• Title/Summary/Keyword: Safety problem

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Development of a Type 4 Composite Cylinder for Self-contained Breathing Apparatus (공기호흡기용 타입 4 복합재료 용기 개발)

  • Cho, Sung-min;Kim, Da-eun;Seong, Hye-jin;Ko, Young-kyu;Kim, Hong-chul;Lee, Kang-ok;Jo, Min-sik;Lyu, Sung-ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.12
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    • pp.1-6
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    • 2019
  • Aluminum liners used in cylinders are hazardous for human health. In this study, we use a plastic PA liner inside cylinders to solve this problem. Plastic PA liners are widely used in the manufacturing industry in the production of food and beverage containers. We covered the aluminum boss with a plastic liner material and wound the composite fibers over the liner material. To reinforce the dome area, we used low strength / high elongation plastic liner. To predict the performance of the developed product, we conducted structural analyses utilizing the 3D laminated solid element. We verified the soundness of the product by testing the prototype.

A Study on the Improvement of Classification of Explosion Hazardous Area using Hypothetic Volume through Release Characteristic (누출특성을 통한 폭발위험장소 선정방법의 개선에 대한 연구)

  • Kim, Dae-Yeon;Chon, Young-Woo;Lee, Ik-Mo;Hwang, Yong-Woo
    • Journal of the Korea Safety Management & Science
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    • v.19 no.2
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    • pp.31-39
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    • 2017
  • Classify of explosion hazardous areas must be made at the site where flammable materials are used. This reason is that it is necessary to manage ignition sources in of explosion hazardous areas in order to reduce the risk of explosion. If such an explosion hazard area is widened, it becomes difficult to increase the number of ignition sources to be managed. The method using the virtual volume currently used is much wider than the result using CFD(Computational Fluid Dynamics). Therefore, we tried to improve the current method to compare with the new method using leakage characteristics. The result is a realistic explosion hazard if the light gas is calibrated to the mass and the heavy gas is calibrated to the lower explosion limit. However, it is considered that the safety factors should be taken into account in the calculated correction formula because such a problem should be considered as a buffer for safety.

A Study on the Development of Industrial Robot Workplace Safety System (산업용 로봇 작업장 안전시스템 개발에 대한 연구)

  • Jin-Bae Kim;Sun-Hyun Kwon;Man-Soo Lee
    • Journal of the Korea Safety Management & Science
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    • v.25 no.3
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    • pp.17-22
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    • 2023
  • As the importance of artificial intelligence grows rapidly and emerges as a leader in technology, it is becoming an important variable in the next-generation industrial system along with the robot industry. In this study, a safety system was developed using deep learning technology to provide worker safety in a robot workplace environment. The implemented safety system has multiple cameras installed with various viewing directions to avoid blind spots caused by interference. Workers in various scenario situations were detected, and appropriate robot response scenarios were implemented according to the worker's risk level through IO communication. For human detection, the YOLO algorithm, which is widely used in object detection, was used, and a separate robot class was added and learned to compensate for the problem of misrecognizing the robot as a human. The performance of the implemented system was evaluated by operator detection performance by applying various operator scenarios, and it was confirmed that the safety system operated stably.

Extension of IFC information Modeling for Fire Safety based on WBS (작업분류체계 기반 소방 객체 IFC 정보 모델링 확장 방안 연구)

  • Won, Junghye;Kim, Taehoon;Choo, Seoungyeon
    • Journal of KIBIM
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    • v.13 no.2
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    • pp.37-46
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    • 2023
  • The main objective of this study is to propose a method to enhance building safety using the Industry Foundation Classes (IFC) schema in Building Information Modeling (BIM). To achieve this goal, a fire object relationship diagram is created by using the Model View Definition (MVD) and Property Set (Pset) methodology, as well as the Work Breakdown Structure (WBS) based object relationship analysis. The proposed method illustrates how to represent objects and tasks related to fire prevention and human safety during a building fire, including variables that are relevant to these aspects. Furthermore, the proposed method offers the advantage of considering both the IFC object hierarchy and the project work hierarchy when creating new objects, thereby expanding the attribute information for fire safety and maintenance. However, upon confirmation via an IFC viewer after development, a problem with the accuracy of mapping between attributes and objects arises due to the issue of proxy representation of related object information and newly added object information in standard IFC. Therefore, in future research, a mapping method for fire safety objects will be developed to ensure accurate representation, and the scope of utilization of the fire safety object diagram will be expanded. Furthermore, efforts will be made to enhance the accuracy of object and task representation. This research is expected to contribute significantly to the technological development of building safety and fire facility design in the future.

Vital Area Identification Rule Development and Its Application for the Physical Protection of Nuclear Power Plants (원자력발전소의 물리적방호를 위한 핵심구역파악 규칙 개발 및 적용)

  • Jung, Woo Sik;Hwang, Mee-Jeong;Kang, Minho
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.160-171
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    • 2017
  • US national research laboratories developed the first Vital Area Identification (VAI) method for the physical protection of nuclear power plants that is based on Event Tree Analysis (ETA) and Fault Tree Analysis (FTA) techniques in 1970s. Then, Korea Atomic Energy Research Institute proposed advanced VAI method that takes advantage of fire and flooding Probabilistic Safety Assessment (PSA) results. In this study, in order to minimize the burden and difficulty of VAI, (1) a set of streamlined VAI rules were developed, and (2) this set of rules was applied to PSA fault tree and event tree at the initial stage of VAI process. This new rule-based VAI method is explained, and its efficiency and correctness are demonstrated throughout this paper. This new rule-based VAI method drastically reduces problem size by (1) performing PSA event tree simplification by applying VAI rules to the PSA event tree, (2) calculating preliminary prevention sets with event tree headings, (3) converting the shortest preliminary prevention set into a sabotage fault tree, and (4) performing usual VAI procedure. Since this new rule-based VAI method drastically reduces VAI problem size, it provides very quick and economical VAI procedure. In spite of an extremely reduced sabotage fault tree, this method generates identical vital areas to those by traditional VAI method. It is strongly recommended that this new rule-based VAI method be applied to the physical protection of nuclear power plants and other complex safety-critical systems such as chemical and military systems.

Feasibility analysis of RPSD(Rope type Platform Safe Door) on the simulation (시뮬레이션을 통한 로프타입 상하개폐식 승강장 안전문 적용성 검토)

  • Kang, Hee-Chan;Kim, Hyun;Chung, Younshik
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.2
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    • pp.22-29
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    • 2013
  • The platform safety door is difficult to install in platform because the doors of railway vehicles and existing Passenger Safety doors should be alined. To be able to solve this problem, we propose the use of Rope Type Platform Safe Door (RPSD) which is a vertically retractable platform that is designed to close from top to bottom. This platform has installed safety gate pillars at intervals of 20-40 m which accommodates different types of train regardless of train length, gate opening and location. In this paper, we reviewed the application of existing PSD and RPSD in various train stops in Seoul Gyeongbu Line platform. The results of the review showed that the existing PSD may cause problem in construction, safety and cost efficiency. The use of RPSD however shows that minimal problems will be encountered.

A Methodology to Provide the Criterion for the Seakeeping Performance of a Fore-Bridge-Ship in Rough Seas - The Problem on the Application of the Past Deckrwetness Criterion Based on the Accident of a Fore-Bridge-Ship - (황천항해중인 선수선교선의 내항성능평가기준 설정 방안에 관한 연구 - 해난사고 실례를 통한 갑판침수 평가기준치 설정에 대한 개선방안 고찰 -)

  • 공길영;김철승
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.7 no.3
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    • pp.17-28
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    • 2001
  • The wheelhouse front glass of a Fore-Bridge-Ship (Ro-Ro Ship) was broken by the shipping of water in rough seas, and then the flooding of seawater into the wheelhouse caused the uncontrollable condition of the ship. The hull which was entered into the floating condition rolled severely, and the heavy rolling caused secondary damage such as the collapse of a lot of cargo. It was an incredible accident because the height of bow freeboard was about 2.5 times higher than the standard height of minimum bow freeboard regulated by the International Load Line Convention(1966). And it would be also difficult for navigators to imagine a great deal of seawater flooding into the wheelhouse because the front glass was positioned at about 20m height above the sea surface. In this paper, we carried out the evaluation for the safety navigation of the Fore-Bridge-Ship numerically against ship's speed and encountering angle to the wave in each sea state of rough sea, by using the integrated seakeeping performance index (ISPI) which is able to evaluate synthetically the safety operation of ships. And then the problem on the application of the past criteria proposed as the safety navigation of a merchant ship was clarified by inquiring the dangerousness of the shipping of water at her bow deck, which caused the breakage of the wheelhouse front glass.

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Computer Simulation for Working Condition of Undergroundwork Using TOP DOWN Technique (TOP DOWN 지하공사의 작업환경체크 컴퓨터시물레이션에 관한 기초적 연구)

  • 고성석;손기상;심경수
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.96-105
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    • 1995
  • The better industry develops, the more spaces need but in the limited area. Most building become larger and more complicated if the more spaces need in the constant area. And this leads to do underground work in long period generally six(6) months for 6 basement stories due to the selection of TOP DOWN technique. Working environment in this underground area can be problems and should not be overlooked, because air quality in underground spaces become quickly worse. Recently, department name to control construction safety has been changed to ENVIRONMENT & SAFETY TEAM from SAFETY TEAM. This means that it is very important to control against environmental condition at site so much. Overall construction work as well as underground work should conform to the requirement of working environment, particularly against inhabitants around the construction area. Strut protection, one of earth protection method, in case to 40m long strut may become weaker due to thermal stress or its longitudinally compressive strain and the another one, earth anchor protection may not be applied to the site In case of encroaching on vertical underground borderline because of regulation to prohibit it. It is necessary that TOP DOWN technique should be introduced in order to solve the external and internal problem of the site such as difficulty level of the work, potential danger with excavating depth, and shortening workperiod. It is needed that improving way of working condition should be shown and simplified computer simulation program should be also provided for checking pollution level & ventilation, excluding of lighting problem here. Results measured with conformance to the Regulation for Working Environment Measurement, enforced by Ministry of Labor have been applied to the computer program developed here. Sample air taken at unit workplace which was considered as exposing condition of pollutant at breathing point and within a range of behavior of the workers, Identified exposing group in underground work, using Moded Flow Life Finally, three types of ventilation system, type I with blower & ventilator, type II natural supply with mechanical ventilation system, and type I mechanical ventilation with Drivent Fan Unit System are selected for this study.

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A Study on the Development of a Traffic Accident Ratio Model in Foggy Areas (안개지역의 교통사고심각도 모형개발에 관한 연구)

  • Lee, Soo-Il;Won, Jai-Mu;Ha, Oh-Keun
    • Journal of the Korean Society of Safety
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    • v.23 no.6
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    • pp.171-177
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    • 2008
  • As the risk of traffic accidents caused by mists emerged as a social problem, recently safety facilities to be prepared for mists are being actively installed when designing roads. But in some part, the facilities are being installed imprudently without analyzing the extent of occurrences of mists that would increase the risk of traffic accidents and appropriate countermeasures against the occurrences of mists are not being suggested. For that reason, in this study, first questionnaire surveys were executed on road users in order to draw the factors affecting the traffic accidents caused by mists, a mist traffic accident predicting model was developed and an accident seriousness determining model that can determine accident seriousness was developed. In this way, by extracting major factors affecting mist traffic accidents to grasp risk factors in roads to be caused by mists, safety of roads can be enhanced and traffic accidents in road operations can be decreased. As the affecting factors influencing mist traffic accidents, were extracted sightable distances, durations of mists and whether daytime or nighttime as major factors and the plan to install the facilities for the prevention of mist traffic accidents was suggested to prevent the traffic accidents to be caused by those factors and also the plan to operate roads considering sightable distances was suggested to solve the problem of insufficient sightable distances to be caused by mists was suggested. It is judged that the road safety in the areas where mists occur can be improved through foregoing methods.

An improved regularized particle filter for remaining useful life prediction in nuclear plant electric gate valves

  • Xu, Ren-yi;Wang, Hang;Peng, Min-jun;Liu, Yong-kuo
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2107-2119
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    • 2022
  • Accurate remaining useful life (RUL) prediction for critical components of nuclear power equipment is an important way to realize aging management of nuclear power equipment. The electric gate valve is one of the most safety-critical and widely distributed mechanical equipment in nuclear power installations. However, the electric gate valve's extended service in nuclear installations causes aging and degradation induced by crack propagation and leakages. Hence, it is necessary to develop a robust RUL prediction method to evaluate its operating state. Although the particle filter(PF) algorithm and its variants can deal with this nonlinear problem effectively, they suffer from severe particle degeneracy and depletion, which leads to its sub-optimal performance. In this study, we combined the whale algorithm with regularized particle filtering(RPF) to rationalize the particle distribution before resampling, so as to solve the problem of particle degradation, and for valve RUL prediction. The valve's crack propagation is studied using the RPF approach, which takes the Paris Law as a condition function. The crack growth is observed and updated using the root-mean-square (RMS) signal collected from the acoustic emission sensor. At the same time, the proposed method is compared with other optimization algorithms, such as particle swarm optimization algorithm, and verified by the realistic valve aging experimental data. The conclusion shows that the proposed method can effectively predict and analyze the typical valve degradation patterns.