• Title/Summary/Keyword: scaling factor

Search Result 451, Processing Time 0.032 seconds

A Performance Variation by Scaling Factor in NM-MMA Adaptive Equalization Algorithm (NM-MMA 적응 등화 알고리즘에서 Scaling Factor에 의한 성능 변화)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.18 no.2
    • /
    • pp.105-110
    • /
    • 2018
  • This paper compare the adaptive equalization performance of NM-MMA (Novel Mixed-MMA) algorithm which using the mixed const function by scaling factor values. The mixed cost function of NM-MMA composed of the appropriate weighted addition of gradient vector in the MMA and SE-MMA cost function, and updating the tap coefficient based on these function, it is possible to improve the convergence speed and MSE value of current algorithm. The computer simulation was performed in the same channel, step size, SNR environment by changing the scaling factor, and its performance were compared appling the equalizer output constellation, residual isi, MD, MSE, SER. As a result of computer simulation, the residual values of performance index were reduced in case of the scaling factor of MMA cost function was greater than the scaling factor of SE-MMA. and the convergence speed was improved in case of the scaling factor of SE-MMA was greater than the MMA.

A Study on the Analysis of Scaling Failure Cause in L-Shoulder Concrete Structure (L형측구 콘크리트 구조물의 표면박리파손 원인분석에 관한 연구)

  • Jeon, Sung Il;Nam, Jeong Hee;Ahn, Sang Hyeok;An, Ji Hwan
    • International Journal of Highway Engineering
    • /
    • v.16 no.6
    • /
    • pp.27-37
    • /
    • 2014
  • PURPOSES : The purpose of this study is to verify the causes of surface scaling at L-shoulder concrete structure. METHODS : From the literature reviews, mechanisms of frost damage were studied and material properties including strength, air void, spacing factor and scaling resistance of L-shoulder concrete structure were analyzed using core specimens taken by real fields. RESULTS : The spacing factor of air void has relatively high correlation of surface conditions : lower spacing factor at good surfacing condition and vice versa. If the compressive strength is high, even thought spacing factor does not reach the threshold value of reasonable durability, the surface scaling resistance shows higher value. Based on these test results, the compressive strength also provide positive effect on the surface scaling resistance. CONCLUSIONS : The main causes of surface scaling of L-shoulder could be summarized as unsuitable aid void amount and poor quality of air void structure. Secondly, although the compressive strength is not the governing factor of durability, but it shows the positive effect on the surface scaling resistance.

Fuzzy Control Method By Automatic Scaling Factor Tuning (자동 양자이득 조정에 의한 퍼지 제어방식)

  • 강성호;임중규;엄기환
    • Proceedings of the IEEK Conference
    • /
    • 2003.07c
    • /
    • pp.2807-2810
    • /
    • 2003
  • In this paper, we propose a fuzzy control method for improving the control performance by automatically tuning the scaling factor. The proposed method is that automatically tune the input scaling factor and the output scaling factor of fuzzy logic system through neural network. Used neural network is ADALINE (ADAptive Linear NEron) neural network with delayed input. ADALINE neural network has simple construct, superior learning capacity and small computation time. In order to verify the effectiveness of the proposed control method, we performed simulation. The results showed that the proposed control method improves considerably on the environment of the disturbance.

  • PDF

Position-type fuzzy controller using the accumulated error scaling factor (누적오차 조정계수를 이용한 위치형 퍼지제어기)

  • 김동하;전해진;최봉열
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.177-177
    • /
    • 2000
  • In this paper, we propose a two-input two-output fuzzy controller to improve the performance of transient response and to eliminate the steady state error. The outputs of this controller are the control input calculated by position-type fuzzy controller and the accumulated error scaling factor. Here, the accumulated error scaling factor is adjusted on-line by fuzzy rules according to the current trend of the controlled process. To show the usefulness of the proposed controller, it is applied to several systems that are difficult to get satisfactory response by conventional PD controllers or PI controllers.

  • PDF

Design and Implementation of a Fifthly Expanded Triangular Fractal Antenna (5차 확장 삼각형 프랙털 안테나 설계 및 구현)

  • 최재연
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.6 no.4
    • /
    • pp.616-623
    • /
    • 2002
  • The fractal expanded antenna with the configuration of a triangular microstrip patch antenna is presented and analyzed. In the fundamental and higher mode of TFA(Triangular Fractal Antenna), resonant frequencies are controlled by changing the scaling factor. It is observed that increasing scaling factor makes the resonant frequency be spread, and decreasing scaling factor makes it be concentrated. The scaling factor is varied as the expansion and concentration of resonant frequencies. The resonant frequency in each fractal patch element is observed log -periodically. The TFA can be applied to the multiband system.

Depth Scaling Strategy Using a Flexible Damping Factor forFrequency-Domain Elastic Full Waveform Inversion

  • Oh, Ju-Won;Kim, Shin-Woong;Min, Dong-Joo;Moon, Seok-Joon;Hwang, Jong-Ha
    • Journal of the Korean earth science society
    • /
    • v.37 no.5
    • /
    • pp.277-285
    • /
    • 2016
  • We introduce a depth scaling strategy to improve the accuracy of frequency-domain elastic full waveform inversion (FWI) using the new pseudo-Hessian matrix for seismic data without low-frequency components. The depth scaling strategy is based on the fact that the damping factor in the Levenberg-Marquardt method controls the energy concentration in the gradient. In other words, a large damping factor makes the Levenberg-Marquardt method similar to the steepest-descent method, by which shallow structures are mainly recovered. With a small damping factor, the Levenberg-Marquardt method becomes similar to the Gauss-Newton methods by which we can resolve deep structures as well as shallow structures. In our depth scaling strategy, a large damping factor is used in the early stage and then decreases automatically with the trend of error as the iteration goes on. With the depth scaling strategy, we can gradually move the parameter-searching region from shallow to deep parts. This flexible damping factor plays a role in retarding the model parameter update for shallow parts and mainly inverting deeper parts in the later stage of inversion. By doing so, we can improve deep parts in inversion results. The depth scaling strategy is applied to synthetic data without lowfrequency components for a modified version of the SEG/EAGE overthrust model. Numerical examples show that the flexible damping factor yields better results than the constant damping factor when reliable low-frequency components are missing.

Acoustic Echo Cancellation using the DUET Algorithm and Scaling Factor Estimation (잡음 상황에서 DUET 블라인드 신호 분리 알고리즘과 스케일 계수 추정을 이용한 음향 반향신호 제거)

  • Kim, K.J.;Seo, J.B.;Nam, S.W.
    • Proceedings of the KIEE Conference
    • /
    • 2006.10c
    • /
    • pp.416-418
    • /
    • 2006
  • In this paper, a new acoustic echo cancellation approach based on the DUET algorithm and scaling factor estimation is proposed to solve the scaling ambiguity in case of blind separation based acoustic echo cancellation in a noisy environment. In hands-free full-duplex communication system. acoustic noises picked up by the microphone are mixed with echo signal. For this reason, the echo cancellation system may provide poor performance. For that purpose, a degenerate unmixing estimation technique, adjusted in the time-frequency domain, is employed to separate undesired echo signals and noises. Also, since scaling and permutation ambiguities have not been solved in the blind source separation algorithm, kurtosis for the desired signal selection and a scaling factor estimation algorithm are utilized in this rarer for the separation of an echo signal. Simulation results demonstrate that the proposed approach yields better echo cancellation and noise reduction performances, compared with conventional methods.

  • PDF

Analysis of Subthreshold Characteristics for Double Gate MOSFET using Impact Factor based on Scaling Theory (스켈링이론에 가중치를 적용한 DGMOSFET의 문턱전압이하 특성 분석)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.9
    • /
    • pp.2015-2020
    • /
    • 2012
  • The subthreshold characteristics has been analyzed to investigate the effect of two gate in Double Gate MOSFET using impact factor based on scaling theory. The charge distribution of Gaussian function validated in previous researches has been used to obtain potential distribution in Poisson equation. The potential distribution was used to investigate the short channel effects such as threshold voltage roll-off, subthreshold swings and drain induced barrier lowering by varying impact factor for scaling factor. The impact factor of 0.1~1.0 for channel length and 1.0~2.0 for channel thickness are used to fit structural feature of DGMOSFET. The simulation result showed that the subthreshold swings are mostly effected by impact factor but are nearly constant for scaling factors. And threshold voltage roll-off and drain induced barrier lowering are also effected by both impact factor and scaling factor.

Adaptive Scaling Based on Vision in Micromanipulation

  • Lee, Jaehoon;Park, Jong-Oh;Yoon, Pil-Sang;Lee, Seok-Joo;Park, Jong-Hyeon;Kim, Kyunghwan
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2002.10a
    • /
    • pp.116.6-116
    • /
    • 2002
  • $\textbullet$ Concept of Adaptive Scaling Factor $\textbullet$ Initial Value and Boundary Conditions $\textbullet$ Adaptive Scaling Factor $\textbullet$ Simulation and Experimental Results

  • PDF

Scaling Factor Design Based Variable Step Size Incremental Resistance Maximum Power Point Tracking for PV Systems

  • Ahmed, Emad M.;Shoyama, Masahito
    • Journal of Power Electronics
    • /
    • v.12 no.1
    • /
    • pp.164-171
    • /
    • 2012
  • Variable step size maximum power point trackers (MPPTs) are widely used in photovoltaic (PV) systems to extract the peak array power which depends on solar irradiation and array temperature. One essential factor which judges system dynamics and steady state performances is the scaling factor (N), which is used to update the controlling equation in the tracking algorithm to determine a new duty cycle. This paper proposes a novel stability study of variable step size incremental resistance maximum power point tracking (INR MPPT). The main contribution of this analysis appears when developing the overall small signal model of the PV system. Therefore, by using linear control theory, the boundary value of the scaling factor can be determined. The theoretical analysis and the design principle of the proposed stability analysis have been validated using MATLAB simulations, and experimentally using a fixed point digital signal processor (TMS320F2808).