• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.113-123
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• 2012

This study introduces a new type of a modal split model that use zonal data instead of cost data as independent variables. It has been indicated that the ones using cost data have deficiencies in the multicollinearity of travel time and cost variables and unpredictability of independent variables. The zonal data employed in this study include (1) socioeconomic data, (2) land use data and (3) transportation system data. The test results showed that the proposed modal split model using zonal data performs better than the other does.

• Journal of Korean Society of Transportation
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• v.16 no.1
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• pp.99-110
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• 1998

본 연구에서는 인간의 판단과 유산한 구조를 갖는 퍼지근사추론모형(FARM)을 구축하여 교통수단 선택형태에 적용하고자 하였다. 이를 위해 먼저 근사추론모형의 이론적 배경을 살펴보고 버스와 지하철간의 수단선택 모형을 구축하였다. 입력변수로 버스와 지하철간의 총통행시간의 차이와 총통행비용의 차이를 선정하였으며 출력변수로 버스이용확률을 사용하였다. 각 변수에 대한 퍼지집합은 각각 5개씩의 언어적 인 표현으로 구성하였으며, 규칙은 총 25개로 설정하였다, 구축된모형의 현실적 타당성을 검토하기 위해 서 실제 조사자료와 비교하였다. 분석결과 본 연구에서 구축된 퍼지근사추론모형이 통행자들의 수단선택 행태를 현실적으로 설명하는 것으로 나타났다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1550-1552
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• 2005

본 논문은 건설교통부의 국도 ITS에 도로변의 현장설비와 센터간 교통정보 수집체계에 전력선통신(Power Line Communication, PLC)망 적용에 관한 연구이다. 지능형교통시스템(Intelligent Transport System, ITS)에서 사용하고 있는 기존의 유 무선 통신망과 PLC망과의 통신 용량 및 속도, 구축 및 운영비용, 데이터 신뢰성 등을 비교하여 적용 가능성을 분석하였다.

• Proceedings of the Korean Society for Information Management Conference
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• 2005.08a
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• pp.287-290
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• 2005

국내단행본 디지털화의 비용과 편익을 정량적, 정성적으로 분석하여 디지털화에 소요되는 비용과 편익을 구체화한다. 비용항목으로는 국내단행본 디지털화에 투입되는 정보시스템비, 인건비, 유지보수비, 디지타이징 비용을 측정하며, 편익항목으로는 도서관측면의 대출시간 절감편익, 운영비 절감편익 등으로 산출하며, 이용자측면은 접근편익, 대출시간 절감편익, 교통시간 절감편익 등을 분석하여 경제성을 도출한다.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.227-235
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• 2008

This study analyzed the efficiency of a trunk with branches and a trunk with feeders route system comparing the user cost and operator cost of those route systems. Basically, a trunk with branches is more efficient than a trunk with feeders in the passengers' perspective if the transit system of a trunk and feeders are the same. In the case that the trunk system is hierarchically higher than the feeder system, a trunk with feeders has the competitive edge over a trunk with branches if the saving of travel cost induced by using the trunk line is larger than the increasing waiting and transfer cost. This result is consistent with the previous research by Park et al.(2007c), which analyzed the efficiency of hierarchical structure in a grid transit network. If the travel demand of each origins and destinations is low, increasing headway according to the travel demand can increase passenger load or operating efficiency in a trunk with feeders route system. In this case, a trunk with feeders route system is more prevalent as the operating cost, route length, and number of destinations increases, while it is less prevalent as the transfer cost and passengers' time value of the waiting time increases. In cases that central business district, which is located in the middle of a trunk line, generates travel demand, a trunk with feeders is more efficient than a trunk with branches with the increasing travel demand from and to the CBD. Therefore it can be concluded that to have a dual operating system between CBD and suburban is more efficient than one type transit system. The efficiency of that system can be increased through an efficient transfer system that can reduce the transfer cost.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.111-123
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• 2005

A network design model has been proposed. which represents a transportation facility investment decision problem. The model takes the discrete hi-level programming form in which two types of decision makers, government and travelers, are involved. The model is characterized by its ability to address the total social costs occurring in transportation networks and to estimate the equilibrium link volumes in multi-modal networks. Travel time and volume for each link in the multi-modal network are predicted by a joint modal split/traffic assignment model. An efficient solution algorithm has been developed and an illustrative example has been presented.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.2
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• pp.80-93
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• 2018

Public transit services are generally analyzed based on the correlation of demand and supply. The computation of supply uses accessibility while demand uses travel demands estimation based on residential population. However, the traditional demand estimation has a limitation in analysing in micro-scale compared to the smartcard data traffic. This study analyzed potential improvement of public transit services using smartcard traffic data. The supply of transportation was defined using time distance accessibility. Also, time loss was calculated in those origin destination(OD) pairs where time distance accessibilities are relatively low. The proposed method was applied at Seoul. The results showed that the areas where OD pairs need improvement include Seodaemun-gu, Guro-gu and Nowon-gu.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.89-100
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• 2008

In an urban network controlled by traffic signals, there is an interaction between the signal timing and the routes chosen by individual road users. This study develops a bi level programming model for traffic signal optimization in networks with path based traffic assignment. In the bi level programming model, genetic algorithm approach has been proposed to solve upper level problem for a signalized road network. Path based traffic assignment using column generation technique which is proposed by M.H. Xu, is applied at the lower-level. Genetic Algorithm provieds a feasible set of signal timings within specified lower and upper bounds signal timing variables and feeds into lower level problem. The performance of this model is investigated in numerical experiment in a sample network. In result, optimal signal settings and user equilibrium flows are made.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.147-154
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• 2010

This paper suggests new route plan cost calculation and cost-effective route plan algorithm and architecture for the new city traffic information system when it is operated nationwide. New algorithm and architecture estimates cost with traffic speeds which is supported for all different lanes, stratifies logical layer which process different levels' traffic information with diverse traffic patterns and provides different traffic information in the few levels. Also suggested new algorithm supports drivers' customized traffic information through both-way communications and plans routes effectively based on the distance between drivers' start position and destination and different levels which start and end position located. It proposes additional research items and requirement for integration between different cities' traffic information system which the national police agency invested and led.

• Journal of Navigation and Port Research
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• v.42 no.3
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• pp.187-194
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• 2018

Aids to Navigation (AtoN) is a marine traffic safety facility used to facilitate the safe and efficient movement of shipping and enhance the protection of the marine environment by the regulations or guidelines of The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). Our country is managing AtoN to provide consistent services for AtoN users, although an average of 141 AtoN accidents occur annually. An AtoN accident forces non-planned work on the managers to resort the function, and causes psychological anxiety for its users, ultimately resulting in economic losses. This study developed the Social Cost evaluation model of AtoN accidents. The model can be used to quantify the manager's economic activities related to the shutdown and recovery, as well as the cost associated with the inconvenience to AtoN users. The Social Cost evaluation model of AtoN accidents is proposed as the sum of the encounter cost, administration cost and risk cost.