The adaptive input estimation approach which is based on the Kalman filter technique combined with a variable forgetting factor as a weighting function in recursive least-squares algorithm is adopted to investigate th...
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The adaptive input estimation approach which is based on the Kalman filter technique combined with a variable forgetting factor as a weighting function in recursive least-squares algorithm is adopted to investigate the estimation of impulsive heat flux of inverse heat conduction problem from experimental data. Four specific charge designs for igniters with impulsive heat flux input are solved to illustrate the effectiveness and good accuracy of the presented method. (C) 2000 The Franklin Institute. Published by Elsevier Science Ltd. All rights reserved.
In this paper, a clustering-based method is proposed for automatically constructing a multi-input Takagi-Sugeno (TS) fuzzy model where only the input-output data of the identified system are available. The TS fuzzy mo...
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In this paper, a clustering-based method is proposed for automatically constructing a multi-input Takagi-Sugeno (TS) fuzzy model where only the input-output data of the identified system are available. The TS fuzzy model is automatically generated LS the process of structure identification and parameter identification. In the structure identification step, a clustering method is proposed to provide a systematic procedure to partition the input space so that the number of Fuzzy rules and the shapes of fuzzy sets in the premise part are determined from the given input-output data. In the parameter identification step, the recursive least-squares algorithm is applied to choose the parameter values in the consequent part from the given input-output data. Finally, two examples are used to illustrate the effectiveness of the proposed method.
The recursiveleast-squares (RLS) algorithm has been used in the adaptive synthesis filter bank for fast convergence. However, because of interpolation operations involved in the synthesis process, fast RLS algorithms...
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The recursiveleast-squares (RLS) algorithm has been used in the adaptive synthesis filter bank for fast convergence. However, because of interpolation operations involved in the synthesis process, fast RLS algorithms cannot be applied. In this Letter, an approach is proposed that can formulate subband reconstruction as a multichannel filtering problem. This formulation allows the application of fast multichannel RLS algorithms and substantial reduction in computational complexity.
This study demonstrates that adaptive filters can be used successfully to remove noise from duplicate paleoceanographic time-series. Conventional methods for noise canceling such as fixed filters cannot be applied to ...
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This study demonstrates that adaptive filters can be used successfully to remove noise from duplicate paleoceanographic time-series. Conventional methods for noise canceling such as fixed filters cannot be applied to paleoceanographic time-series if optimal filtering is to be achieved, because the signal-to-noise ratio is unknown and varies with time. In contrast, an adaptive filter automatically extracts information without any prior initialization of the filter parameters. Two basic adaptive filtering methods, the gradient-based stochastic least-mean-squares (LMS) algorithm and the recursiveleast-squares (RLS) algorithm have been modified for paleoceanographic applications. The RLS algorithm can he used for noise removal from duplicate records corrupted by stationary noise, for example, carbonate measurements, species counts, or density data. The RLS filter performance is characterized by high accuracy and fast rate of convergence. The modified LMS algorithm out-performs the RLS procedure in a nonstationary environment (e.g., stable isotope records) but at the price of a slower rate of convergence and a reduced accuracy in the final estimate. The application of both algorithms is demonstrated by means of carbonate and stable isotope data.
A third-order cumulants-based adaptive recursiveleast-squares (CRLS) algorithm for the identification of time-invariant nonminimum phase systems, as well as time-variant nonminimum phase systems, has been successfull...
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A third-order cumulants-based adaptive recursiveleast-squares (CRLS) algorithm for the identification of time-invariant nonminimum phase systems, as well as time-variant nonminimum phase systems, has been successfully developed, As higher order cumulants preserve both the magnitude and the phase information of received signals, they have been considered as powerful signal processing tools for nonminimum phase systems, In this paper, the development of the CRLS algorithm is described and examined, A cost function based on the third-order cumulant and the third-order cross cumulant is defined for the development of the CRLS system identification algorithm, The CRLS algorithm is then applied to different moving average (MA) and autoregressive moving average (ARMA) models, In the case of identifying the parameters of an MA model, a direct application of the CRLS algorithm is adequate, When dealing with an ARMA model, the poles and the zeros are estimated separately, In estimating the zeros of the ARMA model, the construction of a residual time-series sequence for the MA part is required, Simulation results indicate that the CRLS algorithm is capable of identifying nonminimum phase and time-varying systems, In addition, because of the third-order cumulant properties, the CRLS algorithm can suppress Gaussian noise and is capable of providing an unbiased estimate in a noisy environment.
Power systems are non-linear and they are often subjected to random disturbances. Therefore stochastic controllers with on-line system identification are ideally suited to power system control problems. Experience wit...
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Power systems are non-linear and they are often subjected to random disturbances. Therefore stochastic controllers with on-line system identification are ideally suited to power system control problems. Experience with a real time implementation of an adaptive power system stabiliser to damp the dynamic oscillations of a power system is presented. A multi-input multi-output (MIMO) pole shifting control algorithm together with a least-square system identification is used. The system identification is improved using a variable forgetting factor in the recursive least-squares algorithm. The computation time was greatly reduced by streamlining the identification algorithm using the sparse nature of the matrices associated with the computation and by using parallel processing techniques. The controller was tested in real time using a physical model of a power system. The results show that the damping of the power system dynamic oscillations can be improved by using this controller.
A new adaptive diversity-equalisation suitable for mobile radio signal transmission in the mobile radio fast fading environment is proposed. Adaptivity of the diversity-equalisation is enhanced by employing the recurs...
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A new adaptive diversity-equalisation suitable for mobile radio signal transmission in the mobile radio fast fading environment is proposed. Adaptivity of the diversity-equalisation is enhanced by employing the recursive least-squares algorithm (RLS) with exponential weighting and two newly proposed techniques: bi-directional equalisation (BDE) and transmitter time-diversity (TDD). Computer simulation shows that QPSK transmission performance equivalent to that of four-branch diversity can be obtained with small impairment.
The paper describes the design and application of an adaptive controller which overcomes the nonlinearity of the turbogenerator system. The controller tracks the operating conditions and updates an optimal controller ...
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The paper describes the design and application of an adaptive controller which overcomes the nonlinearity of the turbogenerator system. The controller tracks the operating conditions and updates an optimal controller as conditions change. Modelling of the turbogenerator employs an output prediction equation and recursive least-squares algorithm. The design uses identified input/output models, obtained over a range of operating conditions in thePQ-plane. Optimal controllers are designed offline for each zone of thePQ-plane and stored in online memory as a look-up table. The computer monitors the operating conditions of the generator and selects the corresponding optimal controller. The paper presents a practical comparison between the fixed-gain and the look-up-table controllers over a wide range of operating conditions, with various fault conditions, including transient stability boundaries of each controller. The results show that a very high quality of control may be achieved using this adaptive controller.
A modified form of the recursive least-squares algorithm is proposed. It is shown that this algorithm possesses interesting properties that are valid without any restriction on experimental conditions, or stability as...
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A modified form of the recursive least-squares algorithm is proposed. It is shown that this algorithm possesses interesting properties that are valid without any restriction on experimental conditions, or stability assumptions. It is thus especially well suited for adaptive control schemes.
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