基于巡逻历史与道路优先级的武警巡逻策略

针对武警巡逻车辆配置问题,引入了Dijkstra最短路径算法、K—means聚类算法以及计算几何的相关理论,建立了一套警车巡逻模型,并提出了评价巡逻效果的量化评价标准。采用Dijkstra与K—means算法解决了静态警车配置问题;针对警车动态巡逻方案的设计,提出了基于巡逻历史与道路优先级的道路概率选择算法,并给出了不同情况下的警车配置以及巡逻方案。通过MATLAB仿真实验,证明了算法及模型的先进性和实用性。     

基于变结构方法的空空导弹鲁棒逆控制律设计

为克服动态逆控制严重依赖被控对象精确数学模型且鲁棒性较差的缺点,将动态逆与变结构方法相结合采用双环结构设计了空空导弹鲁棒动态逆控制律.将导弹飞行状态划分成快慢2个回路,慢回路(外环)采用变结构控制,并设计扩张状态观测器,对外环中的不确定性进行估计;快回路(内环)采用动态逆控制.仿真结果表明,所设计的控制律具有较好的动态特性和鲁棒性能.     

测试投稿，大家不要管哈~

采用非定常双时间步长方法、刚性旋转动网格技术,结合空间隐式格式数值分析了高超声速钝锥体定常与非定常流场特征,并运用最小二乘法辨识出钝锥体的俯仰阻尼导数。通过与相应的实验数据、工程估算值进行比较,分析并验证了壁面网格雷诺数、钝头比、攻角与质心位置对钝锥体俯仰阻尼导数的影响。同时采用五种差分格式,其中包含五阶精度WENO与高精度WNND格式,对钝锥体俯仰阻尼导数进行了计算,结果表明不同无粘差分格式对俯仰静导数影响较小,但不同格式之间俯仰动导数结果存在差异,分析认为差分格式之间不同的粘性分辨率应是差异的主要来源。     

Formation of adiabatic shearing band for high-strength Ti-5553 alloy: A dramatic thermoplastic microstructural evolution

By using split Hopkinson pressure bar, optical microscopy and electronic microscopy, we investigate the influence of initial microstructures on the adiabatic shear behavior of high-strength Ti–5Al–5V–5Mo–3Cr (Ti-5553) alloy with lamellar microstructure and bimodal microstructure. Lamellar alloy tends to form adiabatic shearing band (ASB) at low compression strain, while bimodal alloy is considerably ASB-resistant. Comparing with the initial microstructure of Ti-5553 alloy, we find that the microstructure of the ASB changes dramatically. Adiabatic shear of lamellar Ti-5553 alloy not only results in the formation of recrystallized β nano-grains within the ASB, but also leads to the chemical redistribution of the alloying elements such as Al, V, Cr and Mo. As a result, the alloying elements distribute evenly in the ASB. In contrast, the dramatic adiabatic shear of bimodal alloy might give rise to the complete lamination of the globular primary α grain and the equiaxial prior β grain, which is accompanied by the dynamic recrystallization of α lamellae and β lamellae. As a result, ASB of bimodal alloy is composed of α/β nano-multilayers. Chemical redistribution does not occur in ASB of bimodal alloy. Bimodal Ti-5553 alloy should be a promising candidate for high performance armors with high mass efficiency due to the processes high dynamic flow stress and excellent ASB-resistance.     

新型舰炮武器系统的自动检测系统

阐述了某新型舰炮武器系统应用仿真技术、控制技术、网络技术和信息处理技术实现自动检测,以及自动检测系统的组成和工作原理。用内模拟仿真驱动技术,实现了舰炮武器系统全自动工作方式下的点迹提取、航迹建立、目标识别、威胁判断、目标指示、捕获跟踪、求解射击诸元,全系统动态联动精度在线评估,以及在线实时故障检测。为海军新装备的操作、使用和维护提供了有效的技术手段。将提高系统可维性和生命力。     

基于DIFHA算子的动态直觉模糊多属性群决策方法

动态决策问题是现实中的一类常见问题。在提出动态直觉模糊混合平均(D IFHA)算子的基础之上,提供一种动态直觉模糊多属性群决策方法。该方法能同时考虑决策过程的阶段性和属性值位置对决策结果的影响,并较好地处理决策过程中的定性指标。分析和算例证实该方法的可行性和实用性。     

衰减荷载作用下饱和软土的固结分析

研究了衰减荷栽作用下软土一维固结问题,建立了小变形固结模型,探讨了荷载衰减规律,分别求解了相应的小变形和大变形固结边值问题;通过理论解答与6块场地实测沉降的比较,表明用考虑荷载衰减的大变形固结理论计算软土一维固结的沉降值与实测结果接近。     

射频识别系统的多目标识别-反碰撞算法

对多目标识别技术的二进制搜索算法、时隙ALOHA算法进行了剖析,并对ALOHA算法用概率论和数理统计的方法进行了深入的理论分析,得出要根据所设计的射频识别系统的特点合理采用各种算法方可得到良好的效果.该算法的实现对提高高速公路上自动收费系统、人员和物流管理等各领域的工作效率具有一定的指导意义.     

导弹结构热防护一体化设计与优化

针对导弹面临的严酷气动热力环境,基于传统波纹夹芯结构,为导弹设计了一种兼具承载和热防护功能的一体化结构。建立热-结构耦合计算模型,对一体化结构进行结构承载与热防护性能分析,结果表明:一体化结构在高温下具有较好的承载能力;增加一体化结构隔热层与内壁厚度有助于提高导弹的热防护效率。以一体化结构热防护效率最高和质量最小为目标,采用第二代非支配排序遗传算法实现了多目标优化,并认识到:一体化结构热防护效率与质量相互影响,设计时需要需综合考虑。     

Application of Markov renewal theory and semi-Markov decision processes in maintenance modeling and optimization of multi-unit systems

In this paper, a condition-based maintenance model for a multi-unit production system is proposed and analyzed using Markov renewal theory. The units of the system are subject to gradual deterioration, and the gradual deterioration process of each unit is described by a three-state continuous time homogeneous Markov chain with two working states and a failure state. The production rate of the system is influenced by the deterioration process and the demand is constant. The states of the units are observable through regular inspections and the decision to perform maintenance depends on the number of units in each state. The objective is to obtain the steady-state characteristics and the formula for the long-run average cost for the controlled system. The optimal policy is obtained using a dynamic programming algorithm. The result is validated using a semi-Markov decision process formulation and the policy iteration algorithm. Moreover, an analytical expression is obtained for the calculation of the mean time to initiate maintenance using the first passage time theory.