• Journal of IKEEE
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• v.21 no.2
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• pp.115-122
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• 2017

In vehicular safety service, every vehicle broadcasts Basic Safety Message (BSM) periodically to inform neighbor vehicles of host vehicle information. However, this can cause network congestion in a region that is crowded with vehicles resulting in a reduction in the message delivery ratio and an increase in the end-to-end delay. Therefore, it could destabilize the vehicular safety service system. In this paper, in order to improve the congestion control and to consider the hidden node problem, we propose a congestion control scheme using entire network congestion level estimation combined with transmission power control, data rate control and time slot based transmission control algorithm. The performance of this scheme is evaluated using a Qualnet network simulator. The simulation result shows that our scheme mitigates network congestion in heavy traffic cases and enhances network capacity in light traffic cases, so that packet error rate is perfectly within 10% and entire network load level is maintained within 60~70%. Thus, it can be concluded that the proposed congestion control scheme has quite good performance.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.54-59
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• 2018

While the advanced trffic environment systems are developed recently, the traffic systems for transportation vulnerable are still under development and their social life are limited as well. In order to the secure their mobility rights, it had been required to set up the particular system for the traffic welfare. One of the significant items is the express bus operation for wheelchair users. Thus, the research of development and operation for express buses with wheelchair users was funded by the Korean government. Before the express bus development for wheelchair users based on the current bus model, this study set up the evaluation method for the bus rollover characteristics to ensure occupant safety using the finite element method. The partial bus model was developed corresponding to the full bus model response under rollover event and the evaluation method based on two model (full bus model and partial bus model) responses is planned to apply the model development of express bus modification for wheelchair users.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.1-7
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• 2005

In order to secure the traffic safety especially in the entrance waterway of harbour, it is important that the breakwater and the port facilities should be designed properly considering ship-handling difficulty and traffic flow. In this study, the lateral force acting on ship hull under the external force(wind, current, wave) is investigated quantitatively for the container ship approaching to the Busan and Gamcheon breakwater. The relation of ship-handling difficulty to the breakwater and the arrangement of ship's routine are examined based on the lateral force under the external force. Some of reviews to secure traffic safety on the design of breakwater are discussed.

• Journal of the Korean Institute of Navigation
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• v.10 no.2
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• pp.31-55
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• 1986

Generally, the development of shipping is characterized by the amount of traffic flow (traffic volume) and seaborne cargo in the sea. Movement of ships is an essential element of constructing the traffic flow which is represented the dynamic movement of ships in the sea, but on the other band the numbers of arriving and departing the port is the basic factor consisting of the static movement of ships. The amount of cargoes by coastal vessels and ocean trade vessels have increased tremendously with the great growth of the Korean economy these days. This increase of the seaborne cargoes has made the Korean coastal traffic flow so congested that this can be a cause of large pollution as well as great marine casualities such as a loss of human lives and properties . And also the future coastal traffic is expected to increase considerably according to our economic development and high dependence upon foreign trade. Under the circumstance, to devise the safety of coastal traffic flow and to take a proper step of a efficient navigation, there is a necessity for analyzing and surveying the coastal traffic trend and the characteristics of cargo movement. In order to grasp the dynamic movement of ships in the Korean coast, O/D analysis is executed. This paper aims to secure the basic data necessary for a comprehensive plan and estimation of vessel traffic management system for the enhancement of safety, order and efficiency of vessel traffic in the Korean coast. The analyzed results of the traffic flow and seaborne cargoes of the Korean coast are summarized as follows : 1) The congestion by the vessels occurred around the ports such as-in proportion of ship's number (proportion of tonnage) -Incheon 18.5%(14.8%), Pohang 5.9% (9.9%), Samil 5.2%(8.3%), Mokpo 8.6%(0.8%), Pusan 13.5%(36.4%), Ulsan 9.1%(16.2%). 2) It is found that the area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed thatthe area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed that the coastal vessels are main elements constituting the coastal traffic and that there are much traffic flow among five ports as following through the precise O/D analysis of ship's coastal movement. Incheon-Samil, Ulsan, Pusan, Jeju Pusan -Samil, Ulsan, Incheon, Jeju Pohang -Samil, Inchoen, Jeju Pohang -Samil, Incheon, Jeju Ulsan -Samil, Incheon, Jeju Samil -Ulsan, Pusan, Incheon 4) The amount of cargoes to abroad are in proportion about 81% of total and the amount of coastal cargoes are about 19%. Of those, cargoes in and out to Japan are about 26% and to South-east Asia are about 27%. 5) The chief items of foreign cargoes are oil(38.33%), iron ore(13.98%), bituminoous coal(12.74%), grain(8.02%), lumber(6.45%) in the import cargoes and steel material(21.96%), cement(17.16%), oil(6.81%), fertilizer(3.80%) in the export cargoes. 6) The 80.5% of total export cargoes and 92.4% of total import cargoes are flowed in five main ports. 7) The chief items of coastal cargoes are oil (42.45%), cement(16.86%), steel material (6.49%), anthracite(6.31%), mineral product(4.3%), grain, and fertilizer. Almost 92.24% of total import and export oil cargoes in Korea is loaded and unloaded at the port of Samil & Ulsan.

• Wind and Structures
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• v.38 no.6
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• pp.411-425
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• 2024

To investigate the optimal aerodynamic parameters of wind barriers for the T-beam of high-speed railway (HSR) bridge and the wind field of the wind barrier-train-bridge system, the three-component forces of the system and the wind pressure on the vehicle surface were tested and analyzed through the sectional model wind test. The effects of wind velocity, with/without wind barrier, the height of wind barrier, and the air permeability of the wind barrier on the aerodynamic characteristics of the train-bridge system are discussed. Additionally, a CFD numerical model is constructed to evaluate the wind environment of the bridge surface with/without the wind barrier, and the impact of wind barrier on the running safety of vehicles are analyzed. Comprehensively considering the running safety of the train and the wind-resistant stability of the bridge, it is more appropriate to set the wind barrier height H as 3.5 m and the porosity 𝛽 as 30% respectively.

• Tunnel and Underground Space
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• v.23 no.6
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• pp.572-580
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• 2013

In this case study, I examined the microseismic safety management system of Deep Heat Mining Basel (DHMB) as EGS Geothermal Project which was conducted in Basel, Switzerland. EGS Geothermal Power projects which require induced seismic event by stimulation for creation of EGS geothermal reservoir have to be controlled pressure and flow rate of stimulation by establishment of microseismic safety management system. Traffic light system and Communication response procedure of DHMB project to respond step by step corresponding microseismic event intensity through continuous monitoring during stimulation period have been managed and established in advance of stimulation. However, the project was discontinued because of an earthquake to occur larger than expected one due to post-injection seismicity occurring in the geothermal reservoir after completion of injection for stimulation. The result of post analysis, Real-time traffic light system was verified to need a establishment of new microseismic safe management system to be considered post-injection seismicity phenomenon.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.321-324
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• 2001

The accidents in a railway level crossing where passengers or vehicles pass on the track went through by the train with a inherent high rate on incidents lead to a vast economic damage on people and material resources. So, many protection equipments are placed on the railway crossing to prevent those kind of accidents. But there is a limit to control driver's rough activity, passenger's careless or an intentional accident. This study is trying to ensure the safety in railway crossing by providing the information on train's speed and expected passing time on the railroad to a road traffic control system or car driver. Additionally, this system has been studying the railway level crossing system concerning ITS to support harmonious traffic flow.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.8
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• pp.101-109
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• 2019

Korea's transportation paradigm is shifting from a vehicle-oriented transportation plan to a pedestrian-friendly environment that emphasizes walking safety. However, the level of pedestrian traffic accidents in Korea is still high and serious. The purpose of this study is to investigate factors affecting the severity of pedestrians traffic accidents using the multilevel logistic regression model based on 2015-2017 pedestrian accidents data provided by the Traffic Accident Analysis System(TAAS). The main results of the multilevel logistic regression model showed that 89% of pedestrian traffic accidents in Seoul were explained by individual characteristics such as drivers and pedestrians, and 11% were explained by neighborhood environmental characteristics. The results are as follows : In the individual characteristics such as pedestrians and drivers, the older the pedestrians and the drivers, the higher the traffic accident severity. The severity of traffic accidents was high when the pedestrians were female and the drivers were male. In the case of accident types, traffic accidents were more serious in the cases of heavy vehicles, inclement weather, and occurring at intersections and crosswalks. The results of the neighborhood environmental characteristics are as follows. The intersection density and the crosswalk density tended to reduce the severity of traffic accidents. On the other hand, the traffic light density and the school zones were founded to related to the higher level of traffic accident severity. This study suggests that both individual and neighborhood environmental characteristics should be considered together to prevent and reduce the severity of pedestrian traffic accidents.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.29-32
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• 2007

본 논문에서는 게임에 사용되는 원리를 역으로 적용하여 교통안전 표지판을 인식하는 시스템을 구현하였다. 본 시스템에 사용된 게임은 제작자가 (x, y)좌표에 제공하는 수치를 보고 메쉬에 표시하면 제작자가 의도한 임의의 물체의 모형이 표현되는 게임이다. 입력된 영상으로부터 교통안전 표지판 영상을 분리한 후, 표지판을 구성하는 색상과 형태에 상기의 퍼즐게임을 이용하여 교통안전 표지판으로 인식되면 해당 표지판과 내용을 문자로 출력하는 시스템을 구현하였으며 흑백 영상 처리 및 세선화과정 없는 인식으로 처리 속도가 빠르며, 기존 시스템 보다 좋은 인식률을 얻을 수 있었다.

• Structural Monitoring and Maintenance
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• v.1 no.2
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• pp.173-182
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• 2014

We describe the application of a distributed optical fiber sensor based on stimulated Brillouin scattering, as an integrated system for safety monitoring of railway infrastructures. The strain distribution was measured statically and dynamically along 60 meters of rail track, as well as along a 3-m stone arch bridge. We show that, gluing an optical fiber along the rail track, traffic monitoring can be performed in order to identify the train passage over the instrumented sector and determine its running conditions. Furthermore, dynamic and static strain measurements on a rail bridge are reported, aimed to detect potential structural defects. The results indicate that distributed sensing technology represents a valuable tool in railway traffic and safety monitoring.