发以及软件模块动态扩展和独立升级提供了捷径,降低了嵌入式软件协作的人力和时间成本。 相似文献