• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.71-78
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• 2018

Transportation is gradually changing into the era of V2X and autonomous cars. Accurate judgement of traffic conditions is an important indicator of route choice or autonomous driving. There are many ways to use probes car such as taxis, as a way to identify accurate traffic conditions. These methods may vary depending on the characteristics of the probe vehicle, and there is a problem with the cost. The V2X vehicle can solve these problems and collect traffic information in real time. If all vehicles are of V2X vehicle, these issues are expected to be resolved briefly. However, if the communication information of a V2X vehicle is represented by a traffic representative in a traffic with only V2X, the traffic information of some V2X vehicles will be able to collect traffic information. To accomplish this, a virtual network and transport were created and various scenarios were performed through SUMO simulations. It has been analyzed that 3-5 % of V2 vehicles are capable of representative the road traffic characteristics. In the future, various follow-up studies are planned.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.627-635
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• 2014

Currently the highest speed limit on the road traffic congestion or because you can not cope with climate change to cause a traffic accident may be a factor. According to the Road Traffic Act as well as 20% to 50% in case of inclement weather, but the driver must slow speed left to the judgment of the difficulties, and to slow the vehicle and the relative velocity between the vehicle does not run longer be a big influence on the environment and safety. Thus, variable speed control for drivers on the road, specify the appropriate maximum speed limit in bad weather It keeps motorists slowed the run rate to prevent accidents or reduce the severity of accident damage is expected to be possible. The purpose of this study is the frequent traffic accidents Continuous Busan (City Freeway) around the variable speed control in the appropriate sections so that it can be done by analyzing the characteristics of traffic accidents were the severity of the accident. Highway and urban environment, the geometry of the structure because it has a lot of Curved planar point compared to wet and dry road surfaces by simulated rain wet had bom the more the speed the greater the risk of an accident was the result. Based on these results, the primary section, first urban highway tunnel, near the lamp, near Toll Plaza, near binary Outlet after considering various factors such as speed reduction is needed in the first period by conducting awareness and recognize the need for the participation of the driver and the future city installation and operation of highways in all sectors is expected to be expanded.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.116-126
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• 2013

Weather factor to affect driver's driving environment are due to changes in weather conditions is caused rainfall, snowfall, fog etc and the reducing of road capacity and because deteriorating weather could be affect the headway and vehicle speed and the decrease in lane caused by an accident occurs that was analyzed that bad weather occur congestion greater than on the clear day. Bad weather to reduce of the driver's visibility was analysed the sensitive to changes in travel speed and traffic accident to appears high characteristics according to weather conditions on the expressway(higher speed) than general road. As a result, visibility have been determined to be important factor in changes of the highway traffic flow characteristics. Therefore, in this study, we selected traffic volume and travle speed that have a major impact on high-speed expressway basic segments as importance effect factor and we selected to subject of analysis among the Metropolitan Expressway that it could be obtained certain level of traffic volume data and we studied the changing of expressway traffic flow due to change visibility after the collecting of meteorological and traffic data. In order to perform this study, data collection and analysis methods were established through the existing literature and we had selected level of visibility of the expressway and we had performed the statistical verification. Finally, we had calculated the rate of change of expressway traffic flow characteristics due to visibility and we had come up with a way to apply at capacity and service level analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.434-442
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• 2018

In this paper, we propose a road lane color recognition method from the image obtained from a driving vehicle. In autonomous vehicle techniques, lane information becomes more important as the level of autonomous driving such as lane departure warning and dynamic lane keeping assistance is increased. In particular the lane color recognition, especially the white and the yellow lanes, is necessary technique because it is directly related to traffic accidents. In this paper, color information of lane and road area is mapped to a 2-dimensional S-color space based on lane detection. And the center of the feature distribution is obtained by using an improved mean-shift algorithm in the S-color space. The lane color is determined by using the distance between the center coordinates of the color features of the left and right lanes and the road area. In various illumination conditions, about 97% color recognition rate is achieved.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.213-220
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• 2016

In order to drive on road safely, the type of road design and construction is basically needed to optimize driver's safety and vehicle performance. Although the heavy traffic highways were built by reflecting these factors, the national highways and local roads have still taken a lot of problems. In this study, we analyzed the behavior characteristics of a vehicle according to the speed variation of the vehicle using the PC-Crash program for the traffic accidents reconfiguration at GULUN interchange located Hongcheon in Gangwon Province. the conditions outlet surface of the road for analysis were dry road surface, wet road surface and icy road surface. As a result, we identified the fact that the friction coefficient of road surface and the speed of vehicle affected to vehicle behavior characteristics of outlet shape in GULUN interchange, and showed the possibility that we can verify a problem about road design through to this simulation in advance.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.19-28
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• 2011

The safety applications based on the IEEE 802.11p, periodically transmit the safety-related information to all surrounding vehicles with high reliability and a strict timeline. However, due to the high vehicle mobility, dynamic network topology and limited network resource, the fixed beacon scheduling scheme excess delay and packet loss due to the channel contention and network congestion. With this motivation, we propose a novel beacon scheduling algorithm referred to as spatial-aware(SA) beacon scheduling based on the spatial context information, dynamically rescheduling the beaconing rate like a TDMA channel access scheme. The proposed SA beacon scheduling algorithm was evaluated using different highway traffic scenarios with both a realistic channel model and 802.11p model in our simulation. The simulation results showed that the performance of our proposed algorithm was better than the fixed scheduling in terms of throughput, channel access delay, and channel load. Also, our proposed algorithm is satisfy the requirements of vehicular safety application.

• Journal of Korean Society of Transportation
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• v.34 no.3
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• pp.263-277
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• 2016

Traffic safety in freeway work zones is of keen interest since both crash frequency and severity are much higher than those in general freeway sections. The lane closure in work zones results in greater work load of drivers due to compulsory lane changes and speed reduction. Therefore, traffic merging control is an effective countermeasure for enhancing work zone safety. This study proposed an integrated framework based on driving and traffic simulations to evaluate traffic merging control methods in terms of traffic safety. In addition to the conventional merging method using the taper, joint merge and chicane-type merge were evaluated by the proposed methodology. Chicane-type merge outperformed other methods under level of service (LOS) A and B. On the other hand, it was identified that joint merge showed the best safety performance under LOS C traffic conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.30-42
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• 2023

Various studies have been conducted using microtraffic simulation (VISSIM) to analyze the safety of traffic flow when introducing autonomous vehicles. However, no studies have analyzed traffic safety in mixed traffic while considering the driving behavior of general vehicles as a parameter in VISSIM. Therefore, the aim of this study was to optimize the input variables of VISSIM for non-autonomous vehicles through genetic algorithms to obtain realistic behavior. A traffic safety analysis was then performed according to the penetration rate of autonomous vehicles. In a 640 meter section of US highway I-101, the number of conflicts was analyzed when the trailing vehicle was a non-autonomous vehicle. The total number of conflicts increased until the proportion of autonomous vehicles exceeded 20%, and the number of conflicts decreased continuously after exceeding 20%. The number of conflicts between non-autonomous vehicles and autonomous vehicles increased with proportions of autonomous vehicles of up to 60%. However, there was a limitation in that the driving behavior of autonomous vehicles was based on the results of the literature and did not represent actual driving behavior. Therefore, for a more accurate analysis, future studies should reflect the actual driving behavior of autonomous vehicles.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.107-116
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• 2002

Crash Cushion is a kind of safety facilities on roadside which acts the role of absorbing impact energy when vehicles are driven out of normal route such as Gore area of freeway off ramp. Criteria for severity index considering accident occurrence possibility are needed to have strong effect on installing the facilities. However, present criteria for establishing crash cushion design do not include such processes. Therefore, the paper presents two kinds of study to develop criteria for severity index. First of all, development of accident forecasting model on freeway off ramp is presented. The module is a relationship between accidents and road environment by negative binomial distribution (NB) which is called to reflect very well quality of accidents at Gore of crash cushion installed freeway Secondly, freeway exiting behavior model is developed because the human factor is the most important one. However, many literatures have shown between road environment and accidents which are more quantitative than human factor. The study supposed advanced process steps on actual freeway and analysed correlation between variables and accidents. The criteria for severity index is presented to determine whether to install or not by benefit cost analysis for each module. The standard for severity index will help to determine whether to install the crash cushion or not and to estimate severity for freeway and off ramp.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.205-209
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• 2008

Recently, for development of hardware systems, it has been comercially developed for lane detection system of assistive funtion to drivers. There are so many driving systems that is capable of detecting lane for ideal environment like quite visible lane and sweep curve just like highway, but these kinds of system are hard to apply for self driving system because it is difficult to detect lane in dynamic environment, which have rapid curve or only one sided lane For this paper, we proposed intelligent driving system that is able to detect the lane in case of rapid curve by labeling, or one sided lane by lane prediction. based on experimental results, we prove our lane detection system is able to detect lane not only in ideal environment, but also environment which have rapid curve or one sided lane.