基于复杂排队系统的三值光学计算机服务模型与性能分析

三值光学计算机的运算请求处理过程缺乏合理、系统的性能评价标准与体系。基于M/M/1、M/M/n、M~X/M/1和M/M~B/1构成的复杂排队系统,构建三值光学计算机的四阶段服务模型,同时建立立即调度和结束时调度两种策略和算法。基于不同排队系统讨论运算请求的接收时间、预处理时间、运算时间和发送时间的计算方法,进而得到最终响应时间。通过仿真实验对两种策略的模型进行验证,结果表明,结束时调度策略明显优于立即调度策略。     

Driving force coordinated control of an 8 ×8 in-wheel motor drive vehicle with tire-road friction coefficient identification

Because of the complexities of tire-road interaction,the wheels of a multi-wheel distributed electric drive vehicle can easily slip under certain working conditions.As wheel slip affects the dynamic per-formance and stability of the vehicle,it is crucial to control it and coordinate the driving force.With this aim,this paper presents a driving force coordination control strategy with road identification for eight-wheeled electric vehicles equipped with an in-wheel motor for each wheel.In the proposed control strategy,the road identification module estimates tire-road forces using an unscented Kalman filter al-gorithm and recognizes the road adhesion coefficient by employing the recursive least-square method.According to road identification,the optimal slip ratio under the current driving condition is obtained,and a controller based on sliding mode control with a conditional integrator uses this value for accel-eration slip regulation.The anti-slip controller obtains the adjusting torque,which is integrated with the driver-command-based feedforward control torque to implement driving force coordination control.The results of hardware-in-loop simulation show that this control strategy can accurately estimate tire-road forces as well as the friction coefficient,and thus,can effectively fulfill the purpose of driving force coordinated control under different driving conditions.     

Optimization of process parameters of the activated tungsten inert gas welding for aspect ratio of UNS S32205 duplex stainless steel welds

The activated TIG (ATIG) welding process mainly focuses on increasing the depth of penetration and the reduction in the width of weld bead has not been paid much attention. The shape of a weld in terms of its width-to-depth ratio known as aspect ratio has a marked influence on its solidification cracking tendency. The major influencing ATIG welding parameters, such as electrode gap, travel speed, current and voltage, that aid in controlling the aspect ratio of DSS joints, must be optimized to obtain desirable aspect ratio for DSS joints. Hence in this study, the above parameters of ATIG welding for aspect ratio of ASTM/UNS S32205 DSS welds are optimized by using Taguchi orthogonal array (OA) experimental design and other statistical tools such as Analysis of Variance (ANOVA) and Pooled ANOVA techniques. The optimum process parameters are found to be 1 mm electrode gap, 130 mm/min travel speed, 140 A current and 12 V voltage. The aspect ratio and the ferrite content for the DSS joints fabricated using the optimized ATIG parameters are found to be well within the acceptable range and there is no macroscopically evident solidification cracking.     

一种鱼雷自导信号频率检测方法研究

靶场在进行智能鱼雷鉴定试验任务时,实时准确地检测出鱼雷自导信号的频率成分是靶标信号处理中的重要环节,谱线比值法便是靶标进行信号处理时检测信号频率的一种有效方法。本文介绍了谱线比值法的基本原理,针对目前鱼雷自导信号特点,对该方法提出了改进方案并进行了仿真。仿真结果表明,经改进的谱线比值法能够满足靶标检测复杂鱼雷自导信号体制下信号频率的使用要求。     

大型商业综合体内影院消防设计探讨

重点介绍了某大型商业综合体内影院的消防设计方案,并进行烟气流动和人员疏散的数值模拟分析,得出该影院消防设计是安全可行的.为确保此类影院的消防安全,建议其疏散楼梯设计不受商场营业与否的影响,且应定期维护保养消防系统.     

数值模拟气/气喷嘴速度比对燃烧性能的影响

为研究应用于全流量补燃循环发动机的不同气/气喷嘴得到的燃烧流场,通过求解NavierStokes方程组,对不同燃料与氧化剂速度比下的流动燃烧过程进行了数值计算,计算结果与实验结果吻合。仿真结果表明:增加速度比能使燃烧火焰面提前,燃烧效率变大。如果发动机的长度受到限制,可以适当增加速度比以实现高效燃烧。     

复杂网络在作战建模中的应用研究

针对作战网络研究中的热点,以复杂网络在作战建模中的应用为主线对取得的研究成果进行了梳理,重点讨论了作战网络的基本拓扑模型、作战网络的抗毁性模型和作战过程的动态网络模型等,指出了作战网络研究中存在的问题以及未来值得进一步探讨的研究方向。     

基于复杂网络的维修保障力量体系建模方法

针对传统的层级式维修保障力量体系在维修保障过程中暴露出的缺陷,从维修保障力量体系与复杂网络的相似性角度出发,提出用复杂网络理论来研究维修保障力量体系。在对维修保障力量活动过程进行网络化抽象的基础上,建立了维修保障力量网络的拓扑模型,提出了描述维修保障力量网络的特征量。以师维修保障力量体系作为研究对象建立了网络拓扑模型,并对该网络结构作了适当改进。通过一系列对比发现改进后的网络更有利于维修保障,这为维修保障力量体系建设提供了一种新思路和新方法。     

The political economy of drones

This paper provides a political economy analysis of the evolution of unmanned aerial vehicles (UAV), or ‘drones’ in the USA. Focus is placed on the interplay between the polity and private economic influences, and their impact on the trajectory of political, economic, and military outcomes. We identify the initial formation of the drone industry, trace how the initial relationships between the military and the private sector expanded over time, and discuss present relationships. Understanding the historical evolution of UAV technology, as well as the major players in the industry today, is important for ongoing policy debates regarding the use of drones both domestically and internationally.     

基于复杂网络理论的作战系统结构拓扑模型研究

基于复杂网络理论,分析了信息化作战系统网络结构,构建了传统作战系统和信息化作战系统拓扑模型的生成算法,并通过对传统作战系统和信息化作战系统结构拓扑模型度量性质的比较,说明了信息化战争下的作战系统结构特点,为进一步研究网络化战争提供了良好的模型基础．