http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
용접 시험편의 디지털 방사선 검사에서 밝기 교정과 중첩 영상에 따른 SNR 및 SRb 비교 연구
남문호(Mun-Ho Nam),양진욱(Jin-Wook Yang),조갑호(Kap-Ho Cho) 한국방사선학회 2021 한국방사선학회 논문지 Vol.15 No.5
이 연구는 산업현장에서 구조물의 용접부 검사를 디지털 방사선을 이용한 비파괴검사를 효과적으로 수행할 수 있도록 디지털 방사선의 밝기 교정과 중첩 영상에 따른 신호 대 잡음 비와 기본 공간 분해능을 비교분석 하였다. 평판형 용접 시험편을 대상으로 75Se 방사선원을 사용하였고 촬영 전 밝기 교정과 영상 중첩을 세분화하여 총 130장의 영상을 획득하였다. 연구 결과, 밝기 교정의 수와 영상 중첩의 수가 증가할수록 신호 대 잡음 비가 향상됨을 확인하였다. 기본 공간 분해능은 촬영된 영상 모두 기준치를 만족하였다. 산란 방사선을 대비한 납 차폐를 설치 후 촬영한 영상을 비교하여 신호 대 잡음 비가 비슷함을 확인하였다. 영상 중첩이 증가할수록 신호 대 잡음 비가 증가하지만, 방사선의 노출시간이 증가하면서 작업자의 피폭 및 작업 효율에 영향을 미치기 때문에 적절한 촬영기법을 강구 한다면 좋은 상질의 디지털 방사선 영상을 획득 할 수 있을 것으로 사료된다. This work compared the bright calibration of digital radiation with signal-to-noise ratio and basic spatial resolution according to multi frame to enable effective inspection of welding parts of structures at industrial sites. A total of 130 images were obtained by using a 75Se radiation source for flat weld test pieces and segmenting bright calibration and multi frame prior to shooting. The study confirms that the signal-to-noise ratio improves as the number of bright calibrations and the number of multi frame increases. The basic spatial resolution satisfied the baseline for both radiographic images. It was confirmed that the number of signal-to-noise ratio was similar by comparing images taken after installing lead shielding for scattering radiation. Although signal-to-noise ratio increases as multi frame increases, it is believed that good quality digital radiographs can be obtained if appropriate radiographic techniques are devised because exposure time of radiation affects workers exposure and work efficiency.
항공우주 산업용 알루미늄 주강품 검사를 위한 실시간 Digital Radiography System 개발
남문호(Mun-Ho Nam),장훈(Hoon Jang),박성욱(Seong-Wook Park),정찬수(Chan-Soo Chung) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.7
As the aerospace industy grows, more intensive methods are introduced to the examination of important parts. In case of blade aluminum casting, conventional radiographic testing is performed in general. But in this study, a digital radiography system was developed for more precise examination. Using the developed system, digital images were acquired and after image processing, evaluation was given to verify the conformance to prevailing quality requirements and examination standards.
위상배열 탐상검사법을 이용한 풍력발전용 블레이드의 일정가압 메커니즘 신뢰성 평가
남문호(Mun Ho Nam),지수정(Su Chung Chi),임선(Sun Lim),임승환(Seung Hwan Lim),정예찬(Ye Chan Jeong) 한국신뢰성학회 2017 신뢰성응용연구 Vol.17 No.3
Purpose: There is no established inspection system for composite wind blade during the fabrication stage even though the blades are one of the most important part at wind generation system, but phased array ultrasonic testing method has been continuously studied about wind turbine blade with composite. When wind turbine blade with complex shape by phased array probe is inspected, it is necessary to study for system keeping constant pressure using pressure device. Methods: In this paper, we propose constant pressure device for inspecting wind turbine blade by phased array ultrasonic test method. Design of the device controller is based on Hunt-Crossley model. We evaluate reliability of phased array ultrasonic inspection result that applicated constant pressure device. Result: Defect indication is precise and its error is small when constant pressure mechanism based on Hunt-Crossley model was used. Conclusion: When inspection is progressed using constant pressure mechanism, the reliability of composite wind blade inspection can be improved.
풍력발전용 복합소재 블레이드의 적외선 열화상 검사를 이용한 신뢰성 검증
강병권(Byung Kwon Kang),남문호(Mun Ho Nam),임익성(Ik Sung Lim) 한국신뢰성학회 2014 신뢰성응용연구 Vol.14 No.3
In these days, new and renewable energy is getting popular around globe and wind power generator is one of the renewable energy. In this study, we conducted a study on defect detection of composite material blade for wind power generator by applying active infrared thermography and produced a defect test piece by applying composite material used for blade of wind power generator. An infrared thermal camera and 2 kW halogen lamp are used for the purpose of research as equipments. Also, we analyzed temperature characteristic by using infrared thermal camera after checking a heat source on a test piece and found effectiveness of infrared thermography to blade of wind power generator by detecting defects resulting from temperature difference of a test piece, which eventually improve the safety and reliability of the composite material blade.