• Title/Summary/Keyword: Analyzing accidents

Search Result 560, Processing Time 0.026 seconds

Analyzing Chemical Reaction Routes of Explosion by a Mixed Acid - Focusing on Chemical Carriers - (혼산에 의한 폭발사고의 화학반응 경로 분석 - 화학물질 운반 선박을 중심으로 -)

  • Kang, Yu Mi;Yim, Jeong-Bin
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.6
    • /
    • pp.661-668
    • /
    • 2017
  • The purpose of this study is to analyze the chemical reaction pathway for explosion accident of mixed cargo. The analysis used a structural scenario using event-tree analysis. Structural scenarios were constructed by estimating various chemical reaction paths in the content of the mixed cargo accident recorded in the written verdict. The analytical method was applied to three kinds of analysis: chemical analysis based on chemical theory, quantitative analysis using chemical reaction formula, and probabilistic analysis through questionnaire. As a result of analysis, the main pathway of the accident occurred in three ways: the path of explosion due to the reaction of concentrated sulfuric acid with water, the path of explosion due to the reaction of metal and mixed acid, and the path of explosion by synthesizing with special substances. This result is similar to the path recorded in the validation, and it leads to thar the proposed path analysis method is valid. The proposed method is expected to be applicable to chemical reaction path estimation of various chemical accidents.

The Relationship between Cyberbullying Victimized Experience and Emotional Behavior of Middle School Students (중학생의 사이버불링 피해 경험과 정서행동과의 관계)

  • Oh, Tae-Kon
    • Journal of the Korea Society of Computer and Information
    • /
    • v.18 no.12
    • /
    • pp.207-215
    • /
    • 2013
  • The general opinion about the notion of cyberbullying hasn't existed yet, but in related laws it is defined as the entire behavior causing the counterpart to suffer the pain by continuously and repeatedly psychologic offending toward specific students with information and telecommunication products such as the Internet and mobile phones, and spreading the private information or false facts related with specific students. Recently a number of accidents related with abuse of cyberbullying are being broadcast on a variety of mass media, and the argument about the severity and countermeasures against cyberbullying is moving onward. This study has a purpose as suggesting the practical alternatives to prevent cyberbullying victim of middle school students by arguing cyberbullying of middle school students and analyzing the relationship between the general features such as victimized experience and frequency and the emotional behaviors according to victimized experience. As the result of this study, cyberbullying victimized experience has a significant effect on the emotional behavior such as depression, aggression, and academic stress. As political implication, this study suggests the practical alternatives to prevent cyberbullying of middle school students based on the analysis result.

Development of a CCTV Based Smart Safety Management System in Thermal Power Plants (석탄발전산업을 위한 지능형 CCTV 기반 스마트안전관리시스템 개발 연구)

  • Song, Ho Jun;Gao, Jianxi;Shin, Wan Seon
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.44 no.3
    • /
    • pp.50-63
    • /
    • 2021
  • There has been a steady rate of accident in Coal Thermal Power Plants which have relatively higher chance of mortality. However, neither the systematic view of safety management nor the methodology such as safety factors or system requirements are yet to be studied in detail. Therefore, this study aims to propose a methodology to preemptively deal with safety issues and to secure fact focused responsibility in safety. It consists of two main parts. First, the Safety Measurement Index(SMI) with total 50 factors is proposed by analyzing the key factors that contribute to safety accidents based on failure mode and effect analysis (FMEA) and quality function deployment (QFD). To analyze the safety requirements, index presented by major countries and organizations are discussed. Second, main features of intelligent CCTV are studied to determine their relative importance for the framework of Smart Safety Management System (SSMS). Main features are discussed with four technological steps. Also, QFD was held to analyze to analyze how key technologies deal with Quality Measurement Index(QMI). The research results of this study reveal that scientific approaches could be utilized in integrating CCTV technologies into a smart safety management system in the era of Industry 4.0. Moreover, this reasearch provides an specific approach or methodology for dealing with safety management in Coal Thermal Power Plant.

A Study on the Stern Bearing Damage and Shaft Alignment for 37K DWT Product/Chemical Tanker (37K DWT 석유화학제품 운반선의 선미관 베어링 발열 사고 및 축계정렬에 대한 연구)

  • Park, Geumsung;Koh, Changik;Chung, Jaewook;Nam, Gunsik;Chae, Junsik
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.58 no.2
    • /
    • pp.97-104
    • /
    • 2021
  • Together with the emerging of the Eco-ship, the application of large-diameter and high-efficiency propeller required more careful attention than before in the design of the shafting system. After the adoption of Environmentally Acceptable Lubricants (EAL) to the stern tube lubrication oil, a number of aft stern tube bearing accidents have been reported, and a variety of institutions have actively conducted research on the cause relationship. This study attempted to find the cause of the accident by measuring the alignment of the shafting system of a medium-sized product/chemical tanker with aft stern tube bearing damage and analyzing the reaction force of each bearing. In addition, a reasonable solution to the correction of the shaft alignment was suggested and the feasibility was reviewed. Through various measured data and analysis, the actual installation of shafting system was slightly different from the design drawing condition, but it was found that each bearing load distribution was within the allowable range. Therefore, it was confirmed that the cause of this accident was due to the dissatisfaction the misalignment slope of aft stern tube bearing rather than the effect of the bearing overload. As a solution to this cause, countermeasures such as double slope were suggested in the aft stern tube bearing, and the characteristics of EAL also seem to have an indirect effect.

Quality Analysis for the Data Distribution Service of the Real-time Integrated Railway Safety Monitoring and Control System (실시간 철도안전 통합 감시제어시스템의 데이터 분산 서비스 품질 적합성 분석)

  • Kim, Sang Ahm;Kim, Seon Woo
    • Journal of The Korean Society For Urban Railway
    • /
    • v.6 no.4
    • /
    • pp.351-361
    • /
    • 2018
  • In this paper, we analyse DDS(Data Distribution Service) QoSs(Quality of Services) with experiments, which can control the network transmission quality provided by 'Object Management Group' DDS standard to satisfy the data transmission quality requirements of 'Real-time integrated railway safety monitoring and control system(RIRSMCS)'. 'RIRSMCS' is a system for collecting and analyzing data from various sensors at a railway field to predict and prevent the risk of potential railway accidents. Data transmission quality should be ensured for transmitting the collected data in real-time, accurately and stably for this system. Experimental results show that it is possible to ensure real-time, accurate and stable data transmission for monitoring and control of railway safety using DDS QoS.

The Relationship Study between Cumulative Fatigue and Stress of Seafarers by Evaluating Autonomic Nervous Functions and Survey Studies (선원의 자율신경 기능평가에 의한 누적피로도 및 스트레스와 조사연구 사이의 관련성 연구)

  • Kim, Byeongjo;Lee, Junghun;Lee, Sookyoung;Kwon, Haeyeon;Kwon, Youngtae;Park, Yongsun;Chae, Byeonggeun
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.6 no.4
    • /
    • pp.1-13
    • /
    • 2018
  • Purpose : The purpose of this study has been performed to find the relationship between seafarers' cumulative fatigue and stress by evaluating autonomic nervous functions and the results of surveys conducted using questionnaires. Methods : The subjects were seafarers working on various ships (home trade ships) of South Korea, who were healthy adults without any diseases, as confirmed through preliminary surveys were recruited through simple random sampling. A device that measures autonomic nervous functions by analyzing heart rate variability, which is also used often in clinical diagnoses and studies at universities, university hospitals, and general hospitals was used to measure the seafarers' cumulative fatigue and stress. Pearson's correlation analyses were also conducted to test the relationship between cumulative fatigue and stress measured by evaluating autonomic nervous functions and the results of surveys conducted with questionnaires. Results : There was no correlation between mean cumulative fatigue measured for each ship type and seafarers position through autonomic nervous functions evaluation and fatigue severity scale (FSS). There also was no correlation between the mean levels of stress measured for each ship type and seafarers position through autonomic nervous functions evaluation and survey scores of Korean occupational stress scale (KOSS). Conclusion : Therefore, in order to prevent man-made accidents in the sea among seafarers working with irregular port entry/departure schedules and under environments involving continued vibration, noises, and shaking, it is necessary to analyzed cumulative fatigue and stress scientifically and objectively, such as through autonomic nervous functions evaluation rather than through surveys.

Investigation of the LPG Gas Explosion of a Welding And Cutting Torch at a Construction Site

  • Lee, Su-kyung;Lee, Jung-hoon;Song, Dong-woo
    • Korean Chemical Engineering Research
    • /
    • v.56 no.6
    • /
    • pp.811-818
    • /
    • 2018
  • A fire and explosion accident caused by a liquefied petroleum gas (LPG) welding and cutting torch gas leak occurred 10 m underground at the site of reinforcement work for bridge columns, killing four people and seriously injuring ten. We conducted a comprehensive investigation into the accident to identify the fundamental causes of the explosion by analyzing the structure of the construction site and the properties of propane, which was the main component of LPG welding and cutting work used at the site. The range between the lower and upper explosion limits of leaking LPG for welding and cutting work was examined using Le Chatelier's formula; the behavior of LPG concentration change, which included dispersion and concentration change, was analyzed using the fire dynamic simulator (FDS). We concluded that the primary cause of the accident was combustible LPG that leaked from a welding and cutting torch and formed a explosion range between the lower and upper limits. When the LPG contacted the flame of the welding and cutting torch, LPG explosion occurred. The LPG explosion power calculation was verified by the blast effect computation program developed by the Department of Defense Explosive Safety Board (DDESB). According to the fire simulation results, we concluded that the welding and cutting torch LPG leak caused the gas explosion. This study is useful for safety management to prevent accidents caused by LPG welding and cutting work at construction sites.

Development of Disaster Safety Program for Small-sized Workplaces and Its Introduction to Occupational Safety&Health Act: Focusing on Fire, Explosion and Chemical Spill (소규모 사업장 재난안전 프로그램 개발 및 산업안전보건법에의 도입방안: 화재, 폭발, 약품 누출을 중심으로)

  • Ko, Seung-cheol;Eum, Tae-Soo;Song, Chang-Geun
    • Journal of Convergence for Information Technology
    • /
    • v.11 no.7
    • /
    • pp.84-90
    • /
    • 2021
  • 98.8% of accidents occurring in domestic companies are concentrated in small-sized workplaces with fewer than 50 employees. Therefore, this study developed a disaster safety program that can be implemented by small and medium-sized enterprises by comparing and analyzing the safety management system actively used with the laws and regulations related to industrial safety and facilities. The disaster and safety program included the scope of application, organizational structure, risk assessment, emergency response system, education and training, safety equipment provision and program evaluation, and detailed preparation methods and procedures for each item. In addition, items to be aware of when operating a disaster safety program and operational strategies were presented. After that, it was proposed to introduce the research results into the Occupational Safety and Health Act.

A study on the definition and development direction of manual therapy (도수치료의 정의에 대한 고찰 및 발전 방향에 관한 연구)

  • Park, Jong Hang;Park, Hyun Sik;Shin, Young Il;Lee, Ho Jong
    • Journal of Korean Physical Therapy Science
    • /
    • v.29 no.1
    • /
    • pp.1-14
    • /
    • 2022
  • Background: The legal and academic definitions of manual therapy in domestic and foreign countries are reviewed, and problems and improvement plan of manual therapy are established through comparative analysis of the current status and system of manual therapy in Korea and abroad. Design: Review. Methods: In this study, the development direction of manual therapy in Korea was derived by analyzing the definition, application status, and service system of domestic and foreign manual therapy. Results: Firstly, it lays the foundation for a more comprehensive national health promotion by solving problems arising from the current unclear definition of manual therapy. Secondly, the subject of manual therapy is a physiotherapist but the subject of claiming non-benefit costs is a doctor, moreover illegal manual therapy by an unqualified or non-professional who is not a physiotherapist is being carried out in the medical field. Thirdly, in order to provide quality physiotherapy services (manual therapy) under a cooperative relationship between medical staff and physiotherapists, it is appropriate that physiotherapist have a clear "prescription" or "request" by a doctor. Fourth, there is no provision for the preparation of medical records in the current Medical Technicians Act, and this causes safety accidents of patients during manual treatment. Conclusion: As described above, the current manual therapy in Korea is being performed indiscriminately without a clear interpretation, resulting in various problems. I think it is necessary to lay the foundation for institutional and legal re-establishment of manual therapy through additional research on manual therapy in the future.

Driver Drowsiness Detection System using Image Recognition and Bio-signals (영상 인식 및 생체 신호를 이용한 운전자 졸음 감지 시스템)

  • Lee, Min-Hye;Shin, Seong-Yoon
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.26 no.6
    • /
    • pp.859-864
    • /
    • 2022
  • Drowsy driving, one of the biggest causes of traffic accidents every year, is accompanied by various factors. As a general method to check whether or not there is drowsiness, a method of identifying a driver's expression and driving pattern, and a method of analyzing bio-signals are being studied. This paper proposes a driver fatigue detection system using deep learning technology and bio-signal measurement technology. As the first step in the proposed method, deep learning is used to detect the driver's eye shape, yawning presence, and body movement to detect drowsiness. In the second stage, it was designed to increase the accuracy of the system by identifying the driver's fatigue state using the pulse wave signal and body temperature. As a result of the experiment, it was possible to reliably determine the driver's drowsiness and fatigue in real-time images.