• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.4
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• pp.31-43
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• 2019

Take-overs occur in autonomous vehicles at levels 3 and 4 based on SAE. For safe take-over, it is necessary to set the time required for diverse drivers to complete take-over in various road conditions. In this study, take-over time and stabilization characteristics were measured to secure safety of take-over in autonomous vehicle. To this end, a virtual driving simulator was used to set up situations similar to those on real expressways. Fifty drivers with various sexes and ages participated in the experiment where changes in traffic volume and geometry were applied to measure change in takeover time and stabilization characteristics according to various road conditions. Experimental results show that the average take-over time was 2.3 seconds and the standard deviation was 0.1 second. As a result of analysis of stabilization characteristics, there was no difference in take-over stabilization time due to the difference of traffic volume, and there was a significant difference by curvature changes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.17-25
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• 2010

In Korea, the importance of walking has not been stood out in relief because of the rapid increase of a car on a drastic economic growth in the past half a century. Walking has failed to be recognized as a traffic measure or one of basic human rights. Therefore this study brings up problems of weakened walking right from increase of cars and examines reinforcing policies for walking right of advanced countries. And this study presents institutional devices for introducing walking safety measures of advanced countries reflecting pedestrian satisfaction and opinions about walking right. The results of this study are, First, pedestrians' walking liberty is guaranteed, Second, how to repair walking environment is searched and practical measures are analyzed to find out what is applicable to Korea, can reduce pedestrian accidents and is wanted by pedestrians using GAP analysis and Structural Equation. Third, basic data for upcoming selection of policies are presented by analyzing pedestrian satisfaction assuming that selected measures are operated.

• Journal of the Korean Geotechnical Society
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• v.22 no.4
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• pp.5-10
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• 2006

A special finite difference method for nonlinear dynamic response analysis of semi-infinite foundation soil using mapping which transforms semi-infinite domain into finite domain is presented here. For the region of engineering interest, mapping is isometric, and fur far field, shrink mapping which transforms infinite interval into finite interval is adopted. At first, the responses of semi-infinite foundation soil with linear constituting model are computed, and compared with theoretical results and those of existing method. Good agreements are obtained among the results of the proposed method, Lamb's theory and FEM with extensive mesh model. Then the responses of infinite foundation soil are computed by the present method, using small and large mesh model. The results of small and large mesh models agree well with each other, demonstrating the effectiveness of the proposed method.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.159-166
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• 2010

Trip distribution is to connect travel demand for each OD pair based on travel cost, trip production and attraction derived from trip generation step. In real world the travel cost is a function of travel demand, but existing models could not fully consider such functional relation between travel cost and demand, which leads to an equilibrium in trip distribution model. This paper proves the equilibrium trip distribution by using gravity model. In order to obtain such equilibrium this paper also presents a solution algorithm based on fixed point theorem. The algorithm will be tested with an example and confirmed the equilibrium solution of trip distribution.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.57-64
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• 2005

Recently, several national construction projects such as Chunsung Mt. section of Kyungbu High Speed Rail or Sapae Tunnel of Seoul Outer Ring Road have been delayed or suspended due to the objections of residents or environmental organizations. Considering the development of democracy, increased public participation and interests on environmental issues in Korea, the generation of these social conflicts may be natural phenomenon. However, it is necessary to find measures to effectively implement major construction project and save costs related to social conflicts. In this paper, PI techniques in the United States are investigated and in comparison, the weakness and improvement plans for Korea's current public participation system have been suggested.

• Proceedings of the KIEE Conference
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• summer
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• pp.541-544
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• 2004

지난 99년 이후 친환경적이며 경제적이고 효율적인 대체 교통수단의 개발이라는 목표 하에, 차세대 근거리 교통수단으로 각광받고 있는 경량전철 시스템 적용을 목표로 무인 변전소 기반의 전력감시제어 시스템(SCADA)을 개발하였다. 차세대 변전소 기술 적용이라는 취지 하에 각종 IED들과의 연계는 모두 통신으로 처리하여 시스템의 고기능화를 추구하였고, Network 이중화를 통하여 시스템의 신뢰성을 제고하였으며, CCTV 및 각종 보안센서를 적용하여 배전반의 무인화 운전 및 원격 상시 감시 기능을 구현하였다. 이로써 신뢰성 있는 시스템 기반의 무인 변전소 기술 확립이라는 측면에서 현재 진행되고 있는 변전소 자동화 기술에 일조하며, 나아가 향후 에너지 IT산업기술의 기반이 되리라 사료된다.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.163-168
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• 2009

Travel time reduction is a benefit in economic analysis. Freight transportation time reduction benefits influence the logistics industry. The objectives of this paper are to estimate the Value of Time (VOT) for transportation time reduction with logit methodology. The data of Gyeonggi-do's domestic road freight transport in 2007 are used. VOT was estimated for five commodities. An average VOT of 19,946 won/vehicle-hr was calculated; transport of electronic parts had the highest VOT. This study will help provide direction for improving Korea's road infrastructure for freight.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.173-184
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• 2005

Pavement markings delineate driver's sight and attentions at day and night. Retroreflectivities of the pavement markings are known to be affected by some factors such as geometrical characteristics of road sections, marking materials, traffic volumes, weather, and so on. Therefore, pavement markings would have different retroreflectivities place by place. The objective of this paper is to contend that there are rises and falls of retroreflectivity of specific geometrical characteristics of road section based on observed field data. For this purpose, retroreflectivities of yellow continued lines and white skip lines were measured on the freeway sections from Hanam to Nami interchanges. And then, the sections are categorized based on road geometric or facility types. From this study, it may be concluded that there exist considerably lower retroreflectivity trends of pavement markings at sharply curved sections, climbing lane sections, ramp sections, and tunnel sections than averaged retroreflectivity trends on freeway sections. This may leads to the necessity of differential pavement marking managements.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.32-43
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• 2020

The transfer time is an important factor in establishing public transportation planning and policy. Therefore, in this study, the influencing factors of the transfer time for transit users were identified using smart card data, and the estimation results for the transfer time using the deep learning method such as deep neural network models were compared with traditional regression models. First, the intervals and the distance to the bus stop had positive effects on the subway-to-bus transfer time, and the number of bus routes had a negative effect. This also showed that the transfer time is affected by the area in which the subway station exists. Based on the influencing factors of the transfer time, the deep learning models were developed and their estimation results were compared with the regression model. For model performance, the deep learning models were better than those of the regression models. These results can be used as basic data for transfer policies such as the differential application of transit allowance times according to region.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.48-56
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• 2012

One kind of crowdsourcing techniques which allow drivers to collect and provide traffic information using smartphones and applications is being introduced to ITS system as well. The introduction of crowdsourcing techniques requires changes in the existing ITS based on Insourcing which provide traffic information generated by detectors through VMS. ITS Information have had two problems, one is the high cost and the other is an interrupted service. Experts expect crowdsourcing technique which is created SNS, will overcome problems of ITS. But, there are not many examples and research results. Crowdsourcing technique was utilized in Jeju ATMS project to install ITS on the coastal round roads around Jeju since ITS to install point detectors turned out to be non-economic method in case of the coastal round roads with low traffic volume. However, there existed links in which traffic information cannot be generated as there were no smartphone users (crowds) even in the cost-effective crowdsourcing techniques, which indicates the fact that the crowdsourcing method is suitable for urban roads with many smartphone users, but not for local minor roads. On the contrary, insourcing-based ITS is considered to be non-economic method in applying to all roads in the city, but it can be effectively utilized in the local minor roads. Accordingly, Inter-sourcing based ITS operating system in which insourcing is connected with crowdsourcing was suggested in this study.