• Journal of Korean Society of Transportation
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• v.32 no.4
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• pp.293-302
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• 2014

Recently, advanced sensors and communication technologies have been widely applied to advanced safety vehicles for reducing traffic accidents and injury severity. To apply the advanced safety vehicle technologies, it is important to quantify safety benefits, which is a fundamental for justifying application. This study proposed a methodology for quantifying the effectiveness of the Advanced Driver Assistant System (ADAS) with the Analytic Hierarchy Process (AHP). When the proposed methodology is applied to 2008-2010 Gyeonggi-province crash data, ADAS would reduce about 10.18% of crashes. In addition, Adaptive Cruise Control, Automatic Emergency Braking System, Lane Departure Warning System and Blind Spot Detection System are expected to reduce about 10.43%, 10.17%, 9.96%, and 10.18%, respectively. The outcomes of this study might support decision making for developing not only vehicular technologies but also relevant safety policies.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.38-50
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• 2018

Emerging automated driving environments will lead to a mixed traffic flow depending on the interaction between automated vehicles (AVs) and manually driven vehicles (MVs) because the market penetration rate (MPR) of AVs will gradually increase over time. Understanding the characteristics of mixed traffic conditions, and developing a method to control both AV and MV maneuverings smoothly is a backbone of the traffic management in the era of automated driving. To facilitate smooth vehicle interactions, the maneuvering of AVs should be properly determined by various traffic and road conditions, which motivates this study. This study investigated whether the aggressiveness of AV maneuvering, defined as automated driving aggressiveness (ADA), affect the performance of mixed traffic flow. VISSIM microscopic simulation experiments were conducted to derive proper ADAs for satisfying both the traffic safety and the operational efficiency. Traffic conflict rates and average travel speeds were used as indicators for the performance of safety and operations. While conducting simulations, level of service(LOS) and market penetration rate(MPR) of AVs were also taken into considerations. Results implies that an effective guideline to manage the ADA under various traffic and road conditions needs to be developed from the perspective of traffic operations to optimize traffic performances.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.488-496
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• 2015

The main reason to install pedestrian pushbuttons is improving traffic operations. The current guideline for the installation of signal systems with pedestrian pushbuttons is car-oriented. It is difficult to clearly understand the guideline because there isn't an in-depth study to compare the pros and cons of the pedestrian- and vehicle-oriented methods in terms of waiting time. Thus, this study aims to estimate the waiting times of pedestrians and vehicles. The two delay times are compared considering the hypothetical circumstances such as geometry, pedestrian crossing time, pedestrian/vehicle counts and arrival distribution. The results show that when the pedestrian traffic volume exceeds 97 ped/h in the case of a two-lane road (one lane in each direction) the pushbutton system is effective and beneficial to pedestrians. It means that the total waiting time of pedestrians is less than the one of vehicles. Additional four scenarios are designed and tested by varying the number of lanes and design speeds. In conclusion, the pushbutton signal is more beneficial for pedestrians when the number of pedestrians is less than or equal to 85, 70, and 70 ped/h for the three-lane scenario, the four-lane with the design speed of 80km/h scenario, and the four-lane with the design speed of 100km/h, respectively.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.98-111
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• 2018

Truck platooning, which is a cluster of trucks in support of vehicle-to-vehicle communication and automated longitudinal vehicle control, is a promising method to both operational efficiency and prevent traffic crashes. Although a variety of studies have been conducted to identify the effects of vehicle platooning on traffic stream, we are not aware of any study attempting to identify promising road segments for vehicle platooning. This study aims to develop a methodology for determining the priority of freeway segments that would potentially lead to maximize the effectiveness of truck platooning. Evaluation measures derived in this study includes truck crash rates, the percentage of truck traffic, segment length, and the number of entry and exit points. Weighting values obtained from an analytical hierarchical process (AHP) method were applied to compute the proposed priority score to determine better freeway segment for truck platooning. Results suggested that a 46.9km freeway segment, from Sacheon IC to Sanin JC, was the most promising segment for maximizing the effectiveness of truck platooning. It is expected that the outcome of this study would be effectively used as a fundamental to establish operational strategies for truck platooning.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2006.05a
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• pp.95-108
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• 2006

Because of rapid expansion of third party logistics, fierce competition in the transportation industry, and the diversification and globalization of transportation channels, an effective transportation planning by means of multimodal transport is badly needed. Accordingly, this study aims to suggest an optimal transport algorithm for the multimodal transport in the international logistics. Cargoes and stopovers can be changed numerously according to the change of transportation modes, thus being a NP-hard problem. As a solution for this problem, first of all, we have applied a pruning algorithm to simplify it, suggesting a heuristic algorithm for constrained shortest path problem to find out a feasible area with an effective time range and effective cost range, which has been applied to the Label Setting Algorithm, consequently leading to multiple Pareto optimal solutions. Also, in order to test the efficiency of the algorithm for constrained shortest path problem, this paper has applied it to the actual transportation path from Busan port of Korea to Rotterdam port of Netherlands.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.1
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• pp.95-95
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• 1987

The purpose of this research is to suggest a desirable framework to promote EDI system in the Korean trade and transportation industries. First, this thesis reviews the trend of introduction of EDI systems in foreign countries and investigates their characteristics by examining some cases. Then the problems, which the Korean industries would be confronted with during the course of introduction of EDI system, are identified and discussed. Finally, this thesis suggests that the logistics network should be developed as a main system of EDI to which sub-networks of trade and custom service are linked. This leading role of logistics metwork is necessary to the EDI system because logistics tasks for international movement of goods are expected to increase while tasks related to trade and custom services will decrease in view of recent changes in the world trade environments warning the unbounded competition in the global marketplace without border.

• Korean Management Science Review
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• v.12 no.1
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• pp.95-109
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• 1995

The purpose of this research is to suggest a desirable framework to promote EDI system in the Korean trade and transportation industries. First, this thesis reviews the trend of introduction of EDI systems in foreign countries and investigates their characteristics by examining some cases. Then the problems, which the Korean industries would be confronted with during the course of introduction of EDI system, are identified and discussed. Finally, this thesis suggests that the logistics network should be developed as a main system of EDI to which sub-networks of trade and custom service are linked. This leading role of logistics metwork is necessary to the EDI system because logistics tasks for international movement of goods are expected to increase while tasks related to trade and custom services will decrease in view of recent changes in the world trade environments warning the unbounded competition in the global marketplace without border.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.97-104
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• 2010

Expanded muti-source Weber problem (EWP), which introduced in this paper, is a reverse logistics network design problem to minimize the total transportation cost from customers thorough regional center to central center. Decision factor of EWP are the locations of regional centers and a central center. We introduce a GRASP heuristics for the EWP. In the suggested GRASP, an expanded iterative location allocation method (EILA) is introduced based on the Cooper's iterative location allocation method[3]. For the initial solution of GRASP, allocation first seed (AFSeed) and location first seed (LFSeed) are developed. The computational experiment for the objective value shows that the LFSeed is better than the AFSeed. Also the calculating time of the LFSeed is better than that of the AFSeed.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.369-376
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• 2014

The national Logistics Information system has been rapidly developed on account of the dramatic improvements in the military's logistics support system and supply support system, making a transition from manual work system to computerized work system. Supply level, however, does not reflect these changes in the overall logistics environment and still retains the state it was in the 1970s. This research uses the accumulated data from the equipment maintenance information system developed in the year 2009 to analyze RWT(Requisition Wait Time) and CWT (Customer Wait Time). The analysis estimated the realistic transportation and ordering time and led to the conclusion that the differentiated ASL operation system that considers demand level should be adopted instead of the uniform ASL employment system.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.985-990
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• 2005

The success of road transportation, in dominating the surface movement of freight, is now threatened by increased traffic congestion, falling average motorway speed and rising in logistics costs, oil price. Due to the necessity for an effective transport system, we need to improve domestic transport infrastructure to reduce logistics cost by shifting to rail system. To analysis the demand characteristics in advance against these hypothetical circumstances, Stated Preference, which is called SP, approaches have been adopted to analysis the shipper's mode choice behaviors as RP(Revealed Preference) approaches are not appropriate. The results also indicate that the most effective policy to divert the freight volume from road to railway is to reduce freight rates for the railway with improved reliability.