N个不同部件并联可修系统的可用度分析

由N个不同部件并联组成系统,各部件失效率分别为(λ1,λ2,…,λn),修复率分别为(μ1,μ2,…,μn).假定在Δt时间内系统不会同时出现两个以上部件失效,若只有一组维修人员且不能同时修复两个以上失效部件,根据基于马尔可夫过程的系统状态转移图,则共有(n 1)个状态.     

基于可修复条件下无人机系统可用度研究

可用度是战备完好率的重要指标,可用度受可靠度和维修度综合影响,用状态转移的方法分析了装备可用度,并在无人机系统可修复条件下,针对无人机系统故障问题,对其可靠度、维修度进行权衡,以确保系统战备完好率。     

多级保障设备寿命期内的可用度模型

针对具有三级维修机构保障的复杂设备,在小修修复如旧、中修大修均可使设备年轻固定时间的假设下,通过对设备使用和修理流程分析,给出了设备寿命期内的使用与修理状态转移图,建立了设备寿命期内的维修间隔期与可用度关系模型,求出了设备在固定的维修间隔期和一定维修转换规则下的平均可用度。案例分析得到了使可用度达到最大时的设备最佳维修间隔期,并通过与大修修复如新进行比较,说明了模型的适用性与灵敏性,可为设备维修决策提供依据。     

舰载机着舰引导装备体系系统级备件保障研究

针对舰载机着舰引导装备体系中备件构成复杂、数量众多,传统单元级备件保障效果单一,无法高效、全面评估整个备件系统的问题。引入k/N(G)表决关系把复杂系统等效分解为串并联结构;提出备件保障概率、使用可用度、利用率等关键性指标在不同种备件寿命分布类型下的预测模型,针对任务结束后才能统计得出指标数据的不足,利用解析计算方法实现预先评估备件方案,提高备件保障效果;并进一步给出系统级各指标计算方法。通过算例分析,与传统方法相比提高了该体系系统级备件保障方案制定的精度与综合评估能力,同时仿真结果符合实际情况。     

考虑维修优先权的多状态冷储备系统可靠性模型

针对多状态两部件冷储备系统存在多类维护方式的情况,假设系统中的单维修台能够根据部件状态提供保养和维修两类服务,其中维修具有更高的优先级。采用连续Phase-type分布代替指数分布等典型分布,描述工作部件在不同性能水平的停留时间、维修台保养和维修时间。利用矩阵解析方法获得了系统稳态概率,推导出系统稳态可用度、系统工作时间、系统平均停机间隔时间、维修台故障件到达率和系统故障率等参数的解析表达式。通过算例验证了模型的正确性和适用性,演示了保养和维修速率对系统各可靠性参数的影响。研究结果表明,利用Phase-type分布对多状态系统开展可靠性解析建模,能够在确保良好解析特性的同时,有效提升模型的描述能力,从假设条件环节保证模型具有更强的通用性。     

舰载机着舰引导装备体系系统级备件保障

针对舰载机着舰引导装备体系中随舰备件存在补给周期长、难度大的问题,对舰载机着舰备品备件保障 进行研究。详细阐述备件保障关键指标及计算方法,引入k/N(G)表决关系把复杂系统等效分解为串并联结构,构建 关键性指标在不同种备件寿命分布类型下的预测模型,分析备件保障概率、使用可用度以及利用率等随着备件数量 的变化规律,利用解析计算方法实现预先评估备件方案,并通过算例对算法进行验证。分析结果表明：该方法优化 了备件方案,提高任务完成度与经济性,同时为预先制定合理的备件方案提供参考,具有较高的应用价值。     

应用k／n（G）系统设计方法提高串行通信可靠性分析

论述了k／n(G)系统设计的原理，说明了k/n(G)系统设计在串行通信中的应用，通过分析计算说明串行通信采用k／n(G)系统设计方法可极大地提高串行通信的可靠性，避免通信误码导致的测试故障，以提高测试发射系统的可靠性。     

考虑不同维修效果的多状态可修系统可靠性模型

为了研究不同维修效果下多状态可修系统的可靠性模型,考虑修后恢复修前状态、维修效果较差和维修效果好3种不同维修效果,假设系统工作状态可以划分为完好和一般两类,系统工作时间和维修时间服从连续Phase-type分布,建立系统状态马尔可夫转换的无穷小生成元矩阵,求得各状态稳态概率向量,给出了系统稳态可用度、稳态故障率的解析表达式。通过算例验证了该模型的有效性和适用性。     

评估复杂可维修系统可靠度与瞬态可用度的蒙特卡罗方法

本文设计了评估复杂可维修系统可靠，瞬态可用度的蒙特卡罗方法，该方法利用Bootstrap方法作为框架，在计算可靠度和瞬态可用度的点估计时采用加权统计估计蒙特卡罗方法。通过评估一周期维修的非马尔可夫系统的可靠度和瞬态可用度检验了本文方法的适用性。     

作战单元装备稳态可用度评估模型及其求解算法研究

针对作战单元可用度研究中存在的问题,建立了基于多维Markov过程(MDMP)作战单元装备稳态可用度模型,并针对MDMP状态较多的问题研究了其降维求解算法。该模型中考虑了作战单元中的多个装备;该算法利用部件的维修资源相关性来降低问题的维度。研究结果表明,MDMP的解析建模具有比较全面的建模能力,可以对作战单元可用度问题进行建模;利用不同部件之间的关系信息设计的降维算法能够减少不必要的计算量。最后通过一个算例说明了模型和算法的实用性。     

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.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

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.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

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.     

Design and Implementation of One Missile Visual Simulation System Based on OpenGL

The implementation of a missile＇s visual simulation system is explained that is developed with OpenGL（open graphic library） and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile＇s data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.     

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.     

Dynamic Encryption Technology in Ad-hoc Networks

A new dynamic encryption application in ad-hoc networks is proposed. The advantages of this method are its being able to use the previous ciphertext as a seed of a new encryption process, rendering the encryption process effective in all communication process by continuous dynamic key generation together with synchronization, and its capability to cut back on system bandages to a greater extent, which is valuable for the ad-hoc circumstance. In addition, the rationality and effectiveness of this novel encryption method have been verified by the test results.     

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.