基于排队模型的电动汽车充电桩数量优化设计

通过对电动汽车充电行为的分析,采用顾客带有不耐烦和止步行为的有限容量M/M/C/N排队模型对充电场所充电服务系统进行建模.通过求解模型的平衡方程,获得系统稳态下的队长分布及其它多项性能指标.以系统性能指标为基础,从经济效益与社会效益的角度提出了充电服务系统优化设计的目标函数,并通过数字例子对优化模型进行了说明.分析了模型参数对系统充电桩最优配置数的影响,从中可看出,系统容量、顾客的不耐烦率及顾客的止步概率等参数对充电桩数量的优化设计都会产生不可忽视的影响.     

Impulsive non‐autonomous dynamical systems and impulsive cocycle attractors

In this work, we define the notions of ‘impulsive non‐autonomous dynamical systems’ and ‘impulsive cocycle attractors’. Such notions generalize (we will see that not in the most direct way) the notions of autonomous dynamical systems and impulsive global attractors in the current published literature. We also establish conditions to ensure the existence of an impulsive cocycle attractor for a given impulsive non‐autonomous dynamical system, which are analogous to the continuous case. Moreover, we prove the existence of such attractor for a non‐autonomous 2D Navier–Stokes equation with impulses, using energy estimates. Copyright © 2016 John Wiley & Sons, Ltd.     

Well‐posedness of non‐autonomous linear evolution equations in uniformly convex spaces

This paper addresses the problem of well‐posedness of non‐autonomous linear evolution equations in uniformly convex Banach spaces. We assume that for each t is the generator of a quasi‐contractive, strongly continuous group, where the domain D and the growth exponent are independent of t . Well‐posedness holds provided that is Lipschitz for all . Hölder continuity of degree is not sufficient and the assumption of uniform convexity cannot be dropped.     

On the control problem for a compound wheeled vehicle

A compound transport vehicle with one steerable wheel is considered as a controlled mechanical system with nonholonomic constraints. A control system for this system is synthesized within the framework of the kinematic approximation. A procedure is proposed to synthesize a robust controller for the system. The efficiency of this procedure is demonstrated with an example __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 11, pp. 105–112, November 2007.     

GPS／GLONASS组合接收机自备完善性监测和导航性能研究

本文应用近似径向误差保护判别准则，研究不同数量的卫星发生硬故障条件下，飞机非精密进场或终端航行时，ＧＰＳ／气压高度表组合系统、ＧＰＳ／ＧＬＯＮＡＳＳ／气压高度表组合系统接收机自备完善性监测可用性和导航解的可用性     

桥梁表面不平顺对车-桥耦合振动系统动力效应的影响

利用模态分析法以及时变力学系统的求解方法,考虑桥面不平顺产生的随机激励,以简支梁桥为对象,计算了四自由度模型车辆-桥梁耦合系统的动力效应,讨论了不同等级桥面平整度情况下桥梁冲击系数、车辆垂直加速度、车轮对桥的作用力的变化规律。结果表明,随着不平整度系数逐渐增大,冲击系数逐渐增大;平整度较差等级的桥面,车辆垂直加速度较大,车轮对桥的作用力也较大。     

Dynamics of Geometrically Nonlinear Rods: II. Numerical Methods and Computational Examples

The paper selects and develops appropriate numerical solutionmethods for initial boundary value problems of the equations of motionof geometrically nonlinear extensible Euler–Bernoulli-beams. A finiteelement method that uses first-order Hermitian polynomials as interpolationfunctions for the rod axis position vector is used as discretizationtechnique. An averaging method for the calculation of net forces andmoments is developed that achieves a better approximation than thedirect calculation from the strains. Time integration is done usingan energy and momentum conserving algorithm that is proposed in thispaper and Newmark type methods. The derived algorithms are used tosolve problems from space and marine engineering. The obtained simulationresults are compared with results which have been already publishedin the literature or were calculated by different methods.     

激光水推进技术的实验研究

激光水推进技术是一种新概念的推进技术,其原理是以水作为推进工质,通过强激光辐照后水的爆炸、反喷进行驱动,具有很高的冲量耦合系数Cm。本文介绍了以硬铝LY12、黄铜、45号钢和石墨作为基板,通过改变基板表面蓄水槽的深度(0mm,3mm,5mm)进行了较系统的激光水推进实验,研究了不同材质基板和不同水槽深度对推进效能的影响,结果表明,蓄水槽深度为3mm的铝基板的Cm最高,达到了350dyne/w,比直接烧蚀提高了2个量级。通过分析实验数据还初步总结出:推进过程中,基板喷射产物颗粒越细,水推进的Cm就越大;对于金属基板,Cm随板材原子量的增加而减小。     

潜射导弹出水过程响应分析

水下点火发射的导弹出水运行过程中与反馈的流体形成相互作用的流固耦合问题。 工程方法计算导弹的附连水质量，从而得到了考虑汉固耦合影响以后的导弹出水的自振特性及动力响应结果。     

Ergodic Properties of Weak Asymptotic Pseudotrajectories for Semiflows

It is known that various deterministic and stochastic processes such as asymptotically autonomous differential equations or stochastic approximation processes can be analyzed by relating them to an appropriately chosen semiflow. Here, we introduce the notion of a stochastic process X being a weak asymptotic pseudotrajectory for a semiflow and are interested in the limiting behavior of the empirical measures of X. The main results are as follows: (1) the weak* limit points of the empirical measures for X axe almost surely -invariant measures; (2) given any semiflow , there exists a weak asymptotic pseudotrajectory X of such that the set of weak* limit points of its empirical measures almost surely equal the set of all ergodic measures for ; and (3) if X is an asymptotic pseudotrajectory for a semiflow , then conditions on that ensure convergence of the empirical measures are derived.