Skip to content


  • Review Article
  • Open Access

Fluctuation Analyses for Pattern Classification in Nondestructive Materials Inspection

EURASIP Journal on Advances in Signal Processing20102010:262869

  • Received: 30 December 2009
  • Accepted: 25 June 2010
  • Published:


We review recent work on the application of fluctuation analyses of time series for pattern classification in nondestructive materials inspection. These analyses are based on the evaluation of time-series fluctuations across time intervals of increasing size, and were originally introduced in the study of fractals. A number of examples indicate that this approach yields relevant features allowing the successful classification of patterns such as (i) microstructure signatures in cast irons, as probed by backscattered ultrasonic signals; (ii) welding defects in metals, as probed by TOFD ultrasonic signals; (iii) gear faults, based on vibration signals; (iv) weld-transfer modes, as probed by voltage and current time series; (v) microstructural composition in stainless steel, as probed by magnetic Barkhausen noise and magnetic flux signals.


  • Time Series
  • Welding
  • Cast Iron
  • Magnetic Flux
  • Quantum Information

Publisher note

To access the full article, please see PDF.

Authors’ Affiliations

Instituto de Física Universidade de São Paulo, 05508-090 São Paulo, SP, Brazil
Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Ceará, 60455-760 Fortaleza, CE, Brazil