• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.305-316
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• 2013

To find out if modern roundabout is still effective under drivers behavior and driving conditions in Busan Metropolitan City, the effects before and after introduction of roundabout were analyzed. According to analysis on velocity profile at roundabout, velocity deviation decreased, and average vehicle speed was close to design speed. As a result, it has been confirmed that most roundabouts were properly built. In terms of traffic operation, average vehicle speed improved by 87.2% when a traffic intersection was replaced by a roundabout. therefore, it has been found out that the introduction of roundabout has a positive effect on increasing vehicle speed by reducing traffic congestion. In addition, annual benefits expected from the replacement from a traffic intersection to a roundabout were KRW 872 million as follows; KRW 410 million in traffic communication, KRW 39 million in transportation safety, KRW 255 million in energy saving, KRW 95 million in reduction of air pollution and KRW 73 million in reduction of traffic signal installation cost. In other words, if 10% (193 spots) of all traffic intersections (1,926 spots in total) in Busan City are replaced by roundabouts, the municipal authority would be able to save about KRW 168.3 billion. According to analysis on the benefits expected from the installation of roundabouts compared to the investment cost for traffic intersections, about KRW 679 million could be saved per roundabout. Considering 10% of all traffic intersections in the City of Busan, about KRW 131 billion could be saved annually. The traffic accidents in roundabout usually occur because drivers aren't aware of right-of-way rules. Once the right-of-way rules settle, the number of traffic accidents would significantly decrease. In addition, it is urgent to promote education and campaign for drivers, pedestrians and bikers on the roundabout.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.10
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• pp.948-956
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• 2014

Today, Intelligent Vehicle Detection System seeks to reduce the negative factors, such as accidents over to get the traffic information of existing system. This paper proposes detection algorithm for the illegal U-turn vehicles which can cause critical accident among violations of road traffic laws. We predicted that if calculated optical flow vectors were shown on the illegal U-turn path, they would be cause of the illegal U-turn vehicles. To reduce the high computational complexity, we use the algorithm of pyramid Lucas-Kanade. This algorithm only track the key-points likely corners. Because of the high computational complexity, we detect center lane first through the color information and progressive probabilistic hough transform and apply to the around of center lane. And then we select vectors on illegal U-turn path and calculate reliability to check whether vectors is cause of the illegal U-turn vehicles or not. Finally, In order to evaluate the algorithm, we calculate process time of the type of algorithm and prove that proposed algorithm is efficiently.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.585-590
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• 2017

In this paper, a low power of safety oriented sidewalk block was implemented using dimming technology using LED and illuminance sensor to prevent glare by high - intensity light source and prevent night traffic accident. The dimming system of this paper used a light bulb color with less fatigue to prevent glare and consumed 6.10Wh power. Also, it is confirmed that the power saving is about 56.9% when compared with the existing system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.719-726
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• 2006

The use of CWR track not only reduces the track maintenance cost, but increase the life cycle of track components. Therefore, the use of the CWR track has increased consistently in the worldwide. As the use of CWR increases in track structures, derailing disasters associating with track buckling also increase in great numbers due to high compressive thermal stress in the summer. Among many CWR parameters, the influence of the sectional properties of the rail was investigated on the stability of CWR track in this study. Also, the sensitivity of the broken fastener and the stiffness of the fastener system such as the translational and rotational stiffness was investigated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.513-522
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• 2010

Underground construction for traffic networks, complexes, and storage facilities has risen as an effective land use plan for dealing with emerging problems such as overcrowded urban cities and traffic jams. This paper performed an economic feasibility analysis of the development of the integrated field management system which provides field workers and managers with 3D-based location tracking and clear communication during underground construction works. To conduct the analysis, processes and problems of field management for underground construction were analyzed and deduction in accidents and field management costs and productivity improvement were estimated as expected benefits. Based on computed benefits and costs, an economic analysis was conducted using Benefit/Cost ratio(B/C), Net Present Value(NPV), and Internal Rate of Return(IRR) and then sensitivity analysis was performed to cope with the uncertainty of assumed variables.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.36-49
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• 2016

A subway system is one of the major transportation modes at a metropolitan area. When it meets the other lines, the metro station, so-called transferring station, is usually threatened by severe pedestrian congestion and safety issue of transit users including the transportation vulnerable. Although transportation planners forecast travel demand at the beginning, it is not easy to predict pedestrian flows precisely for a long term if land use plans have dramatically changed. Due to expensive costs, structural extension of metro stations is limited. Therefore, it requires efficient and technical improvements as meeting the demand of pedestrian and physical characteristics. In this study, the core mechanism of pedestrian movement-based simulation model was introduced and evacuation scenarios were analyzed with the developed model. As a result, the multiple optimal routes for unexpected events at the solid space of the multiple stories are easily searched through the simulator and in the case of Sadang Station, travel time can be reduced by 60% when the evacuation information and intuitive design are provided.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.243-248
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• 2015

Domestic road and railroad construction have been increasingly growing and for reasons of mitigating traffic congestion, urban plan and refurbishment project, deeper and longer tunnels have been built. The event of fire is the most fatal accident in a tunnel, and it can be very disastrous with a high possibility. In this study, QRA (Quantitative Risk Analysis) which is one of quantitative risk analysis approaches was applied to tunnel fire safety design and the evaluation of QRA cases and the cost comparison of QRA methods were carried out. In addition analysis of risk reduction effect of tunnel fire safety system was conducted using AHP (Analytic Hierarchy Process) and the priority of major factors that could mitigate the risk in tunnel fire was presented. As a result, significant cost reduction effect could be obtained by incorporating QRA and it is expected to design fire safety system rationally. The priority of fire safety system based on risk mitigation effect by fire safety system considering the cost is in order of water pipe, emergency lighting, evacuation passage and smoke control system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.632-637
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• 2016

A streetlight control system was developed using information technology and LED lights for efficient management and energy savings. The proposed system can control the power usage of an LED streetlight luminaire using GPS satellite communication and an Arduino with a built-in microprocessor. A control circuit was designed to control the current using GPS, a control unit, transistor, resistor, and constant-current supply circuit. The circuit was validated through experiments with normal operation. Using GPS, the control system extracts accurate time and location information according to the season, and it controls the current supplied to the LED streetlight according to the extracted time. Power consumption was reduced by more than 11%. The control system could reduce accidents caused by conventional lighting systems used to save energy, and it could improve the inefficient management of energy by preserving constant brightness of a streetlight at times and in areas that have less traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.131-136
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• 2015

The feasibility study is an evaluation and analysis of the potential of a proposed project. It is based on extensive investigation and research to support the process of decision making. A systematic approach to determining the optimum use of scarce resources, involving comparison of two or more alternatives in achieving a specific objective under the given assumptions and constraints. Economic analysis takes into account the opportunity costs of resources employed and attempts to measure in monetary terms the private and social costs and benefits of a project to the community or economy. Cost-benefit analysis (CBA), sometimes called benefit-cost analysis (BCA), is a systematic approach to estimating the strengths and weaknesses of alternatives that satisfy transactions, activities or functional requirements for a business. It is a technique that is used to determine options that provide the best approach for the adoption and practice in terms of benefits in labor, time and cost savings etc. The CBA is also defined as a systematic process for calculating and comparing benefits and costs of a project, decision or government policy and projects.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.67-76
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• 2012

In this study, we established objective appraisal standard by applying newly made appraisal standard to those areas equipped with the protection system targeted to the Mobility handicapped announced in this edition (issue 5, volume 9(Oct., 2010)) beyond simple evaluation related to protector satisfaction. Additionally, we achieved efficient budget execution by conducting the preliminary estimation assessment regarding those areas on which recognition devices should be newly deployed. Through the assessment of the system coordination, the maximum safety distance is proved to be 72.2m. On the basis of this result, we applied dangerous grade to the deployment of recognition devices considering both psychological and accidental risk. With this, we proposed valuation basis to enable us to do future business. Based on this assessment standard, the degree of risk is proved to decrease by 35.2% compared to before conducting the demonstration project in terms of evaluation of comprehensive risk regarding intended areas. Additionally, we confirmed the fact that the degree of risk can decrease by 33.1% totally after having recognition devices built according to the deployment standard within budget. Furthermore, comprehensive risk can decrease up to 94% compared to the level of the demonstration project even though we spend 21.9% less of the existing budget. Hence, we can say that the deployment method of recognition devices related to the degree of risk is applied efficiently in the near future in terms of controlling comprehensive risk and cutting down budget through this study.