• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.169-175
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• 2004

This paper develops a dynamic travel time prediction model for ATIS in a national highway. While there have been many research on travel time prediction, none of them is for national highway in Korea. The study uses AVI data installed on the national highway No.1 with 10km interval for travel time prediction model, and probe vehicle data for evaluating the model. The study area has many access points, so there are many outlying observations in the raw AVI data. Therefore, this study uses the algorithm proposed by the author for removing the outliers, and then Kalman filtering algorithm is applied for the travel time prediction. The prediction model is performed for 5, 10, 15 and 30 minute-aggregating interval and the results are $0.061{\sim}0.066$ for 5, 10 and 15 interval and 0.078 for 30 minute one with a little low performance as MAREs.

• Journal of Korean Society of Transportation
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• v.34 no.1
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• pp.1-14
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• 2016

In the recent years, the internet has become accessible without limitation of time and location to anyone with smartphones. It resulted in more convenient travel information access both on the pre-trip and en-route phase. The main objective of this study is to conduct a stationary test for traffic information web/mobile application access indexes from TCS (Toll Collection System); and analyzing the relationship between the web/mobile application access indexes and actual traffic volume on expressways, in order to analyze searching behavior of expressway related travel information. The key findings of this study are as follows: first, the results of ADF-test and PP-test confirm that the web/mobile application access indexes by time periods satisfy stationary conditions even without log or differential transformation. Second, the Pearson correlation test showed that there is a strong and positive correlation between the web/mobile application access indexes and expressway entry and exit traffic volume. In contrast, truck entry traffic volume from TCS has no significant correlation with the web/mobile application access indexes. Third, the time gap relationship between time-series variables (i.e., concurrent, leading and lagging) was analyzed by cross-correlation tests. The results indicated that the mobile application access leads web access, and the number of mobile application execution is concurrent with all web access indexes. Lastly, there was no web/mobile application access indexes leading expressway entry traffic volumes on expressways, and the highest correlation was observed between webpage view/visitor/new visitor/repeat visitor/application execution counts and expressway entry volume with a lag of one hour. It is expected that specific individual travel behavior can be predicted such as route conversion time and ratio if the data are subdivided by time periods and areas and utilizing traffic information users' location.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.49-60
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• 2014

For the demand analysis of Metropolitan Train Express project, the catchment area of station should be reevaluated considering the journey speed of it. In this paper, we estimated travel mode choice model using stated preference data including Seoul metropolitan express train and compared the parameters of access/egress travel time between existing metro and Seoul metropolitan express train. The parameter of Seoul metropolitan express train is 2.5 times smaller than that of existing metro. Consequently, the catchment area can be expanded in same proportion. It can be concluded that the result of demand forecasting can be increased by 10% accommodating the expanded catchment area.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.69-82
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• 2000

When new subway lines are considered to construct in a large city, there is a need to establish the appropriate transfer systems between subway and other transit modes, so as to increase the use of subway system. In this study, a multi-nominal logit model is developed to analyze the travel characteristics and the mode choice of subway Passengers transferring to and from the buses, minibuses and taxi. These passengers represent a large Portion of transit Passengers in Pusan city It shows that the explanatory variables that affect Passengers\` mode choice are in order of OVIT(Out-of-Vehicle Travel Time), IVTT(In-Vehicle Travel Time), transit fare,. income, gender, and age in modeling. In particular, OVTT is shown to have more significant impact on the mode choice than IYTT due to the fact that transfer trip is involved only in a short distance. Variables associated with the travel costs, however, do have an insignificant impact on the mode choice. It shows that it would be a better Policy to improve the quality of transit service using additional financial resource by increasing transit fare rather than by reducing the fare to increase travel demand. It also shows that value of travel time of OVTT is remarkably higher than that of IVTT and value of travel time of taxi Passengers is much higher than that of minibus Passengers .

• Journal of Service Research and Studies
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• v.9 no.4
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• pp.19-40
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• 2019

Mobility as a Service is a service conception to achieve the intelligent transportation system. Its aims to improve the travel experience. In one platform, it connects various transportation modes to offer service and users only need to pay in one time for the whole travel. But the single MaaS platform easily faces the problems such as low user traffic, low retention rate and the access to markets of the this service is still unfound. From the perspective of bicycle-sharing, this research makes the MaaS concept into bicycle-sharing to build a better service model. The bicycle-sharing combine with the MaaS concept is innovative in business model, travel model and service architecture. In addition, this research also tests users' expectations for service model. The research shows that MaaS-based bicycle-sharing could offer flexible and convenient travel experience in the aspects of combined transportation, travel, transfer and payment, and it also makes it possible to make travel services according to need, and sustainable transport.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.109-120
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• 2006

Since the 1st of July, 2004, the public transport system of the Seoul metropolitan area has been rearranged. In the new system, bus lines are divided into 4 classes-wide area, arterial road, branch, and rotation lines with renewed fare system based on the total distance travelled. Since central control center known as the Bus Management System (BMS) integrates the entire system operation. it now becomes feasible to collect travel information and provide it to the users scientifically and systematically. The Purpose of this study is to forecast transit travel time using real-time traffic data coming from both buses and subway. This is significant contribution since provision of real-time transit information and easy access to it would most likely boost the use of mass transit system, alleviating roadway congestion in the metropolitan area.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1052-1057
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• 2004

Bluetooth technology is essentially a method for wireless connectivity of a diverse set of devices ranging from PDAs, mobile phone, notebook computers, to another equipments, The bluetooth system both point-to point connection and point-to multipoint connection. In point-to multipoint connection, the channel is shared among several bluetooth devices. Two or more devices sharing the same channel form a piconet. There one master device and up to seven active slave devices in a piconet. The radio operates in the unlicensed 2.45GHz ISM band. This allows users who travel world-wide to use bluetooth equipments anywhere. Since the link is based on frequency-hop spread spectrum, multiple channels can exist at the same time. The bluetooth standard ha s been suggested that bluetooth equipments can be used in the short-range, maximum 100 meters. It has been defined that the time takes to setup and establish a bluetooth connection among devices is 10 seconds. It is a long time and may be a cause to lose a chance of finding other non-fixed devices. We propose a routing protocols for scatternets which can be used to control a mobile units(MUs) in this network. The proposed routing protocol is composed of two kinds of bluetooth information, access point(AP) and MU.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.1-19
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• 2023

Bikes have recently emerged as an alternative to carbon neutrality. To understand the demand for public bikes, we endeavored to estimate travel frequency of public bike by considering the intermediate stops. Using the GPS trajectory data of 'Ttareungyi', a public bike service in Seoul, we identified a stay point and estimated travel frequency reflecting population, land use, and physical characteristics. Application of map matching and a stay point detection algorithm revealed that stay point appeared in about 12.1% of the total trips. Compared to a trip without stay point, the trip with stay point has a longer average travel distance and travel time and a higher occurrence rate during off-peak hours. According to visualization analysis, the stay points are mainly found in parks, leisure facilities, and business facilities. To consider the stay point, the unit of analysis was set as a hexagonal grid rather than the existing rental station base. Travel frequency considering the stay point were analyzed using the Zero-Inflated Negative Binomial (ZINB) model. Results of our analysis revealed that the travel frequency were higher in bike infrastructure where the safety of bike users was secured, such as 'Bikepath' and 'Bike and pedestrian path'. Also, public bikes play a role as first & last mile means of access to public transportation. The measure of travel frequency was also observed to increase in life and employment centers. Considering the results of this analysis, securing safety facilities and space for users should be given priority when planning any additional expansion of bike infrastructure. Moreover, there is a necessity to establish a plan to supply bike infrastructure facilities linked to public transportation, especially the subway.

• Journal of Preventive Medicine and Public Health
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• v.54 no.2
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• pp.129-136
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• 2021

Objectives: This study examined demographic factors hampering access to healthcare at hospitals and suggests policy approaches to improve healthcare management in Thailand. Methods: The data for the study were drawn from a health and welfare survey conducted by the National Statistical Office of Thailand in 2017. The population-based health and welfare survey was systematically carried out by skilled interviewers, who polled 21 519 384 individuals. The independent variables related to demographic data (age, sex, religion, marital status, education, occupation, and area of residence), chronic diseases, and health insurance coverage. The dependent variable was the degree of access to healthcare. Multiple logistic regression analysis was subsequently performed on the variables found to be significant in the univariate analysis. Results: Only 2.5% of the population did not visit a hospital when necessary for outpatient-department treatment, hospitalization, or the provision of oral care. The primary reasons people gave for not availing themselves of the services offered by government hospitals when they were ill were-in descending order of frequency-insufficient time to seek care, long hospital queues, travel inconvenience, a lack of hospital beds, unavailability of a dentist, not having someone to accompany them, and being unable to pay for the transportation costs. Multiple logistic regression analysis showed that failure to access the health services provided at hospitals was associated with demographic, educational, occupational, health welfare, and geographic factors. Conclusions: Accessibility depends not only on health and welfare benefit coverage, but also on socioeconomic factors and the degree of convenience associated with visiting a hospital.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.261-265
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• 2005

In this paper, we constructed the infrastructure with wireless LAN and Access Point in the indoor environment and implemented the teleoperation. Wireless LAN based teleoperation system is irregular communication delay according to environment condition and occurrence possibility of blackout is very high. In this paper, In case these problem happened, we measured communication delay time by real time, and did mobile robot to control harmoniously through vision and force reflection information. Also, we present obstacle-avoidance mode that mobile robot can travel without collision using direction information in case communication delay time is large. We proved usefulness of presented algorithm through teleoperation experiment to apply presented algorithm.