• Earthquakes and Structures
• /
• 제14권2호
• /
• pp.143-153
• /
• 2018

Correlation among different factors must be considered for selection of influencing factors in safety monitoring of high dam including positive correlation of variables. Therefore, a new factor selection method was constructed based on Copula entropy and mutual information theory, which was deduced and optimized. Considering the small sample size in high dam monitoring and distribution of daily monitoring samples, a computing method that avoids causality of structure as much as possible is needed. The two-dimensional normal information diffusion and fuzzy reasoning of pattern recognition field are based on the weight theory, which avoids complicated causes of the studying structure. Hence, it is used to dam safety monitoring field and simplified, which increases sample information appropriately. Next, a complete system integrating high dam monitoring and uncertainty prediction method was established by combining Copula entropy theory and information diffusion theory. Finally, the proposed method was applied in seepage monitoring of Nuozhadu clay core-wall rockfill dam. Its selection of influencing factors and processing of sample data were compared with different models. Results demonstrated that the proposed method increases the prediction accuracy to some extent.

• 한국방재안전학회논문집
• /
• 제5권1호
• /
• pp.29-36
• /
• 2012

본 연구에서는 개발도상국에서 선진국으로 발전하는 과정에서 겪는 시민안전 향상을 위한 새로운 이론과 알고리즘을 제시하고 있으며, 얻어지고 적용된 결론을 분석하고, 시민의 생명과 재산을 재난으로부터 보호하기 위한 이론과 적용된 사례를 보여주고 있다. 인간보호를 위한 안전모니터링 이론은 사고로 인한 사망자를 분석하여 감소시킬 수 있는 여섯가지 이론을 제시하고 있으며, 이는 재해예방활동의 우선순위, 의사결정, 사건사망자수의 지속적인 최소화, 환경안보, 개인안보, 공동체 안보 등이다. 이 연구는 일곱 단계로 구성된 안전모니터링 모델을 적용한 방재안전관리 프로그램을 교육하고 훈련하는데 적용되었고, 5년간의 개인활동과 그룹활동 사례연구를 통한 지속적으로 향상된 효과를 제시하였다.

• Structural Monitoring and Maintenance
• /
• 제5권1호
• /
• pp.79-92
• /
• 2018

The evaluation theory of reliability, availability, maintainability and safety (RAMS) as a mature theory of state evaluation in the railway engineering, can be well used to the evaluation, management, and maintenance of complicated structure like the long-span bridge structures on the high-speed railway. Taking a typical steel-truss arch bridge on the Beijing-Shanghai high-speed railway, the Nanjing Dashengguan Yangtze River Bridge, this paper developed a new method of state evaluation for the existing steel-truss arch high-speed railway bridge. The evaluation framework of serving state for the bridge structure is presented based on the RAMS theory. According to the failure-risk, safety/availability, maintenance of bridge members, the state evaluation method of each monitoring item is presented. The weights of the performance items and the monitoring items in all evaluation levels are obtained using the analytic hierarchy process. Finally, the comprehensive serving state of bridge structure is hierarchical evaluated.

• 한국가스학회지
• /
• 제21권2호
• /
• pp.58-63
• /
• 2017

복잡한 플랜트 환경에서의 안전관리는 인적 요인에 의해 좌우되고 있는 상황이다. 이로 인해 인적 오류에 의한 상황 파악의 실패는 심각한 사고의 원인이 되고 있다. 이를 위해 본 논문에서는 청각 정보에 의해 상황을 인지할 수 있도록 함으로써 복잡한 환경에서의 안전점검의 새로운 수단을 제시하고자 하며, 인간에 의한 경험적 정보를 수반한 상황 인지율을 달성하기 위해 지능이론의 기법 중에서 퍼지이론을 적용하여 음향 정보를 이용한 안전진단 시스템을 제안하고자 한다. 고압가스 충전시설은 매우 단순한 형태이며, 향후 더욱 복잡한 플랜트 시설에 적용이 가능할 것으로 전망한다.

• 한국방재안전학회논문집
• /
• 제7권1호
• /
• pp.1-8
• /
• 2014

서울거리모니터 실태조사에 따르면, 2013년 서울시 균형성과지표 5,000건 대비 18,490건(12월말 기준)을 신고하여 17,903건을 조치하였다. 2012년 1,151건의 신고에 비해 대폭 증가하였지만 지역 연령 직업 성별 편차가 심하고 전체인력의 3.9%에 불과한 우수 활동자 25명이 13,880건을 신고하여 총 신고실적의 75.1%에 달하는 높은 의존도를 나타냈다. 거리모니터활동은 허버트 윌리엄 하인리히(H.W Heinrich)의 재해발생 "도미노이론"과 "1:29:300의 법칙"에 의거하면 불안전한 상태를 제거함으로서, 사망자 54명, 중경상자 1,573명과 잠재적 부상자 16,275명을 감소시켜 총 17,903명에 달하는 서울시민의 생명을 존중하고 보호하였다. 본 연구에서는 서울거리모니터와 강동구거리모니터 비교분석을 통한 문제점을 도출하여 모니터링활동의 효율적인 개선방안을 제시하였다.

• Smart Structures and Systems
• /
• 제14권3호
• /
• pp.267-284
• /
• 2014

This paper aims to present the analytical solutions of 2-2 cement based piezoelectric transducers in series electrically based on the theory of piezo-elastic dynamics. The solutions of two different kinds of 2-2 cement based piezoelectric transducers under external harmonic load are obtained by using the displacement method. The effects of electrical connection of piezoelectric layers, loading frequency, thickness and distance of piezoelectric layers on the characteristics of the transducers are discussed. Comparisons with other related experimental investigations are also given, and good agreement is found. The proposed 2-2 cement based piezoelectric transducers have a great potential application in monitoring structural health in civil engineering and capturing mechanical energy or monitoring train-running safety in railway system and traffic safety in road system.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 1999년도 추계학술대회
• /
• pp.217-236
• /
• 1999

Engineering process control (EPC) is one of the techniques very widely used in process. EPC is based on control theory which aims at keeping the process on target. Statistical process control (SPC), also known as statistical process monitoring. The main purpose of SPC is to look for assignable causes (variability) in the process data. The combined SPC/EPC scheme is gaining recognition in the process industries where the process frequently experiences a drifting mean. This paper aims to study the difference between SPC and EPC in simple terms and presents a case study that demonstrates successful integration of SPC and EPC for a product in drifting industry. Statistical process control (SPC) monitoring of the special causes of a process, along with engineering feedback control such as proportional-integral-derivative (PID) control, is a major tool for on-line quality improvement.

• Safety and Health at Work
• /
• 제12권3호
• /
• pp.339-345
• /
• 2021

Background: Some researchers state that they are not yet able to provide a deep understanding of the underlying causes of unsafe behaviors (UBs). Therefore, the present study was conducted to investigate the attitudes and experiences of Iranian workers of UBs. Methods: This present study was conducted in 35 industries using a semistructured interview based on grounded theory. Forty participants were interviewed, including 13 industrial safety and health experts and 27 workers and supervisors. The analysis of the present study consisted of a three-step coding process including open, axial, and selective coding. Results: The results showed that the factors affecting UBs could be classified into three categories: organizational, individual, and socioeconomic factors. Organizational factors were divided into 6 parts: procedure and environmental conditions, communications, monitoring, organizational safety culture, resource allocation, and human resources. Socioeconomic factors had three subcategories: community safety culture, type of organizational ownership, and economic problems. Finally, the individual factors were classified into two categories of personality traits and individual competence. Conclusion: The results showed that organizational factors were the most categorized, and it is estimated that this factor has a more important role in the UBs. Of course, to better understand the close relationship between these factors and find the weight and importance of each factor, it needs to measure it with multicriteria decision systems.

• 한국지반공학회논문집
• /
• 제31권4호
• /
• pp.19-29
• /
• 2015

최근 국내에서는 굴착현장의 안전성에 대한 중요성 때문에 현장계측과 수치해석을 활용한 시공 관리방안에 대한 관심이 점점 더 높아지고 있다. 따라서 본 연구는 이를 위한 대안으로서 국내 다양한 굴착현장의 계측(경사계)자료들을 활용하여 미지점에 대한 변위값 추정과 기지점에서 향후 발생될 것으로 예상되는 변위값 예측을 위해 플랙탈(Fractal) 이론의 적용성을 검토하였다. 계측자료는 일반현장과 붕괴사고가 발생된 현장의 자료를 분석하였는데, 분석 시에는 계측 주기에 따른 수평변위의 변화 양상에 대해서 Hurst 지수를 산정하여 예측값을 모사하는데 사용하였으며, 그 결과를 실측값과 비교 검토하였다. 그 결과, 일반현장의 계측결과의 Hurst, H=0.7~0.8의 범위로 나타났다. 이는 H > 1/2로서 양의 상관성을 나타내 자기 유사성(self-similarity)을 확인할 수 있었으며, Hurst 지수로 모의된 예측값들은 계측값들과 매우 높은 상관성을 나타내었다. 또한 붕과가 발생된 현장의 계측자료들에 대한 분석결과에서는 붕괴발생 수주일 전부터 Hurst 지수의 이상 변화가 나타나는 것을 확인할 수 있었다. 따라서 향후 추가적인 자료축적을 통하여 굴착현장 흙막이 벽체의 안전관리에 플랙탈 이론을 활용성을 확인할 수 있었다.

• Safety and Health at Work
• /
• 제9권2호
• /
• pp.140-143
• /
• 2018

Background: The Occupational Safety and Health Monitoring and Assessment Tool (OSH-MAT) is a practical instrument that is currently used in the German woodworking and metalworking industries to monitor safety conditions at workplaces. The 12-item scoring system has three subscales rating technical, organizational, and personnel-related conditions in a company. Each item has a rating value ranging from 1 to 9, with higher values indicating higher standard of safety conditions. Methods: The reliability of this instrument was evaluated in a cross-sectional survey among 128 companies and its validity among 30,514 companies. The inter-rater reliability of the instrument was examined independently and simultaneously by two well-trained safety engineers. Agreement between the double ratings was quantified by the intraclass correlation coefficient and absolute agreement of the rating values. The content validity of the OSH-MAT was evaluated by quantifying the association between OSH-MAT values and 5-year average injury rates by Poisson regression analysis adjusted for the size of the companies and industrial sectors. The construct validity of OSH-MAT was examined by principle component factor analysis. Results: Our analysis indicated good to very good inter-rater reliability (intraclass correlation coefficient = 0.64-0.74) of OSH-MAT values with an absolute agreement of between 72% and 81%. Factor analysis identified three component subscales that met exactly the structure theory of this instrument. The Poisson regression analysis demonstrated a statistically significant exposure-response relationship between OSH-MAT values and the 5-year average injury rates. Conclusion: These analyses indicate that OSH-MAT is a valid and reliable instrument that can be used effectively to monitor safety conditions at workplaces.