基于程序切片的电路提取技术

从HDL设计描述中提取电路在VLSI设计验证、低功耗分析、测试生成等方面有广泛的应用需求。提出了一种采用程序切片技术实现的新的电路提取方法,并深入论述了基于程序切片技术从Verilog描述中进行电路提取的理论基础。该方法可以为每一个感兴趣的信号获取其"链接切片"。与以前的方法相比,该方法的优点是细粒度的、不受书写格式的限制,并且能处理更多Verilog的语法元素。该方法已经被集成到现有设计流程中,实验结果表明其方便、高效,有良好的通用性。     

基于类成员后向切片的面向对象程序回归测试

程序切片是一种重要的程序分析方法,类成员级粒度的切片技术目前仅仅有Tip提出的类层次切片技术.Tip提出的类层次切片技术其分析基础是Rossie-Friedman的类层次框架,但主要用于面向对象程序的优化,并不适用于回归测试.本文基于Rossie-Friedman的类层次框架提出类成员后向切片方法,并提出一个覆盖类的方法一级的回归测试策略.     

基于最少谓词思想的可达路径选择

对于结构测试中的不可达路径问题,仅仅使用传统的不可达路径排除方法存在很大的限制性,应用效果一般.积极选择可达路径的思想可有效减少不可达路径的产生.目前,基于最少谓词思想的路径生成方法得到广泛的认可.了解可达路径选择思想后,主要介绍一种基于数据流信息的,具体应用基本程序切片技术来生成可达路径的方法,该方法可生成几乎有最少谓词的路径,有较好效果.     

采用非对角1-D切片的码片速率盲估计北大核心

在通信侦察识别中,通信信号的码元速率估计是调制识别和信息解调的前提和基础。针对直接序列扩频信号的伪码码片速率估计问题,提出了一种利用联合循环高阶累积量非对角1-D切片特征参数,对直扩信号码片速率进行盲估计的改进算法。该算法将采样信号不同延时的非对角1-D切片进行联合处理,通过自相关、快速傅里叶变换、求模平方等方法,增强了谱线特征。仿真实验证明,改进算法较2-D切片算法简化了计算,并且在更低信噪比条件下,实现了对无先验信息直接序列扩频信号的码片速率盲估计。     

误差配准在两种纯距离定位算法的应用比较

组网雷达系统中,由于观测信息量的增加,对目标存在多种定位算法。很多情形下,误差配准公式是基于某一定位算法推导而来,误差配准的结果也相应的用来提高此定位算法的定位精度。定位算法的复杂程度不同导致基于此算法推导误差配准公式难度不一致,不同定位算法的定位精度也不尽相同。因此,对两种多距离定位算法的定位精度、误差配准推导难易程度进行了理论分析和仿真计算,给出了定位精度的解析表达式和仿真结果。利用表达式简单的定位算法推导基于最小二乘的误差配准公式,并将误差配准结果反馈给定位精度高的定位算法,以最大程度提高误差配准结果的应用效果,减轻计算复杂度,提高信息的利用度。     

基于测向角的飞行器无源定位模型及模拟计算

飞行器无源定位技术的关键是建立定位模型及其快速优化算法。研究了基于地球同步卫星与飞行器测向阵列之间方向角的无源定位技术。利用空间向量分析方法和最小二乘法,在多颗观测卫星的情况下提出了飞行器的静态定位数学模型;在观测卫星较少,且飞行器处于运动状态的情况下,提出了飞行器的动态定位数学模型。借助对相关参数的假设和搜索算法,分别对2个模型进行了模拟计算,较好地实现了2种情况下飞行器的无源定位。     

基于算子空间的公式发现算法研究

在FDD提出的人工智能技术与曲线拟合技术结合的公式发现系统的基础上 ,提出了新的基于算子空间的公式发现算法 ,并在算法研究的基础上设计实现基于算子空间的可视化公式发现系统 ,该系统通过算子空间概念的引入 ,简化了算子空间的规则 ,同时引入导数规则、误差规则以及终止规则 ,丰富了知识库内容。通过以上改进 ,和BACON和FDD相比 ,公式发现的形式更广 ,复杂度更高。文章最后给出了应用实例以及公式发现的结果。     

基于时间切片的通信计划合规性评估模型

针对体系作战背景下通信计划规划任务多线性和关系复杂的问题,提出了一种通信计划合规性评估模型。该模型通过构建计划时间切片,描述了多个通信保障任务主线在各阶段的全局关系视图,并定义了通信链路连接矩阵、电磁频谱三级规划和指控系统命名类量化,描述了通信计划的基本内容,同时定义了3类评估规则和3种评估运算法则,形成了完整的合规性评估体系。最后,通过实例分析验证了模型有效性,结果表明,评估模型能够较好地区分不同信息需求下的通信计划合理程度。     

阵列增益下的最大听觉距离及算例分析

被动声定位技术已成为战场目标定位的重要手段,人-机一体化头盔式"电子哨兵"系统能够解决阵列信号处理低信噪比性能下降及人耳听觉距离有限的缺点。作为系统研发的理论基础,从声传播方程出发,研究了考虑阵列增益条件下的最大听觉距离。基于声传播方程,分析了声传播损失的计算方法,探讨了自由场情况下和存在阵列支撑物情况下阵列常规增益和阵列超增益的算法,最后通过算例对阵列处理提高人耳听音距离进行了说明,为人-机一体化"电子哨兵"系统研发提供了理论依据。     

双站测向交叉定位精度分析

测向交叉定位作为一种无源定位技术而受到高度重视。通过阐述双站测向交叉定位原理,推导了该法的定位精度公式。在此基础上利用仿真实验分析了单站测角精度、站点坐标精度和基线长度等因素对定位精度的影响。研究结果为该类系统的技术作战运用提供了理论支持。     

流动粉浆输送装置的研究

为减轻环卫工和建筑工人劳动强度和提高工作效率,在已有螺旋输送机的工作原理基础上,进行创新。将螺旋片由刚性连接改为柔性连接,将硬管改为软管。经过试验,在选择了一定的工艺参数后,使刚性的螺旋片和柔性的胶管之间,有较好的配合效果,从而实现了螺旋输送机械,可以在输送管道有一定弯曲的条件下,运送砂浆的功能。该研究有一定的实用价值和社会意义。加工制造工艺不复杂,有利于普及。     

一种快速有效的循环平稳信号检测方法

TSAE-Z算法把时间切片自相关包络检测和可变步进的Zoom-FFT检测相结合,实现了对循环平稳信号的快速、精确检测,仿真结果表明,在相同数据长度条件下,TSAE-Z算法能够使检测运算时间减少3个数量级;在相同执行时间的条件下,TSAE-Z算法能在提高检测分辨率的同时使检测性能提升6dB以上。     

黑腿星翅蝗（Calliptamusbarbarus）消化道组织结构观察

应用常规石蜡切片法，H·E染色，在光学显微镜下对黑腿星翅蝗（Calliptamusbarbarus）消化道组织结构进行了观察。结果表明，黑腿星翅蝗消化道壁由内向外的组织结构是：最内层为几丁质内膜或围食膜，然后依次为上皮层（肠壁细胞层）、基膜、环肌层、纵肌束和围膜。其中前肠和直肠的最内层具有非细胞结构的几丁质内膜，中肠则具有非细胞结构的围食膜，直肠部位具有6个直肠垫。消化道的组织学结构与蝗虫的一般结构相似。     

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).     

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.     

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.     

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.