نتایج جستجو برای: ville distribution wvd is another method that has superior tfr resolution
تعداد نتایج: 9485128 فیلتر نتایج به سال:
In this paper the authors will try to discuss the applicability of Wigner-Ville Distribution for the digital analysis of auscultatory sounds. First of all, thte issues related to computer aided diagnosis are presented. Next, the methodology of research is shown and subsequently, the types of sounds are described. Another element of this work is the presentation of issues related to the digital ...
Time-frequency analysis of heart sounds using windowed and smooth windowed Wigner-ville distribution
Heart sounds and murmurs are time-varying signals that would best be analyzed using time-frequency analysis. Windowed Wigner-Ville distribution (WWVD) and smooth windowed Wigner-Ville distribution (SWWVD) are used to obtain the timefiequency representation (TFR) of the signal. Determination of parameter setting of WWVD and SWWVD will eliminate the cross-terms and improve TFR. The accuracy of TF...
employees always concern about losing their job , or in other word , losing their income resources. for this purpose, every government requires strong system for covering these concerns. the unemployment insurance (ui) program’s can be used for achieving this goal. in this thesis, we price ui based on the insurance history of employee and the duration of being unemployed. we use the weibull dis...
An Adaptative Neuro-Fuzzy Inference System (ANFIS) is developed to predict the acoustic form function (FF) for an infinite length cylindrical shell excited perpendicularly to its axis. The Wigner-Ville distribution (WVD) is used like a comparison tool between the calculated FF by the analytical method and that predicted by the neuro-fuzzy technique for a copper tube. During the application of t...
Introduction: To realize noninvasive diagnosis and early diagnosis of coronary heart disease, the study proposes a new time-frequency method for analyzing heart sound signals. This method is based on Choi-Williams Distribution (CWD). Methods: CWD distribution is developed and modified from Wigner Ville distribution (WVD). To solve the problem of cross-term interference existing in WVD there is ...
Most of signals in engineering are nonstationary and time-varying. The Fourier transform as a traditional approach can only provide the feature information in frequency domain. The time-frequency techniques may give a comprehensive description of signals in time-frequency planes. Based on some typical nonstationary signals, five time-frequency analysis methods, i.e., the short-time Fourier tran...
In process of AC square wave submerged arc welding, electric signal waveform determines the arc energy characteristics in the time and frequency domain, which also reflects the arc stability of welding proc ess and quality indirectly. Using Wigner-Ville distribution (WVD), time frequency analysis is conducted to the current signal of AC square wave submerged arc welding. The Pseudo Wigner-Ville...
The Wigner-Ville Distribution (WVD) is a promising method for analyzing frequency variations in seismic signals, including those of interest for structural monitoring. Nonlinearities in the force displacement relationship will temporarily decrease the apparent natural frequencies of structures during strong to moderate excitation, and earthquake damage can permanently change building stiffnesse...
OBJECTIVES This review outlines the methodological fundamentals of the most frequently used non-parametric time-frequency analysis techniques in biomedicine and their main properties, as well as providing decision aids concerning their applications. METHODS The short-term Fourier transform (STFT), the Gabor transform (GT), the S-transform (ST), the continuous Morlet wavelet transform (CMWT), ...
امروزه تخمین حرکت بلوک در تصاویر بر اساس روش هایی که تمام جزئیات را شامل می شوند، تبدیل به یک مبحث فراگیر در شاخه ی پردازش تصویر گشته است. چرا که از جمله ی روش هایی به حساب می آید که باعث فشردگی و کاهش حجم داده های تصویری می گردد. جهت تحقّق این هدف، الگوریتم های متفاوتی ارائه شده اند. الگوریتم های جستجوی محلی، جستجوی پیشگویانه و... که با توجه به نیاز مسأله انتخاب و مورد استفاده قرار می گیرند، از...
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