• 대한안전경영과학회지
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• 제19권3호
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• pp.49-58
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• 2017

This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and POP(Point of Production) terminal through electronic document server and electronic pen, bluetooth receiver and form paper in disassembly and process inspection works. The proposed model shows that the new method by electronic document automation system can more efficiently perform to reduce processing time for maintenance work, compared with the current approach by handwritten processing system. It is noted in case of the method by electronic document automation system that the effects of proposed model are as follows; (a) While the processing time per equipment for maintenance by the current method was 300 minutes, the processing time by the new method was 50 minutes. (b) While the processing error ratio by the current method was 20%, the error ratio by the new method was 1%.

• 한국구조물진단유지관리공학회 논문집
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• 제27권2호
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• pp.77-84
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• 2023

태양광 패널의 설치가 가속화됨에 따라 사용수명이 종료된 태양광 패널도 증가하고 있다. 그러나 사용수명이 종료된 태양광 패널은 잠재적으로 위험한 물질을 포함하고 쉽게 재활용되지 않으므로 문제를 야기하고 있다. 사용수명이 종료된 태양광 패널의 효과적인 수거, 폐기 및 재활용 방법과 같은 대처 방안이 요구된다. 따라서 사용수명이 종료된 태양광 패널 재활용 기술 개발에 많은 연구가 진행되고 있다. 건설 분야에서 적용할 수 있는 태양광 패널의 재활용 기술 중 하나로, 사용수명이 종료된 태양광 패널에서 분리한 강화유리를 건설재료로 적용하는 것이 있다. 따라서 본 연구에서는 사용수명이 종료된 태양광 패널의 분리 기술을 정리하고 추출된 강화유리를 잔골재로 사용하여 모르타르의 역학적 성능을 평가하였다. 그 결과, 강화유리를 모르타르의 잔골재로 사용할 경우, 사용수명이 종료된 태양광 패널의 분리 기술과 관계없이 압축강도, 휨강도 및 1~3 ㎛, 200~300 ㎛ 범위의 거시공극이 영향을 받는 것으로 나타났다. 특히, 화학 처리된 강화유리를 사용한 모르타르는 화학반응으로 인해 소산된 K₂O와 CuO로 인해 주목할 만한 역학적 성능의 저하가 발생하는 것으로 나타났다. 한편, 플라이애시를 결합재로 사용할 경우, 모르타르의 역학적 성능 저하를 완화할 수 있는 것으로 판단된다.

• 비파괴검사학회지
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• 제13권3호
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• pp.24-30
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• 1993

원자력발전소 터빈 계통의 손상중에서 blade의 파손에 따른 원전의 불시 정지가 발생함에 따라 blade 균열 검출을 위한 초음파 검사의 필요성이 증가하고 있다. 그러나 터빈 blade root부 결함 탐지를 위한 초음파검사 방법은 그 형상의 복잡성으로 인하여 검사 기술이 아직 확립되지 자아 검사의 신뢰성 확보에 대한 많은 연구가 요망되고 있다. 본 연구에서는 터빈 blade에 인공 결함을 가공한 다음 초음파 검사시 복잡한 형상을 가진 blade root부 구멍 주위의 결함 검출 능력, skew angle 영향, 실제 결함과 기하학적 신호사이의 신호 구분에 대한 내용를 조사하였으며, 또한 RF 신호수집, 해석을 통하여 신호 분류 특성에 대한 연구도 병행하였다. 실험 결과 pin hole 주위의 초음파 균열 탐지를 위하여 인공 결함이 있는 blade 시편을 이용함으로 결함 검출을 위한 최적 검사조건의 도출이 가능하였고, blade의 복잡형상에 기인한 기하학적 영향을 줄이기 위해서는 skew angle 이 필수적인 것으로 나타났다. 따라서 본 연구 결과를 적용하면 blade root부위의 내부 균열 탐지를 위해 blade 를 해체함이 없이 현장 검사의 신뢰도를 제고할 수 있다.

• 한국정밀공학회지
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• 제29권5호
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• pp.524-530
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• 2012

In this study, it is performed that the assessment of feasibility of developed material processing facilities using tele-operation manipulator system for the pyroprocessing. To evaluate the performance of developed facilities using tele-operation system, several performance indices are considered as remote visibility, remote reachability and remote manipulability. These are applied to RHEM (Remote Handling Evaluation Mock-up) and digital mock-up system respectively. Through this approaches, several requirements for the system improvement are deduced and preliminary inspection for real system application is fully performed. Additionally, assembly and disassembly tasks for the repair of remote handling system are also examined remotely in RHEM and evaluated those performances.

• ETRI Journal
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• 제44권5호
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• pp.816-825
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• 2022

Nondestructive testing, which can monitor a product's interior without disassembly, is becoming increasingly essential for industrial inspection. Computed laminography (CL) is widely used in this application, as it can reconstruct a product, such as a printed circuit board, into a three-dimensional (3D) high-magnification image using X-rays. However, such high-magnification scanning environments can be affected by minute vibrations of the CL device, which can generate motion artifacts in the 3D reconstructed image. Since such vibrations are irregular, geometric corrections must be performed at every scan. In this paper, we propose a geometry calibration method that can correct the geometric information of CL scans based on the image without using geometry calibration phantoms. The proposed method compares the projection and digitally reconstructed radiography images to measure the geometric error. To validate the proposed method, we used both numerical phantom images at various magnifications and images obtained from real industrial CL equipment. The experiment results confirmed that sharpness and contrast-to-noise ratio (CNR) were improved.

• 대한기계학회논문집A
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• 제27권6호
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• pp.930-937
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• 2003

The extension of design life among power plants is increasingly becoming a world-wide trend. Kori #1 unit in Korea is operating two cycle. It has two man-ways for tube inspection in a steam generator which is one of the important components in a nuclear power plant. Especially, stud bolts fur man-way cover have damaged by disassembly and assembly several times and degradation for bolt materials for long term operation. It should be evaluated and compared by ASME Code criteria for integrity evaluation. Integrity evaluation criteria which has been made by the manufacturer is not applied on the stud bolts of nuclear pressure vessels directly because it is controlled by the yield stress of ASME Code. It can apply evaluation criteria through FEM analysis to damaged female threads and to evaluated safety fer helical-coil method which is used according to Code Case-N-496-1. From analysis results, we found .that it is the same results between stress intensity which got from FEM analysis on damaged female threads over 10％ by manufacture integrity criteria and 2／3 yield strength criteria on ASME Code. It was also confirmed that the helical-coil repair method would be safe.

• 품질경영학회지
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• 제51권2호
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• pp.297-313
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• 2023

Purpose: The purpose of this study is to investigate the causes of shifting errors reported in military tracked vehicles and to improve related quality to prevent recurrence. Methods: A systematic disassembly and inspection of the transmission is carried out and an experimental simulation is conducted to reproduce the shifting error phenomenon. Electrical characteristic tests are subsequently performed and microscopic observation is also carried out on the disassembled connector parts such as pins and fractured surfaces. Results: Oil contamination and swelling deformation are observed in the connector to the vehicle due to oil leakage of its counterpart connector to the transmission. This causes electrical contact failure between both connectors in the fastened state, and it is found that shifting error of the tracked vehicle could occur subsequently. To prevent the recurrence of this phenomenon, comprehensive quality improvement is conducted including product improvement of the wiring harness assembly and strengthening activities for quality control and preventive maintenance. Conclusion: This study is expected to be helpful as a prior case study for cause analysis and recurrence prevention in the event of similar cases in the future.