• Title/Summary/Keyword: Back-plate

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FEM Analysis of spring back in bending process of center plate for molten carbonate fuel cell (용융탄산염 연료전지용 금속분리판 굽힘 공정의 유한요소 해석을 통한 스프링백 분석)

  • Lee, C.H.;Ryu, S.M.;Yang, D.Y.;Kim, Y.J.;Kang, D.W.;Chang, I.G.;Lee, T.W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.220-223
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    • 2009
  • Metallic bipolar plate for molten carbonate fuel cell(MCFC) is composed of the shielded slot plate and the center plate. Among these, the center plate plays an important role in gas sealing. Therefore, manufacturing of the center plate is considered one of the key issues in MCFC. The center plate is manufactured by bending process. In bending process, springback and recoiling are two main problems. By using the modified punch shape with 'step', springback and recoil are reduced. The aim of this article is to find the effect of modified punch shape. So, the bending stress along thickness direction and material direction were investigated using FEM.

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Stress Analysis at the Contact Boundary between the Work Roll and the Back-up Roll for a SmartCrown Roll Profile Shape (SmartCrown Roll Profile 형상에 따른 Work Roll과 Back-up Roll 접촉경계면의 응력해석)

  • Song, S.H.;Kim, S.R.;Kim, K.W.
    • Transactions of Materials Processing
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    • v.24 no.3
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    • pp.212-217
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    • 2015
  • SmartCrown is a system to control the plate crown by shifting the sine-shaped work rolls in the axial direction. The control range of the plate crown depends on a depth of sine-shaped roll profile because the roll radius varies continuously along the axial direction. When the roll profile is changed to improve the control range, the contact stress between the work roll and the back-up roll also changes. In the current study, the contact stress for various profiles and rolling conditions were analyzed using the finite element method and compared with results from Hertzian contact theory. A submodel method is used to increase the accuracy of the finite element analysis. The analysis results showed that the maximum increase in the contact stress was only 53MPa, so it is anticipated that no back-up roll spalling will occur.

Origin of the East Sea (Japan Sea) and Plate Tectonics (東海의 起源과 板構造論)

  • Kim, So Gu
    • 한국해양학회지
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    • v.19 no.1
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    • pp.94-102
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    • 1984
  • The origin of the East sea is discussed in the light of modern geophysical theories such as plate tectonics and sea-floor spreading. The origin of the East Sea was due to the tensional force of the back-arc spreading which was initiated as early as late Cretaceous time of Paleocene. The spreading was asymmetric with a fast movement of eastward or southeastward and a slow westward motions. The spreading, however, was confined to the East Sea due to the change of the Pacific Plate north-northwest to west-northwest during Eocene time. Further intensifying research based on more accurate seismic data as well as on geophysical and geological informations should be carried out continuously to understand if the spreading of the Japan Sea died out due to triple junction formed by mention of the Pacific, the Eurasian, and the Philippine plates since the Quaternary.

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Evaluation of the characteristics of the reflection plate to measure defects in the invisible area using infrared thermography

  • Kim, Sang Chae;Park, Il Cheol;Kang, Chan Geun;Jung, Hyunchul;Chung, Woon Kwan;Kim, Kyeong Suk
    • Nuclear Engineering and Technology
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    • v.52 no.4
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    • pp.856-862
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    • 2020
  • Defect inspection system for industrial applications takes the important portion. Non-destructive inspection method has been significantly improved. Infrared thermography, as one of method for non-destructive inspection, can provide relatively precise data and quick inspection time. This study, it was performed to measure defect according to the measurement limit of the non-visible areas such as the back surface of the pipe using reflection plate using reflection plate based on Infrared thermography. The materials of the reflection plate were determined in consideration of the space limitation and the thermal characteristics, and defects were detected by the manufactured reflection plate. Detection of defect in non-visible area using the candidate materials for reflection plate was conducted.

A Study on Back Bead Formation in Inclined-up Position of Flasma An Orbital Welding (플라즈마 아크 오비탈 용접의 경사상진자세에서 이면비드 형성에 관한 연구)

  • Kim, Hyo-Won;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.27 no.1
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    • pp.71-78
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    • 2009
  • In the circumferential welding of pipe, welding phenomenon changes with the position of pipe. Especially in the overhead position, back bead of vertical-up position would be sunk. To investigate the size of back bead and keyhole with the change of the flow rate of pilot and shield gas at each position, bead-on plate welds were conducted on 6mm thickness SS400 with inclined-up position. When the rest of welding conditions remained constant, the width of back bead was increased as the flow rate of pilot gas was increased. And back bead tended to convex as the flow rate of shield gas was increased.

Back Scatter Radiation이 CR영상(影像)에 미치는 영향(影響)

  • Lee, Hu-Min;Kim, Hak-Seong;Jo, Nam-Su;Go, Seung-Il
    • Korean Journal of Digital Imaging in Medicine
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    • v.2 no.1
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    • pp.92-95
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    • 1996
  • Computed Radiography(CR) is a relatively new technology that relies on an image plate(IP) as an alternate x-ray sensor to screen/film. Standard CR cassettes do not have lead foil behind the IP to control scatter radiation. The result of this study indicate that such control is needed. In most screen/film cassettes, that lines the rear of the cassette eliminates back scatter radiation. This study was performed to Investigate on the effects of back scatter in CR images by size of exposure field, distance between the CR cassette and the wall of radiography room. 1. It showed artifacts from hinges and clips located on the back of CR cassette by back scatter radiation. 2. The greater effects of back scatter radiation in CR images was attributed to the greater size of exposure field and the longer distance between the CR cassette and the wall of radiography room.

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Acromion Fracture after Hook Plate Fixation for Distal Clavicle Injury: A Report of 2 Cases

  • Kang, Suk;Lee, Ho Min;Back, In Hwa
    • Clinics in Shoulder and Elbow
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    • v.19 no.3
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    • pp.168-171
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    • 2016
  • Fractures at the lateral end of the clavicle inevitably require surgical treatment as there is high potential for delayed union or nonunion. Acromioclavicular dislocation also requires stable and solid fixation for healing, and surgical treatment is recommended for the maintenance of joint function. The hook plate maintains the biomechanics of the acromioclavicular joint, enabling early range of motion. Therefore, for the past 10 years, the hook plate has been widely used in distal clavicle fractures and acromioclavicular joint injuries. However, the hook plate is associated with several complications, such as proximal clavicle fractures, widening of the hook hole, rotator cuff tear, subacromial impingement, and often acromial fractures. We report on two unusual cases of acromion fracture after hook plate fixation in patients with distal clavicle fracture and acromioclavicular dislocation alongside a literature review.

A Study on improving the performance of License Plate Recognition (자동차 번호판 인식 성능 향상에 관한 연구)

  • Eom, Gi-Yeol
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2006.11a
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    • pp.203-207
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    • 2006
  • Nowadays, Cars are continuing to grow at an alarming rate but they also cause many problems such as traffic accident, pollutions and so on. One of the most effective methods that prevent traffic accidents is the use of traffic monitoring systems, which are already widely used in many countries. The monitoring system is beginning to be used in domestic recently. An intelligent monitoring system generates photo images of cars as well as identifies cars by recognizing their plates. That is, the system automatically recognizes characters of vehicle plates. An automatic vehicle plate recognition consists of two main module: a vehicle plate locating module and a vehicle plate number identification module. We study for a vehicle plate number identification module in this paper. We use image preprocessing, feature extraction, multi-layer neural networks for recognizing characters of vehicle plates and we present a feature-comparison method for improving the performance of vehicle plate number identification module. In the experiment on identifying vehicle plate number, 300 images taken from various scenes were used. Of which, 8 images have been failed to identify vehicle plate number and the overall rate of success for our vehicle plate recognition algorithm is 98%.

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Numerical Analysis of Noise Reduction and Back-pressure for a Simple Expansion Chamber with a Partition (내부 파티션을 갖는 단순확장관의 소음저감 및 배압특성의 전산해석)

  • Kim, Yeon Woo;Jeong, Weuibong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.11
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    • pp.883-889
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    • 2014
  • Mufflers have been widely used in the exhaust system to reduce the noise. However, installing muffler may deteriorate the efficiency due to the increase of back pressure. Mufflers usually consist of partition plates and perforated holes in a expansion chamber. In this paper, the influences of the location of the partition and hole on the acoustic TL and back pressure were examined. The acoustic TL was predicted using virtual lab commercial software, while the back pressure were predicted using CFX commercial software. The results were used to set up a database for finding their trends. The optimal muffler model in user-interested frequency range could be selected by analyzing this database.