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21.
The level of service of a bus line is evaluated by its operational characteristics, particularly by the ratio between average bus travel time on a given route and the average passenger car travel time on the shortest distance between the origin and the destination of the bus in question. It is shown that the level-of-service measure may be predicted by such independent variables as route length, average distance between bus stations, number of signalized and unsignalized intersections, and the ratio between such intersections. It is hypothesized that use of other independent variables such as boarding and alighting passengers, or volume to capacity ratio on the route concerned, could improve the predictive power of the suggested models. Further research is recommended on the effect of these latter variables and other operational variables which might influence bus level of service, and also on the comparison between direct bus lines and lines which use transfer points. 相似文献
22.
ABSTRACTThe impacts of air transport on the economy arise both directly, via activity in the aviation sector; and indirectly, via increased spending and wider economic benefits associated with improved access to resources, markets, technology and economic mass. Economic activity, in turn, supports and generates demand for air transport. Despite its potential importance, the reciprocal nature of the causal relationship between air transport and economic performance has remained somewhat understudied. This paper provides a synthesis review of the channels the aviation sector interacts with regional economy. The review focuses on quantitative studies that contribute to the state-of-the-art understandings of the causality. We find that the reciprocal causal relationship is more likely to prevail in less developed economies. For more developed economies, only one direction of the causality is recognised, which runs from air transport to economic growth. Especially substantial is the effect of airline enplanement on service-related employment. The reverse direction of the relationship is, however, not as significant as believed in a causal sense within the developed world. Therefore, cautions need to be taken when applying income elasticities (such as the elasticity of air passenger demand with respect to GDP) in air travel demand forecasting, which implicitly assumes that economic growth causally leads to air traffic increment. Based on the fundamental links between air transport and economic growth, some typical imperfections and inefficiencies in aviation markets are discussed and promising avenues for future research are proposed. 相似文献
23.
Transportation - The paper studies a general bidirectional public transport line along which demand varies by line section. The length of line sections also varies, and therefore their contribution... 相似文献
24.
Daniel Puente-Rodríguez 《Coastal management》2013,41(5):426-446
Participation (e.g., stakeholder involvement) has become a central concept in the practice of environmental and coastal zone management. Research has shown that the integration of participation in coastal zone management has positive ecological and social outcomes. In the literature, however, participation is often reported in an unstructured and uncritical manner. Therefore, to find out whether and how there is a useful way to structure and characterize the way the coastal zone management literature deals with participation, we have conducted a literature review. The review was conducted and the literature structured through three central dimensions of participation, namely: power, knowledge, and (visions of) nature. The article concludes that this structured approach to participation enables us to study more systematically the role of participation and might facilitate the governance and learning processes of coastal networks. 相似文献
25.
H. J. Kim M. W. Song H. I. Moon H. Kim H. Y. Kim 《International Journal of Automotive Technology》2014,15(2):317-324
This paper suggests a fatigue life calculation method (A fatigue life calculation method is suggested) for rubber components based on the dynamic crack growth considering shear effect. Dynamic tearing tests were carried out, and the crack length was measured using an optical microscope to calculate the dynamic crack growth rate which characterizes and determines the fatigue life. The algorithm was numerically implemented in finite element code, ABAQUS standard, by using the user subroutine and applied to several rubber components. In the finite element analysis, deformation mode of an element was classified into tension and shear, and a weighting factor was multiplied to a strain energy density according to the degree of shear strain. Tension and compression of an elliptic dumbbell specimen was simulated in order to verify the material parameters of the suggested fatigue life prediction equation and to enhance the reliability of the algorithm. Finally, the fatigue life of a vehicle suspension bushing was calculated and compared with test. There were good agreements in the failure location and the magnitude of the fatigue life. 相似文献
26.
In Britain, capacity charges are levied on train operators to cover the costs imposed by increased reactionary delays – i.e. the delay that an already late train causes to a following train. These charges are based on the link between capacity utilisation and the level of reactionary delay. An established method for measuring capacity utilisation was adopted called The Capacity Utilisation Index (CUI). In this paper, we propose an alternative methodology based on the theory that the level of reactionary delay will be determined by the minimum gaps that exist between trains. We test this measure with a new data-set for the East Coast Main Line and show that it performs better than CUI. Finally, we comment on the implications of this finding for charging and for the construction of timetables. 相似文献
27.
Daniel J. Mayor Thomas R. Anderson David W. Pond Xabier Irigoien 《Journal of Marine Systems》2009,78(4):505
We present concurrent data on ingestion, egg production and the loss of maternal biomass in pre-spring bloom female Calanus finmarchicus incubated under conditions representative of those in situ in the North Atlantic. A balanced metabolic budget was constructed and used to examine the relative importance of ingestion and biomass for fuelling egg production during the incubations. Ingested carbon was not sufficient to meet the observed demands for egg production. More than 80% of the carbon utilised by the females was instead derived from their biomass. Fatty acid analysis demonstrated that the storage reserves, 20:1 (n−9) and 22:1 (n−11), were virtually absent before experimentation began, and therefore could not have been used to supply the carbon required for egg production during the incubations. The C:N mass-specific ratio of the biomass utilised was 4.1, suggesting that the females had instead catabolised protein in order to meet their metabolic demands. These results suggest that C. finmarchicus adopts a sacrificial reproductive strategy when food availability is low. 相似文献
28.
Seong-Hyeok Moon 《Maritime Policy and Management》1995,22(4):363-387
The provision of adequate port capacity has been essential for Korean economic development, as its foreign trade has been predominantly seaborne. In this respect, efforts have been directed to the development of seaports in order to provide a sufficient level of service for greater national control of foreign trade. The port planning and development process in Korea, however, has not been a total success. This is underlined by the fact that the seaport industry in Korea has not coped with the increased demand, and total seaport capacity has lagged behind need. This paper examines the validity of the port input-output model (PIM) as predictive tool to future planning. Further the value of the PIM as a forecasting tool to the port transport industry in Korea is identified. 相似文献
29.
The authors examine the problems of transportation planning for special events such as Worlds Fairs, Olympic Games etc., and use as a case study the experiences gained at EXPO 86 in Vancouver. Results indicate that sufficient flexibility exists in the urban infrastructure to accommodate the transport access and parking requirements of major, short‐term special events. 相似文献
30.
Abstract In the early 1970s, Seattle Piers 90/91 were declared surplus federal property by the GSA. These obsolescent half‐mile‐long piers and their adjacent uplands were purchased by the Port of Seattle for redevelopment. This urban waterfront site of almost 200 acres presents the Port of Seattle with a number of severe planning problems. While it is the last large deep‐water site on Elliott Bay, it is also in a very sensitive location, since it is overlooked on two sides by vocal residential communities with a history of active intervention in development projects on visual and other environmental grounds. At Piers 90/91, public concerns over the visual effects of port redevelopment include: 1. nuisance effects of night‐operations lighting on adjacent hillside residences; 2. nighttime obstruction of distant views due to increased foreground illumination; 3. day and night view obstruction by tall structures such as container‐handling cranes; 4. alteration of the character of both day and nighttime views by new port facilities. As part of a program to study the effects of alternative redevelopment strategies for Piers 90/91, the Port has undertaken a through examination of the visual effects of different uses, their visual appropriateness, and the ways by which adverse visual effects can be mitigated. The results were incorporated into an environmental impact statement which documented compliance with the Seattle Shoreline Master Program and with view protection and glare provisions of the City's S.E.P.A. guidelines. A systematic Visual Resource Management (VRM) approach was successfully employed on this coastal zone project. Major elements included visibility mapping, key view selection, analysis of existing visual character, simulation of alternatives, assessment of relative visual compatibility, and determination of effective mitigation measures. Community involvement has also been a critical element in this approach to assessing and managing the visual effects of redevelopment in a major urban port. 相似文献