• Title/Summary/Keyword: Block

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

  • Lee, Jae-Yik;Kim, Young-Jo;Shim, Bong-Sup;Lee, Hyun-Woo
    • Journal of Yeungnam Medical Science
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    • v.6 no.2
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    • pp.241-245
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    • 1989
  • Induction of A-V block by tachycardia is a well-known phenomenon. But there are few case reports of bradycardia-dependent A-V block. We report a case of bradycardia-dependent A-V block with review of literatures. This patient was a 52-year-old fe male who complained of dizziness and anterior chest discomfort. Electrocardiographic recording demonstrated complete A-V block. Monitor electrocardiographic recordings during sitting position and after atropine administration demonstrated decrease of degree of block from complete A-V block to first degree A-V block. The occurrence of complete A-V block for bradycardia during supine position suggests a phase 4-dependent block. After a permanent ventricular pacemaker was implanted, the patient recovered and was with out symptoms during 12 months follow up.

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

  • Choi, Hong Kyoon
    • Korean Journal of Materials Research
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    • v.29 no.12
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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.

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

  • 김재철;박종식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.11
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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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Postprocessing Method for Blocking Artifact Reduction Using Block Classification and Adaptive Filtering (블록 분류와 적응적 필터링을 이용한 후처리에서의 블록화 현상 제거 방법)

  • 이석환;권기구;김병주;이승진;권성근;이건일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.6A
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    • pp.592-601
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    • 2002
  • A postprocessing method for blocking artifact reduction in block coded images is presented. The proposed method consists of classification, adaptive inter-block filtering, and intra-block filtering. First, each block is classified as one of seven classes according to the characteristics of 8x8 DCT coefficients. Then each block boundary is faltered by adaptive inter-block filters, which use the block classes. Finally to the blocks which are classified as edge block classes, intra-block filtering is performed. Experimental tests produced that the proposed method gives better results than the convectional methods from both a subjective and an objective viewpoint.

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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    • v.9 no.1
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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.

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

  • 강재희;장석근;임윤경;이현;이병렬
    • The Journal of Korean Medicine
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    • v.25 no.1
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    • pp.213-219
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    • 2004
  • Objectives: This study is reported to evaluate the effect of oriental medical treatment in 1 caseof HNP patient with sequela of epidural block. Methods : We treated the patient by oriental medical conservative treatment, Who was diagnosed as the sequela of epidural block and admitted Daejeon University Cheonan oriental hospital from 9th November 2002 to 17th December 2002. Results & Conclusions: 1. It may occur headache, tinnitus, dizziness, neck stiffness from sequela of epidural block. 2. Sequela of epidural block can be demonstrated as deficiency of yin(陰虛). 3. After oriental medical conservative treatment, nothing symptom of sequela of epidural block(lumbago, leg pain) was improved but symptom of sequela of epidural block(headache, tinnitus, dizziness, neck stiffness) was disappeared and we consider that the oriental medical treatment baced on the concept of 'deficiency of yin(陰虛)' is effective in the caseof HNP patient with sequela of epidural block.

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

  • Kim, Myeong-Hyo;Baek, Seung-Uk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.3
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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.

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

  • Lee, Yoon-Jin;Lee, Myoung-Hoon;Jo, In-June
    • Journal of Internet Computing and Services
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    • v.7 no.5
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    • pp.71-79
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    • 2006
  • The GNUnet proposed a file encoding method by lKB block size to support anonymity of files and decentralizes encoded block to peers through unstructured model. but, the encoding and block decentralizing method with 600$\sim$700MB large multimedia file appeared two problems. First problem. it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructured model added network load by broadcasting decentralizing method. This paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation to 1% and network load by proposal structured model sending answer through dedicated peer to decentralize block.

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

  • 임동규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10B
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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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    • v.8 no.1
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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.