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以同步发电机为分析对象,利用粗糙集可有效地处理和分析不精确的信息和知识的优点,从历史信息和决策中进行了特征量选取以及属性约简.对于无法处理的属性约简,采用条件限制得到能够有效反映属性的重要程度特征量,并以此计算特征量权重系数,消除主观因素的影响.在此基础上,针对励磁绕组绝缘故障,选择与设备健康状态直接相关特征作为判断对象,与同机组历史数据进行相似度分析,计算得到了其故障因子.设计出快速判断相关状态的算法,给出了判定准则并进行了编程实现.实验验证表明:该诊断算法能够对设备故障进行有效判定. 相似文献
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采用门限关联度理论进行变速箱状态检测,并构建了以虚拟仪器为核心的变速箱状态采集系统,建立了表征变速箱状态的特征参量和正常故障判定准则,采用LabVIEW开发了检测与故障判定软件系统。 相似文献
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应用分层多模自适应滤波算法对控制系统的故障进行诊断时,只能识别出故障的类型,如识别出是传感器还是执行器发生故障,并不能判定出故障的大小.提出一种改进分层多模自适应滤波算法,应用此算法可使分层多模自适应滤波算法不仅可以检测出控制系统的故障类型,而且能够确定发生故障的执行器局部故障程度.将此算法应用于某无人机控制系统的故障诊断,仿真结果验证了该方法的有效性. 相似文献
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该文提出了一种实用的捷联惯测系统总体性能测试和故障分离方法。这种方法不仅能够快速确定捷联惯测系统总体性能的好坏,而且一旦判定系统存在故障还能迅速进行故障分离,进一步确定故障部位。 相似文献
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针对某型导弹飞行掉弹故障,依据导弹武器系统组成结构,采用FTA方法,研究了故障模式与故障部位,并通过试验对故障定位进行了验证;分析了故障产生的原因与机理,提出了避免该类故障的相应措施. 相似文献
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如何判定仿真组件之间是否可组合是组合仿真中的关键问题之一.建立了组合判定问题的参考模型,基于Hoare逻辑给出仿真模型语义的描述方法,并以此为基础通过构造模型语义之间的组合匹配规则,从组合相容性及可替换性两个方面刻画模型的可组合性质.形成语义层次的组合判定方法;对组合相容性与可替换性质之间的关系进行了分析. 相似文献
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针对柴油机失缸故障检测排除工作效率低的问题,利用瞬时转速分析方法实现柴油机失缸故障快速检测。通过坦克实车故障模拟试验,测量了柴油机气缸失火时的瞬时转速信号,采用非线性插值方法对瞬时转速序列进行整周期调整。利用小波包分解方法对瞬时转速信号提取了转速波动信号,分析提取了瞬时转速信号的复杂度和时域、频域特征,建立了基于支持向量机的故障诊断模型,实现了气缸失火故障诊断,并利用瞬时转速波动率作为判定参数,实现了故障定位。 相似文献
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The war that Portugal was obliged to fight in Africa began in 1961 and immediately stretched the resources of its armed forces. Nowhere was this thinness more apparent than in policing the vast territory of Angola. The east and southeast of Angola were particularly vulnerable, as the area was a vast, sparsely populated region characterised by enormous featureless plains or chanas covered in tall grass and broken by an extensive river system and mountainous forests. The only military solution to policing these immense spaces was aviation and specifically the helicopter that could carry troops into battle, protect them with a gunship and bring them home when the operation was concluded. The immediate problem for the Portuguese Air Force (Força Aérea Portuguesa or FAP) in Angola and elsewhere was a scarcity of helicopters. The solution was an alliance with South Africa, which had a strong inventory of Alouette IIIs, to help in policing the east. This move was likewise in the interest of South Africa, as its threat came from Zambia through south-eastern Angola. This article examines the strategic and tactical development of this unusual, cross-cultural alliance and the symbiotic relationship that resulted in destruction of the enemies of both in Angola. 相似文献
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本文主要介绍了国外焊条的现状和发展趋势,包括焊条的高韧性、高效率、低尘低毒和耐吸潮性能,为国内的焊条研究提供了参考依据。 相似文献
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《Arms and Armour》2013,10(2):122-143
Many late medieval documents, notably inventories of arms and armour, of Englishmen contain references to ‘Scottish swords’ and other weapons. What did the compilers of these documents mean when they described a weapon as ‘Scottish’? How did such weapons come to be in the possession of these men? This article will attempt to explain this phenomenon drawing on primary documentary sources and surviving material culture from Glasgow Museums’ collections and others, as well as artworks from the period. 相似文献
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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. 相似文献
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Lord Aikins Adusei 《African Security Review》2013,22(3):332-359
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). 相似文献
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《战略研究杂志》2012,35(5):689-711
Abstract This article explores the effect of connectivity on strategic affairs. It argues that the effect on war's character is potentially, although not yet shown in practice, considerably large. Its effect upon the distribution of power among states in the international system is small, contrary to the claims of ‘cyberwar’ alarmists. All told, however, its effect upon strategic affairs is complex. On the one hand, it represents a significant advance in the ‘complexification’ of state strategies, understood in the sense of the production of intended effects. On the other hand, strategists today – still predominantly concerned with the conflicts and confrontations of states and organised military power – are generally missing the power which non-traditional strategic actors, better adapted to the network flows of the information age, are beginning to deploy. These new forms of organization and coercion will challenge the status quo. 相似文献
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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. 相似文献
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Paul Rich 《Small Wars & Insurgencies》2013,24(1):39-56
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. 相似文献