中国城镇家庭乘用车物质代谢分析

近20年来,中国私人汽车经历了从无到有的阶段,其引起的物质存量的代谢格局无疑具有重要意义。本文采用自下而上的代谢分析方法,对中国1997—2016年城镇家庭乘用车消费的材料存量进行了动态分析,量化了家庭乘用车消费引起的材料代谢结构与格局。研究结果表明：家庭乘用车消费的物质存量快速增加,2016年城镇家庭乘用车消费户均物质存量已达466.62 kg,比1997年的2.29 kg增长了200多倍。乘用车物质代谢仍处于存量净增加阶段,2016年户均输入量是输出量的9倍以上。同时,存量的材料组成也在不断变化,普通钢材和铁的比例分别由1997年的46.72%和11.79%下降到2016年的37.96%和6.80%,逐渐被高强钢和铝金属替代。虽然目前材料输出还是以普通钢铁为主,但是随着存量的逐渐报废,高强钢和铝等材料会成为报废资源的重要组成,其资源的回收管理值得关注。由于汽车报废的滞后性,高强钢和铝材料等资源大量输出不可避免,这为汽车报废拆解行业资源管理和回收提供了新的方向。     

货运代理企业的发展模式探究

随着全球一体化和中国"入世",国际货运代理企业也加速了在中国的扩张。与之相比,国内的国企货运代理企业和私营货运代理企业有它们的优劣势。阐述各类货运代理企业的特点并探讨了未来的发展模式。     

中国乘用车物质代谢与碳减排策略

中国是全球最大的汽车制造和消费国,汽车行业带来的资源消耗和温室气体排放受到了学者的广泛关注.辨析汽车行业的物质资源代谢特征和碳减排潜力可为落实循环经济政策和实现可持续发展提供科学依据.本文基于动态物质流模型,预测了中国乘用车中21种物质材料的代谢特征,评估了乘用车使用过程中的碳减排潜力.研究结果表明:①1949-201...     

基于经验模态分解的中国出口集装箱运价指数波动特性

中国出口集装箱运价指数（CCFI）能有效反映集装箱海运市场变化,是航运企业经营决策、政府部门航运产业政策制定的重要参考。本文基于经验模态分解（EMD）方法数据驱动的特征及处理非线性、非平稳、多尺度数据序列的优势,将CCFI有效分解为若干本征模态（IMFs）;然后提出综合考虑各IMFs的T检验P值和波动频率对IMFs进行重构,并基于希尔伯特变换和统计分析探讨了各重构项经济内涵;最后从内在影响因素角度探讨了CCFI长期发展趋势、重大事件影响、季节波动、短期市场不均衡的波动特性。研究表明：CCFI长期呈缓慢下降趋势,由市场船舶运力供给大于货运需求决定;CCFI的暴涨暴跌由金融危机等重大事件引起,影响程度大,持续时间长;CCFI的季节波动受季节性生产等因素影响,呈较规则正弦波动,高峰在9、10月份前后,低谷在3、4月份左右;CCFI短期市场不均衡波动受油价、汇率等因素影响,影响程度小,持续时间短;CCFI波动存在约4年的大周期、1年的小周期。     

基于JSP和JavaBean技术的网上书店设计与实现

基于JSP技术和JavaBean技术的有效结合，解决了网上书店系统实现中遇到的数据库连接、数据库访问的汉字处理、书籍的模糊查询、购物车操作等相关技术问题；设计并实现的网上书店系统，具有完备的前、后台处理功能，能满足网上书店的诸多业务需求，对其它电子商务软件的开发具有一定的理论意义和实际应用价值。     

What has the Trolley Dilemma ever done for us (and what will it do in the future)? On some recent debates about the ethics of self-driving cars

Self-driving cars currently face a lot of technological problems that need to be solved before the cars can be widely used. However, they also face ethical problems, among which the question of crash-optimization algorithms is most prominently discussed. Reviewing current debates about whether we should use the ethics of the Trolley Dilemma as a guide towards designing self-driving cars will provide us with insights about what exactly ethical research does. It will result in the view that although we need the ethics of the Trolley Dilemma as important input for self-driving cars, the route towards simply implementing it into automated cars is blocked.     

济南市主城区私家车日常出行碳排放特征及影响因素

私家车出行方式对城市交通碳排放的影响巨大,如何促使居民出行行为的转变是城市实现绿色交通和低碳发展的关键问题。基于济南市主城区居民日常出行的调查数据,本文分析了私家车日常出行碳排放的基本特征,并应用Heckman两步估计法计量模型,研究了私家车碳排放的影响因素,结果发现：①私家车日常出行年碳排放量的平均值为2.22t,空间分布呈现中心低、外围高的差异化格局,个体分布则符合60/20的量化分布;②与社会经济因素相比,建成环境因素对私家车碳排放的影响更为显著,公共交通可达性水平的提高和职住距离的缩短虽然有助于降低私家车出行概率,但对私家车碳排放的减少并无显著影响,而提高居住地人口密度、完善商服设施供给、促进周边土地利用的多元化则可有效降低长距离的出行需求,减少碳排放量。     

基于GM（1，1）模型群的福建铁路货运量预测

铁路货运量是确定铁路交通基础设施建设规模的主要依据,货运量预测结果的合理性、可靠性直接影响铁路工程项目的投资和效益。本文根据福建省铁路货运的发展状况,收集T2001-2010年的货运量数据,采用多个灰色GM（1,1）模型群对福建省铁路货运量进行模拟、预测。经过模型精度检验,最后选择新陈代谢GM（1,1）模型对未来三年内的福建铁路货运量进行预测。     

郑州城市居民交通碳排放的时空特征

居民交通出行及其碳排放研究对制定有针对性的城市低碳交通政策具有重要意义。本文对中原经济区的中心城市郑州市居民交通出行开展微观调研,结合统计数据分析居民交通碳排放的时空变化特征和影响因素。研究显示:2001-2011年,虽然公交车、出租车的碳排放在平稳增加,但由于小汽车的快速增长和频繁使用造成郑州城市居民交通碳排放量呈指数增长态势,并且居民交通碳排放结构从出租车占主导、公交车和小汽车为辅逐渐演变为小汽车占绝对优势、公交车和出租车处于从属的格局。少数家庭对小汽车的过度使用使得居民交通碳排放存在显著的等级差异和家庭差异。不同等级碳排放的家庭在空间上呈现出明显的空间分异特征,即碳排放总量和小汽车碳排放量高的家庭散落于中心城区和外围市区的东部边缘,在向心型城市化影响下公共交通碳排放则呈中间低、外围高分布。居民家庭收入水平对公共交通和小汽车碳排放的影响分别为负效应和正效应,表明居民家庭在收入较低时倾向于借助公共交通出行,随着收入的增加会优先选择小汽车。     

浅谈铁路货运规章信息化建设

铁路货运规章是铁路货物运输的基本"法",但现行的铁路规章数量众多、修改频繁、不便于现场使用。文章对目前铁路货运规章管理存在问题进行分析,提出采用信息化手段管理规章,并对货运规章管理系统建设提出建议。     

大数据时代数字资源整合方法研究:模型设计和实验分析——以物流行业为例

[目的/意义]针对目前大数据时代数字资源的非结构化、海量、多类型等问题,设计一套数字资源整合的模型和方法,以满足信息用户的实际需求。[方法/过程]以物流行业中的航运信息服务产品集装箱运价指数为例,提出基于大数据的指数编制思路,以数据仓库模型为目标数据模式,构建面向海量多源异构信息的数字资源集成模型,设计Web类数字资源获取和集成流程以及增量数据的处理方法,通过具体实证研究检验模型和流程的运行效果。[结果/结论]实证结果显示,本文提出的数字资源整合模型和处理流程能有效地实现多源异构数字资源的整合,支持基于海量数据对的指数编制模式,为全世界各类指数编制的改变提供理论和技术方面的探索,也为数字资源整合在其他领域的应用提供有益参考。     

Distributed cruise control of high-speed trains

In this work, the cruise control problem of high-speed trains’ movements is investigated. Both cases of a single high-speed train and multiple high-speed trains are under consideration. Different with most existing studies where the centralized control or the decentralized control methods are adopted based on a single point mass model of the train, in this paper, a distributed control mechanism is proposed by virtue of the graph theory, and the high-speed train’s model is built as a cascade of point masses connected by flexible couplers. For a single high-speed train, the neighboring cars interact through the coupling force with each other, which can be described by a connected topological graph by regarding each car as a node. Besides, the speed information communication among the cars is considered to be described by another directed topological graph. A distributed control strategy is then developed, with which all the cars of a train track a desired speed asymptotically and the neighboring cars keep a safety distance from each other. For the multiple high-speed trains running on a railway line, the in-train force interaction topology and the speed information communication topology of all the trains are more complex than those of a single train. A new cluster consensus technique is developed, by which a distributed control law is designed. Under the control law, the trains can track the desired speeds asymptotically, the headway distance between adjacent trains and the distance between the neighboring cars of a train can be kept in appropriate ranges. Finally, simulations are provided to illustrate the effectiveness of the obtained theoretical results.     

沈阳市交通生态足迹的时间序列分析

对沈阳市交通足迹总体形势、各种交通工具的生态效率变化进行了较为详细的分析,研究结果表明：①沈阳市1995年～2004年交通足迹连年增加,且其增长率高于客运量,环境恶化速度快于经济增长速度;②总的看,沈阳市交通的生态效率有所提高,但近几年出现下降趋势,分析其主要原因在于对客运量贡献最大的公共交通生态效率这期间出现了下降的趋势;③无论从总量上还是增长率,小轿车对城市交通足迹均有较显著的影响,是对交通足迹贡献最大的交通工具。由于交通生态效率最低、环境压力指数远高于其他交通工具,小轿车对沈阳市交通环境压力的影响和冲击最显著（其他交通工具相对较小）。通过沈阳市地铁工程运营前后情景预测和对比可知,地铁工程将能缓解沈阳市未来交通环境的压力。     

基于可配置产品平台的汽车选装配置管理技术研究

通过对比欧洲及国内某汽车企业乘用车选装配置能力,揭示国内汽车行业BOM管理面临的挑战。相对于汽车行业传统的BOM管理模式,提出可配置BOM的概念,研究比较可配置BOM的两种构建模式及其优缺点,并通过产品数据管理软件验证了基于可配置BOM的选装管理技术和能力。     

高速公路驾驶员安全心理研究

高速路事故发生主要由驾驶员的不安全行为与车辆不良性能造成,驾驶员的心理素质与其安全行为关系密切。本文以芙蓉西高速公路为实例,实测驾驶员行驶过程中的心率变化,以及事故发生原因调查。对实测结果与调查原因进行驾驶员心理分析。分析得出：驾驶员心理负荷同路段有很大关系,事故多发生于货运车辆,事故发生于驾驶员的心理承受能力有关。鉴于此,本文在增强驾驶员心理承受能力方面引进了安全心理分析。     

国际贸易商务协同业务管理服务系统的研究与设计

本文以国际贸易商务协同理论为基础,以基于管理的协同商务的服务联盟模式思想、体系与方法为对象,以重点解决生产企业与贸易企业、生产／贸易企业与电子商务平台、生产／贸易企业与货代物流企业、货代物流企业之间、承运人与运输企业等各贸易相关方之间的信息共享与业务系统管理为目的,研究设计国际贸易商务协同业务管理系统。     

面向交通运输体系构建的货运量定量预测方法研究

文中研究面向交通运输体系构建的交通货运量的定量预测方法,分别对货运量预测中常用的时间序列预测法、趋势外推预测法、相关回归预测法和灰色预测法进行了简要的介绍说明,时间序列预测法假设预测对象仅与时间有关,是对外部因素复杂作用的简化;趋势外推法比较适合中、长期预测。使用回归分析等预测方法要考虑到各种影响因素;灰色预测法多适用于近期货运量预测,对于远期预测偏差较大。     

基于灰色神经网络的公路物流需求量预测模型

以浙江省公路货运量历史数据为例,考虑到影响货运量主要因素,采用灰色神经网络模型GNNM(1,N)进行预测,并与灰色模型GM(1,N)和神经网络预测结果相比较。计算结果表明:该方法在预测公路物流需求量具有有效性;在灰色模型GM(1,N)预测时,通过比较紧邻均值生成序列的生成系数α对预测精度的影响,选取了最优值进行计算从而提高了灰色模型的预测精度。     

Dominance in the prototyping phase—The case of hydrogen passenger cars

The notion of dominant designs refers to dominance in the market, hence the literature on dominant designs ignores the selection process that already takes place in pre-market R&D stages of technological innovation. In this paper we address the question to what extent pre-market selection takes place within an industry and how this may lead to dominance of one design over others before the market comes into play. Furthermore we study what selection criteria apply in the absence of actual market criteria. We do so through a historical analysis of design paths for hydrogen passenger cars.We argue that prototypes are used by firms in their internal search process towards new designs and at the same time as means of communicating technological expectations to competitors and outsiders. In both senses, prototypes can be taken as indicators of design paths in the ongoing search process of an industry.We analyzed the designs of prototypes of hydrogen passenger cars from the 1970s till 2008. A database is compiled of 224 prototypes of hydrogen passenger cars, listing the car's manufacturer, year of construction, hydrogen conversion technology, fuel cell type, and capacity of its hydrogen storage system. The analysis shows to what extent one design gained dominance and which strategies were adopted by the firms in their search processes.We conclude that indeed a dominant prototyping design has emerged: the fuel cell combined with high pressure gaseous storage. Actual and expected performance acted as selection criterion, but so did regulation and strategic behaviour of the firms. Especially imitation dynamics, with industry leaders and followers, is a major explanatory factor. Our main theoretical claim is that the selection of a dominant prototyping design is based on an interaction of sets of expectations about future performance of technological components and regulatory pressure that results in herding behaviour of the firms.     

How can we know a self-driving car is safe?

Self-driving cars promise solutions to some of the hazards of human driving but there are important questions about the safety of these new technologies. This paper takes a qualitative social science approach to the question ‘how safe is safe enough?’ Drawing on 50 interviews with people developing and researching self-driving cars, I describe two dominant narratives of safety. The first, safety-in-numbers, sees safety as a self-evident property of the technology and offers metrics in an attempt to reassure the public. The second approach, safety-by-design, starts with the challenge of safety assurance and sees the technology as intrinsically problematic. The first approach is concerned only with performance—what a self-driving system does. The second is also concerned with why systems do what they do and how they should be tested. Using insights from workshops with members of the public, I introduce a further concern that will define trustworthy self-driving cars: the intended and perceived purposes of a system. Engineers’ safety assurances will have their credibility tested in public. ‘How safe is safe enough?’ prompts further questions: ‘safe enough for what?’ and ‘safe enough for whom?’