• Title/Summary/Keyword: Safety problem

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An Improved Method for the Evaluation of Load Carrying Capacity of Existing Bridges (교량 구조물의 개선된 내하력 평가기법)

  • Oh, Byung-Whan;Kim, Ki-Su;Shin, Ho-Song;Lee, Woong-Jong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.1 no.1
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    • pp.53-64
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    • 1997
  • Recently, safety evaluation of structures has received great concern in this country. One major problem in safety evaluation is that the results are often quite different depending upon evaluation authority. This is mainly due to arbitrary selection of various modification factors when employing allowable stress method for safety evaluation, The purpose of the present study is, therefore, to establish a rational method to determine the modification factors, especially the stress modification factor and the deterioration modification factor based on visual examination. It is thought that the proposed method yields a rational and consistent result for safety evaluation and may efficiently be used for realistic evaluation of load capacity of bridge structures.

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Development of limit equilibrium method as optimization in slope stability analysis

  • Mendjel, D.;Messast, S.
    • Structural Engineering and Mechanics
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    • v.41 no.3
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    • pp.339-348
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    • 2012
  • The slope stability analysis is usually done using the methods of calculation to rupture. The problem lies in determining the critical failure surface and the corresponding factor of safety (FOS). To evaluate the slope stability by a method of limit equilibrium, there are linear and nonlinear methods. The linear methods are direct methods of calculation of FOS but nonlinear methods require an iterative process. The nonlinear simplified Bishop method's is popular because it can quickly calculate FOS for different slopes. This paper concerns the use of inverse analysis by genetic algorithm (GA) to find out the factor of safety for the slopes using the Bishop simplified method. The analysis is formulated to solve the nonlinear equilibrium equation and find the critical failure surface and the corresponding safety factor. The results obtained by this approach compared with those available in literature illustrate the effectiveness of this inverse method.

Research for the Wear Status and Encourage the Children to Wear Safety Helmets (어린이용 안전모의 착용실태와 착용성 증대 방안을 위한 연구)

  • Song, Rae Ho;Lee, Kang In
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.149-162
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    • 2015
  • This study was conducted on young children safety helmet to prevent risk of head injuries from external shock. Young children helmet shall be easy to wear and use comfortably. But the young children helmet market in domestic has imported dependently and widely variations in quality because the euro product of high priced and the east asia product of low priced are selling at the same time. Therefore, this study surveyed children under 13 years of age and Married people and studies their actual state of wearing. Furthermore, this study is going to propese the improving wearing of helmet and the major points of quality of helmet and the problem by comparing and reviewing regulations of domestic and foreign.

Development of Type 4 Composite Pressure Vessel by using PET Liner for Self-contained Breathing Apparatus (PET 라이너를 적용한 공기호흡기용 타입 복합재료 4 압력용기 개발)

  • Cho, Sung-Min;Lee, Seung-kuk;Cho, Min-sik;Lyu, Sung-ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.164-169
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    • 2018
  • In this study, we solved the human hazard problem of aluminum liner by applying plastic PET liner which is widely used as a material for food and beverage containers in the market. In order to reinforce dome area by using low strength / high elongation plastic liner, The aluminum boss was covered on the plastic liner surface. In order to predict the performance of the developed product, the structural analysis was carried out by applying the three - dimensional laminated solid element, and the soundness of the product was verified through the prototype performance test.

AIMS-MUPSA software package for multi-unit PSA

  • Han, Sang Hoon;Oh, Kyemin;Lim, Ho-Gon;Yang, Joon-Eon
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1255-1265
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    • 2018
  • The need for a PSA (Probabilistic Safety Assessment) for a multi-unit at a site is growing after the Fukushima accident. Many countries have been studying issues regarding a multi-unit PSA. One of these issues is the problem of many combinations of accident sequences in a multi-unit PSA. This paper deals with the methodology and software to quantify a PSA scenarios for a multi-unit site. Two approaches are developed to quantify a multi-unit PSA. One is to use a minimal cut set approach, and the other is to use a Monte Carlo approach.

Validation of UNIST Monte Carlo code MCS for criticality safety calculations with burnup credit through MOX criticality benchmark problems

  • Ta, Duy Long;Hong, Ser Gi;Lee, Deokjung
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.19-29
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    • 2021
  • This paper presents the validation of the MCS code for critical safety analysis with burnup credit for the spent fuel casks. The validation process in this work considers five critical benchmark problem sets, which consist of total 80 critical experiments having MOX fuels from the International Criticality Safety Benchmark Evaluation Project (ICSBEP). The similarity analysis with the use of sensitivity and uncertainty tool TSUNAMI in SCALE was used to determine the applicable benchmark experiments corresponding to each spent fuel cask model and then the Upper Safety Limits (USLs) except for the isotopic validation were evaluated following the guidance from NUREG/CR-6698. The validation process in this work was also performed with the MCNP6 for comparison with the results using MCS calculations. The results of this work showed the consistence between MCS and MCNP6 for the MOX fueled criticality benchmarks, thus proving the reliability of the MCS calculations.

The Study on the Way of Radioactive Waste Disposal in China

  • Keyan Teng;Hao Peng;Caixia Lv;Han Wu
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.4
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    • pp.533-540
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    • 2022
  • Because of the massive development of nuclear power plants in China in recent years, China is facing the challenge of radioactive waste disposal. China has established complete regulatory requirements for radioactive waste disposal, but it also has encountered problems and challenges in low-level radioactive waste disposal in terms of management, selection of disposal facility sites, and implementation of a site selection plan. Three low-level radioactive waste disposal facilities that have been operated in China are described, and their activity limits, locations, and capacities are also outlined. The connotations of "regional" and "centralized" disposal policies are discussed in light of the characteristics of the radioactive waste. The characteristics and advantages of the regional and centralized disposal policies are compared. It is concluded that the regional disposal policy adopted in 1992 can no longer meet the current disposal needs, and China should adopt a combination of the two disposal policies to solve the problem of radioactive waste disposal.

A COMPUTER SIMULATION MODEL AS A MEANS OF EMERGENCY EVACUATION TRAINING FOR CONSTRUCTION PROJECTS

  • Chung-Suk Cho;Dong-Cheol Shin
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.864-868
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    • 2009
  • Fire safety management on any construction site should start with recognizing fire risks in the workplace, understanding the extent of the risks, and proper assessment of the controls necessary to reduce the risks. However, the most important step to prevent fire-related accidents on jobsites is the constant review and monitoring of processes and controls by all individuals involved. This study was conducted to analyze the effectiveness of using computer simulation as an addition to maps or floor plans in safety training and management. Simulex was used on a real project to model various egress routes and to identify potential problem areas of the evacuation strategy. This study highlights the efficacy of simulated emergency evacuation as a training tool that visually shows constantly altering means of egress.

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Development of Open Type Scaffolding Foothold for Material Vertical Transport (자재 수직 운반용 개방형 비계발판 개발)

  • Kim, so-young;Kim, geun-yeong;Jang, Myunghoun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.32-33
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    • 2021
  • When materials are to be transported vertically at the construction site, if the space is small, there is often a precarious situation in which materials are transported outside the scaffold or through the space secured by removing the safety footrest. In addition, if the safety foothold is removed, the reinstallation may not occur due to carelessness of a worker. To solve the problem of this particular case, we have created a safety foothold that is unnecessary to dismantle and can be opened.

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A Random Forest Algorithm-based Accident Prediction to Prevent Marine Pilot Occupational Accidents

  • Gokhan Camliyurt;Won Sik Kang;Daewon Kim;Sangwon Park;Youngsoo Park
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2022.06a
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    • pp.415-416
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    • 2022
  • Marine pilot occupational accidents during transfer to/from the ship are at the top of the agenda after several safety campaigns by IMPA and individual attemptsThere is multiple transfer method for the marine pilot, but a most common way is to use the pilot cutter. This paper aims to predict marine pilot occupational accidents before it occurs by using historical data. Since the problem depends on several variables, this paper develops a model by using the random forest method to predict marine pilot accidents before happening with the random forest method by using RStudio software

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