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Investigation on the Recent Research Trend in the Corrosion Behaviour of Stainless Steel Weldment

  • Kim, Hwan Tae;Kil, Sang Cheol;Hwang, Woon Suk
    • Corrosion Science and Technology
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    • v.10 no.3
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    • pp.77-79
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    • 2011
  • The research trend in the corrosion behaviour of stainless steel weldment has been reviewed. The welding technology plays an important role in the fabrication of structure such as chemical plant, power plant, because welding can influence various factors in the performance of plant and equipment. This has led to an increasing attention towards the corrosion behaviour of weldment which has been one of the major issues for both welding and corrosion research engineers. The aim of this paper is to give a short survey of the recent technical trends of welding and corrosion including the electrochemical corrosion, stress corrosion cracking, and corrosion fatigue in connection with the welding materials, welding process, and welding fabrication. This study covers the corrosion behaviour of stainless steel weldment collected from the COMPENDEX DB analysis of published papers, research subject and research institutes.

Finite Element Method (FEM) Study on Space Charge Effects in Organic Light Emitting Diodes (OLED)

  • Kim, Kwang-Sik;Hwang, Young-Wook;Won, Tae-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.4
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    • pp.467-472
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    • 2012
  • In this paper, we present a finite element method (FEM) study on the space charge effects in organic light emitting diodes. The physical model covers all the key physical processes in OLEDs, namely charge injection, transport and recombination, exciton diffusion, transfer and decay as well as light coupling, and thin-film-optics. The exciton model includes generation, diffusion, and energy transfer as well as annihilation. We assumed that the light emission originates from oscillation which thus is embodied as exciton in a stack of multilayer. We discuss the accumulation of charges at internal interfaces and their signature in the transient response as well as the electric field distribution. We also report our investigation on the influence of the insertion of the emission layer (EML) in the bilayer structure.

Suitable scanning procedures for various prosthodontic treatments and the utilization of intraoral scanner (임상가를 위한 특집 3 - 여러 보철 치료 술식에 따른 바른 스캐닝 과정과 구강스캐너의 활용)

  • Park, Ji-Manm;Park, Eun-Jin;Heo, Seong-Joo
    • The Journal of the Korean dental association
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    • v.52 no.6
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    • pp.354-362
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    • 2014
  • With the development of digital dentistry, various intra-oral scanners which acquire intraoral image without conventional impression taking and stone pouring steps have been introduced. Fixed dental prostheses such as inlay, onlay, crown, and bridge fabricated by CAD/CAM technique combined with digital impressions is getting popular due to the recent rapid progress of digital impression taking system. In comparison with traditional prosthetic procedure, the advantages of intraoral image acquiring and CAD/CAM technique are as follows; the omission of conventional impression materials, reduced workflow step, and increased efficiency by online communication with clinic and laboratory. This review article covers some opinions about the suitable scanning procedures for the various prosthodontic treatments and the utilization of digital intraoral scanner and CAD/CAM system.

Sticking Characteristics in BiSrCaCuO Thin Film Fabricated by Layer-by-Layer Sputtering Method (순차 스퍼터법으로 제작한 BiSrCaCuO 박막의 부착 특성)

  • Cheon, Min-Woo;Park, Yong-Pil;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.45-48
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    • 2003
  • BiSrCaCuO thin films were fabricated by atomic layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to $SrBi_2O_4$ by in-situ anneal.

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The Development of a Highly Portable and Low Cost SPOT Image Receiving System

  • Choi, Wook-Hyun;Shin, Dong-Seok;Kim, Tag-Gon
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.25-30
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    • 1999
  • This paper covers the development of a highly portable and low cost SPOT image data receiving system. We followed two design approaches. One is the software-based approach by which most of the real-time processing is handled by software. With the complete software-based design, it is simple to add a function for receiving any additional satellite data. Satellite-specific format handlers including error correction, decompression and decryption can easily be accommodated. On the other approach. we used a general hardware platform, IBM-PC and a low cost SCSI RAID (Redundant Away of Independent Disks), and therefore, we can make a low cost system.

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NMR methods for structural analysis of RNA: a Review

  • Kim, Nak-Kyoon;Nam, Yun-Sik;Lee, Kang-Bong
    • Journal of the Korean Magnetic Resonance Society
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    • v.18 no.1
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    • pp.5-9
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    • 2014
  • In last three decades, RNA molecules have been revealed to play the central roles in many cellular processes. Structural understanding of RNA molecules is essential to interpret their functions, and many biophysical techniques have been adopted for this purpose. NMR spectroscopy is a powerful tool to study structures and dynamics of RNA molecules, and it has been further applied to study tertiary interactions between RNA molecules, RNA-protein, and RNA-small molecules. This short article accounts for the general methods for NMR sample preparations, and also partially covers the resonance assignments of structured RNA molecules.

Fault Diagnosis of Rotating Machinery Based on Multi-Class Support Vector Machines

  • Yang Bo-Suk;Han Tian;Hwang Won-Woo
    • Journal of Mechanical Science and Technology
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    • v.19 no.3
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    • pp.846-859
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    • 2005
  • Support vector machines (SVMs) have become one of the most popular approaches to learning from examples and have many potential applications in science and engineering. However, their applications in fault diagnosis of rotating machinery are rather limited. Most of the published papers focus on some special fault diagnoses. This study covers the overall diagnosis procedures on most of the faults experienced in rotating machinery and examines the performance of different SVMs strategies. The excellent characteristics of SVMs are demonstrated by comparing the results obtained by artificial neural networks (ANNs) using vibration signals of a fault simulator.

A Study on an Image Noise Erase Method By to be an Image Noise Frequent Occur for Raining, in Measurement Machine Vision System for using CCD Camera Of Pantograph Sliding Plate (팬터그래프 습판마모의 머신 비젼 측정에서 우천시 발생하는 영상의 노이즈 제거방법에 대한 연구)

  • Lee, Seong-Gwon;Lee, Dae-Won;Kang, Seung-Wook;Oh, Sang-Yoon
    • Proceedings of the KIEE Conference
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    • 2007.11c
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    • pp.191-193
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    • 2007
  • Pantograph sliding plate abrasion auto-detect system, one of the electric rail car auto-detecting devices, is a system that decides how much abrasion and when to replace without an inspector physically looking at the abrasion on the wet plate using machine vision, a cutting-edge technology. This paper covers the cause of deteriorating reliability that affects pantograph wet plate edge detection due to noise added to the video when it rains. In order to remove such noise, problems should be checked through Smoothing, Averaging mask and Median filter using filtering technique and stable edge detection without being affected by noise should be induced in video measurement used in machine vision technology.

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Flow Analysis of Cyclone-Cartridge Filter Gausing Collector (사이클론-카트리지필터 일체형 가우징 집진기의 유동해석)

  • Jang, Sung-Cheol;Jung, Dae-Young;Cho, Jung-Sick
    • Journal of the Korean Society of Industry Convergence
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    • v.21 no.3
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    • pp.133-139
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    • 2018
  • Precipitator is the most widespread device used to separate dust particles from the exhaust gas. In the shipyard, welding umbrellas, spark protection covers, and ventilators are not purchased and used for the work place to capture the flames and high temperature metal dust generated during the gardening process. In particular, a thorough analysis of design factors, such as capture rate, collection capacity calculation, filter speed, and materials selection, is required since spatial constraints are followed by structures, etc. In this study, conceived to address problems such as this cyclone and filtration filter system that combines all-in-one gausing collector prototype. Assessed through interpretation through the validity of the design and reliability.

Predicting Audit Reports Using Meta-Heuristic Algorithms

  • Valipour, Hashem;Salehi, Fatemeh;Bahrami, Mostafa
    • Journal of Distribution Science
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    • v.11 no.6
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    • pp.13-19
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    • 2013
  • Purpose - This study aims to predict the audit reports of listed companies on the Tehran Stock Exchange by using meta-heuristic algorithms. Research design, data, methodology - This applied research aims to predict auditors reports' using meta-heuristic methods (i.e., neural networks, the ANFIS, and a genetic algorithm). The sample includes all firms listed on the Tehran Stock Exchange. The research covers the seven years between 2005 and 2011. Results - The results show that the ANFIS model using fuzzy clustering and a least-squares back propagation algorithm has the best performance among the tested models, with an error rate of 4% for incorrect predictions and 96% for correct predictions. Conclusion - A decision tree was used with ten independent variables and one dependent variable the less important variables were removed, leaving only those variables with the greatest effect on auditor opinion (i.e., net-profit-to-sales ratio, current ratio, quick ratio, inventory turnover, collection period, and debt coverage ratio).