• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.213-221
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• 2022

Defects are the risk factors in the construction process of buildings. They cause damage, delaying the construction duration. They especially cause adverse effects on the top-down construction method. This study analyzed the degree of construction delay induced by each work type, focusing on defects in the top-down method. Then, we derived construction delay induction coefficient from different work types in order by using the severity of construction delay per defect and the occurrence probability of defect; this assessment model measures the impact of defects on construction delay for each work type. Furthermore, by comparing each work type based on the defect frequency and the construction delay induction coefficient, we found work types that need to be administered attentively. We identified that plastering work was easy to overlook, requiring caution in defect management. This study provides an efficient defect management system suitable for the buildings that are built using the top-down construction method.

• 한국자기학회지
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• 제26권1호
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• pp.24-30
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• 2016

지하에 매설된 가스배관에 발생한 결함 유무를 판별하는 방법으로는 자기누설 신호를 탐지하는 비파괴검사 기법이 사용되어져 왔다. 지하 매설된 배관은 높은 가스 운용압력과 습기와 같은 외부환경에 노출되어 있어 금속부식과 같은 결함들이 군집하여 발생한다. 군집 결함들에 의해 발생한 자기누설 신호는 단일결함 신호와 비교하여 왜곡된 형태를 가지며, 왜곡된 결함 신호의 분포는 최종적으로 결함의 형상 추정을 어렵게 한다. 본 논문에서는 30인치 직경의 배관을 기준으로 다중 결함의 배치 형태와 거리를 달리하며 신호 패턴을 분석하고, 인접한 결함의 분리 가능 여부와 신호 보정을 고려한 개선된 결함 판정 알고리즘을 제안하였다.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.171-176
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• 2013

X-ray cross-sectional image-based inspection technique is one of the most useful methods to inspect the brazing joints of heat exchanger. Through X-ray cross-sectional image acquisition, image processing, and defect inspection, the defects of brazing joints can be detected. This paper presents a method to judge the type of detected defects automatically, and to display them three-dimensionally. The defect type is classified as unconnected defect, void, and so on, based on location, size, and shape information of defect. Three-dimensional display which is realized using OpenGL (Open Graphics Library) will be helpful to understand the overall situation including location, size, shape of the defects in a test object.

• Journal of Periodontal and Implant Science
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• 제39권3호
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• pp.321-329
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• 2009

Purpose: The purpose of this study was to evaluate the bone regeneration of particulated hydroxyapatite(HA) and block type of hydroxyapatite graft in rabbit calvarial defects. Methods: An 8 mm calvarial circular defects were created in sixteen young adult New Zealand white male rabbits (weight $3.0{\sim}3.5kg$). Each defects were filled with Bio-Oss, particulated HA and block type HA. Sham surgery control defects were filled with blood clots. The specimens were harvested at 4 weeks and 8 weeks for histologic and histomorphometric evaluation. Results: Histomorphometric analysis demonstrated statistical differences in defect closure, new bone formation, and bone density of the four groups. Block type of HA group showed increased bone formation and bone density at 4 weeks and 8 weeks compared with Bio-Oss group or sham surgery control group(p<0.05). Conclusions: Block type of HA is an effective material for osteoconduction in rabbit calvarial defects, which may acts as a guide in use of these products in human application.

• 정보과학회 논문지
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• 제42권11호
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• pp.1349-1360
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• 2015

소프트웨어 품질을 향상하기 위해서는 소스에 내재된 결함을 효율적, 효과적으로 제거해야 한다. 개발현장에서는 결함 심각도와 결함 제거율로 결함을 제거하고 있다. 결함을 이용하여 품질을 향상하기 위한 연구로는 결함 발생 빈도과 ISO 품질속성을 이용하여 품질을 향상하려는 연구가 있고, 프로젝트 수행 시 결함을 심각도로 관리하여 품질을 향상시키는 연구가 있었다. 하지만, 결함 자체에 집중하여 결함을 유형화하여 결함 유형 간에는 어떤 영향력이 있는지, 그 영향력으로 인하여 어느 결함 유형이 더 중요한 지에 대한 연구는 미흡한 실정이었다. 이에 본 연구에서는 표준단체, 업체, 연구자들의 소프트웨어 결함 유형을 수집, 분류하여 ANP로 모형화하였다. 또한, 구성된 ANP 모형을 이용하여 일반 응용 소프트웨어에 대하여 결함 유형별 중요도 가중치를 산정하였다. 일반 응용 소프트웨어를 개발할 때, 산정된 가중치를 적용하여 결함을 제거한다면, 좀 더 효율적이고 효과적으로 소프트웨어 품질을 향상할 수 있으리라 기대한다.

• International Journal of Precision Engineering and Manufacturing
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• 제7권3호
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• pp.18-23
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• 2006

The formation degree of sustain (ITO pattern) determines the quality of a PDP (Plasma Display Panel). Thus, in the present study, we attempt to detect 100% of the defects that are larger than $30{\mu}m$. Currently, the inspection method in the PDP manufacturing process is dependent upon the naked eye or a microscope in off-line mode. In this study, a prototype inspection system for PDP ITO patterned glass is developed. The developed system, which is based on a line-scan mechanism, obtains information on the defects and sorts the defects by type automatically. The developed inspection system adopts a multi-vision method using slit-beam formation for minimum inspection time and the detection algorithm is embodied in the detection ability. Characteristic defects such as pin holes, substances, and protrusions are extracted using the blob analysis method. Defects such as open, short, spots and others are distinguished by the line type inspection algorithm. It was experimentally verified that the developed inspection system can detect defects with reliability of up to 95% in about 60 seconds for the 42-inch PDP panel.

• 한국표면공학회지
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• 제53권2호
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• pp.80-86
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• 2020

This paper is concerned with type of imperfections present within the anodic oxide films on AA2024 and surface hardness of the anodic film measured after ink-impregnation. The anodic oxide films were formed for 25 min at 40 mA/㎠ and 15±0.5℃ and 300 rpm of magnet stirring rate in 20% sulfuric acid solution. The ink-impregnation allows clear observations of not only the imperfections within the anodic oxide films but also an indentation mark on the oxide film surface made by a pyramidal-diamond penetrator for the hardness measurement. There were observed four different regions in the anodic oxide films on AA2024 and the surface hardness of the anodic oxide films appeared to be crucially dependent on the type of defects, showing 60~100 H_v on the oxide surface region I with large size black defect, 100~140 H_v on the oxide surface region II with large size grey defect, 140~170 H_v on the oxide surface region III with mall size black and/or grey defects and 170~190 H_v on the oxide surface region IV without defects. The pyramidal indentation marks were observed to be distorted in the regions with a large size black and grey defects, while no distortion of the indentation mark was observed in the regions with small size defects and without visible defects.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.269-270
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• 2021

As the era of the Fourth Industrial Revolution arrives and the culture of contact-less was established due to the long-term COVID-19, the construction industry is striving to develop smart home services to expand the scope of information and communications technology (ICT) to provide convenience to residents. However, various defects are occurring in information and communications technology facilities in apartments, and related research is lacking. In this study, case studies and research methods of related prior studies are analyzed as a basis for identifying the types and causes of defects that occur in information and communications technology facilities. To analyze various studies, we divided them into studies on smart home Internet of Things (IoT), information and communications technology construction of apartments, and investigated their features and limitations. Plus, future research will be conducted on apartments within 10 years of completion among apartments completed by domestic construction companies to supplement the limitations of prior research. In addition, we will prepare basic data on defects of ICT construction by analyzing the major causes of defect types through the analysis of defect types and frequency by detailed work type of information and communications technology construction.

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.419-430
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• 2022

Defects in solids play a vital role on thermoelectric properties through the direct impacts of electronic band structure and electron/phonon transports, which can improve the electronic and thermal properties of a given thermoelectric semiconductor. Defects in semiconductors can be divided into four different types depending on their geometric dimensions, and thus understanding the effects on thermoelectric properties of each type is of a vital importance. This paper reviews the recent advances in the various thermoelectric semiconductors through defect engineering focusing on the charge carrier and phonon behaviors. First, we clarify and summarize each type of defects in thermoelectric semiconductors. Then, we review the recent achievements in thermoelectric properties by applying defect engineering when introducing defects into semiconductor lattices. This paper ends with a brief discussion on the challenges and future directions of defect engineering in the thermoelectric field.

• 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.