• Title/Summary/Keyword: Defect structure

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Defect Structure, Nonstoichiometry and Nonstoichiometry Relaxation of Complex Oxides

  • Yoo, Han-Ill
    • Journal of the Korean Ceramic Society
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    • v.44 no.12
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    • pp.660-682
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    • 2007
  • An SOFC consists of all ceramic complex oxides each with different electrochemical-property requirements. These requirements, in principle, can be made met to a great extent by controlling or tailoring the defect structure of the oxide. This paper reviews the defect structure, nonstoichiometry as a measure of the total defect concentration, and the defect relaxation kinetics of complex oxides that are currently involved in a variety of growing applications today.

Analysis of Consulting Reports on Defect Disputes in Apartment Building

  • Seo, Deok-Seok;Park, Jun-Mo
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.5
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    • pp.498-505
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    • 2013
  • The main processes involved in a defect dispute are consulting, reviewing, and finally judging as an arbiter. This process of defect consulting produces a defect consulting report, but business practices and standards of judgment will differ among consultants, and have many problems. This study reviews the structure of a defect consulting report and considers the structure's problem, which is that it is not standardized. To achieve this, data of sixteen defect consulting report were collected involving defect lawsuit cases before or after 2010. The structure and index of the defect consulting reports were then reviewed, and the results are as follows. As for a structure based on fourteen index, there are suitable that judge a outline, a cost estimate data and a consulting work item by a consulting standard. Furthermore, analysis by each common parts and private parts is considered as appropriate about consulting items and estimate by standard. However, consulting item in construction progress and responsibility period for security that related on a cause and a responsibility of defect need to complement. Meanwhile, the first thing of issues are connected a defect consulting is urgent a standardization for a defect type.

Analysis on the Structure of Defect Consulting Report in Apartment Building (공동주택 하자감정서의 구성체계 분석)

  • Park, Jun-Mo;Seo, Deok-Suk;Kim, Ok-Kyue;Park, Gil-Bum
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.166-167
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    • 2013
  • There has been a defect dispute of apartment building in Korea. The defect dispute is complicated by main issues and details of dispute. It is yet to be solved. Meanwhile, a judge does not a inspection and analysis, but, related field expert who contracted professional engineer does. As a result, defect consulting report that an important judgment is used in a defect dispute. Therefore, this study does research on structure of defect consulting report. A defect consulting report has same items, irrespective of a defect consultant as a result that check 7 indexes about 10 cases. It has different structure's details depending on each defect consultants. And, it inserts new detail or deletes existing detail, does not show clear distinction.

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Development of surface defect inspection algorithms for cold mill strip using tree structure (트리 구조를 이용한 냉연 표면흠 검사 알고리듬 개발에 관한 연구)

  • Kim, Kyung-Min;Jung, Woo-Yong;Lee, Byung-Jin;Ryu, Gyung;Park, Gui-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.365-370
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    • 1997
  • In this paper we suggest a development of surface defect inspection algorithms for cold mill strip using tree structure. The defects which exist in a surface of cold mill strip have a scattering or singular distribution. This paper consists of preprocessing, feature extraction and defect classification. By preprocessing, the binarized defect image is achieved. In this procedure, Top-hit transform, adaptive thresholding, thinning and noise rejection are used. Especially, Top-hit transform using local min/max operation diminishes the effect of bad lighting. In feature extraction, geometric, moment, co-occurrence matrix, histogram-ratio features are calculated. The histogram-ratio feature is taken from the gray-level image. For the defect classification, we suggest a tree structure of which nodes are multilayer neural network clasifiers. The proposed algorithm reduced error rate comparing to one stage structure.

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Variation of the Si-induced Gap State by the N defect at the Si/SiO2 Interface

  • Kim, Gyu-Hyeong;Jeong, Seok-Min
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.128.1-128.1
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    • 2016
  • Nitrided-metal gates on the high-${\kappa}$ dielectric material are widely studied because of their use for sub-20nm semiconductor devices and the academic interest for the evanescent states at the Si/insulator interface. Issues in these systems with the Si substrate are the electron mobility degradation and the reliability problems caused from N defects that permeates between the Si and the $SiO_2$ buffer layer interface from the nitrided-gate during the gate deposition process. Previous studies proposed the N defect structures with the gap states at the Si band gap region. However, recent experimental data shows the possibility of the most stable structure without any N defect state between the bulk Si valence band maximum (VBM) and conduction band minimum (CBM). In this talk, we present a new type of the N defect structure and the electronic structure of the proposed structure by using the first-principles calculation. We find that the pair structure of N atoms at the $Si/SiO_2$ interface has the lowest energy among the structures considered. In the electronic structure, the N pair changes the eigenvalue of the silicon-induced gap state (SIGS) that is spatially localized at the interface and energetically located just above the bulk VBM. With increase of the number of N defects, the SIGS gradually disappears in the bulk Si gap region, as a result, the system gap is increased by the N defect. We find that the SIGS shift with the N defect mainly originates from the change of the kinetic energy part of the eigenstate by the reduction of the SIGS modulation for the incorporated N defect.

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The Study of WET Cleaning Effect on Deep Trench Structure for Trench MOSFET Technology (Trench MOSFET Technology의 Deep Trench 구조에서 WET Cleaning 영향에 대한 연구)

  • Kim, Sang-Yong;Jeong, Woo-Yang;Yi, Keun-Man;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.88-89
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    • 2009
  • In this paper, we investigated about wet cleaning effect as deep trench formation methods for Power chip devices. Deep trench structure was classified by two methods, PSU (Poly Stick Up) and Non-PSU structure. In this paper, we could remove residue defect during wet. cleaning after deep trench etch process for non-PSU structure device as to change wet cleaning process condition. V-SEM result showed void image at the trench bottom site due to residue defect and residue component was oxide by EDS analysis. In order to find the reason of happening residue defect, we experimented about various process conditions. So, defect source was that oxide film was re-deposited at trench bottom by changed to hydrophobic property at substrate during hard mask removal process. Therefore, in order to removal residue defect, we added in-situ SCI during hard mask removal process, and defect was removed perfectly. And WLR (Wafer Level Reliability) test result was no difference between normal and optimized process condition.

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Crystal Defect Chemistry of Strontium Hexaaluminate Magnetoplumbite

  • Park, Jae-Gwan;A.N. Cormack
    • Korean Journal of Crystallography
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    • v.11 no.3
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    • pp.176-181
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    • 2000
  • Computer-based atomistic simulation methods are applied to address quantitatively the crystal defect chemistry of strontium hexaaluminate, SrAl/sub 12/O/sub 19/. Our calculations show that oxygen Frenkel disorder is the dominant intrinsic defect mode to be expected in the multi-component oxide, though Schottky disorder may also exist. When La and Mg enter into SrAl/sub 12/O/sub 19/. Mg prefers to occupy Al(3)4f tetrahedral sites in the magnetoplumbite structure. Our calculations also indicate that O/sub Sr/ defect is improbable in the structure.

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Evaluation of Fatigue Strength and Characteristics of Fatigue Crack Closure in SM35C Steel (중탄소강의 피로크랙 개폐구의 특성 및 피로강도의 평가)

    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.1
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    • pp.45-50
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    • 1997
  • It is not clearly known how surface defects or inclusions of a medium carbon steel affect a fatigue strength. In this study, we used SM35C specimens with spheroidized cementite structure to eliminate dependence of micro structure of fatigue crack. The investigation was carried out by behavior of crack closure at non-propagation crack and effect of the fatigue limit according to the artificial defects size. Experimental findings are obtained as follows : (1) Fatigue crack initiation point of medium carbon steel with spheroidized cementite structure is at the surface defects. (2) Non-propagating crack length of smooth specimen is equal to the critical size of defect. (3) Considering the opening and closure behavior of fatigue crack, the defect shape results in various crack opening displacement, while it does not affects the fatigue limit level of medium carbon steel with spheroidized cementite structure. (4) The critical length of the non-propagation crack of smooth specimen is the same as critical size of defect in transient area which determines threshold condition in steel with spheroidized cementite structure.

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Tomographic Imaging for Structural Health Monitoring Inspection of Containment Liner Plates using Guided Ultrasonic (유도초음파를 활용한 격납건물 라이너 플레이트 상시감시 모니터링 검사를 위한 토모그래피 영상화)

  • Park, Junpil;Cho, Younho
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.2
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    • pp.1-9
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    • 2020
  • Large-scale industrial facility structures continue to deteriorate due to the effects of operating and environmental conditions. The problems of these industrial facilities are potentially causing economic losses, environmental pollution, casualties, and national losses. Accordingly, in order to prevent disaster accidents of large structures in advance, the necessity of diagnosing structures using non-destructive inspection techniques is being highlighted. The defect occurrence, location and defect type of the structure are important parameters for predicting the remaining life of the structure, so continuous defect observation is very important. Recently, many researchers have been actively researching real-time monitoring technology to solve these problems. Structure Health Monitoring Inspection is a technology that can identify and respond to the occurrence of defects in real time, but there is a limit to check the degree of defects and the direction of growth of defects. In order to compensate for the shortcomings of these technologies, the importance of defect imaging techniques is emerging, and in order to find defects in large structures, a method of inspecting a wide range using guided ultrasonic is effective. The work presented here introduces a calculation for the shape factor for evaluation of the damaged area, as well as a variable β parameter technique to correct a damaged shape. Also, we perform research in modeling simulation and an experiment for comparison with a suggested inspection method and verify its validity. The curved structure image obtained by the advanced RAPID algorithm showed a good match between the defect area and the shape.

A Study on the Structure of Neural Network for Predicting Defect Size of Steam Generator Tube in Nuclear Power Plant (원전SG 세관 결함크기 예측을 위한 신경회로망 구조에 관한 연구)

  • Jo, Nam-Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.1
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    • pp.63-70
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    • 2010
  • In this paper, we study the structure of neural network for predicting defect size of steam generator tube. After extracting the features from the eddy current testing (ECT) signals, multi-layer neural networks are used to predict the defect size. In order to maximize the prediction performance for the defect size, we should carefully choose the structure of neural networks, especially the number of neurons in the hidden layer. In this paper, it is shown that, for the prediction of defect size, the number of neurons in the hidden layer can be efficiently determined by using cross-validation.