Platoon based cooperative driving model with consideration of realistic inter-vehicle communication

Recent developments of information and communication technologies (ICT) have enabled vehicles to timely communicate with each other through wireless technologies, which will form future (intelligent) traffic systems (ITS) consisting of so-called connected vehicles. Cooperative driving with the connected vehicles is regarded as a promising driving pattern to significantly improve transportation efficiency and traffic safety. Nevertheless, unreliable vehicular communications also introduce packet loss and transmission delay when vehicular kinetic information or control commands are disseminated among vehicles, which brings more challenges in the system modeling and optimization. Currently, no data has been yet available for the calibration and validation of a model for ITS, and most research has been only conducted for a theoretical point of view. Along this line, this paper focuses on the (theoretical) development of a more general (microscopic) traffic model which enables the cooperative driving behavior via a so-called inter-vehicle communication (IVC). To this end, we design a consensus-based controller for the cooperative driving system (CDS) considering (intelligent) traffic flow that consists of many platoons moving together. More specifically, the IEEE 802.11p, the de facto vehicular networking standard required to support ITS applications, is selected as the IVC protocols of the CDS, in order to investigate how the vehicular communications affect the features of intelligent traffic flow. This study essentially explores the relationship between IVC and cooperative driving, which can be exploited as the reference for the CDS optimization and design.     

Port system evolution – the emergence of second-tier hubs

Some evidence has emerged of second-tier hubs inserting themselves between hubs and feeder ports, producing a new hierarchy of port networks. This article aims to establish the dynamics of this process based on illustrative cases in Asia, South America, and Europe. Findings reveal spatial factors to include a cluster of small ports with minimal sailing distance within a given range, suitable channel and berth depth, and ideally high capacity inland links. From the economic perspective, demand-side factors include a local captive market and aggregated demand to be captured from other ports, while supply-side factors include diseconomies of scale at traditional hubs, an increase in direct services, an increase in large feeder vessels calling from first-tier hubs which are then transhipped to smaller feeders for serving local ports, and an increase in overland servicing of local smaller ports. From a strategic perspective, vertical and horizontal integration in the shipping sector has produced extensive network economies, whereby shipping lines look to create group-specific port hierarchies, enhanced in the presence of aggressive management strategies and supportive policies. This finding suggests that proactive port stakeholders can in certain circumstances seize the opportunity to capture this role within their port range.     

国际干散货运输市场的非“完全竞争”

本文主要以经济学上完全竞争的四个基本假定为主线,从国际干散货运输市场已不能完全符合这4个假定来论述国际干散货运输市场的非“完全竞争”。     

价格竞争在我国航运市场的运用及影响

通过对价格竞争在我国航运市场的运用、成因和影响的分析,反映出我国航运市场竞争情况的一些规律,并对航运业的发展提出了有益的建议。     

极阳进化律

在生物的漫长进化过程中,不同阴阳率的物种或(个体)其命运迥然不同,生存环境的压力包括常规环境胁迫和灾难,使得极阳物种(或个体)在生存竞争中获胜,较之其他物种或个体表现出适应优势.极阳进化律认为,生物类群分化的极阳者是进化的领头羊,引领着进化的总趋势.本文系统介绍了极阳进化律的内容,并讨论其对我们人类社会发展规律的意义.     

打破"诸侯经济"创双赢

上海建设国际航运中心,确定了洋山深水港的建设项目,由此带来了上海港和宁波港激烈的货源之争,而更大的竞争压力来自釜山等东北亚大型港口。面对这样的形势,上海、宁波两港应积极合作,一致对外,争取早日把上海港建成国际航运中心,同时使宁波港得到迅速发展。当“错位发展”的合作形式遇到困难时,以资本为纽带的“港口联盟”可能会是一种好的合作形式。     

油船市场现状与策略

分析了油船市场的现状,明确指出国有油船运输缺口很大。认为目前我国已具备了发展油船船队的实力,提出了应采取的竞争策略,以适应国家经济建设和参与国际化市场竞争的需要。     

开放式智能安全代理体系架构设计

针对目前网络安全产品、技术和安全模型存在的问题，提出一种具有开放体系架构的通用智能安全代理模型。智能安全代理由插件运行管理平台和一组插件构成。插件平台包括消息解释器、路由器、黄页及黑板等组件，负责监视和管理插件的运行。利用注册／注销，代理通信、协作与委托计算机制，多个智能安全代理可以组成一个代理社区，实现分布式异构网络环境下的协同安全防御。实践表明，该模型具有良好的开放性、通用性、多功能性，以及可伸缩、可移值、智能化和面向应用等特性，可以为各类终端节点提供多种安全保护。     

科技型企业实施对外开放战略的几点思考

全球化的加速发展使我国科技型企业实施对外开放战略面临更多的机遇和挑战。现着重从"引进来"和"走出去"两方面,探讨科技型企业的对外开放战略。在参与国际合作和竞争中,科技型企业应立足自主创新,完善制度保障,增强自身实力,并着眼互利共赢,在利用外资和对外投资的实践中拓宽发展空间。     

关于成本管理成为公司核心竞争力的几点思考

该文强调加强建设工程成本管理,是公司打造其核心竞争力的途径之一。文章主要结合企业绩效管理发展理论,对成本管理成为公司核心竞争力提出了几点思考。