双B／S模式下解决交通违法视频证据管理的效率问题

对非现场的交通执法,单纯依靠违章照片已不能满足市民、交警和管理者的需要,于是违法视频作为强有力的证据便成为了执法中不可或缺的一部分。通过对在客户端本地构建内嵌服务器和在数据中心搭建应用服务器形成双B／S模式的研究,结合非现场交通执法实践,分析和构建适用于各交巡警部门的交通违法视频管理系统,重点探讨了视频格式的压缩转换、GPFS存储、时间码的嵌入、视频分割、流媒体的播放等。     

分层海洋环境对潜艇腐蚀相关静态电磁信号的影响研究

来源于腐蚀及防腐电流的静态电、磁信号是潜艇水下新的重要的目标特性.为掌握分层海洋环境对其水下分布特征的影响,采用三层平行分层导电媒质模型模拟海洋环境、水平直流电偶极子模拟潜艇腐蚀相关电磁场源,通过数值仿真,研究环境电导率、海洋水深、分层界面等因素对潜艇腐蚀相关静态电场和静态磁场的影响.仿真分析结果表明,分层海洋环境对场有明显影响,且存在普通规律.     

网络舆论暴力的伦理考量

互联网是一把“双刃剑”,它给我们的生活带来便利的同时也引发了不少社会问题。文章分析了近年来频繁出现在网络中的舆论暴力事件的含义及特征,全面探究了其产生的伦理根源,并针对其产生的原因提出了相应的伦理对策。     

In-home power line communication media access control protocol based on collision resolution

Most existing media access control (MAC) protocols in power line communication (PLC) networks just discard the colliding data packets when collision occurs. The collision deteriorates throughput and delay performance of system under high traffic conditions. This article presents a novel media access scheme with fast collision resolution for in-home power line networks. It works by first recognizing the colliding stations through detecting the inserted unique ID sequence ahead of data packets, then the source nodes retransmitting their packets immediately after the collision slot. The proposed protocol maintains the benefits of ALOHA systems. It needs no scheduling overhead and is suitable for bursty sources, such as multimedia data packets. Computer simulations have demonstrated that this approach can achieve high throughput due to its ability of resolving collisions.     

Morning commute in a single-entry traffic corridor with no late arrivals

This paper analyzes a model of early morning traffic congestion, that is a special case of the model considered in Newell (1988). A fixed number of identical vehicles travel along a single-lane road of constant width from a common origin to a common destination, with LWR flow congestion and Greenshields’ Relation. Vehicles have a common work start time, late arrivals are not permitted, and trip cost is linear in travel time and time early. The paper explores traffic dynamics for the social optimum, in which total trip cost is minimized, and for the user optimum, in which no vehicle’s trip cost can be reduced by altering its departure time. Closed-form solutions for the social optimum and quasi-analytic solutions for the user optimum are presented, along with numerical examples, and it is shown that this model includes the bottleneck model (with no late arrivals) as a limit case where the length of the road shrinks to zero.     

A latent class accelerated hazard model of social activity duration

Over the past decade, activity scheduling processes have gained increasing attention in the field of transportation research. However, still little is known about the scheduling of social activities even though these activities account for a large and growing portion of trips. This paper contributes to this knowledge. We analyze how the duration of social activities is influenced by social activity characteristics and characteristics of the relationship between the respondent and the contacted person(s). To that end, a latent class accelerated hazard model is estimated, based on social interaction diary data that was collected in the Netherlands in 2008. Chi-square tests and analyses of variance are used to test for significant relations between the latent classes and personal and household characteristics. Findings suggest that the social activity characteristics and the characteristics of the relationship between the socializing persons are highly significant in explaining social activity duration. This shows that social activities should not be considered as a homogenous set of activities and it underlines the importance of including the social context in travel-behavior models. Moreover, the results indicate that there is a substantial amount of latent heterogeneity across the population. Four latent classes are identified, showing different social activity durations, and different effects for both categories of explanatory variables. Latent class membership can be explained by household composition, socio-economic status (education, income and work hours), car ownership and the number of interactions in 2 days.     

基于物理规律的气垫船气液介质仿真系统研究

针对全垫升气垫船气液介质复杂场景实时再现仿真需求,基于粒子系统原理和OSG渲染平台,考虑气垫船近场波浪高程模型、气垫船垫升系统压力及流量仿真模型以及气垫船气流场特点,提出了一种基于多模型的气垫船航行时气液介质特效仿真框架和实现方法。搭建了该技术的体系结构和实现流程,解决了不同开发环境下建立的异构模型仿真问题,并通过仿真模拟计算验证了该技术的可行性和正确性。仿真结果符合气垫船航行时的气液介质外形特征、作用范围以及气液介质产生的随机性和规律性特征,能快速逼真地实现气垫船航行时气液介质视景特效,对增强气垫船模拟训练效果具有重要的意义。     

网络多媒体与英语写作教学

本文分析了高校传统英语写作教学的现状及问题,并介绍了利用网络多媒体进行英语写作教学的优势,最后探讨了如何有效利用网络多媒体进行英语写作教学及需要注意的问题以提高学生的写作能力。     

Rethinking the links between social exclusion and transport disadvantage through the lens of social capital

This paper provides a critical review of the progress in understanding the linkages between transport disadvantage and social exclusion. It follows earlier work in proposing social capital as a concept that mediates those linkages but argues that transport researchers must not confine themselves to conceptualisations of social capital as predominantly benign and capable of reducing transport disadvantage and social exclusion. A range of hypothetical pathways is discussed, highlighting the Janus-faced character of social capital as a medium for both the effectuation of progressive social change and the perpetuation and creation of social inequalities. An analysis is provided of the extent to which the recent transport-related literature supports or rejects the hypothesised pathways, and key avenues for future research are identified.     

城市中心区拥挤收费系统评价方法

本文介绍了拥挤收费系统的概念,提出了拥挤收费系统的综合评价指标及评价方法.最后设计了中心区拥挤收费方案,对中心区拥挤收费方案进行了评价.