• Tunnel and Underground Space
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• v.15 no.6 s.59
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• pp.452-461
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• 2005

In a bidirectional tunnel, the accident rate is 1.5 times as high as that of one directional tunnel , the risk of a fire is increased. On fire, there is a problem that the jet fan should not be operated until completion of refuge. To be special, as the great damages occur owing to the expansion of smoke in long tunnels, there is a need to minimize fatality by constructing cross passage and smoke removal system. This study aims at verifying the efficiency of smoke exhaust system through fire propagation simulation as well as scale model test. The results show that completion of escape through emergency exit requires 335 seconds, while addition of smoke exhaust system reduce the escape time to 185 seconds. Also, near the fire source temperature decreased by about $60^{\circ}C$. Without the exhaust system, fire propagation speed was in the range of 0.36 and 0.82 m/s, and it dropped to $0.27\~0.58\;m/s$ with the exhaust system on. Taking into account the escape speed of tunnel users, usually $0.7\~1.0\;m/s$, the emergency exit built every 150m is sufficient for the safe egress. The ultimate goal of this study is to provide fundamental information for the smoke exhaust system in bidirectional tunnels.

• Journal of the Korea Safety Management & Science
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• v.22 no.3
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• pp.23-29
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• 2020

As the duty to report and investigate major elevator failures has expanded due to the total amendment of the Elevator Safety Management Act in 2018, more important information on major elevator failures that have been partially identified has been collected. As of 2019, the number of elevators in Korea exceeded 700,000, making it the eighth-class elevator powerhouse in the world, but there is a trend of increasing casualties due to accidents and breakdowns. An Seung-gang-gi is a term that encompasses an elevator that moves vertically and an escalator that moves horizontally. It is an important means of transportation for most citizens that are encountered almost every day in daily life, and it is also necessary as a means of transportation that enables the construction of skyscrapers. And it seems that its importance will never diminish in the future. Major elevator failures are the main cause of dispatch when accumulating the number of 119 dispatches, and the frequency of occurrence is high. It's a shame. According to Heinrich's Law, 300 minor signs and danger phenomena precede, 29 minor accidents and 1 major accident. Accidents caused by elevators are increasing every year due to the increase in the number of installations, and the damage is threatening the valuable lives and property of users and workers in related fields due to fatal risks such as death and serious injury. Elevator safety management can achieve its purpose only when it is managed with the usual interests, awareness of safety, and full efforts of the users, workers, and the government concerned. This study was analyzed based on 2019 data notified to the Korea Elevator Safety Agency on major breakdowns improved after the revision of the Elevator Safety Management Act in 2018, and a total of 8,256 data were analyzed using the SPSS 21 version, a statistical analysis tool, to analyze the correlation with technical statistics. Proceeded. Through the analysis, it was possible to obtain preventive safety management data to prevent serious elevator safety accidents from occurring, and to derive meaningful implications that related safety management and maintenance can be effectively operated to prevent serious failures. In addition, through this analysis, we expect the development of related industries and legal and institutional improvement.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.112-128
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• 2018

We are implementing pedestrian priority zone policy to certain districts to reduce greenhouse gas and to develop eco-friendly city which has more focus on pedestrians' walking environment. This policy has contributed to citizens' satisfaction level with improved public transportation service as well as more spacious streets for walk. Despite highly positive influence of pedestrian priority zone policy to the walking environment, we need to anticipate the impact of this to traffic environment as it may have bad effect to the overall traffic flow around the zone where the policy is implemented. This research has analyzed the change of characteristics of traffic accidents around the eco-traffic area of Hang-Gung dong, Suwon city, to understand impact of the pedestrian priority zone policy to the traffic surroundings, with pre-post analysis methodology. As a result, number of accidents related to pedestrians showed decrease as pedestrian priority zone is designed operated with focus to pedestrians. But accidents related illegal U-turn and violation of the traffic signal showed (significant) increase as there was a restriction of turns and decrease of overall traffic speed. To prevent the accidents above, we need to notice drivers to pay special attention before the pedestrian priority zone event, and information from this research should be given to the drivers through safety signs and mobile application at the place near to the event.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.133-138
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• 2003

The data on outbreaks of puffer fish poisoning during 1991 to 2002 in Korea were gathered from press reports, and characterized information collected. During the period, a total of 32 outbreaks of puffer fish poisoning was reported. These outbreaks caused 111 persons to become poisoning, among the cases 30 persons were fatal. The mean case fatality rate was 27.0%, and most of deaths (93.3%) were the male of above 29 years old. Patient number of below 4 persons per a poisoning accident occupied 75.0% of total outbreaks; 65.8% of total cases; and 66.7% of total deaths) was occurred in the months, November through January. Most of puffer fish poisoning (75.0% of total outbreaks; 68.5% of total cases; and 73.3% of total deaths) were found along the south coastal area of Korea, including Busan, Gyeongsangnam-do, Jeollanam-do and Jeju-do. Over than 80% of puffer fish poisoning outbreaks occurred at fishing boat and home where privately made food was cause, and outbreaks in restaurants accounted for 15.6%. Most commonly implicated foods were Guk, boiled soup with puffer fish meat and spices.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.58-62
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• 2007

Digital communication is important for reliability and mobilization of the multi-channel communication systems. Transmitting and receiving data for the mobilization should be possible in anywhere and in anytime. And this system must be designed light weight small size and low power. One are essential technology for implementing the mobile wireless communication system on the age of ubiquotos. Requirements in constructing such communication field are followings. At first data transmitting and receiving should be carried out by a simple command. Second, the device should be designed as hand-hold type and low power consumption. Third, data communication should be reliable. As one of examples, car to car system which is popular in the market is introduced here, All traffic information in highway is transmitted from one car to another by using this system which can prevent possible traffic accident. This paper shows the design of a digital data communication system with CC1020 chip. This CC1020 makes easy frequency selection and easy switch from the transmit mode to the receive mode by simple setting of a memory register in the chip. The transmit power of this system is designed 10dBm and its communication range is about 100m. The power supplied this system is 3V considered as low power. The sleep mode can be easily entered during transmit mode or receive mode. We shows the program algorithm of CC1020 and interface circuit between MCU and CC1020. We shows the Photo of the CC1020 Module and Atmega128 Module.. We analysed the receiver rate with this system.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.40-47
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• 2017

Dust explosion hazards are always present when combustible dusts are manufactured or handled in the process. However, industries is experiencing difficulty in establishing chemical accident prevention measures because of insufficiency of information on dust explosion characteristics of combustible dust handled in industry. In this study, we investigated experimentally dust explosion characteristics of two kinds of multi-walled carbon nano tubes (MWCNT) different in particle size distribution and examined classification of dust explosion hazardous area for MWCNT manufacturing or handling process by applying the NFPA 499 code. As a result, $P_{max}$, $K_{st}$, LEL, MIE and MIT of MWCNT 1 having $124.2{\mu}m$ median diameter are obtained 6.3 bar, $56bar{\cdot}m/s$, $125g/m^3$, over 1000 mJ, and over $650^{\circ}C$. $P_{max}$, $K_{st}$, LEL, MIE and MIT of MWCNT 2 having $293.5{\mu}m$ median diameter are 6.2 bar, $42bar{\cdot}m/s$, $100g/m^3$, over 1000 mJ, and over $650^{\circ}C$, respectively. MWCNT 1, 2 are not categorized as combustible dust listed in the NFPA 499 Code for classification of dust explosion hazardous area because explosion severity and ignition sensitivity of MWCNT 1, 2 are below 0.35 and 0.01, respectively.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.253-259
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• 2016

Regarding the research on lane recognition, continuous studies have been in progress for vehicles to navigate autonomously and to prevent traffic accidents, and lane recognition and detection have remarkably developed as different algorithms have appeared recently. Those studies were based on vision system and the recognition rate was improved. However, in case of driving at night or in rain, the recognition rate has not met the level at which it is satisfactory. Improving the weakness of the vision system-based lane recognition and detection, applying sensor convergence technology for the response after accident happened, among studies on lane detection, the study on the curve road detection was conducted. It proceeded to study on the curve road detection among studies on the lane recognition. In terms of the road detection, not only a straight road but also a curve road should be detected and it can be used in investigation on traffic accidents. Setting the threshold value of curvature from 0.001 to 0.06 showing the degree of the curve, it presented that it is able to compute the curve road.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.636-644
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• 2015

In this paper, we examined factors that affect the success of a policy on trekking time restriction using questionnaire survey data collected from the visitors of seven national parks where the trekking time restriction policy is in force as of 2014. Results suggest that the trekking time restriction policy has been successfully publicized. In total, 60.7% of the survey respondents were aware of trekking time restrictions in the national parks they were visiting. Using exploratory factor analysis, we identified three latent factors (visitors' careless trekking, park rangers' insufficient management and visitors' unpreparedness) that the visitors perceived the causes of trekking accidents in the national parks. Multiple regression analysis on the three extracted factors and respondents' socioeconomic status shows that the respondents who read information signs in national parks and who judged visitors' careless trekking and visitors' unpreparedness as the causes of trekking accidents tended to agree more with restricting trekking time. These results indicate that visitors who do not agree with the trekking time restriction tend to attribute trekking accidents in national parks not to individual visitors, suggesting that educating visitors is more effective in preventing trekking accidents in national parks than installing and maintaining safety facilities by park rangers.

• Korean Security Journal
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• no.53
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• pp.83-105
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• 2017

The purpose of this study is to identify the problems of In-Flight Security Officer responsible for the security of the aircraft in the situation where Acts of Unlawful Interference in Aircraft shows an increasing tendency and the aircraft security is threatened by the terror threat of IS(Daesh) and to suggests its policy implications. Based on the problems of In-Flight Security Officer system found in the media reports and laws, the US Air Marshal system and the domestic similar system were presented to the In-Flight Security Officer developmental implications. First, it is necessary to revise the "Operational Guidelines for Airline Operators' In-Flight security officer" and the related qualifications to the "National Technical Qualifications" system. Second, the plan to change the national civil servants of In-Flight Security Officer in the aircraft, Third, it is a plan to use the registered security guard system in the aircraft. Although this study has limitations the accessibility of information related to aviation security. But, contributions of this study is that the government's efforts to create the public sector jobs, the "strengthening of public services in the country", "the establishment of national accountability for safety accident prevention and disaster safety management" in the "A five-year plan for Government Operation" that it has a timeliness in that it is together. In addition, since there are not many researches related to In-Flight Security Officer, this study also has another contribution as a basic study of the researchers in the aviation security aircraft in the future.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.399-406
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• 2004

최근 급속한 도시의 팽창과 산업의 발전으로 인하여 가스시설은 급속히 확대되고 있는 실정이다. 이러한 가스시설물의 중요성을 인식하고 많은 도시가스업체에서는 가스관망 시설정보를 전산화하여 항상 최신의 현황을 유지할 수 있는 가스시설물관리시스템을 개발하여 사용하고 있다. 그러나 이러한 시스템은 가스시설물의 현황파악 및 유지관리를 위한 기본적인 기능만을 제공하는 관계로, 가스 누출사고 발생시 정확한 사태의 파악과 함께 신속한 대책 마련을 위한 의사결정 지원이 어려운 실정이다. 따라서 체계적인 가스사고관리를 수행할 수 있는 응용시스템의 필요성이 증대되고 있다. 이러한 시점에서 본 연구에서는 가스사고분석을 신속하고 체계적으로 수행할 수 있는 가스사고관리 적용알고리즘 분석 및 최적의 알고리즘을 정립하여 가스사고관리시스템을 구현하였다. 본 연구를 통한 결과는 1ㆍ2차 차단밸브의 산정이 가능해짐으로써 빈번한 가스 누출사고 발생시 실시간으로 적정대처방안의 제시가 가능하게 되었다. 또한, 누출 최대가스량을 제시함으로써 누출에 대한 피해예상 분석을 위한 정보 제공 및 가스의 신속한 재공급을 위해 필요한 의사결정 지원 정보의 제공이 가능하게 되었다. 아울러, 가스누출사고에 의한 가스공급중단 관로 및 수용가에 대한 속성현황의 파악은 물론 시각적인 도식을 통한 전체적 현황파악이 가능하였다. 이러한 가스사고관리시스템의 개발을 통하여 사고 발생시 신속한 사고방안 제시 및 사고피해의 최소화를 위해 필요한 의사결정 지원 정보의 제공이 가능하게 됨으로써 국민의 안전 및 복지와 도시가스업체의 업무 효율화로 인한 예산절감 효과를 기대할 수 있다. 가시권 분석기능을 이용하여 실제 지형공간상에서 전파경로 손실치를 도시화함으로써 전파관리자가 무선서비스지역 설계, 전파음영지역 판단, 최적 중계기와 기지국 위치 선정에 기여할 것으로 판단된다.하지 않은 지역과 서로 다른 분광특성을 나타내므로 별도의 Segment를 형성하게 된다. 따라서 임상도의 경계선으로부터 획득된 Super-Object의 분광반사 값과 그 안에서 형성된 Sub-Object의 분광반사값의 차이를 이용하여 임상도의 갱신을 위한 변화지역을 탐지하였다.라서 획득한 시추코아에 대해서도 각 연구기관이 전 구간에 대해 동일하게 25%의 소유권을 가지고 있다. ？스굴 시추사업은 2008년까지 수행될 계획이며, 시추작업은 2005년까지 완료될 계획이다. 연구 진행과 관련하여, 공동연구의 명분을 높이고 분석의 효율성을 높이기 위해서 시료채취 및 기초자료 획득은 4개국의 연구원이 모여 공동으로 수행한 후의 결과물을 서로 공유하고, 자세한 전문분야 연구는 각 국의 대표기관이 독립적으로 수행하는 방식을 택하였다 ？스굴에 대한 제1차 시추작업은 2004년 3월 말에 실시하였다. 시추작업 결과, 약 80m의 시추 코아가 성공적으로 회수되어 현재 러시아 이르쿠츠크 지구화학연구소에 보관중이다. 이 시추코아는 2004년 8월 중순경에 4개국 연구팀원들에 의해 공동으로 기재된 후에 분할될 계획이다. 분할된 시료는 국내로 운반되어 다양한 전문분야별 연구에 이용될 것이다. 한편, 제2차 시추작업은 2004년 12월에서 2005년 2월 사이에 실시될 계획이다. 수백만년에 이르는 장기간에 걸쳐 지구환경변화 기록이 보존되어 있는 ？스굴호에 대한