• 제목/요약/키워드: Focusing grid

검색결과 87건 처리시간 0.027초

Image J 프로그램을 이용한 격자집속거리와 격자비에 따른 영상비교평가 (Using Image J program, compared of focusing distance and grid rate)

  • 서원주;서정범;이종웅
    • 대한디지털의료영상학회논문지
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    • 제14권1호
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    • pp.37-42
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    • 2012
  • Pediatric head and neck phantom, using the rate by focusing distance and grid images, Image J using the Quality Assessment and Dose Area Product compared. X-ray laboratory equipment due to the Philips Digital DIAGNOST a 110 cm FFD set and using ACE Non-grid, focusing distance 110 cm (12 : 1), 140 cm (12 : 1), 180 cm (8 : 1) Focused grid, Acryl Phantom (Fluke Model 76-2 Series Phantom) 15.24 cm, by resolution chart image acquisition, image evaluation program (Image J Ver. 1.4.3.67, USA) imaging experiments were analyzed using. Dose Area Product in the Non Grid 0.028 $mGy{\cdot}cm^2$, focusing distance 110 cm (12 : 1), the 0.129 $mGy{\cdot}cm^2$, 140 cm (12 : 1), the 0.135 $mGy{\cdot}cm^2$, 180 cm (8 : 1) was measured with a 0.110 $mGy{\cdot}cm^2$ Non Grid, focusing distance 110 cm (12 : 1), 140 cm (12 : 1), 180 cm (8 : 1) Image obtained when grid using the image J program focusing distance 110 cm with grid based on the measured SNR and PSNR Non Grid if the SNR the 17.307 dB, PSNR of the 20.002 dB, if the SNR 28.755 dB, PSNR was measured by the 31.451 dB. Image J image analysis through the streets, rather than focusing on grid by the rate that could see an increase in dose. Select the grid by a small dose rate reduction is possible.

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Privacy Enhanced Security Mechanism for Grid Applications

  • Park, Sang-Bae
    • International Journal of Contents
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    • 제6권3호
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    • pp.15-18
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    • 2010
  • Grid system is based on the Grid Security Infrastructure (GSI). GSI uses user's proxy to guarantee availability among multi-trust domains. Since grid system has been developed focusing on availability, GSI provides authentication and authorization performed by systems, but there are lacks of privacy consideration. For this reason, some researchers decide to use their own cluster system and do not want to use public grid systems. In this paper, we introduce a new privacy enhanced security mechanism for grid systems. With this mechanism, user can participate in resource allocation and authorization to user's contents more actively. This mechanism does not need to change previous middleware and minimize the computational overheads.

가상화를 이용한 위탁형 그리드 서비스 거래망 모델 (Third Party Grid Service Maketplace Model using Virtualization)

  • 장성호;이종식
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2005년도 추계학술대회 및 정기총회
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    • pp.45-50
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    • 2005
  • Research and development of grid computing ware mainly focused on high performance computing field such as large-scale computing operation. Many companies and organizations concentrated on existing computational grid. However, service grid focusing on enterprise environments has been noticed gradually. Grid service providers of service grid construct diverse and specialized services and provide service resources that have economic feasibility to grid users. But, service resources are geographically dispersed and divided into many classes and have individual owners and management policies. In order to utilize and allocate resources effectively, service grid needs a resource management model that handles and manages heterogeneous resources of service grid. Therefore, this paper presents the third party grid service marketplace model using virtualization to solve problems of grid service resource management. Also, this paper proposes resource dealing mechanism and pricing algorithms applicable for service grid. Empirical results show usefulness and efficiency of the third party grid service marketplace model in comparison with typical economic models for grid resource management such as single auction model and double auction model.

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그리드 프래닝에 의한 F.L 라이트의 공간패턴에 관한 연구 -프래리와 유소니언 주택을 중심으로- (A Study for F.L. Wright's Space Pattern by Grid Planning -Focusing on Prairie and Usonian Houses-)

  • 전영미
    • 한국실내디자인학회논문집
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    • 제17호
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    • pp.181-186
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    • 1998
  • Grid serves as an auxiliary instrument that explains design logically and objectively when you designing an interior. But grid is unacceptable to the space which is produced by designer who wants to express a design subjectively. Because grid makes usual and standardized space without flexibility. Changing and developing a fundamental unit with modern touch is going to be a way compensate for the weakpoint Also versatile grid unit can support the designer's subjective intention. This study focuses on the limits of Wright's house which show interior space aestheically through grid planing. In this paper Wright's uniqe interior space pattern will be examined through the selection of some of his works specifically the Prairies and Usonians whose transforming is noticable as Wright house and analysis about formation process of grid planning characteristics and spaces is continued. With all this analysis I'm, going to look over Wright's philosophy and pattern that is usually intended by his grid planning.

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반사경 내부 유동의 초점 형성에 관한 고해상도 수치 해석 (A HIGH-RESOLUTION NUMERICAL ANALYSIS OF SHOCK FOCUSING IN CONCAVE REFLECTORS)

  • 정연규;장근식
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 춘계학술대회논문집
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    • pp.170-175
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    • 2009
  • Shock focusing is related with explosive release of shock wave energy on a narrow spot in a short duration of time triggering a spontaneous high pressure near the focal point. It is well known that reflection of planar incident shock wave from the metallic concave mirror such as ellipsoidal, paraboloidal or hemispherical cavities will focus on a focal point. We intend to improve the computational results using a wave propagation algorithm and to resolve the mushroom-like structure. For computation of the concave cavity flow, it is not easy to use a single-block mesh because of the many singular points in geometry and coordinates. We have employed a uniform Cartesian-grid method for the wave propagation algorithm.

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스마트그리드산업에서의 유망 IT R&D 분야 도출 (A Study on the Prospective IT R&D Fields in the Smart Grid Area)

  • 심진보;하영욱
    • 한국통신학회논문지
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    • 제35권9B호
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    • pp.1416-1427
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    • 2010
  • 국내 스마트그리드 관련 기술 수준은 일부 분야를 제외하고 선진국들의 수준에 미치지 못하는 것으로 평가되고있다. 이러한 상황 하에서, 본 연구는 스마트그리드 발전의 필수요소인 관련 IT기술을 조망해보고, 스마트그리드 분야에서의 유망 IT R&D분야를 도출하고자 하는 목적으로 수행되었다. 유망 IT R&D 분야의 도출을 위해 스마트그리드 관련 IT기술들의 경제성, 정책부합성, 기술타당성을 평가하는 2단계의 과정을 거쳤고, 그 결과 (1) 센서, (2) 정보보호, (3) AMI 미들웨어, (4) 전력관리의 4대 분야가 유망 분야로 선정되었다. 이 가운데 센서와 AMI 미들웨어 분야는 경제적으로 타당성이 높은 분야이기 때문에 핵심기술 개발에 집중하여 선도적 제품을 타국가보다 세계시장에 빨리 내놓는 전략(Focusing & First Mover Strategy)이 요구된다. 정보보호 분야에서는 국가 기간산업 차원에서의 전력망 안정성 확보 기술 분야와 전력사용자 측면에서의 개인 기업정보보호 기술 분야로 나누어 R&D를 수행하는 R&D Sharing 전략이 기술개발의 효율성을 증대시킬 수 있겠다. 그리고 전력관리 분야는 한국전력 주도로 관리시스템의 요소기술들을 공동 개발하는 전략적 제휴(Strategic Alliance)가 바람직할 것이다.

Single-step 전자빔 묘화 장치를 이용한 Focusing Grating Coupler 제작 연구 (Fabrication technology of the focusing grating coupler using single-step electron beam lithography)

  • 김태엽;김약연;손영준;한기평;백문철;김해성;신동훈;이진구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.976-979
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    • 2002
  • A focusing grating coupler (FGC) was not fabricated by the 'Continuous Path Control' writing strategy but by an electron-beam lithography system of more general exposure mode, which matches not only the address grid with the grating period but also an integer multiple of the address grid resolution (5 nm), To more simplify the fabrication, we are able to reduce a process step without large decrease of pattern quality by excluding a conducting material or layer such as metal (Al, Cr, Au), which are deposited on top or bottom of an e-beam resist to prevent charge build-up during e-beam exposure. A grating pitch period and an aperture feature size of the FGC designed and fabricated by e-beam lithography and reactive ion etching were ranged over 384.3 nm to 448.2 nm, and $0.5{\times}0.5mm^2$ area, respectively, This fabrication method presented will reduce processing time and improve the grating quality by means of a consideration of the address grid resolpution, grating direction, pitch size and shapes when exposing. Here our investigations concentrate on the design and efficient fabrication results of the FGC for coupling from slab waveguide to a spot in free space.

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A Case Study of the Base Technology for the Smart Grid Security: Focusing on a Performance Improvement of the Basic Algorithm for the DDoS Attacks Detection Using CUDA

  • Huh, Jun-Ho;Seo, Kyungryong
    • 한국멀티미디어학회논문지
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    • 제19권2호
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    • pp.411-417
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    • 2016
  • Since the development of Graphic Processing Unit (GPU) in 1999, the development speed of GPUs has become much faster than that of CPUs and currently, the computational power of GPUs exceeds CPUs dozens and hundreds times in terms of decimal calculations and costs much less. Owing to recent technological development of hardwares, general-purpose computing and utilization using GPUs are on the rise. Thus, in this paper, we have identified the elements to be considered for the Smart Grid Security. Focusing on a Performance Improvement of the Basic Algorithm for the Stateful Inspection to Detect DDoS Attacks using CUDA. In the program, we compared the search speeds of GPU against CPU while they search for the suffix trees. For the computation, the system constraints and specifications were made identical during the experiment. We were able to understand from the results of the experiment that the problem-solving capability improves when GPU is used. The other finding was that performance of the system had been enhanced when shared memory was used explicitly instead of a global memory as the volume of data became larger.

패턴 형상 및 입사각에 따른 Wire Grid Polarizer의 편광 특성 해석 (Analysis of Polarization Characteristics of the Wire Grid Polarizer According to Pattern shapes and incident angle)

  • 정지윤;조영태;정윤교
    • 한국기계가공학회지
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    • 제13권3호
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    • pp.111-117
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    • 2014
  • With the development of technology, the display industry has been focusing on the development of new types of displays, such as bendable and wearable displays. However, the PVA/TAC polarizing film used in the manufacturing of a normal display is associated with low luminance and low efficiency. If the existing polarization film is replaced with a wire grid polarizer, it is possible to reduce the thickness significantly. Moreover enhanced brightness can also be expected. This study confirms the optical properties of the WGP through a simulation.

Fabrication Technology of the Focusing Grating Coupler using Single-step Electron Beam Lithography

  • Kim, Tae-Youb;Kim, Yark-Yeon;Han, Gee-Pyeong;Paek, Mun-Cheol;Kim, Hae-Sung;Lim, Byeong-Ok;Kim, Sung-Chan;Shin, Dong-Hoon;Rhee, Jin-Koo
    • Transactions on Electrical and Electronic Materials
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    • 제3권1호
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    • pp.30-37
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    • 2002
  • A focusing grating coupler (FGC) was not fabricated by the 'Continuous Path Control'writing strategy but by an electron-beam lithography system of more general exposure mode, which matches not only the address grid with the grating period but also an integer multiple of the address grid resolution (5 nm). To more simplify the fabrication, we are able to reduce a process step without large decrease of pattern quality by excluding a conducting material or layer such as metal (Al, Cr, Au), which are deposited on top or bottom of an e-beam resist to prevent charge build-up during e-beam exposure. A grating pitch period and an aperture feature size of the FGC designed and fabricated by e-beam lithography and reactive ion etching were ranged over 384.3 nm to 448.2 nm, and 0.5 $\times$ 0.5 mm$^2$area, respectively. This fabrication method presented will reduce processing time and improve the grating quality by means of a consideration of the address grid resolution, grating direction, pitch size and shapes when exposing. Here our investigations concentrate on the design and efficient fabrication results of the FGC for coupling from slab waveguide to a spot in free space.