• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.326-329
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• 2010

현재 시행 중인 승용차 RFID 요일제는 제한적인 설치장소와 RFID 설치시 많은 비용이 소비된다. 따라서 본 연구에서는 기존의 RFID 승용차 요일제 방식과 달리 효율성을 높이고 비용을 절감할수 있는 BMS(BUS Management System)를 활용한 버스 RFID system에 관한 방안을 제안한다. 제안하는 방안은 버스 RFID system은 대구시의 시내 버스 뒤편에 양쪽 상단에 RFID 안테나를 설치하여 대구시의 주요 도로를 운행 하며 승용차 요일제를 미준수 여부를 파악하는 것이다. 기존의 고정형 RFID는 설치 위치를 우회 할수 있지만 버스 RFID는 항상 이동하며 감지 하기때문에 차량의 우회에 따른 미확인 경우를 줄일 수 있다. 또한, BMS 활용으로 설치비용을 절감하여 비용대비 효율성을 제고할 수 있을 것으로 예상된다. 구체적인 방안 마련을 위하여 주요도로 버스노선도 파악, 중첩지점 그리고 기존의 승용차 요일제 시스템과 비교 분석을 하여 성능 평가들 실시하는 것에 주안점을 두고 연구를 수행하였다.

• Journal of Intelligence and Information Systems
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• v.5 no.1
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• pp.81-93
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• 1999

열차운용이라 함은 열차의 출발과 도착 시간을 나타내는 열차번호들에 여러 객차들로 구성된 하나의 열차를 일컫는 열차 다이아(train DIAgram)들을 여러 제약조건을 고려하여 배정함으로서 열차 번호가 열차 다이아에 의해 운행될 수 있도록 열차운용 다이아를 작성하는 작업이다. 이러한 작업을 다수의 스케줄링 전문가들이 스케줄링 할 경우 많은 시간과 노력을 감수해야만 하며, 전문가의 실수로 인해 오류가 발생할 가능성이 있다. 뿐만 아니라, 복잡한 스케줄의 특성상 운용 비용이 적게 드는 스케줄 결과를 이끌어 내기가 어렵다. 본 연구에서는 열차운용 시스템을 구성하기 위해서 현재 철도청에서 사용하는 시스템을 분석하여, 열차운용 스케줄링 시스템을 모델링 하였고, 이에 모델링한 시스템을 바탕으로 CSP(Constraint Satisfaction Problems: 제약조건 만족 문제) 해결 기법을 적용하여 계산시간 및 계산 복잡성 면에서 효율적인 스케줄링을 행함과 동시에 비용 최적 함수를 적용함으로서 열차 운용 비용이 최소가 되는 열차운용 스케줄링 시스템을 구현하였다. 더불어, 시스템모델 검증과정의 하나로 과거 운용되었던 새마을호 열차시간표와 열차 데이터를 사용하여 열차 운용 및 운용 비용의 최적화를 실험하였다.

• Spatial Information Research
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• v.18 no.3
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• pp.63-72
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• 2010

The vehicle routing problem with simultaneous pick-up and delivery (VRPSPD) is a variant of the vehicle routing problem (VRP) that customers require simultaneously a pick-up and delivery service. The main objective of VRPSPD is to minimize a cost of routes satisfying many constraints. Traditional VRPSPD have been dealt with a static environment. The static environment means that a routing data and plan cannot be changed. For example, it is difficult to change a vehicle's routing plan so that a vehicle serves the pick-up demands of new customers during the delivery service. Therefore, traditional approach is not suitable for dynamic environments. To solve this problem, we propose a novel approach for finding efficient routes using a real-time re-routing heuristics based on the Location Based Service (LBS). Our re-routing heuristics can generate a new route for vehicle that satisfies a new customer's demand considering the current geographic location of a vehicle. Experimental results show that our methodology can reduce the traveling cost of vehicles comparing with other previous methods.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.54-63
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• 2017

With the aim of promoting the use of metropolitan railways, the present research developed a mode choice model for evaluating its competitiveness against passenger cars. A case study was carried out with Gyeongeui and Joongang line, and the area of interest was the direct operating railway between Ilsan and Guri station where the two lines intersect. The mode choice model was a disaggregate behavior model which used Stated Preference (SP) survey data, and the plot of competition was between private passenger cars and express trains. As a result, the mode choice model was established, and this model was used to analyze characteristics of passengers' time value and elasticity. It was shown that reducing travel time is more efficient than reducing travel cost when it comes to operating express trains in metropolitan railways. Therefore, policies designed for activating the use of metropolitan railways should expand direct operating service of individual lines and run more express trains in order to minimize transfer and in-vehicle time.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.54-68
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• 2015

The advantage of electric taxies is that people who are not familiar with electric vehicle(EV) can have easily experience to ride EV. So, EV taxi would be a reasonable strategy for triggering EV market expansion. However, the EV taxi can be adopted by taxi companies with financial benefits. Therefore the feasibility study should be required by analyzing the cost with the points of view of the taxi company. In this study we suggested the methodology for feasibility study of the EV taxi based on the real taxi data and presented political implication. According to the study result, EV taxies could have economic value under the specific conditions such that the government subsidy is added to the purchase price of the vehicle. Also, the charging time should be used as drivers' rest time or mealtime in order not to consider the loss cost. We suggest that the new feasibility study which compares an EV taxi with other alternative vehicles such as PHEV or with an old EV taxi is needed as the future works.

• Spatial Information Research
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• v.22 no.5
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• pp.65-75
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• 2014

Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers' waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.115-122
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• 2010

The importance of the life cycle cost (LCC) analysis for bridges has been recognized over the last decade. However, it is difficult to predict LCC precisely since the costs occurring throughout the service life of the bridge depend on various parameters such as design, construction, maintenance, and environmental conditions. This paper presents a methodology for the optimal life cycle cost design of a bridge. Total LCC for the service life is calculated as the sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The optimization method is applied to design of a bridge structure with minimal cost, in which the objective function is set to LCC and constraints are formulated on the basis of Korean Bridge Design Code. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on damage probabilities to consider the uncertainty of load and resistance. Repair and rehabilitation cost is determined using load carrying capacity curves and user cost includes traffic operation costs and time delay costs. The optimal life cycle cost design of a bridge is performed and the effects of parameters are investigated.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1707-1714
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• 2011

Since 2010 December, the Gyeongchun line can provide better service than the other modes in respect of cost & time efficiency by operating electric double track from Sangbong station to Chuncheon station. However customers living in the Northern part of capital area, which there are stations of line No.1, have inconvenience to transfering twice to access Gyeongchun line. To minimize inconvenience, this study has analyzed the demand variation of Geongchun line upon changing the terminal of some trains on Gyeongchun line which reduces the number of transfer. In this study, the demand variation has been estimated by the direct demand model considering only saving time between O/D. So some additional modifications are required, because the effect of fare and accession convenience has not been considered.

• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.358-367
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• 2020

With the increases of average commuting time of office workers in the Seoul metropolitan area and the cost of traffic congestion on roads, the need for new transportation is increasing and urban air mobility (UAM) is emerging as an alternative. Therefore, in this paper, the vertiport locations were selected and routes were established using population, traffic and commuting data of Seoul and Gyeonggi Province. Vector thrust type and multicopter type of eVTOL compatible for UAM were selected by analyzing the types of eVTOLand time required for selected routes was calculated. In addition, the time required when we utilize other transportations was compared with UAM. Finally, it was verified that the commuting time can be sharply reduced when we use UAM.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.4
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• pp.1-6
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• 2004

For a given plant design, improved decisions on when to shutdown an existing plant may be obtained by making better predictions of failure rates, by exerting efforts to collect more relevant information or by improving decision making models which put that information to best use. It is important that the models include the value of possible loss of lives and fear along with cleanup, decommissioning, relocation if the decisions derived from the model are to be useful. The decision model we have described enables us to investigate a class of optimal decisions on whether to shutdown or continue operating one period of time. The analysis and decision process is repeated at the end of each period with additional information about new costs and risks.