• Title/Summary/Keyword: adaptive performance

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Performance Analysis of AGC Applebaum Array for Multiple Narrowband Interference (다중의 협대역 간섭 신호에 대한 AGC Applebaum어레이의 성능 분석)

  • 윤동현;이규만;한동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6B
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    • pp.1092-1099
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    • 2000
  • An adaptive array system can effectively remove all received interferences by using adaptive algorithms even though the received signal condition is not known. The conventional adaptive array systems, however, cannot remove all interferences adaptively and converge very slowly when the eigenvalue spread of the input covariance matrix is large. In the paper, a new adaptive array system called an automatic gain controller (AGC) Applebaum array and its control algorithm are proposed to overcome the performance degradation of conventional Applebaum array in multiple interference conditions. The performance analysis of the proposed AGC Applebaum array is described under the condition of multiple narrowband interferences. Simulation results show the array output signal-to-noise ratio (SNR) of the AGC Applebaum array increases by 30dB compared to that of the conventional Applebaum array in the simulation condition. The gain of the AGC Applebaum array in the incident direction of a weaker interference is also shown to be lower than that of the conventional Applebaum array.

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Adaptive Input-Output Linearization Technique of Interior Permanent Magnet Synchronous Motor with Specified Output Dynamic Performance

  • Kim, Kyeong-Hwa;Baik, In-Cheol;Moon, Gun-Woo;Lee, Dae-Sik;Youn, Myung-Joong
    • Journal of Electrical Engineering and information Science
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    • v.1 no.2
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    • pp.58-66
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    • 1996
  • An adaptive input-output linearization technique of an interior permanent magnet synchronous motor with a specified output dynamic performance is proposed. The adaptive parameter estimation is achieved by a model reference adaptive technique where the stator resistance and the magnitude of flux linkage can be estimated with the current dynamic model and state observer. Using these estimated parameters, the linearizing control inputs are calculated. With these control inputs, the input-output linearization is performed and the load torque is estimated. The adaptation laws are derived by the Popov's hyperstability theory and the positivity concept. The robustness and the output dynamic performance of the proposed control scheme are verified through the computer simulations.

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Joint frame rate adaptation and object recognition model selection for stabilized unmanned aerial vehicle surveillance

  • Gyu Seon Kim;Haemin Lee;Soohyun Park;Joongheon Kim
    • ETRI Journal
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    • v.45 no.5
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    • pp.811-821
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    • 2023
  • We propose an adaptive unmanned aerial vehicle (UAV)-assisted object recognition algorithm for urban surveillance scenarios. For UAV-assisted surveillance, UAVs are equipped with learning-based object recognition models and can collect surveillance image data. However, owing to the limitations of UAVs regarding power and computational resources, adaptive control must be performed accordingly. Therefore, we introduce a self-adaptive control strategy to maximize the time-averaged recognition performance subject to stability through a formulation based on Lyapunov optimization. Results from performance evaluations on real-world data demonstrate that the proposed algorithm achieves the desired performance improvements.

Performance Improvement of MCMA Equalization Algorithm Using Adaptive Modulus (Adaptive Modulus를 이용한 MCMA 등화 알고리즘의 성능 개선)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.57-62
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    • 2014
  • This paper proposes the improving the equalization performance using the adaptive modulus concept to the MCMA blind equalizer in order to the reduction of intersymbol interference which occurs in the band limited and time dispersive communication channel. In MCMA blind algorithm, it is possible to reducing the amplitude and phase rotation of intersymbol interference without training sequence, the fixed constant modulus of transmission signal is used. But in proposed algorithm, the modulus are adaptively varies according to the equalizer output signal, then the improved equalization performance were obtained by the computer simulation. For this, the recovered signal constellation that is the output of the equalizer, the convergence performance by MSE, MD (maximum distortion) and residual isi characteristic learning curve were used. The propose algorithm has fairly good performance compared to the traditional MCMA algorithm in the same adaptive equalization algorithm.

Performance Improvement of CCA Blind Equalization Algorithm by Adaptive Step Size (적응 스텝 크기에 의한 CCA 블라인드 등화 알고리즘의 성능 개선)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.109-114
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    • 2016
  • This paper relates with the performance improvement of CCA (Compact Constellation Algorithm) equalization algorithm by adding the adaptive step size control in order to the minimization of intersymbol interference and additive noise effects that is occurs in the channel for digital radio transmissionl. In general, the fixed step size was used in order to adaptation in equalizer algorithm. But in proposed algorithm, the variable step size were adapted that is proposional to the nonlinear function of error signal for equalization. In order to show the improved equalizatation performance, the output signal constellation of equalizer, residual isi, maximum distortion, MSE and SER were used, then it were compared with the present CCA algorithm. As a result of computer simulation, the adaptive step size CCA has more better performance in the every performance index compared to the fixed step size CCA after in the steay state.

A Study of Learning and Performance Goal Orientation in Restaurant Servers' Up-Selling and Its Impact on Sales Behaviors and Sales Performance (레스토랑 직원의 Up-Selling에 대한 목적 지향성이 판매 행동과 판매 성과에 미치는 영향)

  • Kim, Young-Gab;Hong, Jong-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.5
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    • pp.776-784
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    • 2010
  • This study investigated causal relationships between goal orientation, sales and performance towards increasing the effectiveness of up-selling in internal promotion methods in family restaurants and provided implications about the hiring and training of sales people. The subjects were 232 sales people in family restaurants. The data were collected by self-administered questionnaires and analyzed by exploratory factor analysis, reliability analysis, comparative analysis of the average, and regression analysis. Results, showed that variations in goal orientation, sales, and performance depended on the age and experience of salespeople and that goal orientation makes adaptive selling more effective. It turned out that effort selling affects up-selling result than adaptive selling. Long-term workers were better than short-term workers in goal orientation, selling, and up-selling results, so human resource management needs to implement a long-term plan to enhance these effects. And, because effort selling is more effective than adaptive selling in up-selling results in family restaurants, effort selling requires training.

Performance Evaluation of Multi-Hazard Adaptive Smart Control Technique Based on Connective Control System (연결 제어 시스템 기반의 멀티해저드 적응형 스마트 제어 기술 성능 평가)

  • Kim, Hyun-Su
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.4
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    • pp.97-104
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    • 2018
  • A connected control method for the adjacent buildings has been studied to reduce dynamic responses. In these studies, seismic loads were generally used as an excitation. Recently, multi-hazards loads including earthquake and strong wind loads are employed to investigate control performance of various control systems. Accordingly, strong wind load as well as earthquake load was adopted to evaluate control performance of adaptive smart coupling control system against multi-hazard. To this end, an artificial seismic load in the region of strong seismicity and an artificial wind load in the region of strong winds were generated for control performance evaluation of the coupling control system. Artificial seismic and wind excitations were made by SIMQKE and Kaimal spectrum based on ASCE 7-10. As example buildings, two 20-story and 12-story adjacent buildings were used. An MR (magnetorheological) damper was used as an adaptive smart control device to connect adjacent two buildings. In oder to present nonlinear dynamic behavior of MR damper, Bouc-Wen model was employed in this study. After parametric studies on MR damper capacity, optimal command voltages for MR damper on each seismic and wind loads were investigated. Based on numerical analyses, it was shown that the adaptive smart coupling control system proposed in this study can provide very good control performance for Multi-hazards.

Performance Analysis of OFDM/QPSK-DMR System Using One-Tap Adaptive Equalizer over the Microwave Channel (Microwave 채널 환경에서 One-Tap 적응 등화기를 적용하는 OFDM/QPSK-DMR 시스템의 성능 분석)

  • Yang, Hee-Jin;Ahn, Jun-Bae;Oh, Chang-Heon;Cho, Sung-Joon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.398-402
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    • 2003
  • In this paper, we have analyzed the performance enhancement of OFDM/QPSK-DMR(Orthogonal Frequency Division Multiplexing/Quadrature Phase Shift Keying Modulation-Digital Microwave Radio)system using BL-PSF(Band Limited-Pulse Shaping Filter) over the microwave channel. For performance enhancement, we apply the one-tap adaptive equalizer for OFDM/QPSK-DMR system and compare with the BER performance of single carrier DMR system. Computer simulations confirm that the OFDM/QPSK-DMR system using one-tap adaptive equalizer has the same BER performance for the single carrier DMR system.

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MULTIVARIABLE WEIGHTED ADAPTIVE CONTROLLER DESIGN AND ITS APPLICATION

  • Lee, Kun-Yong
    • Proceedings of the KIEE Conference
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    • 1986.07a
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    • pp.132-135
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    • 1986
  • This paper shows that using the multivariable controller reduces the magnitude of fluctuations of the control signals which result improved control of the steam generator outputs. Comparison of the performance of the multivariable weighted adaptive controller(MWAC) with the performance of the existing PI controller and the self_tuning controller/1/, when the system goes through a transient mode, shows that the out-puts stay closer to their set points when they are controlled by the adaptive controller.

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Design of Neural Network Adaptive Control Law for Aircraft System Including Uncertainty

  • Kim, You-Dan;Shin, Dong-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.125.3-125
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    • 2001
  • Recently, aircraft is designed to have high maneuverable at high angle of attack. However, it is very hard to obtain the accurate dynamic model for the high performance, because aerodynamic characteristics are nonlinear and include a lot of uncertainties. Therefore, nonlinear controller without considering uncertainties may degrade the control system performance. On this paper, to overcome these defects, the neural networks based adaptive nonlinear controller is proposed making use of the backstepping technique. Neural networks are implemented to guarantee robustness to uncertainties caused by aerodynamic coefficients variation. The main feature of the proposed controller is that the adaptive controller is developed under the assumption ...

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