• 제목/요약/키워드: cause of defects

검색결과 623건 처리시간 0.026초

Development of UV-curable paste for micro mold transfer process of barrier ribs of PDPs

  • Kim, Yoo-Seong;Koh, Tae-geum;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.917-920
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    • 2006
  • In an attempt to reduce processing cost and to improve resolution of PDPs, micro mold transfer processing route for barrier ribs of plasma display panel was developed. In this study, the parameters that may cause defects during the process were identified, which include the shrinkage during UV curing process, stress due to evaporation of organic components, and sintering shrinkage. Considering such parameters, UV curable paste was developed and barrier ribs of PDPs were successfully processed via the process. In addition, the process was successfully applied for the processing of barrier ribs with embedded counter electrodes.

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Speckle Interferometric Detection of Defects on the backside of steel plate (스페클 간섭계를 이용한 평판 이면결함의 검출 특성)

  • 김동한;장석원;장경영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.195-198
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    • 2001
  • Backside defect of plate structure may grow due to fatigue or overload to cause critical failure during operation, so it is important to detect this kind of defect in line. For this purpose, nondestructive, non-contact and highly sensitive method is required. ESPI and Shearography are considered as useful method to satisfy these requirements. In this paper, the possibility of application of ESPI and Shearography to detect the backside defect of steel plate and to quantify the defect size was tested. For the experiment, some steel plates with defect on the backside were prepared. Experimental results for these plates showed that location and size of defect could be detected correctly by both of ESPI and Shearography.

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Congenital Abnormalitis in Korean Native Goat with Akabane Virus (재래 산양에서의 아까바네 감염에 의한 척추만곡증)

  • 한동운
    • Journal of Veterinary Clinics
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    • 제20권3호
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    • pp.427-430
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    • 2003
  • Akabane virus is a cause of severe congenital defects, but adult animals show no signs of infection. In this study, congenital abnormalitis associated with Akabane virus infection in Korean native goat. The prevalence of serum neutralizing antibodies to Akabane virus in goat population was investigated, indicating that approximately 30% of goats in Korea were seropositive(36/120). The mother goats have the highest titers of neutralizing antibodies, as 1:128. And also there showed seropositive of Akabane virus in newborn fetus fluids. The necropsy results of newborn fetus visceral organs were appeared normal. These findings provide that Akabane virus is the ethiological agent of congenital abnormalitis and stillbirth. Our results suggest that goat in natural situations are part of the Akabane virus transmission cycle.

Analysis of Wire/Bar Rolling Process of High Speed Steel for Prevention of Center Fusion (고속도강 선.봉재의 중심부 용융현상방지를 위한 압연공정 해석)

  • Lee, S.Y.;Jeong, H.T.;Ha, T.K.;Jung, J.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2007년도 추계학술대회 논문집
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    • pp.318-321
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    • 2007
  • The temperature distribution of high speed tool steel wire/bar during high speed hot rolling procedures has been studied in this study. The tool steels wire/bar show severe temperature gradient during rolling procedures and the temperature of center part much higher than that of the surface. This temperature gradient accumulated after every rolling procedure and the center of rolled wire/bar could be remelt in a certain stage to cause inside defects. In the present study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, has been discussed to prevent the temperature increases of center wire/bar.

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The Solid-electrolyte Characteristics of Ag-doped Germanium Selenide for Manufacturing of Programmable Metallization Cell (Programmable Metallization Cell 제작을 위한 Ag-doped Germanium Selenide의 고체전해질 특성)

  • Nam, Ki-Hyun;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • 제22권5호
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    • pp.382-385
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    • 2009
  • In this study, we studied switching characteristics of germanium selenide(Ge-Se)/silver(Ag) contact formed by photodoping for use in programmable metallization cell devices. We have been investigated the switching characteristics of Ag-doped chalcogenide thin films. Changed resistance range by direction of applied voltage is about $1\;M{\Omega}$ $\sim$ hundreds of $\Omega$. The cause of these resistance change can be thought the same phenomenon such as resistance variation of PMC-RAM. The results imply that the separated Ag-ions react the atoms or defects in chalcogenide thin films.

Diagnosis of Coating Deviation in Continuous Galvanizing Line (연속용융아연 도금라인의 도금편차 진단)

  • 배용환
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권2호
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    • pp.192-199
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    • 2002
  • In continuous galvanizing process, the mass of zinc deposited and its distribution are controlled by the air pressure, effective distance from the air knife nozzle to the steel strip surface and line speed. Coating defects are resulted from the unbalance of these control factors and the inaccuracy of coating equipments. This paper investigates the main cause of coating deviation and a new air knife system for control of coating thickness was developed. We investigate dynamic pressure variation by air knife types. It is found that the coating deviation is caused by the unbalance of dynamic pressure, the irregularity of strip position, and the strip vibration. Formulating a useful coating model by using present working condition, an optimal working condition is suggested. The productivity and coating quality are improved by applying the result of this research at the shop floor.

A New Method for Color Feature Representation of Color Image in Content-Based Image Retrieval Projection Maps

  • Kim, Won-Ill
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • 제9권2호
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    • pp.73-79
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    • 2010
  • The most popular technique for image retrieval in a heterogeneous collection of color images is the comparison of images based on their color histogram. The color histogram describes the distribution of colors in the color space of a color image. In the most image retrieval systems, the color histogram is used to compute similarities between the query image and all the images in a database. But, small changes in the resolution, scaling, and illumination may cause important modifications of the color histogram, and so two color images may be considered to be very different from each other even though they have completely related semantics. A new method of color feature representation based on the 3-dimensional RGB color map is proposed to improve the defects of the color histogram. The proposed method is based on the three 2-dimensional projection map evaluated by projecting the RGB color space on the RG, GB, and BR surfaces. The experimental results reveal that the proposed is less sensitive to small changes in the scene and that achieve higher retrieval performances than the traditional color histogram.

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A New Method for Color Feature Representation of Color Image in Content-Based Image Retrieval - 2D Projection Maps

  • Ha, Seok-Wun
    • Journal of information and communication convergence engineering
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    • 제2권2호
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    • pp.123-127
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    • 2004
  • The most popular technique for image retrieval in a heterogeneous collection of color images is the comparison of images based on their color histogram. The color histogram describes the distribution of colors in the color space of a color image. In the most image retrieval systems, the color histogram is used to compute similarities between the query image and all the images in a database. But, small changes in the resolution, scaling, and illumination may cause important modifications of the color histogram, and so two color images may be considered to be very different from each other even though they have completely related semantics. A new method of color feature representation based on the 3-dimensional RGB color map is proposed to improve the defects of the color histogram. The proposed method is based on the three 2-dimensional projection map evaluated by projecting the RGB color space on the RG, GB, and BR surfaces. The experimental results reveal that the proposed is less sensitive to small changes in the scene and that achieve higher retrieval performances than the traditional color histogram.

Temperature Distribution of High Speed Tool Steel Rod During High Speed Hot Rolling Procedure (고속열간압연에서 고속도공구강 봉재의 온도분포 해석)

  • Jeong, Hyo Tae;Lee, Soo Yeon;Ha, Tae Kwon;Jung, Jae Young
    • Korean Journal of Metals and Materials
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    • 제46권3호
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    • pp.150-158
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    • 2008
  • The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod.

Camber Management of Continuous Preflex Girder Bridges (연속형 프리플렉스 합성거더 교량의 캠버 관리)

  • Kim, Jong-In;Choi, Young-Wha
    • Journal of the Korean Society of Industry Convergence
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    • 제7권4호
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    • pp.433-441
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    • 2004
  • This paper presents a strategy for the quality assurance of the continuous preflex composite girder bridge through the camber management of the girder during construction. The construction stages which require welding, balanced preflexion loads at the ends, etc. may cause unexpected large deformation to the preflex girder. Furthermore, these defects can be detected by measurements and analyses of the girder behavior which is sometimes time consuming. In the present study, preflex girder's camber data at equally spaced nodes in each construction stage are obtained and analyzed for the quality control of thee span continuous preflex girder composite bridge.

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