Spectral analysis is an important signal processing tool for seismic data. The transformation of a seismogram into the frequency domain is the basis for a significant number of processing algorithms and interpretive methods. However, for seismograms whose frequency content vary with time, a simple 1-D (Fourier) frequency transformation is not sufficient. Improved spectral decomposition in frequ...

Many signals from the physical world can be modeled accurately as a superposition of amplitude-and frequency-modulated waves. This includes audio signals (speech, music), medical data (ECG) aswell as temporal series (temperature or electric consumption). This thesis deals with the analysis of suchsignals, called multicomponent because they contain several modes. The techniques i...

Abstract The reconstruction mechanisms built by the human auditory system during sound are still a matter of debate. purpose this study is to propose mathematical model based on functional architecture cortex (A1). inspired geometrical modelling vision, which has undergone great development in last ten years. There are, however, fundamental dissimilarities, due different role played time and gr...

In this short note, we study all-or-nothing transforms, which were recently proposed by Rivest as a mode of operation for block ciphers. We study transforms of this type that provide unconditional security. A simple construction for linear transforms is given, and some existence and non-existence results for general transforms are derived from a combinatorial characterization of these objects.

Abstract In this paper, we study the nonuniform fast Fourier transform with nonequispaced spatial and frequency data (NNFFT) sinc as its application. The computation of NNFFT is mainly based on nodes equispaced frequencies (NFFT). employs two compactly supported, continuous window functions. For fixed nonharmonic bandwidth, show that error $$\sinh$$ <mml:math xmlns:mml="http://www.w3.org/1998/M...

Photoacoustic waves from hemoglobin solutions in dental roots are detected by using a 1064-nm laser and an ultrasonic soft probe based on a composite transducer on the tooth surface. The high-frequency ultrasonic waves are detected from a tooth with a hemoglobin solution in the pulp cavity due to the large heat transfer coefficient and absorption coefficient of hemoglobin. The spectral intensit...