• Title/Summary/Keyword: defect engineering

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Automatic Diagnosis of Defects in Roller Element Bearings (롤러 베어링에서의 결함의 자동진단)

  • 유정훈;윤종호;김성걸;이장무
    • Journal of KSNVE
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    • v.5 no.3
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    • pp.353-360
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    • 1995
  • A new automatic diagnostic system for predicting multiple defects in rolling element bearings is developed by taking probbability into account. A database is constructed from the frequency characteristics of tested bearings with various types of defects. The proposed algorithms for the automatic diagnosis of bearing defects are shown to be satisfactory through the experiments. This method can be effectively used for quality control of the rolling bearing in plants.

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Epitaxial Self-Assembly of Block Copolymer Thin Film for Nanofabrication

  • Kim, Sang-Ouk
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.293-293
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    • 2006
  • Self-assembled nanostructures of block copolymer thin films have gathered significant attention due to their potential applications as templates for nanofabrication. However the lack of a robust strategy to control the structure formation in thin film geometries has been considered a major obstacle for the practical application. In this presentation 'epitaxial self-assembly' will be introduced as a successful strategy to control the self-assembled nanostructure of block copolymer. Chemically patterned surfaces prepared by advanced lithographic techniques successfully registered nanodomains in block copolymer thin film without any single defect over an arbitrarily large area.

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Recent Achievements in Stem Cell Therapy for Pediatric Gastrointestinal Tract Disease

  • Bae, Sun Hwan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.16 no.1
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    • pp.10-16
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    • 2013
  • The field of stem cell research has been rapidly expanding. Although the clinical usefulness of research remains to be ascertained through human trials, the use of stem cells as a therapeutic option for currently disabling diseases holds fascinating potential. Many pediatric gastrointestinal tract diseases have defect in enterocytes, enteric nervous system cells, smooth muscles, and interstitial cells of Cajal. Various kinds of therapeutic trials using stem cells could be applied to these diseases. This review article focuses on the recent achievements in stem cell applications for pediatric gastrointestinal tract diseases.

Detected Point Clustering Algorithm For Automatic Visual Inspection (자동외관검사를 위한 검출위치 클러스터링 알고리즘)

  • Ryu, Sun Joong
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.3
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    • pp.1-6
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    • 2014
  • Visual defect inspection for electronics parts manufacturing processes is comprised of 2 steps - automatic visual inspection by machine and inspection by human inspectors. It is necessary that spatial points which were detected by the machine should be adequately clustered for subsequent human inspection. This research deals with the spatial clustering algorithm for the purpose of process productivity improvement. Distribution based clustering is newly developed and experimentally confirmed to show better clustering efficiency than existing algorithm - area based clustering.

Properties of Magnetic Resistance Device in Superconductor Materials (자기 저항소자의 특성)

  • Lee, Sang-Heon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.283-284
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    • 2008
  • The magnetic flux is generated by a vortex current which circulates around the vortex with a sense of rotation opposite to that of the diamagnetic screening surface current. When the external magnetic field was applied to the superconductor magnetometer, some regions of the magnetic sensor will be destroyed, especially the weak link regions and the defect regions. The destroyed regions will be increased with the increasing of the magnetic flux.

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A Study on the Monitoring of Reject Rate in High Yield Process

  • Nam, Ho-Soo
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.773-782
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    • 2007
  • The statistical process control charts are very extensively used for monitoring of process mean, deviation, defect rate or reject rate. In this paper we consider a control chart to monitor the process reject rate in the high yield process, which is based on the observed cumulative probability of the number of items inspected until r defective items are observed. We first propose selection of the optimal value of r in the CPC-r charts, and also consider the usefulness of the chart in high yield process such as semiconductor or TFT-LCD manufacturing process.

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A Study on Defect Prevention for Process Improvement based on CMMI (CMMI기반 프로세스 개선을 통한 장애 예방 연구)

  • Bae, Jang-Jun;Park, Seung-Hyun
    • Annual Conference of KIPS
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    • 2006.11a
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    • pp.527-530
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    • 2006
  • 오늘날 많은 기업들이 납기 단축, 비용 절감 및 효율적인 프로세스 관리 등을 위해 소프트웨어 프로세스 모델 및 표준을 도입하고 있다. 이러한 표준들은 유지보수 과정에서 빈번하게 발생하는 장애를 혁신적으로 감소시켜 안정적 서비스 제공을 한다. 본 논문에서는 CMMI에서 요구되는 프로세스를 좀 더 자세히 체계화하여 CMMI 인증을 받은 금융회사의 장애분석을 통하여 장애의 원인들을 파악하고 이에 대한 개선된 프로세스를 제안하고자 한다.

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UNCERTAINTY ANALYSIS OF DATA-BASED MODELS FOR ESTIMATING COLLAPSE MOMENTS OF WALL-THINNED PIPE BENDS AND ELBOWS

  • Kim, Dong-Su;Kim, Ju-Hyun;Na, Man-Gyun;Kim, Jin-Weon
    • Nuclear Engineering and Technology
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    • v.44 no.3
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    • pp.323-330
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    • 2012
  • The development of data-based models requires uncertainty analysis to explain the accuracy of their predictions. In this paper, an uncertainty analysis of the support vector regression (SVR) model, which is a data-based model, was performed because previous research showed that the SVR method accurately estimates the collapse moments of wall-thinned pipe bends and elbows. The uncertainty analysis method used in this study was an analytic uncertainty analysis method, and estimates with a 95% confidence interval were obtained for 370 test data points. From the results, the prediction interval (PI) was very narrow, which means that the predicted values are quite accurate. Therefore, the proposed SVR method can be used effectively to assess and validate the integrity of the wall-thinned pipe bends and elbows.

Efficient Pre-Bond Testing of TSV Defects Based on IEEE std. 1500 Wrapper Cells

  • Jung, Jihun;Ansari, Muhammad Adil;Kim, Dooyoung;Park, Sungju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.226-235
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    • 2016
  • The yield of 3D stacked IC manufacturing improves with the pre-bond integrity testing of through silicon vias (TSVs). In this paper, an efficient pre-bond test method is presented based on IEEE std. 1500, which can precisely diagnose any happening of TSV defects. The IEEE std. 1500 wrapper cells are augmented for the proposed method. The pre-bond TSV test can be performed by adjusting the driving strength of TSV drivers and the test clock frequency. The experimental results show the advantages of the proposed approach.

A Study on about Implementation to Induction Cooker that load Turbo Inverter algorithm

  • Lee Min-Ki;Koh Kang-Hoon;Kwon Soon-Kurl;Lee Hyun-Woo;nakaoka M.
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.136-139
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    • 2001
  • The voltage resonating inverter has a defect in the switching element that works at 5 or 6 times higher than input voltage. Especially, it is very difficult to choose very high switching device for the 220[V]commercial voltage. In this paper, it is proposed the optimum method to realize the turbo 2000[W] power for induction cooker that is employed the 900[V] IGBT with decreasing operating voltage of the switching component by making the 220[V], 1500[W] inverter through the clamp mode voltage resonating inverter.

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