一种改进粒子群算法优化BP神经网络实现核素识别方法

为获得全局最优点,提出一种改进粒子群算法优化BP神经网络实现核素识别方法.该算法用一种动态改变惯性权重与学习因子的自适应方法,优化BP神经网络的阈值与权值,通过训练BP神经网络识别模型得到粒子群的全局最优解,利用最优权值与阈值实现核素识别.分析结果表明:该方法不仅能更快地收敛于最优解,同时能更好地平衡全局搜索和局部搜索能力,有效地改善算法的收敛速度和识别精度.     

遗传算法优化BP神经网络在转速PID控制中的应用

提出一种基于遗传算法优化的BP神经网络PID控制算法，并将其应用于永磁无刷直流电动机的转速控制系统而设计出优化的转速PID控制器。该算法首先利用遗传算法对BP神经网络的初始权值进行优化，再利用BP神经网络算法对PID参数进行在线调节，解决网络的初始权值对控制效果的不利影响，仿真证明该算法可行。     

基于自适应混沌变异粒子群优化算法的旋转弹丸气动参数辨识

将最大似然准则应用于高速旋转弹丸的气动参数辨识问题中,提出一种新的自适应混沌变异粒子群算法求解该准则下的气动参数最优解,进而得到弹丸的气动参数。该算法通过自适应调整惯性权重、利用混沌优化的思想产生初始粒子、设定早熟判别机制来判断是否陷入局部最优解,并通过粒子变异的策略使其跳出局部最优解等方法进一步优化基本粒子群算法。通过常用的测试函数对该算法进行了测试,测试结果表明：相比于基本粒子群算法,该算法具有收敛速度快、寻优精度高、应用范围广等优点。利用系统仿真的方法模拟弹丸的自由飞行数据,并利用该数据结合所提算法对弹丸的主要气动参数进行辨识,辨识结果表明：该算法可以有效辨识弹丸的气动参数,且精度高,收敛速度快,可以应用于工程实际问题。     

一种基于炮射地面震动传感器的目标识别算法研究

介绍了自适应遗传算法优化的BP神经网络(AGA-BP)算法在炮射地面震动传感器目标识别中的应用。首先针对BP神经网络可能未收敛到全局最小点的缺陷,提出自适应遗传算法与BP神经网络结合的一种优化算法。之后进行仿真实验并对履带和轮式车辆的采样信号进行时频分析,利用小波变换提取特征值。最后利用优化后的算法与传统算法进行了样本训练和识别,对比结果表明该方法能减少识别误差。     

基于改进GA优化的神经网络故障诊断方法

在改进遗传算法和BP算法的基础上提出了一种普适的遗传算法与神经网络结合的算法模型.探讨了用改进的遗传算法与BP算法相结合对神经网络权系数进行优化;并将其应用于交流电机故障识别.实践表明,该方法是一种行之有效的智能故障诊断新途径.     

粒子群优化算法在传动箱故障诊断中的应用

基于粒子群优化算法（PSO）的神经网络具有良好的训练性能，输出的整体误差小于BP算法。用PSO作为一种粗优化或离线学习过程，用神经网络学习作为一种细优化或在线学习过程。这两种方法综合使用可以大大提高传动箱故障诊断性能。诊断系统把常用的7个时频动态特征参量作为BP网络的输入层的输入，把传动箱中常见的6种特征作为网络的输出。诊断系统拓扑结构为7—12—6的3层BP网络，规定系统误差0．001。结果表明．粒子群优化算法对多故障征兆有较好的故障识别率。作为一种有效优化方法，在机械故障诊断领域具有良好的应用前景。     

基于麻雀搜索算法优化BP神经网络的弹丸射程预测研究

弹丸发射参数、气象条件等会影响弹丸射程,其构成的影响体系复杂并难以准确预测。针对BP预测算法会因初始权值和阈值取值不当导致陷入局部最优的问题,建立了麻雀搜索算法(SSA)优化BP神经网络的弹丸射程预测模型,以弹丸射程作为输出指标,选取弹丸初速、发射角度和风力条件作为影响因素输入,经过数据预处理后进行弹丸射程预测;同时与粒子群算法(PSO)和遗传算法(GA)优化BP神经网络预测模型的预测精度进行对比,验证SSA优化BP神经网络模型的预测效果。结果表明,SSA-BP预测模型的平均绝对误差、均方根误差和平均绝对百分比误差分别为10.456 4 m、11.831 3 m和0.058 13%,低于BP、PSO-BP、GA-BP预测模型的相应评估指标,所以SSA-BP模型的预测精度高于BP、PSO-BP、GA-BP预测模型,其可以为弹丸射程预测和远程火力打击研究提供支持。     

基于粒子群神经网络的含硼富燃料推进剂一次燃烧性能计算

使用粒子群算法(particle swarm optimization,PSO)来优化误差反传(back propagation,BP)神经网络的权重和阈值,建立了粒子群神经网络(PSO-BP)计算模型,利用该模型对含硼富燃料推进剂的一次燃烧性能进行了模拟计算,当端羟基聚丁二烯(HTPB,28％ ～32％)、高氯酸铵(...     

BP神经网络结合粒子群优化卡尔曼滤波的MEMS陀螺随机误差补偿方法

针对微机电系统(MEMS)陀螺仪随机误差相对较大、影响其精度这一问题，提出一种基于BP神经网络结合具有量子行为的粒子群优化(QPSO)算法优化卡尔曼滤波(KF)的补偿方法。采集MEMS陀螺和转台数据作为样本，采用BP神经网络进行训练，建立误差模型；利用训练好的模型对MEMS陀螺进行误差补偿；利用QPSO算法优化KF,以达到更好的降噪效果。实验结果表明，该方法较BP神经网络优化KF、QPSO优化KF与变分模态分解结合小波阈值去噪等方法去噪处理后的平均绝对误差(MAE)和均方误差(MSE)更小，具有更好的降噪效果。     

基于模糊神经网络的非线性系统辨识

基于神经网络的预测控制器由神经单元自适应PID控制器和基于神经网络的Smith预估器组成.预估器对输出进行多步预测,使控制器超前动作以消除时滞对系统的影响.自适应PID控制器通过有监督的Hebb学习算法实现其权值的调节,同时通过权系数的在线调整实现自适应控制,提高自适应能力.     

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.