• 한국건설관리학회논문집
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• 제5권3호
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• pp.71-78
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• 2004

In conventional method of supporting soil shuttering wall during excavation a system of struts and wales to provide cross-lot bracing is common in trench excavations and other excavations of limited width. This method, however, becomes difficult and costly to be adopted for large excavations since heavily braced structural systems are required. Another expensive and unsafe situations are expected when temporary struts must be removed for the construction of underground structures. This paper introduces innovative strut systems which can be used as permanent underground structures after its role as brace system to resist earth pressure during excavation phase. Underground structural system suggested from architect is checked against the soil lated pressures before the analysis of stresses developed from gravity loads. In this technology, named SPS(Struts as Permanent System), retaining wall is installed first and excavation proceeds until the first level of bracing is reached. Braces used as struts during excavation will serve as permanent girders when buildings are in operation. Simultaneous construction of underground and superstructure can proceeds when excavation ends with the last level of braces being installed. In this paper, construction sequence and the calculation concept are explained in detail with some photo illustrations. SPS technology was applied to three selected buildings. One of them was completed and two others are being constructed Many sensors were installed to monitor the behavior of retaining wall, braces as column in terms of stress change and displacement. Adjacent ground movement was also obtained. These projects demonstrate that SPS technology contributes to the speed as well as the economy involved in construction.

• 보건의료산업학회지
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• 제6권2호
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• pp.211-217
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• 2012

To identify health behavior of Peptic ulcer patients among all employees in Korea and examine relevant factors to present basic data for improving Korean adult employees' health conditions and quality of living, 3,515 employees aged 20 to 69 were sampled from the group that responded to the question concerning the presence of Peptic ulcer in the fourth Korea National Health and Nutrition Examination Survey for the third year (2009). After logistic regression analysis was carried out to see the effects of working conditions, harmful factors, shift work, stress perception, and experience of depression on the presence of Peptic ulcer, it was found that unsafe or unpleasant working conditions led to higher risk of getting Peptic ulcer, that flexible workers were more likely to get Peptic ulcer, and that depression or stress perception exerted almost no effect on Peptic ulcer. With the increase in the number of flexible workers, increasingly more interest is taken in the effects of shift work on health; occupational Peptic ulcer tends to become chronic as compared with the condition in the general population and reappear even after recovery in many cases; therefore, it is necessary to take special management measures by estimating the number of those at a risk of getting Peptic ulcer and by finding out its risk factors.

• 산업경영시스템학회지
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• 제41권1호
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• pp.94-101
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• 2018

With the development of industrial technology and science, production and manufacturing facilities have been enhanced and improved, and the importance of the safety of workers has also been regulated and limited by various safety management methods. As a way to secure the safety of the workers from the production facility, the fail-safe and fool-proof methods are now being applied. Any possible insecure behavior and unsafe conditions can be removed by adopting the standards and specifications that are now secure the safety of workers and equipment. This research analyzes EN ISO 13849-1 international and European standards during CE certification. In order to secure acceptable reduced risks, the risk assessment process of ISO 12100 and the processes for reducing its risk are applied. In the current ISO 13849-1 standard, the criteria for the required performance level PLr (Required Performance Level) for the applicable risk and safety functions through the risk assessment are subjective and not subdivided. Therefore, the evaluation criteria are likely to cause judge's judgement error due to qualitative judgement. This research focuses on evaluation and acceptable performance level setting for the safety circuit of the equipment. We propose an objective and specific evaluation criteria to secure safety, and the proposed evaluation criteria are applied to the case study of the safety circuit for the equipment. In order to secure the safety of the entire safety circuit, the improvement of the MTTFd and DC level related to the SRP/CS (Safety-Related Parts of Control Systems)' lifetime is required for the future research.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.712-718
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• 2015

Cast duplex stainless steels are susceptible to thermal aging during long-term service at temperatures ranging from $280^{\circ}C$ to $450^{\circ}C$. To analyze the effect of thermal aging on leak-before-break (LBB) behavior, three-dimensional finite element analysis models were built for circumferentially cracked pipes. Based on the elasticeplastic fracture mechanics theory, the detectable leakage crack length calculation and J-integral stability assessment diagram approach were carried out under different bending moments. The LBB curves and LBB assessment diagrams for unaged and thermally aged pipes were constructed. The results show that the detectable leakage crack length for thermally aged pipes increases with increasing bending moments, whereas the critical crack length decreases. The ligament instability line and critical crack length line for thermally aged pipes move downward and to the left, respectively, and unsafe LBB assessment results will be produced if thermal aging is not considered. If the applied bending moment is increased, the degree of safety decreases in the LBB assessment.

• 대한안전경영과학회지
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• 제24권4호
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• pp.33-39
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• 2022

Safety has once again emerged as a social issue due to the enforcement of the Serious Disasters Punishment Act and the occurrence of major disasters recently. As such, the safety culture related to unsafe human behavior is drawing attention as various discussions about the importance of safety and accident prevention are currently being undertaken. This study aims to determine whether changes in the level of safety culture in companies affect the accident rate. To this end, we targeted three workplaces in the same company in the domestic manufacturing industry, and 2,790 people were surveyed using DNV's Safety Will(ISRS-C version 4.0) for safety culture level diagnosis. The change in safety culture level and accident rate were compared and analyzed after carrying out safety culture level improvement activities for 5 years. As a result, the level of safety culture increased by 5.8 points, an overall improvement of 9.5%, while the total number of accidents decreased by 20%, from 5 to 4, indicating a general decreasing trend in accident occurrence. Results confirmed that the change in the level of safety culture affects the accident rate, and the improvement in the level of safety culture affects a reduction in accidents. Therefore, this study suggests that efforts to improve the level of safety culture within a company can be associated with accident reduction and accident prevention outcomes.

• 문화기술의 융합
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• 제8권5호
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• pp.735-740
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• 2022

건설업은 사망자 수가 가장 많이 발생하는 산업이며, 다양한 제도 개선에도 사망자는 크게 줄어들지 않고 있다. 이에 따라, CCTV 영상에 인공지능(AI)을 적용한 실시간 안전관리가 부각되고 있다. 건설현장의 영상에 대한 AI를 적용한 근로자 탐지연구가 진행되고 있지만, 건설업의 특성상 복잡한 배경 등의 문제로 인해 성능 발현에 제한이 있다. 본 연구에서는 근로자의 탐지 및 자세 추정에 대한 성능 향상을 위해 YOLO 모델과 OpenPose 모델을 융합하여, 복잡 다양한 조건에서의 근로자에 대한 탐지 성능을 향상시켰다. 이는 향후 근로자의 불안전안 행동 및 건강관리 측면에서 활용도가 높을 것으로 예상된다.

• 국제학술발표논문집
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• The 10th International Conference on Construction Engineering and Project Management
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• pp.1057-1064
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• 2024

The construction industry has witnessed a concerning rise in ladder-related accidents, necessitating the implementation of stricter safety measures. Recent statistics highlight a substantial number of accidents occurring while using ladders, emphasizing the mandatory need for preventative measures. While prior research has explored computer vision-based automatic monitoring for specific aspects such as ladder stability with and without outriggers, worker height, and helmet usage, this study extends existing frameworks by introducing a rule set for co-workers. The research methodology involves training a YOLOv5 model on a comprehensive dataset to detect both the worker on the ladder and the presence of co-workers in real time. The aim is to enable smooth integration of the detector into a mobile application, serving as a portable real-time monitoring tool for safety managers. This mobile application functions as a general safety tool, considering not only conventional risk factors but also ensuring the presence of a co-worker when a worker reaches a specific height. The application offers users an intuitive interface, utilizing the device's camera to identify and verify the presence of coworkers during ladder activities. By combining computer vision technology with mobile applications, this study presents an innovative approach to ladder safety that prioritizes real-time, on-site co-worker verification, thereby significantly reducing the risk of accidents in construction environments. With an overall mean average precision (mAP) of 97.5 percent, the trained model demonstrates its effectiveness in detecting unsafe worker behavior within a construction environment.

• 한국조경학회지
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• 제39권2호
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• pp.65-72
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• 2011

일상적인 걷기활동과 신체활동은 노인들이 건강한 삶을 유지하는데 필수적인 활동으로, 걷기활동을 지원하고 참여를 촉진할 수 있는 물리적 환경의 제공의 중요성이 점점 커지고 있다. 본 연구는 도시 노인의 걷기활동의 참여 실태를 파악하고, 노인들의 걷기운동 수행과 관련성이 있는 개인적, 물리적 환경요인을 파악하는 것을 목표로 하였다. 이를 위해 수도권 지역의 60세 이상 노인을 대상으로 한 심층면접을 통하여, 일주일 동안의 이동목적이나 운동목적의 걷기활동 참여빈도와 시간을 측정하였으며, 행동변화 단계모델을 바탕으로 보다 정확한 걷기운동 수행 현황을 고찰하였다. 또한 공원 접근성, 보행로 시설, 교통시설 등 물리적 환경에 대한 인식과 만족도 및 평소 걷기활동에 장애가 되는 물리적인 요인들을 조사하였다. 분석결과, 과반수가 넘는 노인들이 규칙적인 걷기운동을 실천하고 있었으며, 행동변화 단계에 있어서는 6개월 이상 걷기운동을 지속하는 유지단계의 노인들 비율도 높았다. 걷기 운동장소로 선호되고 있는 곳은 도보권 내의 공원이나 산책로, 아파트 단지 등이 많았으며, 유료시설의 체육시설이나 실내 운동기구 이용은 상대적으로 낮았다. 또한 걷기운동 빈도에 유의적인 영향을 미치는 물리적 환경 요인으로는 공원접근성, 교통안전, 신호등, 가로등이 있었으며, 소득이 상대적으로 적은 노인들은 걷기운동에 대한 선호도가 보다 높은 것으로 파악되었다. 노인들은 교통안전에 대한 만족도를 매우 낮게 평가하였고, 교통사고에 대한 우려가 걷기활동에 있어 큰 장애가 되고 있는 것으로 조사되어, 노인시설을 중심으로 한 안전한 노인보행환경 개선이 시급한 것으로 나타났다. 본 연구는 도시 노인들의 일상적인 걷기활동 지원 및 증진을 위한 근린환경의 제공, 노인들의 걷기활동 지원 프로그램 마련에 필요한 기초자료를 제공할 수 있을 것으로 판단된다.

• 해양환경안전학회지
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• 제23권7호
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• pp.858-868
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• 2017

우리 조선업은 기술적인 분야에서 세계를 선도하는 역할을 수행하고 있으나 조선업에서는 매년 2,000여명의 재해자가 발생하고 있으며, 이중 약 40명은 사망하고 있는 등 근로자의 안전측면에서도 과연 우리 조선업이 세계적인 수준인지는 의문이 들 수밖에 없다. 따라서 이 연구는 국내 조선업에서 2006년~2015년 동안 발생한 중대재해의 통계자료를 고찰하여 조선업 중대재해의 발생현황 및 원인을 분석하고, 조선업 근로자를 대상으로 설문조사를 실시하여 산업현장에서의 안전교육 형태를 분석하였으며, 이를 바탕으로 조선업 안전교육의 문제점을 도출하여 개선방안을 마련하였다. 첫째, 조선소별로 수행하는 안전교육의 종류 및 수준이 상이하거나 교육품질이 미흡한 문제점을 해결하고 체계적으로 교육과정을 운영하기 위해서 조선업 안전훈련 표준체계의 마련이 필요하다. 둘째, 조선업 안전훈련 표준체계를 바탕으로 조선업에 특화된 안전교육과정을 지속적으로 개발하고 표준화하여 조선업 중대재해를 감소시키고 근로자의 안전의식을 향상시킬 필요가 있다. 셋째, 조선업에서의 중대재해를 예방하여 근로자의 안전을 확보하기 위해서는 사업주와 근로자 모두가 적극적으로 안전교육을 수행하고 참여하여 사업장의 안전문화를 형성할 필요가 있다.

• 한국해안·해양공학회논문집
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• 제35권6호
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• pp.128-137
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• 2023

본 연구는 비정형 바닥판을 갖는 중력식 구조물의 사석마운드 지반반력을 대상으로 하였다. 구조물 바닥을 강체로 가정하고, 사석마운드는 압축에 대해서만 저항하는 바닥에 균일하게 분포하는 선형스프링으로 모형화하여 지반반력 산정식을 유도하였다. 바닥 형상이 사각형인 경우, 그 유도된 식이 설계에 사용되고 있는 식으로 변환됨을 보임으로써 유도 과정에 오류가 없음을 확인하였다. 또한, 비정형 바닥 형상이 사각형으로 수렴할 때의 지반반력의 거동과 그 수렴값을 살펴봄으로써 유도된 식의 타당성을 입증하였다. 실제 설계에서 사용되고 있는 방법의 적정성을 살펴보기 위하여 기 설계된 방파제 단면에 대한 단부 지반반력을 계산하고 설계서에 제시된 값과 비교하였다. 그 결과, 설계에 사용한 방법이 비안전측의 결과를 주었다는 것을 확인하였다. 특히, 극한 설계조건의 경우와 같이 연직하중의 편심이 큰 경우에 그 차이가 더 크게 나타났다.