About Book

The world of engineering is filled with signals like images from remote space probes, voltages generated by the heart and brain, radar and sonar echoes, seismic vibrations, and countless other applications. The fourier transform decomposes a function of time into the frequencies that make it up, similarly to how a musical chord can be expressed as the amplitude of its constituent notes. The fourier transform of a function of time itself is a complex-valued function of frequency, whose absolute value represents the amount of that frequency present in the original function, and whose complex argument is the phase offset of the basic sinusoid in that frequency. Signal processing is the art and science of modifying acquired time-series data for the purpose of analysis or enhancement. Signal processing is an area which either implicitly or explicitly forms the fundamental bedrock of a very wide range of applications or needs in our modern society. This book is aimed at providing recent advances in fourier transform and signal processing. It covers maintenance management, optical signal processing, seismic signal processing, electromagnetic signal processing, signal processing techniques, optimization techniques, structural integrity and digital algebraic method. It is devoted to the latest advancements in signal and information processing. The aim of this book is to keep a record of the advanced research and promote the research work in the areas. This comprehensive book is anticipated for a rapid dissemination of knowledge and experience to engineers and scientists working in the research, development or practical application of signal processing. This book is a very valuable addition to the signal processing literature.

Preface ..................................................................................................................... v

1. Digital Algebraic Method for Processing Complex Signals for Radio

Monitoring Systems ............................................................................................. 1

Abstract ........................................................................................................... 1

1. Introduction ................................................................................................... 1

2. Mathematical model of OFDM signals ....................................................... 2

3. The main stages of the structural analysis of OFDM signals ................. 4

4. Group algebraic demodulation ................................................................. 13

5. Conclusions .................................................................................................. 20

2. Application and Challenges of Signal Processing Techniques for Lamb

Waves Structural Integrity Evaluation: Part B-Defects Imaging and

Recognition Techniques .................................................................................... 23

Abstract ......................................................................................................... 23

1. Introduction ................................................................................................. 24

2. Defect imaging techniques .......................................................................... 24

3. Intelligent recognition techniques ............................................................. 40

4. Summary and conclusions ......................................................................... 46

Acknowledgements ..................................................................................... 48

Conflict of interest ....................................................................................... 48

3. Application and Challenges of Signal Processing Techniques for Lamb

Waves Structural Integrity Evaluation: Part A-Lamb Waves Signals Emitting

and Optimization Techniques .......................................................................... 58

Abstract ......................................................................................................... 58

1. Introduction ................................................................................................. 59

2. Transducers and specific Lamb wave mode emitting ........................... 62

3. Signal optimization techniques ................................................................. 68

4. Summary and conclusions ......................................................................... 78

Acknowledgements ..................................................................................... 80

Conflict of interest ....................................................................................... 80

4. Graphene-Enhanced Optical Signal Processing ........................................... 91

Abstract ......................................................................................................... 91

1. Introduction ................................................................................................. 92

2. Optical properties of graphene .................................................................. 94

3. Fabrication and characterization of graphen-assisted nonlinear

optical devices .............................................................................................. 95

4. Graphene enhanced nonlinear optical device for optical transport

networks signal processing ....................................................................... 98

5. GSMR-enhanced nonlinear optical device for on-chip optical

signal processing ....................................................................................... 105

6. Discussions and conclusions ................................................................... 112

Acknowledgements ................................................................................... 115

5. Real-Time Electromagnetic Signal Processing: Principles and

Illustrations ........................................................................................................ 120

Abstract ....................................................................................................... 120

1. Introduction ............................................................................................... 121

2. Radio analog signal processing (R-ASP) ................................................ 123

3. Electromagnetic phasers ........................................................................... 124

4. Applications ............................................................................................... 135

5. Conclusions ................................................................................................ 141

6. Application of Local Wave Decomposition in Seismic Signal

Processing .......................................................................................................... 147

Abstract ....................................................................................................... 147

1. Introduction ............................................................................................... 148

2. The general theory of local wave decom-position ............................... 149

3. Applications ............................................................................................... 154

4. Conclusion .................................................................................................. 170

Acknowledgements ................................................................................... 170

7. Optical Signal Processing: Data Exchange .................................................. 174

1. Introduction ............................................................................................... 174

2. Concept of data exchange ......................................................................... 176

3. Recent advances for robust data exchange ........................................... 177

4. Discussions ................................................................................................. 198

5. Conclusion .................................................................................................. 199

Acknowledgements ................................................................................... 200

8. Maintenance Management Based on Signal Processing .......................... 207

1. Wind Turbines ........................................................................................... 207

2. Wavelet transform .................................................................................... 211

3. Condition Monitoring for engine-generator mechanism .................... 217

4. Conclusions ................................................................................................ 232

Citation ................................................................................................................ 243

Index .................................................................................................................... 245

About Author

Edwin Piestun obtained his Ph.D. in Physics and Applied Mathematics from Public University, Porto. He has diverse areas of academic interests including speech signal processing, digital image processing and statistical signal processing. He serves as a guest lecturer at several renowned universities across Europe. He has been an invited speaker at numerous international conferences across the globe. He has written several articles, research report, and papers on signal and information processing, software and systems, distributed processing and innovative techniques in computing.