• Title/Summary/Keyword: Complex channel

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The research of the way to gain domestic and foreign market economy force of whitening cosmetics (미백화장품 국내외 시장경쟁력 확보방안 연구)

  • Park, Joon-su;kim, heung-gi
    • International Area Studies Review
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    • v.21 no.2
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    • pp.121-141
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    • 2017
  • The world whitening cosmetics market is fast being taken in 'complex functional cosmetics' including complex function. And highly functional cosmetics market that call cosmeceutical market is growing up with highly functional cosmetics market. In addition, natural cosmetics market including whitening function is growing up in the world in complex functional cosmetics. Distribution channel of the world functional cosmetics is digital communication through beauty and digital. Global companies are adding relationship in new space between customer and brand. So worldwide change phenomenon of whitening cosmetics distribution channel will suggest importance that it should be able to communication with customer in non-traditional space. Domestic whitening cosmetics market is decreasing to reference compound annual growth rate -3.61%. While complex type market is increasing to annual growth rate 33.28%. Since 2008, domestic whitening cosmetics market was changed in distribution channel of center of traditional door-to-door sales. Especially, online channel is about 1/6 level of offline, but since 2014, year-on-year increase rate of online showed 27.1%. In the future, it is anticipated that ratio of online sales is above offline. Whitening cosmetics distribution is being changed, and online channel is growing up, so domestic companies will need tragedy targeting new whitening cosmetics distribution channel and traditional offline channel at the same time. If new company go into whitening cosmetics market, the new company will have to consider natural cosmetics in complex functional cosmetics than whitening cosmetics market. To secure domestic competitiveness whitening cosmetics market, securing differentiation of brand or pursuing change of distribution channel, and we need to seek a method that company and customer can forge communication in new space.

PDF-Distance Minimizing Blind Algorithm based on Delta Functions for Compensation for Complex-Channel Phase Distortions (복소 채널의 위상 왜곡 보상을 위한 델타함수 기반의 확률분포거리 최소화 블라인드 알고리듬)

  • Kim, Nam-Yong;Kang, Sung-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.12
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    • pp.5036-5041
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    • 2010
  • This paper introduces the complex-version of an Euclidean distance minimization algorithm based on a set of delta functions. The algorithm is analyzed to be able to compensate inherently the channel phase distortion caused by inferior complex channels. Also this algorithm has a relatively small size of Gaussian kernel compared to the conventional method of using a randomly generated symbol set. This characteristic implies that the information potential between desired symbol and output is higher so that the algorithm forces output more strongly to gather close to the desired symbol. Based on 16 QAM system and phase distorted complex-channel models, mean squared error (MSE) performance and concentration performance of output symbol points are evaluated. Simulation results show that the algorithm compensates channel phase distortion effectively in constellation performance and about 5 dB enhancement in steady state MSE performance.

QRS Complex Detection Algorithm Using M Channel Filter Banks (M 채널 필터 뱅크를 이용한 QRS complex 검출 알고리즘)

  • 김동석;전대근;이경중;윤형로
    • Journal of Biomedical Engineering Research
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    • v.21 no.2
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    • pp.165-174
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    • 2000
  • 본 논문에서는 M 채널 필터 뱅크를 이용하여 심전도 자동 진단 시스템에서 매우 중요한 파라미터로 사용되는 QRS complex 검출을 실시하였다. 제안된 알고리즘에서는 심전도 신호를 M개의 균일한 주파수 대역으로 분할(decomposition)하고, 분할된 서브밴드(subband) 신호들 중에서 QRS complex의 에너지 분포가 가장 많이 존재하는 5∼25Hz 영역의 서브밴드 신호들을 선택하여 feature를 계산함으로써 QRS complex 검출을 실시하였다. 제안된 알고리즘의 성능 비교를 위하여 MIT-BIH arrhythmia database를 사용하였으며, sensitivity는 99.82%, positive predictivity는 99.82, 평균 검출율은 99.67%로 기존의 알고리즘에 비해 높은 검출 성능을 나타내었다. 또한 polyphase representation을 이용하여 M 채널 필터 뱅크를 구현한 결과 연산 시간이 단추되어 실시간 검출이 가능함을 확인하였다.

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On the Complex-Valued Recursive Least Squares Escalator Algorithm with Reduced Computational Complexity

  • Kim, Nam-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.5C
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    • pp.521-526
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    • 2009
  • In this paper, a complex-valued recursive least squares escalator filter algorithm with reduced computational complexity for complex-valued signal processing applications is presented. The local tap weight of RLS-ESC algorithm is updated by incrementing its old value by an amount equal to the local estimation error times the local gain scalar, and for the gain scalar, the local input autocorrelation is calculated at the previous time. By deriving a new gain scalar that can be calculated by using the current local input autocorrelation, reduced computational complexity is accomplished. Compared with the computational complexity of the complex-valued version of RLS-ESC algorithm, the computational complexity of the proposed method can be reduced by 50% without performance degradation. The reduced computational complexity of the proposed algorithm is even less than that of the LMS-ESC. Simulation results for complex channel equalization in 64QAM modulation schemes demonstrate that the proposed algorithm has superior convergence and constellation performance.

An Accurate Estimation of Channel Loss Threshold Set for Optimal FEC Code Rate Decision (최적의 FEC 부호율 결정을 위한 정확한 채널손실 한계집합 추정기법)

  • Jung, Tae-Jun;Jeong, Yo-Won;Seo, Kwang-Deok
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.268-271
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    • 2014
  • Conventional forward error correction (FEC) code rate decision schemes using analytical source coding distortion model and channel-induced distortion model are usually complex, and require the typical process of model parameter training which involves potentially high computational complexity and implementation cost. To avoid the complex modeling procedure, we propose a simple but accurate joint source-channel distortion model to estimate channel loss threshold set for optimal FEC code rate decision.

Mathematical Modeling of VSB-Based Digital Television Systems

  • Kim, Hyoung-Nam;Lee, Yong-Tae;Kim, Seung-Won
    • ETRI Journal
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    • v.25 no.1
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    • pp.9-18
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    • 2003
  • We mathematically analyze the passband vestigial sideband (VSB) system for the Advanced Television Systems Committee (ATSC) digital television standard and present a baseband-equivalent VSB model. The obtained baseband VSB model is represented by convolution of the transmission signal (before modulation) and the baseband equivalent of the complex VSB channel. Due to the operation of the physical channel as an RF passband and the asymmetrical property of VSB modulation, it is necessary to use a complex model. However, the passband channel may be reduced to an equivalent baseband. We show how to apply standard channel model information such as delay, gain, and phase for multiple signal paths to compute both the channel frequency response with a given carrier frequency and the resulting demodulated impulse response. Simulation results illustrate that the baseband VSB model is equivalent to the passband VSB model.

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Implementation of 3-Dimensional Cooling Channel in Injection Mold Using RT Technology (RT 기술을 이용한 사출금형의 3 차원 냉각 채널 구현)

  • Kim J.D.;Hong S.K.;Lee K.H.;Kim M.A.;Lee D.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.199-200
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    • 2006
  • It will not be an exaggeration to say that one of the most important features of RT (Rapid Tooling) technology is to easy manufacturing complex shape of cooling channel in injection mold. That is, RT technology is hardly influenced complex shape of tool, Therefore, mold designer can optimize the position and shape of cooling channel whatever they want. In this study, we optimized cooling channel through CAE analysis to solve the problem; prototype-connector-mold applied conventional cooling channel, locally warped by internal stress: The effect of three-dimensional cooling channel was supported by simulation result. But it is impossible to produce injection mold applied three-dimensional cooling channel through machining operation. Therefore, we produced the prototype-connector-mold with three-dimensional cooling channel using Direct Metal Laser Sintering (DMLS) process, and get good-quality prototype-connector without warpage.

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Robust design of springback in U-channel forming using complex method (콤플렉스법을 이용한 U-채널 성형의 스프링백 강건 설계)

  • Yin, Jeong-Je;Kim, Kyung-Mo;Park, Jong-Cheon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.1
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    • pp.117-125
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    • 2013
  • Variations of springback in stamped parts are induced by the uncontrollable noises including the variation of incoming material properties, lubrication and other forming process parameters. Reduction of springback variation is very important during springback compensation processes on stamping dies and assembly processes. To reduce the variation of springback, a robust optimization methodology which uses complex method combined with orthogonal array is proposed. The proposed method is applied to the robust design of U-channel die for the reduction of side wall curl. It is shown that the drawbead and die radius of U-channel draw die can be effectively optimized by the proposed method.

3 Dimensional Flow Analysis of Small Regenerative Pump (소형 재생펌프의 3차원 성능 해석에 관한 연구)

  • Kang, Shin-Hyoung;Lim, Hyung-Soo;Ryu, Su-Hyun;Shim, Chang-Yeul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1600-1607
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    • 2004
  • Performance of a regenerative pump is evaluated based on the calculated through flows using the CFX-TASCflow code. Flow calculations are performed in one vane to vane space of the impeller and side channel. The flow is very complex three dimensional with a strong radial vortex due to centrifugal force and an axial vortex due to re-circulating flow between the impeller and the side channel. Momentum exchange on the plane between the impeller and the side channel are evaluated to estimate design parameters and viscous losses in the pump. The present study contributes to showing the capability of flow simulation of complex flow in the regenerative pump by comparing the calculated performance with the measured value.

Electrokinetic flow and electroviscous effect in a charged slit-like microfluidic channel with nonlinear Poisson-Boltzmann field

  • Chun, Myung-Suk;Kwak, Hyun-Wook
    • Korea-Australia Rheology Journal
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    • v.15 no.2
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    • pp.83-90
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    • 2003
  • In cases of the microfluidic channel, the electrokinetic influence on the transport behavior can be found. The externally applied body force originated from the electrostatic interaction between the nonlinear Poisson-Boltzmann field and the flow-induced electrical field is applied in the equation of motion. The electrostatic potential profile is computed a priori by applying the finite difference scheme, and an analytical solution to the Navier-Stokes equation of motion for slit-like microchannel is obtained via the Green's function. An explicit analytical expression for the induced electrokinetic potential is derived as functions of relevant physicochemical parameters. The effects of the electric double layer, the zeta potential of the solid surface, and the charge condition of the channel wall on the velocity profile as well as the electroviscous behavior are examined. With increases in either electric double layer or zeta potential, the average fluid velocity in the channel of same charge is entirely reduced, whereas the electroviscous effect becomes stronger. We observed an opposite behavior in the channel of opposite charge, where the attractive electrostatic interactions are presented.