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   319篇
  免费   14篇
  国内免费   1篇
  2021年   5篇
  2019年   7篇
  2018年   4篇
  2017年   5篇
  2016年   5篇
  2015年   5篇
  2014年   6篇
  2013年   69篇
  2012年   5篇
  2011年   5篇
  2010年   5篇
  2009年   3篇
  2008年   4篇
  2007年   4篇
  2006年   6篇
  2003年   3篇
  2002年   3篇
  2000年   3篇
  1998年   2篇
  1997年   5篇
  1996年   7篇
  1995年   2篇
  1994年   6篇
  1993年   9篇
  1992年   6篇
  1991年   7篇
  1990年   2篇
  1989年   7篇
  1988年   7篇
  1987年   4篇
  1986年   6篇
  1985年   8篇
  1984年   5篇
  1983年   4篇
  1982年   5篇
  1981年   4篇
  1980年   8篇
  1979年   7篇
  1978年   8篇
  1977年   2篇
  1976年   7篇
  1975年   10篇
  1974年   6篇
  1973年   8篇
  1972年   5篇
  1971年   4篇
  1970年   5篇
  1969年   4篇
  1968年   5篇
  1967年   3篇
排序方式: 共有334条查询结果,搜索用时 15 毫秒
131.
This paper presents an alternative approach for analyzing international competition and alliances as rent‐seeking contests that are able to capture the impure public good nature of defense spending. Two‐country Cournot and Stackelberg games are considered and comparative static results derived. A three‐country model is investigated, and alliance behavior is explored in the context of this rent‐seeking model. The conjecture that an alliance may become less effective if the allies’ interests become more closely aligned is verified. Finally, the model is generalized, and a Nash‐Cournot equilibrium is computed.  相似文献   
132.
Public opinion survey responses regarding the desirability of changes in defense spending can be compressed into a single variable, the public opinion balance, which, when accompanied by a control variable measuring the proportion of responses in the “residuum” (no opinion or keep the status quo), permits an accurate prediction of subsequent changes in the rate of change of U.S. defense outlays from the mid‐1960s through the 1980s. This finding cannot be interpreted as a simple case of “the public got what it wanted,” however, because public opinion was not autonomous or spontaneous, and defense decision makers themselves played a central role in shaping public opinion.  相似文献   
133.
Conflict resolution processes must meet certain prerequisites and conditions. Unless the warring parties or the mediators meet, it will be difficult to find lasting and just solutions to the conflicts in the Horn (Djibouti, Eritrea and Ethiopia, and Somalia). Most of these conflicts have ethnic or religious components and also have a lot do with the nature of the government institutions and the power distribution among the communities within these states. Identifying the main causes of the conflict and the issues involved in each country is a very necessary first step toward peace. Secondly, conditions have to be identified that would make the current peace agreements work. This includes identifying the specific problems faced by the parties involved; ascertaining the validity of the mechanisms through which the problems will be overcome; and planning how the agreements will be maintained. The knowledge that mediators have about the conflict is often as important as the actual meeting of parties at the negotiation table. This article also evaluates the peace initiatives underway in the Horn and attempts to identify the apparent reasons that prevented their implementation.  相似文献   
134.
135.
136.
137.
An analysis of US assessments of Germany's development of armored warfare illustrates the problems that intelligence agencies face as they attempt to understand military innovation. The covert nature of German Army's tank research in the years immediately following World War I limited the number of indicators of Berlin's interest in armored warfare. Similarly, the United States possessed at best a fragmentary picture of German experimentation with armor. By the outbreak of World War II, however, US military attaches had nonetheless developed an accurate understanding of German concepts of armored warfare. If the United States is to avoid strategic surprise in the future, it must cultivate intelligence sources and employ considerably different methods from those of the Cold War.  相似文献   
138.
139.
This paper presents a modified analytical model to evaluate the trajectories of various lift separation sabot configurations. The aerodynamic forces acting on the sabot surfaces during a supersonic flight are modeled in the present analytical model by incorporating the pressures on the windward side of the sabot due to the detached/attached shock and its reflections and then integrated using the 3-DoF dynamical equations. The trajectory and the aerodynamic coefficients were obtained for these config-urations at a projectile Mach number of 3. The sabot configurations, which include two new designs, are compared with each other and with the conventional free flight trajectory data of the conventional sabots. The mechanical interaction between the sabot and projectile is also addressed in the present work. The comparison shows that the new designs with the aerodynamic surfaces close to the center of gravity, lift-off from the projectile with minimal mechanical interaction compared to a conventional sabot.  相似文献   
140.
In this paper we consider the problem of minimizing the costs of outsourcing warranty repairs when failed items are dynamically routed to one of several service vendors. In our model, the manufacturer incurs a repair cost each time an item needs repair and also incurs a goodwill cost while an item is awaiting and undergoing repair. For a large manufacturer with annual warranty costs in the tens of millions of dollars, even a small relative cost reduction from the use of dynamic (rather than static) allocation may be practically significant. However, due to the size of the state space, the resulting dynamic programming problem is not exactly solvable in practice. Furthermore, standard routing heuristics, such as join‐the‐shortest‐queue, are simply not good enough to identify potential cost savings of any significance. We use two different approaches to develop effective, simply structured index policies for the dynamic allocation problem. The first uses dynamic programming policy improvement while the second deploys Whittle's proposal for restless bandits. The closed form indices concerned are new and the policies sufficiently close to optimal to provide cost savings over static allocation. All results of this paper are demonstrated using a simulation study. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005  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