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   533篇
  免费   123篇
  国内免费   67篇
  2023年   1篇
  2022年   1篇
  2021年   6篇
  2020年   8篇
  2019年   15篇
  2018年   8篇
  2017年   34篇
  2016年   36篇
  2015年   30篇
  2014年   34篇
  2013年   81篇
  2012年   38篇
  2011年   37篇
  2010年   30篇
  2009年   47篇
  2008年   40篇
  2007年   48篇
  2006年   51篇
  2005年   40篇
  2004年   36篇
  2003年   22篇
  2002年   18篇
  2001年   18篇
  2000年   14篇
  1999年   6篇
  1998年   4篇
  1997年   3篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   3篇
  1991年   1篇
  1990年   4篇
  1989年   3篇
  1988年   1篇
排序方式: 共有723条查询结果,搜索用时 15 毫秒
311.
陆军防空兵自动化指挥系统已作为防空作战效能“倍增器”列入国家军装武器发展规划,并在近期可能交付防空部队使用。这一新装备、新技术的出现和发展必然会引起防空作战指挥的变化。在分析防空兵指挥自动化对防空作战指挥影响的基础上,对如何发挥防空兵自动化指挥的防空作战效能和防空兵指挥自动化需迫切解决的一些问题加以探讨。  相似文献   
312.
本文阐述了社会系统运行理论的初步框架,并以其分析社会系统的组织化状态与政策在其自组织中的功能;在剖析不同类型经济系统利弊的基础上,提出了我国现阶段政策制定的基本思路。  相似文献   
313.
We consider the problem of service rate control of a single‐server queueing system with a finite‐state Markov‐modulated Poisson arrival process. We show that the optimal service rate is nondecreasing in the number of customers in the system; higher congestion levels warrant higher service rates. On the contrary, however, we show that the optimal service rate is not necessarily monotone in the current arrival rate. If the modulating process satisfies a stochastic monotonicity property, the monotonicity is recovered. We examine several heuristics and show where heuristics are reasonable substitutes for the optimal control. None of the heuristics perform well in all the regimes and the fluctuation rate of the modulating process plays an important role in deciding the right heuristic. Second, we discuss when the Markov‐modulated Poisson process with service rate control can act as a heuristic itself to approximate the control of a system with a periodic nonhomogeneous Poisson arrival process. Not only is the current model of interest in the control of Internet or mobile networks with bursty traffic, but it is also useful in providing a tractable alternative for the control of service centers with nonstationary arrival rates. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 661–677, 2013  相似文献   
314.
In this article, we study a queueing system serving multiple classes of customers. Each class has a finite‐calling population. The customers are served according to the preemptive‐resume priority policy. We assume general distributions for the service times. For each priority class, we derive the steady‐state system size distributions at departure/arrival and arbitrary time epochs. We introduce the residual augmented process completion times conditioned on the number of customers in the system to obtain the system time distribution. We then extend the model by assuming that the server is subject to operation‐independent failures upon which a repair process with random duration starts immediately. We also demonstrate how setup times, which may be required before resuming interrupted service or picking up a new customer, can be incorporated in the model. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013  相似文献   
315.
无人机集群作战概念及关键技术分析   总被引:3,自引:0,他引:3  
无人机集群作战正在从概念走向雏形.文章总结了国外无人机集群作战概念的发展,分析了无人机集群作战的主要关键技术,包括大规模无人机管理与控制、多无人机自主编队飞行、集群感知与态势共享、集群突防与攻击、集群作战任务控制站等技术,并展望了未来无人机集群协同搜索、协同干扰、协同攻击、协同察/打、集群对抗等作战应用.  相似文献   
316.
舆论战作为信息时代一种独立而重要的作战样式,是一种渗透力、攻击力、威慑力很强的特殊武器,是海上维权斗争行动的重要组成部分.文章对开展海上雏权斗争舆论战的紧迫性进行了分析,归纳总结了海上维权斗争舆论战的特点,探索了开展海上维权斗争舆论战的对策.  相似文献   
317.
为解决疏通航道反水雷作战中的航道选择问题,根据水雷位置确定条件下的反水雷作战特点,运用多目标优化理论建立了与疏通时间最少和雷区航道最短等价的清除水雷数最少和航道倾角绝对值最小疏通航道优化模型。根据疏通航道反水雷作战实际,通过基于完全分层法的单目标模型解算流程、方法,得到优化参数,较好地满足了疏通航道反水雷作战需求。  相似文献   
318.
319.

As we enter the 21st Century, technologies originally developed for defense purposes such as computers and satellite communications appear to have become a driving force behind economic growth in the United States. Paradoxically, almost all previous econometric models suggest that the largely defense‐oriented federal industrial R&;D funding that helped create these technologies had no discernible effect on U.S. industrial productivity growth. This paper addresses this paradox by stressing that defense procurement as well as federal R&;D expenditures were targeted to a few narrowly defined manufacturing sub‐sectors that produced high tech weaponry. Analysis employing data from the NBER Manufacturing Productivity Database and the BEA’ s Input Output tables then demonstrates that defense procurement policies did have significant effects on the productivity performance of disaggregated manufacturing industries because of a process of procurement‐driven technological change.  相似文献   
320.
In this paper we develop an empirical model for transnational terrorist activity for a panel consisting of 139 countries over the period 1985–1998. Essentially, we attempt to sketch the profile of the average terrorist attack venue. Our findings suggest that the terrorist attack venue is, on average, characterized by low economic openness, high demographic stress, and a high level of international disputes. Furthermore, we document a strong regional component suggesting the presence of infectious contagion on a spatial level. Our results also support the presence of addictive contagion captured by a strong autoregressive component in each country’s terrorist activity. Finally, we find a weak statistical link between the level of democracy and terrorist activity, although the level of democracy is a significant determinant of the potential under‐reporting bias of terrorist activity.  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