用Matlab实现减摇鳍模糊控制器仿真

基于Conolly理论建立了船舶模型,以横摇角和横摇角速度为输入量,鳍角为输出量,应用模糊控制理论设计了减摇鳍模糊控制器;利用Matlab的fuzzylogic工具箱针对不同海情对控制器进行了仿真.结果表明,减摇鳍模糊控制器与传统PID控制器相比具有更好的控制效果.     

自适应模糊滑模在火箭炮位置伺服系统中的应用

针对多管火箭炮交流位置伺服系统转动惯量和负载力矩变化大的特性,设计了自适应模糊滑模位置控制器.用模糊控制逼近理想滑模控制,设计切换控制补偿逼近误差,自适应控制调节模糊参数和切换控制的不确定上界.为了保证系统渐进稳定和可控,根据李亚普函数导出自适应率.仿真结果表明该控制策略不仅保证了系统的静、动态特性,而且对负载扰动和系统参数摄动具有较强的鲁棒性.     

陕西蒲城Q_2黄土物质组成试验研究

利用激光散射粒度分布分析仪、X射线衍射仪等先进的测试手段和化学成分分析,得到了陕西蒲城Q2黄土的物质组成特点,包括颗粒组成、矿物成分、化学成分、易溶盐含量、酸碱特性等,并指出与Q3黄土的差异。为深入研究Q2黄土的湿陷机理和工程地质特性以及解释与Q3黄土工程性质的差异提供科学依据。     

Bounding the optimal burn‐in time for a system with two types of failure

Burn‐in is a widely used method to improve the quality of products or systems after they have been produced. In this paper, we consider the problem of determining bounds to the optimal burn‐in time and optimal replacement policy maximizing the steady state availability of a repairable system. It is assumed that two types of system failures may occur: One is Type I failure (minor failure), which can be removed by a minimal repair, and the other is Type II failure (catastrophic failure), which can be removed only by a complete repair. Assuming that the underlying lifetime distribution of the system has a bathtub‐shaped failure rate function, upper and lower bounds for the optimal burn‐in time are provided. Furthermore, some other applications of optimal burn‐in are also considered. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Hypersonic impact flash characteristics of a long-rod projectile collision with a thin plate target

Impact flash occurs when objects collide at supersonic speeds and can be used for real-time damage assessment when weapons rely on kinetic energy to destroy targets.However,the mechanism of impact flash remains unclear.A series of impact flash experiments of flat-head long-rod projectiles impacting thin target plates were performed with a two-stage light gas gun.The impact flash spectra for 6061 aluminum at 1.3-3.2 km/s collision speeds were recorded with a high-speed camera,a photoelectric sensor,and a time-resolved spectrometer.The intensity of the impact flash exhibited a pulse charac-teristic with time.The intensity(I)increased with impact velocity(V0)according to I∝Vn0,where n = 4.41 for V0 ＞ 2 km/s.However,for V0 ＜ 2 km/s,n = 2.21,and the intense flash duration is an order of magnitude less than that of higher V0.When V0 ＞ 2 km/s,a continuous spectrum(thermal radiation background)was observed and increased in intensity with V0.However,for V0 ＜ 2 km/s,only atomic line spectra were detected.There was no aluminum spectral lines for V0 ＜ 2 km/s,which indicated that it had not been vaporized.The initial intense flash was emission from excited and ionized ambient gases near the impact surface,and had little relationship with shock temperature rise,indicating a new mechanism of impact flash.     

舰载烟幕弹的最佳使用时机

针对激光制导反舰导弹的作战使用过程 ,依据侦察探测的倒立方律及对导弹的捕捉概率 ,探讨舰载烟幕弹的最佳使用时机问题 ,指出应充分利用舰艇 C3I系统的综合信息 ,由舰指挥员负责实施     

对房地产策划的理性思考

随着房地产业的迅速发展,房地产策划在观念、专业化、组织、创新、协作和信息等方面存在着一些与发展不和谐的因素,通过对房地产策划的危机进行理性思考,以寻找战胜危机的可靠途径。在全面分析房地产策划危机的基础上,从贯穿市场意识、主动创造效益、强化整合功能、塑造品牌、引进管理等方面寻找形成房地产策划核心竞争力的源泉,以战胜暂时的危机。其结果证明了房地产策划仍然具有强大的生命力,暂时的危机一定能被克服。     

基于遗传算法的通信网络可靠性优化设计

在可靠性条件约束下 ,使网络成本最低是网络规划NP hard问题 .文章提出一种基于遗传算法的优化方法解决了这类问题 .仿真结果表明这种算法是有效的 .     

基于XML的装备维修信息标准化

基于XML的装备维修信息标准化是我军装备信息保障的发展趋势.以设备技术说明书为例,对其进行了标准化信息分解,构建了相应的DTD和数据库结构,并讨论了实现标准化维修信息动态传输与交换的相关问题.     

Mathematical formulation and heuristic algorithm for the block relocation and loading problem

This study considers the block relocation and loading problem in container terminals. The optimal loading sequence and relocation location are simultaneously decided on the basis of the desired ship‐bay and initial yard space configuration. An integer linear programming model is developed to minimize the number of relocations in the yard space on the basis of no shifts in the ship bay. The accuracy of the model is tested on small‐scale scenarios by using CPLEX. Considering the problem size in the real world, we present a rule‐based heuristic method that is combined with a mathematical model for the removal, loading, and relocation operations. The influence of rules on algorithm performance is also analyzed, and the heuristic algorithm is compared with different types of algorithms in the literature. The extensive numerical experiments show the efficiency of the proposed heuristic algorithm.