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   686篇
  免费   127篇
  国内免费   55篇
  2024年   1篇
  2023年   5篇
  2022年   10篇
  2021年   15篇
  2020年   17篇
  2019年   13篇
  2018年   11篇
  2017年   31篇
  2016年   40篇
  2015年   32篇
  2014年   46篇
  2013年   57篇
  2012年   52篇
  2011年   61篇
  2010年   41篇
  2009年   67篇
  2008年   28篇
  2007年   44篇
  2006年   58篇
  2005年   48篇
  2004年   32篇
  2003年   27篇
  2002年   14篇
  2001年   21篇
  2000年   19篇
  1999年   12篇
  1998年   10篇
  1997年   7篇
  1996年   8篇
  1995年   8篇
  1994年   4篇
  1993年   5篇
  1992年   2篇
  1991年   8篇
  1990年   11篇
  1989年   2篇
  1988年   1篇
排序方式: 共有868条查询结果,搜索用时 15 毫秒
851.
基于灰局势决策理论的维修级别分析方法   总被引:6,自引:0,他引:6  
简要介绍了某型无人机维修级别分析及灰局势决策理论的一般概念,针对传统维修级别分析中经济性分析的数据来源广、模型可信度较差的情况,研究基于灰局势决策原理建模的一般方法,通过筛选原始数据并修正计算公式,大大减少了冗余计算,最后运用这一模型对某机载无线电设备进行了经济性分析。  相似文献   
852.
装备保障信息化研究初探   总被引:6,自引:0,他引:6  
装备保障信息化是我军装备保障工作的发展方向,但目前尚无系统理论的指引,现借鉴外军经验,结合从事我军现阶段装备保障信息化工作的体会,较系统地对装备保障信息化的概念、外延、内涵、目标和建设原则与应优先考虑的问题等,作出了探索性地阐述,以期推动我军装备保障信息化理论的形成与发展.  相似文献   
853.
We present two frameworks for designing random search methods for discrete simulation optimization. One of our frameworks is very broad (in that it includes many random search methods), whereas the other one considers a special class of random search methods called point‐based methods, that move iteratively between points within the feasible region. Our frameworks involve averaging, in that all decisions that require estimates of the objective function values at various feasible solutions are based on the averages of all observations collected at these solutions so far. Also, the methods are adaptive in that they can use information gathered in previous iterations to decide how simulation effort is expended in the current iteration. We show that the methods within our frameworks are almost surely globally convergent under mild conditions. Thus, the generality of our frameworks and associated convergence guarantees makes the frameworks useful to algorithm developers wishing to design efficient and rigorous procedures for simulation optimization. We also present two variants of the simulated annealing (SA) algorithm and provide their convergence analysis as example application of our point‐based framework. Finally, we provide numerical results that demonstrate the empirical effectiveness of averaging and adaptivity in the context of SA. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
854.
In this article, we study item shuffling (IS) problems arising in the logistics system of steel production. An IS problem here is to optimize shuffling operations needed in retrieving a sequence of steel items from a warehouse served by a crane. There are two types of such problems, plate shuffling problems (PSP) and coil shuffling problems (CSP), considering the item shapes. The PSP is modeled as a container storage location assignment problem. For CSP, a novel linear integer programming model is formulated considering the practical stacking and shuffling features. Several valid inequalities are constructed to accelerate the solving of the models. Some properties of optimal solutions of PSP and CSP are also derived. Because of the strong NP‐hardness of the problems, we consider some special cases of them and propose polynomial time algorithms to obtain optimal solutions for these cases. A greedy heuristic is proposed to solve the general problems and its worst‐case performances on both PSP and CSP are analyzed. A tabu search (TS) method with a tabu list of variable length is proposed to further improve the heuristic solutions. Without considering the crane traveling distance, we then construct a rolling variable horizon heuristic for the problems. Numerical experiments show that the proposed heuristic algorithms and the TS method are effective. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
855.
Scheduling IT projects and assigning the project work to human resources are an important and common tasks in almost any IT service company. It is particularly complex because human resources usually have multiple skills. Up to now only little work has considered IT‐specific properties of the project structure and human resources. In this article, we present an optimization model that simultaneously schedules the activities of multiple IT projects with serial network structures and assigns the project work to multiskilled internal and external human resources with different efficiencies. The goal is to minimize costs. We introduce a metaheuristic that decomposes the problem into a binary scheduling problem and a continuous staffing problem where the latter is solved efficiently by exploiting its underlying network structure. For comparison, we solve the mixed–binary linear program with a state–of–the–art commercial solver. The impacts of problem parameters on computation time and solution gaps between the metaheuristic and the solver are assessed in an experimental study. Our results show that the metaheuristic provides very favorable results in considerable less time than the solver for midsize problems. For larger problems, it shows a similar performance while the solver fails to return feasible solutions. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 59: 111–127, 2012  相似文献   
856.
Characteristically, a small subset of operational problems admit risk neutrality when contingent claims methodology were used in their analysis. That is, for the majority of manufacturing and production problems, operating cash flows are not directly linked to prices of traded assets. However, to the extent that correlations can be estimated, the methodology's applicability to a broader set of operational problems is supported. Our article addresses this issue with the objective of extending the use of contingent claims techniques to a larger set of operational problems. In broad terms, this objective entails a partial equilibrium approach to the problem of valuing uncertain cash flows. To this end, we assume risk aversion and cast our approach within Merton's intertemporal capital asset pricing model. In this context, we formulate a “generic” production valuation model that is framed as an exercise in stochastic optimal control. The model is versatile in its characterization and can easily be adapted to accommodate a wide‐ranging set of risk‐based operational problems where the underlying sources of uncertainty are not traded. To obtain results, the model is recast as a stochastic dynamic program to be solved numerically. The article addresses a number of fundamental issues in the analysis risk based decision problems in operations. First, in the approach provided, decisions are analyzed under a properly defined risk structure. Second, the process of analysis leads to suitably adjusted probability distributions through which, appropriately discounted expectations are derived. Third, through consolidating existing concepts into a standard and adaptable framework, we extend the applicability of contingent claims methodology to a broader set of operational problems. The approach is advantageous as it obviates the need for exogenously specifying utility functions or discount rates.© 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011  相似文献   
857.
鉴于某型高炮武器系统的复杂性,考虑采用多数据信息融合的方式来实现其效能评估。针对传统D-S理论在融合冲突信息时的局限性,提出一种基于数据信息确定证据权重的改进D-S理论,并将其用于某型高炮武器系统的作战效能评估。应用示例表明改进D-S理论相比其他算法更加优越。  相似文献   
858.
为了解决提高航母编队防空作战效能的问题,运用决策树方法分析航母编队防空作战指挥网是一种新方法。先分析航母编队的指挥机构,分析决策群指、作战平台与任务之间的关系。描述了编队协同网和编队指挥关系网,建立了编队指挥关系网的数学模型,采用决策树方法求解该数学模型,给出了编队指挥关系网的设计算法,通过实例分析了算法的计算过程,对结果进行输出。结论:预警机与远程巡逻机战术群是指挥关系网的最高决策点。这些工作为设计和优化航母编队舰机协同防空作战指挥网提供了一定的理论基础。  相似文献   
859.
政治理论课是党在军队开展的政治工作的重要组成部分,是军队思想政治教育的主渠道、主阵地。作为没有部队经历的文职人员,提高政治理论课教学能力,要从坚定理论信仰、提升知识水平、拓宽沟通渠道等方面下功夫。  相似文献   
860.
教师教学不能只给学生灌输知识,而应该引导学生用自己的头脑来建构知识。建构主义理论正是基于此,提出了合作学习、支架式教学等方式,并取得良好成效,从而成为了"教育心理学的一场变革"。本文在阐述建构主义理论的学习观和教学观的基础上,重点探讨这场革命中提出的新观点和新理念对于高校普通心理学教学模式以及教学方法的启示,以期能够在普通心理学的实际教学中找到新突破,提高学生的学习效果和教师的教学效果。  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