• Title/Summary/Keyword: Partial safety factors

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Perceptional Characteristics of Effective Safety Signs Corresponding to International Criteria (국제 기준에 부합하는 효과적 안전표지의 지각 특성)

  • Lim, Hyeon-Kyo;Park, Young-Won;Jung, Gwang-Tae
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.111-118
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    • 2008
  • In usual safety signs are final means to transmit hazard information so that the importance of them cannot be emphasized too much. Nevertheless, in Korea, few people are interested in functions of safety signs so that evaluation of safety signs are seldom committed. This research was conducted to evaluate and compare perceptional characteristics of safety signs, especially "Fall" signs, by Semantic Differential Method and Multi-dimensional Scaling Method, with undergraduate students as well as industrial workers. According to research results on several signs evaluated high through suggested procedure, action inducibility was different for students majoring in different sciences, but it had common elements in the sense of 'openness' or 'arrangements'. Besides, perceptional images on safety signs were mainly recognized with bases of 'arrangement' for student group and 'simplicity' for industrial workers, respectively, and their maps corresponded well with each other by partial rotating so that students and workers seemed to recognize safety signs with similar factors though their name might be different. However, since perceptional characteristics including image map, comprehensibility, and action inducibility were similar for student group whereas those were not for worker group, it was concluded that the test for action inducibility would be absolutely necessary for safety signs for workers' group.

Sensitivity Analysis by Parametric Study of Load Factor for a Concrete Box Girder Railway Bridge Using Limit State Design

  • Yeo, Inho;Sim, Hyung-Bo;Kim, Daehwan;Kim, Yonghan
    • International Journal of Railway
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    • v.8 no.1
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    • pp.5-9
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    • 2015
  • Reliability based limit state design method is replacing traditional deterministic designs such as allowable stress design and/or ultimate strength design methods in world trends. European design code(Eurocode) has adopted limit state design, and Korea road bridge design standard has also recently been transferred to limit state design method. In this trend, Korea railroad design standard is also preparing for adopting the same design concept. While safety factors are determined empirically in traditional design, load combinations as well as load factors are determined by solving limit state equations. General partial safety factors are evaluated by using AFORM(Advanced First Order Reliability Method) in the reliability based limit state design method. In this study sensitivity analysis is carried out for a dead load factor and a live load factor. Relative precisions of the dead load and the live load factors are discussed prior to the AFORM analysis. Furthermore the sectional forces of design and the material quantities required by two different design methods are compared for a PSC box girder railway bridge.

Identifying Regional Characteristics Faxtors Affecting the Number of Tuberculosis Death - The Comparative Analysis between Urban and Rural areas - (결핵 사망자수에 영향을 미치는 지역특성 요인 규명 - 도시 및 비도시지역 비교분석 -)

  • Yoon, Sanghoon;Park, Keunoh
    • Journal of the Society of Disaster Information
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    • v.16 no.3
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    • pp.513-525
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    • 2020
  • Purpose: The purpose of this study is to analyze the characteristics of local factors affecting number of tuberculosis death by urban and rural areas. Method: The Partial Least Square(PLS) Regression analysis was used to solve the problem of multicollinearity and number of samples. Result: As a result of analysis, The number of tuberculosis deaths in urban and rural areas is about three times as large. As a result of analysis about Regional Characteristics Factor, In general, children, elderly people, and economically vulnerable populations are more likely to be exposed to tuberculosis. In differential results, it shows that environmental factors such as ultrafine dust and sulfur dioxide have a significant impact on the number of tuberculosis deaths in urban areas and social factors such as depression experience rate in rural areas. Conclusion: The Tuberculosis prevention and management policies that reflect the characteristics of urban and rural areas are needed in the future.

Reliability-based design of prestressed concrete girders in integral Abutment Bridges for thermal effects

  • Kim, WooSeok;Laman, Jeffrey A.;Park, Jong Yil
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.305-322
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    • 2014
  • Reliability-based design limit states and associated partial load factors provide a consistent level of design safety across bridge types and members. However, limit states in the current AASHTO LRFD have not been developed explicitly for the situation encountered by integral abutment bridges (IABs) that have unique boundary conditions and loads with inherent uncertainties. Therefore, new reliability-based limit states for IABs considering the variability of the abutment support conditions and thermal loading must be developed to achieve IAB designs that achieve the same safety level as other bridge designs. Prestressed concrete girder bridges are considered in this study and are subjected to concrete time-dependent effects (creep and shrinkage), backfill pressure, temperature fluctuation and temperature gradient. Based on the previously established database for bridge loads and resistances, reliability analyses are performed. The IAB limit states proposed herein are intended to supplement current AASHTO LRFD limit states as specified in AASHTO LRFD Table 3.4.1-1.

Development of Mobile Equipment for Local Risk Factors Detecting of Road Slope (도로사면의 국부적 위험요인 검지를 위한 이동형 장비 개발)

  • Kim, Yong-Soo;Jung, Soo-Jung;Ahn, Sang-Ro
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.938-945
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    • 2008
  • Rockfall and landslide bring about a great social loss with loss of property such as obstruction of traffic and damage of the crops as well as casualty. The purpose of this study is to develop a mobile equipment for local risk factors detecting of road slope. The mobile equipment is designed to receive the sensing data from the measurement sensors, which are installed to detect the dangerous signs from the slopes, as loaded on a vehicle which is moving around to the places where the sensors are installed. In general, more than one mandatory data logger, which is very expensive, must be installed at each slope for the automatic measuring system, but in case of this developmental system, the inexpensive routine measurement can be performed regardless of the number of slopes due to the single unit of information gathering vehicle. This study is going to develop technologies that are expected to be applied to not only slope but also tunnel and bridges which might have the partial risk and need measuring.

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A Study on Engineering Characteristics of Geogrids and the Applicability in fields (지오그리드의 공학적 특성 및 설계인자 적용성 평가에 관한 연구)

  • 신은철;김두환;신동훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.105-112
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    • 1999
  • In recent the superior economic benefits and the convenience of installation increased the use of geosynthetics, especially geogrids with the effects of high tensile strength. In this study, various tests were conducted to determine the physical and chemical properties of geogrids which contains durability under various critical conditions, creep behavior and the stability for installation damage in fields. With analysis of test results, the partial and total safety factors were determined and presented the long term design strength of flexible geogrids.

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A Study on the Improvement of Safety Perception and Safety Action of Cabin Crews: Focusing on the Airlines Safety Climate (객실승무원의 안전지각과 안전행동 향상을 위한 연구: 항공사 안전 분위기를 중심으로)

  • Park, Hee Jung
    • Journal of the Korean Society of Safety
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    • v.34 no.6
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    • pp.76-87
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    • 2019
  • This study was conducted to check the cabin crew's safety perception in relation to the airline's safety climate and cabin crew's safety action and to verify that the safety perception's mediation effects. The results of the study confirmed that all three factors of the safety climate have a significant impact on safety perception, and among them, safety practice is the most significant. Accordingly, Airlines need to establish a community that enables real-time information exchange for air accidents so that the cabin crew can present real-time examples of safety-related accidents. In addition, it will be necessary to work with external safety agencies to form an active attitude for the establishment of safety procedures in order to prevent recurrence of safety problems while considering the causes of such incidents internally in the event of an airline safety accident. In addition, it was confirmed that safety training was the most significant factor to safety action, among which all three elements of the safety climate had a significant effect on safety action. Therefore, airlines need to expand practical training on aircraft to full-scale safety training to build an immediate resolution for cabin crews in the event of an air accident. In addition, safety training should be established to encourage collaboration among aviation safety-related personnel to participate in safety training together to address aviation safety from a diverse point of view. Safety perception was has a significant effect on safe action. Therefore, airlines should reinforce the airline's safety management system by checking the status of the cabin crew's safety perception extending the level of punishment to the scope of retirement or disqualification to establish a firm awareness of safety. Finally, the safety perception has demonstrated partial mediation effects in relation to the safety climate and safety action. Therefore, the airline needs to improve the duties of the cabin crew that interferes with cabin safety duties. In addition, airlines should utilize advertisements emphasizing that safety is first.

Reliability based calibration of the capacity design rule of reinforced concrete beam-column joints

  • Thomos, George C.;Trezos, Constantin G.
    • Computers and Concrete
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    • v.8 no.6
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    • pp.631-645
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    • 2011
  • The capacity design rule for beam-column joints, as adopted by the EC8, forces the formation of the plastic hinges to be developed in beams rather than in columns. This is achieved by deriving the design moments of the columns of a joint from equilibrium conditions, assuming that plastic hinges with their possible overstrengths have been developed in the adjacent beams of the joint. In this equilibrium the parameters (dimensions, material properties, axial forces etc) are, in general, random variables. Hence, the capacity design is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the capacity design rule of joints is being calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design rule for beam-column joints is proposed, in order to achieve uniformity of the safety level.

The Impact of Safety Communication at Workplaces Employing Foreigners on Industrial Accident Awareness: The Relationship between Safety Communication and Industrial Accident Awareness Mediated by Foreign Workers' Skill Level (외국인 고용 사업장의 안전 소통이 산재인식에 미치는 영향: 외국인 근로자의 숙련도가 매개하는 안전소통과 산재인식의 관계)

  • Kwang Jae Chung;Changkwon Park;Gilsang Jang
    • Journal of the Korea Safety Management & Science
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    • v.25 no.4
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    • pp.35-43
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    • 2023
  • In recent years, there has been a growing trend of occupational accidents involving foreign workers. As the number of foreign workers continues to increase, the risk of occupational accidents is also on the rise. Therefore, it is crucial to take proactive measures to prevent occupational accidents among foreign workers. To establish a common safety culture among foreign workers with varied backgrounds and educational experiences, and which is harmonized with Korean workplace. Safety communication, which includes culture respect and participation in the workplace, plays a significant role in shaping and developing the safety culture of foreign workers. Therefore, this study aims to assess the level of safety culture in workplace employing foreign workers by analyzing the reliability and validity of factors such as 'occupational accident awareness' and 'safety communication,' which constitute the safety culture at these workplace. Additionally, the mediating effect of 'work proficiency' on the relationship between 'safety communication' and the level of improvement in 'occupational accident awareness' using the validation method proposed by Baron & Kenny(1986). As a result of statistical analysis, The influence of'safety communication'on'occupational accident awareness'is 𝛽=0.339, and it has been found that this influence decreases to 𝛽=0.113 when'work proficiency'is introduced, indicating partial mediation.

Reliability Analysis on the Decision Method of Lateral Flow of Foundation Piles for Abutment (교대 기초말뚝의 측방유동 판정식에 관한 신뢰성 해석)

  • Ahn, Jong-Pil;Kim, Gyu-Deok;Kim, Il-Goo;Choi, Jin-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1090-1097
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    • 2008
  • This study conducted the decision method of lateral flow in abutment structures founded on the soft soils and the reliability analysis on the foundation pile for abutment. On the basis of the results, this study proposed the reliability design model. Reliability analysis was conducted by applying second moment method, point estimation method, and expected total cost minimization to lateral movement index, lateral movement decision index, modified lateral movement decision index, and circular failure safety factor for the decision criteria of lateral flow. The reliability index by analysis method had a similar tendency each other. Point estimation method was found as a practical method in the aspect of convenience because it could conduct the analysis only by mean and standard deviation as well as the partial derivative on random variables was not necessary. Optimum reliability index and optimum safety according to increasing in failure factors and load ratio were analyzed and loads and resistance factors of the design criteria of optimum reliability were estimated. It presented rational design model which can consider construction level and stability and economical efficiency overall.

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