자기애자의 유지 관리를 위한 CNN 기법을 이용한 이미지 분석

최인혁,신구용,구자빈,손주암,임대연,오태근,윤영근,Choi, In-Hyuk,Shin, Koo-Yong,Koo, Ja-Bin,Son, Ju-Am,Lim, Dae-Yeon,Oh, Tae-Keun,Yoon, Young-Geun 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.3

This study examines the feasibility of the image deep learning method using convolution neural networks (CNNs) to maintain a porcelain insulator. Data augmentation is performed to prevent over-fitting, and the classification performance is evaluated by training the age, material, region, and pollution level of the insulator using image data in which the background and labelling are removed. Based on the results, it was difficult to predict the age, but it was possible to classify 76% of the materials, 60% of the pollution level, and more than 90% of the regions. From the results of this study, we identified the potential and limitations of the CNN classification for the four groups currently classified. However, it was possible to detect discoloration of the porcelain insulator resulting from physical, chemical, and climatic factors. Based on this, it will be possible to estimate the corrosion of the cap and discoloration of the porcelain caused by environmental deterioration, abnormal voltage, and lightning.

Mixed steam and carbon dioxide reforming of methane on Ni CeO2/MgAl2O3 catalyst: the performance of pelletized catalyst

최인혁,전기원,이윤조,백승찬,박해구 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

주파수응답함수(FRF)를 이용한 자기 애자의 손상평가

최인혁,손주암,오태근,윤영근 한국전기전자재료학회 2019 전기전자재료학회논문지 Vol.32 No.2

Porcelain insulators have been used mainly for power line fixing and electrical insulation in transmissiontowers. Porcelain insulators have generally a 30 years desired life, but over 50% exceed their life expectancy. Since thedamage to porcelain insulators is usually accompanied by enormous loss of human resource material, their efficientmaintenance has emerged as an important issue. In this regard, this study applied a frequency response function (FRF)for integrity assessment of the insulator. The characteristics of the FRF according to damage types were identified andanalyzed by the change in natural frequencies, curve shape, attenuation, and Nyquist diagram stability. The resultsshowed significant differences in the FRF according to damage types, which can be used as basic data for the effectiveintegrity assessment of porcelain insulators. 자기애자는 송전탑의 전력선 고정 및 전기적 절연을 위해 사용된다. 자기애자는 사용수명이 30년으로 제작되었지만, 현재 제작수명을 넘어선 애자는 전체의 50%를 상회한다. 자기애자의 손상으로 발생되는 손실은 막대한 인적, 물적 피해를 동반하기 때문에 자기애자의 건전성을 평가하는 방법이 중요한 쟁점으로 떠오르고 있다. 이에 따라 비파괴 검사기법 중 FRF를 활용하여 자기애자의 건전성을 평가하기 위한 방법으로 적용하였다. 본 연구에서는 자기애자의 고유모드 주파수, 곡선 형상, 감쇠 및 나이퀴스트 선도 안정성 분석을 통해 손상유형에 따른 특성을 분석하였다. 본 연구결과를 통해 자기애자의 건전성 평가를 위한 기초자료로 쓰일 수 있기를 기대한다.

자기애자의 자기부 균열 식별을 위한 이미지 처리기법 개발

최인혁,신구용,안호성,구자빈,손주암,임대연,오태근,윤영근 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.4

This study proposes a crack identification algorithm to analyze the surface condition of porcelain insulators and to efficiently visualize cracks. The proposed image processing algorithm for crack identification consists of two primary steps. In the first step, the brightness is eliminated by converting the image to the lab color space. Then, the background is removed by the K-means clustering method. After that, the optimum image treatment is applied using morphological image processing and median filtering to remove unnecessary noise, such as blobs. In the second step, the preprocessed image is converted to grayscale, and any cracks present in the image are identified. Next, the region properties, such as the number of pixels and the ratio of the major to the minor axis, are used to separate the cracks from the noise. Using this image processing algorithm, the precision of crack identification for all the sample images was approximately 80%, and the F1 score was approximately 70. Thus, this method can be helpful for efficient crack monitoring. 본 연구에서는 자기 절연체의 표면 상태를 분석하고 효율적으로 균열을 시각화하기위한 균열 식별 알고리즘을 제안한다. 균열 식별을 위해 제안 된 이미지 처리 알고리즘은 두 가지 주요 단계로 구성된다. 첫 번째 주요 단계에서 Lab 색상 변환으로 밝기를 제거한 다음 K- 평균 군집화 방법으로 배경을 제거한다. 그 후, 블롭 (blob)과 같은 불필요한 노이즈를 제거하기 위해 형태 학적 이미지 처리 및 중간 필터로 최적의 이미지 처리가 적용되었다. 제 2 주요 단계에서, 효율적인 식별을위한 전처리 된 이미지가 그레이 레벨로 변경되고, 균열의 존재가 식별된다. 다음으로, 크랙과 노이즈 사이의 분리를 위해 픽셀 수 및 장축 대 단축의 비율과 같은 영역 특성이 적용된다. 이미지 처리 결과 모든 샘플 이미지에 대한 균열 식별의 정밀도는 약 80 %이고 F1 점수는 약 70입니다. 따라서이 방법은 효율적인 균열 모니터링에 도움이 될 수 있다.

全北地方 乳牛의 繁殖障害에 대한 實態調査(Ⅱ)

崔仁赫 全北大學校 1975 論文集 Vol.17 No.-

Three hundreds and seventy eight heads of milk cow from 83 dairy farms were examined in order to investigated the status of reproductive disorders. The results are as follows : 1. Thirty three heads of milk cow(8.73%) were reported as the status of reproductive disorders by the owner but only 13 heads (3.46%)were identified as the result of examination actually. 2. Classification of 13 cows of reproductive disorders is as follow :Ovarian cyst 23.08%, Persistant corpus luteum 7.69%, Ovarian atrophy 7.69%, Endometritis 15.38%, Silent heat 7.69%, Repeat breeders 15.38%, Follicular hypoplasia 23.08%, 3. Three hundreds seventy eight heads of milk cows were bred in 83 dairy farms and average number of cow per farm were 4.6 heads and their owner bred cows from 1 head to 29 heads in one farm.

Fabrication of Thermoresponsive Hydrogel and Conjugated Polymer Composites

최인혁,전석진 한국고분자학회 2020 한국고분자학회 학술대회 연구논문 초록집 Vol.45 No.2

동결건조한 산양뼈의 개이식 효과

최인혁,이종일 한국임상수의학회 1998 한국임상수의학회지 Vol.15 No.2

Freeze-dried cortical bones of the goat were transplanted to the experimental fibular defect of 10 dogs for valuating the possibility of xenogeneic bone implantation and the specificity of BM(Bone Morphogenetic Protein). The . freeze-dried cortical bone eliminated antigens and defatted with chloroform and methanol were freeze-dried at $-80{\circ}C$ for preservation of BMP and then sterilized with 50 gas and storaged in room temperature. Ten freeze-dried cortical implants of the goat were transplanted in experimentally defected regions of bilateral fibula of 5 dogs in clinically normal. The transplanted region had been radiographed for observing state of bone union and BALPOone Alkaline Phosphatase) in the serum of the host was measured for valuating activity of oteoblast per 2 week-interval after transplant procedures. New bone formation had been observed early in one of ten regions around implants about the same time as autoimplant regions. It was incorporated with its host bone during 4-12 weeks after transplantation. In another 2 cases of 2 dogs, new bone formation and absorption of implant had been observed from 4 weeks but they were not incorporated completely until 20 weeks. The rest of the freeze-dried bone implants, 7 cases of 4 dogs had not been observed new bone formation nor absorption of implants. The freeze-drying method for implants means to not influence bone incorporation. Although less of union percentages the union form of this experiment were similar to alloimplantation and it may mean to block immunity reaction that disturbs the bone induction by BMP. It demonsknted that the possibility of the xenogenous bone implantation is recognized by reason of the low specificity of BMP between goat and dog.

캐릭터상품 유통구조 개선을 위한 종합유통센터 설립에 관한 연구

최인혁,오동욱 한국유통학회 2003 한국유통학회 학술대회 발표논문집 Vol.- No.-

창의적 문제해결 모형을 적용한 미술활동이 영재와 일반아동의 창의력, 공간능력, 도형유추능력에 미치는 영향

최인혁,이신동 안암교육학회 2010 한국교육학연구 Vol.16 No.2

본 연구는 창의적 문제해결(Creative Problem Solving; CPS)모형을 적용한 미술활동이 영 재와 일반아동의 창의력, 공간능력, 도형유추능력에 미치는 영향을 알아보고, 그 차이를 밝 히는데 있다 연구대상은 K-WISC-Ⅲ 지능검사를 통해 선별된 100명을 실험집단과 비교집단으로 나누었 다. 실험집단(영재아동 25명, 일반아동 25명)은 CPS모형을 적용한 미술활동을 실시하고, 비교집단(영재아동 25명, 일반아동 25명)은 일반미술활동을 적용 하였다. 연구의 결과는 3way ANOVA의 혼합설계로 결과를 분석하였으며 구체적 내용은 다음과 같다. 첫째, 창의 력 요인 중에서 독창성과 성급한 종결에 CPS모형이 긍정적 영향을 미쳤다. 즉 ‘유창성’은 통계상 유의한 차이를 보여 주었지만 실험집단보다 비교집단에서 긍정적 효과가 나타났으 며 그중에서도 일반아동보다 영재아동에게 긍정적 영향을 미쳤다. 둘째, ‘공간능력’은 2․3 차원 회전, 2차원 변환, 3차원 변환’의 세 가지 하위요인에 CPS모형을 적용한 미술활동이 모두 유의미한 긍정적인 영향을 주었다. 셋째, 도형유추능력’에 대해서는 하위요인으로 ‘첨 가․소멸, 변형’의 두 가지 요인 모두에서 CPS모형이 긍정적인 결과를 나타내었다. 본 연 구의 CPS모형을 적용한 미술활동은 각 하위요인 별로 차이를 나타내지만 영재와 일반아동 의 창의력과 공간능력, 도형유추능력에 긍정적 영향이 미치는 것을 알 수 있었다. This paper aims to examine the effects of art activities applying creative problem solving model on creativity, spatial ability, geometric analogy ability of both the gifted children and the average children and to compare the differences. For this research, I have selected one hundred children through the intelligence test of K-WISC-Ⅲ. The experimental group which is composed of twenty five gifted children and twenty five average children performed CPS model based art activities while the comparative group with twenty five gifted children and twenty five average children performed general art activity. The result is analysed by mixed design of 3 way ANOVA and the following is the findings from the analysis. Firstly, in terms of creativity, CPS model showed positive effects for originality and premature closure. While ‘fluency’ displayed statistically significant difference, the comparative group rather than the experimental group showed more positive effect. Moreover the gifted children among the comparative groups showed more positive effect than the average children. Secondly, in terms of ‘spatial ability’, CPS model based art activities resulted in meaningful positive effects, which adopted ‘two․three dimension rotation, two dimension transformation, three dimension transformation’. Thirdly, in terms of ‘geometric analogy ability’, CPS model based art activities showed positive results all in ‘additions․deletions, transformation’ which are subordinate elements of geometric analogy ability. As a result, this research discovered that CPS model based art activities make positive effects for creativity, spatial ability, geometric analogy ability of gifted children and average children will all the different effect in each area.

백화점 3사의 온-오프라인 통합전략 사례연구

최인혁,이영렬 한국유통학회 2003 한국유통학회 학술대회 발표논문집 Vol.- No.-