• Title/Summary/Keyword: The safe factor

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A Study on the Fatigue Strength of the Welds of Membrane Type LNG Tank (멤브레인 방식 LNG탱크 용접부의 피로강도에 관한 연구)

  • 김종호
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.5
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    • pp.542-548
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    • 1997
  • In this study an evaluation method of fatigue strength of membrane type LNG tank is presented with FEM analysis and experimental approach of seam and raised edge welds. The study contains the following : l)FEM analysis of test specimens 2)Fatigue tests of seam and raised edge welds 3)Estimation of cumulative damage factor of the welds on the basis of safe life design concept complying with the rules of classification society 4)Review of the effect of mean stress on the fatigue strength 5)Modelling of fatigue life of the welds which is changeable by weld heights With the results obtained in this study, a model ${\Delta}{\delta}/h^2=0.13553\;{N_{f}}^{-0.3151}$ for seam and raised edge welds having a given weld height is proposed to be useful for designers and inspectors.

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A Study on the Response Modification Factor of Unreinforced masonry Buildings (비보강 조적조 건물의 반응 수정 계수에 관한 연구)

  • 정상훈
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.265-272
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    • 1999
  • there is no earthquake resistant design code for the unreinforced masonary(URM) buildings in Korea. But it does not mean that all URM buldings in Korea is safe under the possible extent of an earthquake. The purpose of this study is in the inelastic analysis of unreinforced masonary walls with many different types of openings and carry out their ductilities an strengths, response modification factor of each wall has been compared and the most appropriate response modification factor for URM building in Korea has been proposed.

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Analysis of Structural Relation between the Shipyard Workers' Ego-state, Safe and Unsafe Behaviors, and Industrial Accidents (조선업 작업자의 자아상태, 안전 및 불안전행동, 산업재해 간의 구조관계 분석)

  • Jeong, Inseok;Jeong, Daekyum
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.101-108
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    • 2018
  • This study was carried out to obtain baseline data on the causes of industrial accidents and their prevention by investigating structural models between the Shipyard workers' egogram ego-states (CP: Critical Parent, NP: Nurturing Parent, A: Adult, FC: Free Child, AC: Adapted Child), safe and unsafe behaviors, and industrial accidents (frequency/severity). In order to achieve this goal, 378 workers from 3 locations of major corporations in Geojedo Island and Ulsan took a questionnaire, which was then analyzed with a structural equation model using the SPSS 23.0 and AMOS 24 statistics package, and the main results of the study are as follows. First, NP and A's ego-states had a positive influence on safe behavior, AC's ego-state had a negative influence on safe behavior, and A's ego-state had the largest influence on safe behavior. Second, CP and AC's ego-states had a positive influence on unsafe behavior, and A's ego-state had a negative influence on unsafe behavior. AC's ego-state had the largest influence on unsafe behavior. Third, safe behavior did not have a significant influence on industrial accidents. However, unsafe behavior had a positive influence on industrial accident frequency and industrial accident severity, both sub-factors of industrial accidents. This study, despite its limitations, such as sampling limitations, has the following significance. First, this study verified that ego-state, a psychological characteristic, is an important factor for predicting unsafe behavior that induces industrial accidents. Second, in order to reduce industrial accidents, there is a need to stimulate the A ego-states, and promote continuous safety management and safety education to neutralize the AC ego-state. Third, previous studies were limited in the area of practical methods for reducing unsafe behaviors, but this study presents practical methods for reducing unsafe behaviors by verifying the structural relationship between safe/unsafe behaviors and industrial accidents by selecting ego-gram ego-states, variable personality theory, as an independent variable.

A Study on the Structural Safety Evaluation of Light Weight Damper for Offshore Rigs (해양시추선용 경량수밀댐퍼의 구조안전성 평가에 관한 연구)

  • Jang, Ji-Seong;Ji, Sang-Won;Han, Seung-Hun
    • Journal of Power System Engineering
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    • v.20 no.6
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    • pp.80-86
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    • 2016
  • In this study, The watertight damper was designed to improve conventional DN 350A butterfly valve. The FSI(Fluid-Structure Interaction) analysis has performed to investigate the safety factor for the watertight damper. When watertight damper of disk was closed, the disk of pressure value is constant. However depending on the opening angle of disk, the flow velocity and pressure are changed. The maximum velocity was appeared at the end of disk on the small outlet area of duct. When the opening angel of disk is $90^{\circ}$, the maximum velocity was appeared at the center of ending disk. So we were found the opening angle of disk is bigger, the flow rate is increased and velocity is also increased from the result of FSI analysis. We can find the least deformation and stress when the opening angel of damper is $90^{\circ}$. When the $45^{\circ}$ opening angle of disk, the largest deformation and stress was found and the minimum safety factor 1.3 was calculated. As a result, we found that the structure of watertight damper is safe enough irrespective of opening angel.

A Study for Algorithm of Safe Transmission in Distributed Network (분산 네트워크에서 안전한 전송을 위한 알고리즘에 관한 연구)

  • Kim, Tae-Kyung;Seo, Hee-Suk;Lee, Dong-Young
    • Journal of the Korea Society for Simulation
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    • v.18 no.1
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    • pp.35-40
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    • 2009
  • The reliability of processing the distributed application becomes more and more important issues in distributed network as the usage of distributed network increases. Because the distributed network applications are processed in the available resources of Internet. It is important factors that the user can efficiently access the available resources and processed results can be delivered to the user of job request. Therefore in this paper, we suggested the survivability factor for sending data safely whether it can be efficiently accessed between the user and available resource which processes the distributed application. And evaluated the performance of the suggested factor using the data transmission time. Also we suggested the transmission algorithm for safe transmission using the survivability factor.

A Study on the Design Improvement and Information Service of Bicycle Road Considering Environmental Factor (주변 환경요소를 고려한 자전거 도로 설계 개선 및 정보제공에 관한 연구)

  • Choi, Byoung-Gil;Park, Hong-Ki;Na, Young-Woo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.1
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    • pp.11-20
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    • 2011
  • This study aimed to devise the method to construct safe and convenient bicycle road by considering the peripheral environmental factor related to using bicycle. Analyzing the existing design of bicycle road and construction case, this study established the method to design bicycle road that reflects site condition and presented the optimal design method for each type of bicycle road to construct safe and convenient bicycle road by analyzing the type of traffic accident for each type of bicycle road, surveying present situation and local survey. It was found that the optimum design of bicycle road for specification, width, curve radius, ascending slope, etc in consideration of peripheral environment and separating traffic between users of traffic means should be done by installing safety sign, safe facilities and separation facilities to design safe bicycle road. Further, the minimum traffic space of bicycle users and connection between bicycle roads should be ensured to design safe bicycle road. It is judged that information related to safety and convenience of bicycle road such as slope, route information, location of convenience facilities, information to the public traffic should be provided so as to activate the users of bicycle.

A Study on the Architectural Planning of the Refuge Areas in Geriatric Hospitals Considering Horizontal Evacuation of the Elderly (노인요양병원에서 고령자의 수평 피난을 고려한 대피공간의 건축계획에 관한 연구)

  • Kim, Mijung;Kweon, Jihoon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.3
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    • pp.7-15
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    • 2023
  • Purpose: This study was conducted with the aim of presenting spatial planning directions for evacuation spaces based on an analysis of the performance of horizontal evacuation during the early stages of fire incidents in a geriatric hospital. Methods: Based on a review of previous studies, the research model was designed by establishing occupancy conditions, evacuation, and fire scenarios. The analysis model was developed by considering vulnerable areas in terms of evacuation movement and analyzing the results of evacuation performance. Furthermore, the study analyzed the improvement in evacuation performance by arranging refuge areas. Results: The results of the study are as follows. Firstly, vulnerability spots were identified in terms of evacuation performance by schematizing Required Safe Egress Time, Available Safe Egress Time, and their differences. Secondly, the Required Safe Egress Time in the adjacent public spaces along the escape routes of occupants was found to be higher compared to the Available Safe Egress Time. Thirdly, the results of the correlation analysis between the difference in Available Safe Egress Time and Required Safe Egress Time during the early stages of a fire, as well as their constituent factors, demonstrated that user congestion is a more significant factor in compromising evacuation safety than the physical changes in the fire condition. Fourthly, the analysis of evacuation time was conducted by designating refuge areas where occupants can evacuate within a sufficient timeframe. This led to a decrease in the Required Safe Egress Time. Implications: This study is expected to be used as data on the direction of evacuation space planning to improve the evacuation performance of Geriatric Hospital.

Strategic Action Plan for Companies to Supply Safe Products Using AHP Technology (AHP를 활용한 안전한 제품을 공급하기 위한 기업의 전략적 실행방안)

  • Seo, JunHyeok;SungMin, Bae
    • Journal of Korean Society for Quality Management
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    • v.50 no.4
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    • pp.635-646
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    • 2022
  • Purpose: In this study, the detailed implementation plan for product safety evaluation and management suggested by KS A ISO 10377 to reduce the risk of harm to consumers and users is presented so that companies can strategically implement it. Methods: In order to achieve the purpose of this study, the upper elements and detailed execution plans shown in KS A 10377 are classified into hierarchies and set as a decision hierarchy. A pairwise comparison is performed to derive it. Results: Among the top factors, 'design safety (D)' was the most important factor, with 0.314. Therefore, ensuring safety in the design stage that can prevent defects in advance is the most important action plan for companies to supply safe products. Conclusion: The results of this study, it is intended to help companies and related organizations more easily understand and continuously apply KS A ISO 10377.

A Study on the Application of Variable Safe-Guard Ring for the Ship Collision Avoidance in Shallow Water (천수역에서 충돌회피를 위한 가변안전경계영역 적용에 관한 연구)

  • Yang, Hyoung-Seon;Ahn, Young-Sup
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.14 no.2
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    • pp.157-162
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    • 2008
  • The ship's maneuverability is the important factor to avoid ship's collisions. The ship's maneuverability is usually measured in a deep water, and the turning ability is decreased and the course stability is improved in a shallow water. The variation of the turning ability could cause the risk of collision. In this paper, we proposes application technique of Variable Safe-Guard Ring to consider the shallow water effect and to be simple to estimate the grade of collision risk simultaneously. Through the mathematical simulation, the availability of new method was varified. Therefore this method is expected enough to support a maneuver for collision avoidance.

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The comparison of provision of risk information between employees with labour union and non labour union (노동조합 유무에 따른 위험정보 제공수준 차이 분석)

  • Cho, Hm Hak;Rhee, Kyung Yong;Kim, Young Sun
    • Journal of the Korea Safety Management & Science
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    • v.16 no.4
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    • pp.257-262
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    • 2014
  • Risk information may be one of the most important factor for worker's safe behavior because that safe behavior can be oriented by attitude based on risk information. Traditionally KAP(knowledge, attitude and practice) model was useful frame for the change of human behavior. Knowledge is formed by information through experience and education. Worker's health may be prevented by his or her own active safe behavior based on risk information. This paper is to investigate the effect of labor union on the provirion of risk information by labor union. Data for analysis is the third Korean Working Conditions Survey done by Occupational Safety and Health Research Institute in 2011. The sample size is 50,032 economic active person surveyed by household interview survey with structure questionnaire by trained interviewer. The difference of risk information provision among employees was tested by mean difference test. The level of risk information of employees of companies with labor union is higher than that with non labour union. This paper has some implication for the promotion of safe behavior of employees through risk information provision mediated by labor union. Some limitation of this study may be considered because of using the cross sectional survey data.