• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.612-618
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• 2020

In recent years, the demand for external window cleaning has increased, but the process is a very dangerous manpower-dependent operation. In addition, it is difficult to clean at the desired frequency in a business that values cleanliness. Therefore, there is a need to automate this work. This paper presents the concept of a device that can be attached to a specific window and clean the window continuously. The economic feasibility of this device was analyzed. The estimated manufacturing cost of the equipment was approximately 10 million won, but the possible investment cost was at least 9.8 million won for five years of endurance and 103 million won for 10 years of endurance. Therefore, the expected savings well exceed the equipment cost, and it was evaluated as having economic feasibility. Since this study analyzed only quantitative indicators, the expected cost reduction due to a reduction in safety accidents, productivity improvement, construction time reduction, and quality improvement was not considered. Therefore, it is expected that the calculated economic feasibility will be more accurate if the cost reduction effect by the automation equipment is calculated by adding the expected values not considered in this study.

• 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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.2 s.10
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• pp.61-71
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• 2006

The main purpose of this study is to search a method for reducing traffic accident at signalized intersections. One of the important factors for this is the Left-turn phase sequence. In 1985, the operational principle of Left-turn phase Sequence was changed from Lagging left-turn to Leading left-turn in Korea. Then there was a resonable motive-no exclusive left turn-lane and narrow intersection. So, it is necessary to evaluate the performance difference between Leading and Lagging left -turn phase Sequence. The process of this study is as follows: $\cdot$ First, all the intersection was divided three parts for analysis the traffic safety: Inside part of an Intersection, Crosswalk, Intersection approach and exit. $\cdot$ Second, a safety analysis was performed by using the concepts of 'Effective interphase Period(EIP)' and 'Conflict method' The Study result is that the benefit of of phase Sequence changes from Leading to Lagging phase were significant. For an example the Accident cost will reduced about 41.8 billion won per year in korea.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.110-117
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• 2008

The risks of the chemical facilities were estimated by the KS-RBI(Ver. 3.0) program supporting the quantitative cause analysis, and reduction method for the risks of the facilities was investigated. As a result, we could find that the risks of the facilities decrease with reducing the likelihood of failure (LOF) affected by demage mechanism, inspection number and effectiveness of inspection, and with reducing the consequence of failure (COF) affected by the ratings of the detection, isolation, and mitigation systems. Furthermore, high risks of the facilities would be decreased by reduction of the LOF and the COF simultaneously. Accordingly, the applied plant would be able to achieve the decrease of inspection and labor costs because of the decrease of consequences and inspection intervals through the reduction of risks.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.51-57
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• 2019

A plant layout problem has a large impact on the overall construction cost of a plant. When determining a plant layout, various constraints associating with safety, environment, sufficient maintenance area, passages for workers, etc have to be considered together. In general plant layout problems, the main goal is to minimize the length of piping connecting equipments as satisfying various constraints. Since the process may suffer from the heat and friction loss, the piping length between equipments should be shorter. This problem can be represented by the mathematical formulation and the optimal solutions can be investigated by an optimization solver. General researches have overlooked many constraints such as maintenance spaces and safety distances between equipments. And, previous researches have tested benchmark processes. What the lack of general researches is that there is no realistic comparison. In this study, the plant layout of a real industrial C3MR (Propane precooling Mixed Refrigerant) process is studied. A MILP (Mixed Integer Linear Programming) including various constraints is developed. To avoid the violation of constraints, penalty functions are introduced. However, conventional optimization solvers handling the derivatives of an objective functions can not solve this problem due to the complexities of equations. Therefore, the PSO (Particle Swarm Optimization), which investigate an optimal solutions without differential equations, is selected to solve this problem. The results show that a proposed method contributes to saving the capital expenditures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.93-99
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• 2017

The rate of traffic accidents that occurred in Korea last year is 10 out of every 100,000 people, ranking it 6th among the 35 OECD member countries. The accident rate of children with disabilities and elderly people is also high. The purpose of this study is to introduce traffic safety facilities which have been developed for the reduction of traffic accidents in non-urban areas in Korea through an analysis of the related literature, the accident factors using traffic accident analysis system data and traffic accident characteristics. Traffic safety integrated facilities for ICT-based pedestrian crossings are subject to cross-sectional coverage of child protection zones. The smart safety fence prevents vehicles from parking illegally and informs pedestrians that there is an access vehicle on the pedestrian crossing. The smart bump is designed to warn drivers who are not aware of the pedestrians. In order to standardize the appropriate form and size of the traffic safety facilities for pedestrian crossings, we constructed a standard model for each type, considering the road function, press classification, power, lane number, geometric form, etc. As a result, the rate of traffic accidents involving vulnerable people was reduced. In addition, it is anticipated that the maintenance costs will be reduced by the use of a solar power supply and their compatibility with the existing installed safety fences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.577-586
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• 2018

In this study, traffic safety technology was developed for rural areas by reviewingthe relevant literature and data from the Traffic Accident Analysis System for the Chungcheong region.The goal is to reduce traffic accidents in small regional cities and rural areas in Korea. A road shoulder recognition light was developed to fit the pedestrian characteristics of the people using transportation in rural areas. It also minimizes damage to crops due to light pollution from traffic lights and street lights, and it supplements problems of damage from collision with vehicles and agricultural machines. The efficiency of the technology developed in this study was verified by comparing and analyzing the number of traffic accidents and the saved cost before and after its installation. A test bedwas established based on rural areas and is being evaluated for its applicability and effectiveness. It is expected that the reliability of such facilities could be improved through continuous studies, data collection, and analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.502-508
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• 2007

This paper proposes a method to shut out all of the not certified network access packet by embodying the two-factor(MAC ADDRESS, ID/PASSWORD) authentication system. The Authenticating Gateway System takes over central server's policy and permit or hold up the packet by inherited policy. And checks the whether or not patched the OS version and getting influenced from computer virus. And takes the information about client's resources(H/W, S/W) without Agent in the client. That makes more stability of network operating circumstance and fast facing the attack from hackers. In the fixed mobile network circumstance, This method provides more simplicity and less expenses than IEEE802.1x authentication system(cisco nac).

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.218.1-218.1
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• 2010

천연가스를 대체하며 21세기 신 에너지원으로 기대되고 있는 메탄 하이드레이트가 주목을 받게된 것은 1930년대 시베리아의 화학 플랜트에서 고압의 천연가스 수송용 파이프라인이 막히는 사고가 빈번하게 발생하여 그 원인을 조사한 결과, 파이프 내에서 가스와 물이 결합하여 하이드레이트를 형성하고, 그것이 파이프의 내벽에 부착되어 파이프를 막고 있다는 것으로 밝혀지면서 천연가스 하이드레이트가 주목을 받게 되었다. 또한 메탄 하이드레이트의 경우 46개의 물분자에 8개의 메탄가스 분자가 포획된 구조로, 그 분자식은 $CH_4{\cdot}5.75H_2O$이다. 따라서 메탄가스와 물의 이론적 용량비가 216:1로써, 표준상태에서 $1m^3$의 메탄 하이드레이트는 $172m^3$의 메탄가스와 $0.8m^3$의 물로 분해된다. 만약 이와 같은 특징을 역으로 이용할 경우 메탄을 주성분으로 하는 천연가스를 물에 포집시켜 인공적으로 하이드레이트를 제조할 수 있기 때문에 천연가스 수송 및 저장의 수단으로써 그 중요성이 커지고 있으며, 액화수송보다 18-24%의 비용절감이 이루어진다고 보고하였다. 그러나 인공적으로 메탄 하이드레이트를 제조할 경우 가스 포집율의 예측이 매우 어려운 것으로 알려져 있다. 따라서 본 연구에서는 동일한 조건에서 메탄 하이드레이트 형성의 반복성 실험을 10회 수행한 결과 과냉도가 클수록 최대최소차이가 줄었고 또한 교반을 시킬 경우도 최대최소차이가 줄어 들었다.

• Culinary science and hospitality research
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• v.13 no.3
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• pp.317-327
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• 2007

The purpose of this study was to explore the relationship between the food safety-oriented policy and the survey on its effect in foodservice industry. The current thesis was based on the questionnaire survey conducted between January and March 2006 for seven food service companies. 240 questionnaires were distributed to each of the selected restaurants, from which a total of 200 questionnaires were collected. The results of this study were analyzed with the frequency analysis, correlative analysis and regression analysis using the SPSS 12.0 package program. The results of the test of hypotheses can be summarized as follows. We find that, as for food safety-oriented policy factors, there is a significant relationship among the survey factors including customer satisfaction, cost reduction, customer prior occupation, accident prevention and suitable relation. The current analysis exhibits favorable results in the food safety-oriented policy and the survey factors. Thus, foodservice management needs to employ food safety-oriented policy aggressively.