• 제목/요약/키워드: Defects

검색결과 8,536건 처리시간 0.035초

전기적 회로에 의한 색각이상 mechanism 해석 (The Analysis of Color Vision Defects Mechanism for the Electric Circuits)

  • 박상안;김용근
    • 한국안광학회지
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    • 제6권1호
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    • pp.81-85
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    • 2001
  • 색각은 광 수용체인 3개 R. G. B cone의 파장흡수와 대립과정의 r-g, y-b 채널에 의해 이루어진다. 전기적 회로에 의한 색각 이상 mechanism은 photo cell, relay switch, transformer로 구성하였다. 추체(cone)의 R 또는 G가 결손 된 경우 y-b chromic valence 함수가 되고, 추체의 B가 결손 된 경우는 r-g chromic valence 함수가 되어 색각 이상 mechanism을 잘 적용된다.

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CT를 이용한 알루미늄 반응고 성형품의 미세 결함 측정 (Measurements of Micro-Defects in the Aluminum Thixoformed Part using Computed Tomography(CT) Technology)

  • 이상용;김찬현
    • 소성∙가공
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    • 제18권5호
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    • pp.422-427
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    • 2009
  • Computed tomography(CT) has been applied to measure micro-defects in the aluminum knuckle parts manufactured by the thixoforming process. 6061 aluminum alloys were used to form knuckle samples in the semi-solid temperature after the SIMA processing of billets. Tensile specimens were cut from the different locations in a thixoformed knuckle. The size and the distribution of forming defects in tensile specimens were analyzed using CT scanning and image analysis technology before tensile tests. It has been qualitatively shown that the stress-strain curves were significantly affected by the size and the distribution of forming defects although the defect sizes lie in the range of micro-meters.

방실중격결손증의 외과적 치료 (Surgical Treatment of Atrioventricular Septal Defect)

  • 이광숙
    • Journal of Chest Surgery
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    • 제22권6호
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    • pp.990-995
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    • 1989
  • Since 1984, 24 patients underwent repair of atrioventricular septal defect. Nineteen had a partial defect and 5 had a complete atrioventricular septal defect. There were 9 men and 15 women, ranging in age from 1 to 50 years [mean age, 13.3 years]. Four patients had a Downs syndrome. Additional congenital heart defects were present in 11 patients. One patient had palliative operation prior to total correction. In partial defects, the primum atrial septal defect was closed with Xenomedica patch and the mitral valve was repaired with simple closure of the septal commissure. Central incompetence from annular dilatation was repaired by a local annuloplasty. In complete defect, the septal defects were closed with two patches except one. Operative mortality was 5% in partial defects and 60% in complete defects and low cardiac output was the commonest etiology. In a mean follow-up period of 27.9 months [range, 4 to 63 months] there were no late death and no instances of late-onset complete heart block. One patient required reoperation [MVR] for residual mitral regurgitation. The majority of patients were asymptomatic and mean postop. NYHA functional class was 1.2.

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광선추적법을 이용한 비파괴 내부 결함 모델 및 해석 (Modeling and Analysis of a Ray Tracing Method for Non-Destructive Testing for Internal Defects)

  • 김택구;김주한
    • 한국정밀공학회지
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    • 제32권1호
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    • pp.75-81
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    • 2015
  • Modeling and analysis using a ray tracing method for internal defects were described. Reflection and refraction of rays on the interface of defects were modeled using the Harvey model and the Lambertian model. The diffraction on the interface of defects affected the incoming signals and it could evaluate any defects in the matter and its signal would be analyzed with the ray tracing simulation. The simulation results were compared with actual detecting signals and the ray tracing model was shown in good agreement with experimental data. This method has a possibility to be used as wave propagation modeling in non-destructive testing.

건설공사의 성능계약 도입방안에 관한 연구 (A study on the Application Scheme of the Warranty contract in constructions)

  • 김대길;정호근;서용칠;이상범
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.89-92
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    • 2007
  • Since 1960s, advanced constructions have introduced warranty contract which is warranted to quality and performance for need of owner in determined term to ensure the quality of construction. However, the interior of a country encounter another problem result from Defects Liability what indefiniteness of defects standard, excess responsibility period, social recognition of be identical fraudulent work and defects, and contract with ascendancy of owners. etc, so builders concerned more excess defects liability than the quality of construction. The purpose of this study is to analysis of warranty contract in order to solve the problem such as stated above.

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고체절연 시스템에서 부분방전의 통계적 분포를 이용한 결함의 인식 (Defect Recognition with Statistical Distributions of PD in Solid Insulation)

  • 박정남;김진표;박영국;장동욱;임기조
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1930-1932
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    • 2000
  • PD in defects of solid insulation system is very harmful since it leads to deteriorate insulation system by. the discharge electrons and ions bombarding the insulation surface and the action of chemical products that are formed by discharges. PD is used to detect and recognize defects and degradation of insulation system However, there are still marked difficulties to recognize defects by PD methode. In this paper, we investigated properties of PD of defects in solid insulation by using statical methods and classified PD patterns of surface discharge, electrical tree and void discharge with source of discharge, we used specific distributions such as $H_n(q)$, $H_{an}(\phi)$, $H_n(\phi)$, $H_a(\phi)$ to recognize defects of solid insulation system.

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음향 인텐시티를 이용한 결함이 있는 베어링의 특성에 관한 실험적 연구 (An Experimental Study on the Characteristic of Bearings with a Defect using the Sound-Intensity Technique)

  • 이해철;김명균;안기순;차경옥
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 춘계학술대회 논문집
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    • pp.222-228
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    • 1999
  • The two-microphone sound-intensity technique has been used for the detection of defects in radially loaded ball bearings. The difference in the sound-intensity levels measured for bearings with no defect and for those with intentionally introduced defects of different sizes in their elements under various operating conditions of loads and speeds is demonstrated. A change in the intensity frequency spectrum because of the defects is observed. The results show that the detectability of an outer-race defect is much better than that of on inner-race or ball defect. It is difficult to detect defects at lower speeds. Sound-pressure measurements were also performed fur comparison, and it is shown that the detectability of defects by sound-intensity measurements is better than that by sound-pressure measurements.

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트리구조 신경망을 이용한 냉연 강판 표면 결함의 분류 (Classification of Surface Defects on Cold Rolled Strip by Tree-Structured Neural Networks)

  • 문창인;최세호;김기범;주원종
    • 대한기계학회논문집A
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    • 제31권6호
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    • pp.651-658
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    • 2007
  • A new tree-structured neural network classifier is proposed for the automatic real-time inspection of cold-rolled steel strip surface defects. The defects are classified into 3 groups such as area type, disk type, area & line type in the first stage of the tree-structured neural network. The defects are classified in more detail into 11 major defect types which are considered as serious defects in the second stage of neural network. The tree-structured neural network classifier consists of 4 different neural networks and optimum features are selected for each neural network classifier by using SFFS algorithm and correlation test. The developed classifier demonstrates very plausible result which is compatible with commercial products having high world-wide market shares.

QFN 패키지의 Resin Bleed와 Melting 검출 알고리즘 (Algorithm for Segmenting Resin Bleed and Melting on the Surface of QFN Packages)

  • 왕명걸;박덕천;주효남;김준식
    • 제어로봇시스템학회논문지
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    • 제15권9호
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    • pp.899-905
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    • 2009
  • There are many different types of surface defects on semiconductor Integrated Chips (IC's) caused by various factors during manufacturing process, such as Scratch, Flash, Resin bleed, and Melting. These defects must be detected and classified by an inspection system for productivity improvement and effective process control. Among defects, in particular, Resin bleed and Melting are the most difficult ones to classify accurately. The brightness value and the shape of Resin bleed and Melting defects are so similar that normally it is difficult to classify the Resin bleed and Melting. In this paper, we propose a segmenting method and a set of features for detecting and classifying the Resin bleed and Melting defects.

Defect formation mechanism of 6H-SiC crystals grown by sublimation method

  • Kim, Hwa-Mok;Kyung Joo;Auh, Keun-Ho
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1998년도 PROCEEDINGS OF THE 15TH KACG TECHNICAL MEETING-PACIFIC RIM 3 SATELLITE SYMPOSIUM SESSION 4, HOTEL HYUNDAI, KYONGJU, SEPTEMBER 20-23, 1998
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    • pp.35-40
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    • 1998
  • There have two kinds of defects, planar defects and vertical defects which were called micropipes in SiC bulk crystals grown by a sublimation method. We could decrease these defects by adding a little piece of Si in the SiC powder or using Ta cylinder in the crucible. so were report the dependence of these defects in a wafer on silicon/carbon ratio in this paper. The chemical species sublimed from SiC powder is affected by carbon from the graphite wall of the crucible. It is important to control the chemical species on the substrate.

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