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151.
全国铁路地理信息系统应用服务共享平台的研究   总被引:3,自引:2,他引:1  
应用服务共享平台为一个三层服务体系结构,主要提供五种服务:数据提供、数据分析、数据表现、元数据以及应用集成服务。平台功能的设计主要依据表示逻辑与处理逻辑相分离、通用功能与专用功能相分离两个基本原则。平台的核心是一个包括基础服务层和应用构件层的二层体系结构。平台的关键技术是多层服务体系结构、分布式海量空间数据存取、智能空间分析与数据挖掘技术以及基于XML的元数据技术。  相似文献   
152.
Elasticities for taxicab fares and service availability   总被引:1,自引:0,他引:1  
Schaller  Bruce 《Transportation》1999,26(3):283-297
This study utilizes a unique dataset from New York City to examine the effects of taxi fare increases on trip demand and the availability of taxi service. The elasticity of trip demand with respect to fares is estimated to be –0.22; the elasticity of service availability with respect to the taxi fare is 0.28; and the elasticity of service availability with respect to total supply of service is near 1.0. These results have important implications for taxi regulatory decisions. First, fare increases do substantially increase industry revenues but at a lesser rate than the percentage increase in the fare. The implication for policy-makers is that fare elasticities must be carefully considered to obtain desired improvements in drivers' earnings. Second, service availability -- an important aspect of service quality that is generally overlooked during fare policy debates -- should be a central consideration in fare setting, given the considerable impact of fares on availability. Finally, where the supply of cabs needs to be expanded, the number of cabs can be significantly increased without harming the revenue stream of existing operators. This finding alleviates a major industry objection to issuing additional taxicab licenses.  相似文献   
153.
154.
This paper analyzes the effect of universal service policies on the airline markets of five European Union countries (France, Germany, Italy, Spain and the United Kingdom) in the period 2002–2010. Results show that airfare discount schemes for island residents raise demand and positively affect competition and the number of flights at the route level. These effects are evident in France and Italy, but are particularly marked in Spain. By contrast, public service obligations (PSOs) reduce competition on the protected routes, while their effect on the number of flights differs depending on national regulations. In Spain, routes protected with PSOs have greater flight frequencies than those on unprotected routes of similar characteristics, but in France, Italy and the UK the opposite result is found. The empirical model also finds that on routes with low-cost airlines market concentration is smaller and there is a larger number of flights. This result is relevant for the design of universal service policy, since in recent years low-cost airlines have entered a number of thin routes and have increased access to air transportation.  相似文献   
155.
Transit Traveler Information Systems (TTIS) comprise a wide range of technologies that transit agencies use to provide reliable and timely transit-related information to customers. The touch-screen interactive information kiosk is an example of these emerging TTIS technologies. This paper examines the implementation of interactive touch-screen information kiosks, known as “On the Go!” Touch-Screen Travel Stations, at Metropolitan Transportation Authority-New York City Transit (MTA-NYCT) facilities in 2011. It analyzes data from passenger intercept surveys, from the kiosks’ built-in application usage logs and from field observations to understand actual passenger utilization of the kiosks and to assess the implications for transit agencies. The field observations also made it possible to obtain a profile of kiosk users, which sheds light on the concept of the “digital divide.” The findings, presented as lessons learned, can help agencies elsewhere develop guidelines and effective strategies for implementing similar interactive transit information systems.  相似文献   
156.
Logistics performance evaluation of provinces is considered in this study. To do so, a three-step solution approach is developed: (i) determination of 16 geographic and economic indicators, (ii) using geographic information system to assign a logistics score and (iii) prioritizing the indicators and ranking the provinces using multi-criteria decision analysis tools. Proposed methodology is applied to 81 provinces in Turkey as a case study. Results show that the provinces of Istanbul, Izmir, and Hatay are the pioneers. The proposed methodology provides the ability to analyze the impacts of indicators on logistics performance and create a logistics performance map of countries.  相似文献   
157.
Area-based management approaches may be beneficial in integrating sectoral, single-purpose laws and regulations; however, these benefits may not be attained if special area designations are equally sectoral or single-purpose in nature. Over 60 types of special management areas were documented under U.S. coastal programs, and a new classification scheme was developed to allow comparisons and analyses across programs. Results indicate that requirements and incentives for special area designations under the Coastal Zone Management Act did little to standardize or influence area-based management systems associated with state and territory coastal programs. Further, the absence of clear patterns within and between coastal programs with respect to special area policies suggests a limited commitment to this important aspect of coastal management. Continued research is needed to document the effectiveness of the various area-based management approaches presented in this article.  相似文献   
158.
教学管理工作直接影响着教学质量,本文根据当前高职院校的教育形势,认为要提高教学管理效率,为教学建设与改革服务,必须实现教学管理的科学化.  相似文献   
159.
针对作战演练对电磁环境的要求,提出了基于分阶段筛选的雷达装备之间电磁干扰预测方法。采用干扰源与接收机逐对考虑的方式,极大简化了计算。并采用分阶段预测的方法,即分成:快速筛选、幅度筛选、频率筛选和详细预测四个阶段进行逐阶段分析和预测,并实现了与地理信息系统相结合的软件可视化操作。  相似文献   
160.
海事信息系统的建设为业务管理的发展提供了便捷的支撑平台,然而随之而来的信息资源安全问题也备受关注。文章从海事信息资源安全管理的现状入手,对海事信息资源的安全管理方式进行了探讨,希望借此能够对广大读者有所启发和帮助。  相似文献   
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