• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.45-59
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• 2013

This study deals with the comparative analysis between two freight demand estimation methods : Unimodal O/D based method and P/C based method. The data of access/egress truck trips has been omitted from the Korean freight unimodal O/D of KTDB. This is because KTDB's unimodal O/D has not marked the series of unlinked trips down as the whole freight intermodal transport and surveyed only the main-haul trips of them. For these reasons, freight intermodal transport mechanism has not been analysed perfectly with Korean unimodal O/D data. This study tries to estimate P/C table of Korean Import/Export container freight and develop the MCC(Multimodal Channel Choice) model. Then, comparing unimodal O/D based method and P/C based method in terms of the switch commodities between production point(the initial point of freight transport) and consumption point(the terminal point of freight transport), unimodal commodities, and commodities on links is conducted. The results show that the P/C based method is able to simulate the freight intermodal transport.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2122-2136
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• 2010

Existing model formula in the 4 phase model is limited in the estimation of the demand for urban railway because the administrative region-based formula reflects no spatial characteristics of station surrounding area(SSA) that urban railway forms. The purpose of this study is both to analyse the behavior in selecting the method regarding spatial range of SSA and to do the basic research for the development of new model through the survey conducted in the stations of the metropolitan area. This study will review the domestic and foreign cases about designation of SSA, study the spatial range of SSA through case studies, analyze the selection of methods by the spatial range and estimate the demand of the station on the basis of social and economic indices regarding SSA. This study focuses on the verification of real results and model estimates, due to the time constraint and lack of resources for collecting and analysing the data. According to this study, 500m,1000m division of SSA shows the closest results of the model estimates to the real demand of the targeted stations.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.59-70
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• 2012

The relative importance of leisure trip has been increased after adopting the five-day workweek system and considering the higher income level. Thus, the value of travel time for intercity leisure trips should be estimated to conduct a reasonable benefit/cost analysis for railway construction projects. In this paper, the value of travel time was estimated separately for each trip purpose such as business, leisure, and other non-business than leisure. The estimated values of leisure travel time ranged from 5,310 to 14,185 (won/hr) by altering travel mode, and were increased by 42-107% when comparing with those of non-business travel time. Besides, how to apply the value of intercity leisure travel time for B/C analysis of railway projects was suggested. For the construction case of a railway connecting Chuncheon and Sokcho, the estimated benefit was increased by 2.3%.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.33-43
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• 2013

Comparing to the constant-increasing number of vehicles, road facilities supply such as road construction has already reached the uppermost limit. As one of the most serious issues that the public would personally deal with every day, such is some road traffic problem to be solved instantly. Median exclusive bus lane is now being conducted as a way to enhance efficiency of the public transportation system in Transportation System Management, and with a main arterial that connects Kyeryong-ro (Wolpyeong 3~West Daejeon 4, 6.3km) and Daedeok-daero (Daedeok Bridge 4~Kyeryong 4, 2.6km) in Daejeon adopted as a research target, the study analyzed effects of the arterial by VISSIM the microsimulation. During the analysis, the study focused on figuring out effects of owner-drivers' transport mode choice to take a bus a public transit. According to the simulation results, as people take a bus at the median exclusive bus lane not crb bus lane, traffic for general vehicles has been negatively effected with less drive ways for the vehicles. However, when it comes to the bus traffic, the new transport mode choice appeared to have a quite positive influence after all. A binary logit model analysis reported that owner-drivers might take a bus more often when they earn lower incomes, when they do not travel far, when poor parking is expected and lastly, when they are familiar with using the median exclusive bus lane.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.205-211
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• 2009

There is need to reform the road-based logistic transportation system into the railway-based logistics transportation system in order to decrease the total social cost related with logistics transportation. And new transportation modes such as dual mode trailer (DMT) are under consideration, which are expected to decrease current market share of road. But, most of current studies about estimating economical efficiency are focused on developing the probabilistic choice model and then estimating the market share of each mode. We present an approach to compute the optimal market share of each mode in terms of total social cost. To do so, we suggest an optimization model capturing both user choice to maximize his utility and subsidy policy intended to minimize total social cost, simultaneously. Using this model, we present the optimal modal split of container freight.

• Proceedings of the KOR-KST Conference
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• 2001.02a
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• pp.3-29
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• 2001

본 연구에서는 기존의 대중교통 통행배정모형이 고려하지 않거나 미흡하게 반영하였던 차량과 노선의 용량제약을 고려한 모형의 구축을 시도하였다. 일반적으로 대중교통 통행배정에서 수요와 공급의 관계는 수요가 증가하는 것과 무관하다고 받아들여지고 있으나 용량 초과는 통행자들의 경로선택 및 수단선택에 영향을 끼친다고 볼 수 있다. 이러한 용량초과에 의한 혼잡을 반영하기 위해 용량제약식을 포함한 모형을 개발하고 실용운행회수라는 개념을 도입하였다. 또한 기존에 제시된 용량제약을 고려한 모형들이 실제적인 현상을 정확히 모사하는 데에는 한계가 있을 뿐 만 아니라 현실과 다소 거리가 있는 가정이 내재되어 있는 반면 본 연구에서는 가능한 한 최대로 현실 여건을 반영하는 모형을 정립하였다. 본 연구에서 제시한 모형은 동일한 기종점 사이를 운행하는 경쟁노선이 많은 대도시에서 통근·통학을 위한 통행자들이 많은 오전, 오후 첨두시 대중교통 수요를 분석하여 대중교통의 운행관리체계 개선 및 투자계획, 서비스 개선을 위한 수요예측을 하는데 유용하게 사용할 수 있을 것으로 사료된다. 그리고 기존의 대중교통 통행배정의 결과가 현재나 장래의 잠재적인 수요(demand)를 예측하는 방법인데 반하여 본 연구에서 정립된 모형은 주어진 네트워크에서 실제로 통행하고 있는 수요(flow)를 예측함으로써 교통 계획가나 대중교통 운영자의 계획 및 운영정책수립에 합리적인 도움을 줄 수 있다. 또한 현재의 대중교통 시스템 하에서의 통행배정 뿐만 아니라 다른 형태의 용량과 운행특성을 가진 교통 수단이나 노선이 도입되었을 때 공급이 제한적인 경우의 수요 예측에 적합한 모형을 개발하였다.에 대한 규제가 초국가적 차원으로 발전되는 계기를 제공하고 있다. 향후, 담배규제협약안의 세부사안들에 대한 합의과정에서 각 국별로 상당한 이견과 반발이 예상되고 있지만, 협약안의 전체 회원국 투표에서 승인될 경우 각 국가들뿐만 아니라 담배산업과 담배기업들에게 미치는 파급효과가 매우 클 것으로 예상된다. 대부분의 국제협약들이 그러하듯이, 담배규제협약도 그 적용 범위와 수준이 어느 정도로 결정되는지에 따라 각 국가와 기업별 이해관계가 크게 달라지게 되기 때문에 신중한 대응전략이 요구된다고 하겠다.의 화물전용차선의 설치시는 수답렬 교통량의 구성비와 구간 평균교통량에 의하여 그 효과가 다르게 나타남을 알 수 있었다. 따라서 물류비용 절감차원에서의 화물전용차선의 설치는 본 연구에서 나타낸 방법과 같이 수단간의 경제적 편익을 고려한 구간별 시간대별 효과분석을 통하여 정책의 시행여부가 결정되어야 할 것이다. 한편, 화물전용차선의 설치로 인한 물류비용의 절감을 보다 효과적으로 달성하기 위해서는 종합류류 전산망의 시급한 구축과 함께 화물차의 적재율을 높이고 공차율을 낮출 수 있는 운송체계의 수립이 필요한 것으로 판단된다. 그라나 이러한 화물전용차선의 효과는 단기적인 치유책일 수밖에 없기 때문에 물류유통 시설의 확충을 위한 사회간접자본의 구축을 서둘러 시행하여야 할 것이다.으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군

• Journal of Korean Society of Transportation
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• v.15 no.1
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• pp.63-83
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• 1997

수송비와 재고관리비는 총 물류비용의 50% 이상을 차지할 정도로 그 중요성이 크 며, 이들 두 요소는 상호 정밀하게 관련되어 있어서 비용 트레이드 오프 관계가 존재한다. 이러한 관점에서 제품을 수송하는데 소요되는 총비용을 도출하고 비용이 최소가 되는 수송 수단을 선택할 수 있다. 이같은 분석은 수요와 리드타임이 불확실한 경우 수송시간, 고객 서비스 수준, 안전재고 수준, 주문량, 물류비용 등의 관계가 복잡해지기 때문에 해를 구하는 과정이 복잡하게 된다. 따라서 리드타임 동안의 수요를 나타내는 방법과 수송 시간의 신뢰 도와 관련된 안전재고 측정 및 기준에 대한 다양한 방법이 재고이론에 근거한 화물수송수단 선택모형 연구의 주 관심사가 된다. 본 연구는 국외에서 발표된 관련 연구들을 중심으로 재 고와 수송의 상관관계에 대하여 이론적으로 고찰하여 연구 현황을 밝히고 앞으로의 연구 방 향을 제시함으로써 이 분야의 이론적인 발전에 기여하는 것을 목적으로 한다. 연구의 주안 점은 확률적 리드타임과 수요에 대한 연구에서 쟁점이 되는 리드 타임 동안의 수요를 나타 내는 방법과 안전재고를 결정하는 기준에 모아진다.

• Journal of Korean Society of Transportation
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• v.29 no.1
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• pp.81-93
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• 2011

This research deals with the multi-modal continuous network design problem to resolve the transportation policy problems for constructing and operating transportation facilities with considering the mutual decision-making process between transportation operator and user in the multi-modal network. Particularly, in the consideration of changes in travel pattern between transport modes due to the changes in transportation policy, road network for passenger car and transit network for public transportation are considered together. In the development of network design model, more rational Stackelberg equilibrium(cooperative game) rather than more general Nash equilibrium(non-cooperative game) approach is used and sensitivity analysis considering transport mode is used. A multi-modal continuous network design model in this study is developed for the arbitrary continuous network design parameters(${\epsilon},\hat{\epsilon},p$) of transportation policy decisions. As examples of application and evaluation for these design parameters, the developed model is applied to calculate 1)the optimal capacity of road link in the road transport policy, 2)the optimal frequency of transit line in public transport policy and 3)the optimal modal split in transport modal share policy.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.213-226
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• 2005

Adverse selection is a heavily scrutinized subject within the financial intermediary industry. Consensus is reached regarding its effect on the loan interest rate. Despite the similar features of financial service offered by the credit card, we still have controversy regarding credit card interest rate on how is adverse selection incurred with the change of interest rate. Thus, this paper explores how does the adverse selection, if ever, take place and affect the credit card interest rate. Information asymmetry regarding the credit card users' type represented by the default probability is assumed. The users are assumed to be rational in that they want to minimize the per unit dollar expense associated with the commercial transaction and financing between the two typical payment methods, cash and credit card. Suppliers, i.e. credit card companies, would like to maximize their profit and would be better off with more pervasive use of credit cards over the cash. Then we could show that the increasing credit card interest rate is subject to the adverse selection, sharing the same tenet with that of the bank loan interest rate proposed by Stiglitz and Weiss. Hence the current theory predicts that credit card market also suffers from adverse selection with increasing interest rate.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.45-56
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• 2007

As function and scale of the transit center get larger, the efficient guidance system in the transit center is essential for transit users in order to find their efficient routes. Although there are several studies concerning optimal path for the road, but insufficient studies are executed about optimal path inside the building. Thus, this study is to develop the algorithm about optimal path for car owner from the basement parking lot to user's destination in the transfer station. Based on Dijkstra algorithm which calculate horizontal distance, several factors such as fatigue, freshness, preference, and required time in using moving devices are objectively computed through rank-sum and arithmetic-sum method. Moreover, optimal public transportation is provided for transferrer in the transfer station by Neuro-Fuzzy model which is reflected on people's tendency about public transportation mode choice. Lastly, some scenarios demonstrate the efficiency of optimal path algorithm for pedestrian in this study. As a result of verification the case through the model developed in this study is 75 % more effective in the scenario reflected on different vertical distance, and $24.5\;{\sim}\;107.7\;%$ more effective in the scenario considering different horizontal distance, respectively.