潜艇占位可行性分析

目标、潜艇及其鱼雷武器系统和水文环境是潜艇鱼雷攻击的基本条件。占领射击阵位是攻击中所要完成的基本任务之一。从分析鱼雷射击可行域、潜艇机动可行域入手给出了在一定攻击条件下的潜艇占位可行域。     

点型火灾报警探测器保护范围对布置的影响

分析了点型火灾报警探测器＂保护半径＂与＂保护面积＂的内在关系,得出了以保护半径为主,保护面积及修正系数为辅新型计算方法,使其在不规则平面更有可操作性,能充分发挥探测器效能,给设置留下了宽裕的选择范围,使设置更趋合理;在安全性不受影响下,探测器用量最大可节省12%。     

布站形式对TDOA无源区域定位系统定位精度的影响

基于TDOA的陆基多基站定位系统的布站形式对定位系统的定位精度具有较大影响.给出了基于TDOA的陆基无源定位系统的定位算法和定位精度模型,对各种布站形状对定位精度的影响作了简单的仿真和分析,并主要分析了倒三角形式下各种要素对定位精度的影响.对陆基无源区域定位系统的布站形式提出了一些建议.     

多UAV协同区域覆盖侦察方法

针对多UAV对未知区域的协同覆盖侦察问题,提出了将STC算法与在线局部调整策略相结合的区域覆盖侦察方法.通过建立无重叠覆盖区域的闭合路径,最小化了重复侦察区域,缩短了任务执行时间;通过在线局部调整保证了只要有一架UAV不出现故障,侦察任务就可以正常进行.仿真结果表明,该方法能够有效解决多UAV协同区域覆盖侦察问题,方法...     

基于模糊数学对区域太阳能利用潜力的综合评判

应用基于模糊数学的综合评判方法主要对北京、长春、济南、拉萨、昆明、银川、乌鲁木齐和重庆八个城市地区太阳能利用潜力进行了评判和分析,综合考虑了日照百分率、年总云量等因素对太阳能利用的影响,建立了太阳能地区适用性综合评价指标体系,评价的权重集、判断矩阵、隶属度函数,并以八城市为例给出具体步骤和结果,比较科学地对我国太阳能利用潜力进行了科学评判,对我国的太阳能地区利用具有借鉴意义.     

Combining standardized time series area and Cramér–von Mises variance estimators

We propose three related estimators for the variance parameter arising from a steady‐state simulation process. All are based on combinations of standardized‐time‐series area and Cramér–von Mises (CvM) estimators. The first is a straightforward linear combination of the area and CvM estimators; the second resembles a Durbin–Watson statistic; and the third is related to a jackknifed version of the first. The main derivations yield analytical expressions for the bias and variance of the new estimators. These results show that the new estimators often perform better than the pure area, pure CvM, and benchmark nonoverlapping and overlapping batch means estimators, especially in terms of variance and mean squared error. We also give exact and Monte Carlo examples illustrating our findings.© 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

故障字典法的区域性故障定位

本文针对故障字典法在电路故障诊断中存在低效率的问题,提出了区域性故障定位的方法,即将所考虑的故障划分成不同的区域,通过对故障所在的区域进行定位,提高故障检测效率。并举例说明了该方法的实际应用。     

被掩护地面固定目标不受空中打击分析

重点分析了被掩护地面固定目标不受空中打击的相关因素,并定量地分析了敌空袭兵器攻击地面被掩护目标时所需的数量,从而为地面防空建立最佳的防空部署提供依据。因为防空兵群对空袭兵器的射击次数与防空兵群的杀伤区面积成线性关系,所以在探讨如何部署防空兵力时,以防空兵群的杀伤区面积为准则来建立线性规划模型。     

Epidemics,national security,and US immigration policy

What are relationships between epidemics, national security, and US immigration policy? This question is important because it sheds light on transnational or nontraditional security areas, American immigration policy, and a pressing issue for US leaders who have recently faced epidemics such as the West Africa Ebola outbreak that began in 2013. This article answers it and lays ground in the area by reviewing epidemics in world history, using International Relations and Security Studies works to specify dangers of contagions for states, and identifying three general immigration measures that American leaders have utilized from the seventeenth century to the present day to protect against contagions, which are (1) policies restricting entrance of foreigners thought to carry specified diseases, (2) the isolation or quarantining of immigrants with contagious disease, and (3) delegating the President with authority to stop immigration in the event of an epidemic abroad. This study has implications for research and contemporary US immigration policy.     

火箭出口面积对RBCC发动机引射模态影响规律分析

火箭基组合循环发动机引射模态飞行状态复杂,为了提高发动机的整体性能,研究了火箭出口面积对发动机引射模态的影响规律。通过数值模拟研究,引射流量在低飞行马赫数条件下,主要受引射性能影响,火箭出口面积越大,引射性能越好。然而,随着飞行马赫数的提升,引射空气的动能提升,隔离段内出现壅塞情况,引射流量主要受限于隔离段几何尺寸,与火箭出口面积无关。在亚声速工况下,火箭出口面积越小,发动机比冲越低,且出口无量纲面积为3.15时,火箭羽流膨胀撞壁,会引起性能骤减,需要予以避免;在超声速工况下,选择面积较小的火箭出口面积,燃烧室内压越高,发动机性能提升越明显。