• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.56-64
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• 2014

There were a total of 65 accidents of helicopers between 1990 and 2013. The overall accidents rate has remained around 8 accidents per 100,000 flight hours, and the fatal rate has stayed at about 8 accidents per 100,000 flight hours. In this study, we conduct a series of statistical analyses to investigate the significance of latent failure of groups that operate the helicopter. Analysis of variance demonstrated significant differences in the latent condition score for the 3 groups, with the lower accidents rate groups reporting better scores of latent condition. Results indicated that there are the significant differences of latent condition in accidents between groups of high accidents rate and groups of low accidents rate.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.104-109
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• 2010

The fatality of pedestrian accounts for about 21.2% of all fatality at 2007 year in Korea. In car to pedestrian accident it is very important to inspect the throw distance of pedestrian after collision for exact reconstructing of the accident. The variables that influence on the throw distance of pedestrian can be classified into the factors of vehicle and pedestrian, and road condition. It was simulated by PC-CRASH, a kinetic analysis program for a traffic accident in sedan type vehicle and SPSS program was used for regression analysis. From the results, the throw distance of pedestrian increased with the increasing of vehicle velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and throw distance at the road condition of wet was longer than that at dry condition. Finally, the regression model of sedan type vehicle on the throw distance of pedestrian was as follows; $$dist_i=2.39-0.11offset_i+0.59speed_i-545height_i-0.25walk_i+2.78wet_i+{\epsilon}_i$$.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.493-505
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• 2023

Comprehensive condition monitoring of large industry systems such as nuclear power plants (NPPs) is essential for safety and maintenance. In this study, we developed novel system-scale diagnostic technology based on deep-learning and IR thermography that can efficiently and cost-effectively classify system conditions using compact Raspberry Pi and IR sensors. This diagnostic technology can identify the presence of an abnormality or accident in whole system, and when an accident occurs, the type of accident and the location of the abnormality can be identified in real-time. For technology development, the experiment for the thermal image measurement and performance validation of major components at each accident condition of NPPs was conducted using a thermal-hydraulic integral effect test facility with compact infrared sensor modules. These thermal images were used for training of deep-learning model, convolutional neural networks (CNN), which is effective for image processing. As a result, a proposed novel diagnostic was developed that can perform diagnosis of components, whole system and accident classification using thermal images. The optimal model was derived based on the modern CNN model and performed prompt and accurate condition monitoring of component and whole system diagnosis, and accident classification. This diagnostic technology is expected to be applied to comprehensive condition monitoring of nuclear power plants for safety.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.351-360
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• 2011

In order to reduce the casualties of fishing boats, the author analyzed the fishing boat accident on the 412 cases in Korean maritime safety tribunal for the 2005~2009, and then studied the relation between the weather element and the accidents. According to this studies, the occurring ratio of sea casualty for fishing boat in fog weather was appeared 1 boat per 1.6 days. It means that the restricted visibility condition gives the most influence on the fishing boat accident. The casualties in winter season from November to next January occurred 139(33.7%), and small boats less than 50tons broke out more casualties with 68.4%. From this we can find that small fishing boats are very deeply affected on the sea weather condition. According to the boat types for fishing the casualty of jig boat was ranked first, and collision accident account for first with 77.9% for the types of casualties. As mentioned above, most sea casualties for small fishing boats were resulted from the human factors such as poor watch keeping in invisibility and the bad sea condition, it is necessary for navigation operators and the manager to take more attention to the meteorological factors.

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.113-118
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• 2005

This study delivers the actual condition of investment for industrial accident prevention based on survey of 500 construction sites from 'reports far industry safety and health' published by Korea Occupational Safety & Health Agency (KOSHA). The various research techniques were used such as technical statistic analysis for construction industry, cost comparison of industrial accident prevention and accident loss. A formula was deduced to calculate accident loss and accident frequency by accident prevention cost through regression analysis.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.9-18
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• 2005

This study delivers the actual condition of investment for industrial accident prevention based on survey of 526 construction sites. The various research techniques were used such as technical statistic analysis for construction industry, construction and civil engineering works, cost comparison of industrial accident prevention and accident loss. A formula was deduced to calculate accident loss and accident frequency by accident prevention cost through regression analysis.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.19-30
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• 2005

This study delivers the actual condition of investment for industrial accident prevention based on survey of 526 construction sites. The various research techniques were used such as technical statistic analysis for construction industry, construction and civil engineering works, cost comparison of industrial accident prevention and accident loss. A formula was deduced to calculate accident loss and accident frequency by accident prevention cost through regression analysis.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.56-62
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• 1990

This study is conducted to analyze exact causes of occupational fatalities and results are as follows ： 1) The number of fatalities in establislment which employed less than 50 workers is 605(40.1％ ). Age of sixties and seventies is occupied by 10 percent with there being old-aged trend. Fatal workers who were employed less than 3 months are 39.5 percent and fatal workers who were employed more than 10 years are 11.9 percent. Safety training is necessary for newly recruited and long employed workers. 2) Accident type is, in sequence, fall from elevation, traffic accident, disease, contact with electric current, and hazardous condition is, in order, inadequate guard, hazardous method or procedure, public hazard, and agency of accident is, in sequence, temporary structure/building/structure, powered transport vehicle, passenger vehicle, hoisting or lifting apparatus, and unsafe act is, in order, driving error, failure to secure or warn. 3) The results of cross-tabulation for hazardous condition and accident type is, in sequence, traffic accident by public hazard, fall from elevation by hazardous method or procedure, fall from elevation as well as contact with elctric current by inadequate guard. The result of cross-tabulation for agency of accident and accident type is, in order, fall from elevation by temporary structure/building/structure, traffic accident of passenger vehicle and powered transport vehicle, contact with electric apparatus. The result of cross-tabulation for agency of accident and hazardous condition is, in sequence, public hazard of passenger vehicle, hazardous method or procedure of temporary structure/building/structure, publit hazard of powered transport vehicle, inadequate guard of temporary structure/building/structure. The result of cross-tabulation for unsafe act and accident type is, in sequence, traffic accident by driving error, fall from elevation by inattention to footing or surrounding, contact with electric current by secure or warn.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.632-637
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• 2017

Even though the potential for an accident in nuclear power plants is very low, multiple emergency plans are necessary because the impact of such an accident to the public is enormous. One of these emergency plans involves a robotic system for investigating accidents under conditions of high radiation and contaminated air. To develop a robot suitable for operation in a nuclear power plant, we focused on eliminating the three major obstacles that challenge robots in such conditions: the disconnection of radio communication, falling on uneven floors, and loss of localization. To solve the radio problem, a Wi-Fi extender was used in radio shadow areas. To reinforce the walking, we developed two- and four-leg convertible walking, a floor adaptive foot, a roly-poly defensive falling design, and automatic standing recovery after falling methods were developed. To allow the robot to determine its location in the containment building, a bar code landmark reading method was chosen. When a severe accident occurs, this robot will be useful for accident condition monitoring. We also anticipate the robot can serve as a workman aid in a high radiation area during normal operations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.2
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• pp.12-26
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• 2014

This Study deals with effect of low visibility condition at nighttime on traffic accident. Roads for experiment of this study are Gyeongbu expressway, Seohaean expressway, Yeongdong expressway and Seoul beltway in Gyeonggi province. For this study, I subdivided basic straight section of them into 58 short section. And I analyzed effect of low visibility condition by darkness at nighttime on traffic accident by using 410 traffic accidents between January 1, 2009 and June 30, 2012 on those sections. The Quasi-experimental and negative binomial regression were applied to analyze effect of low visibility condition at nighttime on traffic accident. In this study, I only analyzed visibility difference of daytime and nighttime on traffic accident except other effective variables on traffic accidents. As a result, I have found that it is for low visibility condition at nighttime to have effect on traffic accidents at such specific conditions as Los A speed is maintained in basic straight section of expressway in fine weather. And I tried to do various analysis on types and causes of traffic accidents using the result of analysis.