• Title/Summary/Keyword: Safety State

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The Effectiveness of a Participatory Road Traffic Safety Education Program for the Elementary School Students (참여 중심 어린이 교통안전교육 프로그램 효과 평가)

  • Shon, Ju-Hyun;Lee, Myung-Sun
    • Korean Journal of Health Education and Promotion
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    • v.27 no.1
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    • pp.49-60
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    • 2010
  • Objectives: The purpose was to evaluate the effectiveness of participatory road safety education program for the lower grade in elementary schools. This program was developed based on the Activated Health Education model. Methods: Study design was compromise experimental group pre-post design. 456 students in 8 schools were nonrandomly assigned to study group(n=224) or control(n=232). The students finished self-administered questionnaire before and after education. Collected data was analyzed by using the SPSS. Results: 1. The common relevant factors in road safety knowledge and attitude were 'residential state' and 'experience of traffic accident'. 2. The knowledge showed that the case and control scored at 6.48 and 6.41 points before. After this intervention, the case and control scored at 8.38 and 6.51. The difference of the case was significant(p<0.001). 3. The attitude showed that the case and control scored at 19.67 and 19.63 before. After this, the case and control scored at 19.86 and 19.63. The difference of the case was significant(p<0.05). Conclusion: In order to implement the road safety education, children's socio-demographic characteristics were considered. Because this education was effective in both improving knowledge and attitude and bringing interest, various participatory program will be applied in road safety education for children.

Safety Seats Research in Toddler and Preschooler Parents (유아와 학령전기 아동 부모의 유아용 차량 내 보호 장구 이용 실태)

  • Lee, Ja-Hyung;Lee, Yong-Hwa
    • Korean Parent-Child Health Journal
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    • v.10 no.2
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    • pp.110-122
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    • 2007
  • Purpose: The purpose of this study was to research the actual state of the toddler and preschooler safety seats built into the car. Method: The design was a descriptive study by questionnaire. Data were collected from August, 1, 2007 to September, 30, 2007. A total 232 toddler and preschooler parents in Seoul and Inchon. Data were analysed using SPSS WIN 12.0. Result: The study show that people who did not get a education are 86.2%. Using the child safety seats also show that 96.1% of respondents are holding in their arms, only 3.0% of respondents used them. 21.1% answered that they get on the vehicles with holding their children in their arms and 48.3% answered that they let their children alone on the seat, just 29.7% are using the child safety seats. Conclusion: To increase child safety seats configurations rate, available education is needed. For this, contents about child safety seats must be included for education leaving the hospital by nurses who work in nursery. For the consideration about child safety seats configuration rate, complement of the legal system and development of available protective equipment and economical support of the nation and the local community is needed.

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A Study on Reliability Estimation of Sequential-ordered Multiple Failure Modes in Nuclear System (원자력시스템에서 순차적 다중실패상태의 신뢰도 평가 방법에 관한 고찰)

  • Han, Seok-Jung
    • Journal of the Korean Society of Safety
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    • v.26 no.4
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    • pp.7-13
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    • 2011
  • A study on reliability estimation of sequential-ordered multiple failure modes, which are sequentially ordered between failure modes in a considering system, was performed. Especially, an approach to estimate the probabilities of failure modes has been proposed under an assumption that failure modes are mutually exclusive and sequentially ordered by only a critical variable. A feasibility of the proposed approach were studied by a practical example, which is a reliability estimation of passive safety systems for a probabilistic safety assessment(PSA) of a very high temperature reactor(VHTR) that is under development as a future nuclear system with enhanced safety features. It is difficult to define a robust failure state of this nuclear system because of its enhanced radiation release characteristics, so the new approach is a useful concept to estimate not only its safety but also a PSA. A feasibility study applied two failure modes(e.g., small and large release of radioactive materials) with considering the integrated behavior of this nuclear system. It is expected that the multiple release states for a practical estimation can be easily extended to the aforementioned example. It was found out that the proposed approach was a useful technique to cover the unfavorable features of this nuclear system as to performing a VHTR PSA.

Structural safety reliability of concrete buildings of HTR-PM in accidental double-ended break of hot gas ducts

  • Guo, Quanquan;Wang, Shaoxu;Chen, Shenggang;Sun, Yunlong
    • Nuclear Engineering and Technology
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    • v.52 no.5
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    • pp.1051-1065
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    • 2020
  • Safety analysis of nuclear power plant (NPP) especially in accident conditions is a basic and necessary issue for applications and commercialization of reactors. Many previous researches and development works have been conducted. However, most achievements focused on the safety reliability of primary pressure system vessels. Few literatures studied the structural safety of huge concrete structures surrounding primary pressure system, especially for the fourth generation NPP which allows existing of through cracks. In this paper, structural safety reliability of concrete structures of HTR-PM in accidental double-ended break of hot gas ducts was studied by Exceedance Probability Method. It was calculated by Monte Carlo approaches applying numerical simulations by Abaqus. Damage parameters were proposed and used to define the property of concrete, which can perfectly describe the crack state of concrete structures. Calculation results indicated that functional failure determined by deterministic safety analysis was decided by the crack resistance capability of containment buildings, whereas the bearing capacity of concrete structures possess a high safety margin. The failure probability of concrete structures during an accident of double-ended break of hot gas ducts will be 31.18%. Adding the consideration the contingency occurrence probability of the accident, probability of functional failure is sufficiently low.

A Study on the Characteristics of Heat Distribution of Welded Joint on the Steel Structure with Thick Plate (厚板 鋼構造物 熔接이음부의 熱分布 特性에 關한 硏究)

  • 방한서;김종명
    • Journal of Welding and Joining
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    • v.13 no.1
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    • pp.138-144
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    • 1995
  • Recently, as the industrial structure tends to become large, the thickness of structural plate becomes thicker. Therefore, the thicker the plate of welded structure is, the larger the shape of welded joint. The effect of large heat input makes large heat affected zone(HAZ). These bring to complict welding residual stress and to weaken material, which may cause extremely harm to the safety of structures. Nevertheless, welding is design is regulated by the KS, JIS or standard in the resister of shipping such as KR, ABS or LR. However, these rules are based on rather experimental than theoretical. In this study, the computer program of heat conduction, considering un-steady state and quasi-steady state, is developed for optimizing(minimizing) a shape of welded joint. The characteristics of heat on the welded joints with various shapes are clarified by the results of the analyses.

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A coupled wind-vehicle-bridge system and its applications: a review

  • Cai, C.S.;Hu, Jiexuan;Chen, Suren;Han, Yan;Zhang, Wei;Kong, Xuan
    • Wind and Structures
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    • v.20 no.2
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    • pp.117-142
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    • 2015
  • The performance of bridges under strong wind and traffic is of great importance to set the traveling speed limit or to make operational decisions for severe weather, such as controlling traffic or even closing the bridge. Meanwhile, the vehicle's safety is highly concerned when it is running on bridges or highways under strong wind. During the past two decades, researchers have made significant contributions to the simulation of the wind-vehicle-bridge system and their interactive effects. This paper aims to provide a comprehensive review of the overall performance of the bridge and traffic system under strong wind, including bridge structures and vehicles, and the associated mitigation efforts.

CURRENT CONTROL FOR PWM AC-DC CONVERTER USING SINUSOIDAL TRACKING CONTROLLER

  • Woo, Jung-In;Heo, Tae-Won;Lee, Hyun-Woo;Kim, Choon-Sam;Jung, Yung-Il
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.928-933
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    • 1998
  • This paper presents a novel current control system to eliminate the steady state control error and to improve the transient characteristics for PWM AC-DC converter. A general mathematical model of the converter that is represented as a state-space model is first established. The state-space model is used for the simulation of PWM switching converter with the proposed current control system. The proposed sinusoidal tracking control system that does not require coordinate transformations using principle of the integral controller is described. It is proved that the steady state deviation reduces to zero through a transfer function of source current control system. Finally, it is seen that simulations agree with the experimental results in source current and reference of controlled ac current loop.

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Introduction of the Capacity Design Methodology in the Building Standard Law of Japan (개정된 일본 내진설계기준의 한계내력계산법의 소개)

  • 전대한;노필성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.861-866
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    • 2002
  • This manuscript introduces the Capacity Design Methodology in the Building Standard Law of Japan revised at 2000, June. The Building Standard Law of Japan was revised into the performance-based design format following the trend of international. The structural performance was evaluated for two limiting states; soundness limit state and safety limit state. The design seismic forces were determined on taking into consideration (a)the properties of the planned building, (b)amplification by local surfaces geology, and (c)soil-structure interaction.

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Structural Evaluation of Prototype Bridge using Concrete Weight Blocks (콘크리트 블록을 이용한 실교량의 구조성능평가기법)

  • 심종성;오홍섭;유재명
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.429-432
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    • 2000
  • Test methods by hydraulic oil or vehicular live load have been used for structural evaluation of prototype bridge. However it has been reported that the use of hydraulic jack has some disadvantages for the view of safety and economy, and the complete structural evaluation through each loading state can not be accomplished blocks is presented to overcome those demerits. To verify the application and safely of the use of concrete weight blocks during each loading state, it is applied to prototype deteriorated bridge. As a result, it could be evaluated the structural behavior completely using the concrete weight blocks

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Reliability Assessments and Design Load Factors for Reinforced Concrete Containment Structures of Nuclear Power Plant

  • Han, Bong-Koo
    • Nuclear Engineering and Technology
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    • v.29 no.6
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    • pp.444-450
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    • 1997
  • The current ASME code for reinforced concrete containment structures are not based on probability concepts. The stochastic nature of natural hazard or accidental loads and the variations of material properties require a probabilistic approach for a rational assessment of structural safety and performance. The paper develops design load factors for the serviceability limit state of reinforced concrete containment structures. The target limit state probability is determined and the load factors are calculated by the numerical analysis. Design load factors are proposed and carried out the reliability assessments.

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