• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.99-108
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• 2010

In this study, the characteristics of flow within and around a crossroad connected symmetrically with four roads are numerically analyzed by using a two-dimensional well-balanced HLLC finite volume model. As results of simulations and analyses, the numerical model employed in this study describes relatively well the complex water surface in a crossroad according to the conditions of inflow and road slope. Moreover, the predicted temporal and spatial variations of water depths in a crossroad and outflows at two downstream boundaries agree relatively well with laboratory measurements.

• The KIPS Transactions:PartB
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• v.18B no.3
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• pp.117-130
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• 2011

The purpose of this study is to produce a better way to detect crossroad accidents, which involves an efficient method to produce background images in consideration of object movement and preserve/demonstrate the candidate accident region. One of the prior studies proposed an employment of traffic signal interval within crossroad to detect accidents on crossroad, but it may cause a failure to detect unwanted accidents if any object is covered on an accident site. This study adopted inverse perspective mapping to control the scale of object, and proposed different ways such as producing robust background images enough to resist surrounding noise, generating candidate accident regions through information on object movement, and by using edge information to preserve and delete the candidate accident region. In order to measure the performance of proposed algorithm, a variety of traffic images were saved and used for experiment (e.g. recorded images on rush hours via DVR installed on crossroad, different accident images recorded in day and night rainy days, and recorded images including surrounding noise of lighting and shades). As a result, it was found that there were all 20 experiment cases of accident detected and actual effective rate of accident detection amounted to 76.9% on average. In addition, the image processing rate ranged from 10~14 frame/sec depending on the area of detection region. Thus, it is concluded that there will be no problem in real-time image processing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.119-121
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• 2022

In this paper, we will make a model that finds optimal phase for each crossroad. When the traffic volume, traffic capacity, and the lane width of every direction is given for each crossroad, we aim to find the most efficient phase. We established an evaluation function that evaluates the efficiency of each phase using the values of the average waiting time in one direction, the average delay time, the standard deviation of the delay time, and the average delay time in each direction. The time allocation to optimize a phase pattern can be obtained by using the gradient decent method. Through this research, we hope to decrease the waiting time in transporation, thus improving the overall traffic condition in cities.

• Transportation Technology and Policy
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• v.8 no.4
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• pp.29-33
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• 2011

• The Korean Journal of Air & Space Law and Policy
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• v.6
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• pp.43-83
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• 1994

• The Korean Journal of Ecology
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• v.16 no.2
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• pp.199-208
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• 1993

To estimate the level of the air pollution in Taejon city, the contents of S, Pb and Cd of the leaves of the roadside trees were deterimined. And we analyzed the relationship between the contents of S, Pb and Cd in the leaves of the roadside trees and traffic volume. The ranges of S, Pb and Cd contents in all the samples were 1.82~4.34 mg/g, 1.95~$246.80{\mu}g/g$ and 2.00~$20.50{\mu}g/g$ respectively. Areas with the high contents of S, Pb and Cd in the leaves were the road from Taejon railroad station to the provincial government, West Taejon crossroad, Taehwa-dong, Kasuwon-dong and Yongmun crossroad.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.1 no.1
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• pp.1-5
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• 2001

In this paper, we propose a fuzzy traffic controller that is able to cope with traffic congestion appropriately. In order to consider such situation as loss of green time caused by spillback of upper crossroad, it imports a degree of traffic congestion of upper roads which vehicles on a crossroad are to proceed to. We constructed the equal-partitioned fuzzy traffic controller that uses the membership functions of the same size and shape, and modified the size and shape, and modified the size and shape of its membership functions by the membership function modification algorithm. In experiment, we compared and analyzed the fixed signal controller, the fuzzy traffic controller with the membership of the same size and shape, and the modified fuzzy traffic controller by using the delay time, the proportion of entered vehicles to occurred vehicles and the proportion of passed vehicles to entered vehicles. As a result of experiment, the modified fuzzy controller showed more enhanced performance than others.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2430-2436
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• 2013

This study suggests a method of detecting the still object, which becomes a cause of danger within the crossroad. The Inverse Perspective Transform was performed in order to make the object size consistent by being inputted the real-time image from CCTV that is installed within the crossroad. It established the detection area in the image with the perspective transform and generated the adaptative background image with the use of the moving information on object. The detection of the stop object was detected the candidate region of the stop object by using the background-image differential method. To grasp the appearance of truth on the detected candidate region, a method is proposed that uses the gradient information on image and EHD(Edge Histogram Descriptor). To examine performance of the suggested algorithm, it experimented by storing the images in the commuting time and the daytime through DVR, which is installed on the cross street. As a result of experiment, it could efficiently detect the stop vehicle within the detection region inside the crossroad. The processing speed is shown in 13~18 frame per second according to the area of the detection region, thereby being judged to likely have no problem about the real-time processing.

• Journal of Korea Spatial Information System Society
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• v.10 no.2
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• pp.13-24
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• 2008

A next generation video based car navigation is researched to supplement the drawbacks of existed 2D based navigation and to provide the various services for safety driving. The components of this navigation system could be a load object database, identification module for load lines, and crossroad identification module, etc. In this paper, we proposed the traffic lights and road sign recognition method which can be effectively exploited for crossroad recognition in video-based car navigation systems. The method uses object color information and other spatial features in the video image. The results show average 90% recognition rate from 30m to 60m distance for traffic lights and 97% at 40-90m distance for load sign. The algorithm also achieves 46msec/frame processing time which also indicates the appropriateness of the algorithm in real-time processing.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.570-576
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• 2012

In this research a moving platform for a mobile robot which can run with upright posture is proposed. It is able to stand with standing arms and run uprightly based on an inverted pendulum mechanism. Conventional mobile robots generally may equip 4 wheels or 3 wheels including a caster and have good statistic stability. They need a steering mechanism to choose which way to go since they have a square or rectangular configuration with multiple wheels. When a mobile robot meets a sharply perpendicular and narrow crossroad, it may need a special steering scheme such as going forward and backward repeatedly or it sometimes cannot even pass through the crossroad because of its size. The proposed moving platform for a mobile robot changes to a upright posture which has a small planar area and is able to pass through the crossroad. We propose a moving platform for a mobile robot with a inverted pendulum mechanism and standing arms which can make the mobile robot upright.