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Kim J.-Y.,Korea Transportation Safety Authority | Kim J.-T.,Korea National University of Transportation | Kim W.,Chungnam Development Institute
Canadian Journal of Civil Engineering | Year: 2015

This paper addresses drivers’ psycho-physiological condition under the influence of various freeway section types and elapsed driving times. The authors analyzed the electroencephalogram (EEG) signals (a, b, and q) of 51 drivers on a freeway in Korea. The findings show that the driver’s workload increases in tunnels and on left-curved sections, and that his or her concentration and response ability decrease after 60 min of elapsed driving time. The b/a ratios of EEG signals were found to be most effective in detecting differences in psycho-physiological responses. The results can help to promote safety on freeways by encouraging drivers to take rests every hour. © 2015, National Research Council of Canada, All Rights Reserved.

Kim M.-J.,Pohang University of Science and Technology | Lim C.-H.,Pohang University of Science and Technology | Lim C.-H.,University of California at Merced | Lee C.-H.,Pohang University of Science and Technology | And 3 more authors.
Lecture Notes in Business Information Processing | Year: 2016

Various types and massive amounts of data are collected in multiple industries. The proliferation of data provides numerous opportunities to improve existing services and develop new ones. Although data utilization contributes to advancing service, studies on the design of new service concepts using data are rare. The present study proposes a data-driven approach to designing new service concepts. The proposed approach is aimed at helping service designers to understand customer behaviors and contexts through data analysis and then generate new service concepts efficiently on the basis of such understanding. A case using bus driving data is introduced to illustrate the process of the proposed approach. The proposed approach provides a basis for the systematic design of new service concepts by enabling efficient data analysis. It also holds the potential to create a synergetic effect if incorporated into existing approaches to designing new service concepts. © Springer International Publishing Switzerland 2016.

Kwon B.-S.,Seoul National University | Kim S.,Korea Transportation Safety Authority | Yi K.,Seoul National University
IEEE Intelligent Vehicles Symposium, Proceedings | Year: 2015

This paper describes a robust yaw stability control for commercial vehicles. In the case of commercial vehicles, parameter variations are relatively large, compared to those of passenger vehicles, due to large variations of load conditions. A feasible parameter variation region can be constructed by Monte Carlo method. The parameter variations in commercial vehicles can cause performance deterioration of a yaw stability controller, designed with nominal parameters. To guarantee the robust performance for a yaw stability controller against parameter variations, it is necessary to design a robust one. To design a robust yaw stability controller, the methods of stochastic root locus and parameter sensitivity reduction are adopted. Computer simulation study was conducted to evaluate the proposed controller. From simulation study, it is shown that the proposed robust yaw stability controller is effective against parameter variations in commercial vehicles. © 2015 IEEE.

Kim T.,Seoul National University | Lee J.,Korea Transportation Safety Authority | Yi K.,Seoul National University
IEEE Intelligent Vehicles Symposium, Proceedings | Year: 2015

This paper presents the maximum tire-road friction coefficient estimation algorithm which considers about the effect of states. Tire force information is an important factor for active safety system. However, it is difficult to estimate due to the dependency on many states such as vehicle speed, tire pressure, and tire wear. In this paper, several experimental researches about the effect of states on the maximum friction coefficient and previous maximum tire-road friction coefficient estimation algorithms are reviewed and summarized. The influential states and the estimation method which doesn't require extra sensors were determined and combined. The proposed algorithm consists of two parts: an interacting multiple models (IMM) based maximum tire-road friction coefficient estimation and an updating sequence based on the effect of vehicle speed. To validate the algorithm, the closed-loop simulation with the advanced emergency braking system (AEBS) has been conducted. It has been shown that the proposed estimation algorithm could enhance the performance of AEBS algorithm. © 2015 IEEE.

Choe B.,Korea Transportation Safety Authority | Lee H.,Korea Transportation Safety Authority
17th ITS World Congress | Year: 2010

The objective of this study is to suggest a process and method of local accident investigation by means of the Transport Safety information Management and Analytical Processing, for short TSMAP. With a project city ANSAN, it will give an overview on automatic mapping accident-types, constructing accident lists, making accident diagrams, prioritizing hot-spots/-lengths, for the sake of helping local authorities inspect high-risk sections and tracking road safety performance in more effective way.

Kim J.Y.,Korea Transportation Safety Authority | Bae J.C.,Korea Transportation Safety Authority | Shin K.Y.,Korea Transportation Safety Authority
17th ITS World Congress | Year: 2010

Korea Transportation Safety Authority(KOTSA) revealed its Intelligent Information System(ITS) Service plans aimed at public transport information and provide of ITS information contents; real time road speed, bus information system and so on. Its public transport information service called ALGOGA system. ALGOGA means that public user could know the route plan and the mode to the destination before the departure. The number of visitor in ALOGGA web page was over twenty thousand ones a day. ALGOGA provides public transport information about timetables, bus stops, subway and route guide as start-destination by three method; personal digital assistants (PDA), internet website and mobile phone. This internet website also offers real-time information on the public traffic situation and alternative recommendations. Recently, an important rise of CO2 emissions is stated due to the circulation of private vehicles. The idea of going Green, ALGOGA provided information of carbon dioxide emission content by using public transport route. The content show carbon dioxide emission to web user in kilogram and the number of tree planted using internet browser popup page. For example, internet users could find the various methods to get their destination in using various public modes and know the number of carbon dioxide emission. And we also provide the exact the number of trees when you use the public mode instead of private one.

Ko J.,The Seoul Institute | Shim J.-S.,Korea Transportation Safety Authority
International Journal of Sustainable Transportation | Year: 2016

As climate change and severe air pollution become life-threatening, numerous attempts have been made to encourage the use of electric vehicles as alternative fuel vehicles. One such proposal is the introduction of electric taxis supported by the battery exchange station (BES) system. This article presents the framework on how the BESs should be located in a city considering the demand and practical constraints using Seoul, South Korea, as the case study. As a solution approach, p-median models are applied for 25 candidate locations and modeling results are presented and interpreted. © 2016 Taylor & Francis Group, LLC.

Lim K.-K.,Korea Transportation Safety Authority
KSCE Journal of Civil Engineering | Year: 2015

Predicting the vehicle used for individual trips and tours can help improve the quantification of energy consumption, quality of emissions forecasts, and assess impacts of policies that vary by vehicle type. The focus of this study is to contribute to incorporating this aspect within current activity-based modeling frameworks. Data from the 2009 National Household Travel Survey of the United States are used in this analysis. The empirical scope of this study is limited to two-adult two car households in the context of social-recreational tours; however, this methodology can be directly extended to other cases as well. An exploratory analysis indicates that the “primary driver” variable is perhaps the strongest predictor of the vehicle allocated to independent tours and tours made by adults with children. In the case of joint tours, there is clearly a choice of vehicle to be made. Following the exploratory analysis, two models were developed. One allocates each vehicle to a primary driver in the household (long-term, household-level model). The second allocates a vehicle for the joint tours (short-term, tour-level model). Both models were estimated using the unlabeled binary-logit methodology. Several vehicle attributes (such as size/body type, fuel efficiency, age, and operating costs) and socio-economic variables (age, and presence of children) were estimated to be statistically-significant predicators of the vehicle-allocation patterns. © 2015 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg

Chung E.K.,Baekseok University | Choe B.,Korea Transportation Safety Authority | Lee J.E.,Yonsei University | Lee J.I.,Yonsei University | Sohn Y.W.,Yonsei University
Accident Analysis and Prevention | Year: 2014

An adult passenger has been known to facilitate young drivers' safe driving. This study examined whether the adult passenger's effect is produced by the simple presence of an adult passenger or by the driving tips offered by the passenger. Further, we examined whether the effect would be transferred to when a young driver drives alone without the adult passenger in the following session. Three groups of participants drove on expressway in a driving simulator, either alone, with a silent adult passenger, or with an adult passenger who gave advice on driving safety. After a break, participants in all three conditions drove on the same expressway alone. Results showed that participants who drove with an adult passenger providing driving tips drove more safely than the other groups, and the effect was transferred to even when they drove alone afterwards. © 2014 Elsevier Ltd.

Lim K.-K.,Korea Transportation Safety Authority
KSCE Journal of Civil Engineering | Year: 2015

Household members often interact with each other during their daily activity- and travel-related decision-making process. In the context of social and recreational activities, these interactions lead to decisions about pursuing such episodes either independently or jointly with others. The substantial focus of the study is on the operationalizing household interactions in various modeling mechanisms by the ways of seeking to maximize the utility of each household member in an interdependent fashion. Florida add-on samples from the 2009 National Household Travel Survey are utilized. The results indicate that household income, age of male, engagement of mandatory activities, engagement of maintenance activities, day of the week, and whether raining have strong impacts on the choice of social-recreational activity participations. Overall, no one model turned out to be a clear “winner” in terms of statistical goodness of fit and predictive abilities, rather on the behavioral insights, the multi-linear logit and parallel constrained logit models do highlight differences in the “power” across household heads, and the trivariate binary probitmodels capture strong correlations in the choices across the male and female and between solo and joint choices. © 2015, Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.

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