• Title/Summary/Keyword: SA channel

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Hybrid of SA and CG Methods for Designing the Ka-Band Group-Delay Equalized Filter (Ka-대역 군지연-등화 여파기용 SA 기법과 CG 기법의 하이브리드 설계 기법)

  • Kahng, Sungtek
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.8
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    • pp.775-780
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    • 2004
  • This paper describes the realization of the Ka-band group-delay equalized filter desisted with the help of a new hybrid method of Simulated Annealing(SA) and Conjugate Gradient(CG), to be employed by the multi-channel Input Multiplexer for a satellite use, each channel of which comprises a channel filter and a group-delay equalizer. The SA and CG find circuit parameters of an 8th order elliptic function filter and a 2-pole equalizer, respectively. Measurement results demonstrate that the performances of the designed component meet the specifications, and validate the design methods.

Channel Function of TRPML1 Prompts Lipolysis in Mature Adipocytes

  • Kim, Mi Seong;Kim, Min Seuk
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.23-27
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    • 2018
  • Increased intracellular levels of $Ca^{2+}$ are generally thought to negatively regulate lipolysis in mature adipocytes, whereas store-operated $Ca^{2+}$ entry was recently reported to facilitate lipolysis and attenuate lipotoxicity by inducing lipophagy. Transient receptor potential mucolipin1 (TRPML1), a $Ca^{2+}$-permeable non-selective cation channel, is mainly expressed on the lysosomal membrane and plays key roles in lysosomal homeostasis and membrane trafficking. However, the roles of TRPML1 in lipolysis remains unclear. In this study, we examined whether the channel function of TRPML1 induces lipolysis in mature adipocytes. We found that treatment of mature adipocytes with ML-SA1, a specific agonist of TRPML1, solely upregulated extracellular glycerol release, but not to the same extent as isoproterenol. In addition, knockdown of TRPML1 in mature adipocytes significantly reduced autophagic flux, regardless of ML-SA1 treatment. Our findings demonstrate that the channel function of TRPML1 partially contributes to lipid metabolism and autophagic membrane trafficking, suggesting that TRPML1, particularly the channel function of TRPML1, is as therapeutic target molecule for treating obesity.

A Study on Welding Distortion of Channel I Butt SA Weld using FE Analysis (유한요소해석을 이용한 Channel I butt SA 용접부 변형 해석에 관한 연구)

  • Shin, Dae-Hee;Shin, Sang-Beam;Lee, Joo-Sung
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.189-192
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    • 2006
  • The purpose of this study is to evaluate the welding distortion at the channel I butt SA weldment. In order to do it, the heat input model for the weldment was defined as combined heat source with the surface heat flux of gaussian mode and volume heat source uniformly distributed within weld groove on the basis of comparing the shapes of molten pool and temperature distribution obtained by FEA and experiment. The arc efficiency of SA welding for 2 dimensional FE analysis was determined as 0.85. The results of welding distortions at the weldment obtained by FEA and heat input conditions proposed have a good agreement with those obtained by experiment. Based on the results, it was suggested that the proper heat input model should be required to evaluate the welding distortion for weldment.

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A study on improvement of steady-state peformance and convergence rate in an adaptive noise canceller (적응잡음제거기의 정상상태 성능 및 수렴율 향상에 관한 연구)

  • 배종갑;김창기;박장식;손경식
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.4
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    • pp.42-49
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    • 1997
  • A conventional adaptive noise canceller (ANC) using LMS algorithm suffers from the misadjustment of adaptive filter weights due to the gradient-estimate noise by input speech signal at steady state. In this paper, an ANC is proposed which uses the combination of VSLMS (variable step size LMS) and SA (sign algorithm) to improve steady state performance and convergence rate. SA algorithm is applied in speech region to prevent the weights from perturbing by output speech of ANC and VSLMS algorithm is applied to improve convergence rate and channel tracking ability in silence region and adaptive transient region. In compute rsimulation, the performance of the proposed VSLMS-SA combination algorithm is much better than LMS algorithm and the algorithm, recently proposed by greenberg, with adaptation step-size parameter determine dby sum method in convergence rate, channel tracking and steady state performance.

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Involvement of calcium and calmodulin in the acquisition of SA-induced thermotolerance in cucumber seedlings

  • Jung, -You-Jin;Jung, -Sang-Duk;Kim, -Tae-Yun;Hong, -Jung-Hee
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2002.05b
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    • pp.471-474
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    • 2002
  • SA treatment significantly increased thermotolerance In cucumber seedlings. Pretreatment of seeds with $CaCl_2$ solution enhanced the SA- induced thermotolerance. On the contrary, pretreatment with the $Ca^{2+}$ chelator EGTA lowered this SA-induced thermotolerance. In addition, pretreatment with $Ca^{2+}$ channel blocker verapamil also weakened the SA-induced thermotolerance. However, the calmodulin antagonist chlorpromazine(CPZ) had little effect on the SA-induced thermotolerance. Measurement of activity of the antioxidant enzyme APX and the level of lipid peroxidation (in term of MDA) indicated that heat stress induced an oxidative stress in cucumber seedlings. SA treatment induced higher activities of APX and a lower level of lipid peroxidation. $Ca^{2+}$ pretreatment further enhanced the SA-induced increase in APX activity and lowered the heat stress-induced lipid peroxidation, but EGTA pretreatment had a contrary effect. These results suggest that $Ca^{2+}$ and calmodulin may be involved In the acquisition of the SA-induced thermotolerance; antioxidant enzyme system take part in the final generation of the SA-induced thermotolerance.

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A Study on Blind Nonlinear Channel Equalization using Modified Fuzzy C-Means (개선된 퍼지 클러스터 알고리즘을 이용한 블라인드 비선형 채널등화에 관한 연구)

  • Park, Sung-Dae;Han, Soo-Whan
    • Journal of Korea Multimedia Society
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    • v.10 no.10
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    • pp.1284-1294
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    • 2007
  • In this paper, a blind nonlinear channel equalization is implemented by using a Modified Fuzzy C-Means (MFCM) algorithm. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.

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Performance Improvement on Fuzzy C-Means Algorithm for Nonlinear Blind Channel Equalization (비선형 블라인드 채널등화를 위한 퍼지 클러스터 알고리즘의 성능개선)

  • Park, Seong-Dae;Han, Su-Hwan
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2007.05a
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    • pp.382-388
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    • 2007
  • In this paper, a modified Fuzzy C-Means (MFCM) algorithm is presented for nonlinear blind channel equalization. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.

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Lattice Reduction Aided Preceding Based on Seysen's Algorithm for Multiuser MIMO Systems (다중 사용자 MIMO 시스템을 위한 Seysen 알고리즘 기반 Lattice Reduction Aided 프리코팅)

  • An, Hong-Sun;Mohaisen, Manar;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.9C
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    • pp.915-921
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    • 2009
  • Lenstra-Lenstra-Lovasz (LLL) algorithm, which is one of the lattice reduction (LR) techniques, has been extensively used to obtain better bases of the channel matrix. In this paper, we jointly apply Seysen's lattice reduction Algorithm (SA), instead of LLL, with the conventional linear precoding algorithms. Since SA obtains more orthogonal lattice bases compared to those obtained by LLL, lattice reduction aided (LRA) precoding based on SA algorithm outperforms the LRA precoding with LLL. Simulation results demonstrate that a gain of 0.5dB at target BER of $10^{-5}$ is achieved when SA is used instead of LLL or the LR stage.

Blind Nonlinear Channel Equalization by Performance Improvement on MFCM (MFCM의 성능개선을 통한 블라인드 비선형 채널 등화)

  • Park, Sung-Dae;Woo, Young-Woon;Han, Soo-Whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.11
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    • pp.2158-2165
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    • 2007
  • In this paper, a Modified Fuzzy C-Means algorithm with Gaussian Weights(MFCM_GW) is presented for nonlinear blind channel equalization. The proposed algorithm searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function and Gaussian weighted partition matrix instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function(RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with those of a simplex genetic algorithm(GA), a hybrid genetic algorithm(GA merged with simulated annealing(SA): GASA), and a previously developed version of MFCM. It is shown that a relatively high accuracy and fast search speed has been achieved.