• Title/Summary/Keyword: edge defects

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A Video based Web Inspection System for Real-time Detection of Paper Defects during Papermaking Processes (제지공정의 실시간 결함 검출을 위한 영상 기반 웹 검사 시스템)

  • Hahn, Jong-Woo;Choi, Young-Kyu
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.79-85
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    • 2010
  • In this paper, we propose a web inspection system (WIS) for real-time detection of paper defects which can cause critical fractures during papermaking process. Our system incorporates high speed line-scan camera, lighting system, and detection algorithm to provide robust and precise detection of paper defects in real-time. Since edge defects are very crucial to the paper fractures, our system focuses on the edge region of the paper instead of inspecting the whole paper area. In our algorithm, image projection and sub-pixel operation are utilized to detect the edge defects precisely and connected component labeling and shape analysis techniques are adopted to extract various kinds of the region defects. Experimental results revealed that our web inspection system is very efficient for detecting paper defects during papermaking processes.

Effects of Post Annealing and Oxidation Processes on the Shallow Trench Etch Process (Shallow Trench 식각공정시 발생하는 결함의 후속열처리 및 산화곤정에 따른 거동에 관한 연구)

  • 이영준;황원순;김현수;이주옥;이정용;염근영
    • Journal of Surface Science and Engineering
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    • v.31 no.5
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    • pp.237-244
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    • 1998
  • In this stydy, submicron shallow trenches applied to STI(shallow tench isolation) were etched using inductively coupled $CI_2$/HBr and $CI_2/N_2$plasmas and the physical and electrical defects remaining on the etched silicon trench surfaces and the effects of various annealing and oxidation on the removal of the defects were studied. Using high resolution electron microscopy(HRTEM), Physical defects were investigated on the silicon trench surfaces etched in both 90%$CI_2$/ 10%$N_2$ and 50%$CI_2$/50%HBr. Among the areas in the tench such as trench bottom, bottom edge, and sidewall, the most dense defects were found near the trench bottom edge, and the least dense defects were found near the trench bottom edge, and least dense defects compared to that etched with ment as well as hydrogen permeation. Thermal oxidation of 200$\AA$ atthe temperature up to $1100^{\circ}C$apprars not to remove the defects formed on the etched silicon trenches for both of the etch conditions. To remove the physicall defects, an annealing treatment at the temperature high than $1000^{\circ}C$ in N for30minutes was required. Electrical defects measured using a capacitance-voltage technique showed the reduction of the defects with increasing annealing temperature, and the trends were similar to the results on the physical defects obtained using transmission electron microscopy.

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Effect of Punching Conditions on the Stretch Flange Formability of Cold rolled Steels for Deep Drawing (편칭조건이 가공용 냉연강판의 신장플랜지 성형성에 미치는 영향)

  • 전영우
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.161-164
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    • 1999
  • In order to investigate the effect of punching condition on the stretch flange formability of sheet for deep drawing hole expansion tests at various edge condition were done. Edge conditions were changed by altering tool clearances artifical defects grinding and deburring. For a determination of optimum edge condition of side panel of automobile punched section analysis and forming results were studied and the laboratory test results were used. In case of considered side panel tool clearance should be less than 15% and punched edge should be uniform without defects for safe forming

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Theoretical Investigation of Edge-modified Zigzag Graphene Nanoribbons by Scandium Metal with Pyridine-like Defects: A Potential Hydrogen Storage Material

  • Mananghaya, Michael
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.253-256
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    • 2014
  • Functionalization of zigzag graphene nanoribbon (ZGNR) segment containing 120 C atoms with pyridine (3NV-ZGNR) defects was investigated on the basis of density-functional theory (DFT) calculations, results show that edge-modified ZGNRs by Sc can adsorb multiple hydrogen molecules in a quasi-molecular fashion, thereby can be a potential candidate for hydrogen storage. The stability of Sc functionalization is dictated by a strong binding energy, suggesting a reduction of clustering of metal atoms over the metal-decorated ZGNR.

Detection of Real Defects in Composite Structures by Using Laser Measuring System (레이저 계측시스템을 이용한 복합재료 구조물의 실제결함 검출)

  • 김태형;정성균;김경석;장호섭
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.35-38
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    • 2002
  • Real defects in composite structures were detected by using laser measuring system. Four types of specimens, that is, a composite laminate, a honeycomb structure, a free-edge delamination and an adhesive joint, were used to study the applicability of ESPI and Shearography to composite structures. Thermal loading method, which can easily induce the surface deformation of specimen, was used to detect defects. Experimental results show that defects in composite structures can be easily detected by ESPI and Shearography. Moreover, it shows that ESPI and Shearography can be usefully applied to the detection of defects in various kinds of composite structures.

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Sequential conversion from line defects to atomic clusters in monolayer WS2

  • Gyeong Hee Ryu;Ren-Jie Chan
    • Applied Microscopy
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    • v.50
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    • pp.27.1-27.6
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    • 2020
  • Transition metal dichalcogenides (TMD), which is composed of a transition metal atom and chalcogen ion atoms, usually form vacancies based on the knock-on threshold of each atom. In particular, when electron beam is irradiated on a monolayer TMD such as MoS2 and WS2, S vacancies are formed preferentially, and they are aligned linearly to constitute line defects. And then, a hole is formed at the point where the successively formed line defects collide, and metal clusters are also formed at the edge of the hole. This study reports a process in which the line defects formed in a monolayer WS2 sheet expends into holes. Here, the process in which the W cluster, which always occurs at the edge of the formed hole, goes through a uniform intermediate phase is explained based on the line defects and the formation behavior of the hole. Further investigation confirms the atomic structure of the intermediate phase using annular dark field scanning transition electron microscopy (ADF-STEM) and image simulation.

Diagnosis of Edge overcoating by Air Knife Pattern Modification in CGL (용융아연도금라인에서 에어나이프 형상패턴 변경에 의한 단부과도금 진단)

  • 배용환;최홍태
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.3
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    • pp.20-28
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    • 2000
  • Air wiping technique is widely used because of easy and efficient coating control in present CGL The coating weight is controlled by nozzle header pressure. strip line speed, and the distance between strip and nozzle. Coating defects are resulted from the unbalance of these control factors and the inaccuracy of coating equipments. We investigates the main cause of coating defects, such as edge overcoating and coating deviation through various experiments. It is found that the edge overcoating is mainly come from nozzle lip type, and the coating deviation is caused by the unbalance of dynamic pressure.

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Interpretation of the lattice-shaped mura defects in thin-film-transistor liquid crystal displays

  • Woo, B.C.;Han, S.Y.
    • Journal of Information Display
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    • v.12 no.3
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    • pp.121-124
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    • 2011
  • The mechanism for lattice-shaped mura defects was proposed by characterizing the electro-optic properties of liquid crystal (LC), which showed different transmission properties between the normal and mura defect areas. An increase in the mura defect rate was observed when the dotted LC in the one drop filling (ODF) was exposed for a longer time. The dotted LC droplet at the edge evaporated more rapidly than that in the center. This resulted in a higher concentration of polar singles at the edge of the dotted LC droplet, leading to a higher ${\Delta}n$ value and higher transmittance. This implies that the reductio of the exposure time of the dotted LC to air plays a critical role in decreasing the occurrence of lattice-shaped mura defects in ODF.

Study on Scratch Reduction of HDD using Rounded-edge Slider (Rounded-edge 슬라이더를 이용한 하드디스크의 표면 스크래치 저감에 관한 연구)

  • Shin, Il-Sup;Kim, Young-Tae;Han, Je-Hee;Kim, Dae-Eun;Kang, Tae-Sik
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.3
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    • pp.184-188
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    • 2006
  • In recent years the flying height of the head/slider has been decreasing in order to increase the recording density of hard disk drive (HDD). Accordingly, it was predicted that direct contact between slider and disk surface (slider slap) can cause defects on the disk such as scratch and particle generation. In this work, we theoretically demonstrate the effect of rounded-edge slider using Hertzian contact theory. Depth and width of scratch were predicted by plowing model. Furthermore, as we fabricated rounded-edge slider, rounded-edge slider was tested and compared with sharp-edge slider. The experimental results show rounded-edge was effective for reducing scratch depth.

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