• 경영과학
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• 제11권1호
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• pp.51-58
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• 1994

The purpose of this study is to extend the current sensitivity analysis of the transportation problem. In this paper we present a systematic method to obtain the variation range of supplies or demands by introducing a dummy column or dummy row. By using this approach we can deal with the case of fixed demands, and the unbalanced problem that the total demand is greater than the total supply.

• 한국ITS학회 논문지
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• 제21권6호
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• pp.70-86
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• 2022

실시간 수요대응형 자율주행 버스는 자율주행 버스와 실시간 수요대응형 버스의 단점을 상쇄시킨 미래교통수단이다. 하지만 버스 기능의 고도화로 실시간 수요대응형 자율주행 버스 도입 시 영향에 관한 정량화된 연구는 활발하지 않은 실정이다. 본 연구에서는 강화학습 기반 실시간 수요대응형 자율주행 버스를 미시적 교통 시뮬레이션에 적용하여 실시간 수요대응형 자율주행 버스의 정량화된 효과평가를 실시하였다. 구체적으로 수요 변화에 따라 실시간 수요대응형 자율주행 버스가 도로 네트워크에 끼치는 영향과 이용자 대기시간을 미시적 시뮬레이션 안에서 구현하였다. 시뮬레이션 대상지로는 한국교통대학교 인근을 선정하였다. 시뮬레이션 결과, 실시간 수요대응형 자율주행 버스는 기존 노선 고정형 버스 대비 이용자 대기시간과 평균제어지체는 감소하였고, 평균통행속도는 증가하였다. 본 연구를 통해 실시간 수요대응형 버스의 도입을 정량적으로 평가하는 것이 기대된다.

• 한국항해학회지
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• 제23권4호
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• pp.63-76
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• 1999

This paper aims at developing an integrated fleet management support system for industrial carriers who usually control the vessels of their own or on a time charter to minimize the cost of shipping their cargoes. The work is mainly concerned with the operational management problem of the fleet owned by a major oil company, a typical industrial carrier. The optimal fleet management problem for the major oil company can be divided into two phase problem. The front end corresponds to the production operation problem of the transportation of crude oil, the refinery operation, and the distribution of product oil to comply with the demand of the market. The back end is to tackle the fleet scheduling problem to meet the seaborne transportation demand derived from the front end. Relevant optimization models for each phase are proposed and described briefly. Then a user-friendly integrated fleet management support system is built based on the proposed optimization models for both ends under Windows environment. A case study reflecting the practices of fleet management problem for the major oil company is carried out by using the system.

• 한국항만학회지
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• 제8권1호
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• pp.3-15
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• 1994

Most of Cities are suffering from the traffic congestion problem with the vehicles increased. Especially, the City of Pusan is experiencing the severest traffic congestion with the lower read capacity and the higher travel demand than any other cities in the country. Thus, the purpose of this study was to grasp the conditions, review the problems and finally suggest the improvements which we faced at this time for the construction of the Urban Transportation System considered in Pusan area. Based upon the results, it was concluded that firstly the Urban Transportation System(UTS) in Pusan area should be constructed by the Public Transportation System in the center of the Public Transit Modes(i.e., bus and subway), secondly the Para-transit Modes(i.e., Light Rail Transit, LRT) introduced, and thirdly the Transportation Demand Management(TDM) implemented with the expansion of the transportation facilities if possible.

• 대한교통학회지
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• 제4권2호
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• pp.15-35
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• 1986

As the population of persons and automobiles rapidly grows, parking problems also grow in large cities of Korea. The purpose of this paper is to first grasp the status of parking facilities and characteristics in large cities of Korea; and introduce new directions of CBD parking policies in north America cities: and finally recommend the adequate parking management strategies and tactics for improving parking problems in Korea. For this purpose, field survey for parking inventories, patrol survey for parking usage as observed demand and drive interview survey for parking behavior were conducted. Compared with the parking characteristics and polices of foreign cities, many differences of characteristics were found, and existing parking management policies, which should be improved, were identified. Five categories of parking management strategies were set on; a) Reasonable control of CBD parking demand, b) securing of the public parking facilities c) Promotion of privately operated parking facilities d) expansion of financial resources for parking facilities construction and e) Improvement of existing parking management system. And actural seventeen tactics to attain the above strategies were recommended.

• 한국경영과학회지
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• 제3권1호
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• pp.69-73
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• 1978

This paper deals with the problem of determining the optimal inventory-transportation policy of the idealistically simple inventory-transportation system with the following assumptions: (1) The system consists of a single central warehouse and a single local warehouse, (2) The planning horizon is finite, (3) Demand rate is fixed costant, and so forth. Developed is the algorithm by which to identify the optimal inventory policy which minimizes the total cost incurred to the system over the given finite planning horizon. A sample numerical example is presented along with a discussion of the possible applications of the approach used n the algorithm.

• 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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.211-218
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• 1998

The demand prediction becomes an essential mean to utilize efficiently finite traffic facilities and to provide the optimized schedules for transportation system. The demand prediction is one of the critical complex management schemes for distibuting resources of transportation service by means of computer system. The construction of a prediction model is based on data granulization, followed by processing the raw input data and evaluating the predicted output values. A large number of economic-social parameters are also to be implemented in conventional prediction models which are only based on a sequence of past data. The proposed prediction models are classified by static and dynamic characteristics and its performances are evaluated utilizing computer simulation.

• 한국도로학회논문집
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• 제16권4호
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• pp.97-110
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• 2014

PURPOSES: This study is to find the substantial shortcomings embedded in the government policies and practical administrative processes associated with the Korean Transportation Database (KTDB) and to propose preliminary approaches to overcome. METHODS: Administrative and socioeconomic issues on inefficiency in public and private investment and redemption was found from the literature review. Through the interview of sets of experts and practitioners, a set of faultiness embodied in the administrative procedure utilizing and managing KTDB was found and analyzed. RESULTS: This study found the erroneous administrative elements categorized into four groups: faulty socioeconomic data supporting local governors's optimistic will yielded overestimation of future traffic demand; faulty data incidentally introduced in KTDB burdened traffic demand analysis; unavoidable misuse of KTDB worsened the unstability of KTDB; and apathy to manage the KTDB data deviated systematic management. The proposed includes the alteration of the administrative and technical systems to overcome those shortcomings. CONCLUSIONS : Erroneous administrative elements associated with KTDB should be concerned prior to indicating subsequential faultiness in demand analysis.

• 디지털융복합연구
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• 제16권5호
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• pp.137-143
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• 2018

우리나라의 항공여객 운송실적은 지속적으로 성장하고 있다. 본 연구에서는 우리나라 항공여객 운송 실적의 성장추이를 확인하기 위해 시스템다이내믹스를 활용한 항공여객 수요예측 모델을 제안하였다. 항공여객 수요예측은 항공여객 운송수요를 종속변수로 하고 국제항공유가, GDP 및 환율을 외생변수로 하여 시뮬레이션 하였다. 모델의 정확도는 MAPE와 $R^2$를 이용하여 검증하였고 검증 결과 제안된 예측모델은 정확한 예측모델로 확인되었다. 수요예측 결과 국적 항공사의 항공여객 처리실적은 앞으로도 지속적으로 성장하며, 특히 저비용항공사의 수송 분담률이 크게 증가할 것으로 예측되었다. 향후 한국에 진출해 있는 외국계 항공사들의 내국인 처리 실적 및 국적항공사들의 Alliance 체결에 따른 실적 등을 추가하여 보다 정확한 항공여객 수요예측 모델을 제안하고자 한다.