Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Wavelet-Based Algorithm for Signal Analysis | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 38916 10 pages doi 2007 38916 Research Article Wavelet-Based Algorithm for Signal Analysis Norman C. F. Tse1 and L. L. Lai2 1 Division of Building Science and Technology City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong 2 School of Engineering and Mathematical Sciences City University Northampton Square London EC1V0HB UK Received 6 August 2006 Revised 12 October 2006 Accepted 24 November 2006 Recommended by Irene Y. H. Gu This paper presents a computational algorithm for identifying power frequency variations and integer harmonics by using waveletbased transform. The continuous wavelet transform CWT using the complex Morlet wavelet CMW is adopted to detect the harmonics presented in a power signal. A frequency detection algorithm is developed from the wavelet scalogram and ridges. A necessary condition is established to discriminate adjacent frequencies. The instantaneous frequency identification approach is applied to determine the frequencies components. An algorithm based on the discrete stationary wavelet transform DSWT is adopted to denoise the wavelet ridges. Experimental work has been used to demonstrate the superiority of this approach as compared to the more conventional one such as the fast Fourier transform. Copyright 2007 N. C. F. Tse and L. L. Lai. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Power quality has become a major concern for utility facility and consulting engineers in recent years. International as well as local standards have been formulated to address the power quality issues 1 . To the facility managers and end users frequent complaints by tenants customers on occasional power failures of computer and communication equipment and the .
