并行程序调试中的环境再现技术

为解决调试并行程序碰到的第一个困难:并行程序的不确定性,文中提出了环境再现技术。文中叙述了环境再现技术的思想和实现这一技术需要的数据结构,并用CCNPASCAL语言进行了描述,最后给出了一个典型的应用例子。     

双二体几何切面法及天梯地月转移轨道分析

双二体模型是求解地月转移轨道的重要基础。与传统的采用月球影响球入口点经纬度的描述方式不同,本文提出一种基于飞行轨道面参数来描述地月转移轨道的双二体模型几何表达方式,结合一维非线性方程求根算法Brent算法和Lambert原理,将原始三维球面搜索算法降维成为二维圆上的搜索算法,可以高效求解地月转移轨道的形状参数。为避免重复计算,将转移轨道窗口计算的轨道多变量搜索问题解耦分解成两个子问题——转移轨道形状参数求解问题和转移轨道面空间定向问题,降低了问题的求解维度。形成两级并行计算算法,充分发挥多核计算机算力,加速计算过程。仿真结果表明,基于提出的并行圆锥曲线几何切面法,可以成功应用于计算天梯地月转移轨道分析。     

双圆阵模式空间二维解相干

提出一种相干信号二维波达方向(Direction of Arrival,DOA)估计算法——模式空间波达方向矩阵(Mode-Space DOA Matrix,MS-DOAM)法。算法基于双圆阵,利用模式空间转换将圆阵转换为虚拟双平行线阵,计算虚拟线阵阵元间的互相关信息,构造两个等效协方差矩阵,进而构造波达方向矩阵,对该波达方向矩阵特征分解,利用得到的特征值与特征矢量求得入射信号的仰角和方位角。算法无需二维搜索,实现估计参数自动配对。仿真结果表明,算法在低信噪比和短快拍条件下,估计误差低于虚拟空间平移算法。     

未来中远距协同空战多目标攻击决策研究

根据先进战斗机的技术特点和未来中远距协同空战发展方向,提出一种基于先敌发现、先敌发射、先敌摧毁能力的空战态势分析模型。同时,采用一种将并行遗传算法与分布估计算法相结合的并行分布遗传算法并将其用于多目标攻击决策。最后利用具体算例进行仿真。结果表明空战态势分析模型能够较为准确地描述未来中远距多机协同空战,采用的算法具有较好的可行性和实时性,为中远距多机协同空战的多目标攻击决策提供了新的思路和方法。     

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established. According to the relation of the dynamic seven photoelectric detection screen planes and the time values, the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.     

基于准循环双对角阵的LDPC码编码算法研究*

针对校验矩阵形如准循环双对角阵的结构化LDPC码,对比研究了两类高效的编码算法：矩阵分解编码算法和分项累加递归编码算法,指出了两种算法从实现角度是等效的,但分项累加递归编码算法推导更为直观,且便于硬件并行实现。基于分项累加编码算法,提出了一种适合准循环双对角LDPC码的部分并行编码结构,设计实现了IEEE 802.11n标准中的LDPC码编码器。FPGA实现结果表明,所设计的LDPC编码器硬件开销较少,信息比特吞吐率最高能达到13Gbps。     

太阳能电池阵跟踪驱动过程扰振特性分析

太阳能电池阵对日跟踪驱动过程所产生的扰动是限制高精度航天器技术指标提高的主要因素之一。为获取驱动扰动的规律性特征,本文将太阳能电池阵及其驱动装置考虑为相互耦合的整体系统,从主要驱动环节出发建立其机电一体化扰振分析模型和Simulink动力学仿真模块,通过试验算例验证模型正确性,并分析了电池阵刚柔耦合和质心偏置等因素对扰振特性的影响。结果表明:转速波动将激起电池阵低阶扭振模态,扰动频谱具有步进电动机驱动和柔性结构振动的频率特性,但扭振扰动对刚体运动规律影响很小;质心偏置会引起电池阵平动与转动耦合的空间振动,激扰面外弯曲振型,改变扰振频率分布和放大扰振分量幅值。     

Conceptual failure,the Taliban's parallel hierarchies,and America's strategic defeat in Afghanistan

ISAF exists to protect the Afghan constitutional model. This strategic objective will be defeated because the GIRoA model has a conceptual flaw that renders it incapable of delivering governance at the local level (Tier IV). This fatal flaw has enabled the Taliban, by developing parallel hierarchies, to displace GIRoA and establish itself in southern locales as the political authority. The Taliban are fighting a revolutionary war, a Maoist displacement strategy that uses guerrilla tactics to advance a political program. Petraeus and McChrystal failed to recognize the character of war, and believed the Taliban are pursuing an exhaustion strategy. They failed to devise a counter-RW strategy. The ‘Surge’ was doomed ab initio.     

基于平行坐标的多维复杂数据可视化方法研究

随着各种传感器、雷达以及卫星等信息收集设备在军事领域中的广泛应用,能够实时地对战场进行全方位多角度的监控,在获得大量的战场信息数据的同时,信息处理的难度也大大的提高了。为了解决这一问题,对在多维数据融合、可视化领域中广泛用到的平行坐标技术的产生、发展和应用进行了研究,并利用地质多维数据对该方法进行了应用实验,给出了实验结果和分析。最后,结合军事领域中数据融合的概念对本方法做了一定的论述,以期能为炮兵、防空兵信息处理领域提供一定的理论参考。     

R^3,1中具有平行平均曲率向量的类时曲面

用可积系统方法给出了4维Minkowski空间R^3,1中具有平行平均曲率向量的正则类时曲面的表示。与类空曲面不同,这些类时曲面由Klein-Gordon方程ωxy＋｜H｜sinhω=0,ωxy-｜H｜coshω=0,ωxy＋1/2｜H｜eω/2=0所决定,表明这类曲面在R3,1中是丰富的。