• Title/Summary/Keyword: communication density

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A study on phase transition of Hydrogel: (I)Volume Phase Transition of N-Isopropylacrylamide gel (수화겔의 상전이에 관한 연구: (I)폴리(N-이소프로필아크릴아미드)겔의 부피상전이)

  • Park, Sang-Bo;Min, Seong-Kee
    • Journal of the Korean Graphic Arts Communication Society
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    • v.21 no.1
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    • pp.11-20
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    • 2003
  • Equilibrium swelling curves of N-isopropyl acrylamide(NIPA) gel and its ionized copolymer gels were obtained as a function of temperature. Discontinuous volume changes of the gels were observed. Phase transition temperature was increased with the ionized counter parts of the gels. Equilibrium swelling of ionized copolymer gel cylinder was found to depend strongly on their diameters. Crosslinking density of NIPA gel was adjusted by increasing N,N'-methylenebisacrylamide(BIS). Phase transition temperature was increased with the crosslinking density.

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Effect of surface area of Lake Red C pigment and solvent contents in inks on the physical properties of printing inks (Lake Red C 안료의 표면적과 용매함량이 인쇄잉크의 물성에 미치는 영향)

  • 김종래
    • Journal of the Korean Graphic Arts Communication Society
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    • v.15 no.1
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    • pp.17-30
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    • 1997
  • In this work, we have investigated the printability such as print through and str-off of domestic newspapers. Nine kinds of domestic newspapers Hansol, Deahan, Sinho, Hanla and Sepung, were tested by IGT printability tester, and studied using maximum ink requirement method. We obtained the datum of printability parameters such as maximum ink requirment of paper Ymax, printing density D, print through, set-off and gloss. The results of this test showed that a choice of the fillers on the newspaper had an effect on print through, set-off and density of newspapers in the maximum ink transfer point.

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Implementation of Dual-Diagonal Quasi-cyclic LDPC(Low Density Parity Check) decoder for Efficient Encoder (효율적 부호를 고려한 Dual-Diagonal Quasi-cyclic LDPC(Low Density Parity Check) 복호기의 구현)

  • Byun, Yong-Ki;Kim, Jong-Tae
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2023-2024
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    • 2006
  • 1962년 Gallager에 의해 처음 제안된 LDPC 부호는 복호를 수행하는 부호방식으로 패리티 행렬(H)의 대부분이 0으로 구성되어 복호시에 적은 연산량을 요구하며, shannon의 한계에 도달하는 복호 능력으로, 차세대 통신의 주된 부호 방식으로 고려되고 있다. 하지만, LDPC는 부호화에 있어서 여타 다른 부호방식에 비해 복잡한 특성을 가지고 있으므로, 이를 개선하기 위한 부호방식의 적용이 필요하다. 본 논문에서는 효율 적인 부호화를 위하여 Dual-diagonal H parity행렬을 구성 하고, 쉽게 부호 길이를 확장 할 수 있는 Quasi-Cyclic 방식을 적용한 복호기를 구현하였다.

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Magnetic field Reduction characteristics of shielding wear for a worker by using AC Arc welder. (교류 아크용접기를 사용하는 작업자의 차폐복 자계저감 특성검토)

  • Park, Jun-Hyeong;Min, Suk-Won
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1343-1344
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    • 2008
  • This paper analyses current densities induced inside a worker using AC arc welder when he wears a protective cloth. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 1[cm], 15[cm], 20[cm] far from a power cable of AC arc welder. As results of study, we find a maximum current density induced in all organs may be lower than 10[$mA/cm^2$] if he wears a protective cloth. We also know high permeability materials can lower current density more than high conductivity materials.

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Rate-Compatible LDPC Codes Based on the PEG Algorithm for Relay Communication Systems

  • Zhou, Yangzhao;Jiang, Xueqin;Lee, Moon Ho
    • Journal of Communications and Networks
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    • v.17 no.4
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    • pp.346-350
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    • 2015
  • It is known that the progressive edge-growth (PEG) algorithm can be used to construct low-density parity-check (LDPC) codes at finite code lengths with large girths through the establishment of edges between variable and check nodes in an edge-by-edge manner. In [1], the authors derived a class of LDPC codes for relay communication systems by extending the full-diversity root-LDPC code. However, the submatrices of the parity-check matrix H corresponding to this code were constructed separately; thus, the girth of H was not optimized. To solve this problem, this paper proposes a modified PEG algorithm for use in the design of large girth and full-diversity LDPC codes. Simulation results indicated that the LDPC codes constructed using the modified PEG algorithm exhibited a more favorable frame error rate performance than did codes proposed in [1] over block-fading channels.

Image Recognition by Learning Multi-Valued Logic Neural Network

  • Kim, Doo-Ywan;Chung, Hwan-Mook
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.3
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    • pp.215-220
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    • 2002
  • This paper proposes a method to apply the Backpropagation(BP) algorithm of MVL(Multi-Valued Logic) Neural Network to pattern recognition. It extracts the property of an object density about an original pattern necessary for pattern processing and makes the property of the object density mapped to MVL. In addition, because it team the pattern by using multiple valued logic, it can reduce time f3r pattern and space fer memory to a minimum. There is, however, a demerit that existed MVL cannot adapt the change of circumstance. Through changing input into MVL function, not direct input of an existed Multiple pattern, and making it each variable loam by neural network after calculating each variable into liter function. Error has been reduced and convergence speed has become fast.

A Study on the Printability of Printing Paper according to the Changing of Calendering Condition (Calendering 조건 변화에 따른 인쇄용지의 인쇄적성에 관한 연구)

  • Kwon, Young-Jong;Youn, Jong-Tae;Ha, Young-Baeck
    • Journal of the Korean Graphic Arts Communication Society
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    • v.23 no.2
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    • pp.25-43
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    • 2005
  • Generally, machine calendering are used change of paper surface properties. During machine calendering, dry paper passes between the rolls under pressure, thereby improving the surface smoothness and gloss. These improvements make the paper better suited for printing and decreasing problems during the printing, such as delayed dry and set-off. Then we investigated newspaper properties by the changing of machine calendering condition, and relationship printability. Properties of each samples were examined in accordance with KS and TAPPI standard test method i.e, basic weight, bulk density, thickness, porosity, opacity, brightness, smoothness and roughness. IGT printability tester was used to obtain ink requirement of newspaper, printed density and set-off. Results of in this study, we have proposed the optimizes range of newspaper calendering condition. Useful optimize calendering condition was pressure 55 kN/m, temperature $130^{\circ}C$.

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Leakage Flux Distribution in the Simulated Environment

  • Kim, Chung-Hyeok;Kim, Tag-Yong;Oh, Yong-Cheul
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.401-405
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    • 2012
  • Current research about voltage leakage involves investigation of the effects of leaked voltage and current on humans through simulated environments and dummies. Electrocution results from leaked current when electricity flows through the body as a result of potential difference. Research that analyzes actual electrocution is insufficient because of the danger from leaked voltage present in the leakage area. This thesis analyzes magnetic flux density from current around a leak to investigate the distribution of current. The authors used a simulated environment to investigate electrocution accidents that frequently occur during floods through leakage along metal surfaces, and evaluated the distribution of leaked magnetic flux.

Improved Reliability-Based Iterative Decoding of LDPC Codes Based on Dynamic Threshold

  • Ma, Zhuo;Du, Shuanyi
    • ETRI Journal
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    • v.37 no.4
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    • pp.736-742
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    • 2015
  • A serial concatenated decoding algorithm with dynamic threshold is proposed for low-density parity-check codes with short and medium code lengths. The proposed approach uses a dynamic threshold to select a decoding result from belief propagation decoding and order statistic decoding, which improves the performance of the decoder at a negligible cost. Simulation results show that, under a high SNR region, the proposed concatenated decoder performs better than a serial concatenated decoder without threshold with an Eb/N0 gain of above 0.1 dB.

Temperature dependency of dc Characteristics for HEMTs (온도변화에 따른 HEMT의 DC 특성 연구)

  • 김진욱;황광철;이동균;안형근;한득영
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.29-32
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    • 2000
  • In this paper, an analytical model for I-V characteristics of a HEMTs is Proposed. The developed model takes into account the temperature dependence of drain current. In high-speed ICs for optical communication systems and mobile communication systems, temperature variation affects performance; for example the gain, efficiency in analog circuits and the delay time, power consumption and noise mrgin in digital circuits. To design such a circuit taking into account the temperature dependence of the current-voltage characteristic is indispensible. This model based on the analytical relation between surface carrier density and Fermi potential including temperature dependent coefficients.

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