• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.31-40
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• 1998

본 연구의 목적은 기존의 Cell Transmission(1994, Daganzo) 교통류 이론을 기반으로 동적통행배정 모형을 개발하는 것이다. 이 모형은 동적 O-D 발생모듈, HOV 차선모듈, 분류부 분할모델, 링크비용함수 모듈, 최단경로 탐색 모듈등으로 구성된다. 이 모델에서 적용하는 교통류 모델은 각 링크를 동일한 특성을 가지는 셀로 구분하여 셀내의 진입시간과 진출시간을 계산하여 링크비용을 계산하는데 이것은 비용의 과대·과소 추정을 피할 수 있으며 교통지체 현상을 현실적으로 표현해 줄 수 있는 장점이 있다. 또한 HOV 차선 모듈에 의해 수단별 교통류 진행 및 비용고려가 가능하며 HOV 차선의 평가 및 분석이 가능하다. 기존의 동적통행배정모형은 매 시간대별 출발지에서 균형상태를 추구하는 통행배정기법을 사용하고 있지만 이 모델은 분류되는 노드를 가상의 출발점이라고 가정하여 각 시간대별로 최단경로를 탐색하여 균형상태를 추구해나가는 기법을 적용하고 있다. 각 셀별 차량을 목적지별, 차종별, 대기시간별로 추적하여 진행시키며 분류부에서는 최단경로를 탐색하여 배분된다. 또한 진행하고자 하는 셀의 용량과 현재 셀의 밀도를 고려함으로서 용량제약 하에서의 동적통행배정모형을 적용하고 있다. 이 모형은 고속로의 합류부 및 분류부의 교통특성을 세밀히 분석할 수 있으며, TCS 및 램프미터링과 접목하여 고속도로 운영에 이용될 수 있으며, 고속도로 중·장기적인 계획에 이용될 수 있다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.14-27
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• 2020

Pedestrian deaths account for a high percentage of deaths in traffic accidents in Korea, raising interest in pedestrian safety policy. However, since the walk signal time is applied based on the length of the crosswalk without considering the walker and the signal cycle, the walk waiting time is relatively longer than the crosswalk, causing pedestrian jaywalking. In this study, due to an unreasonable signal time plan during a road crossing where a signal is installed, the pedestrian's walk signal was given twice a cycle of crossings, and the operational and safety effects of the signal system were quantitatively and qualitatively analyzed, and the operational effects of the signal interval and jaywalking rate were assessed by different signal intervals. The results showed that jaywalking and waiting time decreased, and the shorter the interval between the application of the walk signal time, the less jaywalking is analyzed. However, there is a risk of vehicle conflict due to pedestrian exposure, and measures for expanding safety for operation were proposed.

• Journal of Korean Society of Transportation
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• v.33 no.1
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• pp.1-13
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• 2015

This study aims to develop a mainline metering strategy considering queue imbalance among lanes that can reduce congestion at a toll plaza section by managing queue caused by mainline metering. The suggested strategy considers simultaneously optimizing the number of cars in merging area and managing queue by lane. This study analyzes the effectiveness of the strategy with respect to the average travel time and the occurrence rate of spillback using the PARAMICS. The results show that the suggested strategy has an effect on reducing congestion and improving operation efficiency at toll plaza. In particular, the congestion become more intensified when the length of waiting space is shorter; however, this study shows that the suggested strategy can relieve the congestion in that condition.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.177-191
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• 2021

One of the major causes of serious air pollution worldwide is emissions from road transportation. A number of countries are working to reduce vehicle emissions, and the Seoul Metropolitan Government is also implementing active policies to reduce emissions by setting a target of 40% by 2030. Implementing these policies requires the introduction of practical indicators. Most of the domestic emissions are calculated by the emission coefficient, a function of speed at the National Institute of Environmental Research under the Ministry of Environment, but the dynamic variable speed is limited to being used as an indicator of the number of eco-friendly vehicles. Therefore, this study calculated the emission rates in Seoul using the vehicle registration data of Seoul and the vehicle inspection data from the Korea Transportation Safety Authority. The tendency of emissions was determined according to key variables such as vehicle type, fuel and mileage. Emissions were based on carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter measured by vehicle inspection from the Korea Transportation Safety Authority. As a result, the emission rates showed a significant trend according to the model year and mileage. This can be used as a policy indicator to preferentially switch commercial vehicles with old model years and long mileage when switching eco-friendly vehicles in Seoul.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.56-61
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• 2011

For the prevention of air pollution, the CNG vehicles have been supplied since 2006. The spread of CNG vehicles has decreased the level of air pollution. Declared goals of Korean Ministry of Environment (ME) are to supply CNG city bus by 90% by 2012. CNG bus explosion has exacerbated commuters' safety concerns, it has caused the barrier to the installation of CNG station. In this study, the sensor was installed for the safety improvement of CNG station. When new sensors were installed, a problem was encountered by a line of communication. To solve the installation problem, we carried out the monitoring of data communication network by USN technology.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.108-117
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• 2011

Seoul metropolitan government has been operating traffic signal control system with the name of COSMOS since 2001. COSMOS uses the degrees of saturation and congestion which are calculated by installing loop detectors. At present, inductive loop detector is generally used for detecting vehicles but it is inconvenient and costly for maintenance since it is buried on the road. In addition, the estimated queue length might be influenced in case of error occurred in measuring speed, because it only uses the speed of vehicles passing by the detector. A traffic signal control algorithm which enables smooth traffic flow at intersection is proposed. The proposed algorithm assigns vehicles to the group of each lane and calculates traffic volume and congestion degree using traffic information of each group using VANETs(Vehicular Ad-hoc Networks) inter-vehicle communication. It does not demand additional devices installation such as cameras, sensors or image processing units. In this paper, the algorithm we suggest is verified for AJWT(Average Junction Waiting Time) and TQL(Total Queue Length) under single intersection model based on GLD(Green Light District) Simulator. And the result is better than Random control method and Best first control method. In case real-time control method with VANETs is generalized, this research that suggests the technology of traffic control in signalized intersections using wireless communication will be highly useful.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.193-206
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• 2002

A signal optimization model is proposed by applying the Cell-Transmission Model(CTM) as an embedded traffic flow model to estimate a system-optimal signal timing plan in a transportation network composed of signalized intersections. Beyond the existing signal-optimization models, the CTM provides appropriate theoretical and practical backgrounds to simulate oversaturation phenomena such as shockwave, queue length, and spillback. The model is formulated on the Mixed-Integer Programming(MIP) theory. The proposed model implies a system-optimal in a sense that traffic demand and signal system cooperate to minimize the traffic network cost: the demand departing from origins through route choice behavior until arriving at destinations and the signal system by calculating optimal signal timings considering the movement of these demand. The potential of model's practical application is demonstrated through a comparison study of two signal control strategies: optimal and fixed signal controls.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.573-582
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• 2014

Since there is no clear installation criteria on minimum spacing between signalized intersection and minor road, many problems have occurred in terms of traffic operation and safety. Even though many studies about entrance/exit intersection have been done in operational aspects, there is no specific and detailed research between the signalized intersection and minor road by now. Thus, this research suggests the optimal spacing between signalized intersection and minor road considering traffic operation and safety. Also, survey on vehicle behavior was conducted in this research. In conclusion, by suggesting the required minimum spacing between signalized intersection and minor road, it can be contribute in establishing and operating the installation criteria between signalized intersection and minor road.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.101-113
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• 2001

Since late 1970s. one of the principal research areas in transportation problem is dynamic traffic assignment (DTA). Although many models have been developed regarding DTA, yet they have some limits of describing real traffic patterns. This reason comes from the fact that DTA model has the time varying constraints such as state equation, flow propagation constraint, first in first out(FIFO) rule and queuing evolution. Thus, DTA model should be designed to satisfy these constraints as well as dynamic route choice condition, dynamic user equilibrium. In this respect, link-based DTA models have difficulty in satisfying such constraints because they have to satisfy the constraints for each link, while path-based DTA models may easily satisfy them. In this paper we develop a path-based DTA model. The model includes point queue theory to describe the queue evolution and simulation loading method for depicting traffic patterns in more detail. From a numerical test, the model shows promising results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.117-118
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• 2019

부산항만은 년간 천만 TEU 이상의 환적 물돌량을 처리하는 세계 2위 환적항이다. 이러한 환적 물량을 효과적으로 처리하기 위해서는 선사, 운송사, 트럭, 터미널 등 각 이해관계자간 정보의 신속하고 정확한 전달이 중요하나, 현재는 정보전달 방법이 다양하고, 정보 공유가 미흡하여 차량 대기, 정보의 누락, 터미널 혼잡 등 문제가 발생하고 있다. 이를 해결하기 위해 부산항만공사는 블록체인 기술을 활용하여 이해관계자 간에 정보를 실시간 공유함으로써 작업 우선순위를 고려한 운송계획 등을 수립할 수 있도록 하여 운송 효율을 높이기 위한 노력을 하고 있다. 본 사례 발표에서는 부산항의 ITT 관련 문제점 및 개선 방안, 향후 계획 등에 대해 논의하고자 한다.