• Title/Summary/Keyword: Safety criterion

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Validity and Reliability Analysis of Korean Version of Hospital Safety Organization Scale (한국어판 병원 안전조직화 척도의 타당도와 신뢰도 분석)

  • So Yeon Kim;Mikyung Moon
    • Journal of the Korean Society of Safety
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    • v.38 no.1
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    • pp.78-86
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    • 2023
  • In this study, we explored the psychometric properties of the Korean version of the Safety Organization Scale (K-SOS). The SOS is based on the principles of a high-reliability organization and is an effective measure of the self-reported behaviors underlying the safety culture of an organization. We conducted a methodological study to examine the validity and reliability of the 9-item SOS translated into Korean. The data of 108 nurses working in three general hospitals with more than 100 beds located in D City were included. Content validity, construct validity, criterion validity, and reliability were evaluated. The results confirmed that the K-SOS is a unidimensional structure scale. Higher K-SOS scores exhibited a significant correlation with Hospital Survey On Patient Safety Culture, thus indicating the validity of the criterion. The internal consistency of the K-SOS was acceptable. Thus, the K-SOS is a reliable self-report scale for directly measuring the safety behaviors of an organization. The K-SOS can be used to improve patient safety in Korean hospital settings.

An Application of Minimum Strain Energy Density Criterion in Mixed Mode Fatigue Problem (혼합모드 피로문제에서의 최소 변형에너지 밀도기준의 적용)

  • Shim, Kyu-Seok;Koo, Jae-Mean
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.1-7
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    • 2002
  • In this paper, the maximum minimum strain energy density criterion was applied to the mixed mode fatigue test of A5052 H34 alloy. In this study result we can have seen that the authors stress intensity factor for the finite width specimen and method of determining testing load, based on the plastic zone size and the limited maximum stress intensity factor by ASTM STANDARD E-647-95, is useful.

The Evaluation of the Fracture Criterion having an Effect on Crack Extension Simulation for a Thin Sheet (박판시험편의 균열성장 시물레이션에 미치는 파괴기준 평가)

  • 권오헌
    • Journal of the Korean Society of Safety
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    • v.15 no.4
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    • pp.15-19
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    • 2000
  • The exact estimation of the ductile crack growth in a thin sheet would be needed in part of the commercial transport aircraft industry fields. A 2-dimensional elastic plastic finite element analysis was carried out to simulate a stable crack extension in a thin sheet 2024 aluminium alloy. Two kinds of crack modeling were used to evaluate curves of the stable crack extension. And then CTOA(crack tip opening angle) and CTED(crack tip energy density) were calculated in order to determine whether they can be used as useful crack extension criterions in a thin sheet. Results indicate that stable crack extension behaviors were simulated well and CTED is more admirable even though CTOA also is reasonable as a criterion for a stable crack extension in a thin 2024 aluminium alloy sheet.

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Strength Prediction of Bolted Woven Composite Joint Using Characteristic Length (특성 길이를 이용한 평직 복합재 볼트 체결부의 강도 예측)

  • Park Seung-Bum;Byun, Joon-Hyung;Ahn, Kook-Chan
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.8-15
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    • 2003
  • A study on predicting the joint strength of mechanically fastened woven glass/epoxy composite has been performed. An experimental and numerical study were carried out to determine the characteristic length and joint strength of composite joint. The characteristic lengths for tension and compression were determined from the tensile and compressive test with a hole respectively. The characteristic lengths were evaluated by applying the point stress failure criterion to a specimen containing a hole at the center subjected to tensile loading and a specimen containing a half circular notch at the center subjected to compressive load. The joint strength was evaluated by the Tsai-Wu and Yamada-Sun failure criterion on the characteristic curve. The predicted results of the joint strength were compared with experimental results.

Manufacturing Integral Safety Vents in Prismatic Lithium-ion Batteries (직사각형 리튬 이온 전지의 일체형 안전장치 제조 공정에 관한 연구)

  • Kim, J. H.;Lee, K. H.;Lim, Y. J.;Kim, B. M.
    • Transactions of Materials Processing
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    • v.24 no.4
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    • pp.293-298
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    • 2015
  • A safety vent is crucial to protect its user from unpredictable explosions caused by increasing internal pressure of the lithium-ion batteries. In order to prevent the explosion of the battery, a safety vent rupture is required when the internal pressure reaches a critical value. In conventional manufacturing, the cap plate and the safety vent are fabricated separately and subsequently welded to each other. In the current study, a manufacturing process including a backward extrusion and coining process is suggested to produce an integral safety vent which also has the benefit of increasing production efficiency. FE simulations were conducted to predict the rupture pressure and to design the safety vent using a ductile fracture criterion and the element deletion method. The critical value, C, in the ductile fracture criterion was obtained from uniaxial tensile tests with an annealed sheet of 1050-H14 aluminum alloy. Rupture tests were preformed to measure the rupture pressure of the safety vent. The results met the required rupture pressure within 8.5±0.5 kgf/cm2. The simulation results were compared with experimental results, which showed that the predicted rupture pressures are in good agreement with experimentally measured ones with a maximum error of only 3.9%.

Effect of hydraulic distribution on the stability of a plane slide rock slope under the nonlinear Barton-Bandis failure criterion

  • Zhao, Lian-Heng;Cao, Jingyuan;Zhang, Yingbin;Luo, Qiang
    • Geomechanics and Engineering
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    • v.8 no.3
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    • pp.391-414
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    • 2015
  • In this paper, stabilities of a plane slide rock slope under different hydraulic distributions were studied based on the nonlinear Barton-Bandis (B-B) failure criterion. The influence of various parameters on the stability of rock slopes was analyzed. Parametric analysis indicated that studying the factor of safety (FS) of planar slide rock slopes using the B-B failure criterion is both simple and effective and that the effects of the basic friction angle of the joint (${\varphi}_b$), the joint roughness coefficient (JRC), and the joint compressive strength (JCS) on the FS of a planar slide rock slope are significant. Qualitatively, the influence of the JCS on the FS of a slope is small, whereas the influences of the ${\varphi}_b$ and the JRC are significant. The FS of the rock slope decreases as the water in a tension crack becomes deeper. This trend is more significant when the flow outlet is blocked, a situation that is particularly prevalent in regions with permafrost or seasonal frozen soil. Finally, the work is extended to study the reliability of the slope against plane failure according to the uncertainty from physical and mechanics parameters.

Seismic fragility evaluation of the base-isolated nuclear power plant piping system using the failure criterion based on stress-strain

  • Kim, Sung-Wan;Jeon, Bub-Gyu;Hahm, Dae-Gi;Kim, Min-Kyu
    • Nuclear Engineering and Technology
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    • v.51 no.2
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    • pp.561-572
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    • 2019
  • In the design criterion for the nuclear power plant piping system, the limit state of the piping against an earthquake is assumed to be plastic collapse. The failure of a common piping system, however, means the leakage caused by the cracks. Therefore, for the seismic fragility analysis of a nuclear power plant, a method capable of quantitatively expressing the failure of an actual piping system is required. In this study, it was conducted to propose a quantitative failure criterion for piping system, which is required for the seismic fragility analysis of nuclear power plants against critical accidents. The in-plane cyclic loading test was conducted to propose a quantitative failure criterion for steel pipe elbows in the nuclear power plant piping system. Nonlinear analysis was conducted using a finite element model, and the results were compared with the test results to verify the effectiveness of the finite element model. The collapse load point derived from the experiment and analysis results and the damage index based on the stress-strain relationship were defined as failure criteria, and seismic fragility analysis was conducted for the piping system of the BNL (Brookhaven National Laboratory) - NRC (Nuclear Regulatory Commission) benchmark model.

Development of performance assessment criterion for structures of shield TBM tunnel (쉴드 TBM 터널의 구조물 성능 평가 기준 개발)

  • Seong, Joo-Hyun;Lee, Yu-Seok;Hong, Eun-Soo;Byun, Yo-Seph
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.5
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    • pp.553-561
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    • 2015
  • In this study, the performance assessment criterion for reasonable maintenance of shield TBM tunnel was presented. The performance assessment items such as crack, leakage, breakage, spalling, exfoliation/detachment, efflorescence, quality condition, exposure of steel, carbonation, faulting step, bolts condition, drainage condition, ground condition, contact section condition and conduit condition were selected by analyzing domestic and foreign performance assessment criterions and investigating segment lining deterioration cases through the site investigation and in-depth inspection analysis result on the shield TBM tunnel. In addition, the reasonable weight using AHP (Analytic Hierarchy Process) were estimated.

A Study on the PHA of ATP Equipment for the Korean Tilting Train (한국형 틸팅열차 ATP장치 예비위험원분석에 관한 연구)

  • Shin, Duc-Ko;Baek, Jong-Hyen;Lee, Kang-Mi;Kim, Yong-Kyu
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1959-1962
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    • 2009
  • In this paper, we derive the hazard which is a criterion of safety assurance by PHA for the ATP equipped in Korea Tilting Train. The ATP onboard equipment in Korea Tilting Train was introduced as ETCS Level l(which is ETCS specification). Also, the ATP trackside equipment was introduced as a ETCS SRS(System Requirement Specification) 2.2.2 and it has a target for commercial operation in 2009 late. In IEC 62278(EN50126), it recommend of PHA to derive a hazard of target system in concept establishment step and estimate if it can control as a tolerable level and then derive safety case to control the hazard by lifecycle. Therefore, we indicate the hazard using criterion of safety assurance by PHA using FRS (Functional Requirement Specification) 5.0. which is a upper criterion than SRS. The hazard of ATP onboard equipment derived in Korea Tilting Train will be able to use as ATP functional hazards of unified onboard equipment in G7 which is a multiple unit and preliminary hazards of ATP onboard equipment in NEL drived by Korail.

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Technical Criterion of Safety Evaluation of Leakage Preventing Plates for Alleviating Space Shortage Between Chemical Storage Tank and Dike (화학물질 저장 탱크와 방류벽 사이의 공간 부족 개선을 위한 누출 방지판의 안정성 평가 기준)

  • Lee, Eunbyul;Kwak, Sollim;Choi, Youngbo
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.42-50
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    • 2018
  • The Chemical Controls Act strictly regulates for the chemical companies to establish sufficient space between the liquid chemical tank and dike, but facilities already installed suffer from the space shortage between the tank and dike. Installing leakage preventing plates on the dike is considered as one of the economic solutions that can alleviate the space deficiency. However, there is no technical and reasonable criterion for the safety evaluation of the leakage preventing plate on the dike. In order to address this problem, we provide generalized and verified calculating equations that give maximum height and horizontal distance of leakage trajectories. Through the proposed equations, proper heights of the leakage preventing plates on the dike can be easily determined. In this study, new calculating methods are also developed to determine the impact force of the liquid to the leakage preventing plates. In addition, we performed the reactivity experiments between four corrosive liquid chemicals and two stainless steel materials that are candidate substances for the construction of the leakage preventing plate. The results of this study is expected to be applicable as a guideline in the design of safe dike and its leakage preventing plates.