全文获取类型
收费全文 | 625篇 |
免费 | 75篇 |
国内免费 | 83篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 23篇 |
2017年 | 40篇 |
2016年 | 38篇 |
2015年 | 26篇 |
2014年 | 42篇 |
2013年 | 65篇 |
2012年 | 50篇 |
2011年 | 52篇 |
2010年 | 15篇 |
2009年 | 42篇 |
2008年 | 23篇 |
2007年 | 45篇 |
2006年 | 73篇 |
2005年 | 52篇 |
2004年 | 35篇 |
2003年 | 26篇 |
2002年 | 19篇 |
2001年 | 25篇 |
2000年 | 14篇 |
1999年 | 18篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有783条查询结果,搜索用时 703 毫秒
741.
This paper considers the rescheduling of surface‐to‐air missiles (SAMs) for a naval task group (TG), where a set of SAMs have already been scheduled to intercept a set of anti‐ship missiles (ASMs). In missile defense, the initial engagement schedule is developed according to the initial state of the defensive and attacking units. However, unforeseen events may arise during the engagement, creating a dynamic environment to be handled, and making the initial schedule infeasible or inefficient. In this study, the initial engagement schedule of a TG is assumed to be disrupted by the occurrence of a destroyed ASM, the breakdown of a SAM system, or an incoming new target ASM. To produce an updated schedule, a new biobjective mathematical model is formulated that maximizes the no‐leaker probability value for the TG and minimizes the total deviation from the initial schedule. With the problem shown to be NP‐hard, some special cases are presented that can be solved in polynomial time. We solve small size problems by the augmented ? ‐ constraint method and propose heuristic procedures to generate a set of nondominated solutions for larger problems. The results are presented for different size problems and the total effectiveness of the model is evaluated. 相似文献
742.
一种新的激光探潜方法 总被引:6,自引:2,他引:4
提出了一种不同于现有激光探潜原理的新方法,该方法利用潜艇尾流中气泡的光散射特性来探测和跟踪潜艇.对该方法的原理进行了简单的介绍,还对所涉及到的几个关键问题进行了初步的探讨和研究. 相似文献
743.
ABSTRACTThis article analyses findings from an original survey of 187 private military contractors on their incentives for working in the industry. Perceptions of contractors as “greedy, ruthless, and unscrupulous mercenaries” shape both public and military opinions of outsourcing and may impact U.S. military effectiveness, civil–military relations, and contractor identity. We find that contractors are motivated by a range of factors and that their financial experiences are not clearly more positive than that of state military troops. We recommend broad education of military and defense officials and the public in the U.S. and other relevant nations, regarding the true incentives of modern-day, Western contractors, in an effort to dispel misperceptions, increase effective utilisation of contractors, and beneficially shape PMC-military coordination. DoD may consider integrating such training into its current efforts to improve outsourcing, including its Joint OCS Planning and Execution Course, pre-deployment fora, and curricula of advanced military studies schools. 相似文献
744.
针对现有空战态势评估方法表现形式不够直观、模型简单的问题,提出一种将威力场与遗传神经网络相结合的态势评估方法,并将其应用于信息支援条件下的协同空战态势评估.分别从攻击能力、探测能力、电子干扰能力、生存能力、通信能力、告警能力、协同能力以及决策能力等方面构建威力势模型.利用遗传算法优化BP神经网络,并将其应用于编队作战能力评估.最后利用具体算例进行仿真验证,结果表明该方法是正确可行的.相比于传统态势评估方法,该方法在信息支援条件下的超视距协同空战态势评估中具有全面性、直观性、准确性等优势. 相似文献
745.
针对当前武器优化分配算法缺少通用性,难以兼顾效率和时间的问题,提出了一种通用型舰载防空硬武器火力优化算法。该算法首先提取各舰载武器能够攻击的目标集合,然后对各武器的目标集合逐一进行时间分配,并计算对目标的毁伤概率,最终完成所有武器的分配。计算表明,该算法具有很好的通用性和实时性,可适用于较大规模舰载防空硬武器的火力优化分配问题。 相似文献
746.
Corine M. Laan Ana Isabel Barros Richard J. Boucherie Herman Monsuur Judith Timmer 《海军后勤学研究》2019,66(2):174-190
In this paper, we introduce partially observable agent‐intruder games (POAIGs). These games model dynamic search games on graphs between security forces (an agent) and an intruder given possible (border) entry points and high value assets that require protection. The agent faces situations with dynamically changing, partially observable information about the state of the intruder and vice versa. The agent may place sensors at selected locations, while the intruder may recruit partners to observe the agent's movement. We formulate the problem as a two‐person zero‐sum game, and develop efficient algorithms to compute each player's optimal strategy. The solution to the game will help the agent choose sensor locations and design patrol routes that can handle imperfect information. First, we prove the existence of ?‐optimal strategies for POAIGs with an infinite time horizon. Second, we introduce a Bayesian approximation algorithm to identify these ?‐optimal strategies using belief functions that incorporate the imperfect information that becomes available during the game. For the solutions of large POAIGs with a finite time horizon, we use a solution method common to extensive form games, namely, the sequence form representation. To illustrate the POAIGs, we present several examples and numerical results. 相似文献
747.
748.
面向第四代战斗机的超视距空战 总被引:1,自引:0,他引:1
面对第四代战斗机的列装服役,其先进的技战术性能使得未来空战中超视距空战这种模式越来越占据主导地位,超视距空战具有其特殊的战术特点和影响其空战效果的因素,尤其是机载雷达和空空导弹的性能差异对超视距空战影响很大,因此要充分掌握战斗机的主要性能,做到取长补短.但是,空战中情况瞬息万变,任何时候也离不开飞行员和指挥员的灵活处置.只有在战斗机性能的不断提升的基础上,研究出相应的超视距空战战术,才能在未来高技术空战中真正具备打赢能力. 相似文献
749.
介绍了在无人机飞行试验中应用MEMS微惯性测量组合来解算飞行姿态、速度位置等参数的某个实例.试验结果表明,由此系统所得到的数据及曲线能够很好地描述实际飞行过程.试验数据为进一步地相关分析提供了有利的依据. 相似文献
750.