• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.4
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• pp.181-192
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• 2003

Increased vehicles on the restricted road, the conventional traffic light to losses the function of optimal cycle. The conventional traffic light dose not consider passenger car unit ,offset, and length of traffic intersection. As a result, 30~45% of conventional traffic cycle does not match the present traffic cycle. In this paper, we study the disard vantage of conventional traffic light and improve the vehicle average waiting time in the traffic intersection and vehicle average speed using fuzzy logic. Moreover, it will be able to forecast the optimal traffic information, road under construction and dangerous road using internet.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.85-94
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• 2016

Lane Designation is defined as reasonable road management to ensure the road safety and enhance road efficiency. While the lane designation system was abolished in 1999, it was redefined because of the increasing number of large vehicles in the passing lane, violent on driving and traffic accidents in 2000. The needs of improvement on operating the lane designation has been increasing more in recent due to the low ratio of compliance with the system and difficulties to keep the right lane due to need of turning and demand of widening of designates lane for two-wheeled vehicles and truck. In this study, we presented the improvement plan through the question survey, simulation analysis, safety evaluation. It found a problem that the low-speed vehicle is to use the upper level roadway, difficulties of supervision, the imbalance in the lane use, imbalance traffic and does not match the international standards. This study suggested five different alternatives through the survey. micro simulation has used in order to examine each alternative by management effectiveness and feasibility. It analyzed the traffic speed, efficiency, traffic balance of alternatives. Also, safety evaluation conducted in terms of the range of field-of-view to ensure the easiness of field of view by various configurational difference between the vehicles. By the analysis results of such indicators, This study presents proposals for improvement in operating designated lane that low-speed-big-sized vehicles keep to the right lane, and high-speed-small sized vehicles keep to the left lane.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.28-38
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• 2001

Traffic information can be broadly categorized into point information and spatial information. Point information can be obtained by chocking only the presence of vehicles at prespecified points(small area), whereas spatial information can be obtained by monitoring large area of traffic scene. To obtain spatial information by image processing, we need to track vehicles in the whole area of traffic scene. Image detector system based on global tracking consists of video input, vehicle detection, vehicle tracking, and traffic information measurement. For video input, conventional approaches used auto iris which is very poor in adaptation for sudden brightness change. Conventional methods for background generation do not yield good results in intersections with heave traffic and most of the early studies measure only point information. In this paper, we propose user-controlled iris method to remedy the deficiency of auto iris and design flame difference-based background generation method which performs far better in complicated intersections. We also propose measurement method for spatial traffic information such as interval volume/lime/velocity, queue length, and turning/forward traffic flow. We obtain measurement accuracy of 95%∼100% when applying above mentioned new methods.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.111-119
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• 2013

PURPOSES: Though the situation that the roundabouts are actively constructed, researches on the effect of the roundabouts focus mainly on the analysis of the expected effects of using only traffic simulation on the operation. Considering such problems, this study is conducted to analyze the effects of the various aspects based on field observation studies. METHODS: This study evaluated and analyzed the effects from the aspects of traffic operation, traffic safety, and traffic behavior by performing field observation studies with six roundabouts with/without signal controls on the pilot project areas for the roundabouts installed in 2010. RESULTS: Through the study results, it was found that the average travel time decreases by 14.7% and 2.4% on the signalized intersections and unsignalized intersections, respectively. The average travel speed increases by 9.7 and 5.8km/h on the roundabouts with/without signal lights. Regarding traffic safety, the speed deviation among individual vehicles decreases by approximately 18.4 to 32.7km/h, thus confirming the safety effects. As the decrease of the number of conflicts, it might be explained that car crashes and collision with pedestrians decreased by 62.2% and 66.7%. Also the result shows that the lowest point of speed in roundabouts appears near the yield line on the entry area on the roundabouts. When passing through the roundabouts, vehicles enter at a speed of 20-30km/h, which is the design speed of the circulatory lane and drive out the roundabout with a higher speed than the entry speed. CONCLUSIONS: When a roundabout is introduced at the intersections below certain traffic volume there are effects of traffic operation, traffic safety, and traffic behavior.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1492-1501
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• 2015

This paper analyzes the effect of voltage sag on distribution systems due to the connection of Electric Vehicles (EVs). In order to study the impact of the voltage sag on the power system, two scenarios have been selected in this paper. The distribution system and EVs are modeled using the Electro Magnetic Transients Program (EMTP). The numbers of EVs are predicted based on the number of vehicles in distribution system of Seoul. In addition, the number of EVs is set up using real-time traffic in Seoul to simulate Scenario I and II. The simulation results show that voltage sag can occur if the distribution system has more than 30% of the total number of vehicles.

• Computational Structural Engineering
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• v.10 no.4
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• pp.337-347
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• 1997

The dynamic responses of highway bridges are varying depending on the features of either traveling vehicles or bridges. In this study, the probabilistic characteristics of dynamic amplification factors of highway bridges due to traveling heavy vehicles have been examined through analytical simulation processes. The truck with tandem axle and tractor with semitrailer are selected as the representative heavy vehicles, which are modeled with three dimensional 7-DOF and 12-DOF models, respectively. The analytical results have been compared with the experimental results of dynamic loading tests and the validity of the analytical models has been examined. Parametric studies on the means and extreme values of amplification factors have been performed with various traffic conditions such as vehicle types, vehicle weights, surface profiles, number of loading vehicles, loading positions, etc.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.495-503
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• 2016

Regulation for the testing and operation of autonomous vehicles on public roadways has been recently developed all over the world. For example, the licensing standards and the evaluation technology for autonomous vehicles have been proposed in California, Nevada and EU. But specific safety evaluation scenarios for autonomous vehicles have not been proposed yet. This paper presents safety evaluation scenarios for extraordinary service permission of autonomous vehicles on highways. A total of five scenarios are selected in consideration of safety priority and real traffic situation. These scenarios are developed based on existing ADAS evaluation and simulation of autonomous vehicle algorithm. Also, Safety evaluation factors are developed based on ISO requirements, other papers and the current traffic regulations. These scenarios are investigated via computer simulation.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.139-146
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• 2021

Ahead of the commercialization of autonomous vehicles, it's application should be considered into the current transportation infrastructure. Under limited traffic circumstances, effective set of lane change rules alone could bring benefits to the autonomous driving system. In this study, a cooperative movement (local platooning) plan with limited vehicles associated as pocket driving, aiming at effective movement between vehicles in urban environment was proposed. Under congested roadway condition, the gaussian gap between vehicles was introduced to secure gap acceptance for safe lane change maneuver. Proposed lane change method showed 86.6% delay reduction along with traffic volume improvement. This result could be considered as a crucial factor in designing a next-generation roadway infrastructure with autonomous driving.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.75-96
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• 2016

This paper investigates the usefulness of drones in an urban delivery system. We define the vehicle and drone routing problem with time window (VDRPTW) and present a model that can describe a dual mode delivery system consisting of drones and vehicles in the metropolitan area. Drones are relatively free from traffic congestion but have limited flight range and capacity. Vehicles are not free from traffic congestion, and the complexity of urban road network reduces the efficiency of vehicles. Using drones and vehicles together can reduce inefficiency of the urban delivery system because of their complementary cooperation. In this paper, we assume that drones operate in a point-to-point manner between the depot and customers, and that customers in the need of fast delivery are willing to pay additional charges. For the experiment datasets, we use instances of Solomon (1987), which are well known in the Vehicle Routing Problem society. Moreover, to mirror the urban logistics demand trend, customers who want fast delivery are added to the Solomon's instances. We propose a hybrid evolutionary algorithm for solving VDRPTW. The experiment results provide different useful insights according to the geographical distributions of customers. In the instances where customers are randomly located and in instances where some customers are randomly located while others form some clusters, the dual mode delivery system displays lower total cost and higher customer satisfaction. In instances with clustered customers, the dual mode delivery system exhibits narrow competition for the total cost with the delivery system that uses only vehicles. In this case, using drones and vehicles together can reduce the level of dissatisfaction of customers who take their cargo over the time-window. From the view point of strategic flexibility, the dual mode delivery system appears to be more interesting. In meeting the objective of maximizing customer satisfaction, the use of drones and vehicles incurs less cost and requires fewer resources.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.167-175
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• 2013

PURPOSES : The objective of this study is to investigate the capability of the combined model of traffic simulation, emission and air dispersion models on the impact analysis of air quality of mobile sources such as vehicles. METHODS : The improvement of the quality of life brings about the increasing interest of the public environment. Many endeavors including the travel demand management, the application of the state-of-the-art ITS technologies, the promotion of eco-friendly vehicles have been tried in transportation area to reduce the modal emissions. Especially, it is expected that the increasing number of eco-friendly vehicles in the road network would be able to reduce the pipe-tail emissions tremendously. From this perspective, we have performed a study on the impact analysis of the popularization of the eco-friendly vehicle in the place of the fossil fuel energy powered vehicles on the surrounding air quality using the combined framework of microscopic traffic simulation, emission and air dispersion model. RESULTS : The combined model successfully captured the effect of moving to the eco-friendly vehicles on the air quality, and the results showed that the increasing usage of eco-friendly vehicles can improve the surrounding air quality tremendously and that the air dispersion model plays a crucial role in the investigation of the air quality change around the main corridor. CONCLUSIONS : This study demonstrated the capability of the combined model showing the spatio-tempral change of emission concentration.