• Journal of Chest Surgery
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• v.21 no.4
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• pp.630-640
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• 1988

We clinically evaluated 222 cases of ventricular septal defect which we experienced at Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital between July 1981 and March 1988. These patients were occupied 46.2% of all congenital heart disease operated on its same period. Of 222 cases, 132 patients were male and 90 patients were female. Their age distribution ranged from 8 months to 34 years of age and their mean age was 10.3 years. Among these patients, 86 patients had associated cardiac anomalies, which were patent foramen ovale 43 cases[19.5%], Atrial septal defect 18 cases[8.1%], patent ductus arteriosus 8 cases[3.6%], aortic insufficiency 7 cases[3.2%], infundibular pulmonary stenosis 5 cases[2.3%] and etc. There was statistically significant correlationship between VSD size and Qp/Qs, Rp/Rs, Pp/Ps respectively. All cases were operated under cardiopulmonary bypass and 157 patients[70.7%] would be corrected through right atrial approach. 158 patients[71.2%] underwent closure of ventricular septal defect with primary closure and the remained patients[28.8%] with patch closure. In anatomical classification by Kirklin, type I constituted 23.4%, type II 73.4%, type III 0.5%, type I and type II 1.4%, and type II and type III 1.4%. Important postoperative EGG changes were noted in 57 cases[25.7%] and incomplete right bundle branch block was most common[12.6%]. 54 patients[24.3%] developed minor and major postoperative complications and 9 patients died of several complications and overall operative mortality was 4.1%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2145-2152
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• 2013

Paper manufacturing industries have huge facilities with automatic equipments. Especially, in order to improve the efficiency of the paper manufacturing processes, it is necessary to detect the paper cutting defect effectively and to classify the causes correctly. In this paper, we review the problems of web monitoring system and web inspection system that have been traditionally used in industries for defect detection. Then we propose a novel paper cutting defect detection method based on the local binary pattern analysis and its implementation to mitigate the practical problems in industry environment. The proposed algorithm classifies the defects into edge-type and region-type and then it is shown that the proposed system works stably on the real paper cutting defect detection system.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.668-670
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• 1999

We have developed a automatic surface inspection system for cold Rolled strips in steel making process for several years. We have experienced the various kinds of surface inspection systems, including linear CCD camera type and the laser type inspection system which was installed in cold rolled strips production lines. But, we did not satisfied with these inspection systems owing to insufficient detection and classification rate, real time processing performance and limited line speed of real production lines. In order to increase detection and computing power, we have used the Dark Field illumination with Infra_Red LED, Bright Field illumination with Xenon Lamp, Parallel Computing Processor with Area typed CCD camera and full software based image processing technique for the ease up_grading and maintenance. In this paper, we introduced the automatic inspection system and real time image processing technique using the Object Detection, Defect Detection, Classification algorithms. As a result of experiment, under the situation of the high speed processed line(max 1000 meter per minute) defect detection is above 90% for all occurred defects in real line, defect name classification rate is about 80% for most frequently occurred 8 defect, and defect grade classification rate is 84% for name classified defect.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.187-188
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• 2019

The supply of apartments has continuously increased, and the housing supply rate has exceeded 100 percent and the demands and standards of tenants have also been raised as technology has developed. This has led to the conflict and caused social and economic losses. In this study, the case investigation and research methods of the prior research are analyzed as the basis for identifying the defects cases of causes and influences occurring in the apartment building. To analyze various studies, we divided the prior research into the defect management process and the study on the type of defects and countermeasures, and investigated the features and limitations. Future research will be conducted on apartment buildings within 10 years of completion among conglomerate's nationwide apartments to compensate for the limitations of prior research. In addition, AHP static method and relational chart will be used to identify the relationship between the type of defect and the cause and the importance of the influencing factors.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.498-505
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• 2013

The main processes involved in a defect dispute are consulting, reviewing, and finally judging as an arbiter. This process of defect consulting produces a defect consulting report, but business practices and standards of judgment will differ among consultants, and have many problems. This study reviews the structure of a defect consulting report and considers the structure's problem, which is that it is not standardized. To achieve this, data of sixteen defect consulting report were collected involving defect lawsuit cases before or after 2010. The structure and index of the defect consulting reports were then reviewed, and the results are as follows. As for a structure based on fourteen index, there are suitable that judge a outline, a cost estimate data and a consulting work item by a consulting standard. Furthermore, analysis by each common parts and private parts is considered as appropriate about consulting items and estimate by standard. However, consulting item in construction progress and responsibility period for security that related on a cause and a responsibility of defect need to complement. Meanwhile, the first thing of issues are connected a defect consulting is urgent a standardization for a defect type.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.4
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• pp.486-490
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• 2013

A defect which is axially oriented with small size is hard to detect in conventional system. CMFL(Cricumferential Magnetic Flus Leakage) type PIG(Pipelines Inspection Gauge) in the NDT(Nondestructive Testing), is operated to detect this defect called axially oriented cracks in the pipe. It is necessary to decompose the size and shapes of cracks for the manintenance of underground pipelines. This article is focused on the decomposing method of the size and shape of the axially oriented cracks by using inspection signal data for defect.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.70-73
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• 2017

We investigated n-i-p type single junction hydrogenated amorphous silicon oxide solar cells. These cells were without front surface texture or back reflector. Maximum power point efficiency of these cells showed that an optimized device structure is needed to get the best device output. This depends on the thickness and defect density ($N_d$) of the active layer. A typical 10% photovoltaic device conversion efficiency was obtained with a $N_d=8.86{\times}10^{15}cm^{-3}$ defect density and 630 nm active layer thickness. Our investigation suggests a correlation between defect density and active layer thickness to device efficiency. We found that amorphous silicon solar cell efficiency can be improved to well above 10%.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.219-222
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• 2001

Nondestructive nonlinear acoustic method in two dimensions is suggested as a useful tool for detecting defects in a composite layer-structured material. Spectrum level changes in fundamental and harmonic frequencies are observed in the presence of a layer type defect compared with in the absence of such a defect. It is proposed in this study that such spectrum changes we due to the mode conversion. The layer type defect makes different normal modes due to different boundary conditions in the thickness direction for the Lamb waves propagating in a layer-structured material. Specifically, the normal mode with the fundamental frequency in the case of the water-layer gap is converted to the normal mode with the second harmonic frequency in the case of the air-layer gap.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.6
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• pp.7-11
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• 2002

This paper estimates defect and outbreak probabilities of each individual component from some subset of masked data where the exact component causing system failure might be unknown. A system consists of k components that fails whenever there is a defect in at least one of the components. Due to cost and time constraints it is not feasible to learn exactly which components are defective. Because, test procedures ascertain that the defective components belong to some subset of the k components. This phenomenon is termed masking. We describe a, b, c type in which a sample of masked subsets is subjected to intensive failure analysis. This recorded data of a, b, c type enables maximum likelihood estimation of defect probability of each individual component and leads to outbreak of the defective components in future masked failures.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.169-173
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• 1993

In this paper, the features extraction of reflected signals from various type of defects existing in the solid has been studied by Wiener filtering technique. In this experiment, three types of the defect have been considered; a flat cut, a angular cut and a circular hole. All of the defects have the same size, 20mm in diameter and have been located at 45mm in depth from the aluminum surface. In the result of the experiment, it has been found that the wiener filtering technique used for features extraction from the reflected signal corresponding to each defect have been very effective for defect classification.