机动目标跟踪的模式集自适应IMM算法的设计和比较

变结构多模型状态估计器方法适用于雷达跟踪空中机动目标。本文研究和设计了两种自适应时变模式集交互多模型(IMM)跟踪滤波器;切换网格(SG)IMM和自适应网格(AG)IMM算法。针对不同的飞行想定,通过Monte Carlo仿真方法对这些算法及相应的固定网格(FG)IMM滤波器的性能进行了评估和比较。仿真显示,对特定的机动目标跟踪问题,SGIMM和AGIMM跟踪滤波器在性能和计算量等方面要比固定结构多模型算法(FGIMM滤波器)有明显地提高。     

模型参数自适应的交互多模强跟踪算法

基于强跟踪滤波器对突变状态的良好跟踪能力,设计了一种自适应交互多模算法.在交互多模算法框架内,计算"当前"统计模型的概率和目标机动强度信息(由残差统计距离来表征),自适应地调整"当前"统计模型的加速度等参数,提高了"当前"统计模型的自适应性和滤波器的鲁棒性,增强了系统对目标突发强机动的跟踪能力.仿真结果验证了该算法的有效性.     

一种修正的自适应网格交互多模型算法

将径向速度引入到自适应网格交互多模型算法中,并针对自适应网格算法在跟踪过程中网格中心不稳定的问题增添模型集改变阈值,提出了一种修正的自适应网格交互多模型算法。同时对一些关键参数作了深入研究。仿真表明,提出的修正算法提高了算法稳定性,增强了模型滤波器与真实运动模式的匹配程度,减小了跟踪的速度误差和距离误差,很好地改善了跟踪性能,并具有全面自适应的跟踪能力。     

防发散无迹卡尔曼滤波自适应网格交互式多模型算法

针对非线性观测条件下的机动目标跟踪问题,基于机动目标的协同转弯模型,采用防发散无迹卡尔曼滤波方法和自适应网格的模型集自适应策略,研究了一种变结构交互式多模型算法。对二维机动目标跟踪的仿真结果表明,该算法与相应的固定结构交互式多模型算法相比,可以解决固定结构多模型算法存在的问题,有效提高多模型算法的精度和费效比,缩短计算时间,且适合工程应用。     

基于UKF的自适应网格交互式多模型算法

针对非线性观测条件下的机动目标跟踪问题,基于机动目标的协同转弯（CT）模型,采用无迹卡尔曼滤波（UKF）方法和自适应网格（AG）的模型集自适应策略,研究了一种变结构交互式多模型算法,即：基于UKF的自适应网格交互式多模型（UKF-AGIMM）算法。对二维机动目标跟踪的仿真结果表明,本算法与相应的固定结构交互式多模型算法相比,可以解决固定结构多模型算法存在的问题,有效提高多模型算法的精度和费效比,缩短计算时间,且适合工程应用     

基于参数自适应CS模型的机动目标跟踪算法

为提高对机动目标的跟踪精度,提出一种基于参数自适应当前统计(CS)模型的跟踪算法。即利用加速度增量与位移的关系,自适应调整加速度方差,根据量测残差的统计距离判别目标机动特性,并调整模型的机动频率和滤波器增益系数,提高算法模型与目标机动模式的匹配程度。仿真结果表明,基于参数自适应CS模型跟踪算法能够较好地改善对强机动目标的跟踪性能。     

基于模型概率估计的两层交互多模型算法

在机动目标跟踪问题的研究中,针对转弯机动目标跟踪精度差的问题,设计了一种利用模型概率对模型集合进行实时计算的两层交互多模型算法。该算法由第一层目标转弯速率的粗估计和第二层目标状态向量的精估计构成,它利用第一层模型计算出的目标运动估计转弯速率,构建与当前目标运动状态匹配程度较高的第二层转弯模型集合,并将该转弯模型集合运用于状态估计中。仿真结果证明了该算法在针对转弯机动目标时仍有较好的跟踪精度。     

基于模糊推理的机动目标自适应多模型跟踪算法

针对当前空中来袭目标的主要特点,运用模糊理论和多模型理论探索空中机动目标跟踪问题,并设计了一种模糊自适应多模型(FAMM)目标跟踪算法,该算法采用五个基本模型,以加速度估值作为模糊推理系统的输入,经模糊推理融合得到系统状态和方差的估计值以及下一时刻的滤波模型(最多三个).经Monte Carlo仿真研究,与IMM算法相比较,该算法不仅在目标弱机动或不机动条件下,而且在复杂机动时能更稳定、精确地跟踪目标,较好地满足了海上对空防御作战中跟踪机动目标的需求.     

一种基于当前统计模型的模糊交互多模型算法

研究了模糊交互多模型算法(FIMM)和基于当前统计模型(CS)的自适应滤波算法,提出了一种基于当前统计模型的模糊交互多模型算法(CSFIMM)。该算法克服了模糊交互多模型算法精度较低和当前统计模型自适应滤波器方差调整有限的缺点。通过仿真,对所提出的算法和交互多模型(IMM)算法以及FIMM算法在估计精度和计算量两个方面进行了比较。     

基于模型概率的自适应交互式多模型算法

传统的交互式多模型算法中过程噪声协方差矩阵固定，不能很好地适应实际目标不同程度的机动。采用匀速和转弯运动模型集合，提出了一种基于模型后验概率的自适应交互式多模型算法。通过后验概率来自适应调整各模型中的系统过程噪声协方差矩阵，进而提高模型同系统运动模式的匹配程度；结合防空作战机动目标跟踪要求，通过典型目标机动仿真，同标准交互式多模型算法进行比较，验证了该算法的合理性和有效性。     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

Tacit support for terrorism: The rapprochement between the USSR and Palestinian guerrilla organizations following the 1967 war

This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.     

A1 Qaeda and the radical Islamic challenge to western strategy

The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.     

Helping hands: external support for the KNU insurgency in Burma

This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.     

基于GTST-DMLD-ESD的装备RMS建模仿真

装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.     

Cyber sheiks and grassroots jihadis: the war in Syria and the devolution of the Bosnian Salafi communities

ABSTRACT

What was the scope of the Bosnian jihadi participation in the war in Syria? Did the Bosnian volunteers tend to join one particular faction? Why did the Bosnian youngsters decide to join the holy war in the Levant? Was this an organized and hierarchical process or was this a grassroots movement? Last, were all the Salafis in Bosnia supportive of this dynamic or did this process cause internal frictions? These are some of the questions that this research will try to answer.     

The UK,interrogation and Iraq, 2003–2008

The UK’s interrogation operations during the conflict in Iraq (2003–2008) are often portrayed by the media as involving significant amounts of mistreatment. This article demonstrates that these practices are not necessarily representative of the UK’s interrogation operations across this conflict. In doing so it contributes to the limited literature on the practice of interrogation and on the UK’s combat operations in Iraq. The UK’s interrogation capability, and therefore its intelligence-gathering capability, is shown to have rested primarily with the military’s Joint Forward Interrogation Team (JFIT). The JFIT suffered from limitations to the number, training and experience of its interrogators and interpreters. It is argued that maintaining a permanent, higher level of preparedness for interrogation by the British armed forces is desirable.     

Remembering and forgetting Mirambo: Histories of war in modern Africa

ABSTRACT

While the study of organised violence is considered essential to understanding the history of the West, and accordingly imbued with various layers of meaning and remembrance, war is widely regarded as inimical to the modern nation in Africa and stable development more broadly. Using examples drawn from primarily from East Africa, this paper considers the ways in which warfare in the deeper (‘precolonial’) past has been framed and envisioned in recent decades, in particular by governments whose own roots lie in revolutionary armed struggle and who began life as guerrilla movements. While in some cases particular elements of the deeper past were indeed mobilised in pursuit of contemporary political goals, in many other scenarios histories of precolonial violence were beheld as problematic and unworthy of remembrance. This paper highlights the paradox and ambiguity which has attended the memory of key aspects of Africa’s deeper past.