飞航导弹雷达截面预估

综合应用物理光学法（PO）、等效电磁流法（MEC）和几何光学法（GO）等高频分析方法,分析了导弹目标各部分散射场之间的相互干涉作用,计算了椭球体弹头、橄榄体弹头和半球体弹头三种不同形状弹头的导弹整体雷达截面（RCS）。计算结果表明该方法正确有效,可满足工程分析的需要。     

The grand plans [ballistic missile defense]

The United States plans to use a layered approach to protect its forces and allies against short-range ballistic missiles, which have ranges less than 3500 km. Area defenses such as the land-based Theater High Altitude Area Defense (Thaad) and the sea-based upper-tier defenses will cover broad areas. Patriot PAC-2 and PAC-3 and the sea-based lower-tier defenses will be a backup for targets missed by the upper tier and protect high-value targets such as airfields, ports, headquarters, and population centers. The Airborne Laser will aim to destroy missiles during the boost phase, when their rocket motors are burning and before they can deploy warheads, decoys, or submunitions. A theater battle management system will coordinate the system's many components     

基于滑窗MCMC的弹道导弹分导团目标数据关联研究

弹道导弹在再入过程中为了提高自身突防能力往往伴随着分导现象。由于分导弹头数目未知,距离目标近且再入速度非常相近,使其以团状形态运动,在未知导弹任何先验信息前提下如何对分导弹头进行快速关联已成为亟待解决的难题。该文提出了一种改进的实时滑窗马尔可夫链-蒙特卡洛(Markov Chain Monte Carlo,MCMC)次优数据关联算法,它应用蒙特卡洛采样方法对监控区域的测量集合进行组合优化,获得最大的后验概率密度进而逼近马氏链的平稳分布。该算法结合弹头分导实际情况,重新分配关联假设权值并优化了继承性,极大地减小了关联时间。仿真结果表明该算法与经典的多假设算法相比,关联概率随着目标密集程度增加而显著提高,并且计算量远小于多假设算法。     

基于底部排气弹的多重命中体制

希望常规高炮在拦阻射击时能够多重命中,而这种命中体制的本质是通过改变初速来达到控制弹头飞行时间,使其满足多重命中的条件,但是由于固定的、多级分号装药、次序发射,而不能在任选的瞬时实现同时命中,影响了它的适用性,因此提出一种基于底部排气弹的多重命中体制,并进行了理论分析,核心是通过控制底排延时点火时间,使弹头的飞行时间曲线满足多重命中条件,从而实现顺序发射的多发弹头同时命中目标.给出了问题求解的实现算法,此算法的核心是求解一个射角未知、终点受约束的两点边值问题,最终目的是获得同频射击条件下的底排延时点火时间.最后的仿真结果表明基于底排的多重命中体制具有可实现性,对发掘常规高炮的潜力有积极作用.     

弹头形状对导弹RCS影响的分析

对导弹的结构进行简化,建立了导弹的电磁散射模型,通过综合运用物理光学法（PO）、等效电磁流法（MEC）、几何光学法（GO）等高频方法计算了导弹模型各散射中心的雷达散射截面积（RCS）,并考虑目标各部分散射场间的相对相位关系,计算了带橄榄型弹头导弹的整体RCS,其结果与参考文献的实测结果吻合较好,这说明该文的分析方法是正确的、有效的,结果可满足工程预估的需要。在此基础上,分别计算了不同极化方式下带椭球型和半球型弹头导弹的RCS,结合RCS曲线分析了弹头形状对导弹电磁散射特性的影响。     

基于ISAR像序列的弹道目标进动特征提取

中段弹道目标进动特征是分辨弹头及诱饵的重要依据.以二维ISAR图像序列为基础,分析了弹道目标成像特点和目标姿态角的变化过程,提出了基于图像配准的ISAR像姿态差估计方法;采用等间隔配准避免了配准奇异,根据姿态差二次方曲线实现了进动参数的估计,给出了计算目标进动角、进动周期的具体步骤.仿真结果表明,该方法能够实现弹道目标进动特征提取,估计精度较高.     

微进动弹道导弹目标雷达特征提取

该文总结了弹道导弹目标雷达识别的研究现状,引入微进动和微RCS的概念,推导了进动锥体目标对雷达波的姿态角计算公式,分析了微RCS和姿态角的关系,使用进动锥体目标的微RCS序列估计目标进动参数和惯量比。以惯量比为特征,提出了识别弹头和诱饵的方法。最后给出了仿真结果。     

Secrets of the Soviet nuclear complex

Hundreds of thousands of engineers, scientists, and workers found employment in the nuclear complexes of the former Soviet Union. Now, in the aftermath of the USSR's demise, details of its nuclear-industrial complex are coming to light. The huge industry which descended from the notorious gulags must now dispose of myriad warheads, fissile materials by the tonne, plus reactors. The author describes this secretive Soviet industry     

What About The Nukes?

The United States' thousands of nuclear warheads have the explosive equivalent of over 1 gigaton of TNT. It's an amount of energy that could literally move mountains, reroute rivers, alter climate, and result in the deaths of hundreds of millions or even billions of people, through fire, radiation, and starvation.     

ARM破片式战斗部对地空导弹制导雷达毁伤研究

针对反辐射导弹对地空导弹制导雷达的毁伤机理和强度进行分析和理论研究,提出求解破片式战斗部对制导雷达毁伤概率的数学模型和计算方法.对地空导弹制导雷达进行功能和结构分析,推导出战斗部破片的毁伤机理,根据破片毁伤过程建立破片对制导雷达的毁伤模型.综合考虑强度极限和剪切应力,建立相对全面的等效靶厚度计算模型.利用模糊集理论建立...     

How to lengthen the nuclear fuse

Presidents Clinton and Yeltsin took a step toward de-alerting strategic nuclear forces in 1994, when they pledged to stop aiming strategic missiles at each other's country. But the pact was symbolic only. The missiles retained their wartime targets in computer memory, and the target coordinates could be reloaded into the missile guidance computers within seconds. If either President ordered a missile attack, the message would be transmitted in seconds to land-based launch crews and in minutes to submarine crews. Thousands of warheads could be launched within 30 minutes or so of the initial decision. A stand-down from this strategic forces alert-a lengthening of the launch readiness of the missiles from minutes to hours or days or longer-would do in reality what the de-targeting step did symbolically. It would end an anachronistic state of affairs-the fact that, a decade after the end of the Cold War, the United States and Russia are still maintaining nuclear weapons on hair-trigger alert aimed at each other's nuclear forces and cities. The authors discuss the alert status of the nuclear forces, pressure for fast launches, and the path to de-alerting, and a de-alerting scenario     

中段目标进动雷达特征提取

本文总结了弹道导弹目标雷达识别的研究现状,推导了进动锥体目标对雷达波的姿态角计算公式,分析了目标RCS和姿态角的关系,使用进动锥体目标的RCS时间序列估计了目标进动参数和惯量比,使用惯量比作为特征,提出了识别弹头和诱饵的方法,最后给出了仿真结果。     

基于弹道目标的发射事件管理技术研究

弹道导弹在整个飞行过程中具有多种飞行状态,同时在每个飞行阶段会产生弹头、弹体以及其他伴飞物;当进行多枚弹道导弹齐射时,将产生大量的数据,其结果为数据处理中心准确获取导弹发射次数、目标航迹数据处理和为武器系统拦截提供有效拦截目标产生巨大不确定因素。因此,通过开展发射事件管理技术研究,可以有效解决以上问题。该技术 通过时间-空间关联算法、导弹定轨关联算法和导弹分离事件关联算法,实现对空间中不同目标进行关联,将属于同一发射事件的不同目标关联为同一次发射事件,并给出同一发射事件中的主目标,为目标识别系统和武器系统进行重点目标识别和拦截提供重要支撑。试验结果表明了该技术的有效性。     

Two-dimensional electrophoresis image interpretation

A method for interpreting two-dimensional electrophoresis gels is presented. Genetic background and electrophoretic processes are summarized, and present methods for analyzing gel images and exploiting series of gels are described and their drawbacks outlined. Artificial intelligence techniques are introduced to build and image interpretation system which can compensate for certain failures of present methods and augment their efficiency. By reproducing methods of biological experts, this system automatically identifies proteins-whether isolated or inside constellations-on an electrophoretic gel. This system is based on a modular architecture, featuring image processing procedures, which allows extraction of parameters from the image and a top-down and bottom-up reasoning process. The reasoning process first matches extracted parameters to possible geometric models of proteins; it then returns to the image to determine possible missing elements on the gel. A prototype of this system was implemented and tested on plasma gels to identify apolipoproteins     

光缆CATV干线传输系统技术性能的分析

文章系统地分析和讨论了光缆ＣＡＴＶ干线网络传输系统主要技术指标．Ｃ／Ｎ、ＣＴＢ、ＣＳＯ与系统各组成部分技术性能参数间的关系，给出了有关的表达式，对熟悉、了解光缆ＣＡＴＶ传输系统和传输系统的工程设计，实用化研究等有一定的参考意义。     

Analysis of multiplex techniques for land mobile radio service

Two types of frequency multiplexing are theoretically analyzed for their applicability as a form of modulation in the land mobile radio service (LMRS). Both SSB/FM and FM/FM are analyzed for their signal-to-noise ratio (SNR) versus modulation index. These results are normalized to the signal-to-noise performances of the existing 5-kHz deviation system for comparison purposes. The latter performance is developed using the actual Electronic Industries Association (EIA) response of a LMRS receiver. The spectrum of the multiplex system for the case of equal subchannel signal-to-noise is developed using a computer. The spectrum is used to determine the spectrmm occupancy of multiplex systems. Based on the tradeoffs of transmit power and spectrum occupancy, a discussion of the interference characteristics of the multiplex systems compared to the existing system is presented. Finally, conclusions are drawn on the spectrum efficiency of a multiplex system compared to the present system.     

Least Squares Identification for Hammerstein Multi-input Multi-output Systems Based on the Key-Term Separation Technique

System modeling and parameter estimation are basic for system analysis and controller design. This paper considers the parameter identification problem of a Hammerstein multi-input multi-output (H-MIMO) system. In order to avoid the product terms in the identification model, we derive a pseudo-linear identification model of the H-MIMO system through separating a key term from the output equation of the system and present a hierarchical generalized least squares (LS) algorithm for estimating the parameters of the system. Moreover, we present a new LS algorithm to reduce the computational burden. The proposed algorithms are simple in principle and can achieve a higher computational efficiency than the over-parameterization-based LS estimation algorithm. Finally, we test the proposed algorithms by the simulation example and show their effectiveness.     

扩散光层析成像系统研究现状及发展

对国内外有关扩散光成像系统进行总结分析,将成像系统分为三大部分,对每部分进行分类并分析了各自的优缺点。分析介绍了国内外具有代表性的扩散光层析成像系统,总结了成像系统存在的问题。     

END: an expert network designer

Professional designers with intensive knowledge and experience are needed for large computer network design and optimization. Such designers must be well informed about the most recent up-dates in this rapidly advancing field to be able to handle the available state-of-the-art technologies. Since designers of such caliber are difficult to find and usually very expensive, the present authors propose the use of expert systems to play their role and/or assist them in their task. The authors discuss: system architecture and functionality, the OPNET network simulation package. They also present various network design examples     

A digital video system for the automated measurement of repetitive joint motion

Automated measurement and analysis of human motion during performance of workplace tasks are desirable for ergonomic studies. While numerous technologies exist for accurate measurement of biomechanical data, their use is often not feasible in the workplace environment. We present a digital-video based system suitable for measuring human motion of repetitive workplace tasks. Due to practical considerations, a single-camera solution is exploited by adding some control over the environment. We present an analysis of experiments demonstrating the accuracy of our system.