• 제목/요약/키워드: feed-forward

검색결과 535건 처리시간 0.022초

고속의 버스트 전송을 위한 새로운 피드포워드 타이밍 추정 기법 (A New FeedForward(FF) Timing Estimation Technique for High-Speed Transmission of Bursts)

  • 최윤석;조지훈;김응배;차균현
    • 한국통신학회논문지
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    • 제25권12A호
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    • pp.1774-1780
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    • 2000
  • 본 논문에서는 TDMA 방식의 고속의 버스트 데이터 전송에서 프리앰블의 오버샘플링 데이터 값을 이용한 새로운 피드포워드 타이밍 추정 기법을 제안한다. 제안된 추정 기법은 검출 오류 분산 값 (DEV : Detection Error Variance) 측면에서 기존의 여러 타이밍 추정기법과 MCRB (Modified Cramer-Rao Bound)와 비교되어 진다. 또한, 제안된 타이밍 추정 기법을 고정 샘플링 클럭과 타이밍 보정기로서 보간 필터를 이용한 심볼 동기 블록을 적용하여 이상적인 경우의 BER과 그 성능을 비교한 결과 이상적인 경우에 비해 성능 저하가 BER이 $10^{-3}$인 지점에서 최대 0.2dB 이내임을 확인하였다.

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비결합 전향 보상기를 갖는 선형다변수 시스템의 퍼지제어기 설계 (Fuzzy Controller Design of MIMO System with Decoupling Feedforward Compensator)

  • 송정화;정동근;김영철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 B
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    • pp.407-409
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    • 1998
  • In order to improve the tracking performance of $2{\times}2$ multivariable control systems, a fuzzy control algorithm with feedforward compensator is represented. The method consists in two steps. First, neglecting interconnections. one designs a fuzzy controller to each individual loop. In the second stage, low-order transfer functions of outputs to reference inputs are estimated. We propose a design method of the feed forward compensator based on the transfer functions. An illustrative example are shown.

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Prediction Partial Molar Heat Capacity at Infinite Dilution for Aqueous Solutions of Various Polar Aromatic Compounds over a Wide Range of Conditions Using Artificial Neural Networks

  • Habibi-Yangjeh, Aziz;Esmailian, Mahdi
    • Bulletin of the Korean Chemical Society
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    • 제28권9호
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    • pp.1477-1484
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    • 2007
  • Artificial neural networks (ANNs), for a first time, were successfully developed for the prediction partial molar heat capacity of aqueous solutions at infinite dilution for various polar aromatic compounds over wide range of temperatures (303.55-623.20 K) and pressures (0.1-30.2 MPa). Two three-layered feed forward ANNs with back-propagation of error were generated using three (the heat capacity in T = 303.55 K and P = 0.1 MPa, temperature and pressure) and six parameters (four theoretical descriptors, temperature and pressure) as inputs and its output is partial molar heat capacity at infinite dilution. It was found that properly selected and trained neural networks could fairly represent dependence of the heat capacity on the molecular descriptors, temperature and pressure. Mean percentage deviations (MPD) for prediction set by the models are 4.755 and 4.642, respectively.

고이득 외란 관측기에 기반한 입력 제약 조건이 있는 불확실한 선형 시스템의 강인 추종 제어 (Robust Tracking of Constrained Uncertain Linear Systems using a High-gain Disturbance Observer)

  • 윤문채;김정수;백주훈
    • 제어로봇시스템학회논문지
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    • 제22권6호
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    • pp.397-402
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    • 2016
  • This paper proposes a robust tracking control for constrained uncertain linear systems by combining a disturbance observer (DOB) and linear matrix inequality (LMI) based state feedback control. To this end, the state feedback control is designed for the nominal system and then a DOB based feed-forward control is added to reject uncertainties. In doing so, the DOB and state feedback controller are joined in a way that the combined control satisfies the input constraints and closed loop stability is guaranteed. Simulation results are provided to show that the proposed control scheme successfully stabilizes uncertain systems.

A 1.2-V 0.18-${\mu}m$ Sigma-Delta A/D Converter for 3G wireless Applications

  • Kim, Hyun-Joong;Jung, Tae-Sung;Yoo, Chang-sik
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.627-628
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    • 2006
  • A low-voltage switched-capacitor $2^{nd}$-order $\Sigma\Delta$ modulator using full feed-forward is introduced. It has two advantages: the unity signal transfer function and reduced signal swings inside the $\Sigma\Delta$ loop. These features greatly relax the DC gain and output swing requirements for Op-Amp in the low-voltage $\Sigma\Delta$ modulator. Implemented by a 0.18-${\mu}m$ CMOS technology, the $\Sigma\Delta$ modulator satisfies performance requirements for WCDMA and CDMA2000 standards.

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사전 정보를 이용한 다층신경망의 설계 (A Design Method for a New Multi-layer Neural Networks Incorporating Prior Knowledge)

  • 김병호;이지홍
    • 전자공학회논문지B
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    • 제30B권11호
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    • pp.56-65
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    • 1993
  • This paper presents the design consideration of the MFNNs(Multilayer Feed forward Neural Networks) based on the distribution of the given teching patterns. By extracting the feature points from the given teaching patterns, the structure of a network including the netowrk size and interconnection weights of a network is initialized. This network is trained based on the modified version of the EBP(Error Back Propagation) algorithm. As a result, the proposed method has the advantage of learning speed compared to the conventional learning of the MFNNs with randomly chosen initial weights. To show the effectiveness of the suggested approach, the simulation result on the approximation of a two demensional continuous function is shown.

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계통연계형 태양광발전 시스템의 제어기법 (Control Technique of a Utility Interactive Photovoltaic Generation System)

  • 김대균;전기영;함년근;이상집;오봉환;정춘병;김용주;한경희
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.54-56
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    • 2005
  • The paper proposes the solar photovoltaic power generation system method for photovoltaic system to solve the power shortage due the sudden power demand. So that supplied electric power to system at appearance during surplus electric power minute and unit moment link driving with common use system is available, digital PLL circuit system voltage through composition and phase of solar photovoltatic power generation system to do synchronization do. Feed forward controller was applied to get fast current response Solar cell that is changed by solar radiation always kept the maximum output when it used Step up chopper. The dynamic character had checked through simulation used Matlab Sumulink and confirmed through an experiment.

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Design and Implementation of an Active EMI Filter for Common-Mode Noise Reduction

  • Lee, Kuk-Hee;Kang, Byeong-Geuk;Choi, Yongoh;Chung, Se-Kyo;Won, Jae-Sun;Kim, Hee-Seung
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.1236-1243
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    • 2016
  • This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

On-Chip 학습기능을 가진 확률연산 펄스형 디지털 신경망의 구현 (Implementation of A Pulse-mode Digital Neural Network with On-chip Learning Using Stochastic Computation)

  • 위재우;이종호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2296-2298
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    • 1998
  • In this paper, an on-chip learning pulse-mode digital neural network with a massively parallel yet compact and flexible network architecture is suggested. Algebraic neural operations are replaced by stochastic processes using pseudo-random sequences and simple logic gates are used as basic computing elements. Using Back-propagation algorithm both feed-forward and learning phases are efficiently implemented with simple logical gates. RNG architecture using LFSR and barrel shifter are adopted to avoid some correlation between pulse trains. Suggested network is designed in digital circuit and its performance is verified by computer simulation.

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추진장치 조합시험을 위한 프로그램어블 다이나모메터 제어 (A Programmable-Dynamometer Control For Propulsin system combined Testing)

  • 김길동;이한민;오세찬;강승욱;이훈구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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    • pp.180-183
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    • 2005
  • A programmable dynamometer is the proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance. To verify a superiority of the proposed control algorithm, the analysis for a root locus of a conventional control method and the proposed one, and simulation and experiment is performed. Therefore we hope to be extended in industrial application.

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