首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   146篇
  免费   42篇
  国内免费   4篇
  2022年   2篇
  2020年   7篇
  2019年   3篇
  2018年   3篇
  2017年   13篇
  2016年   10篇
  2015年   7篇
  2014年   11篇
  2013年   21篇
  2012年   8篇
  2011年   13篇
  2010年   8篇
  2009年   14篇
  2008年   9篇
  2007年   14篇
  2006年   9篇
  2005年   12篇
  2004年   6篇
  2003年   5篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1999年   6篇
  1998年   3篇
  1992年   1篇
  1990年   1篇
排序方式: 共有192条查询结果,搜索用时 15 毫秒
71.
通过火灾燃烧产物及灭火产物对环境的一些负面影响,提出了"绿色消防"的要求。  相似文献   
72.
针对多约束QoS多播路由的NP-Complete特性,提出一种可控的多播树分解与合并策略,使多播树的生成在兼顾低费用的同时具有多样性,有效克服多播路由优化的局部极值问题。基于该策略设计蚁群算法,分解蚂蚁种群为与多播目标点相对应的蚂蚁子群,引入基于“死点”惩罚和多播树奖惩的信息素更新机制,提高了算法的收敛速度。仿真实验表明,该方法能有效地解决QoS多播路由问题,且随着网络规模的增大保持了良好的性能。  相似文献   
73.
在不影响溴乙烷正常产率的前提下,改变原料量和加料方法,设计出制备溴乙烷的半微型实验新方案,与常量制备法相比,具有节约药品,操作安全省时,污染小等优点,在教学实践中经反复检验,符合半微型化学实验要求,是值得推广的新实验方案。  相似文献   
74.
It is generally recognized that the first model involving job scheduling was presented by Selmer Johnson and published in the inaugural issue of Naval Research Logistics Quarterly (NRLQ) in 1954. NRLQ also published another seminal scheduling paper by Wayne E. Smith a short time later. In the present paper, we discuss the contribution of NRLQ and the role of the Office of Naval Research in the development of the scheduling literature during the first decade (1954–1963). We also provide a critical analysis of the papers by Johnson and Smith. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 335–344, 2015  相似文献   
75.
This article describes a polynomial transformation for a class of unit‐demand vehicle routing problems, named node‐balanced routing problems (BRP), where the number of nodes on each route is restricted to be in an interval such that the workload across the routes is balanced. The transformation is general in that it can be applied to single or multiple depot, homogeneous or heterogeneous fleet BRPs, and any combination thereof. At the heart of the procedure lies transforming the BRP into a generalized traveling salesman problem (TSP), which can then be transformed into a TSP. The transformed graph exhibits special properties which can be exploited to significantly reduce the number of arcs, and used to construct a formulation for the resulting TSP that amounts to no more than that of a constrained assignment problem. Computational results on a number of instances are presented. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 370–387, 2015  相似文献   
76.
This study analyzes the determinants of arms production in 15 countries using annual panel data from 1997 to 2002. The results suggest that real GDP per capita, military expenditures, arms exports, and arms imports are positively related to arms production.  相似文献   
77.
移动汇聚节点调度是传感器网络中一个新的研究热点.通过建立一个普适的多目标优化模型,提出了贴近实际的汇聚节点循环路径规划模型,采用以连续时间离散化为理论基础的时域-空域转化方法,将时域中的优化模型无损地转至空域中,从而大大减少了所涉及的变量数量,降低了求解的复杂度.通过实验可以看出,调度移动汇聚节点可以有效扩展网络的生命周期.  相似文献   
78.
We study a problem of scheduling products on the same facility, which is motivated by a car paint shop. Items of the same product are identical. Operations on the items are performed sequentially in batches, where each batch is a set of operations on the same product. Some of the produced items are of the required good quality and some items can be defective. Defectiveness of an item is determined by a given simulated function of its product, its preceding product, and the position of its operation in the batch. Defective items are kept in a buffer of a limited capacity, and they are then remanufactured at the same facility. A minimum waiting time exists for any defective item before its remanufacturing can commence. Each product has a sequence independent setup time which precedes its first operation or its operation following an operation of another product. A due date is given for each product such that all items of the same product have the same due date and the objective is to find a schedule which minimizes maximum lateness of product completion times with respect to their due dates. The problem is proved NP‐hard in the strong sense, and a heuristic Group Technology (GT) solution approach is suggested and analyzed. The results justify application of the GT approach to scheduling real car paint shops with buffered rework. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 458–471, 2014  相似文献   
79.
In the classical EPQ model with continuous and constant demand, holding and setup costs are minimized when the production rate is no larger than the demand rate. However, the situation may change when demand is lumpy. We consider a firm that produces multiple products, each having a unique lumpy demand pattern. The decision involves determining both the lot size for each product and the allocation of resources for production rate improvements among the products. We find that each product's optimal production policy will take on only one of two forms: either continuous production or lot‐for‐lot production. The problem is then formulated as a nonlinear nonsmooth knapsack problem among products determined to be candidates for resource allocation. A heuristic procedure is developed to determine allocation amounts. The procedure decomposes the problem into a mixed integer program and a nonlinear convex resource allocation problem. Numerical tests suggest that the heuristic performs very well on average compared to the optimal solution. Both the model and the heuristic procedure can be extended to allow the company to simultaneously alter both the production rates and the incoming demand lot sizes through quantity discounts. Extensions can also be made to address the case where a single investment increases the production rate of multiple products. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004.  相似文献   
80.
We consider queueing systems with multiple classes of customers and heterogeneous servers where customers have the flexibility of being processed by more than one server and servers possess the capability of processing more than one customer class. We provide a unified framework for the modeling and analysis of these systems under arbitrary customer and server flexibility and for a rich set of control policies that includes customer/server‐specific priority schemes for server and customer selection. We use our models to generate several insights into the effect of system configuration and control policies. In particular, we examine the relationship between flexibility, control policies and throughput under varying assumptions for system parameters. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号