• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.56-73
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• 2019

Probe-based systems have been gaining popularity in advanced traveler information systems. However, the high possibility of providing inaccurate travel-time information due to the inherent time-lag phenomenon is still an important issue to be resolved. To mitigate the time-lag problem, different prediction techniques have been applied, but the techniques are generally regarded as less effective for travel times with high variability. For this reason, current 5-min aggregated data have been commonly used for real-time travel-time provision on highways with high travel-time fluctuation. However, the 5-min aggregation interval itself can further increase the time-lags in the real-time travel-time information equivalent to 5 minutes. In this study, a new scheme that uses both individual probe and 5-min aggregated travel times is suggested to provide reliable real-time travel-time information. The scheme utilizes individual probe data under congested conditions and 5-min aggregated data under uncongested conditions, respectively. As a result of an evaluation with field data, the proposed scheme showed the best performance, with a maximum reduction in travel-time error of 18%.

• Journal of Environmental Impact Assessment
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• v.20 no.2
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• pp.217-226
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• 2011

This paper was inspired by the fact that Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic jam information in real-time basis. Emission characteristics of experimental engines were studied with variable travel distances and speed of car in terms of traffic information provided. 12 Km distance road of Susung district in Daegu is taken as an experimental area to examine this new approach. The emission was tested while the driving was done at 8 AM, 3 PM, 6 PM which represents various traffic conditions. The reduced emission has been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and various loads (CO, VOC and NOx) are all inventoried and calculated in terms of existing emission factors. The emission has been shown to reduce linearly with travel distance : carbon monoxide (20.56%), VOC (29.21%), NOx(8.86%).

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.159-167
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• 2013

PURPOSES : In this study, the effects of when median exclusive bus lanes were applied to Daejeon trunk road (Wolpyeng crossway~Seodaejeon crossway, 6.3km) and (Daeduck Bridge 4~Kyeryong 4, 2.6km) by Microscopic Simulation VISSIM (5.0) was studied. The median exclusive bus lanes are one of the measures of transportation system manage techniques that can especially improve the efficiency of public transportation facilities. METHODS : According to the analysis of VISSIM on the Gyerong mainroad and Daedeok mainroad, when the median exclusive bus lanes were applied unlike when the roadside bus-only lanes were applied, the average travel speed of vehicles decreased but the average delay time and travel time increased. This arised from the changes in the geometric structure of the road which occurred the reduction of vehicle lane in the center of the road. RESULTS : In the case of bus, on the other hand, the average travel speed increased but the average delay time and travel time decreased. This is because the problems such as illegal parking and stopping, secondary road in out vehicle, and conflict of intersection right turn that roadside bus-only lanes occurred was solved. CONCLUSIONS : Although the introduction of median exclusive bus lanes will have a negative effect on general traffic flow due to the aggravation of travel, decrease of passenger car usage will lead to decrease of traffic volume. Therefore, smooth vehicle travel is expected.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.465-473
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• 2005

In the analysis of the foreign cases on the use of Transit Signal Priority(TSP), the reduction in bus travel time ranged from 6 to $32\%$. This study demonstrates how TSP can be applied to Ulsan Metropolitan City. TSP techniques were used on the bus routes that run eastward for 4.07 kilometers along Munsoo-Ro, a major artery in the most congested part of the city. The simulation was performed on one hour of peak traffic time, using the two TSP strategies of Early Green and Extended Green. The use of the Early Green strategy resulted in an average decrease in travel time ranging from 18.1 to $25.8\%$ and an increase in average travel speed ranging from 30.9 to $40.1\%$. The Extended Green strategy resulted in an average decrease in travel time ranging from 18.1 to $30.3\%$ and an increase in an average travel speed of approximately $30.1\%$. This study demonstrates that TSP is effective in decreasing travel time and increasing travel speed of the bus system in Korea.

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.97-116
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• 1999

The growing demand for the real time traffic information is bringing about the category and number of traffic collection mechanism in the era of ITS. There are, however, two problems in making data into information using various traffic data. First, the information making process of making data into the representative information, for each traffic collection mechanism, for the specified analysis periods is required. Second, the integration process of fusing each representative information into "the information" for each link out of each source is also required. That is, both data reduction and/or data to information process and information fusion are required. This article is focusing on the development of information fusing algorithm based on voting technique, fuzzy regression, and, Bayesian pooling technique for estimating the dynamic link travel time of networks. The proposed algorithm has been validated using the field experiment data out of GPS probes and detectors over the roadways and the estimated link travel time from the algorithm is proved to be more useful than the mere arithmetic mean from each traffic source.

• Journal of Korean Society of Transportation
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• v.35 no.6
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• pp.481-498
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• 2017

Travel time reduction benefit is the most important benefit item in the feasibility study of transportation infrastructure investment projects and calculated by using the value of travel time. The current feasibility study guideline (5th edition) calculate the value of non-business ravel time in a metropolitan area, using the ratio of the value of non-business travel time to business travel time calculated based on the nationwide inter-regional traffic survey data of 1999. The characteristics of metropolitan trips are different from those of nationwide regional trips. Metropolitan trips have frequent transfers between multiple public transits and long-time commuter trips. Therefore, this research aims to calculate the value of travel time reflecting traffic characteristics in a metropolitan area by improving the limitation of current calculation methods. To reflect these characteristics, this research extracts commuter trips from non-business trips and calculates the value of travel time for commuter trips. The results of the likelihood ratio test for the commuter trip model and the non-business trip model are found to be statistically significant. An integrated public transportation model was also estimated in this study to reflect the trip conditions of the Seoul metropolitan area integrated fare system. The results of comparing coefficients between bus and subway in the integrated public transit model indicated that there were no statistically significant differences between the two modes.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.443-453
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• 2011

Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic information in real-time basis. Emission characteristics of test engines were studied in terms of travel distance and speed. The present study focused on a north district in Daegu, 12 km. The driving for the emission test was done at 8AM, 3PM, 7PM which represents various traffic conditions. The reduced emissions of Greenhouse Gases (GHG) have been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and GHG ($CO_2$, $CH_4$, $N_2O$) are all inventoried and calculated in terms of existing emission factors. The emission of GHG has been shown to reduce linearly with travel distance: $CO_2$ (9.15%), $CH_4$ (18.43%), $N_2O$(18.62%).

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.1-7
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• 2018

Gentry is responsible for moving the fine chip in the device that mounts the chip on the PCB. However, it is not easy to increase productivity because of the mechanical limitations of the gantry. Therefore, in this paper, we try to solve the method to increase the productivity by software. For this purpose, we propose a method to improve the productivity by shortening the movement time of the gantry. First, we calculated the total travel time for the current method(stop-motion). In addition, the total travel time is also calculated for the travel time reduction method presented in this paper. This method reduces the travel time by checking parts without stopping in front of the camera. As a result, we showed that the proposed method shortened the time of 16%. In the future, we will study time calculation methods for other types.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.29-38
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• 2006

After the first opening of the KTX in April 2004, travel time between major cities has been dramatically reduced. The reduction rates range from 32% to 47%. Considering travel time reduction between major cities, this study concerned about the intercity travel impact of the KTX operation. This study aimed to analyze intercity mode choice behavior of Daegu Citizens according to the first opening of the KTX. This study takes place in two sections. These are (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. This study estimated empirical models for analyzing intercity mode choice behavior according to the first opening of the KTX. This study makes use of the data from travel survey from Daegu metropolitan area. The main part of the survey was carried out in the KTX Dong-Daegu station. The survey data includes the information on travel from Daegu to Daejeon and from Daegu to Seoul. In order to analyze intercity choice behavior according to the frist opening of the KTX, multinomial model structure is used. For the model specification, a variety of behavioral assumptions about the factors which affect the mode choice, were considered. From the empirical model estimation, it is found that OVTT(Out-of-Vehicle Travel Time), OVTC(Out-of-Vehicle Travel Cost), IVTT(In-Vehicle Travel Time), IVTC(In-Vehicle Travel Cost), travel frequency, travel purpose, sex, age, occupation. household income, individual income are significant in choosing intercity travel mode. However, it is found that the intercity nde choice behavior is different between (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. Furthermore, some policy implications are discussed in conclusion.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.63-70
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• 2000

Light Rail is highlighted for its construction cost and operation ＆ maintenance cost in Korea. However, lack of analysis on driverless operation effect causes many disputes. In this paper, using latest driverless operation cost data. analysed cost reduction effect of it, with comparing present KNR's metropolitan subway signal system. It showed there is enough economic appropriateness B/C 1.241 on interest rate 6%, 1.076 on 8% and 0.943 on 10%, though it couldn't include passenger travel time value.