• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.1-7
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• 2019

Thisstudy presentsthe development of a fast-time airport surface simulator. The simulator usesthe output from a first-come first-served (FCFS) scheduler and has adopted one-dimensional dynamic model to simulate the movement of the aircraft on the surface. Higher collision risks situations in the airport surface traffic are analyzed to classify those situations into six cases. A conflict detection and resolution algorithm is implemented to maintain separation distance and to prevent deadlock. The simulator was tested with a scenario at the Incheon International Airport that contains 72 aircraft. Without the conflict detection and resolution, various conflict situations are identified. When the conflict detection and resolution algorithm is managing the traffic, it is confirmed that the conflicts are removed at the price of additional delays. In the conflict resolution algorithm, three prioritization strategies are implemented, and delayed aircraft count and average additional delays are compared. Prioritization based on remaining time or distance showed smaller total additional delay compared to choosing minimum delay priority for each situation.

• Journal of Korean Society of Transportation
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• v.16 no.4
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• pp.139-152
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• 1998

본 연구에서는 3차원그래픽스를 이용하여 영상검지기에서의 교통정보를 얻기 위한 검지영역 설정시 안정된 검지영역을 찾기 위한 시뮬레이터를 개발하였다. 기존의 영상검지기에서는 사용자가 임의로 검지영역을 설정하여 교통정보를 수집함으로 인하여 안정된 교통정보를 얻기가 어려웠으며, 영상카메라의 설치시 과다한 설치규격의 설정으로 비효율적 측면이 발생될 수 있다. 이러한 단점을 보완하기 위해서는 영상검지기를 현장에 설치하기 전에 영상검지기 설치를 위한 사전 모의실험을 토대로 최적의 안정된 설치위치 결정이 매우 중요하다. 본 연구에서 개발한 모의 실험기는 도로의 기하구조와 차량을 모델화 하고 이를 3차원으로 좌표화하여 좌표변환식과 원근변환식을 이용하여 3차원좌표를 2차원으로 변환시키고 컴퓨터 모니터에 투영하여 대상 설치위치에서의 결과를 가시화하였다. 본 연구는 개발된 모의실험기의 적용성 검토를 위하여 현재 영상검지기를 운영중에 있는 한 접근로를 대상으로 사례연구를 수행하였다. 수행결과 교통량과 통행속도계측시 최적검지영역 설정을 위한 영상검지기의 설치규격은 높이가 각각 7m, 12m이상이며, 수직각은 각각 $30^{\circ}$, $80^{\circ}$인 것으로 나타났다.

• Journal of the Korean Society for Railway
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• v.4 no.2
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• pp.47-54
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• 2001

Railway companies have been faced with many changes in the railway environment. To cope immediately with the influence of environment and to improve productivity, an efficient train operation system and related core technologies must be introduced. The railway system is composed of large scale infrastructures and high-cost trains. Simulation method is one of core technologies and also efficient tool for planning and analyzing these kinds of complex system. In this research, we review basic simulation programming models and present a modeling for the elements of railway system such as rail-line infrastructure, train, time table and operational route. Additionally, some considerations on the development of multi-train traffic simulator for KyongBu-line are discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.47-65
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• 2014

VMS(Variable Message Sign) helps drivers to choose their path to destinations on roadways. Some types of VMS often provide traffic information with clearly visible and comprehensible graphical route diagrams. Currently many diagramed types of VMS are installed on urban arterial and highways. This type of VMS surely enhances drivers' ability to comprehend traffic route information while they are driving on the roadway. Nevertheless, some of them are presented with so much information and design elements and they sometimes lead to decline of drivers' comprehensible level for traffic information. Drivers would fail to decide their preferable route in this state of information overflow. The purpose of this paper is to develop a drivers preference model for effective design principle including size and height of displaying font, and the amount of information in the route diagram considering driving speed, sex and age of the driver. This model is developed using structural equation modeling techniques. This model considers driver's emotional factor and, human factor and design component of route diagram. To collect data, we built driving simulator which is able to replicate real driving condition. 72 people who participated in the simulation were selected considering gender and age. The developed model showed that the amount of information, and visibility are more influential factors to the drivers' preference of the route diagram on VMS than design elements such as the shape and the font of the diagram.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.44-53
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• 2016

The era of Big Data has come and the importance of Big Data has been rapidly growing. The part of transportation, the Four-Step Travel Demand Model(FSTDM), a traditional Trip-Based Model(TBM) reaches its limit. In recent years, a traffic demand forecasting method using the Activity-Based Model(ABM) emerged as a new paradigm. Given that transportation means the spatial movement of people and goods in a certain period of time, transportation could be very closely associated with spatial data. So, I mined Spatial Big Data from SNS. After that, I analyzed the character of these data from SNS and test the reliability of the data through compared with the attributes of TBM. Finally, I built a database from SNS for the operation of ABM and manipulate an ABM simulator, then I consider the result. Through this research, I was successfully able to create a spatial database from SNS and I found possibilities to overcome technical limitations on using Spatial Big Data in the transportation planning process. Moreover, it was an opportunity to seek ways of further research development.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.478-487
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• 2015

This study proposed a Variable Speed Limits(VSL) algorithm to use traffic information based on Cumulative Demand-Capacity Analysis and evaluated its performance. According to the analysis result, the total of delay consisted of 3 separate parts. There was no change in total travel time although the total of delay decreased. These effects was analysed theoretically and then, evaluated through VISSIM, a microscopic simulator. VISSIM simulation results show almost same as those of theoretical analysis. Furthermore in SSAM analysis with VISSIM simulation log, the number of high risk collisions decreased 36.0 %. However, the total delay decrease effect is not real meaning of decrease effect because the drivers' desired speed is same whether the VSL model is operated or not. Nevertheless this VSL model maintains free flow speed for longer and increases the cycle of traffic speed fluctuation. In other words, this is decrease of delay occurrence and scale. The decrease of speed gap between upstream and downstream stabilizes the traffic flow and leads decrease number of high risk collision. In conclusion, we can expect increase of safety through total delay minimization according to this VSL model.

• Annual Conference of KIPS
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• 2016.04a
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• pp.443-446
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• 2016

차량의 증가에 따라 다양한 교통문제들이 발생하고 있다. 이러한 문제를 해결하고자 IT기술과 융합된 지능형 교통시스템(ITS)의 연구가 진행되고 있다. 하지만 기존 ITS기술들은 국가별로 도로의 특성이 다양하기 때문에 쉽게 적용하기 어렵다. 그러므로 기존ITS기술들을 실험 및 테스트하기 위한 시뮬레이션 환경이 필요하다. 본 논문에서는 ITS기술들을 한국도로에 적용 할 수 있도록 하는 교정방법을 제안한다. 실험 도로는 항상 정체 현상이 발생하는 서울외곽순환고속도로를 선택하였고 실험 환경은 PTV사의 VISSIM 시뮬레이터를 이용하였다. 실험 결과 실제 속도 등고선 그래프와 시뮬레이션 환경에서의 속도 등고선 그래프의 병목현상이 발생하는 구간이 동일한 것을 확인 하였다. 또한 스테이션별 통행량 그래프를 비교하여 실제 교통량과 유사함을 확인하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.1-11
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• 2010

Traffic broadcasting is using a usual traffic information announcement when giving its information to users on the road and for the provision of information useful to drivers, a clear criteria of how to judge with information from informers needs to be established from the perspective of users. In this study, to give some available criteria for current announcement which often causes confusion, cognitive characteristics were investigated and analyzed based on judgment criteria which are commonly felt by correspondents, participants in traffic broadcasting and drivers. The result requires the provision of information that is relied on an average speed where drivers feel little cognitive difference and found a classification where a smooth traffic flow is more than 60km/h, going slow 40~60km/h and congested state less than 40km/h respectively. And from the study of 35 traffic information announcement for different traffic situations, 8 cases of smooth state and 9 cases of congested state were clearly classified but the rest 18 cases of comment were ambiguously perceived by drivers and which requires the necessity of a announcement that uses directly the word of 'smooth', 'slow', and 'congestion' in the actual expression of slow driving. The future study should be focused on the establishment of more definite criteria by representation of nearly real traffic flow, provision of traffic information announcement and the analysis of cognitive response through car dynamic simulators and the kinds.

• Journal of Korean Society of Transportation
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• v.33 no.1
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• pp.70-80
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• 2015

In recent years, tram has been the focus of a new mode of public transportation that can solve traffic jams and decrease public transit usage and environmental problem. This research is in the works to develop a tram signal controller and signal control strategies, and aim to resolve the problem of what could happen if a tram system was installed in general road. We developed the hierarchical signal control strategies to obtain a minimum tram bandwidth and to minimize vehicle delay, in order to perform a priority control to include passive and active signal priority control strategies. The strategies was produced for S/W and H/W, it is based in standard traffic signal controller. We conducted a micro simulation test to evaluate the hierarchical signal control strategies, which showed that the developed optimization model is effective to prevent a tram's stop in intersection, to reduce a tram's travel time and vehicle's delay.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.69-76
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• 2015

Although traffic information has been actively analyzed using big data, it has not been used as much with the consideration of driver characteristics. Among the various types of information, road signs can directly affect the driver. Road signs must provide the optimal information that enables drivers to reach their destinations with ease as well as information suitable for navigation systems. However, present road sign rules provide standardized information, regardless of the road type or size. This study suggests a method for providing road information that will help drivers determine their behavior. First, the minimum character size that can be used on a road sign for each design speed was obtained with respect to the visibility and decipherability of a road sign. Instead of conventional diagram-based direction guidance, a scenario using split-based direction guidance was created. To verify the effectiveness of the provided information, a three-dimensional simulated road environment was constructed, and a driving simulator was used for the test. At a simple plane intersection, the driver was not greatly influenced by directional guidance, but at a complex, three-dimensional intersection, the driver preferred summary-based directional guidance, which is instinctive guidance, over diagram-based guidance. On the basis of the test results, a secondary verification test that applied split-based guidance at a three-dimensional intersection confirmed that the driver had no problems in making decisions.