• 대한교통학회지
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• 제5권2호
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• pp.37-54
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• 1987

The methods of the transportation plan evaluation have appearently been improved. Yet we are frequently confronted with many problems when we are trying to apply those various methods in practice. This paper aims at reviewing the major problems in the transportation plan evaluation and considering the way to resolve such kinds of problem. The selection of the evaluation criteria and the weighting systems between such criteria are the moat important things in the multi-criteria approaches. In this respect, this paper suggests some alternative evaluation criteria in consideration of the levels and the purpose of the plan. Also the increased capacities and new demands of generated trip are the main effects of the transportation investment. Nevertheless such significant effects have been neglected in the calculation of benefits due to the transportation investment in the past. Therefore this paper suggests that the surplus capacities and new demands of generated trip according to the alternative investment plans should be included in the calculation of benefits for the plan evaluation.

• 산업공학
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• 제16권2호
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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.

• 대한교통학회지
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• 제3권1호
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• pp.22-45
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• 1985

Most transportation problems are expected to be dealt with by public sector, mainly government organizations, even though few articles are available to tackle the problems from the administrative points of view. This study has the following scopes: to define the transportation system; to derive the subsystems, i.e., the functions of the system; to identify the elements (or organizations) of performing the functions; to study the inter-organizational relationships among the elements and to derive problem areas; and finally to propose a new administrative system for solving the problems. System Theory was exclusively used for defining the system and deriving subsystems of transportation. Laws and regulations about government organizations were analyzed to identify the relevant organizations. Communications analysis was used for deriving the relationships among the organizations. Ledger books containing incoming-and-outgoing documents in the sampled organizations were inputed onto computer. Exactly 49,367 records(i.e., information flows) were stored for this analysis. Finally, this study proposed a new administrative system that is expected to result in more cooperative and productive inter-organizational relationships among the transportation organizations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.763-768
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• 2007

Korean railroad has been accomplished the structural change through separating of facilities and operation of railroad in 2004. The existent government organization was transformed into the public, this caused problem of renovation of railroad management. Korean railroad has been the integrated management of passenger and freight. As putting the passenger service as a priority, freight transportation have fallen behind and not attained good sales results. Restructuring in Korean railroad would bring about considerable improvement, but still not come out of the deficit operation. To find a way out of this situation, there needs to make renovation and extend new enterprise. However, to operate the railway freight transportation more competitively, make up situation that can possess competitive power fundamentally. From this perspective, the purpose of this study is to analyze the necessity for separated operation of passenger and freight railway transportation. By doing this can expect to obtain the competition power of railway freight transportation, and is a help to build up the independent management system of railway freight transportation and secure competitive high position about other transportation systems especially road.

• Journal of applied mathematics & informatics
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• 제29권3_4호
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• pp.831-846
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• 2011

There are several methods, in the literature, for finding the fuzzy optimal solution of fully fuzzy transportation problems (transportation problems in which all the parameters are represented by fuzzy numbers). In this paper, the shortcomings of some existing methods are pointed out and to overcome these shortcomings, a new method (based on fuzzy linear programming formulation) is proposed to find the fuzzy optimal solution of unbalanced fuzzy transportation problems with a new representation of trapezoidal fuzzy numbers. The advantages of the proposed method over existing method are discussed. Also, it is shown that it is better to use the proposed representation of trapezoidal fuzzy numbers instead of existing representation of trapezoidal fuzzy numbers for finding the fuzzy optimal solution of fuzzy transportation problems. To illustrate the proposed method a fuzzy transportation problem (FTP) is solved by using the proposed method and the obtained results are discussed. The proposed method is easy to understand and to apply for finding the fuzzy optimal solution of fuzzy transportation problems occurring in real life situations.

• 대한원격탐사학회지
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• 제18권5호
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• pp.263-271
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• 2002

Recently, spatial information technologies using remotely sensed imagery and functionality of GIS (Geographic Information Systems) have been widely utilized to various types of transportation-related applications. In this study, extraction programs of some practical indices, to be effectively used in transportation reference planning problem, were designed and implemented as prototyped extensions in GIS development environment: traffic flow estimation (TFL/TFB), urban rural index (URI), and accessibility index (AI). In TFL/TFB, user can obtain quantitative results on traffic flow estimation at link/block using high-resolution satellite imagery. Whereas, URI extension provides urban-rural characteristics related to road system, being considered one of important factors in transportation planning. Lastly, AI extension helps to obtain accessibility index between nodes of road segments and surrounding district areas touched or intersected with the road network system, and it also provides useful information for transportation planning problems. This approach is regarded as one of RS-T (Remote Sensing in Transportation), and it is expected to expand as new application of remotely sensed imagery.

• 한국철도학회논문집
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• 제19권6호
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• pp.833-843
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• 2016

최근 철도 화물 수송은 컨테이너 전세 열차뿐만 아니라 시멘트, 철강 등 일반 화물의 전용열차 수가 증가하고 있고, 이에 따라 영차 수송 계획은 점차 단순해지고 있다. 반면에 공화차 수송의 경우, 수송 계획 최적화 시스템의 부재로, 사령의 경험에 의해 공화차 배분이 이루어지고 있으며, 이의 효율성 여부는 검증된 바 없고, 공화차 배분을 위한 별도의 의사결정지원시스템의 필요성은 여전히 존재한다. 본 연구에서는 연구 문헌상의 공화차 배분 최적화 모형뿐만 아니라 2010년 전후로 개발 되었다가 최근 사용이 중단된 화물수송최적화 시스템(KTOCS)상의 공화차 배분 최적화 모형을 비판적으로 살펴본 후, 수송 문제를 활용한 새로운 공화차 배분 최적화 모형 및 해법을 제시한다. 이 최적화 모형은 기존 모형과 달리, 추가 제약이 있는 수송문제에 포함되는 아크를 동적으로 생성해내는 열생성 기법에 기초하고 있다. 이를 이용한 우리나라 전체 철도 네트워크에 대한 시뮬레이션 결과, 실적 상에 나타난 공화차 km를 상당히 낮출 수 있는 것을 확인할 수 있었다.

• 한국인터넷방송통신학회논문지
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• 제13권1호
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• pp.153-162
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• 2013

본 논문은 중개수송 문제의 최적 해를 찾는 가장 단순한 방법을 제안하였다. 중개 수송문제는 직접 선형계획법이나 TSM을 적용하거나 일반적인 수송문제로 변환시켜 TSM을 적용하여 최적해를 구한다. 그러나 TSM을 적용하여 최적해를 구하기 위해서는 초기해를 구하고 해 개선 과정을 거치는 방법이 어렵다. 초기해를 구하기 위해서는 NCM, LCM이나 VAM을 적용하며, 해 개선을 위해서는 MODI나 SSM을 적용한다. 본 논문은 중개수송 문제를 수송문제로 변환시키는 방법을 적용하였다. 수송문제에 대해서는 단순히 열의 최소 비용을 선택하고, 선택된 비용들에 대해 행의 비용 오름차순으로 수송량을 배정하는 방법을 적용하여 초기해를 빠르게 배정할 수 있었다. 해 개선은 보다 큰 비용에 수송량이 배정된 경우 보다 작은 비용으로 변경할 수 있는 조건을 만족하면 배정량을 조정하는 방법을 적용하였다. 제안된 방법을 11개의 다양한 중개수송 문제에 적용한 결과 10개 문제는 초기 배정만으로 최적해를 구할 수 있었으며, 단지 2개 문제만이 해 개선과정을 1개의 비용만 변경하여 최적해를 구할 수 있었다. 따라서 제안된 방법은 중개수송 문제에 대해 가장 간단한 최적해 방법으로 적용할 수 있을 것이다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.139-142
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• 2001

This study suggests an approach for determining fleet size for container road transportation with dynamic demand in Korea. With the forecasted monthly container transportation data a year, a heuristic algorithm is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost, which is based on the solution technologies used in the aggregate production planning and the pickup-and-delivery problem. Finally the algorithm is tested for the problem how the trucking company determines the fleet size for transporting containers.

• Management Science and Financial Engineering
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• 제8권2호
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• pp.33-45
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• 2002

This study suggests an approach for determining fleet size for LTL (less -than-truckload) transportation with dynamic demand for on-time supply of the parts between the assembly line in an automobile company and its part suppliers in Korea. The vehicles operated by the transportation trucking companies in Korea in general can be classified into three types depending on the ways how their expenses occur; company -owned truck, mandated truck which is owned by outsider who entrusts the company with its operation, and rented truck (outsourcing) . With the forecasted monthly production data a year, a heuristic algorithm is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost, which is based on the solution technologies used in the aggregate production planning and vehicle routing problem. Finally the algorithm is tested for the problem how the trucking company transports parts for the automobile company.