• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.70-86
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• 2022

An autonomous demand-responsive bus with mobility-on-demand service is an innovative transport compensating for the disadvantages of an autonomous bus and a demand-responsive bus with mobility-on-demand service. However, less attention has been paid to the quantitative impact assessment of the autonomous demand-responsive bus due to the technological complexity of the autonomous demand-responsive bus. This study simulates autonomous demand-responsive bus trips by reinforcement learning on a microscopic traffic simulation to quantify the impact of the autonomous demand-responsive bus. The Chungju campus of the Korea National University of Transportation is selected as a testbed. Simulation results show that the introduction of the autonomous demand-responsive bus can reduce the wait time of passengers, average control delay, and increase the traffic speed compared to the results with fixed route bus service. This study contributes to the quantitative evaluation of the autonomous demand-responsive bus.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.163-171
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• 2012

Demand Responsive Transit (DRT) services are becoming necessary as part of not only alternative transportation means for elderly and mobility impaired passengers, but also sustainable and flexible transportation options in urban area due to the development of communication technologies and Location Based Services (LBS). It is difficult to investigate the system performance regarding vehicle operational schemes and vehicle routing algorithms due to the lack of commercial software to support door-to-door vehicle simulation for larger area. This study proposes a simulation framework to evaluate innovative and flexible transit systems focusing on various vehicle routing algorithms, which describes data-type requirements for simulating door-to-door service on demand. A simulation framework is applied to compare two vehicle dispatch algorithms, Nearest Vehicle Dispatch (NVD) and Insertion Heuristic (IH) for real-time shared-taxi service in Seoul. System productivity and efficiency of the shared-taxi service are investigated, comparing to the conventional taxi system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.571-577
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• 2012

Recently, improving public transport service at disabled people has emerged as a social issue in rural areas. By improving expensive and inefficient existing operating system, the rural bus have to change a personalized service. Under these circumstances, government and local governments are promoting the introduction of DRT(Demand response transport). DRT system is intended to promote the user's convenience. But, until now, in-depth research on the operating costs for the introduction of DRT is not well known. This study aims to look at changes in number of vehicle and operating costs before and after introduction of DRT. The results are as follows. Even though introducing DRT, total number of vehicles increases because it does not reduce the existing number of vehicles. And this study estimated to about 5 to 12 percent of the increase in the operating cost comparing before introduction of DRT. Therefore, The introduction of DRT in rural areas is a need to set the exact purpose as promote transportation convenience or cost efficiency.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.29-42
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• 2012

Recently, traffic congestion has become serious due to increase of private car usages. Carsharing or other innovative public transportation systems were developed to alleviate traffic congestion and carbon emissions. These measures can make the traffic environment more comfortable, and efficient. Cloud Transportation System (CTS) is a recent carsharing model. User can rent an electronic vehicles with various traffic information through the CTS. In this study, a concept, vision and scenarios of CTS are introduced. And, authors analyzed the location of CTS rental stations and estimated CTS demands. Firstly, we analyze the number of the population, employees, students and traffic volume in study areas. Secondly, the frequency and utilization time are examined. Demand for CTS in each traffic zone was estimated. Lastly, the CTS rental station location is determined based on the analyzed data of the study areas. Evaluation standard of the determined location includes accessibility and density of population. And, the number of vehicles and that of parking zone at the rental station are estimated. The result suggests that Haewoondae Square parking lot would be assigned 11 vehicles and 14.23 parking spaces and that Dongbac parking lot be assigned 7.9 vehicles and 10.29 parking spaces. Further study requires additional real-time data for CTS to increase accuracy of the demand estimation. And network design would be developed for redistribution of vehicles.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.17-34
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• 2022

This paper develops a model for dynamic station assignment to optimize the Demand Responsive Transit (DRT) operation. In the process of optimization, we use the bus travel time as a variable for DRT management. In addition, walking time, waiting time, and delay due to detour to take other passengers (detour time) are added as optimization variables and entered for each DRT passenger. Based on a network around Anaheim, California, reserved origins and destinations of passengers are assigned to each demand responsive bus, using K-means clustering. We create a model for selecting the dynamic station and bus route and use Non-dominated Sorting Genetic Algorithm-III to analyze seven scenarios composed combination of the variables. The result of the study concluded that if the DRT operation is optimized for the DRT management, then the bus travel time and waiting time should be considered in the optimization. Moreover, it was concluded that the bus travel time, walking time, and detour time are required for the passenger.

• The Journal of Aerospace Industry
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• s.70
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• pp.70-93
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• 2008

산업의 고도화에 따라 시간을 절약하고 공간을 활용하기 위한 방법으로서, 보다 큰 항공기, 보다 빠른 항공기에 대한 요구가 꾸준히 제기된다. 최근 불거진 지구온난화에 대한 이슈는 모든 산업의 초점을 친환경으로 돌려고 있어서, 항공기산업의 경우에도 예외 없이 보다 친환경적이고, 연료 효율적인 항공기개발에 집중하고 있다. 또한, 과거에 비해 자유의지가 강조되는 현재에는 보다 이용이 간편한 개인용 항공기의 출현이 요구되고 있어 이 분야에 대한 연구도 활발히 진행 중이다. 이에 따라 많은 국가들이 각각의 요구에 따라 초대형여객기(VLCT), 차세대 초음속여객기(HSCT), 그린항공기, 개인 자가용 항공기(PAV) 등의 형태로 개발을 서두르고 있으며, 일부 분야는 이미 상용화를 눈앞에 두고 있다. 특히 PAV의 수요는 향후에 자동차 시장의 일부를 대체할 것으로 예상되는 만큼 선진국들은 수요자의 요구에 따라 발 빠르게 대응하여 PAV에 대한 투자를 아끼지 않고 있다. 따라서 본 연구에서는 미래형 항공교통수단의 개발전망과 동향을 분석함으로써 앞으로 우리나라 항공기산업의 발전방향에 대한 시사점을 도출하고자 하였다. 특히 틈새 시장으로서의 PAV 분야의 개발동향과 전망을 살펴봄으로써, 동 분야에 대한 연구개발과 투자를 통한 우리나라 항공기산업의 발전기회를 모색해 보고자 하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.3
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• pp.1-11
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• 2023

COVID-19 has caused the dramatic reduction of public transportation demand in Busan Metropolitan City, that is, daily public transportation trips in 2020 dropped by approximately 920,000 trips from 2019 based on the public transportation card data. This study investigated the underlying factors affecting the public transportation demand discrepancy between before and after COVID-19 at the primary administration unit(i.e., Eup, Myeon, Dong) level with Ordered Logistic Regression model. Finding of this study is as follows. The primary administration units characterized with high ratio of welfare recipients, industrial area, and day boarders were heavily dependent on public transit, indicating little change in public transportation demand. On the other hands, the primary administration units which have high ratio of urban rail transit uses experienced significant reduction of public transportation demand. In conclusion, transportation policies taken under emergent situation such as COVID-19 need to take into account the region-based characteristics rather than unilateral ones.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.228-235
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• 2008

새정부 들어 주택의 안정적 공급을 위한 대책을 내놓고 있으나, 주택 수요 공급과 관련된 통계 및 정보의 종합적 관리 체계 미흡으로 주택수급상황을 파악하여 주택수급에 대처하는 주택하위 시장별 대응정보가 미비한 실정이다. 이에 따라 수급상황을 분석 및 제공하기 위한 정보시스템을 구축 "주택 수요"가 있는 곳에 "주택을 공급"하는 정책지원체계가 요구되고 있다. 이를 위해 본 연구는 행정생활권, 광역교통망, 주택사업위치, 공공 민간 사업지구 등의 GIS정보 기반에 주택 수요 공급 통계 및 정보를 분석하여 정책지원 및 대국민 서비스를 하는 정보체계인 주택수급지도(Housing Demand and Supply Mapping Model)의 구축방안을 제시하였다. 연구에서는 주택수급에 필요한 수요현황 및 예측 등 "주택수요정보"에 기초하여 주택건설, 공급, 재고 등의 "주택공급정보"를 분석하여 주택수급지도에 대한 기본설계 방안을 도출하였다. 향후 주택수급지도를 활용하여 주택수급상황을 한눈에 파악하고, 주택수요를 고려한 수요자별 맞춤형 주택공급정책을 수립할 수 있도록 지원함으로써, 지역별, 주택 규모별, 주택유형별, 인구계층별 주택수급 예측에 활용될 수 있을 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.195-206
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• 2023

Most of the Micro-mobility parking in Korea use Dockless system. However, Dockless can result in cluttering, infrastructure deficiencies, and safety challenges as has been observed in cities. It is necessary to introduce a Station Parking system in order to solve the drawbacks of the dockless, but the introduction without engineering has low accessibility and induces side effects. In this study, to decide optimal location about number of the Micro-mobility Station, we has been applied the MCLP model about the coverage range, usage demand, usage time in order to classify the type of Micro-mobility Station. For the MCLP, User Date input to reflect realistic demand in Bundang new town, Korea. The result show that the optimal number of facilities in 400 m was 146, and the coverage ratio was 99.83 %, which was most suitable coverage for solving the parking problem. We also classified the demand into 4 levels and the usage time into 3 levels, and by crossing them, we were able to classify the Parking lot types into 12 types. It is possible to propose strategic policies in the installation and operation of Micro-mobility Parking System.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.22-32
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• 2010

Increasingly advanced Information Technology (IT) has changed the operator so as to create more diversified and advanced traffic information demand. To deal with the changing demand in private sector, a concept of on-demand traffic information has been rapidly introduced. However VMS, a product of the first generation of ITS, which was designed to provide the unspecified individuals during driving the car with the basic level of traffic information by the public failed to actively change itself in such a changing pattern. This study was intended to describe the VMS system (tentatively, FM-VMS) which was further developed to accommodate the needs favoring the sophisticated PDA with the public role of providing the unspecified individuals with the equal information. FM-VMS introduced in this study is the device designed to transmit the voice and message to the drivers through the radio information device mounted on a car. A core technology is, unlike FM-DARC and RDS, the Water Making technology which directly inserts the digital signal into FM frequency in use. It's been currently used for broadcasting and security purpose. A detection rate as a result of testing FM-VMS system using Water Making technology was 90% or more in voice and message within 20m from test VMS. When a public-developed VMS information could be transmitted using FM frequency to the relatively vulnerable users (vulnerable to traffic information) in voice on a real-time basis to provide the regional traffic information, and furthermore, VMS message could be received through radio liquid using FM frequency only, it would obviously bring about the innovation in ITS as well as pave the way for creating the new added value down the road.