一种结合弹道规律的模糊交互式多模型算法

针对交互式多模型算法中转移概率矩阵与实际运动不匹配而影响跟踪精度的问题,通过分析某型导弹的典型弹道,将弹道规律融合到模型概率转移矩阵中,然后将转移概率模糊化处理,提出了一种基于弹道规律的模糊交互式多模型算法,然后以导弹蛇形运动转至比例导引的机动过程为例进行了仿真验证,比较了典型交互式多模型算法和模糊交互式多模型算法的跟踪性能。仿真结果表明:该算法可显著提高导弹机动段的跟踪精度。     

基于改进IMM-UKF的弹道导弹再入段跟踪数据滤波?

针对弹道系数未知的弹道导弹再入段跟踪雷达测量数据滤波这类非线性强的滤波问题,提出可变多模型无迹卡尔曼滤波算法。利用无迹卡尔曼滤波逼近精度高,计算量小,适应于任意非线性模型的特点,将其作为多模型的基本滤波器;滤波算法根据各模型正确描述目标状态的概率,动态地改变多模型数量和模型参数。上述方法的综合运用,提高对目标状态估计精度,降低了计算的复杂度,仿真实验验证了方法的有效性。     

瞄准式战斗部瞄准策略研究

对不同的瞄准点,瞄准式战斗部对目标毁伤效果不同,为此提出了适用于瞄准式战斗部的瞄准策略,保证了对目标较高的毁伤概率和较好的毁伤效果,解决了起爆之前战斗部的定位问题。     

非相参三点源有源诱偏下ARM弹着点研究

非相参多点源诱偏技术是对抗反辐射导弹(ARM)的有效手段。以ARM目标分辨的二分组理论和双点源诱偏的仿真结果为依据,对等功率三点源诱偏的2种经典布局的ARM落点整体分布进行预测。通过对ARM落点和系统被击中概率曲线的分析及拟合处理,验证了预测的正确性及系统被击中概率与占地面积的相关性,为通信辐射源抗ARM的布设提供一定的参考。     

战术导弹对机场跑道多波次打击时的瞄准点选择方法

为了解决使用战术导弹对机场跑道实施多波次打击时的瞄准点选择问题,在考虑具有先前毁伤效果的累积效应基础上,按照优先打击最小起降窗口、使最小维修窗口中维修工作量最大的思路,设计了一种瞄准点选择方法,可为相应的导弹作战运用提供参考。所附算例说明了文中方法的可行性。     

They protect us,but are they using protection? The potential impact of HIV on the South African Police Service

The drivers of HIV/AIDS in the South African Police Service (SAPS) and impact of the disease on this workforce are neglected areas of research. Existing evidence suggests that while the occupational risk for contracting HIV is low, there are factors associated with the profession that, if left unmanaged, place police officers at risk of contracting HIV. This study's two aims are to identify the potential pathways of HIV infection within policing services and determine the probable impact of HIV/AIDS on SAPS. Through a systematic literature review on HIV/AIDS within police services, and by analysing selected SAPS human resource data, the causal pathways and impact of HIV/AIDS on police services are explored. The study finds that police officers (particularly male officers) are likely to be highly susceptible to HIV infection as a result of risky sexual behaviours born out of occupational characteristics such as high levels of stress, difficult working conditions, living away from home and interactions with sex workers. The problem is exacerbated by the ‘macho’ culture that often prevails among police officers. HIV/AIDS interventions within SAPS must focus on sustained behaviour change. Further, HIV programmes must equip officers with the knowledge and awareness to avoid engaging in high-risk sexual practices that may compromise their health and the effectiveness of the policing service.     

Why a small probability of terror generates a large macroeconomic impact

The basic narrative of bargaining theory predicts that, all else equal, anarchy favors concessions to challengers who demonstrate the will and ability to escalate against defenders. For this reason, post-9/11 political science research explained terrorism as rational strategic behavior for non-state challengers to induce government compliance given their constraints. Over the past decade, however, empirical research has consistently found that neither escalating to terrorism nor with terrorism helps non-state actors to achieve their demands. In fact, escalating to terrorism or with terrorism increases the odds that target countries will dig in their political heels, depriving the non-state challengers of their given preferences. These empirical findings across disciplines, methodologies, as well as salient global events raise important research questions, with implications for counterterrorism strategy.     

ADVANCED US CONVENTIONAL WEAPONS AND NUCLEAR DISARMAMENT

The Obama administration has made a great effort to increase the role of advanced conventional weaponry in US national security thinking and practice, in part to help reinvigorate the global nuclear disarmament agenda by reducing the role played by nuclear weapons in the US defense posture. However, such a strategy is fundamentally flawed because increases in US conventional superiority will exacerbate US relative strength vis-à-vis other powers, and therefore make the prospect of a nuclear weapon-free world seem less attractive to Washington's current and potential nuclear rivals. Consequently, it is highly likely that the impact of efforts to increase US advanced conventional superiority through ballistic missile defense and a conventional “prompt global strike” program will ensure that the Obama administration is adopting a pathway to nuclear abolition on which it is the sole traveler for the foreseeable future.     

UNDER THE RADAR?

Missile Contagion: Cruise Missile Proliferation and the Threat to International Security, by Dennis M. Gormley. Praeger Security International, 2008. 272 pages, $54.95.     

地球外部空间扰动引力并行计算

针对传统的司托克斯积分方法计算量大、模型复杂的缺点,通过将地球球面以适当的经纬度差进行划分及合理简化,实现了司托克斯积分法计算外部空间扰动引力的积分方程的离散化,建立了地球扰动引力的快速计算模型,并在快速计算模型的基础上采用并行计算技术,实现扰动引力的实时计算。仿真结果表明,提出的快速并行计算模型能较好地实现地球扰动引力的快速、高精度计算。