Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: spectogram

Sortuj według:

Ogranicz wyniki do:

Reduction of Cross Terms in Wigner-Ville Distribution of Transiently Evoked Otoacoustic Emission

100%

Grzanka A. , Hatzopoulos S. , Śliwa L. , Muliński W.

tom vol. 49, nr 3

493-503

The objective of the paper is to present a new method of time-frequency representation, applicable on signals of short duration, based on regional smoothing of Wigner-Ville distribution (WYD). The proposed algorithm reduces the amplitude of the cross-terms and preserves high resolution of the WYD, because the smoothing routine is applied only in the regions where cross-terms appear. The criterion for cross-terms localisation is the negativity of energy in the time-frequency plane. The method is energy balanced and does not affect the positive values of the spectrogram. The method has been specially fitted for Transiently Evoked Otoacoustic Emission (TEOAE) signals, whose spectral properties are still under investigation. The presented results show (i) that the TEOAE signals are very complex and (ii) that the application of the proposed method of analysis may decompose the TEOAE signals into components which may contribute more to our understanding of the TEOAE underlying cochlear mechanies.

Time frequency analysis of patent ductus arteriosus disease in dogs

100%

Akgün Ö. , Varol H. S.

tom R. 88, nr 9b

309-313

This study is based on the analysis of the heart sound signals taken from different auscultation areas of three dogs diagnosed with Patent Ductus Arteriosus (PDA). The analyses were started by introducing the mathematical substructure of the methods used. Then the phonocardiographic signals taken from the three dogs were assessed in terms of time-amplitude (t-a) and frequency amplitude (f-a); subsequently, the components of the signals in time-frequency dimensions were examined. As a result of these analyses, the importance of the auscultation area and time-frequency examination in the diagnosis of the PDA disease was demonstrated.

W artykule zaprezentowano analize shgnałów serca z różnych obszarów ciała trzech psów cierpiących na chorobę Patent Ductus Arteriosus. Przeprowadzono analizę harmoniczną sygnałów w dziedzinie czasu.