• Title/Summary/Keyword: CMA

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Performance of the MMSE Receiver Front-ended by CMA Array in the Mult-path Faded CDMA Forward Link.

  • Lee, Yun-Soo;Chinn, Yong-Oak
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.328-332
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    • 2007
  • The structure of MMSE receiver frontended by CMA array working in CDMA forward link is proposed. By using the despreaded pilot signal of forward link as a reference signal, CMA array can capture multi-path signals securely even in severely faded mobile channel. The remaining MAl (Multiple Access Interference) is cancelled by the cascaded MMSE receiver. Through computer simulation, it is proved that the proposed system shows much better BER performance than any other systems. As a mobile based spatio-temporal receiver, the proposed system also reduces implemental cost and complexity by adopting the simplest algorithm for its spatial and temporal domain processing.

Chromosomal Microarray Testing in 42 Korean Patients with Unexplained Developmental Delay, Intellectual Disability, Autism Spectrum Disorders, and Multiple Congenital Anomalies

  • Lee, Sun Ho;Song, Wung Joo
    • Genomics & Informatics
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    • v.15 no.3
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    • pp.82-86
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    • 2017
  • Chromosomal microarray (CMA) is a high-resolution, high-throughput method of identifying submicroscopic genomic copy number variations (CNVs). CMA has been established as the first-line diagnostic test for individuals with developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), and multiple congenital anomalies (MCAs). CMA analysis was performed in 42 Korean patients who had been diagnosed with unexplained DD, ID, ASDs, and MCAs. Clinically relevant CNVs were discovered in 28 patients. Variants of unknown significance were detected in 13 patients. The diagnostic yield was high (66.7%). CMA is a superior diagnostic tool compared with conventional karyotyping and fluorescent in situ hybridization.

A Study on Blind Multiuser Detection using the Constant Modulus Algorithm for DS-CDMA Systems (DS-CDMA 시스템 환경에서 Constant Modulus 알고리즘을 이용한 블라인드 다중사용자 검출에 관한 연구)

  • 김대규;우대호;변윤식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.10B
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    • pp.2004-2010
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    • 1999
  • This paper presents the blind multiuser detector using the constant modulus algorithm(CMA) to solve the near-far problem in DS-CDMA systems. The convergence property of the detector is compared with the conventional MOE(minimum output energy) detector by means of SIR(signal-to-interference ratio). The MOE detector needs both the spreading code of the users and the timing information, while proposed methods needs only information about the spreading code of users Simulation results show that the CMA-based detector is superior to the conventional blind MOE multiuser detector. For this, the BER performance was tested using different values of SNR and near-far ratio. The SIR is also investigated for different number of users in AWGN and Rayleigh fading channels. We have observed that the proposed blind multiuser detector performs better than conventional MOE multiuser detector.

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A Study on Adaptive Interference Cancellation System of RF Repeater Using the Grouped Constant-Modulus Algorithm (그룹화 CMA 알고리즘을 이용한 RF 중계기의 적응 간섭 제거 시스템(Adaptive Interference Cancellation System)에 관한 연구)

  • Han, Yong-Sik;Yang, Woon-Geun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.9
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    • pp.1058-1064
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    • 2008
  • In this paper, we proposed a new hybrid interference canceller using the adaptive filter with Grouped CMA(Constant Modulus Algorithm)-LMS(Least Mean Square) algorithm in the RF(Radio Frequency) repeater. The feedback signal generated from transmitter antenna to receiver antenna reduces the performance of the receiver system. The proposed interference canceller has better channel adaptive performance and a lower MSE(Mean Square Error) than conventional structure because it uses the cancellation method of Grouped CMA algorithm. This structure reduces the number of iterations fur the same MSE performance and hardware complexity compared to conventional nonlinear interference canceller. Namely, MSE values of the proposed algorithm were lower than those of LMS algorithm by 2.5 dB and 4 dB according to step sizes. And the proposed algorithm showed fast speed of convergence and similar MSE performance compared to VSS(Variable Step Size)-LMS algorithm.

A Study on Channel Equalization in Channels for Wireless Communication System (무선통신 시스템의 채널 환경에서 채널 등화에 관한 연구)

  • Kim, Dong-Ok
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.7 no.1
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    • pp.15-22
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    • 2007
  • The third generation mobile communications system requiring the reliable multimedia data transmission has provided with the reliable voice, data and video services over the variable propagation environment. However the broadband wireless multiple access technologies cause Inter Symbol Interference(ISI) or Multiple Access Interference(MAI) to degrade the performance of CDMA(Code Division Multiple Access) system. Constant Modulus Algorithm which is frequently used as the adaptive blind equalizers to remove the interfering signal has ill-convergence phenomenon without proper initialization. In this paper, new blind equalization method based on conventional CMA is proposed to improve the channel efficiency, and through computer simulation this is tested over the time varying fading environment of mobile communication system. consequently, new blind equalization method into concatenated Kalman filter with CMA is verified better than conventional CMA through adopting minimum mean square errors and eye- pattern obtained from algorithm are compared.

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Ebb-and-Flow of Macroautophagy and Chaperone-Mediated Autophagy in Raji Cells Induced by Starvation and Arsenic Trioxide

  • Li, Cai-Li;Wei, Hu-Lai;Chen, Jing;Wang, Bei;Xie, Bei;Fan, Lin-Lan;Li, Lin-Jing
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5715-5719
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    • 2014
  • Autophagy is crucial in the maintenance of homeostasis and regenerated energy of mammalian cells. Macroautophagy and chaperone-mediated autophagy(CMA) are the two best-identified pathways. Recent research has found that in normal cells, decline of macroautophagy is appropriately parallel with activation of CMA. However, whether it is also true in cancer cells has been poorly studied. Here we focused on cross-talk and conversion between macroautophagy and CMA in cultured Burkitt lymphoma Raji cells when facing serum deprivation and exposure to a toxic compound, arsenic trioxide. The results showed that both macroautophagy and CMA were activated sequentially instead of simultaneously in starvation-induced Raji cells, and macroautophagy was quickly activated and peaked during the first hours of nutrition deprivation, and then gradually decreased to near baseline. With nutrient deprivation persisted, CMA progressively increased along with the decline of macroautophagy. On the other hand, in arsenic trioxide-treated Raji cells, macroautophagy activity was also significantly increased, but CMA activity was not rapidly enhanced until macroautophagy was inhibited by 3-methyladenine, an inhibitor. Together, we conclude that cancer cells exhibit differential responses to diverse stressor-induced damage by autophagy. The sequential switch of the first-aider macroautophagy to the homeostasis-stabilizer CMA, whether active or passive, might be conducive to the adaption of cancer cells to miscellaneous intracellular or extracellular stressors. These findings must be helpful to understand the characteristics, compensatory mechanisms and answer modes of different autophagic pathways in cancer cells, which might be very important and promising to the development of potential targeting interventions for cancer therapies via regulation of autophagic pathways.

Sorption and Leaching Characteristics of Diesel-Contaminated Soils Treated by Cold Mix Asphalt (Cold Mix Asphalt로 처리한 디젤 오염 토양의 흡착 및 용출특성)

  • Seo Jin-Kwon;Hwang Inseong;Park Joo-Yang
    • Journal of Soil and Groundwater Environment
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    • v.9 no.4
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    • pp.24-31
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    • 2004
  • A cold mix asphalt (CMA) treatment process was proposed as a tool to recycle soils contaminated with petroleum hydrocarbons. Experimental studies were conducted to characterize performances of the CMA process in treating soils contaminated with diesel or diesel compounds. From the screening experiments, it was found that performances of five types of asphalt emulsions that contained a cationic or an anionic or a nonionic surfactant were not substantially different. In consideration of higher affinity for soils and higher sorption coefficients obtained, an emulsion containing Lauryl Dimethyl Benzyl Ammonium Chloride (LDBAC) was selected as a promising asphalt emulsion for treating diesel-contaminated soils. When the asphalt emulsion LDBAC was applied to treat three compounds that originated from diesel, the removal efficiencies obtained in the order of decreasing efficiencies were as follows: docosane > pentadecane > undecane. Leaching experiments on the specimen formulated by the emulsion LDBAC found that the selected treatment method could treat soils with diesel concentrations as high as 10,000 mg/kg. Leaching of the diesel from the specimen was controlled by diffusion for the first four days and then leaching rate diminished substantially. The latter behavior was characterized as depletion, which represents that the contaminant released amounts to more than $50\%$ of the total amount of the contaminant that can be leached. The amounts of three diesel compounds leached from the specimen in the order of decreasing amount were undecane, pentadecane, and docosane. The curing of the soil contaminated with pentadecane was relatively slow.

Interference Cancellation Methods using the CMF(Constant Modulus Fourth) Algorithm for WCDMA RF Repeater (WCDMA 무선 중계기에서 CMF 알고리즘을 이용한 간섭 제거 방식)

  • Han, Yong-Sik;Yang, Woon-Geun
    • Journal of IKEEE
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    • v.15 no.4
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    • pp.293-298
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    • 2011
  • In the paper, we propose a new CMF(Constant Modulus Fourth) algorithm for WCDMA(Wideband Code Multiple Access) RF(Radio Frequency) Repeater. CMF algorithm is proposed by modifying the CMA(Constant Modulus Algorithm) algorithm and improved performances are achieved by properly adjusting step size values. The steady state MSE(Mean Square Error) performance of the proposed CMF algorithm with step size of 0.35 is about 4dB better than that of the conventional CMA algorithm. And the proposed CMF algorithm requires 400~1100 less iterations than the LMS(Least Mean Square) and NLMS(Normalized Least Mean Square) algorithms at MSE of -25dB.

Interference Cancellation System in Repeater Using Adaptive algorithm with step sizes (스텝사이즈에 따른 적응 알고리즘을 이용한 간섭제거 중계기)

  • Han, Yong-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.5
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    • pp.549-554
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    • 2014
  • In the paper, we propose a new Signed LMS(Least Mean Square) algorithm for ICS(Interference Cancellation System). The proposed Signed LMS algorithm improved performances by adjusting step size values. At the convergence of 1000 iteration state, the MSE(Mean Square Error) performance of the proposed Signed LMS algorithm with step size of 0.067 is about 3 ~ 18 dB better than the conventional LMS, CMA algorithm. And the proposed Signed LMS algorithm requires 500 ~ 4000 less iterations than the and LMS and CMA algorithms at MSE of -25dB.

A New Blind Equalization Algorithm with A Stop-and-Go Flag (Stop-and-Go 플래그를 가지는 새로운 블라인드 등화 알고리즘)

  • Jeong, Young-Hwa
    • The Journal of Information Technology
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    • v.8 no.3
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    • pp.105-115
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    • 2005
  • The CMA and MMA blind equalization algorithm has the inevitable large residual error caused by mismatching between the symbol constellation at a steady state after convergence. Stop-and-Go algorithm has a very superior residual error characteristics at a steady state but a relatively slow convergence characteristics. In this paper, we propose a SAG-Flagged MMA as a new adaptive blind equalization algorithm with a Stop-and-Go flag which follows a flagged MMA in update scheme of tap weights as appling the flag obtaining from Stop-and-Go algorithm to MMA. Using computer simulation, it is confirmed that the proposed algorithm has an enhancing performance from the viewpoint of residual ISI, residual error and convergence speed in comparison with MMA and Stop-and-Go algorithm. Algorithm has a new error function using the decided original constellation instead of the reduced constellation. By computer simulation, it is confirmed that the proposed algorithm has the performance superiority in terms of residual ISI and convergence speed compared with the adaptive blind equalization algorithm of CMA family, Constant Modulus Algorithm with Carrier Phase Recovery and Modified CMA(MCMA).

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