战车火控系统射击命中三要素函数误差分析

火控系统射击(函数)误差可分解为射弹散布函数误差和火控射击准备函数误差。而射击准备函数则是命中三要素函数即瞄准函数、解算函数和控制函数的合成函数。命中三要素的提出,为火控系统射击误差(精度)的分析提供了新的途径。它们均是命中目标的关键要素,又各具特色,为火控系统射击精度乃至系统反应速度的提高,指出了应该努力的方向。针对此进行了具体的分析。     

神经网络的坦克目标威胁评估

在未来高技术局部战争条件下,坦克不得不面临一个动态复杂的战场环境,这就要求坦克能根据战场环境实时地进行目标威胁评估及自主射击。以坦克的自主作战为背景,提出了一种基于神经网络的目标威胁评估方法。首先提出了包含来袭目标性质、指战员指令、保卫目标的重要度、我方武器性能值等一套威胁评估指标体系;然后采用神经网络方法进行威胁评估。神经网络方法的优势主要体现在:①考虑了诸因素的相互关联;②充分考虑了战术信息;③权系数对具体环境的适应性;④方法的通用性。实例结果表明,神经网络方法科学合理,为坦克目标威胁的评估提供了新思路。神经网络方法具有普遍意义,能推广应用于其它武器平台的目标威胁评估。     

分布式放大前传中继辅助多用户对等通信中的鲁棒波束成形

针对分布式放大前传中继辅助多用户对等通信系统研究了存在非理想信道状态信息(CSI)时的分布式中继网络(DRN)鲁棒波束成形设计问题。采用统计CSI误差模型,考虑了两种鲁棒优化问题:一是从公平性的角度出发在DRN总发送功率约束下实现多个目的节点间的信干噪比(SINR)平衡;另一是从有效性的角度出发在保证各个目的节点服务质量需求(SINR大于预设门限)约束下最小化DRN总发送功率。对问题的分析和建模表明,在多用户情况下,这两个问题都是难以求解的优化问题。通过引入半定松弛(SDR)思想,将上述两种优化问题转化为可利用内点法有效求解的半定规划(SDP)问题。最后通过仿真验证了所提设计的鲁棒性能。     

‘Today we shall drink blood’: internal unrest in Nigeria

Despite some tentative internal peace agreements, Nigeria continues to face violence from multiple groups. This violence feeds upon itself, with segments of the population being mobilized both for self defense and for pressing their ideological and practical goals. These multiple sources of violence, which the Nigerian government appears unable to control to any significant degree, have a long term corrosive effect on the country's internal stability. There are few reasons to be sanguine as to any rapid changes to the level of overall violence or the relative number of armed groups, although their specific identities may shift. Nigeria represents a good case study of a country in which relatively low but persistent violence by a multiplicity of groups can have major impacts on internal security.     

Controlled warfare: how directed-energy weapons will enable the US Military to fight effectively in an urban environment while minimizing collateral damage

US military operations are increasingly conducted within urban environments and with these operations come the risk of increasing the number of civilian casualties and infrastructure damage. The use of non-lethal weaponry, such as directed-energy weapons, is one method for minimizing collateral damage. This method enables US military forces to effectively fight within urban environments through force escalation capabilities. Using a series of historical examples and future scenarios for urban warfare, this article highlights deficiencies affecting military capabilities in military urban operations, addresses the consequences of collateral damage, assesses the effectiveness of directed-energy weapons in military urban operations and encourages further funding, research and integration of non-lethal weaponry, such as directed-energy weapons, within the US military.     

基于TCP Veno算法的异构网络边界代理改进机制研究

针对在异构网络环境下无线网络的特点使TCP性能下降的问题,借鉴TCP Veno算法原理,提出基于网络状况评估的拥塞控制的性能增强代理改进工作机制,动态评估当前网络的状况,调整预应答发送窗口的阈值,提高性能增强代理在较大差异网络下的传输控制效能．基于NS-2的网络仿真测试对算法进行了验证,结果显示改进后的工作机制在丢包率较大的异构网络中性能有明显提升．     

基于AFSA的自抗扰控制器参数整定

自抗扰控制器（ADRC）的参数众多,通常依赖于人工试凑优化,控制系统的性能好坏过分取决于设计人员的经验且效率不高。针对ADRC的参数选取问题,首次利用鱼群算法（AFSA）全局寻优能力强,鲁棒性好的特点,结合已有的参数整定经验,提出了一套基于AFSA的ADRC参数整定规则,并进行了数字仿真。仿真结果表明,经由基于AFSA参数整定规则优化过后的ADRC具有良好的动静态特性,提高了设计效率,验证了该方法的可行性和有效性。     

基于辅助制导的无人飞行器有向航迹网络图设计

基于辅助制导的无人飞行器多航迹规划是现今航迹规划的主流研究方向之一。飞行器规划空间广,规划过程耗时长,如何提高航迹规划的速度是一个急待解决的问题。因此,提出了一种在预处理过程中生成的、满足战场环境和基于辅助制导无人飞行器飞行特性的有向航迹网络图。该网络图适用于基于辅助制导的无人飞行器多航迹快速规划,使用数据库存储和管理,具有整体数据结构化、易扩充、占用内存资源小、可大大缩短规划时间等优点。     

MODELLING THE RELATIONSHIP BETWEEN DEFENSE SPENDING AND ECONOMIC GROWTH FOR THE FIJI ISLANDS

The goal of this paper is to examine the nexus between GDP and military expenditure. We model this relationship within a multivariate framework by including exports in the model. We use the recently developed bounds testing approach to cointegration and find that there is a long run relationship among the variables when GDP is the endogenous variable. Normalizing on GDP and using four different estimators, we find that in the long run both military expenditure and exports have a positive impact on GDP. Finally, using the Granger causality test, we find that there is evidence for military expenditure Granger causing exports and exports Granger causing GDP, implying that military expenditure indirectly Granger causes GDP in the short run. In the long run, we find that both military expenditure and exports Granger cause GDP for Fiji. Our findings are consistent with the Keynesian school of thought, leading us to derive some policy implications.     

Prices and quantities in the arms trade*

There are two main sources of information about the Arms Trade, SIPRI and ACDA. These two sources give very different pictures of the evolution of the market, primarily because their measures are designed to capture conceptually different features. Although they are both expressed in constant dollars, the SIPRI series is designed to be a volume index of physical transfers, the ACDA series a constant price value index. Thus in principle, the ratio of the ACDA to SIPRI series should provide an implicit price index of arms; though in practice there are many measurement problems. In this paper, we discuss the basis of these indices and show that the ratio, the implicit price, not only looks plausible in the light of the evolution of the market, but has a significant negative effect on the demand for arms imports in an econometric equation.