• Journal of Chest Surgery
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• 제25권3호
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• pp.289-295
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• 1992

We evaluated the correlationship between the predicted defect size at preoperative examination and the actual defect size at operation room, by examining 69 cases of ventricular septal defect operated at the deparment of Thoracic and Cardiovascular surgery, Kyungpook University Hospital from January 1988 to December 1990. We excluded cases associated with other cardiac anomalies. Of the 69 cases, 39 are male and 30 female, forming 1.3:1 sex ratio in males favor. Their age range from 6 months to 16 year, and 4.3 on the average Their body weights are from 6 to 45kg and 15 on the average. According to Soto`s classification, perimembranous type costitutes 42 cases[61%], doubly committed subarterial type 23 cases[33%], and muscular type 4 cases[6%]. The average diameter of defect size is 8.0$\pm$3.5mm measured in 2D-echocardiogram, 5.6$\pm$3.4mm in angiogram, and 7.4$\pm$4.4mm in operative field. There is statistically significant correlation between the size from 2D-echocardiogram and actual defect size[p=0.001], and no significant difference between the two. Especially in the cases without anurysmal formation, they are nearly the same. Cardiothoracic ratio, pulmonary to systemic flow ratio, pressure ratio and resistance ratio also have statistically significant correlation. Main pumonary artery to descending aorta diameter ratio is correlated with the actual defect size. There is statistically significant correlation between the size from angiogram and actual defect size with some difference.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.365-370
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• 1997

In this paper we suggest a development of surface defect inspection algorithms for cold mill strip using tree structure. The defects which exist in a surface of cold mill strip have a scattering or singular distribution. This paper consists of preprocessing, feature extraction and defect classification. By preprocessing, the binarized defect image is achieved. In this procedure, Top-hit transform, adaptive thresholding, thinning and noise rejection are used. Especially, Top-hit transform using local min/max operation diminishes the effect of bad lighting. In feature extraction, geometric, moment, co-occurrence matrix, histogram-ratio features are calculated. The histogram-ratio feature is taken from the gray-level image. For the defect classification, we suggest a tree structure of which nodes are multilayer neural network clasifiers. The proposed algorithm reduced error rate comparing to one stage structure.

• Smart Structures and Systems
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• 제23권1호
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• pp.71-79
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• 2019

In general, it may be advantageous to measure the pressure pulsation near a valve to detect a valve defect in a linear compressor. However, the acceleration signals are more advantageous for rapid classification in a mass-production line. This paper deals with the performance improvement of fault classification using only the compressor-shell acceleration signal based on the relation between the refrigerant pressure pulsation and the shell acceleration of the compressor. A transfer function was estimated experimentally to take into account the signal noise ratio between the pressure pulsation of the refrigerant in the suction pipe and the shell acceleration. The shell acceleration signal of the compressor was modified using this transfer function to improve the defect classification performance. The defect classification of the modified signal was evaluated in the acceleration signal in the frequency domain using Fisher's discriminant ratio (FDR). The defect classification method was validated by experimental data. By using the method presented, the classification of valve defects can be performed rapidly and efficiently during mass production.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.637-640
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• 1999

In this Paper we show the LCD simulator for defect inspection using image processing algorithm and neural network. The defect inspection algorithm of the LCD consists of preprocessing, feature extraction and defect classification. Preprocess removes noise from LCD image, using morphology operator and neural network is used for the defect classification. Sample images with scratch, pinhole, and spot from real LCD color filter image are used. The proposed algorithms show that defect detected and classified in the ratio of 92.3% and 94.6 respectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.91-93
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• 2009

A large steel ingot needs to be larger and larger in size and an ultra high clean, no defect in quality with a low hot top ratio for the resent heavy industry. The demands are very difficult to achieve simultaneously because of their contradictive effect to each other in results. In this study, 30ton steel ingot was cast in a foundry with an optimized design parameter of cast mold and cast process conditions for the low hot top ratio, 12%. The cast ingot was analyzed in macro defect, segregations, and cleanness. No macro defect was founded in central surface of the ingot. The degree of segregation and cleanness are in the controlled range with a sound quality.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.48-49
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• 2019

The number of disputes over defects after completion of construction work in apartment buildings is increasing every year. In this situation, the prediction of reasonable defect repair costs is very important. In this paper, we are going to collect basic data for predicting defect repair costs through the correlation analysis of the construction period and defect repair cost of apartment houses. For this purpose, first of all, the construction period and defect repair cost of apartment houses were analyzed to analyze the construction period for each type of work, the construction period for each project type, and the construction period for each standard calculation. Next, the correlation between defect repair cost and the independent variables of the candidate was conducted. According to the analysis, the ratio of framing air, the ratio of finishing air, and the number of delay days showed strong correlation.

• 한국컴퓨터정보학회논문지
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• 제23권9호
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• pp.81-86
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• 2018

Software defect severity is very important in projects with limited historical data or new projects. But general software defect prediction is very difficult to collect the label information of the training set and cross-project defect prediction must have a lot of data. In this paper, an unclassified data set with defect severity is clustered according to the distribution ratio. And defect severity-based prediction model is proposed by way of labeling. Proposed model is applied CLAMI in JM1, PC4 with the least ambiguity of defect severity-based NASA dataset. And it is evaluated the value of ACC compared to original data. In this study experiment result, proposed model is improved JM1 0.15 (15%), PC4 0.12(12%) than existing defect severity-based prediction models.

• Journal of Chest Surgery
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• 제11권1호
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• pp.46-57
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• 1978

Ventricular septal defect was the most common congenital Heart disease admitted to the Severance Hospital from December, 1963 to June 30. 1977. A total of 1,811 cardiac patients received cardiac catheterization in the CardiacCenter of Yonsei University Medical College. Out of the 1,811 cardiac patients, 791 cases had congenital heart disease and of these 172 cases had ventricular septal defect. This amounted to 21.7% of all those with congenital heart disease. Seventy cases of ventricular septal defect operated on in the chest surgery department are presented. Of these 70 cases of ventricular septal defect, 54 cases were male and 16 cases were female. Their ages ranged from 4/12 months to 32 years. The ratio of systolic pressure of the main pulmonary to systemic artery [Pp/Ps] for 29 of the 59 isolated ventricular septal defects was below 45 percent. Pp/Ps ratio for 19 of the 59 isolated ventricular septal defects was 75 percent. The patients were mostly below fifteen years of age. Out of 64 cases, there were 36 cases of type II defects, 20 cases of type I, 4 cases of type III , 2 cases of type IV, one case of both type II and one case of left ventricular right atrial communication. The anomalies associated with ventricular septal defect were 13 in all; 4 cases of aortic insufficiency, 3 cases of ruptured aneurysm of the sortie sinus of valsalva, 2 cases of ruptured aneurysm of the sortie sinus of valsalva with aortic insufficiency, 2 cases of patent ductus arteriosus, one case of ruptured aneurysm of the aortic sinus of valsalva with atrial septal defect [secundum type] and one case of atrial septal defect [secundum type]. Overall mortality was 8.6 percent. The mortality in pulmonary artery banding was 37.5 percent. The causes of mortality were in one case congestive heart failure, in one case asphyxia and in one case respiratory insufficiency. Tile mortality in ventricular septal defect associated with pulmonary hypertension was 7.1 percent. The cause of mortality was in one case low cardiac output syndrome. There was no mortality in the ventricular septal defects without pulmonary hypertension and mortality in the ventricular septal defect. In ventricular septal defect associated with combined anomalies, the causes mortality were in one case respiratory insufficiency and in one case congestive heart failure.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.190-194
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• 2010

목 적 : 애성 및 음성 변동은 심장병 환자에서 관찰될 수 있는데 이러한 음성 변동 정도를 음향학적 지표의 평가로 분석하여, 소아에서 선천성 심장병 종류에 따른 음성 변동을 음향학적 요소로 분석하고자 하였다. 방 법 : 수술 전 선천성 심장병 환아 94명을 연구 대상으로 하였고 심실 중격 결손, 동맥관 개존, 심방 중격 결손, 폐동맥 협착, 활로 사징이 포함되었으며, 음성 변동을 조사하기 위한 음향 지표 분석은 통증 자극을 통하여 얻어진 음성 자료를 multi-dimensional voice program system을 이용하여 평가하였다. 연구에 사용된 음향 지표로 average fundamental frequency, length of analyzed sample, jitter percent, shimmer, noise to harmonic ratio를 분석하였다. 결 과 : 음향 지표인 average fundamental frequency은 동맥관 개존, 심실 중격 결손, 활로 사징 경우에서 유의한 감소를 나타냈으며, length of analyzed sample은 연구 대상 선천성 심장병 환아에서 대조군에 비해 의미있는 차이를 나타내지 않았다. Jitter percent, shimmer, noise to harmonic ratio는 심실 중격 결손, 동맥관 개존, 심방 중격 결손에서 대조군에 비해 증가되었다. 이러한 음성 변동은 연구 대상 선천성 심장병 중 동맥관 개존에서 음도변이, 강도변이, 음성의 소음 정도가 가장 뚜렷하게 나타났으며, 동맥관 개존, 심실 중격 결손, 심방 중격 결손 순으로 그 음성 변동의 특징을 나타냈다. 결 론 : 수술 전 선천성 심장병 환아에서 음성을 음향학적 지표로 비교 분석한 결과 음향학적 지표들이 심장 질환의 유형별 차이를 보이는데 좌우 단락 심질환군에서 현저한 비정상적 음향학적 지표를 나타냈다.

• 한국해양공학회지
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• 제1권2호
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• pp.74-82
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• 1987

This study has been made to investigate into the behavior of fatigue limit, of fatigue crack initiation, and of fatigue crack propagation under the condition of rotating bending stress; specifically on the independency of stress field as well as the crack behavior of surface micro hole defect, which is made artificially through the specimen. The results obtained can be summarized as followa; 1) For the single micro hole defect, initiation of fatigue crack is occurred at both tips of microhole defect simultaneosly along the slip which are produced in the range of maximum principal stress arround micro hole defect independent of the size of micro hole defect. 2) For the neighbored deuble micro hole defects with equal size, in the range ($\frac{L}{r}$)ratio $\gtrsim$ 3 defined as the size of micro hole defect(2r) to the distance between the centers of micro hole defects (2L), the crack behavior of the micro hole defects is same as single one. However, for the range of $\frac{L}{r}$<3, the interference effect becomes significant as the ratio approaches to 1.