scholarly journals A Parametric Time-Frequency Conditional Granger Causality Method Using Ultra-Regularized Orthogonal Least Squares and Multiwavelets for Dynamic Connectivity Analysis in EEGs

2019 ◽  
Vol 66 (12) ◽  
pp. 3509-3525 ◽  
Author(s):  
Yang Li ◽  
Mengying Lei ◽  
Weigang Cui ◽  
Yuzhu Guo ◽  
Hua-Liang Wei
Keyword(s):  
Least Squares ◽  
Granger Causality ◽  
Connectivity Analysis ◽  
Time Frequency ◽  
Orthogonal Least Squares ◽  
Dynamic Connectivity

Orthogonal Least Squares Detector for Generalized Spatial Modulation

2021 ◽  
pp. 1-1
Author(s):  
Jinming Wen ◽  
Jie Li ◽  
Huanmin Ge ◽  
Zhengchun Zhou ◽  
Weiqi Luo
Keyword(s):  
Least Squares ◽  
Spatial Modulation ◽  
Orthogonal Least Squares

PYRAMIDAL HYBRID APPROACH: WAVELET NETWORK WITH OLS ALGORITHM-BASED IMAGE CLASSIFICATION

2011 ◽  
Vol 09 (01) ◽  
pp. 111-130 ◽  
Author(s):  
OLFA JEMAI ◽  
MOURAD ZAIED ◽  
CHOKRI BEN AMAR ◽  
MOHAMED ADEL ALIMI
Keyword(s):  
Least Squares ◽  
Image Classification ◽  
Network Architecture ◽  
Hybrid Approach ◽  
Learning Ability ◽  
Wavelet Network ◽  
Wavelet Networks ◽  
Orthogonal Least Squares ◽  
Colour Image ◽  
Beta Wavelet

Taking advantage of both the scaling property of wavelets and the high learning ability of neural networks, wavelet networks have recently emerged as a powerful tool in many applications in the field of signal processing such as data compression, function approximation as well as image recognition and classification. A novel wavelet network-based method for image classification is presented in this paper. The method combines the Orthogonal Least Squares algorithm (OLS) with the Pyramidal Beta Wavelet Network architecture (PBWN). First, the structure of the Pyramidal Beta Wavelet Network is proposed and the OLS method is used to design it by presetting the widths of the hidden units in PBWN. Then, to enhance the performance of the obtained PBWN, a novel learning algorithm based on orthogonal least squares and frames theory is proposed, in which we use OLS to select the hidden nodes. In the simulation part, the proposed method is employed to classify colour images. Comparisons with some typical wavelet networks are presented and discussed. Simulations also show that the PBWN-orthogonal least squares (PBWN-OLS) algorithm, which combines PBWN with the OLS algorithm, results in better performance for colour image classification.

Identification of Time-Varying Time Constants of Thermocouple Sensors and Its Application to Temperature Measurement

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Kenneth Kar ◽  
Akshya K. Swain ◽  
Robert Raine
Keyword(s):  
Kalman Filter ◽  
Least Squares ◽  
Time Constant ◽  
Identification Problem ◽  
Basis Functions ◽  
New Technique ◽  
Ratio Test ◽  
Time Varying ◽  
Time Constants ◽  
Orthogonal Least Squares

The present study addresses the problem of estimating time-varying time constants associated with thermocouple sensors by a set of basis functions. By expanding each time-varying time constant onto a finite set of basis sequences, the time-varying identification problem reduces to a parameter estimation problem of a time-invariant system. The proposed algorithm, to be called as orthogonal least-squares with basis function expansion algorithm, combines the orthogonal least-squares algorithm with an error reduction ratio test to include significant basis functions into the model, which results in a parsimonious model structure. The performance of the method was compared with a linear Kalman filter. Simulations on engine data have demonstrated that the proposed method performs satisfactorily and is better than the Kalman filter. The new technique has been applied in a Stirling cycle compressor. The sinusoidal variations in time constant are tracked properly using the new technique, but the linear Kalman filter fails to do so. Both model validation and thermodynamic laws confirm that the new technique gives unbiased estimates and that the assumed thermocouple model is adequate.

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