• Title/Summary/Keyword: Weighting method

Search Result 1,299, Processing Time 0.027 seconds

Reduced Computation Using the DFT Property in the Phase Weighting Method (위상 조절 방법에서 DFT 특성을 이용한 계산량 저감)

  • Ryu Heung-Gyoon;Hieu Nguyen Thanh
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.16 no.10 s.101
    • /
    • pp.1028-1035
    • /
    • 2005
  • OFDM system has high PAPR(Peak-to-Average-Power Ratio) problem. In this paper, we present a low complexity phase weighting method to reduce the computational quantity so that we can cut down the processing time of SPW method. Proposed method is derived from the DFT property of periodical sequences by which PAPR can be reduced efficiently. The simulation results show the same PAPR reduction efficiency of proposed method in comparison with conventional methods. It can reduce 2.15 dB of PAPR with two phase factors and 3.95 dB of PAPR with four phase factors. The computation analysis shows significant improvement in the low complexity phase weighting method.

Digital Watermarking Based on Adaptive Threshold and Weighting Factor Decision Method (적응적 임계치와 가중치 결정 방법에 기반한 디지털 워터마킹)

  • Lim, Ho;Kim, Jin-Young
    • Proceedings of the IEEK Conference
    • /
    • 2000.06d
    • /
    • pp.123-126
    • /
    • 2000
  • In this paper, we propose new watermarking technique using weighting factor decision method in the watermark embedding step and adaptive threshold decision method in the watermark extracting step. In our method, we are determined weighting factor in simple by calculating distance between pixel coefficient and neighborhood pixel coefficients and threshold is adaptively determined by searching the minimized extract error value using histogram of difference value.

  • PDF

Design and Performance Analysis of the SPW Method for PAPR Reduction in OFDM System (OFDM 시스템에서 PAPR 처감을 위한 SPW 방식의 설계와 성능 분석)

  • 이재은;유흥균;정영호;함영권
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.14 no.7
    • /
    • pp.677-684
    • /
    • 2003
  • This paper addresses the subblock phase weighting(SPW) method to reduce the PAPR in OFDM system. This method divides the input block of OFDM signal into many subblocks and lower the peak power by weighting the phase of each subblocks properly. SPW method can be realized by only one IFFT. PAPR reduction performance is novelly examined when the adjacent, interleaved and random subblock partitioning schemes are used in the SPW system. The random subblock partition scheme has the most effective. More subblocks can effectively reduce the PAPR, but there is a problem that the processing time of iteration is increased. We propose a new weighting factor combination of the complementary sequence characteristic with threshold technique. OFDM data can be recovered by the inserted side information of weighting factor in the feed forward type. Also, BER performance of this SPW system is analyzed when error happens in the side information.

Data De-weighting in Matrix Pencil Method (매트릭스 팬슬 방법의 데이터 불균형 제거 기법)

  • Koh, Jin-Hwan;Xu, Xiaowen;Ryu, Beong-Ju;Lee, Jae-Hun;Lee, Jung-Sup
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.36 no.8A
    • /
    • pp.741-747
    • /
    • 2011
  • Matrix Pencil method is one of the promising method to estimate DOA in non-stationary, multi-path coherent environment. Not only the Matrix Pencil Method offers better resolution than the conventional approach using covariance matrix, but also it is computationally very efficient. In this paper, we presented an effect of unbalanced data weighting in the formulation of the Matrix Pencil method. A new formulation has been suggested to mitigate the effect of unbalanced data weighting. Numerical simulation demonstrated that the proposed method can successfully eliminate the problem of unbalanced data weighting.

Gradient Descent Approach for Value-Based Weighting (점진적 하강 방법을 이용한 속성값 기반의 가중치 계산방법)

  • Lee, Chang-Hwan;Bae, Joo-Hyun
    • The KIPS Transactions:PartB
    • /
    • v.17B no.5
    • /
    • pp.381-388
    • /
    • 2010
  • Naive Bayesian learning has been widely used in many data mining applications, and it performs surprisingly well on many applications. However, due to the assumption that all attributes are equally important in naive Bayesian learning, the posterior probabilities estimated by naive Bayesian are sometimes poor. In this paper, we propose more fine-grained weighting methods, called value weighting, in the context of naive Bayesian learning. While the current weighting methods assign a weight to each attribute, we assign a weight to each attribute value. We investigate how the proposed value weighting effects the performance of naive Bayesian learning. We develop new methods, using gradient descent method, for both value weighting and feature weighting in the context of naive Bayesian. The performance of the proposed methods has been compared with the attribute weighting method and general Naive bayesian, and the value weighting method showed better in most cases.

Application of GA to Design on Optimal Multivariable $H_{\infty}$ Control System (최적 다변수 $H_{\infty}$ 제어 시스템의 설계를 위한 GA의 적용)

  • 황현준;김동완;정호성;박준호;황창선
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.5 no.3
    • /
    • pp.257-266
    • /
    • 1999
  • The aim of this paper is to suggest a design method of the optimal multivariable $H_{\infty}$ control system using genetic algorithm (GA). This $H_{\infty}$ control system is designed by applying GA to the optimal determination of weighting functions and design parameter $\gamma$ that are given by Glover-Doyle algorithm which can design $H_{\infty}$ controller in the state space. The first method to do this is that the gains of weighting functions and $\gamma$ are optimized simultaneously by GA with tournament method. And the second method is that not only the gains and $\gamma$ but also the dynamics of weighting functions are optimized at the same time by eA with roulette-wheel method. The effectiveness of this $H_{\infty}$ control system is verified by computer simulation.

  • PDF

New Weighting Factor of 2D Isotropic-Dispersion Finite Difference Time Domain(ID-FDTD) Algorithm

  • Zhao, Meng;Koh, Il-Suek
    • Journal of electromagnetic engineering and science
    • /
    • v.8 no.4
    • /
    • pp.139-143
    • /
    • 2008
  • In this paper, a new scheme to calculate the weighting factor of the 2-D isotropic-dispersion finite difference time domain(ID-FDTD) is proposed. The weighting factor in [1] was formulated in free space, so that it may not be optimal in dielectric media. Therefore, the weighting factor was reformulated by considering the material properties and using the least mean square method. As a result, a minimum numerical dispersion error for any dielectric media is guaranteed.

Integration of Current-mode VSFD with Multi-valued Weighting Function

  • Go, H.M.;Takayama, J.;Ohyama, S.;Kobayashi, A.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.921-926
    • /
    • 2003
  • This paper describes a new type of the spatial filter detector (SFD) with variable and multi-valued weighting function. This SFD called variable spatial filter detector with multi-valued weighting function (VSFDwMWF) uses current-mode circuits for noise resistance and high-resolution weighting values. Total weighting values consist of 7bit, 6-signal bit and 1-sign bit. We fabricate VSFDwMWF chip using Rohm 0.35${\mu}$m CMOS process. VSFDwMWF chip includes two-dimensional 10${\times}$13 photodiode array and current-mode weighting control circuit. Simulation shows the weighting values are varied and multi-valued by external switching operation. The layout of VSFDwMWF chip is shown.

  • PDF

A Proposal of an Interpolation Method of Missing Wind Velocity Data in Writing a Typical Weather Data (표준기상데이터 작성 시 누락된 풍속 데이터의 보간 방법 제안)

  • Park, So-Woo;Kim, Joo-wook;Song, Doo-sam
    • Journal of the Korean Solar Energy Society
    • /
    • v.37 no.6
    • /
    • pp.79-91
    • /
    • 2017
  • The meteorological data of 1 hour interval are required to write a typical weather data for building energy simulation. However, many meterological data are missing and the interpolation method to recover the missing data is required. Especially, lots of meterological data are replicated by linear interpolation method because the changes are not significant. While, the wind velocity fluctuates with the time or locations, so linear interpolation method is not appropriate in interpolation of the wind velocity data. In this study, three interpolation methods, using surrounding wind velocity data, Inverse Distance Weighting (IDW), Revised Inverse Distance Weighting (IDW-r), were analyzed considering the characteristics of wind velocity. The Revised Inverse Distance Weighting method, proposed in this study, showed the highest reliability in restoration of the wind velocity data among the analyzed methods.

A method for deciding weighting matrices by considering a steady-state deviation in a LQ tracking problem (정상상태 추적편차를 고려한 가중행렬의 선택)

  • 이진익;전기준
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1989.10a
    • /
    • pp.473-476
    • /
    • 1989
  • Quadratic weighting matrices have an effect on the transition and steady state responses in a LQ tracking problem. They are usually decided on trial and error in order to get a good response. In this paper a method is presented which calculates a steady - state deviation without solving Riccati equation. By using this method, a new procedure for selecting the weighting matrices is proposed when a tolerance on the steady - state deviation is given.

  • PDF