• Title/Summary/Keyword: 안전계수(safety factor)

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Standardization of Safety Factors of Corrugated Fiberboard Containers for Selected Agricultural Products (과채류 포장용 골판지 상자의 안전계수 표준화)

  • Seong, Haeng-Ki;Kim, Young-Chul;Hwang, Dae-Sung;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.13 no.2
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    • pp.115-127
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    • 2011
  • The aim of this study was to develop a standard to estimate safety factors of corrugated fiberboard containers used for agricultural products. This study is limited to fresh agricultural products packaged in the corrugated fiberboard containers and further work needs to be done, but we believe the data and results obtained by this research will greatly help to set proper package design for boxes. Especially, safety factor would be practically helpful for researchers for future study and packaging users to save packaging costs.

Development of a Perception of Importance on Patient Safety Management Scale (PI-PSM)for Hospital Employee (병원 의료종사자의 환자안전관리 중요성 인식 측정도구 개발)

  • Park, Mi Jeong;Kim, In Sook;Ham, Young Lim
    • The Journal of the Korea Contents Association
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    • v.13 no.5
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    • pp.332-341
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    • 2013
  • The purpose of this study was to develop a perception of importance on patient safety management scale (PI-PSM) for Hospital Employee. The PI-PSM was developed and vallidated as follows: item generation, vertification of content validity, pilot study, and test of validity and reliability. In order to verify preliminary instrument, data was collected from 280 hospital employees. Data were analyzed by Varimax factor analysis and Cronbach's ${\alpha}$. There were 21 items in final instrument categorized into 4 factors as 'concern about patient safety management (7 items)', 'confidence about patient safety management (5 items)', 'will for patient safety management (5 items)', and 'recognition about patient safety management (4 items)'. The total varience explanined was 60.4%. The internal consistency, Cronbach's ${\alpha}$. was .86, and reliability of the sucscales ranged from .69 to .87. The results of this study may useful to assess the perception of importance on patient safety management.

A Study on the Correlation between the Building Perimeter and Safety Management Cost (건물의 외주길이와 안전관리비의 상관관계 분석에 관한 연구)

  • Han, Bum-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.4
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    • pp.359-370
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    • 2022
  • Despite continuous efforts to reduce on-site safety accidents, the construction industry remains a high-risk sector with a high rate of fatal accidents. Design for Safety(DFS), which manages safety risk factors at the design stage, is being used as a method to lower the construction safety accident rate. However, due to limited knowledge, designers are unaware of the design-results risks during the different of the project lifecycle, including construction, operation, and maintenance. Effective DFS can be conducted if the designer understands the effect of the building shape on the safety accident rate and corresponding safety management cost(SMC). The cost of safety facilities such as fall prevention nets and safety fences will vary depending on the shape of the building. This study analyzes the outer perimeter length's impact on SMC. Following the data collection from 21 projects for this study, an analysis was conducted using the independent variables of the building perimeter(BP), building shape factor(BSF), and building area(BA), the dependent variable of SMC. The correlation R2 was found to be 0.876, 0.801 and 0.792 between the BP and SMC, BSF and SMC, BA and SMC, respectively, indicating that these factors were closely related.

Numerical estimation for safety factors of tunnels considering the failure of supports (지보재 파괴를 고려한 터널 안전율의 수치해석적 산정 연구)

  • You, Kwang-Ho;Park, Yeon-Jun;Hong, Keun-Young;Lee, Hyun-Koo;Kim, Jea-Kwon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.7 no.1
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    • pp.37-49
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    • 2005
  • In a tunnel, failure of its supports can cause failure of the tunnel. Therefore it is important to estimate safety factor of the tunnel which the failure of its supports is taken into account. In previous studies, supports of tunnels were usually modelled as beam elements. The failure of the supports was decided by comparing the allowable stress and the calculated bending stresses inside the beam elements in estimating safety factor of the tunnel considering the failure of its supports. In this study, it is suggested how to model the supports properly. To this end, supports of a tunnel were modelled by both beam (elastic) elements and continuum (elasto-plastic) elements in two dimensional numerical analyses. Meanwhile, it was analyzed how rock mass class, coefficient of lateral pressure, shotcrete thickness, the existence of rock bolt, and excavation method had an effect on the safety factor of a tunnel.

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Study on Flow Characteristics and Discharge Coefficient of Safety Valve for LNG/LNG-FPSO Ships (LNG / LNG-FPSO 선박용 안전밸브의 유동특성 및 유출계수에 관한 연구)

  • Kim, Sung-Jin;Jung, Sung-Yuen;Kim, Dang-Ju;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.5
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    • pp.487-494
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    • 2011
  • The safety valve used in LNG/LNG-FPSO ships plays an important role in maintaining a fixed level of pressure by emitting LNG gas out of the pipes in the LNG piping system. The discharge coefficient is regarded as the most important factor in the valve performance. To satisfy the ship's classification, the discharge coefficient of the safety valve must usually be over 0.8. Despite the importance of understanding the flow phenomena inside the safety valve, the valve design is usually based on experience and experiments. We carried out a computational fluid dynamics (CFD) investigation using the ANSYS-CFX software. We observed the flow phenomena inside the valve and measured the discharge coefficients according to changes in the valve lift, which is the distance between the exit of the nozzle and the lower part of the disc plate. We verified our CFD results for the discharge coefficients using available experimental data.

Calculation of Cronbach's Alpha Coefficient, Generalizability Index (GI), and Dependability Index (DI) in the Model Types of Survey Design (서베이 설계 모형별 Cronbach's Alpha 계수와 GI, DI 산출방안)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2011.04a
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    • pp.701-705
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    • 2011
  • The paper reviews Cronbaha's coefficient to measure a single source of error. On the contrary to classical measurement theory, the generalizability study can be used in the social survey design to calculate Generalizability Index (GI) and Dependability Index (DI) for measuring multiple sources of errors of behavior evaluation. The study proposes application guidelines to implement R:($A{\times}B$) mixed models that are composed of random factor and fixed factor.

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Analysis of Quality Change Based on Storage Conditions to Set the Use-by date of Bakery Breads (베이커리 식빵의 소비기한 설정을 위한 보관 방법에 따른 품질 변화 연구)

  • Sun Hye Hwang;Ji Yeon Choi;Min Joo Kim;Yong Sun Cho
    • Journal of Food Hygiene and Safety
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    • v.38 no.4
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    • pp.236-245
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    • 2023
  • In this study, the quality safety limit period of seven types of bakery bread was analyzed, and their use-by date was calculated. For evaluating product quality, storage conditions were set as 5, 15, 25, and 35℃ for 50 days, and moisture, microorganisms, sensory characteristics, and dominant bacteria were examined. The quality and safety standards followed the Korea Food Code and Korean industrial standards (KS). The results showed that all products stored at 5℃ satisfied the standard for bacterial count for day 50, but the sensory quality was below the standard level. Samples stored at 15℃ showed high variability from 3-39 days. At 25℃, a quality safety limit period of 2-20 days was set, and one sample was found to have the same shelf life. Bread stored at 35 ℃ had the shortest quality safety limit period. Considering a safety factor of 0.87, a use-by date period of 1.7-13.1 days was calculated. Therefore, setting the use-by date according to the product type is necessary, even for the same product category. Among the bread products sold in bakeries, those managed as room temperature products (1-35℃) can be distributed and stored in a temperature range of up to 35℃. Overall, this study demonstrates the importance of setting a quality retention period based on the product characteristics and carefully considering the safety factor.

The Relationship between the Load Carrying Capacity and Transformed Impact Factor of Highway Bridge (교량의 공용내하력과 환산충격계수 관계 연구)

  • Chai, Won-Kyu;Lee, Myeong-Gu
    • Journal of the Korean Society of Safety
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    • v.27 no.6
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    • pp.138-143
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    • 2012
  • In this thesis, the relationship between the load carrying capacity and the transformed impact factor of the highway bridges were studied. The bridges are classified according to superstructures type. The result of the comparison between the load carrying capacity and the transformed impact factor, if the load capacity ratio of 0.57, the transformed impact factor was less in order of RC T-beam bridge, RC slab bridge, PC beam bridge, I-beam bridge. By the regression analysis on these results, the empirical formulae to predict the the load carrying capacity of bridge were suggested.

Reliability of Machine Elements Based on Static and Dynamic Factor of Allowable Safety under Fluctuating Load (변동하중을 받는 기계요소의 정 .동적 허용안전계수를 고려한 신뢰성)

  • 양성모;김강희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.475-480
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    • 1997
  • It is common to assum identical allowable safety factors in static strength, defined by mean stress and in fatigue, defined by stress amplitude. Under the load with asymmetrical cycles the safety factor is not the same. In this paper, with the consideration of unequal allowable safety factors a general method for estimating fatigue reliability of a machine element under a combined state of stress is derived based on the theory proposed by Prof. Kececioglu and normal distribution. The calculation of fatigue reliability for limited life is discussed with example.

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