• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.4
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• pp.168-174
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• 2005

In this study, the numerical simulation of drying processes for porous materials is performed by employing the hierarchical multi-scale modeling and the nano-scale material properties obtained from the molecular dynamics simulation. The multi-scale simulation system is set up using pre- and post-processors and the drying process of electric porous ceramic insulator is simulated. The temperature, moisture, residual stress, and displacement distributions are compared with those based on homogenized properties.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.83-94
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• 2003

Many cities, recently, have convertedoptimized fixed-time control to adaptive traffic system in the control of their signalized traffic network. The expected benefit from the adaptive traffic system is its ability to constantly modify signal timing to most effectively accommodate changed traffic conditions. While the potential benefits from this control structure may be significant, few studies have compared the effect of implementing this method of signal control against other alternative signal control strategies, because it is too difficult to evaluate the efficiency of the real-time adaptive system. The objectives of this research are : to develop a microscopic simulator and to compare the effect at isolated intersections, corridors, and networks between the fixed signal timing plan and adaptive traffic signal system. This simulator will have allowed more sophisticated analysis techniques for the study of traffic control. Also, this research using this simulator evaluated a real-time traffic responsive signal system used in Seoul Korea

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4975-4983
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• 2010

In this paper, the ordinariest and strongest simulator that many used to power electronics circuits and many different control technology can apply to more easily understand modeling the element, PSPICE and MATLAB are adapted a micro IGBT, a macro IGBT, PWM generator and to library moeling of validity of the Induction motor is interpreted. Micro IGBT model of demagnetization quality proved for modeling accuracy to through experiment, macromodel IGBT were simulated which the applied to voltage type PWM inverter to the cyclo-converter and induction motor of demagnetization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.251-259
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• 2013

This paper is aimed to introduce to a moving bollard (i.e., smart bollard) to improve the pedestrian safety along the crosswalk in the school zone as a means to physically separate pedestrians and approaching vehicles, to propose the appropriate criteria for its installation and implementation from the traffic engineering perspective, and to evaluate its effectiveness with the microscopic simulation model. The simulation results indicate that implementing the smart bollard results in the decrease of average approaching speed and traffic throughput and the most critical factors affecting its effectiveness are yellow time of the traffic signal directly associated with the location of the advance warning sign and its operation time, 5~6 seconds and 2~3 seconds, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.243-250
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• 2014

Modern roundabouts referred to as relatively safer and more efficient traffic facility than the signalized intersections have been recently deployed and operated and accordingly more research efforts to improve its safety and efficiency have been made so far. This paper introduces a new traffic information system named as Smart Roundabout coupled with Connected Vehicle technique like Vehicle-to-Roadside communication, which has not been attempted before and evaluates its performance with a microscopic simulation model, VISSIM. The proposed system functions to collect driving information of circulating vehicles in the roundabout such as location, speed, critical headway, etc. and help approaching vehicles decide whether to enter the roundabout with an on-board equipment instrumented in the individual vehicle on the basis of calculated gap acceptance of interest. This new system is expected to secure more safety and increase the capacity of the modern roundabout.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.499-509
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• 2016

The pedestrian traffic flow has more complicated microscopic features than vehicular traffic flow. Without any designated lanes or any guidance, pedestrians naturally move and change their routes in two dimensional domain with ease. Thus the assessment of pedestrian comfort level should be considering the microscopic features of pedestrian flow. This study is aimed at developing pedestrian comfort criteria based upon pedestrian flow simulation model. This study suggests three criteria to determine pedestrian comfort level; the deviation of route, the acceleration of walk, and the number of collision. Each criterion, which can address the unique walking patterns of pedestrian flow, is represented as each different function with respect to traffic flow rate. The criteria can be the additional indicators to determine the level of service of pedestrian flow together with traffic flow rate and walking speed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.26-37
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• 2009

This paper suggests a sensor's placement method for detecting the dilemma zone problem when real-time driver's safety service is provided at signalized intersections by multiple pointed traffic sensors using USN environments. For detecting the dangerous situations from vehicles accelerating through yellow intervals, red-light running and stopping abruptly like as dilemma zone problem, VISSIM(microscopic, behavior-based multi-purpose traffic simulation program) is used to perform a real-time multiple detection situation by changing the input data like as various inflow-volume, design speed change, driver perception and response time. As a result, the optimal interval of traffic sensors is 20~27m, and the initialized sensor location from stop-line is different according to road design speed. Moreover, the pattern of detection about dilemma zone is also different according to inflow-volumes. This paper shows that the method is useful to evaluate the sensor's placement problem based on micro-simulation and the results can be used as the basic research for USN services.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.14-28
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• 2018

Thanks to technical improvement on the vehicle to vehicle communication and the intelligent transportation system, gradual introduction of the autonomous vehicles is expected soon in the market. The study analyzes the autonomous vehicles' impacts on the network efficiencies. In order to measure the network efficiencies, the study applies the sequential procedures that combines the microscopic and macroscopic simulations. The microscopic simulation attends to the capacity changes due to the autonomous vehicles' proportions on the roadway while the macroscopic simulation utilizes the simulation results in order to identify the network-wide improvement. As expected, the autonomous vehicles efficiently utilizes the existing capacity of the roadway than the human driving does. Particularly, the maximum capacity improvements are expected by the 190.5% on the expressway. The significant capacity change is observed when the autonomous vehicles' proportions are about 80% or more. These improvements are translated into the macroscopic model, which also yields overall network efficiency improvement by the autonomous vehicles' penetration. However, the study identifies that the market debut of the autonomous vehicles does not promise the free flow condition, which implies the possible needs of the system optimal routing scheme for the era of the autonomous vehicles.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.32-39
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• 2010

수도권의 도시화 과정은 서울로의 교통 접근성의 변화에 따라 급속하게 확산되었고, 현재도 진행 중이다. 도시화 과정 속에 인구 교외화, 주택 수의 증가, 도심용지 토지이용 증대, 토지가격의 증가 등의 다양한 공간적 변화가 이루어지고 있다. 이러한 급속한 도시화의 과정 속에 국토의 난개발이 이루어졌고 자연생태 파괴, 주택부족 및 교통 문제, 토지 투기 등의 사회적 문제를 야기했다. 본 연구에서는 도시화 현황을 살펴보고 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하였다 상관성 분석 결과를 토대로 멀티 에이전트 시스템(MAS)을 이용하여 교통접근성과 토지이용 에이전트 간 상호작용의 관점에서 시뮬레이션 하였다. 그래서 교통접근성의 변화로 인한 주변 토지 이용 변화를 공간적으로 예측하려고 한다. 도시화 현황을 살펴보기 위해서 지적도 자료를 이용하여 미시적인 경관 분석을 실시한 후 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하기 위해 교통자료와 토지이용 자료를 GIS분석 및 통계 분석하였다. 그리고 상관성 분석 결과를 멀티 에이전트 시스템 전용 플랫폼에 적용하여 시뮬레이션 분석을 하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.33-43
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• 2013

Comparing to the constant-increasing number of vehicles, road facilities supply such as road construction has already reached the uppermost limit. As one of the most serious issues that the public would personally deal with every day, such is some road traffic problem to be solved instantly. Median exclusive bus lane is now being conducted as a way to enhance efficiency of the public transportation system in Transportation System Management, and with a main arterial that connects Kyeryong-ro (Wolpyeong 3~West Daejeon 4, 6.3km) and Daedeok-daero (Daedeok Bridge 4~Kyeryong 4, 2.6km) in Daejeon adopted as a research target, the study analyzed effects of the arterial by VISSIM the microsimulation. During the analysis, the study focused on figuring out effects of owner-drivers' transport mode choice to take a bus a public transit. According to the simulation results, as people take a bus at the median exclusive bus lane not crb bus lane, traffic for general vehicles has been negatively effected with less drive ways for the vehicles. However, when it comes to the bus traffic, the new transport mode choice appeared to have a quite positive influence after all. A binary logit model analysis reported that owner-drivers might take a bus more often when they earn lower incomes, when they do not travel far, when poor parking is expected and lastly, when they are familiar with using the median exclusive bus lane.