• Title/Summary/Keyword: compensation scheme

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A Study of Compensation Algorithm for Localization based on Equivalent Distance Rate using Estimated Location Coordinator Searching Scheme (예상 위치좌표 탐색기법을 적용한 균등거리비율 기반 위치인식 보정 알고리즘 연구)

  • Kwon, Seong-Ki;Lee, Dong-Myung;Lee, Chang-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3571-3577
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    • 2010
  • The estimated location coordinator exploration scheme and the E&E(Equivalent distance rate & Estimated location coordinator exploration) compensation algorithm for localization is proposed, and the performance of the E&E is analyzed in this paper. The proposed scheme is adapted to the AEDR(Algorithm for localization using the concept of Equivalent Distance Rate). From several experiments, it is confirmed that the performance of the localization compensation in SDS-TWR is improved from 0.60m to 0.34m in four experimental scenarios, and the performance of the localization compensation ratio of the E&E is also better than that of the AEDR as a level of maximum 15%. It can be thought that the proposed localization compensation algorithm E&E can be sufficiently applicable to various localization applications because the performance of the localization error rate of the E&E is measured as less than 1m in 99% of the total performance experiments.

Minimum Classification Error Training to Improve Discriminability of PCMM-Based Feature Compensation (PCMM 기반 특징 보상 기법에서 변별력 향상을 위한 Minimum Classification Error 훈련의 적용)

  • Kim Wooil;Ko Hanseok
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.1
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    • pp.58-68
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    • 2005
  • In this paper, we propose a scheme to improve discriminative property in the feature compensation method for robust speech recognition under noisy environments. The estimation of noisy speech model used in existing feature compensation methods do not guarantee the computation of posterior probabilities which discriminate reliably among the Gaussian components. Estimation of Posterior probabilities is a crucial step in determining the discriminative factor of the Gaussian models, which in turn determines the intelligibility of the restored speech signals. The proposed scheme employs minimum classification error (MCE) training for estimating the parameters of the noisy speech model. For applying the MCE training, we propose to identify and determine the 'competing components' that are expected to affect the discriminative ability. The proposed method is applied to feature compensation based on parallel combined mixture model (PCMM). The performance is examined over Aurora 2.0 database and over the speech recorded inside a car during real driving conditions. The experimental results show improved recognition performance in both simulated environments and real-life conditions. The result verifies the effectiveness of the proposed scheme for increasing the performance of robust speech recognition systems.

Adaptive Predistortion Compensation for Nonlinearity of High Power Amplifiers

  • Ding, Yuanming;Ohmori, Hiromitsu;Sano, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.122-127
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    • 2003
  • In this paper, an adaptive predistortion scheme is proposed to compensate nonlinear distortions caused by high power amplifiers (HPA) in OFDM systems. A complex Wiener-Hammerstein model (WHM) is used to describe input-output relationship of HPA with linear dynamics. The predistorter is directly identified by complex power series model with memory, which is an approximate inverse of the HPA expressed by the WHM. The effectiveness of the proposed adaptive compensation scheme is validated by numerical simulation for 64QAM-OFDM systems.

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A non-model based robot manipulator control using neural networks (무모형 로봇을 위한 신경 회로망 제어 방식)

  • Jung, Seul
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.698-701
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    • 1996
  • A novel neural network control scheme is proposed to identify the inverse dynamic model of robot manipulator and to compensate for uncertainties in robot dynamics. The proposed controller is called reference compensation technique(RCT) by compensating at reference input trajectory. The proposed RCT scheme has many benefits due to the differences in compensating position and learning algorithm. Since the compensation is done outside the plant it can be applied to many control systems without modifying the inside controller. It performs well with low controller gain because the operating range of input values is small and the output of the neural network controller is amplified through the controller gain. The back-propagation algorithm is used to train and simulations of three link robot manipulator are carried out to prove the proposed controller's performances.

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A Three-Phase Parallel Active Power Filter Operating with PCC Voltage Compensation by Controlling Reactive Power (무효전력 제어에 의한 PCC전압 보상을 갖는 삼상 병렬형 능동전력필터)

  • Lee, U-Cheol;Hyeon, Dong-Seok;Lee, Taek-Gi
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.3
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    • pp.211-218
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    • 2000
  • The performance and dynamic characteristics of three-phase active power filter with PCC voltage compensation is presented and analyzed in this paper. The characteristics of parallel active filter are discussed when they are applied to nonlinear loads with current source and voltage source type, the characteristics of voltage compensator and comparison of two functions are discussed. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. First, it operates as a conventional active filter with reactive power compensation while PCC voltage is in a certain range. Second, is operates as a voltage compensator while PCC voltage is out of range. Finally, the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rated at 10KVA.

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Harmonic Current Compensation based on Three-phase Three-level Shunt Active Filter using Fuzzy Logic Current Controller

  • Salim, Chennai;Benchouia, M.T.;Golea, A.
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.595-604
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    • 2011
  • A three-phase three-level shunt active filter controlled by fuzzy logic current controller which can compensate current harmonics generated by nonlinear loads is presented. Three-level inverters and fuzzy controllers have been successfully employed in several power electronic applications these past years. To improve the conventional pwm controller performance, a new control scheme based on fuzzy current controller is adopted for three-level (NPC) shunt active filter. The scheme is designed to improve compensation capability of APF by adjusting the current error using a fuzzy rule. The inverter current reference signals required to compensate harmonic currents use the synchronous reference detection method. This technique is easy to implement and achieves good results. To maintain the dc voltage across capacitor constant and reduce inverter losses, a proportional integral voltage controller is used. The simulation of global system control and power circuits is performed using Matlab-Simulink and SimPowerSystem toolbox. The results obtained in transient and steady states under various operating conditions show the effectiveness of the proposed shunt active filter based on fuzzy current controller compared to the conventional scheme.

Novel Doppler effects compensation schemes based on constellation estimation of OFDM system

  • Lee, Byung-Seub
    • Journal of Satellite, Information and Communications
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    • v.12 no.2
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    • pp.79-82
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    • 2017
  • A new and effective Doppler effects compensation scheme for orthogonal frequency division multiplex(OFDM) system based on constellation estimation is presented with analytical descriptions which quantitatively clarify the mechanism of inter-carrier interference(ICI). The proposed compensation techniques, applicable both frequency and time domain with remarkable accuracy, are crucial to the future OFDM system operating on ultra high speed mobile vehicles.

The Differential Benefits of Reputed Generalists CEOs over Tenure

  • Koo, Kwang-Joo
    • Asia-Pacific Journal of Business
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    • v.12 no.4
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    • pp.87-105
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    • 2021
  • Purpose - The purpose of this study was to explores how CEO general human capital, one of the most critical issues in recent research, affects compensation schemes. Design/methodology/approach - This study collected the CEOs of S&P500 companies from 2001 to 2009 and contains 4,155 CEO-firm-year observations and 704 different CEOs. Findings - First, only contingent bonus is affected by general human capital and reputation. Second, the career concerns of CEOs are relevant, especially when explaining CEO tenure. Third, we offer an alternative view of what determines the level of cash compensation schemes and the factors that affect the running of a firm. Fourth, we also suggest that the increase in general human capital can be explained by the increase in its relative importance in managing a modern firm. Overall, the results of this study do not only contribute to academics but also important to boards and shareholders. Research implications or Originality - This study intends to fill the gap in the extant literature by examining the relationship between general human capital and compensation schemes.First, we add to the compensation literature by arguing that a cash compensation scheme is efficient for generalist CEOs. We break down CEO cash compensation schemes into fixed and contingent bonus compensation and investigate whether general human capital differentially affects CEO cash compensation schemes, and thus, the sensitivity to unequal pay for human capital. Second, we contribute to the reputation literature by arguing that CEO perceived reputation also affects CEO compensation schemes.

A Technique Combining the Path Calibration and Nonlinear Compensation in a Transmitting Antenna Array System (송신 배열 안테나의 경로 보정과 비선형 보상의 결합 기술)

  • Lim, Sun-Min;Kim, Min;Eun, Chang-Soo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.5
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    • pp.27-36
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    • 2012
  • We propose a new scheme combining the calibration of the path imperfections and the compensation of HPA nonlinearity in the downlink OFDM smart antenna systems. We use a two term third-order polynomial (without second-order term) and the indirect learning architecture for calibration and compensation, to make each path of the antenna array have equal characteristics. We test our scheme with computer simulations. The result shows that, with the addition of only one third-order term, the adverse nonlinear effects as well as the those of linear imperfections can be effectively compensated.

Adaptive Compensation Method Using the Prediction Algorithm for the Doppler Frequency Shift in the LEO Mobile Satellite Communication System

  • You, Moon-Hee;Lee, Seong-Pal;Han, Young-Yearl
    • ETRI Journal
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    • v.22 no.4
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    • pp.32-39
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    • 2000
  • In low earth orbit (LEO) satellite communication systems, more severe phase distortion due to Doppler shift is frequently detected in the received signal than in cases of geostationary earth orbit (GEO) satellite systems or terrestrial mobile systems. Therefore, an estimation of Doppler shift would be one of the most important factors to enhance performance of LEO satellite communication system. In this paper, a new adaptive Doppler compensation scheme using location information of a user terminal and satellite, as well as a weighting factor for the reduction of prediction error is proposed. The prediction performance of the proposed scheme is simulated in terms of the prediction accuracy and the cumulative density function of the prediction error, with considering the offset variation range of the initial input parameters in LEO satellite system. The simulation results showed that the proposed adaptive compensation algorithm has the better performance accuracy than Ali's method. From the simulation results, it is concluded the adaptive compensation algorithm is the most applicable method that can be applied to LEO satellite systems of a range of altitude between 1,000 km and 2,000 km for the general error tolerance level, M = 250 Hz.

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