有源三阶低通滤波器

通常使用有源滤波器用来弥补简单的无源LC滤波器的缺陷。下面所给出的有源滤波器,是采用最少的元件,使用一种电源,就可提供具有各种希望特性的低通滤波器(如巴特伍兹特性、古比雪夫特性、贝塞尔特性等)。图(1)所示的电路是本文所要设计的有源滤波的一种形式,它的特点之一是采用二个晶体管BG_1和BG_2构成简单的放大器,可以代替一个运算放大器,使线路简单,成本     

一种雷达测量的目标导弹角偏差滤波方法研究

制导雷达同时测量目标和导弹的角偏差;通过对角偏差源的分析和角偏差频域的分析,确定采用不同带宽的巴特沃斯低通滤波器来消除其中的噪声.由于导弹和目标飞行动态特性的差异,及雷达伺服特性影响,研究得出应在导弹飞行的不同时间段选择不同带宽的滤波器以达到最佳的滤波效果.     

自适应交互式多模型滤波在被动制导中的应用

首先给出了一种更加简单的关于BOM问题的变增益函数的推导,新的增益形式比原先的形式更具有数字稳定性.然后考虑当模型具有不确定性时的被动制导仿真.当模型具有参数不确定时,一般的单模型滤波器已经不能满足制导的性能要求.采用交互式多模型算法,与修正增益扩展卡尔曼滤波器结合,并使用能实时估计量测噪声的Sage-Husa估值器,设计出一种新型自适应交互式多模型修正增益扩展卡尔曼滤波,将其应用到被动制导中,仿真结果表明该方法的优越性和实用性.     

基于自校正卡尔曼滤波器的信息融合算法

设计了一种新的基于ARMA模型自校正卡尔曼滤波器及其信息融合的方法,从而避免了经典卡尔曼滤波器需要精确知道系统的模型参数和噪声统计特性的缺点.仿真结果表明,在未知部分模型参数和噪声统计特性的情况下,自校正卡尔曼滤波器的滤波性能非常接近稳态最优卡尔曼滤波器;基于自校正卡尔曼滤波器的信息融合滤波性能接近基于稳态最优卡尔曼滤波器的信息融合滤波性能.     

一种色噪声下的自适应Kalman跟踪滤波器

有色噪声干扰情况下非线性系统的状态估计是许多实际工程需要解决的问题.该文章针对传统Kalman滤波器噪声统计特性未知时,受色噪声的影响精度严重降低,甚至出现发散等现象,设计了一种基于神经模糊网络的自适应的Kalman滤波跟踪器.该滤波器通过利用神经模糊网络作为误差估计器,估计出Kalman滤波器的估计误差,从而对Kal...     

串联型有源电力滤波器的控制策略

通过所给出的串联型有源电力滤波器系统结构 ,分析了其补偿电压型负载的工作原理。在此基础上探讨了串联型有源电力滤波器的关键技术之一———获得参考电压的控制策略 ,包括检测电源电流和检测负载电压两种控制策略 ,并设计了相应的控制电路。最后 ,通过实验研究了串联型有源电力滤波器采用这两种不同控制策略时对电压型负载的谐波补偿效果     

MIC 多节滤波器的制作

本文记述了五、七节耦合微带带通滤波器的设计、制作和实验结果。结果证明,随着节数的增多通带衰减几乎没有增加。结果还证明,基片介电常数和微带长度的精度在计算带通位移时有重要影响。最后,还给出了一个计算此效应的简单公式。     

矩阵变换器输入滤波器设计与研究

针对当前输入滤波器设计方法存在通用性低的缺点,通过对影响输入电流和输入电压谐波的因素及其谐波特性的分析,提出了一种以满足滤波性能和成本及体积最小为目标的设计方法,并针对特定工况下的滤波器参数进行了设计,以此给出了滤波器的设计步骤。仿真与试验结果表明:采用所提滤波器设计方法的矩阵变换器,其网侧电流和电容电压均能满足国家电网电能质量的要求,证明了所提方法的可行性。     

序统计滤波器的一些特性

本文分析了序统计滤波器的特性,并提出了它的几个统计特性。给出了输出信号的解析表达。并着重分析了它的联合分布,从而对输出信号的独立性进行了一定的描述。这为滤波器的设计提供了理论依据     

RTDX与Matlab实现基于DSP的FIR滤波器设计

介绍了一种RTDX与Matlab结合设计基于DSP的FIR数字滤波器的方法.在VB中调用Matlab进行指定特性FIR数字滤波器设计,获得各阶权系数,然后调用RTDX,实时地向目标硬件传递该系数,从而实现了基于DSP的FIR数字滤波器精确设计,提高了DSP算法软件的设计效率.并对TI的RTDX技术及使用方法作了相关介绍.     

Putin – the masked nemesis of the strategy of ambiguity

Recent events demonstrate the complex and adaptive approach employed by Russia to reassert influence in Europe. The changing face of Russia’s strategy commenced in 2007 when it launched a crippling cyber-attack against Estonia. This was followed by a large Russian conventional attack against Georgia in 2008, occupying two large areas of the nation. 2014 witnessed the Russian annexation of Crimea where in just a week, Russia seized control of Crimea “without firing a shot.” The annexation of Crimea was rapidly followed by a Russian inspired and led subversive war in eastern Ukraine. The common thread among these diverse Russian operations is its use of ambiguity to confound and confuse decision makers in the West.     

India's counter-insurgency experience: the ‘trust and nurture’ strategy

The Indian Army, a force trained primarily for conventional warfare, has been engaged in internal counter-insurgency operations since the 1950s. Despite such a long innings on a counter-insurgency mode, little attention has been accorded within military circles to doctrinal innovation for waging sub-conventional warfare in India's democratic political context. At best, the Army continues to view counter-insurgency duty as secondary to its primary duty of defending India from external conventional threats. By conceptualizing a counter-insurgency strategy of ‘trust and nurture’, this article aims to fill this critical doctrinal gap in India's military policy. The author argues that a counter-insurgency strategy of ‘trust and nurture’ based on democratic political culture, measured military methods, special counter-insurgency forces, local social and cultural awareness and an integrative nation-building approach will result in positive handling of India's internal security problems. The author utilizes India's counter-insurgency experiences in Assam, Mizoram, Nagaland, Punjab, and Operation ‘Sadhbhavana’ in Jammu and Kashmir as illustrative empirical indicants in order to validate the ‘trust and nurture’ strategy.     

An Unlikely Alliance: Portuguese and South African Airpower in Angola, 1968–1974

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.     

国内外结构钢焊条研究的现状与发展

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。     

A Sign of Victory?: ‘Scottish Swords’ and Other Weapons in the Possession of the ‘Auld Innemie’

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.     

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.     

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).     

Cyberpower in Strategic Affairs: Neither Unthinkable nor Blessed

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.     

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.