• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.14-22
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• 2011

This study is to estimate delay time model of signalized intersection by using travel data of Bus Information System. BIS, which applies the advanced information technology to an existing bus system, has been developing and operating in many cities. However, even though some useful traffic informations have been collected from BIS operation, utilization of real-time data to the traffic operation has not been promoted due to the inhomogeneity of modal speeds. Accordingly, in this study, a fundamental research is performed for traffic controls in urban areas and providing a traffic information throughout a methodology for estimating delay time using the data from BIS was developed. This delay time model setting bus travel time excluding service time of a bus stop as explanatory variables was constructed as a regression model, and the coefficient of determination of a linear regression model most highly appeared as 0.826. As a result of performing T-test with field survey values and model estimation values for verifying constructed models statistically, it was analyzed to be statistically significant in a confidence level of 95%.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.62-73
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• 2022

As the competition among the autonomous vehicle (AV, here after) developers are getting fierce, Korean government has been supporting developers by deregulating safety standards and providing financial subsidies. Recently, some OEMs announced their plans to market Lv3 and Lv4 automated driving systems. However, these market changes raised concern among public road management sectors for monitoring road conditions and alleviating hazardous conditions for AVs and human drivers. In this regards, the authors proposed a methodology for monitoring road infrastructure to identify hazardous factors for AVs and categorizing the hazards based on their level of impact. To evaluate the degrees of the harm on AVs, the authors suggested a methodology for managing road hazard factors based on vehicle performance features including vehicle body, sensors, and algorithms. Furthermore, they proposed a method providing AVs and road management authorities with potential risk information on road by delivering them on the monitoring map with node and link structure.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.2
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• pp.49-57
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• 2015

The purpose of this study is to provide the visual landscape modelling on Josun royal tombs and surrounding. The visual landscape of traditional heritage is illustrated by the main view points of analysis. This analysis examines limited view points and cannot reflect a reality of environments. Nowadays various equipments and methodologies are developed for the visual landscape research. This study used new tools for analysis which are Sketch up (3D simulation) and mini helicopter (UAV). With those tools, this research examines not only view points of the analysis but also axis views and disincentive environments as a complex analysis. First of all, the research examined 3D modelling for the virtual simulation and drew coordinates and routes for the UAV operating. Secondly, UAV followed this routes and took linear and continuous views that are real scenes. As a result, it drew 3D simulation could illustrate and control the changing of environments such as the forest density and seasonal variations. Thus, comparing both of them shows efficiently landscape analysis. Thirdly, the study compared virtual and real landscape. Using this 3D modelling, this paper able to elaborate heritage environment and surrounding which omitted by view point analysis. Although this study has limitation practice and exercise on the field, the results and suggestions contribute to the various historic heritage managements and conservations. Moreover, it helps to explain the complex and dimensional landscape analysis.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.723-733
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• 2005

This paper presents a deadlock avoidance method for AGVs in automated container terminals. For a more efficient use of AGV traveling area, we divided the area into small-sized grids not enough to cover a whole AGV. Our deadlock avoidance method controls AGVs by identifying strongly connected components(SCCs) in a graph derived from the paths of AGVs on the grids. Also in this paper we suggest a route selection scheme which selects a route by predicting and comparing travel times of candidate routes by using a regression formula. Simulation experiments have shown that the proposed method can control AGVs for 48 hours without deadlocks and the count of AGV visits per QC is increased by $2\~10$ an hour.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.87-94
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• 2013

This study estimated the changes in delays and speeds of vehicles in exclusive bus lane and road when the High Occupancy Vehicles(HOV) use the median bus lane. Synchro simulation tool was used to optimize the traffic signal time on the network and VISSIM was applied to simulate various scenarios. Here, drivers behavior parameters in VISSIM was optimized using Simultaneous Perturbation Stochastic Approximation(SPSA) algorithm in order to represent real traffic condition. Based on the simulation results, the delay in Doan daero was decreased when the volume of HOV in current condition runs on the median bus lane, whereas delay in Doan dongro was increased in all scenarios. The changes in bus speed was not sharply decreased for both study sites, even though the number of HOV increased to 10%. Thus, it could be allowed that the HOV use the median bus lane in Doan dongro and Doan daero. Future research tasks include studying about changes in delay when the HOV use the curb bus lane.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.51-65
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• 2018

Intentional aggressive driving (IAD) is defined as a hazardous driving event that the aggressive driver intentionally threatens neighbor drivers with abrupt longitudinal and lateral maneuvering. This study developed a methodology for detecting IAD events based on the analysis of interactions between aggressive driver and normal driver. Three major aggressive events including rear-close following, side-close driving, and sudden deceleration were analyzed to develop the algorithm. Then, driving simulation experiments were conducted using a multi-agent driving simulator to obtain data to be used for the development of the detection algorithm. In order to detect the driver's intention to attack, a relative evaluation index (Erratic Driving Index, EDI) reflecting the driving pattern was derived. The derived IAD event detection algorithm utilizes both the existing absolute detection method and the relative detection method. It is expected that the proposed methodology can be effectively used for detecting IAD events in support of in-vehicle data recorder technology in practice.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.91-104
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• 2022

The operational design domain (ODD) of autonomous vehicles needs to be expanded on highways and urban roads in light of the substantial commercialization of Level 3 autonomous vehicles. Therefore, this study developed a specific infrastructure autonomous vehicle-based cooperative driving service to ensure the driving safety of autonomous vehicles on city roads. The traffic operation efficiency, safety evaluation, and core evaluation indices for each service were selected and analyzed to study the effect of each service. The result of the analysis confirmed that the traffic operation efficiency and safety of autonomous vehicles were improved through the V2X communication-based autonomous cooperative driving service. On the whole, the significance of this study is in deriving the effect of the autonomous cooperative driving service based on V2X communication on urban roads with interrupting traffic flow.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.33-42
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• 2007

This research proposes strategies about providing detour route information and traffic management for flood disasters. Suggested strategies are based on prevention and preparation concepts including prediction, optimization, and simulation in order to minimize damage. Specifically, this study shows the possibility that average travel speed is increased by proper signal progression during downpours or heavy snowfalls. In addition, in order to protect the drivers and vehicles from dangerous situations, this study proposes a route guidance strategy based on variational inequalities such as flooding. However, other roads can have traffic congestion by the suggested strategies. Thus, this study also shows the possibility to solve traffic congestion of other roads in networks with emergency signal modes.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.23-34
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• 2009

In the railroad rolling stock depot, long-term maintenance tasks is done regularly every two or four year basis to maintain the functionality of equipments and rolling stock body or for the repair operation of the heavily damaged rolling stocks by fatal accidents. This paper addresses the computer simulation model building for the rolling stock maintenance shop for the CDC(Commuter Diesel Car) and Generator Car planned to be constructed at Daejon Rolling Stock Depot, which will be moved from Yongsan Rolling Stock Depot. We evaluated the processing capacity of two layout design alternatives based on the maintenance process chart through the developed simulation models. The performance measures are the number of processed cars per year, the cycle time, shop utilization, work in process and the average number waiting car for input. The simulation result shows that one design alternative outperforms another design alternative in every aspect and superior design alternative can process total 340 number of trains per year 15% more than the proposed target within the current average cycle time.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.166-174
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• 2016

In this paper, we developed a mixed-integer linear programming model for transportation planning of athletes in sports events. The transportation planning of athletes involves finding the lowest-cost and fastest-time plan for distributing athletes from multiple accommodation to stadium. The decision variables associate with the number of driving events, and the total transportation cost is the objective function that needs to be minimized. The proposed method uses mixed integer linear programming to solve transportation problem, thus the global optimality is guaranteed. In order to verify the effectiveness of proposed method, we performed simulation and built the sports event management service platform (SEMSP) for transportation planning.