• 제목/요약/키워드: defect analysis

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냉각재 공급자관 위상배열 검사 적용에 따른 결함 분석 (Analysis of Defect in CANDU Feeder Pipe using Phased Array Ultrasonic Inspection System)

  • 이상훈;진석홍;김인철
    • 한국압력기기공학회 논문집
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    • 제6권1호
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    • pp.78-82
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    • 2010
  • The feeder pipe of Main Primary Heat Transfer System in Wolsong Nuclear Power Plant was inspected by the Ultrasonic Phase Array technique in 2010. It is the first time to apply this method to the construction at Nuclear Power Plant in Korea. The time required for UT technique is less than RT method. The UT method doesn't need to evacuate personnel who works nearby inspecting area and doesn't need to wait developing of film. For these reasons, the UT method is the fastest method among the volumetric inspections. As a result of the examination, it became clear that main defect of the feeder pipe is the Lack of fusion in the welded area. Moreover, the rate of defect was reduced gradually as improvement of welder's skill. If welding machine has problem, the defect has tended to same pattern(occurred same position in the welding area) but these defects were founded without specific rules. For these reasons, the creation of defect is dependent on the skill of worker not on the automatic welding machine. This evaluation of defect signal and collecting data would be useful to further examination in ISI.

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소비자 관점에서 본 주택 및 인테리어 하자 실태 분석 및 인테리어 서비스 평가 (Analysis on Defect Disputes in Housing & Interior Design from Consumers' Perspective and Interior Design Service Evaluation)

  • 이소영;전경민
    • 한국주거학회논문집
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    • 제27권5호
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    • pp.65-72
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    • 2016
  • The purpose of the study was to investigate defect cases in residential interior design, to identify the state of defects, and to categorize types of defect and disputes. In addition, consumer appraisal to residential interior design service were analyzed. The results of this study could provide fundamental information regarding the defects and claims in residential interior design. First, we did literature review for defect disputes in architectural design and interior design. We identify the definition of defects by building life cycle, by state of construction, by activity, and by design performance. Second, we analysed interior design defects cases reported in Korea Consumer Agency & Ministry of Land, Infrastructure and Transport. A total of 49 cases of defect disputes in residential interior design from 2000 to 2015 were investigated. As a result, many defects appeared during the construction stage. A majority of defects cases fall into insulation, water-proofing/leakage work. In terms of design aspects claim, functional and aesthetic defects were claimed. Third, from Consumer Market Evaluation Indicators, raw data from 500 respondents were investigated for the housing repair and interior design. It is found that information comparability, responsiveness to consumer claim, price, and safety are important factors for consumer satisfaction in interior design.

Embedded SW의 품질 측정 프로세스 관리 방법에 관한 연구 (Quality Measurement Process Management Using Defect Data of Embedded SW)

  • 박복남
    • 한국IT서비스학회:학술대회논문집
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    • 한국IT서비스학회 2003년도 추계학술대회
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    • pp.713-721
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    • 2003
  • Embedded 소프트웨어의 품길 측정 프로세스 관리는 Embedded 시스템의 적시성과 품질 만족을 위해서도 필요하다. 그러나, Embedded 소프트웨어의 결함에 대하여 사전 분석하거나 예측 없이 개발 프로세스 상에서 결함을 관리하는 것은 위험이 따른다. 본 연구에서는 Embedded 소프트웨어에서 품질 측정 프로세스 관리를 위해 소프트웨어의 정량적 속성 중에 가장 중요한 요소 중에 하나인 결함을 중심으로 본 연구가 진행되었다. Embedded 소프트웨어에 가장 적합한 프로세스를 정의하고 개선하고자 하는 과정에서, 프로세스 관리를 효과적으로 수행하기 위해 Embedded 소프트웨어의 특성과 결함 특성을 이해하고, 이를 근간으로 결함 속성을 정의하고 결함을 통한 품질 측정 프로세스 관리를 할 수 있도록, 결함 데이터를 이용하여 프로세스를 관리하는데 기여하고자 한다. 따라서, 본 연구에서는 결함 데이터 분석을 위해 필요한 속성을 파악하고, 테스트 단계를 중심으로 결함 데이터의 활용과 결함데이터를 이용한 프로세스 관리 방법을 제안하여, 이를 통해 Embedded 소프트웨어 프로세스를 관리하는 분들에게 효과적인 활용이 될 수 있도록 한다.

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Impact of bonding defect on the tensile response of a composite patch-repaired structure: Effect of the defect position and size

  • N., Kaddouri;K., Madani;S.CH., Djebbar;M., Belhouari;R.D.S.G., Campliho
    • Structural Engineering and Mechanics
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    • 제84권6호
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    • pp.799-811
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    • 2022
  • Adhesive bonding has seen rapid development in recent years, with emphasis to composite patch repairing processes of geometric defects in aeronautical structures. However, its use is still limited given its low resistance to climatic conditions and requirement of specialized labor to avoid fabrication induced defects, such as air bubbles, cracks, and cavities. This work aims to numerically analyze, by the finite element method, the failure behavior of a damaged plate, in the form of a bonding defect, and repaired by an adhesively bonded composite patch. The position and size of the defect were studied. The results of the numerical analysis clearly showed that the position of the defect in the adhesive layer has a large effect on the value of J-Integral. The reduction in the value of J-Integral is also related to the composite stacking sequence which, according to the mechanical properties of the ply, provides better load transfer from the plate to the repair piece through the adhesive. In addition, the increase in the applied load significantly affects the value of the J-Integral at the crack tip in the presence of a bonding defect, even for small dimensions, by reducing the load transfer.

Spontaneous healing capacity of rabbit cranial defects of various sizes

  • Sohn, Joo-Yeon;Park, Jung-Chul;Um, Yoo-Jung;Jung, Ui-Won;Kim, Chang-Sung;Cho, Kyoo-Sung;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제40권4호
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    • pp.180-187
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    • 2010
  • Purpose: This study evaluated the spontaneous healing capacity of surgically produced cranial defects in rabbits with different healing periods in order to determine the critical size defect (CSD) of the rabbit cranium. Methods: Thirty-two New Zealand white rabbits were used in this study. Defects of three sizes (6, 8, and 11 mm) were created in each of 16 randomly selected rabbits, and 15-mm defects were created individually in another 16 rabbits. The defects were analyzed using radiography, histologic analysis, and histometric analysis after the animal was sacrificed at 2, 4, 8, or 12 weeks postoperatively. Four samples were analyzed for each size of defect and each healing period. Results: The radiographic findings indicated that defect filling gradually increased over time and that smaller defects were covered with a greater amount of radiopaque substance. Bony islands were observed at 8 weeks at the center of the defect in both histologic sections and radiographs. Histometrical values show that it was impossible to determine the precise CSD of the rabbit cranium. However, the innate healing capacity that originates from the defect margin was found to be constant regardless of the defect size. Conclusions: The results obtained for the spontaneous healing capacity of rabbit cranial defects over time and the underlying factors may provide useful guidelines for the development of a rabbit cranial model for in vivo investigations of new bone materials.

결함 추적 시스템에 의한 소프트웨어 결함 분석 및 관리기법 연구 (A Study on Software Fault Analysis and Management Method using Defect Tracking System)

  • 문영준;류성열
    • 정보처리학회논문지D
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    • 제15D권3호
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    • pp.321-326
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    • 2008
  • 프로젝트 진행중에 발견하지 못한 결함이 소프트웨어 개발 완료 후 유지보수 단계에서 발견되는 경우가 많이 있다. 유지보수 단계에서 결함의 발생 빈도가 높을수록 비용은 증가하고 품질은 저하되며 고객의 신뢰성을 떨어뜨린다. 결함은 조직에서 발생에 대한 원인 분석 및 프로세스 개선이 지속적으로 이루어지지 않으면 감소하지 않는다. 본 논문에서는 파레토 법칙에 따라 결함은 이미 발생된 유형이 반복되어 전체 결함 유형의 대부분을 차지한다는 점에 감안하여 DTS를 구현하였다. DTS는 유지보수 단계에서 과거에 발생했던 결함 유형의 이력을 바탕으로 결함의 원인을 추적하여 개발자, 운영자 및 유지보수 담당자에게 개선을 위한 근본 데이터를 제공함으로써 같은 유형의 결함이 반복적으로 발생하지 않도록 최대한 지원해 준다. DTS의 기본 활동은 프로그램의 결함유형 분석 및 측정 지표를 제공하고, 프로그램별 결함 유형을 집계한다. 이렇게 측정된 결함의 유형 사례를 해당 업무 팀에서 확인함으로써 지속적으로 결함을 개선할 수 있도록 지원한다. W사의 프로그램 형상관리 시스템에서 DTS를 구현하고 적용한 결과 약 65%정도의 결함이 개선되었다.

Investigation of shinning Spot Defect on Hot-Dip Galvanized Steel Sheets

  • Liu, Yonggang;Cui, Lei
    • Corrosion Science and Technology
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    • 제13권4호
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    • pp.125-129
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    • 2014
  • Shinning spot defects on galvanized steel sheets were studied by optical microscope, scanning electron microscope(SEM), Energy Dispersive Spectrometer (EDS) and Laser-Induced Breakdown Spectroscopy Original Position Statistic Distribution Analysis (LIBSOPA) in this study. The research shows that the coating thickness of shinning spot defects which caused by the substrate defect is much lower than normal area, and when skin passed, the shinning spot defect area can not touch with skin pass roll which result in the surface of shinning spot is flat while normal area is rough. The different coating morphologies have different effects on the reflection of light, which cause the shinning spot defects more brighter than normal area.

이차공형 심방중격결손증의 임상적 고찰 (Clinical analysis of ostium secundum atrial septal defect)

  • 이종태
    • Journal of Chest Surgery
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    • 제17권4호
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    • pp.607-613
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    • 1984
  • Thirty seven patients with ostium secundum atrial septal defect, operated from January, 1976 to September, 1984 at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital, were given clinical assessment. The following results were obtained. 1.Ostium secundum atrial septal defect was comprised of 18% of congenital heart disease. Their mean age was 15.7\ulcorner.42. Sex ratio [male:female] was 1:1.1. 2.Most frequent clinical symptom was dyspnea on exertion occurred in 26 patients [76.5%]. Only one patient had no symptom [2.9%]. 3.Pre-operative EKG findings revealed RVH in 61.8%, ICRBBB in 29.4%, and RAD in 41.2%. 4.Mean value of systolic pulmonary arterial pressure in patients over 20 years old was 37.8\ulcorner4.4mmHg and it was 28.1\ulcorner10.2mmHg in patients under 20 years old, but the difference between two groups was not statistically significant. 5. In large defect group [>3cm in diameter], Qp/Qs was significantly increased than small defect group [<3cm in diameter], but systolic pulmonary arterial pressure and Rp/Rs were not different between two groups. 6. Overall operative mortality was 5.4%.

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Nondestructive Detection of Defect in a Pipe Using Thermography

  • Choi, Hee-Seok;Joung, Ok-Jin;Kim, Young-Han
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1413-1416
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    • 2005
  • An infrared temperature sensor module developed for the detection of defects in a plate was modified to use in a cylinder. A set of optical fiber leads and a mechanism maintaining sensor-object distance constant were utilized for the modification of the IR sensor module. The detection performance was experimentally investigated, and the measured temperature was also compared with computed temperature distribution. The experimental outcome indicates that the detection of a simulated defect is readily available. The temperature distribution is better for defect detection than that with the previous device. In addition, the measured distribution is comparable to the calculated one using a heat conduction equation. The developed device of defect detection is suitable to be utilized in chemical processes where most of vessels and piping systems are in the shape of a cylinder.

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CRT 판넬의 첵 불량 검출을 위한 새로운 조명 시스템 (A New Lighting System for the Inspection of Check Defect of CRT Panel)

  • 차준혁;권인소;하종은
    • 제어로봇시스템학회논문지
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    • 제10권6호
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    • pp.487-493
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    • 2004
  • In this Paper, we propose a lighting system for the stable detection of check defects of the CRT panel through the analysis of the lighting interaction between the lighting unit and the CRT panel. The check defect is very difficult to detect reliably because of its high sensitivity according to the direction of incident light. At first, we model the physical shape of check defects using SEM image. And then we apply physics based illumination model to investigate the optical characteristics of the check defect. Finally, we propose a lighting system for the stable detection of check defect. Experimental results show the feasibility of the proposed lighting system for check inspection.