• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.87-88
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• 2022

For an earthquake-safe urban environment, the Republic of Korea conducts seismic performance evaluation in accordance with laws and guidelines to assign safety ratings and implement necessary management measures such as repairs and reinforcements. In the seismic performance evaluation result, structures lacking in preparation for earthquakes are prioritized and classified into measures such as repair, reinforcement, or careful observation to respond to physical risks such as earthquakes. Such repair and reinforcement work is not a one-time thing, but it is necessary to further enhance the effect through continuous follow-up observation. In this study, the location of the vertical and horizontal displacement measuring part of the construction part is displayed so that the post-construction status of the reinforcement construction part can be visually checked by identifying the problems in the process of post-monitoring in 2022 for the maintenance and reinforcement work of local governments' public facilities carried out in 2021. We propose a plan to institutionalize the installation of, inspection tools, and crack gauges at certain locations in the construction department, and to have facility managers periodically inspect and manage them with a smartphone program or the 'Facility Autonomous Safety Inspection' app.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2348-2356
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• 2021

As a relatively new radiation imaging method, the cosmic-ray muon scattering imaging technology can be used to prevent nuclear smuggling and is of considerable significance to nuclear safety. Proposed in this paper is a new reconstruction algorithm based on density clustering, aiming to improve inspection quality with better performance. Firstly, this new algorithm is introduced in detail. Then in order to eliminate the inequity of the density threshold caused by the heterogeneity of the muon flux in different positions, a new flux correction method is proposed. Finally, three groups of simulation experiments are carried out with the help of Geant4 toolkit to optimize the algorithm parameters, verify the correction method and test the inspection quality under shielded condition, and compare this algorithm with another common inspection algorithm under different conditions. The results show that this algorithm can effectively identify and locate nuclear material with low misjudging and missing rates even when there is shielding and momentum precision is low, and the threshold correcting method is universally effective for density clustering algorithms.

• 한국구조물진단유지관리공학회 논문집
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• 제17권3호
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• pp.97-107
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• 2013

배수통문은 하천제방을 횡단하여 설치된 하천시설로, 연속적으로 시공되어져야 하는 제방의 특성에 반하여 불연속적인 단면을 제공함으로써 하천제방 안전성을 저하시키는 구조물로 알려져 있다. 본 논문에서는 배수통문의 효율적인 점검 체계 구축을 위하여 육안점검표 및 휴대용 단말기를 이용한 육안조사 시스템을 제시하고 향후 개선방향을 제시하였다. 제안된 육안점검표는 적용성 평가결과 간단한 육안점검에 의한 손상 파악을 통해 배수통문의 보수 계획 수립과 보수 및 정밀안전진단에 대한 투자우선순위 선정에 적용성이 높은 것으로 평가되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.667-670
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• 2001

For major structural components periodic inspections and integrity assessments are needed for the safety. However, many flaws are undetectable because sampling inspection is carried out during in-service inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties and undetectable cracks. This paper describes a Probabilistic Fracture Mechanics(PEM) analysis based on the Monte Carlo(MC) algorithms. Taking a number of sampling data of probabilistic variables such as fracture toughness value, crack depth and aspect ratio of an initial surface crack, a MC simulation of failure judgement of samples is performed. For the verification of this analysis, a comparison study of th PFM analysis using a commercial code, mathematical method is carried out and a good agreement was observed between those results.

• 농업과학연구
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• 제49권4호
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• pp.707-717
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• 2022

As the variability of recent rainfall is increasing, it is becoming important to recognize the possibility of changes in the current reservoir state in advance and to inspect the stability based on accurate evaluation standards. However, the evaluation standards for the state change factors of reservoirs are still not suitable for agricultural reservoirs and thus much improvement is needed. Therefore, in this study, the evaluation criteria for state change factors specialized for small reservoirs were categorized and standards were prepared by considering factors that may cause state changes on the dam crest, upstream slope, and downstream slope of the embankment. The categorized results were configured based on the number of mentions of the precision safety inspection report on major defects in 102 reservoirs and the defect factors found in field investigations. The findings of the study indicated that the current state change standards require many revisions for excessive or unnecessary state change factors in the reservoir. Specifically, the deletion of measurement gauges not applicable to the reservoir, the addition of defects found in the reservoir, and the scope of use of the term were proposed. The results of this study can contribute to efficient system operation and management by improving the deficiencies in the system and introducing a new state change factor.

• Journal of Ship and Ocean Technology
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• 제11권1호
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• pp.36-46
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• 2007

The maintenance of a ship is essential for safe navigation and hence regular surveys are prescribed according to the rule of classification societies. A hull inspection is generally performed by professional divers, but it takes a long time and the efficiency is low in terms of time and cost. In this research, a ROV(Remotely Operated Vehicle) named as SNU-ROV(Seoul National University-ROV) is developed to replace the conventional inspection method. In this system, the ROV is intended to be used for inspecting ship and harbor because harbor inspection is merging as a safety measure against any possible terror actions. In order to increase the efficiency of inspection, the ROV must be able to measure the exact position of damages. SNU-ROV has a positioning system based on LBL(Long Base Line). In shallow water such as harbor, however, LBL has bad DOP(Dilution of Precision) in the depth direction due to the limited depth. Thus LBL only can not locate the exact depth position. To solve the DOP problem, a pressure sensor is introduced to LBL and a complementary filter is attached by using indirect feedback Kalman filter. Thus developed positioning system is verified by simulation and experiment in towing tank.

• 교육녹색환경연구
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• 제18권1호
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• pp.38-48
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• 2019

본 연구는 대학 연구실 사고 예방을 위해서 실험 전 이루어지는 형식적인 일상점검을 보다 실효성 있는 일상점검표를 제시하는데 목적이 있다. 이를 위해 현재 실시중인 일상점검표와 선행연구자료를 재구성하여, 이를 토대로 2차에 걸친 전문가 델파이 조사로 연구를 실시하였다. 그 결과 연구실 정리정돈 등 일반안전 4개, 기계 및 공구 조임부 이상여부 등 기계기구안전 3개, 전기분전반 주변 적재금지 등 전기안전 3개, 유해인자취급 및 관리대장 비치 등 화공안전 6개, 소화기 점검 등 소방안전 3개, 가스용기 점점 등 가스안전 5개, 손 소독기 관리상태 등 생물안전 1개, 기타 1개, 총 26개 항목을 일상점검표로 제시하였다. 관련 전문가들의 의견을 종합해 보면, 실질적인 일상점검을 위해서는 쉽고 간소화 된 일상점검표가 필요한 것으로 나타났다.

• 한국식품위생안전성학회지
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• 제38권3호
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• pp.89-98
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• 2023

현재, 국내에서는 가공식품인 식용유지에 대한 잔류농약 허용기준이 설정되어 있지 않아 잔류농약은 식용유 품질평가의 사각지대라 할 수 있다. 본 연구에서는 식용유지에서 가열증류법을 이용하여 68종의 농약을 대상으로 추출 및 정제법을 최적화하여 GC-MS/MS 분석법을 확립하였다. 가열증류법은 가열온도 및 시간의 영향을 받았으며 이동상의 역할을 하는 질소의 유량과 용출용매의 종류에는 큰 영향을 받지 않는 것으로 나타났다. 본 연구에서 잔류농약의 결정계수(R²)는 0.99 이상으로 나타났고, 정량한계(LOQ)는 0.01-0.02 mg/L이었으며, 대두유를 이용하여 0.01, 0.02, 0.1, 0.5 mg/L 수준으로 회수율 실험 결과 평균 회수율(n=5)은 66.1-120.0%이었고 상대표준편차는 ±10%이하로 나타났다. 또한 실험실내 일간정밀도는 11%이하로 조사되어, 식품의약품안전평가원의 '식품등 시험법 마련 표준절차에 관한 가이드라인(2016)'에 적합한 수준임을 확인하였다. 따라서 본 연구에서 개발한 시험법은 식용유지의 잔류농약 안전관리를 위한 시험법으로 활용이 가능할 것으로 기대된다.

• 한국산업융합학회 논문집
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• 제25권4_2호
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• pp.573-586
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• 2022

Corrosion can cause dangerous and expensive damage and failures of ship hulls and equipment. Therefore, it is necessary to maintain the vessel by periodic corrosion inspections. During visual inspection, many corrosion locations are inaccessible for many reasons, especially safety's point of view. Including subjective decisions of inspectors is one of the issues of visual inspection. Automation of visual inspection is tried by many pieces of research. In this study, we propose image preprocessing methods by image patch segmentation and thresholding. YOLOv5 was used as an object detection model after the image preprocessing. Finally, it was evaluated that corrosion detection performance using the proposed method was improved in terms of mean average precision.

• 한국건설관리학회논문집
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• 제15권2호
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• pp.62-70
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• 2014

민간시설물인 공동주택은 한 건축물 안에 다수의 인원이 각각 독립생활을 할 수 있도록 지어진 주택으로서 부실점검에 의한 건축물 안전사고 발생 시 인명피해가 제일 많이 발생할 수 있는 건축물이다. 하지만 관리주체의 안전점검에 대한 의식부족 및 최저가입찰방식에 의한 진단업체의 저가수주 등으로 인해 형식적인 점검이 이루어지고 있는 실정으로 향후 구조물의 유지관리 등 보수 보강 시 막대한 대가가 투입되고, 구조물의 안전사고 발생 시 인적피해를 유발할 가능성이 크다고 판단된다. 이에 본 논문은 효율적인 정밀점검 수행을 위한 현행 기준의 개선점을 도출하고자 광주광역시 및 전라남도 지역의 2종 시설물에 대하여 최근 3년간 실시한 정밀점검 대상건축물 66개동의 설계대가 및 실행대가현황을 조사 분석한다. 이를 통해 2차 대상건축물을 선정하고, 선정 된 공동주택 10개 단지의 정밀점검 보고서 및 정밀점검 실행대가 산정 기준을 평가하여 현행 문제점 분석을 통한 개선점을 제시하고자 한다.