• 제목/요약/키워드: Block

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서맥 의존성 완전 방실차단 1례 (A Case of Bradycardia-Dependent Complete Atrioventricular(A-V) Block)

  • 이재익;김영조;심봉섭;이현우
    • Journal of Yeungnam Medical Science
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    • 제6권2호
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    • pp.241-245
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    • 1989
  • 저자들은 안정 와위시 완전 방실차단을 보이고, 좌위로 체위변동과 아트로핀 투여로 야기된 빈맥시 1도 방실차단으로 호전된 서맥의존성 방실차단의 예를 경험하였으며, 인공 심박조율기로 효과적으로 치료하였기에 문헌 고찰과 함께 보고하는 바이다.

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블록 공중합체 3차원 패턴의 제조 방법 및 그 구조 특성 (Fabrication of Free-Standing Three-Dimensional Block Copolymer Patterns on Substrate)

  • 최홍균
    • 한국재료학회지
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    • 제29권12호
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    • pp.804-811
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    • 2019
  • As the importance of three-dimensiona (3D) nano patterns and structures has recently emerged, interest in the study of 3D structures of block copolymers has increased. However, most existing studies on block copolymer 3D patterns on substrates are limited to simple 3D structures such as a multi-layered forms. In this study, we propose an experimental method for realizing free-standing 3D block copolymer patterns on substrates using an e-beam lithographic template and film transfer method. The block copolymer 3D structure formed in wide hole templates are similar to simple multi-layered structures; however, as the width of the hole template become narrower, more complex block copolymer 3D structures are formed in which the upper and lower layer structures are interconnected. Furthermore, we introduce a method to fabricate novel block copolymer structures in which the 2D planar structures are connected to 3D complex structures. Proposed 3D block copolymer fabrication method provides a framework for generation of unconventional 3D structures of block copolymer, which can be useful for next generation 3D devices.

PC를 이용한 실시간 프랙탈 부호화 구현 (Real-time fractal coding implementation using the PC)

  • 김재철;박종식
    • 한국통신학회논문지
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    • 제21권11호
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    • pp.2789-2800
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    • 1996
  • Real time fractal coding for successive QCIF 144*176 luminance images has been implemented on a 50MHz IBM 486 personal computer. To satisfy the frame encoding speed and data compression ratio, following algorithms are adopted. In order to minimize encoding time, extension SAS being not searching of domain blocks is used. for reducing the bits per pixel, conventioal 4*4 range block is extended to 8*8 range block. and range block extension decrease quality of decoded image. For improvement quality of decoded image, the paper apply quad-tree partition mothod. In order to divide **8 range block, self-simiarity is compared 8*8 range block with spatial contractive transformed 8*8 domain block. According to self-simiarity, the block is partitioned and owing to block partition, increased encoding time is minimized. According to self-simiarity of 8*8 range block and spatial contractive transformed 8*8 domain block, number of fractal factor is varied. Simultaneously with minimizing the decrement of decoded image's quality, transmittion rate and encoding time is shorted. The results enable us to process the real-time fractal coding. For the claire test image, the average PSNR was 32.4dB, 0.12 bit rates and 33ms coding time per frame.

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블록 분류와 적응적 필터링을 이용한 후처리에서의 블록화 현상 제거 방법 (Postprocessing Method for Blocking Artifact Reduction Using Block Classification and Adaptive Filtering)

  • 이석환;권기구;김병주;이승진;권성근;이건일
    • 한국통신학회논문지
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    • 제27권6A호
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    • pp.592-601
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    • 2002
  • 본 논문에서는 블록 분류와 적응적 필터링을 이용하여 블록 기반 부호화에서의 블록화 현상을 제거하는 후처리 방법을 제안하였다. 제안한 방법에서는 블록 분류, 적응적인 블록 간 필터링, 및 블록 내 필터링의 단계로 이루어진다. 먼저, 각 블록을 8$\times$8 DCT 계수 분포에 따라 7개의 클래스로 분류하고, 인접한 두 블록의 클래스 걸보에 따라 적응적인 블록 간 필터링을 수행한다. 그리고 복잡한 클래스로 분류된 블록에 대하여 에지맵을 이용한 블록 내 필터링을 수행한다. 실험결과로부터 제안한 방법이 기존의 방법에 비하여 객관적 화질 및 주관적 화질 측면에서 보다 우수함을 확인하였다.

Compression Behavior of Form Block Walls Corresponding to the Strength of Block and Grout Concrete

  • Seo, S.Y.;Jeon, S.M.;Kim, K.T.;Kuroki, M.;Kikuchi, K.
    • International Journal of Concrete Structures and Materials
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    • 제9권1호
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    • pp.21-33
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    • 2015
  • This study aimed to present a reinforced concrete block system that reduces the flange thickness of the existing form block used in new buildings and optimizes the web form, and can thus capable of being used in the seismic retrofit of new and existing buildings. By conducting a compression test and finite element analysis based on the block and grouted concrete strength, it attempted to determine the compression capacity of the form block that can be used in new construction and seismic retrofit. As a result, the comparison of the strength equation from Architectural Institute of Japan to the prism compression test showed that the mortar coefficient of 0.55 was suitable instead of 0.75 recommended in the equation. The stress-strain relation of the block was proposed as a bi-linear model based on the compression test result of the single form block. Using the proposed model, finite element analysis was conducted on the prism specimens, and it was shown that the proposed model predicted the compression behavior of the form block appropriately.

경막외 차단술 후유증을 동반한 유추간판탈출증 환자 1례에 대한 증례보고 (The Clinical Study on 1 Case of HNP Patient with Sequela of Epidural Block)

  • 강재희;장석근;임윤경;이현;이병렬
    • 대한한의학회지
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    • 제25권1호
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    • pp.213-219
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    • 2004
  • 1. 경막의 차단술 시행시 경막천자로 인해 두통, 이명, 항부강직감, 현운 등의 후유증이 발생할 수 있다. 2. 경막외 차단술 후유증의 증상들은 간신음허로 변증할 수 있다. 3. 경막외 차단술 후유증 동반한 유추간판탈출증 환자에게 음허변증에 기본하여 한방치료한 결과 후유증으로 인한 두통, 이명, 항부강직감 등이 소실되었고, 요통, 하지인통의 추간판탈출증상도 개선되었다.

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열복사에 의한 고체연료 점화 연구 (Ignition of a solid fuel by thermal radiation)

  • 김명효;백승욱
    • 대한기계학회논문집B
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    • 제22권3호
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    • pp.294-302
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    • 1998
  • Ignition characteristics of a vertical solid fuel plate with block have been investigated experimentally. For low radiant heat flux, ignition does not occur in a vertical solid fuel plate without block. In the case with the block on a vertical fuel plate, however, ignition can occur by increasing the residence time and the time to absorb the incident radiation flux by fuel vapor in gas phase. The ignition occurs below block and the point varies according to the block location and the block height. As the block height increases, the block locates at higher position, and the hot wall temperature increases, the ignition delay time decreases. Also as the initial temperature of fuel plate rises, the ignition delay time of the solid fuel plate decreases. The temperature distribution of solid fuel plate with block is nearly proportional to the radiant heat flux distribution. Therefore, the effect temperature by natural convection heat transfer is of the same order as that of inhibition of temperature increase by pyrolysis.

대형 멀티미디어 파일의 익명성 지원을 위한 수정 GNUnet (GNUnet improvement for anonymity supporting in large multimedia file)

  • 이윤진;이명훈;조인준
    • 인터넷정보학회논문지
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    • 제7권5호
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    • pp.71-79
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    • 2006
  • GNUnet은 파일의 익명성 지원을 위해 파일을 1KB블록크기로 분리하는 인코딩 방법을 채택하였고, 인코딩된 블록을 비구조적인 분산기법을 통해 피어들에게 분산시키고 있다. 하지만 이러한 인코딩 및 블록 분산 방안은 약 600$\sim$700MB의 대용량 멀티미디어 파일을 처리할 경우 첫째, 추가적으로 R블럭과 I블럭을 과도하게 요구하게 되어 약 4%의 저장공간을 낭비하는 문제를 지니고 있다. 둘째, 비구조적 브로드캐스팅 분산방법 때문에 네트워크 부하가 과도한 단점을 내포하고 있다. 본 논문에서는 이러한 문제점 해결을 위하여 인코딩 블록의 크기를 가변적으로 결정하는 방법과 구조적 위상을 통해 블록을 분산시키는 방안을 제안하였다. 제안 인코딩 방법은 추가 블록 생성을 1%이내로 최소화하였고, 분리된 블록의 분산을 위해 지정된 피어로 질의를 보내는 구조적 위상을 채택하여 블록 요청에서 발생하는 네트워크 부하를 감소시켰다.

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멀티캐스트 ATM망에서 ABT 블록스케쥴링을 이용한 UBR 트래픽 성능 개선에 관한 연구 (Study on Improvement of UBR Traffic Performance using ABT Block Scheduling in Multicast ATM Networks)

  • 임동규
    • 한국통신학회논문지
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    • 제25권10B호
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    • pp.1665-1674
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    • 2000
  • This paper treats the interworking of LAN-based networks like TCP over the ATM protocol stack in an ATM multicast session. Multicast connection will cause CIP since multicast group members form a connection tree by some tree methods and share the connected tree. The paper solve the CIP problem through a block-by-block transmission using ABT/IT method. ABT/IT RM cell is modified and block scheduling algorithm considering the traffic types is applied to each ATM switch using the enhanced RM cell. Block scheduling algorithm will avoid the indiscriminate discard of UBR traffic when congestion occurs and it can provide an efficient and fair service. The paper builds a block scheduler system and suggests the block scheduling algorithm for a multicast session in an ATM switch. UBR traffics arriving at the switch trough each VC is classified by the traffic type and stored at class buffer and thereafter indisciminately transmitted. When block scheduling algorithm is applied it will improve the UBR traffic performance such as end-to-end delay cell block loss ration etc. This paper evaluated the performance of block scheduling algorithm through the simulation using the C language and data structure.

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Dynamic analysis of water storage tank with rigid block at bottom

  • Adhikary, Ranjan;Mandal, Kalyan Kumar
    • Ocean Systems Engineering
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    • 제8권1호
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    • pp.57-77
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    • 2018
  • The present paper deals with the finite element analysis of water tanks with rigid baffle. Fluid is discretized by two dimensional eight-node isoparametric elements and the governing equation is simulated by pressure based formulation to reduce the degrees of freedom in the domain. Both free vibration and force vibration analysis are carried out for different sizes and positions of block at tank bottom. The fundamental frequency depends on block height and it reduces with the increase of block height. The variation of hydrodynamic pressure on tank walls not only depends of the exciting frequency but also on the size and position of rigid block at tank bottom. The hydrodynamic pressure has higher value when the exciting frequency is equal and lower than the fundamental frequency of the water in the tank. Similarly, the hydrodynamic pressure increases with the increase of width of the block for all exciting frequencies when the block is at the centre of tank. The left and right walls of tank have experienced different hydrodynamic pressure when the block is placed at off-centre. However, the increase in hydrodynamic pressure on nearest tank wall becomes insignificant after a certain value of the distance between the wall and the rigid block.