• IE interfaces
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• v.20 no.2
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• pp.204-215
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• 2007

This paper addresses vehicle routing planning in freight container transportation systems where a number of loaded containers are to be delivered to their destination places. The system under consideration is static in that all transportation requirements are predetermined at the beginning of a planning horizon. A two-phased procedure is presented for freight container transportation. In the first phase, the optimal model is presented to determine optimal total time to perform given transportation requirements and the minimum of number of vehicles required. Based on the results from the optimal model, in the second phase, ASA(Accelerated Simulated Annealing) algorithm is presented to perform all transportation requirements with the least number of vehicles by improving initial vehicle routing planning constructed by greedy method. It is found that ASA algorithm has an excellent global searching ability through various experiments in comparison with existing methods.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.185-192
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• 2012

Line planning is to determine the frequency of trains on each line to satisfy origin-destination demand while minimizing total operation cost. However, different from the line planning in passenger transportation, it is more important at which intermediate stations each train should be stopped and shunted because the freight car handling works like drop-off or(and) pick-up can incur much time and high cost so that the delay deteriorates the quality of rail freight transportation service. We present an optimization model for constructing line plan in rail freight transportation to simultaneously minimize the train operation cost and total transportation time of freights. And we suggest a column generation approach for our problem, which can solve the real network instances in reasonable computation times.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.65-71
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• 2005

Area type is often used in freight demand analysis and logistics planning models. For example, in freight transportation planning. area type variable is most often commonly used in freight generation (attraction) model. Yet a reliable, forecastable and measurable definition or area type is generally not documented. In fact, there is little literature on the subject of predicting area type in the context of freight planning models. This can be troublesome when applying models to long-range logistics planning where significant changes in population and employment result in changes in the general character of an area. Through the use of Discriminant Model, GIS (Geographic Information System) analysis and Delphi methods, this paper presents the successful exploration for a quantifiable means of determining area type.

• Journal of Korea Port Economic Association
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• v.22 no.1
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• pp.175-198
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• 2006

This paper presents a network capacity model that can be used as an analytical tool for strategic planning and resource allocation for multimodal transportation systems. In the context of freight transportation, the multimodal network capacity problem (MNCP) is formulated as a mathematical model of nonlinear bi-level optimization problem. Given network configuration and freight demand for multiple origin-destination pairs, the MNCP model is designed to determine the maximum flow that the network can accommodate. To solve the MNCP, a heuristic solution algorithm is developed on the basis of a linear approximation method. A hypothetical exercise shows that the MNCP model and solution algorithm can be successfully implemented and applied to not only estimate the capacity of multimodal network, but also to identify the capacity gaps over all individual facilities in the network, including intermodal facilities. Transportation agencies and planners would benefit from the MNCP model in identifying investment priorities and thus developing sustainable transportation systems in a manner that considers all feasible modes as well as low-cost capacity improvements.

• IE interfaces
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• v.16 no.2
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• pp.174-184
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• 2003

This paper addresses a fleet operation planning problem for a static freight container transportation system in which all the transportation requirements are predetermined at the beginning of a planning horizon. In the transportation system under consideration, a number of loaded containers are to be moved between container storage yards. An optimal fleet planning model is used to determine the minimum number of vehicles required. Based on the results from the optimal model, a tabu-search based algorithm is presented to perform a given transportation requirements with the least number of vehicles. The performance of the new procedure is evaluated through some experiments in comparison with two existing methods, and the it is found that our procedure produces good-quality solutions.

• Journal of Korean Society of Transportation
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• v.3 no.1
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• pp.58-75
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• 1985

On facing the information society, the multi-faceted information utilization and the establishment of synthetic information management system in the overall industry and business administration have raised considerable attention. Thus, this study aims at the improvement of freight transport management through the establishment of pooling of the road freight transport information system as its effective information supporting system. Especially, it describes the freight transport information network, structure, function, and subject of the freight transport information center, as a basic planning design for the freight transport information system. Furthermore, it deals with the identification of the systems design requirements, working process, and S/W & H/W design specifications. Finally, we expect that this study will be contributed for the improvement of the road freight transport business to meet both the increase of freight transport demands due to the continuing economic growth and the social needs for the establishment of transport-order.

• IE interfaces
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• v.11 no.1
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• pp.1-14
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• 1998

Various problems on logistics systems have been dealt with recently as research issues since they were regarded critical for taking up a better position in the increasingly competitive global market. In particular, the freight transportation is considered as a key factor which affects the economic competitiveness of a whole nation as well as the production cost of individual companies. The objective of this study is to identify main issues and review recent foreign and domestic studies related to the freight transportation. The studies are classified into two categories according to the hierarchical level in the decision making process: infra structure design and transportation strategies, service design and operation. Main issues are introduced with a brief review on the related literature and methodologies applied.

• IE interfaces
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• v.13 no.3
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• pp.471-478
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• 2000

One of the most important problems encountered by parcel transportation firms or LTL (Less-than-truckload) firms is the planning of daily linehaul operations. The transportation firm's goal is to determine the most efficient way to move all freight from its originating terminal to its destination terminal after each shipment is picked up from the shipping dock. The purpose of this study is to design a transportation system and develop an efficient scheduling algorithm for linehaul operations carrying small amount of shipment. This paper presents three approaches for efficient linehaul operations. The first approach examines drivers using the roundtrips which start from a terminal, visit several terminals, and return to the starting terminal. The second approach uses a freight assembly center where drivers take freight for a number of destination terminals which they then swap for freight for their starting terminal. The third approach is similar to the second approach in that it uses a transshipment point like a freight assembly terminal for shipment, but it has several transshipment points since each shipment may have a different transshipment point. In this study, we developed a mathematical formulation and algorithm for each approach. The experimental results using data of a LTL firm show that the third approach is more efficient than the other two. Mileage and overnight stays of the third approach are reduced by 10% and 30%, respectively.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.138-143
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• 2013

Recently, the demand for rail freight has gradually decreased. In particular, the demand in Korea for open freight cars, which classification includes gondola cars, hopper cars and gravel cars has been significantly reduced. The role of gondola cars in the rail transportation market shrank to 14.5% in 2010 from 23.3% in 2001. The transportation demand of gondola cars in the long term is expected to be reduced further. Because some gondola cars have been converted to container cars and various containers are being developed to transport bulk cargo by container cars. However, gondola cars still play an important role in rail freight transport. Therefore, the management planning of gondola cars is needed in order to prepare for the long-term declining demand. In this study, we propose a future direction for the management planning of gondola cars through the effectiveness analysis of gondola cars operation.

• Asian Journal of Innovation and Policy
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• v.11 no.1
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• pp.110-147
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• 2022

Many megacities are exposed to natural hazards such as earthquakes, and when located in coastal regions, are also vulnerable to hurricanes and tsunamis. The physical infrastructures of transportation systems in megacities have become so complicated that very few organizations can understand their response to extreme events such as earthquakes and can effectively mitigate subsequent economic downfalls. The technological advances made in recent years to support these complex systems have not grown as fast as the rapid demand on these systems burdened by population shift toward megacities. The objective of this paper is to examine the risks imposed on and recoveries of transportation systems in megacities as the result of extreme events such as an earthquake. First, the physical damage to transportation infrastructure, loss of the transportation system performance, and the corresponding economic loss from disruptions to passenger and freight traffic is evaluated. Then, traffic flows are re-routed to reduce vehicles' delay due to earthquakes using a microscopic traffic flow simulator with an optimization model and macroscopic terminal simulator. Finally, the economic impact of the earthquake is estimated nationwide. Southern California is regarded as the region of study. The results demonstrate the effectiveness of the integrated model and provide what and how to prepare innovative resilience policies of urban infrastructure for a natural disaster occurrence.