نتایج جستجو برای: time frequency transform
تعداد نتایج: 2342512 فیلتر نتایج به سال:
Buried channels are one of the stratigraphic hydrocarbon traps. They are often filled with a variety of porous and permeable sediments so they are important in the exploration of oil and gas reservoirs. In reflection seismic data, high-frequency components are sensitive to the channel thickness, whereas, low-frequency components are sensitive to the channel infill materials. Therefore, decompos...
S-transform is a new time-frequency analysis method, which is deduced from short-time Fourier transform and continue Wavelet transform. It has much better performance than traditional time-frequency method. Therefore, in this paper, the basic principle of is briefly introduced and the relationships between is analyzed by theoretical derivation. According to the simulation experiments, the time-...
The performance of Hilbert spectrum (HS) in time-frequency representation (TFR) of audio signals is investigated in this paper. HS offers a fine-resolution TFR of time domain signals. It is derived by applying empirical mode decomposition (EMD), a newly developed data adaptive method for nonlinear and non-stationary signal analysis together with Hilbert transform. EMD represents any time domain...
Carrier-free short pulse widely employed in UWB radar is brought into high-resolution sonar system, which has unique advantages: attaining more target information, restraining fluctuation of reverberation envelop efficiently in short-range detection and achieving accurate estimation. In essence such pulse is transiently short in time domain and wide in frequency domain, and as such it is diffic...
In this paper, some time-frequency analysis methods were studied to get the detailed characteristics of two-way automatic communication system (TWACS) outbound signal sampled from industry power network with high disturbance, . Compared with traditional time-domain detecting algorithm, time-frequency analysis methods, including short-time Fourier transform (STFT)), Wigner distribution (WD) and ...
Efficient speech signal representations are prerequisite for efficient speech processing algorithms. The Vandermonde transform is a recently introduced time-frequency transform which provides a sparse and uncorrelated speech signal representation. In contrast, the Fourier transform only decorrelates the signal approximately. To achieve complete decorrelation, the Vandermonde transform is signal...
where w(τ) is a real-valued even lag window. Implementations (hardware and software) of this transform are already widely present in practice. The STFT is linear and very simple for realization. However, it has some serious drawbacks. The most important one lies in its low concentration in the TF plane, when highly nonstationary signals are analyzed. In order to improve TF representation, vario...
We investigate the Weyl calculus of pseudodifferential operators with the methods of time-frequency analysis. As symbol classes we use the modulation spaces, which are the function spaces associated to the short-time Fourier transform and the Wigner distribution. We investigate the boundedness and Schatten-class properties of pseudodifferential operators, and furthermore we study their mapping ...
This paper presents a new method for evaluation and simulation of inrush current in various transformers using operational matrices and Hartley transform. Unlike most of the previous works, time and frequency domain calculations are conducted simultaneously. Mathematical equations are first represented to compute the inrush current based on reiteration and then Hartley transform is used to stud...
Wavelet transforms have recently emerged as a mathematical tool for multiresolution decomposition of signals. They have potential applications in many areas of signal processing that require variable time–frequency localization. The continuous wavelet transform is presented here, and its frequency resolution is derived analytically and shown to depend exclusively on one parameter that should be...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید