구조물의 최적안전지수와 생애주기비용의 상관관계에 관한 연구

방명석 ( Myung Seok Bang ) 한국안전학회(구 한국산업안전학회) 2014 한국안전학회지 Vol.29 No.6

본 연구는 구조물의 최적안전수준과 수명기간동안 투자되는 총비용과의 상관관계를 연구하였다. 설계, 건설 및 공용 중 투자되는 총비용을 최소화하면서 최적의 안전수준을 결정하기 위하여 신뢰성해석을 수행하였다. 신뢰성해석에는 설계인자들의 불확실성과 설계 및 공사, 유지관리를 수행하는 인간의 오류 등 인적 불확실성을 확률변수로 고려하였다. 이러한 확률해석을 통한 안전지수와 생애주기비용의 상관관계를 연구하고, 생애주기비용의 분산도에 따른 안전지수의 민감도해석을 통하여 최적의 안전수준을 결정하였다. 해석결과는 이러한 평가방법이 교통시설물에 투자되는 비용을 최소화하면서 최적의 안전수준을 결정할 수 있는 정확하고 유용한 방법임을 보여주었다. This study was intend to develop the optimal design method of suspension bridge by the reliability analysis based on minimization of life cycle cost(LCC). The reliability analysis was performed considering aleatory uncertainties included in the result of numerical analysis. The optimal design was estimated based on life-cycle cost analysis depending on the result of reliability analysis. As the effect of epistemic uncertainty, the safety index (beta), failure probability (pf) and minimum life cycle cost were random variables. The high-level distributions were generated, from which the critical percentile values were obtained for a conservative bridge design through sensitivity assessment.

산업안전관리의 개선방안에 관한 연구

조주현 한국산업안전학회 1986 한국안전학회지 Vol.1 No.1

생산위주의 개발도상국 진입으로 산업재해가 크게 증가하는 추세에 있음은 중대한 문제로 되고있다. 산업안전관리는 기술적으로 잘하면 최대 98%까지 예방가능한 분야이다. 안전사고의 원인을 이적 근로자적 측면에서 경영자적 측면에서 분석하고 이를 조화 또는 통제하는 요인으로 관리적, 행정적 요인을 분석하였다. 개선방안은 산업의 고도화, 다양화에 따른 신기술부족, 안전지식 및 교육부족, 그리고 중소기업의 산업안전 보건시설 개선의 미홉등, 이들 직접 원인에 대한 통제 및 조화 수단으로서 법체제, 행정조직을 강화하고 산업안전관리를 민간주도로 추진해나갈 연구 및 예방기관의 육성이 되어야 한다.

차단기에 누적된 도전성 분진에 의한 아크 위험성

김두현 ( Doo Hyun Kim ),강양현 ( Yang Hyun Kang ),김은진 ( Eun Jin Kim ),황동규 ( Dong Gyu Hwang ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

In general, the causes of the electrical fire are overcurrent, short circuit, poor contact, etc. This study is aimed to recognize the risk of electric arc to prevent electrical fires due to the conductive dust accumulated on the circuit breaker. The experiment was carried out by the method that conductive metal dust collected from the field is being accumulated on the experimental electrodes with gap of 13 mm until the arc is generated. In case that arc was generated, the amount of conductive dust was measured and the thickness was calculated. This experiments was conducted by particle size. In order to distinguish particle size, mesh size(60~100, 100~150, 150~200, 200~250mesh) was classified using a sieve. As the results of experiment for each of the particle sizes, it was confirmed that there is differences in the generation of arc depending on the thickness of dust accumulated.

축소 모의된 22.9 kV-Y 배전선로의 유도 전압에 대한 신뢰성 검증

김점식 ( Jeom Sik Kim ),최충석 ( Chung Seog Choi ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

The purpose of this paper is to measure the induced voltage of the downscaled and simulated overhead ground wire of a 22.9kV-Y distribution line. This study performed a test of the downscaled and simulated distribution line according to whether it is grounded or not and the value of the ground resistance. In order to verify the reliability of the data measured by the test, the data was analyzed using the Minitab 17 program. It was found that the induced voltage of the downscaled and simulated distribution line is influenced by the value of the ground resistance. It was also found that the ground resistance obtained at a certain point is closely related to whether electric poles are grounded or not. The analysis results of the measured test data with a statistical method showed that the Anderson Darling (AD) was analyzed to be the smallest as 0.188 when the ground resistance of the electric poles had been maintained at 10Ω. In addition, the P value analyzed to be 0.894 which is in the proximity of the theoretical value of 1 and verified the reliability of the test data. It could be seen that the data measured by the downscaled simulation test forms a linear graph. It is thought that if a distribution line is installed in the same manner as the downscaled, simulated distribution line, the mean induced voltage will be reduced and reliability will be increased.

전원용 SPD의 건전성 평가 장치 개발

장석훈 ( Sughun Chang ),김영진 ( Youngjin Kim ),김성주 ( Sungju Kim ),김재형 ( Jaehyung Kim ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

This paper deals with development of integrity evaluation instrument for the power line surge protective device. A reliable power supply is an essential element in the developed information and communication society by highly advances in IT technology. However, the lightning incidence also increased with the recent extreme weather events. In Korea, in order to protect the electrical system from lightning surge, SPD(Surge Protective Device) has been used for these past 30 years. However, the method of diagnosing the safety of the SPD in the industry is insufficient. In this paper, SPD integrity evaluation system was composed of a variable DC power source unit, voltage-current sensor and the embedded controller. In order to measure V-I characteristics of MOV, 3 type samples were degraded by impulse current generator. After impulse tests, the varistor voltage of all samples and nonlinearity coefficient were decreased. It confirmed the utility of the developed equipment by this experimental test and the reliability of SPD is expected for surge accident prevention when applied to industrial plant.

표고버섯 원목재배 작업의 주요 위험요인과 안전대책

조성필 ( Sungpill Jo ),최경희 ( Kyeong Hee Choi ),공용구 ( Yong Ku Kong ),채혜선 ( Hye Seon Chae ),이인석 ( Inseok Lee ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.5

It is important to provide the farmers with practical and effective information of safety and health for individual crop to prevent or reduce occupational injuries in agricultural sector, since work characteristics and risk factors are not the same for all crops. In this study, risk assessment was carried out for cultivating shiitake mushrooms and then safety measures, which were based on the results of the risk assessment, were summarized and presented as the information of safety and health of shittake farmers. Guidelines for safety and health of the farmers of shiitake mushrooms, which were developed based on the risk assesment and safety measures, can be used by the farmers as self-educational tools or by the agricultural facilitators as an educational material for agricultural safety. It is expected that the guidelines can be useful in preventing occupational injuries of shiitake farmers.

철도차량 제동장치의 위험도 평가

이성권 ( Sung Kwun Lee ),김종운 ( Jong Un Kim ),구정서 ( Jeong Seo Koo ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.5

FMEA and FTA have been widely applied to the safety studies for railway systems respectively. But it would be more effective to use these two methods at a same time because these are complementary. This article suggests a FMEA-FTA combined analysis technique to evaluate the risk for railway systems. A FMEA-FTA combined risk evaluation model and process are proposed and a case study is dealt with for PBU(Pneumatic Breaking Unit), a major subsystem of a railway vehicle.

중수로 원자로건물 총누설감시계통 시험 중지에 따른 리스크 영향 평가

배연경 ( Yeon Kyoung Bae ),나장환 ( Jang Hwan Na ),방기인 ( Ki In Bahng ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.5

Wolsong Unit 2,3&4 has been performing a containment integrity test during power operation. This test could impact to the safe operation during test. If an accident occurs during pressure dropping phase, reactor trip can be delayed because of the increased pressure difference which causes a time delay to reach the trip set-point. On the contrary, if an accident occurs during pressure increasing phase, reactor trip could be accelerated because the pressure difference to the trip set-point decrease. Point Lepreau nuclear power plant, which installed GCLMS (Gross Containment Leakage Monitoring System) in 1990, has discontinued the test since 1992 due to these adverse effects. Therefore, we evaluated the risk to obviate the GCLMS test based on PWR’s ILRT (Integrated Leak Rate Test) extension methodologies. The results demonstrate that risk increase rate is not high in case of performing only ILRT test at every 5 years instead of doing GCLMS test at every 1.5 years. In addition, the result shows that GCLMS test can be removed on a risk-informed perspective since risk increasement is in acceptable area of regulatory acceptance criteria.

3D 카메라 기반 직업성 근골격계 부담 작업 모니터링 장치

노병국 ( Byoung Gook Loh ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.6

A 3D camera-based on-site work-related musculoskeletal disorder risk assessment(WMDs) tool has been developed. The device consists of Kinect a 3D camera manufactured by Microsoft, a servo-motor, and a mobile robot. To complement inherent narrow field of view(FOV) of Kinect, Kinect is rotated according to PID servo-control algorithm by a servo-motor attached underneath, to track movement of a subject, producing skeleton-based motion data. With servo-control, full 360 degrees tracking of a test subject is possible by single Kinect. It was found from experimental tests that the proposed device can be successfully employed for on-site WMDs risk assessing tool.

속도시간이력을 이용한 변위 추정 알고리즘에 관한 실험적 검증

조성호 ( Sung Ho Joh ),전준창 ( Jun Chang Jeon ),황선근 ( Seon Keun Hwang ),이희현 ( Hee Hyun Lee ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

In this study, displacement estimation algorithm, which is not requiring an absolute reference point unlike the conventional displacement measurement method, is developed using the geophone. To estimate displacement of the bridge, measured velocity time signal is integrated in the frequency domain. And, the estimated displacement is compared with the measured result using a conventional method. Based on the dynamic field test results, it was found that the estimated displacement by the present algorithm is similar to that of a conventional method. The displacement estimation algorithm proposed in this paper can be effectively applied to measure the displacement of a structure, which is difficult to install a displacement transducer at the fixed point.