• Structural Engineering and Mechanics
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• 제64권3호
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• pp.347-352
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• 2017

The poor maintenance practice increases the possibility of system failure. Subsequently, the consequences of failure fall on the aspects of output, safety and healthy, environmental integrity, system quality, and customer satisfaction. Conditionbased maintenance is seen as a potential strategy to improve performance. Whereby, the key success factor of this maintenance strategy is identified as the system inspection. This study aims to investigate the association between system breakdown rate and frequency of inspection. A mixed method approach is implemented by distributing questionnaire and interviewing for data collection. Subsequently, descriptive analysis, correlation analysis and regression are adopted to analyse the collected data from 100 respondents and the results are validated with interview data of 10 interviewees. The research result establishes significant relationship between the system breakdown rate and the frequency of inspection. Additionally, the result of regression analysis confirms that the frequency of inspection is the significant predictor of system breakdown rate. Planning of accurate inspection frequency is crucial to secure the system performance. Hence, the research signifies the importance to carry out regular inspection towards the building systems and components. As a recommendation, the maintenance personnel should assess the risk criticality of the building systems. Then, continuously monitor the condition of critical building systems; regularly inspect the condition of non-critical building systems and randomly inspect all of them.

• Structural Monitoring and Maintenance
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• 제2권3호
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• pp.283-300
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• 2015

Visual condition inspections remain paramount to assessing the current deterioration status of a bridge and assigning remediation or maintenance tasks so as to ensure the ongoing serviceability of the structure. However, in recent years, there has been an increasing backlog of maintenance activities. Existing research reveals that this is attributable to the labour-intensive, subjective and disruptive nature of the current bridge inspection method. Current processes ultimately require lane closures, traffic guidance schemes and inspection equipment. This not only increases the whole-of-life costs of the bridge, but also increases the risk to the travelling public as issues affecting the structural integrity may go unaddressed. As a tool for bridge condition inspections, Unmanned Aerial Vehicles (UAVs) or, drones, offer considerable potential, allowing a bridge to be visually assessed without the need for inspectors to walk across the deck or utilise under-bridge inspection units. With current inspection processes placing additional strain on the existing bridge maintenance resources, the technology has the potential to significantly reduce the overall inspection costs and disruption caused to the travelling public. In addition to this, the use of automated aerial image capture enables engineers to better understand a situation through the 3D spatial context offered by UAV systems. However, the use of UAV for bridge inspection involves a number of critical issues to be resolved, including stability and accuracy of control, and safety to people. SLAM (Simultaneous Localisation and Mapping) is a technique that could be used by a UAV to build a map of the bridge underneath, while simultaneously determining its location on the constructed map. While there are considerable economic and risk-related benefits created through introducing entirely new ways of inspecting bridges and visualising information, there also remain hindrances to the wider deployment of UAVs. This study is to provide a context for use of UAVs for conducting visual bridge inspections, in addition to addressing the obstacles that are required to be overcome in order for the technology to be integrated into current practice.

• 한국농공학회논문집
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• 제63권5호
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• pp.27-38
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• 2021

The physical condition assessment criteria of fill dam safety inspection are now weakly regulated and inappropriate for small agricultural reservoirs since these criteria have fundamental backgrounds suitable for large-scale dams. This study proposes the degree (critical values) of defects for the quantitative condition assessment of the embankment in order to prepare the condition assessment criteria for a small reservoir with a storage capacity of less than one (1) million cubic meters. The critical values of defects were calculated by applying the method that considers the size ratios based on the dimensional data of reservoirs, and the method of statistical analysis on the measured values of the defect degree which extracted from comprehensive annual reports on reservoir safety inspection. In comparison with the current criteria, the newly proposed critical values for each condition assessment item of the reservoir embankment are presented in paragraphs 4 and 6 of the conclusion. In addition, this study presents a method of displaying geometric figures to clarify the rating classification for condition assessment items with the two defect indicators.

• 상하수도학회지
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• 제30권6호
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• pp.623-634
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• 2016

Sewer condition assessment involves the determination of defective points and status of aged sewers by a CCTV inspection according to the standard manual. Therefore, it is important to establish a reliable and effective standard manual for identifying the sewer defect. In this study, analytic reviews of the CCTV inspection manuals of the UK, New Zealand, Canada and South Korea were performed in order to compare the defect codes and the protocols of condition assessment. Through this, we also established the standardized method for defect code and revised the calculation method of assigning the condition grade. Analyses of the types and frequencies of sewer defects that obtained by CCTV inspection of 7000 case results, showed that the joint defect and lateral defect were the most frequent defects that occurred in Korea. Some defect codes are found to be modified because those did not occur at all. This study includes a proposed new sewer defect codes based on sewer characteristics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.11-13
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• 2007

The appearance inspection of various electronic products and parts has been executed by the eyesight of human. But inspection by eyesight can't bring about uniform inspection result. Because the appearance inspection result by eyesight of human is changed by condition of physical and spirit of the checker. So machine vision inspection system is currently used to many appearance inspection fields instead of the checker. However the inspection result of machine vision is changed by the illumination of workplace. Therefore we have used a power-law transformation in this paper. for improvement of vision inspection accuracy and could increase inspection accuracy of vision system. Also this system has been developed only using PC, CCD Camera and Visual C++ for universal workplace.

• 한국구조물진단유지관리공학회 논문집
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• 제23권4호
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• pp.1-7
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• 2019

국가 주요 시설물의 안전점검 업무가 일원화됨에 따라 업무 효율성과 전문성 강화 등의 효과가 기대되고 있다. 세계적으로 시설물의 물리적 기능적 결함을 초기에 발견하는 외관조사의 중요성이 강조되고 있다. 이에 본 연구에서는 기존 외관조사 방법의 문제와 한계를 극복하기 위해 시설물 안전점검을 위한 E-PAD기반 상태평가 시스템을 개발하였다. 본 시스템은 시설개요, 작업목록, 외관조사, 결함표로 구성되어 있으며, 현장에서 외관조사망도를 다운받아 조사된 손상 및 정보를 입력하고, 평가 등급을 확인할 수 있다. 본 시스템의 검증을 위해 교량 10개소에 대한 외관조사 데이터를 입력하여 기존 안전등급을 비교하였다. 그 결과 시스템에서 산출된 안전등급과 기존 안전등급이 동일한 것으로 확인되었다. 또한 AHP기법을 통해 타당성 분석 결과 기존 방법 대비 기능 10%증가, 비용 36%감소, 가치 30%증가한 것으로 분석되었다. 따라서, 시설물 관리 수준 향상을 위해 체계적인 데이터 구축 및 정보 분석을 위한 시스템으로 기여할 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.123-124
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• 2008

The appearance inspection of various electronic products and parts has been executed by the eyesight of human. But inspection by eyesight can't bring about uniform inspection result. Because the appearance inspection result by eyesight of human is changed by condition of physical and spirit of the checker. So machine vision inspection system is currently used to many appearance inspection fields instead of the checker. Therefore we proposes a inspection system in this paper. it will be able to secure the objectivity of the prosecuting attorney using inspection system. Also this system has been developed only using PC, CCD Camera and Visual C++ for universal workplace.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.172-173
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• 2021

In recent, unmanned Aircraft Systems (UAS) have been widely used for various purposes, such as safety inspection, facility condition inspection, progress monitoring, in the architecture engineering, and construction (AEC) industry. This technology can provide visual assets regarding the conditions of construction jobsites as well as constructed facilities during flying over the point of interests. With the significant interests in this advancement, the recent studies have presented how the UAS can be applied fro different types of facilities (e.g., buildings, power genereation systems, roads, or bridges) to inspect the current conditions of them for safe operations as well as public's safety. This study reviewed the receent studies to document their scientific findings and practical contributions, as well as provided the overview of further implications for future studies.

• 한국안전학회지
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• 제21권2호
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• pp.114-120
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• 2006

Inspection works are mainly carried out with the help of human sensory organs and are relatively simple and repetitive, so that the workers easily become to feel fatigue and monotony, and their mental activity levels attenuate. Consequently, during the work time, it is natural that various lighting conditions around the workplaces may have in-fluence on work performance. This study aimed to analyze cortical fatigue of inspection workers. Thus, an inspection work was simulated on a computer monitor under various lighting conditions, and CFF, EEG, EOG, and HRV were analyzed. According to the results, fatigue symptoms turned up about $60{\sim}90$ minutes after the onset of the work. The work performance also decreased when the fatigue symptoms due to lighting conditions turned up. The variations of fatigue and work performance were affected by illuminators, illumination levels, or interaction of those two factors. The spiral fluorescent lamp seemed improper to the inspection work, because the work performance under that condition was lower than under any other illuminators.

• 전자공학회논문지SC
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• 제44권5호
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• pp.11-17
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• 2007

각종 전자 제품 및 부품의 외관 검사는 사람의 시각에 의해 이루어졌다. 그러나 사람의 시각에 의한 외관 검사 결과는 검사자의 육체적, 정신적 상태에 따라 변하기 때문에, 일정한 검사 결과를 얻을 수 없다. 따라서 사람에 의한 검사 대신 머신 비전 검사 시스템이 많은 외관 검사 분야에 사용되고 있다. 그러나 머신 비전 시스템의 외관 검사 결과는 작업장의 조명에 의해 변하게 된다. 이에 본 논문에서 우리는 비전 검사 정확도의 개선을 위해 멱함수 변환과 히스토그램 지정 기법을 사용했다. 그리고 멱함수 변환과 히스토그램 지정 알고리즘을 통해서 비전 검사의 정확도를 향상시키고, 검사자의 육체적, 정신적 상태에 따른 검사 오류를 막을 수 있었다. 또한 이 시스템은 일반적인 검사 환경을 위해서 PC, CCD 카메라와 비주얼 C++ 만을 사용해서 개발됐다.