• 제목/요약/키워드: Point defect

검색결과 492건 처리시간 0.028초

전두골 결손 마우스 모델의 골형성 자동 분석 (Automatic Analysis of Bone Formation in a Mouse Model of Frontal Bone Defect)

  • 강선경;정성태
    • 한국멀티미디어학회논문지
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    • 제18권9호
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    • pp.997-1007
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    • 2015
  • In this paper, we propose a method for automatically analyzing the bone formation in a mouse model of frontal bone defect. We perforate two holes of 0.8mm diameter in the frontal bone and observe the bone formation process using a micro CT. Because the conventional analysis software of the micro CT does not support automatic analysis of the bone formation status, we have to use a manual analysis method. However the manual analysis is very cumbersome and requires a lot of time, we propose an automatic analysis method. It rotates the image around three axes directions so that the mouse's skull come into regular position. It calculates the cumulative image of the voxel values for the perforated bone surface. It estimates the hole location by finding the darkest point in the cumulative image. The proposed method was applied to 24 CT images of saline administration group and PTH administration group and hole location was estimated. BV/TV index was calculated for the estimated hole to evaluate the bone formation status. Experimental results showed that bone formation process is more active in PTH administration group. The method proposed in this paper could replace successfully the cumbersome and time consuming manual job.

CMP 공정에서 슬러리 필터설치에 따른 결함 밀도 개선 (Improvement of Defect Density by Slurry Fitter Installation in the CMP Process)

  • 김철복;서용진;김상용;이우선;김창일;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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    • pp.30-33
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    • 2001
  • Chemical mechanical polishing(CMP) process has been widely used to planarize dielectrics, which can apply to employed in integrated circuits for sub-micron technology. Despite the increased use of CMP process, it is difficult to accomplish the global planarization of free-defects in inter-level dielectrics (ILD). Especially, defects like micro-scratch lead to severe circuit failure, and affects yield. CMP slurries can contain particles exceeding $1{\mu}m$ size, which could cause micro-scratch on the wafer surface. The large particles in these slurries may be caused by particle agglomeration in slurry supply line. To reduce these defects, slurry filtration method has been recommended in oxide CMP. In this work, we have studied the effects of filtration and the defect trend as a function of polished wafer count using various filters in inter-metal dielectric(IMD)-CMP. The filter installation in CMP polisher could reduce defect after IMD-CMP. As a result of micro-scratches formation, it shows that slurry filter plays an important role in determining consumable pad lifetime.

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자동차 제작결함조사 통계 분석을 통한 리콜제도 연구 (A Study on Recall Systems of Motor Vehicle by Statistical Analysis of Defects Investigation)

  • 송지현;권해붕;이광범;김희준
    • 자동차안전학회지
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    • 제7권4호
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    • pp.20-25
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    • 2015
  • The basic point of a vehicle recall is to remove vehicle defects as soon as possible and thus prevent possible road traffic accidents caused by the defects beforehand. Therefore, the core of vehicle recall under the self-certification system consists of a timely response and fast remedy of defects. The present study aimed to deduce a plan for improvement of the system necessary for the fast remedy of defects through a phased analysis of defect investigation procedure based on defect investigation statistical data. There will be a need to make the TSB(Technical Service Bulletin) or service campaign data submission of a manufacturer compulsory for the collection of broad defect information in the stage of information analysis and to impose a higher penalty when the manufacturer violates the data submission in the investigation stage. In addition, it is considered that an active service campaign should be induced and a punishment for late recall will be needed for consumer protection.

원공결함을 갖는 SM45C 인장시험편의 강도해석과 음향방출에 관한 사례연구 (Case Study on the Load-Deflection and Acoustic Emission Analysis of SM45C Coupons with a Circular Hole Defect under Tensile Loading)

  • 우창기;이장규
    • 한국공작기계학회논문집
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    • 제17권1호
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    • pp.50-58
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    • 2008
  • The SM45C metallic coupons have been tested under static tensile loading with acoustic emission (AE) as the load-deflection curve mainly. In this study, we used AE to detect the yielding of material and AE techniques was applied to rapidly estimate the mechanical characteristics of a material. First, coupons without an artificial defect were tested at different cross-head speed. For all cases in this analysis, yielding point of SM45C coupons did not appear definitely compared to mild steel, whereas coupons start to generate AE counts upon yielding. So all cases are normalized to know the possibility of accelerated life test of a material. And next, coupons with different from sizes of circular hole defects were tested at the same cross-head speed of 5 mm/min. Results were classified into 3 classes and analyzed by AE amplitude & signal strength as a function of time. Summarizing the specific conclusions, we need to additional research considering plate with width-ratio in order to estimate the fracture mechanism.

전외측 대퇴부 천공지 유리피판을 이용한 하지 재건 (Reconstruction of Lower Extremities using Anterolateral thigh Perforator Free Flaps)

  • 김태곤;강민구
    • Journal of Trauma and Injury
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    • 제20권2호
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    • pp.119-124
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    • 2007
  • Purpose: Management of the soft tissue defect in the lower extremity caused by trauma has always been difficult. Coverage with local and free muscle flaps after complete surgical excision of necrotic soft tissue and bone is a major strategy for treatment. There is no doubt that muscle provides a good blood supply, thus improving bone healing and increasing resistance to bacterial inoculation. However, accompanying problems are seen in cases with shallow dead space. This research was conducted to assess the efficacy of raising anterolateral thigh flaps and transferring them to the defect after complete debridement of non-viable, infected, and scar tissue as an alternative way to use local or free muscle flaps. Methods: From March 2005 to October 2007, 18 cases of soft tissue defect on lower extremities were re-surfaced with an anterolateral thigh perforator free flap. Results: The follow-up period ranged from 1 to 31 months with a mean of 15.9 months. All flaps survived completely. Satisfactory aesthetic and functional results were achieved. Under a two-point discrimination test, 13 patients had sensory recovery from 11 mm to 20 mm after 6 months postoperatively. Conclusion: Reconstruction of the lower extremity with anterolateral thigh perforator free flaps after appropriate debridement is a good alternative way to use local or free muscle flaps.

표면 마모결함을 고려한 증기발생기 세관의 구조건전성 평가 (Structural Integrity Evaluation of SG Tube with Surface Wear-type Defects)

  • 김종민;허남수;장윤석;황성식;김정수;김영진
    • 대한기계학회논문집A
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    • 제30권12호
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    • pp.1618-1625
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    • 2006
  • During the last two decades, several guidelines have been developed and used for assessing the integrity of a defective steam generator (SG) tube that is generally caused by stress corrosion cracking or wall-thinning phenomenon. However, as some of SG tubes are also failed due to fretting and so on, alternative failure estimation schemes are required for relevant defects. In this paper, parametric three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of SG tubes with different defect configurations; elliptical wear, tapered and flat wear type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of SG tube. After investigating the effect of key parameters such as defect depth, defect length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wear region. Comparison of failure pressures predicted by the proposed estimation scheme with corresponding burst test data showed a good agreement.

유전자 알고리즘을 이용한 항공기용 가스터빈 엔진의 단일 결함 진단에 대한 연구 (A Study on Diagnostics of Single Performance Deterioration of Aircraft Gas-Turbine Engine Using Genetic Algorithms)

  • 김승민;용민철;노태성;최동환
    • 한국항공우주학회지
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    • 제35권3호
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    • pp.238-247
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    • 2007
  • 유전자 알고리즘은 자연선택과 유전법칙을 적용하여 최적해를 탐색하는 방법으로, 본 연구에서 항공기용 가스터빈 엔진의 결함 진단을 위한 학습 알고리즘으로 사용되었다. 성능 저하를 고려한 구성요소는 압축기, 가스발생기 터빈, 동력 터빈이며, 설계점에서 엔진의 단일 구성요소에 대하여 각각 성능 저하 예측을 수행한 후, 이를 바탕으로 결함 진단을 수행하였다. 학습데이터 수의 증가가 유전자 알고리즘을 이용한 성능 저하 예측 및 결함 진단에 미치는 영향을 분석하였으며, 결과적으로 결함치에 대한 RMS 오차율이 모두 3% 이내로 예측됨을 확인하였다.

하안검 전충결손의 재건의 치험례 (RECONSTRUCTION OF LOWER EYELID DEFECT ; REPORT OF A CASE)

  • 오충원;여환호;이철우;양인석;신강수;박정열
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제14권3호
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    • pp.201-206
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    • 1992
  • The eyelids perform many complex functions and are esthetically important, since eye is focal point of face. Tumor extirpation or trauma can lead to full-thickness eyelid defect, which Should be reconstructed as soon as possible There are a number of operation methods for lower lid reconstruction, and among them, Hughes procedure is a time-honored method. Its advantages are good cosmetic result and conjunctival repair by using eyelid structures to rebuild eyelid structures. However, this is a two-staged procedure in which the vision of the affected eye is obstructed during the interval between the operations. We experienced a case of trauma-induced full-thickness lower lid defect extending over one-third of lid length treated by Hughes method. The cosmetic and functional result was good and there was no donor site morbidity, and now we report this case with review of literatures.

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반도성 rutile의 전기적 성질 및 점결함 형태 (Electrical Properties and Point Defect Types of Semiconducting Rutile)

  • 백승봉;김명호
    • 한국재료학회지
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    • 제8권10호
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    • pp.931-937
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    • 1998
  • 순수한 Rutile에서 점결함의 형태와 전기적 특성을 연구하기 위해 $1~10{-23}$atm의 산소분압 범위 및 $700~1300^{\circ}C$의 온도 범위에서 전기전도도를 측정하였다. 전기전도도의 산소분압 의존성($log\sigma/logPo_2$)으로부터 산소분압 및 온도 변화에 따라 다음과 같은 지배적인 결함들을 제안한다. 1) $Ti_nO_{2n-1}$, 2)침입형 Ti 이온 3)2가로 하전된 산소빈자리 4)불순물에 의해 형성된 2가로 하전된 산소빈자리 5) n-p전이 및 p형 전도 또한, 고유범위의 실험결과로부터 계산한 Ti와 Vo의 결함형성 엔탈피는 각각, 10.2eV와 4.92eV였다.

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공동주택 하자예방 및 관리를 위한 품질점검제도의 실효성 제고방안 연구 (Validity Elevation Scheme of Quality Inspection System for Defect Prevention & Management in Apartment Housing Construction)

  • 박근수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.220-221
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    • 2020
  • Strarting with Buyeong Apartment in Dongtan-2 disrict in 2017, collective complaints of residents are frequently occurring due to low quality problem such as improper construction and defects of apartment houses. Because of this, the Ministry of Land and Transport is preparing a comprehensive improvement scheme to improve the quality of Apartment Housing(AH), taking into account the continuing complaints from the residents of AH and the problem raised by the National Assembly. The basic profile of the improvement scheme is induce the tenants and experts to discover and point out defects that are repaired until the date of use inspection or due date. For this purpose, we suggested this defects management system linkaged by the preliminary inspection and quality inspection system for prospective occupants. In this context, this paper aims to suggest an effective likage method between the preliminary inspection of prospective residents and the quality inspection system implemented by local governments as an ordinance.

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