GIS Software for Measuring Space-Time Accessibility in Transportation Planning and Analysis

Transportation systems exist to improve individual accessibility. However, emerging applications of GIS in transportation (GIS-T) and intelligent transportation system (ITS) focus on throughput (the amount of system flow) rather than accessibility. Throughput is related but not equivalent to accessibility. Sensitive transportation planning requires rigorous, realistic and tractable accessibility measures. This paper reports on the development of GIS software that implement space-time accessibility measures (STAMs). The STAMs reflect the benefits that individuals receive from the transportation system. They are easily interpreted, particularly with respect to changes in accessibility. The STAMs also consider the locations and travel velocities dictated by the transportation system as well as individuals daily activity schedules. Tractable computational procedures allow calculation of the STAMs for detailed, urban-scale transportation networks. A prototype ArcInfo^®-linked software system that runs on Windows NT^® or Sun Solaris^® platform implements the STAMs with user-friendly interfaces and project management tools.     

Query Performance Prediction for Information Retrieval Based on Covering Topic Score

We present a statistical method called Covering Topic Score （CTS） to predict query performance for information retrieval. Estimation is based on how well the topic of a user＇s query is covered by documents retrieved from a certain retrieval system. Our approach is conceptually simple and intuitive, and can be easily extended to incorporate features beyond bag- of-words such as phrases and proximity of terms. Experiments demonstrate that CTS significantly correlates with query performance in a variety of TREC test collections, and in particular CTS gains more prediction power benefiting from features of phrases and proximity of terms. We compare CTS with previous state-of-the-art methods for query performance prediction including clarity score and robustness score. Our experimental results show that CTS consistently performs better than, or at least as well as, these other methods. In addition to its high effectiveness, CTS is also shown to have very low computational complexity, meaning that it can be practical for real applications.     

时空数据库变体最近邻查询问题探讨

最近邻查询在地理信息系统、智能交通系统、多媒体应用以及数据挖掘等领域有着广泛的应用,随着对最近邻查询问题研究的深入,其应用前景和发展空间将更为广阔。针对近几年时空数据库中提出的最近邻查询的多种变体查询问题进行了详细地介绍和分析,总结了解决这些变体最近邻查询问题的有效方法,最后对最近邻查询问题的发展方向进行了展望。     

车用自组织网络中数据聚合算法综述

具有短距离通信能力的车载设备的改进和短距离微波通信授权频谱的分配推动了智能交通系统应用的发展,促进了车用自组织网络(VANET)的研究。对于VANET上的应用数据分发是各类应用实现的基础,同时数据聚合又是实现数据分发的关键技术。介绍了VANET的概念和网络构架,给出了当前VANET上的一些典型应用;详细阐述了VANET上的数据分发的基本结构,并对数据聚合算法的研究现状进行了详细的分析和比较;最后总结并展望了VANET上的数据聚合在未来一段时间的研究重点。     

Simulation and evaluation of urban bus-networks using a multiagent approach

Evolution of public road transportation systems requires analysis and planning tools to improve service quality. A wide range of road transportation simulation tools exist with a variety of applications in planning, training and demonstration. However, few simulation models take into account traveler behaviors and vehicle operation specific to public transportation. We present in this paper a bus-network simulation tools which include these specificities and allows to analyze and evaluate a bus-network at diverse space and time scales. We adopt a multiagent approach to describe the global system operation as behaviors of numerous autonomous entities such as buses and travelers.     

车辆自组织网络中新型NP-CSMA随机多址协议研究分析

智能交通的出现使得车辆自组织网络受到越来越多的关注。车辆自组织网络的动态拓扑结构变化非常剧烈,这对网络的吞吐率、传输速率等性能提出了很高的要求。提出1种具有握手机制协议的自适应多通道双时钟NP-CSMA随机多址接入协议。该协议首先区分2种P-CSMA协议,握手机制成功解决了隐藏的终端问题,双时钟机制减少了平均空闲时间,多通道机制增加通道数量和划分用户优先级的同时提高了系统吞吐率,自适应机制能够使系统在高负载下保持稳定吞吐率。还对该协议的传输速率进行了分析,得出该协议的传输速率相对较高的结论。通过平均周期方法推导吞吐率和传输速率的计算公式,仿真结果与理论推导一致。     

无线充电传感器网络能量效率优化研究

本文将SWIPT技术应用到无线充电传感器网络中,提出了一种基于SWIPT的协作传输协议（简称CTS）,利用无线信息和能量的协作传输来提高无线能量传输的效率。在此基础上,设计了一个以最大化网络效用为目的的资源分配策略优化问题,并提出RAPOA算法来求解问题。仿真实验表明CTS最大化了网络效用,提高了无线充电传感器网络的能量传输效率。     

基于Jaguar CTS的企业多层分布式应用架构

文章建立在Jaguar CTS的基础之上,详细研究了一种全新的企业多层分布式应用架构,首先对Jaguar CTS实际应用中的主要优势、以及使用特性进行了简要分析。进而提出了在Jaguar CTS支持下,整个企业多层分布式应用架构的作业流程,对于信息服务需求庞大、数据处理复杂的电力企业而言,此种分布式应用架构有着良好的发展潜力,值得进一步关注与应用。     

基于Jaguar CTS的三层分布式应用的研究

文章介绍了Jaguar CTS的基本概念、主要特点以及利用Jaguar CTS来构建应用系统的方法。通过Jaguar CTS来构建三层分布式应用,可以提高系统的可靠性、灵活性、可伸缩性和可扩展性。     

分布式无线交通监控系统的研究与实现

无线传感器网络是一种全新的信息获取和处理技术。相对于现有交通监控系统中所应用的各种技术，无线传感器网络具有不受环境限制、自组织、分布性等优势。该文提出了基于无线传感器网络的分布式无线交通监控系统的设计方案，详细探讨了构造自组织、自适应的智能交通网络所涉及的车辆速度测试、车辆定位、车流量检测等技术。并指出其对未来交通发展的意义。     

视频技术在智能交通系统中的应用

论述了图像信号处理技术在智能交通系统(ITS)中应用的热点和关键问题。针对智能交通管理系统的多个应用实例，如城市交通智能监控、电子警察系统及流量监测和交通诱导系统等，给出了应用视频技术的解决方案，并与传统的交通管理方式作了对比。     

A Wavelet Neural Network Based Non-linear Model Predictive Controller for a Multi-variable Coupled Tank System

In this paper, a novel real time non-linear model predictive controller(NMPC) for a multi-variable coupled tank system(CTS) is designed. CTSs are highly non-linear and can be found in many industrial process applications. The involvement of multi-input multi-output(MIMO) system makes the design of an effective controller a challenging task. MIMO systems have inherent couplings,interactions in-between the process input-output variables and generally have an complex internal structure. The aim of this paper is to design, simulate, and implement a novel real time constrained NMPC for a multi-variable CTS with the aid of intelligent system techniques. There are two major formidable challenges hindering the success of the implementation of a NMPC strategy in the MIMO case. The first is the difficulty of obtaining a good non-linear model by training a non-convex complex network to avoid being trapped in a local minimum solution. The second is the online real time optimisation(RTO) of the manipulated variable at every sampling time.A novel wavelet neural network(WNN) with high predicting precision and time-frequency localisation characteristic was selected for an MIMO model and a fast stochastic wavelet gradient algorithm was used for initial training of the network. Furthermore, a genetic algorithm was used to obtain the optimised parameters of the WNN as well as the RTO during the NMPC strategy. The proposed strategy performed well in both simulation and real time on an MIMO CTS. The results indicated that WNN provided better trajectory regulation with less mean-squared-error and average control energy compared to an artificial neural network. It is also shown that the WNN is more robust during abnormal operating conditions.     

面向智慧交通的图像处理与边缘计算

随着全球人口的持续增长和城市化进程的加速,道路拥挤、交通事故和污染排放增加等问题日益严重。智慧交通系统旨在借助先进的信息与通信技术建成高效安全、环保舒适的交通与运输体系,提供全方位的交通信息服务和安全高效、经济快捷的交通运输与出行服务。经过各国多年来的竭力推进与发展,智慧交通系统在交通管理、自动驾驶与车路协同等方向均得到广泛的应用。智慧交通的发展离不开通信、计算机与控制等研究方向的突破与创新。其中,图像处理作为智慧交通系统的核心技术之一,它的研究进展直接影响着智慧交通系统的部署。图像处理技术是指计算机对图像进行增强、复原、提取特征、分类和分割等技术处理,通过对交通视觉图像的处理,为智慧交通系统的感知、识别、检测、跟踪和路径规划等功能提供了最直接与重要的信息。此外,面对智慧交通系统所产生的大量数据计算任务,边缘计算技术则将中心云服务下沉至各边缘节点附近,不但能够优化算力负载分配,还能够满足智慧交通应用与服务对低时延、高响应速度的需求。本文从智慧交通系统的发展现状入手,分别围绕面向智慧交通的图像处理与边缘计算技术,阐述其研究热点与前沿进展,汇总与比较国内外的相关学术和产业成果,并对智慧交通系统中的图像处理及边缘计算技术未来的发展进行总结分析与趋势展望。     

嵌入式Linux操作系统实时性的分析与研究

通过分析嵌入式Linux在实时应用中的不足,从软中断模拟技术、可抢占式内核机制和实时调度策略等方面给出了改善系统实时性能的方法,同时提出了宏观调度结构,拓展了实时系统的应用范围。     

物流运输配送Intranet平台设计

随着社会对物流需求的增加以及信息化进程的加快,物流企业的信息化已经成为企业优化服务质量、提高竞争优势的重要手段。而我国目前大多物流企业缺乏一套功能健全的运输配送系统软件,并且没有很好的先例进行借鉴。因此,开发出一套完善的运输配送系统Intranet平台软件,对提高物流企业作业效率,降低作业成本从而实现对企业的信息化管理具有重要意义。针对中国物流企业面临的这一尴尬现状,本文着重了解运输配送系统平台软件运作的基础上,通过开发设计出物流运输配送系统Intranet平台软件以实现对运输配送系统中的运输、配送、出入库、仓储等的有效管理,达到提高有效管理企业资源效率的目的。     

基于PowerDynamo的Web应用技术研究

介绍了PowerDynamo的工作原理,以及在PowerBuilder开发环境中基于PowerDynamo、Jaguar CTS建立Web应用的技术,详细说明了如何使用PowerBuilder创建Web target站点、创建网页及编写脚本。     

An advanced database accelerator

The authors report on a research project launched to develop a complete database management system (DBMS) to support emerging applications. They developed a hardware architecture consisting of a general-purpose host computer and the Delta Driven Computer (DDC), a parallel system that plays the role of a relational database accelerator. They also used compilation and I/O reduction to improve the efficiency of the DBMS and proposed a production-rule language that could be compiled into programs with explicit parallelism. The authors present their research objectives, give a general overview of the DDC, and discuss the elements of a complete DBMS     

城市慢行交通网络数据建模研究

城市慢行交通系统是现代城市交通系统的重要组成部分,随着多模式城市交通发展,建立便捷和高效的城市慢行交通网络系统成为现代城市解决交通问题和提升交通运行效率的关键措施。基于此,文中应用统一建模语言（UML）和地理标识语言（GML）建立城市慢行交通网络数据模型,提出一种统一的和一致性的交通地理要素定义和性质描述方法,并阐述基于GML的城市慢行交通网络的地理要素和关系表达。研究成果促进了城市交通地理数据的组织、表达、集成、共享和操作,对建立高效的城市慢行交通网络系统具有重要的理论价值。     

A fuzzy linguistic model for the prediction of carpal tunnel syndrome risks in an occupational environment

This research presents the development and evaluation of a fuzzy linguistic model designated to predict the risk of carpal tunnel syndrome (CTS) in an occupational setting. CTS has become one of the largest problems facing ergonomists and the medical community because it is developing in epidemic proportions within the occupational environment. In addition, practitioners are interested in identifying accurate methods for evaluating the risk of CTS in an occupational setting. It is hypothesized that many factors impact an individual's likelihood of developing CTS and the eventual development of CTS. This disparity in the occurrence of CTS for workers with similar backgrounds and work activities has confused researchers and has been a stumbling block in the development of a model for widespread use in evaluating the development of CTS. Thus this research is an attempt to develop a method that can be used to predict the likelihood of CTS risk in a variety of environments. The intent is that this model will be applied eventually in an occupational setting, thus model development was focused on a method that provided a usable interface and the desired system inputs can also be obtained without the benefit of a medical practitioner. The methodology involves knowledge acquisition to identify and categorize a holistic set of risk factors that include task-related, personal, and organizational categories. The determination of relative factor importance was accomplished using analytic hierarchy processing (AHP) analysis. Finally a mathematical representation of the CTS risk was accomplished by utilizing fuzzy set theory in order to quantify linguistic input parameters. An evaluation of the model including determination of sensitivity and specificity is conducted and the results of the model indicate that the results are fairly accurate and this method has the potential for widespread use. A significant aspect of this research is the comparison of this technique to other methods for assessing presence of CTS. The results of this evaluation technique are compared with more traditional methods for assessing the presence of CTS.