• 제목/요약/키워드: Multiple Defects

검색결과 309건 처리시간 0.025초

신경회로망을 이용한 원공 결함 패턴 인식에 관한 연구 (A Study on the Pattern Recognition of Hole Defect using Neural Networks)

  • 이동우;홍순혁;조석수;주원식
    • 한국정밀공학회지
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    • 제20권2호
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    • pp.146-153
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    • 2003
  • Ultrasonic inspection of defects has been focused on the existence of defect in structural material and need has much time and expenses in inspecting all the coordinates (x, y) on material surface. Neural networks can have an application to coordinates (x, y) of defects by multi-point inspection method. Ultrasonic inspection modeling is optimized by neural networks Neural networks has trained training example of absolute and relative coordinate of defects, and defect pattern. This method can predict coordinates (x, y) of defects within engineering estimated mean error $\psi$.

Vascularized Bone Graft Reconstruction for Upper Extremity Defects: A Review

  • Ava G. Chappell;Matthew D. Ramsey;Parinaz J. Dabestani;Jason H. Ko
    • Archives of Plastic Surgery
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    • 제50권1호
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    • pp.82-95
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    • 2023
  • Upper extremity reconstruction may pose clinical challenges for surgeons due to the often-critical, complex functional demands of the damaged and/or missing structures. The advent of vascularized bone grafts (VBGs) has aided in reconstruction of upper extremity (UE) defects due to their superior regenerative properties compared with nonvascularized bone grafts, ability to reconstruct large bony defects, and multiple donor site options. VBGs may be pedicled or free transfers and have the potential for composite tissue transfers when bone and soft tissue are needed. This article provides a comprehensive up-to-date review of VBGs, the commonly reported donor sites, and their indications for the treatment of specific UE defects.

개와 사람의 선천성 심장 전도장애에 대한 분자 유전학적 이해 (Molecular Genetics of Inherited Cardiac Conduction Defects in Humans and Dogs)

  • Hyun, Changbaig
    • 한국임상수의학회지
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    • 제21권2호
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    • pp.219-228
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    • 2004
  • 심장 전도계에 관련된 심장 질환은 심장 전도계의 원발성 결함이나 형태학적 심장 질환 및 약물 중독 같은 속발성 원인에 의해 발생한다. 특히 선천성 심장 전도 장애의 경우, 이온 채널, 이온 채널에 관련한 세포질성 단백질, gap-junction 단백질, transcription factors (심장 발생에 관련된 유전자들) 및 kinase subunit을 전사하는 유전자의 돌연변이가 원발성 선천성 심장 전도장애의 원인으로 밝혀지고 있다. 사람의 부정맥 발생에 관련된 발병기전에 커다란 진보가 이루어지고 있음에도 불구하고, 개의 경우, 저먼 세퍼드의 급사 증후군 (sudden death syndrome)을 제외한 다른 전도 장애에 대한 연구는 극히 미비한 상태이다. 본 종설에서는 지금까지 밝혀진 심장 부정맥 발생의 분자 유전학적 고찰과 이와 관련된 사람의 유전학적 질환들과 이와 유사한 개의 선천성 심장 전도 장애에 대해 연구 고찰하였다.

배열와전류프로브를 이용한 증기발생기 세관의 결함 변화에 따른 유한요소해석 (Finite Element Method Analysis of Eddy Current Array Probe According to Defects Variation of Steam Generator)

  • 김지호;이향범
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.54-58
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    • 2009
  • In this paper, the ECT(eddy current testing) signal analysis of eddy current array probe for inspection of SG(steam generator) tube in NPP(nuclear power plant) using electromagnetic FEM(finite element method) was performed. To obtain the electromagnetic characteristics of probes, the governing equation was derived from Maxwell's equation, and the problem was solved by using the 3-dimensional FEM. The types of defects were FBH(flat bottomed hole) and OD groove, Spiral groove, natural defects(pitting, SCC, multiple SCC, wear). The depth of FBH defects were 20%, 40%, 60%, 80%, 100 of SG tube thickness, and it was assumed that the defects were located on the tube outside. And the operation frequency of 100kHz, 300kHz and 400kHz were used. Material of specimen was Inconel 600 which is usually used for SG tubes in NPP. The signal difference could be observed according to the variation of size and depth on FBH defects and operation frequencies. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed.

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Optimization in Multiple Response Model with Modified Desirability Function

  • Cho, Young-Hun;Park, Sung-Hyun
    • International Journal of Quality Innovation
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    • 제7권3호
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    • pp.46-57
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    • 2006
  • The desirability function approach to multiple response optimization is a useful technique for the analysis of experiments in which several responses are optimized simultaneously. But the existing methods have some defects, and have to be modified to some extent. This paper proposes a new method to combine the individual desirabilities.

근육형 심실중격 결손증 (치험 2예) (Muscular Ventricular Septal Defect: Report of 2 cases)

  • 임승평
    • Journal of Chest Surgery
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    • 제12권2호
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    • pp.113-118
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    • 1979
  • The muscular variety of congenital ventricular septal defect [Type IV VSD] comprises from 2 to 18% of the total number of patients and has multiple defects. It is difficult to diagnose by usual angiographic study. Out of 116 cases of isolated ventricular septal defects repaired at this hospital in 20 years period from 1959 and to May 8, 1979, 2 cases had muscular defect which was treated through vertical right ventriculotomy without any problems. Single defect was found in both cases and in one case PDA was associated with Type IV VSD.

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New Retention System Using Branched Polymer

  • Son, Dong-Jin;Kim, Bong-Yong
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.251-256
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    • 2006
  • The purpose of this study was to confirm multiple retention system of C-PAM, A-PAM and Inorganic micro particles vs. traditional micro particle system and dual polymer system by measuring retention, drainage and formation using RDA HSF and Techpap 2D -F Sensor The benefits of dual polymer system were easy to use, low chemical consumption and good retention property but defect was worse drainage property than inorganic microparticle systems. On the other hand, Inorganic microparticle system had benefit of good drainage effect but defects were difficult to use, high chemical consumption. Therefore, we tried to find optimal morphology of polyacrylamide and applied to multiple retention system of C-PAM, A-PAM and inorganic microparticles to compensate defects of both of retention systems. As a result, we found the performance of branched C-PAM, branched A-PAM and inorganic micro particle triple system was more appropriate than traditional inorganic mircoparticle systems or dual polymer systems by comparing retention, drainage and formation.

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도시철도차량 결함평가를 위한 비파괴검사 기법의 적용방안 (A Study on Utilization of Nondestructive Inspection Method for Defects Evaluation in Electric Multiple Units)

  • 편장식;정종덕
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.673-679
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    • 2009
  • Nondestructive inspection(NDI) is a testing procedure used to easily inspect an object for internal defects, abnormalities, shape, and structure, etc. without destroying it. Typical candidates for NDI include buildings, railways, aircraft, bridges, underground pipelines and various types of factory equipment. Recent advances in nondestructive evaluation(NDE) technologies have led to improved methods for quality control and in-service inspection, and the development of new options for material diagnostics. This paper introduces the methods of a survey and assessment on NDI applications in Electric Multiple Units(EMU). The main objective of this paper was to obtain information on various applications of NDI technology in EMU.

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