城市轨道交通移动闭塞列控系统列车追踪间隔研究

目前,基于通信的移动闭塞列控系统作为轨道交通列控系统的主要发展方向,在一定程度上缩短了列车之间的追踪间隔。追踪间隔的计算是列车生成移动授权的前提。列控系统中移动授权的发布由区域控制器来完成。列控系统中由于追踪模式的不同,列车追踪间隔也会有差异,从而影响移动授权生成,影响行车效率。分析了列车移动授权生成原理,研究了列车区间追踪场景下绝对追踪模式和相对追踪模式下的列车追踪间隔,并进行了仿真。仿真分析结果表明:相对追踪模式下列车生成的移动授权更大,可以进一步缩小列车追踪间隔;绝对追踪模式存在最优追踪速度。     

采用COM组件计算铁路货物运价里程的设计方案

介绍用COM组件计算铁路货物运价里程的设计方案,分析货物运价里程对象的数据结构,最短路径算法及其在运价里程计算中的具体实现,COM组件的主要技术参数和运行条件.     

阵列式高射频武器效力仿真分析

针对反舰导弹的运动特性,进行了三维的仿真分析,并研究了反舰导弹的超音速和强机动给目标预测带来不可避免的误差的情况。重点介绍了拦阻射击的概率密度函数公式,通过仿真分析得出结论,在目标预测误差存在而且并不是很小时,拦阻射击比跟踪集火射击在命中率方面有很大的提升。在此基础上,对阵列式高射频武器的结构设计做了初步探讨。     

城市轨道交通客运服务人员智能监测与管理系统设计

为提高客运服务人员智能化监测与管理水平,文章基于超宽带定位和健康监测技术,设计面向城市轨道交通客运服务人员的智能监测与管理系统。从系统架构设计角度出发,对系统的总体架构、逻辑架构、业务功能架构等方面进行详细阐述,并从系统实现角度出发,提出定位基站和系统软硬件部署方案,实现对客运服务人员的定位、轨迹追踪、健康状态监测和应急调度管理等功能,为提高车站运营管理效率和应急指挥调度能力提供基础支撑。     

The use of operational modal analysis and mode tracking for insight into polar vessel operations

Accurate dynamic models of flexible ship structures are required to predict structural vibration caused by environmental loads. Knowledge of dynamic or modal properties are important, for example, to study fatigue damage. In this paper, operational modal analysis (OMA) is used to identify the vibration characteristics of a polar vessel from full-scale acceleration measurements. Five modes are tracked over a range of different operating and environmental conditions, including calm, open water, two ice cases and an open water storm. Compared to the calm, open water conditions, vertical bending modes were generally affected the most by the operating environment, with natural frequency and damping increasing up to 3.7 and 349 %, respectively, in ice. Severity of two-node and three-node vertical bending responses, quantified using a root-mean-square value, were found to be especially large during the open water storm case. Temporal behaviour of two-node and three-node vertical bending due to wave-slamming further contained multiple whipping responses, pointing towards possible cumulative damage over a large number of stress cycles occurring at the midship. Higher damping in ice resulted in responses with lower magnitudes and shorter durations.     

Development of an integrated system based vehicle tracking algorithm with shadow removal and occlusion handling methods

Video image processing system (VIPS) is more efficient than other detecting systems. However, VIPS involves outdoor images and is very sensitive to the external environment, which could greatly decrease its accuracy according to rapid environmental changes. To obtain accurate traffic data accordingly, VIPS must address the problems such as growing shadows in transition; distortion of images due to the headlights at night; noises caused by the rain, snow or fog; and occlusions. This study intends to accurately calculate traffic data while addressing the shadow and occlusion problems, which are the most difficult tasks for the image‐detector‐based traffic data system. In this study, an algorithm for the individual vehicle tracking collection was developed to address the occlusion problem and to eliminate the noises or shadows caused by external environmental factors. A traffic data collection system was also proposed in order to accurately track individual vehicles that pass through the detection region. In addition, establishing an integrated system with shadow removal and occlusion handling using an image processing was also proposed. Copyright © 2010 John Wiley & Sons, Ltd.     

On uniqueness and proportionality in multi-class equilibrium assignment

Over the past few years, much attention has been paid to computing flows for multi-class network equilibrium models that exhibit uniqueness of the class flows and proportionality (Bar-Gera et al., 2012). Several new algorithms have been developed such as bush based methods of Bar-Gera (2002), Dial (2006), and Gentile (2012) that are able to obtain very fine solutions of network equilibrium models. These solutions can be post processed (Bar-Gera, 2006) in order to ensure proportionality and class uniqueness of the flows. Recently developed, the TAPAS, algorithm (Bar Gera, 2010) is able to produce solutions that have proportionality embedded, without requiring post processing. It was generally accepted that these methods for solving UE traffic assignment are the only way to obtain unique path and class link flows. The purpose of this paper is to show that the linear approximation method and some of its variants satisfy these conditions as well. In addition, some analytical results regarding the relation between steps of the linear approximation algorithm and the path flows entropy are presented.     

基于MSP430单片机的太阳能发电装置设计

太阳能作为清洁能源得到了人们广泛的认同,然而,能够随心所欲利用太阳能,并将其作为不同需求的电能输出,还是一个新的课题。本文基于MSP430单片机设计制作了一套太阳能自动跟踪发电装置。为便于携带,确定了装置整体结构可拆卸方案;同时,进行了跟踪算法的设计;选用了大容量铅酸蓄电池以及多通道的USB可调电压输出接口(DC:0-12V),极大方便了当前家庭数码产品的使用及其他应用。装置通过使用,验证了设计的实用性。     

Distributed computing approaches for large‐scale probit‐based stochastic user equilibrium problems

Applications of probit‐based stochastic user equilibrium (SUE) principle on large‐scale networks have been largely limited because of the overwhelming computational burden in solving its stochastic network loading problem. A two‐stage Monte Carlo simulation method is recognized to have satisfactory accuracy level when solving this stochastic network loading. This paper thus works on the acceleration of the Monte Carlo simulation method via using distributed computing system. Three distributed computing approaches are then adopted on the workload partition of the Monte Carlo simulation method. Wherein, the first approach allocates each processor in the distributed computing system to solve each trial of the simulation in parallel and in turns, and the second approach assigns all the processors to solve the shortest‐path problems in one trial of the Monte Carlo simulation concurrently. The third approach is a combination of the first two, wherein both different trials of the Monte Carlo simulation as well as the shortest path problems in one trial are solved simultaneously. Performances of the three approaches are comprehensively tested by the Sioux‐Falls network and then a randomly generated network example. It shows that computational time for the probit‐based SUE problem can be largely reduced by any of these three approaches, and the first approach is found out to be superior to the other two. The first approach is then selected to calculate the probit‐based SUE problem on a large‐scale network example. Copyright © 2011 John Wiley & Sons, Ltd.