Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Asymmetrical singularities in real-world signals Kyoko Ohashi,1

Summary: Asymmetrical singularities in real-world signals
Kyoko Ohashi,1
Lui´s A. Nunes Amaral,2
Benjamin H. Natelson,3
and Yoshiharu Yamamoto1,3,4,*
Educational Physiology Laboratory, Graduate School of Education, University of Tokyo, Tokyo 113-0033, Japan
Department of Chemical Engineering, Northwestern University, Evanston, Illinois 60208, USA
Department of Neurosciences, New Jersey Medical School, East Orange, New Jersey 07018-1095, USA
PRESTO, Japan Science and Technology Corporation, Saitama 332-0012, Japan
Received 20 June 2003; published 24 December 2003
We generalize the wavelet transform modulus maxima approach in order to analyze positive and negative
changes separately and show different singularity spectra depending on the direction of changes in i human
heartbeat interval data during sympathetic blockade, ii time series of daytime human physical activity of
healthy individuals but not of patients with debilitating fatigue , and iii daily stock price records of the
Nikkei 225 in the period 1990­2002--but not of the S&P 500. We conclude that the analysis of asymmetrical
singularities provides deeper insights into the underlying complexity of real-world signals that can greatly


Source: Amaral, Luis A.N. - Department of Chemical and Biological Engineering, Northwestern University


Collections: Physics; Biology and Medicine