Time-varying autoregressive spectral estimation for ultrasound attenuation in tissue characterization
نویسندگان
چکیده
منابع مشابه
On Recursive Estimation for Locally Stationary Time Varying Autoregressive Processes
This paper focuses on recursive estimation of locally stationary autoregressive processes. The stability of the model is revisited and uniform results are provided when the time-varying autoregression parameters belong to appropiate smoothness classes. An adequate normalization for the correction term used in the recursive estimation procedure allows for very mild assumptions on the innovations...
متن کاملNonlinear Wavelet Estimation of Time-varying Autoregressive Processes
We consider nonparametric estimation of the parameter functions a i () , i = 1; : : : ; p , of a time-varying autoregressive process. Choosing an orthonormal wavelet basis representation of the functions a i , the empirical wavelet coeecients are derived from the time series data as the solution of a least squares minimization problem. In order to allow the a i to be functions of inhomogeneous ...
متن کاملSequential Parameter Estimation of Time-Varying Non-Gaussian Autoregressive Processes
Parameter estimation of time-varying non-Gaussian autoregressive processes can be a highly nonlinear problem. The problem gets even more difficult if the functional form of the time variation of the process parameters is unknown. In this paper, we address parameter estimation of such processes by particle filtering, where posterior densities are approximated by sets of samples (particles) and p...
متن کاملNonlinear wavelet estimation of time- varying autoregressive processes
R A I N E R DA H L H AU S , 1 M I C H A E L H . N E U M A N N 2 and RAINER VON SACHS 3 Institut fuÈ r Angewandte Mathematik, UniversitaÈ t Heidelberg, Im Neuenheimer Feld 294, D-69120 Heidelberg, Germany. E-mail: [email protected] SFB 373, Humboldt-UniversitaÈ t zu Berlin, Spandauer Strasse 1, D-10178 Berlin, Germany. E-mail: [email protected] Institut de Statistique, U...
متن کاملAdaptive Estimation of Autoregressive Models with Time-varying Variances By
Stable autoregressive models are considered with martingale differences errors scaled by an unknown nonparametric time-varying function generating heterogeneity. An important special case involves structural change in the error variance, but in most practical cases the pattern of variance change over time is unknown and may involve shifts at unknown discrete points in time, continuous evolution...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
سال: 1998
ISSN: 0885-3010
DOI: 10.1109/58.677609