• Archives of Reconstructive Microsurgery
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• 제7권2호
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• pp.157-164
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• 1998

It has been very difficult to managing partial joint defect in any etiologies, especially in children. Unicondylar defect of the tibial condyle in children reconstructed with proximal fibular head with articular cartilage from 1995. Two kinds of transfering methods were used, peroneal artery pedicled ipsilateral fibula head transposition to defective lateral tibial condyle defect that revealed poor prognosis with gradual absorption of transposed fibular epiphysis. Free vascularized fibular head transplantation with microvascular anastomosis underwent in the case with medial condyle defect of tibia which revealed very satisfactory results. Author can conclude with these clinical experiences: 1. Tranposition without epiphyseal vesssels intact is not sufficient in fibular head osteochondral transplantation in reconstruction of tibial condyle defect. That means peroneal arterial vascular pedicle is not enough for transplanted proximal epiphysis maintains its function on articular surface and growth activity in children. 2. The anterior recurrent tibial artery is one of the most important and easy to utilizing vessel in proximal fibular epiphyseal transplantation. 3. Free vascularized fibular head transplantation is hopeful method in reconstruction of the knee joint in the patient with partial joint defect which has no effective solution in conventional methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.317-321
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• 2008

Piping in the Nuclear Power plants (NPP) are mostly consisted of carbon steel pipe. The wall thinning defect is mainly occurred by the affect of the flow accelerated corrosion (FAC) of fluid which flows in carbon steel pipes. This type of defect becomes the cause of damage or destruction of piping. Therefore, it is very important to measure defect which is existed not only on the welding partbut also on the whole field of pipe. Over the years, Infrared thermography (IRT) has been used as a non destructive testing methods of the various kinds of materials. This technique has many merits and applied to the industrial field but has limitation to the materials. Therefore, this method was combined with lock-in technique. So IRT detection resolution has been progressively improved using lock-in technique. In this paper, the quantitative analysis results of the location and the size of wall thinning defect that is artificially processed inside the carbon steel pipe by using IRT are obtained.

• 한국멀티미디어학회논문지
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• 제18권12호
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• pp.1519-1527
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• 2015

TFT-LCD automatic defect inspection system for detecting defects in place of the visual tester does pre-processing, candidate defect pixel detection, and recognition and classification through a blob analysis. An over-detection result of defects acts as an undue burden of blob analysis for recognition and classification. In this paper, we propose defect detection method based on the histogram distribution modeling of TFT-LCD image to minimize over-detection of candidate defective pixels. Primary defect candidate pixels are detected estimating the skewness of the luminance distribution histogram of the background pixels. Based on the detected defect pixels, the defective pixels other than noise pixels are detected using the distribution histogram model of the local area. Experimental results confirm that the proposed method shows an excellent defect detection result on the image containing the various types of defects and the reduction of the degree of over-detection as well.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.275-278
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• 1998

Recently, the clinical applications of the autogenous cancellous bone from the proximal tibial metaphysis show satisfactory results in the repair of maxillofacial bony defect or deformity. The proximal tibia has the potential to yield viable cancellous bone with a minimum of morbidity. The purpose of this study was to investigate the regeneration of a full thickness proximal tibial bone defect with covering or uncovering of cortical bone. The follow-up periods were 4, 8, and 12 weeks. Bone defect of right side was uncovered and left side was covered with cortical bone. In the experimental group (uncovered cortical bone) at 12 weeks, the inside of defect was filled to normal marrow tissue. The cortical bone defect was united of inner, outer callus at 4, 8 weeks in both study group. At 12 weeks, the cortical bone defect was remodeled and invaded by osteoclast (giant cell) in experimental group. In the experimental specimen at 12 weeks, the regenerating tissue of bone defect was not differ from the control group.

• 한국산업정보학회논문지
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• 제19권6호
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• pp.43-51
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• 2014

TFT-LCD 영상은 다양한 특성의 결함을 포함하고 있다. 배경 영역과의 휘도 차이가 커서 육안으로 식별 가능한 결함부터 휘도 차이가 매우 적어서 육안 검출이 어려운 한도성 결함까지 포함한다. 본 논문에서는 휘도 차이를 이용하여 결함 영역에 포함될 확률이 높은 결함 화소부터 순차적으로 단계를 진행하면서 결함 후보 화소를 검출하고, 검출된 후보 화소를 블랍으로 구성하여 블랍의 크기와 주변 영역과의 휘도차이를 이용한 기법을 통해 최종적으로 결함 영역과 잡음을 구분하여 검출하는 알고리즘을 제안한다. 제안한 알고리즘의 타당성을 확인하기 위해 다양한 결함을 포함하는 영상에 대한 실험 결과를 살펴봄으로써 신뢰도 높은 결함 검출 결과를 입증하였다.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.1-6
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• 2020

In this paper, a method for improving the defect classification performance in steel plate surface has been studied, based on DWT(discrete wavelet transform) and SVM(support vector machine). Surface images of the steel plate have low contrast, uneven, and featureless, so that the contrast between defect and defect-free regions is not discriminated. These characteristics make it difficult to extract the feature of the surface defect image. In order to improve the characteristics of these images, a synthetic images based on discrete wavelet transform are modeled. Using the synthetic images, edge-based features are extracted and also geometrical features are computed. SVM was configured in order to classify defect images using extracted features. As results of the experiment, the support vector machine based classifier showed good classification performance of 94.3%. The proposed classifier is expected to contribute to the key element of inspection process in smart factory.

• 전자공학회논문지 IE
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• 제48권2호
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• pp.26-31
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• 2011

본 논문에서는 LCD 제조공정 상에서 발생할 수 있는 결함을 검사하고 분류할 수 있는 적응적인 LCD 표면 결함 검사 시스템을 제안하였다. 즉, 반복되는 LCD 패턴의 주기를 확정한 후에 결함 패턴을 검출하고 검출된 결함 패턴의 특징을 계산하여 결함을 분류하였다. 그리고 결함을 검출하는 과정에서 발생하는 잡음은 모폴로지 연산자를 이용하여 제거하였다. 또한, 검출된 결함 패턴에서 기하학적인 특징과 통계적 특징을 계산한 후 신경회로망 알고리즘을 이용하여 여러 종류의 결함 패턴을 적응적으로 분류하였으며, 실험 결과 92.3%의 결함 검출율 및 94.5%의 결함 분류 및 인식율을 획득함으로써, LCD 결함 검사 시스템의 실질적인 구현 가능성을 제시하였다.

• 한국건축시공학회지
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• 제10권2호
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• pp.115-123
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• 2010

우리 국민의 거주 형태로 아주 큰 비중을 차지하는 공동주택의 하자는 입주민에게 큰 불편과 손실을 초래하고 있다. 그러나 시공사에서 하자정보의 관리에 조금 더 관심을 기울인다면 많은 하자를 사전에 예방할 수 있으리라 판단된다. 이에 본 연구에서는 하자 발생을 방지시키기 위한 개선된 하자정보관리시스템을 도출하려 한다. 먼저 관리시스템의 취약으로 인한 하자사례를 조사하여 개선된 하자정보관리시스템의 필요성을 확인하고, 다음으로 설문조사를 통하여 그 결과로써 현재의 하자정보관리시스템의 문제점과 개선 필요성을 파악 할 수 있었다. 그리하여 하자정보관리시스템의 개선 방안을 도출하였는데 이는 하자 발생의 예방에 도움이 될 것으로 기대된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.108-111
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• 2022

제품의 결함 탐지를 위한 머신 비전 시스템에 딥러닝을 적용하기 위해서는 다양한 결함 사례에 대한 방대한 학습 데이터가 필요하다. 하지만 실제 제조 산업에서는 결함의 종류에 따른 데이터 불균형이 생기기 때문에 결함 사례를 일반화할 수 있을 만큼의 제품 이미지를 수집하기 위해서는 많은 시간이 소요된다. 본 논문에서는 적은 데이터로도 학습이 가능한 샴 신경망을 제품 결함 탐지에 적용하고, 제품 결함 이미지 데이터의 속성을 고려하여 이미지 쌍 구성법과 대조 손실 함수를 수정하였다. AUC-ROC로 샴 신경망의 임베딩 성능을 간접적으로 확인한 결과, 같은 제품끼리만 쌍을 구성하고 결함이 있는 제품 간에는 쌍을 구성하였을 때, 그리고 지수 대조 손실로 학습하였을 때 좋은 임베딩 성능을 보였다.

• Journal of Chest Surgery
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• 제21권6호
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• pp.1117-1123
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• 1988

Prolapse of the aortic valve is the main cause of insufficiency of the aortic valve as a complication of ventricular septal defect. Aortic insufficiency gets worse by the progress of prolapse of aortic valve due to lack of support of the valve and the hemodynamic effect of blood flow through the ventricular septal defect. This produces typical clinical picture, that may be serious and threatening when it is untreated. Type and timing for the surgical treatment of the ventricular septal defect with aortic insufficiency is considered. Among 113 ventricular septal defect, 9 patients of ventricular septal defect with associated aortic insufficiency were experienced from June. 1983 to June 1988 at the Department of Thoracic and Cardiovascular Surgery, Chon-Buk University Hospital. Male was 6 patients and female was 3 patients. Ages were from 7 years to 24years. 5 patients were from 10 to 19 years age. 3 patients were below 10 years age. The ratio of pulmonary blood flow to systemic f low [Qp/Qs] was 1.53 and in pulmonary vascular resistance, normal or slight increase was 7 patients, moderate 1 patient, and severe 1 patient. Ventricular septal defect was subpulmonic in 5 patients and infracristal in 4 patients. Prolapse of right coronary cusp was 7 patients, right and non coronary cusp 1 patient and non coronary cusp 1 patient. Teflon patch closure of ventricular septal defect was undertaken in 3 patients and primary closure in 1 patient. Among the 4 patients of defect closure alone, one patient performed valve replacement 7 months later due to progressive regurgitation and cardiac failure and the result was good. The other 3 patients were good result. Closure of ventricular septal defect and aortic valvuloplasty performed in 4 patients. 2 patients of these required valve replacement for the sudden intractable cardiac failure and died due to low cardiac output. The cause of intractable cardiac failure was tearing of repaired valve at the fixed site. The other 2 patients were good result. Closure of ventricular septal defect and valve replacement performed in 1 patient with good result.