北斗导航运输信息安全传输方案探讨

信息安全传输在北斗导航运输系统中存在比较大的缺陷,对开发北斗卫星导航运输业务的应用系统产生了不利影响,有必要对此进行弥补和改进。在分析运输业务现存问题和SSL协议基本原理的基础上,结合北斗卫星导航技术和SSL安全协议的特点,提出进行运输信息安全传输的解决方案,并指出实施解决方案的流程和SSL协议的工作过程。     

影响交通运输行业信息披露质量的因素研究——基于深交所2001-2012年经验数据

从公司特征、董事会特征和监事会规模三方面研究影响我国交通运输行业上市公司会计信息披露质量的因素。以2001~2012年深圳证券交易所交运业19个上市公司为样本,采用加权最小二乘法进行拟合,通过这个实证分析方法分析深交所交通运输行业信息披露质量的影响因素,为提高其信息披露质量提供依据。     

基于遗传算法的物流运输与调度优化研究

物流优化是物流企业降低物流成本的主要方式之一,通过物流优化进一步提高物流公司的服务能力,已经是许多物流企业提升竞争力的一项有效举措。本文依据现实中的物流运输问题,建立了基于运输成本和时间的一般函数模型,利用遗传算法进行求解,寻求最优运输路线。算例结果表明使用遗传算法优化运输方式,可以改善现有的调度模式,在满足时间约束的条件下,实现物流运输成本最小。     

非开挖定向钻孔铺管技术的运用

当今社会的快速发展,造成城市既有配套设备不断更新,遍布于大街小巷的通信、电力线路首当其冲。新建铁路、公路、隧道等工程要求对影响施工的通信、电力线路进行迁改。多数情况下,受现场环境和征拆因素影响,通信、电力线路迁改路径复杂,迁改施工难度大、进展慢,直接影响城市建设和工程顺利进行。非开挖定向钻孔铺管技术的引入,可以有效地解决市区通信、电力线路迁改路径复杂的问题。通过非开挖定向钻孔铺管技术,将架空线改为地埋敷设,既不损坏地面设施,又可以大大降低迁改施工成本。该文对非开挖定向钻孔铺管技术在新建铁路通信、电力线路迁改施工中的作用及其施工工艺作简要阐述,以推广此项技术的应用。     

莱钢1080m~3高炉气力罐车输煤的应用与实践

气力罐车输煤适于长距离煤粉输送,因其存在涉及生产线多、不适合短距离输送等缺点,在我国钢铁企业中应用并不广泛。为满足高炉正常喷吹的需求,莱钢1080m3高炉喷煤系统,采用了一种多功能气力输送罐车(吸排车)进行煤粉短期6km长距离运输实践,期间保证两座1080m3高炉煤比达到110kg/t铁左右,高炉利用系数2.6t/m3d。     

治理车辆超限预检系统应用节能减排的效果研究

公路超限运输是我国道路运输行业面临的重要问题。随着这一问题的日益突出及其危害的愈加严重,交通公路执法部门通过经济、行政、法律、技术等各种手段加大对违法运输车辆的治理力度。公路超限检测站是超限运输治理中的一个重要环节,而目前,我国各个公路超限检测站主要采用人工拦截,入站执法的管理模式,费时费力,一线执法人员的人身安全很难得到保障。亳州市公路局不断探索治超模式,积极推进科技治超工作,与相关单位协作,共同研究运用公路运输车辆超限超载不停车预检系统,大量节省了人力物力,取得了良好的经济效益和社会效益。     

旅游运输通道演化对区域旅游空间模式的影响机理——以云南省为例

在分析运输通道类型与特征的基础上,从通道的运输能力、技术装备水平和交通服务水平三个方面,定义了旅游运输通道演化的三个阶段,即完备型旅游运输通道、发展型旅游运输通道和滞后型旅游运输通道;并在分析旅游运输通道演化机制的基础上,对云南省旅游线路进行统计分析,从旅游运输通道演化对旅游景点出现率、旅游线路选择集中度、旅游线路重复系数、旅游线路空间模式四个方面,实证分析旅游运输通道演化对区域旅游空间模式的影响机理。研究结果表明:1旅游运输通道技术装备水平和交通服务水平的改善能提高旅游景点选择率;2旅游线路的选择集中度随着通道发展程度的改善而逐渐增大,而区域内其他通道的演化会在一定程度上抑制其增长幅度;3旅游运输通道的发展程度与旅游线路重复系数具有一致性;4旅游运输通道内交通方式的完善使得交通服务水平提升,进而对旅游空间模式产生影响。     

公司融资结构与公司治理及在中国的特点

公司融资结构与公司治理有重要的联系 ,而融资结构的合理安排对公司的代理关系和治理结构将产生重要影响。从不对称信息的角度出发 ,通过詹森、麦克林 (1 976 )的委托代理理论和梅耶斯、迈基里夫(1 984 )的融资优序理论来说明公司融资结构与公司治理的关系 ,并进一步分析中国上市公司融资偏好的特点和原因     

Environmental Costs and Responsibilities Resulting from Oil Exploitation in Developing Countries: The Case of the Niger Delta of Nigeria

Interest shown on the environmental impact of operations of multinational enterprises in developing countries has grown significantly recently, and has fuelled a heated public policy debate. In particular, there has been interest in the environmental degradation of host communities and nations resulting from the operations of multinational oil companies in developing countries. This article examines the issue of environmental costs and responsibilities resulting from oil exploitation and production in the Niger Delta region of Nigeria. The case study is based, in part, upon series of interviews with key stakeholders in the Nigerian oil industry. The article further examines the implications of the current practice and policies of multinational oil companies with respect to environmental impact of oil exploitation. The study’s findings illustrates that it is becoming increasingly apparent to oil companies that pollution prevention pays while pollution does not and under pressure from stakeholder groups, oil companies now routinely incorporate environmental impact assessments into their corporate strategy.Dr Gabriel Eweje is a lecturer in Management and International Business at College of Business, Massey University, Auckland Campus, New Zealand. Previously, he worked as a Research Fellow at the United Nations University, Institute of Advanced Studies (UNU/IAS), Tokyo, Japan, and taught at Royal Holloway University of London, England. His PhD from University of London focused on Corporate Social Responsibility and Activities of Multinational Oil and Mining companies in Developing Countries. He also worked as a Research Fellow with International Institute for Environment and Development (IIED), London on a project on how mining and minerals can contribute to sustainable development (MMSD). His research interest lies around the issues of business ethics, corporate social responsibility and sustainability related disciplines.     

Trade Credit in Small and Medium Size Firms: An Application of the System Estimator With Panel Data

Financing through suppliers is a subject that has been little studied in the economic literature in general and in corporate finance in particular. Although several hypotheses have been put forward to explain the different reasons behind this phenomenon, trade credit is not based on a general theory. This study provides empirical evidence about factors determining the use of trade credit for a sample of small and medium size firms, which are potentially the firms that would follow this financing route, since they are more rationed in credit markets. Using a panel of Canary-Island firms from 1990 to 1996, and by means of specifications with the system estimator, results reveal that trade credit leads to a reduction in asymmetric information between firms and their financial backers, as well as in transaction costs. Furthermore, we confirm the theory that companies with easier access to institutional finance act as a credit channel for those with greater difficulties to obtain external funds.