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Transportation - Active modes (i.e. walking and cycling) have received significant attention by governments worldwide, due to the benefits related to the use of these modes. Consequently,...  相似文献   
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Graphics are a powerful but often costly means of communication. Computer‐drawn graphics offer a new and relatively inexpensive way to assist the communication of complex technical information to both planners and non‐technical people whose full potential is now beginning to be realized. This paper discusses the utility of graphics and introduces three computer‐drawn graphic techniques which may be useful, both for analysis and presentation of results, in the transportation planning process. CENVUE(S) produces a three‐dimensional, perspective‐view map, on which virtually any type of transportation data or performance indicator can be displayed. VAP is designed to display origin‐destination travel patterns in any region. TDN transforms a physical‐distance network into a time‐distance network so that effects of different speeds in the transportation network can be readily seen. The cost‐effectiveness of each technique is briefly discussed and some recommendations for evaluating computer graphics techniques are provided to aid the user in further assessing their utility in the transportation planning process.  相似文献   
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Short-line railroad managers discuss their industry   总被引:1,自引:0,他引:1  
In the United States, the 1980 Staggers Rail Act created a positive regulatory environment for the creation of new short-line railroads. At present there are about 450 of these railroads that have less than 250 miles of trackage. This study asked managers/owners of these railroads two basic questions. First, what do you believe is the single most important trend that is currently taking place in your industry. The most frequently noted trend was the frustration of working with the larger Class 1 railroads. Five additional trends were also identified by the respondents. The second question asked the respondents if they thought the short-line sector of the rail industry will become more or less important in the next ten years and why. About 70% of the owner/managers believed their industry would become more important in the next decade. The most commonly expressed reason for this position is that the Class 1 railroads will increasingly specialize in mainline service only. Three other rationales were also enumerated. For the managers that thought their industry would become less important, the most noted reason was their trackage would not safely transport the newer very heavy bulk commodity freight cars.  相似文献   
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Two alternative methods for conducting a preliminary analysis of the problem of locating and sizing park-ride lots for an urban bus transit system are examined. These alternative methods are tested using a large and complex street network representing the northern half of the City of Seattle, Washington. Four design criteria are identified and an overall measure of system performance is devised. The problem is to determine the size and location of three park-ride lots that will maximize the performance of the system. The first method utilizes a computing system called LOCATOR II in an interactive graphic mode. In an experimental setting, five students use LOCATOR II to locate three park-ride lots and their solutions are found to exhibit a very high average level of performance. The second method does not involve a direct interaction with the computing system but does use LOCATOR II in a batch mode. Several students participate in three rounds of the batch mode experiment and the performance of their designs is somewhat poorer than the designs found in the interactive graphics experiment. Overall, the experimental results show that relatively inexperienced persons can find a high performance design for a reasonably complex problem quickly and inexpensively. These designs can provide a good starting point for the detailed consideration of many of the other aspects of the problem of providing a high performance bus transit service in an urban area.  相似文献   
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A summary of the seasonal development of the Northeast Water Polynya ice cover characteristics is presented. This is based primarily on satellite remote sensing observations, with some in situ measurements, including both new and published data.  相似文献   
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The structure and nature of Norske Ø Ice Barrier, the southern boundary of the Northeast Water summer polynya, is deduced from Landsat 5 TM images. Within the barrier, three main areas are identified: glaciers to the west, a permanent central ice region made up of fast ice and a variable zone of attached pack ice.  相似文献   
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In this article we use a multi-scale, multi-method historical reconstruction of post– World War II social-ecological interactions within fisheries in Newfoundland and Labrador to explore the dynamics of intensification, expansion, and resource degradation in managed fisheries. Our case study draws on landings statistics, other archival information, and the Local Ecological Knowledge (LEK) of fish harvesters to explore these linked dynamics at the macro, meso, and micro levels. By some measures we found large scale trends toward intensification of effort leading to over-harvesting at macro (province wide) levels. At the same time, at the local level (micro-scale) and across sectors and regions (the meso-scale), we found highly fluid fishing practices and a complex suite of stated motivations for change. As a basis for effective governance, an understanding of the dynamics of interactive restructuring in social ecological systems will require multi-scale analyses that are sensitive to this complexity.  相似文献   
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