基于马尔可夫链的军用Ad hoc网络可用性建模

军用通信网络的规模和复杂程度日益扩大,迫切需要一种高可用性网络来满足用户对高可靠服务的需求,而网络可用性的定量研究,对战术通信网络可靠性能评估具有重要意义。针对战术Ad hoc网络的移动和故障因素,建立了基于马尔可夫链的网络可用性模型,通过分析带有冲突避免的载波侦听多路访问传输机制,研究影响网络业务主要因素的延时模型。在此模型基础上,根据统计学原理,提出一种基于故障的移动Ad hoc网络业务可用性定量评估模型。以某典型陆军战术分队通信网为例,分析了网络可用度与节点个数、传输速率、报文长度等核心指标的关系,通过仿真验证了分析结果的有效性。     

Ad Hoc网络移动模型研究

Ad Hoc网络是一种临时快速自动组网的移动通信技术,广泛地应用在军事通信与应急通信中;网络节点移动模型是Ad Hoc网络研究的基础,在多数现实情况中节点的运动是有规律的,并随之出现了许多不同的移动模型;对现有移动模型进行了分析梳理,总结了移动模型存在的问题并指出其发展方向,对Ad Hoc网络研究具有一定的参考价值.     

对Ad Hoc网络通信干扰效能评估研究

Ad Hoc网络在战场信息网络中的广泛使用使得研究Ad Hoc网络通信干扰效能评估成为网络战研究的重要内容.本文中分析了对Ad Hoc网络通信干扰效能评估的基本流程,初步建立了效能评估指标体系,提出了用层次分析法确定指标权重的方法和效能综合评估模型.     

想定环境中对战术互联网性能评估方法的研究及实现

战术互联网不同于其它Ad hoc网络的根本特点是应用于战场环境当中，但目前对战术互联网性能的仿真评估方法却没有反映出战场特定的因素，如地形、战术行动等对其性能的影响。针对此问题采取想定作业的方法体现战场环境因素，使用了自主编写的战场指挥通信过程模拟软件TCSS，以FSR路由协议为例进行了仿真实验。测试结果表明，战场因素很大程度地影响了Adhoc网络路由协议的效率，实验数据为战术互联网系统的构建提供了重要的参考。     

对Ad Hoc网络通信干扰效能评估研究

Ad Hoc网络在战场信息网络中的广泛使用使得研究Ad Hoc网络通信干扰效能评估成为网络战研究的重要内容．本文中分析了对Ad Hoc网络通信干扰效能评估的基本流程，初步建立了效能评估指标体系，提出了用层次分析法确定指标权重的方法和效能综合评估模型．     

基于蚁群算法的Ad hoc网络节点信息感知路由研究

针对Ad hoc网络易出现拥塞,路由查找过程较慢,将蚁群算法应用到Ad hoc网络的路由选择问题上,提出一种基于网络节点链路拥塞度和识别目的节点信息素的Ad hoc网络路由算法。该方法根据网络中链路拥塞度值来修改信息素的挥发因子,并利用其进行蚁群信息素浓度更新,使路由选择与网络参数相关联,实现拥塞控制。仿真结果表明:该算法在分组交付率和平均端到端延迟等方面都有一定的改善。     

基于OPNET的Ad Hoc网络建模与仿真

基于OPNET网络仿真平台,建立了Ad Hoc网络节点的仿真模型.通过仿真实验,获得了不同情况下的网络性能指标参数,从而为Ad Hoc网络的研究与设计提供了一种新的途径.     

定向含能动能杆战斗部毁伤效能评估模型研究

定向含能动能杆战斗部是一种新型反战术弹道导弹战斗部.为了科学评估定向含能动能杆战斗部的毁伤效能,分析了影响定向含能动能杆战斗部毁伤效能的相关因素,建立了毁伤效能综合评估指标体系,提出了一种基于端点三角白化权函数的灰色聚类战斗部毁伤效能评估模型;以美国M39战术弹道导弹再入弹头为研究对象,分析了定向含能动能杆战斗部对其的毁伤效能,通过算例,验证了评估模型的合理性.     

GRID路由协议的安全性研究综述

移动Ad Hoc网络中路由协议的安全性是目前的研究热点。概述了移动Ad Hoc网络的特性和GRID路由协议的转发特性,分析了移动Ad Hoc网络存在的安全问题,总结了基于身份信任和行为信任的安全方案的研究现状。结合身份信任和行为信任,对提升GRID路由协议的安全性提出了改进方案。     

基于改进ADC法的高空气象探测系统效能评估

针对遂行高空气象探测任务的高空气象探测系统缺乏有效定量评估模型的问题,结合高空气象探测系统的单元组成及特点,构建了基于灰色理论层次分析法的ADC静态作战性能评估模型,并对系统的可用性、可靠性和系统能力进行了具体分析;通过实例计算分析,该模型的计算结果与实际情况下专家评估所得的结论相符,为定量评估高空气象探测系统作战效能提供了一种有效途径。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.