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Zsigmond Tarcsay - One of the best experts on this subject based on the ideXlab platform.

Judit Abardia - One of the best experts on this subject based on the ideXlab platform.

Andreas Bernig - One of the best experts on this subject based on the ideXlab platform.

Reinhold Haeb-umbach - One of the best experts on this subject based on the ideXlab platform.

  • Blind speech separation employing directional statistics in an Expectation Maximization framework
    2010 IEEE International Conference on Acoustics Speech and Signal Processing, 2010
    Co-Authors: Dang Hai Tran Vu, Reinhold Haeb-umbach
    Abstract:

    In this paper we propose to employ directional statistics in a Complex Vector Space to approach the problem of blind speech separation in the presence of spatially correlated noise. We interpret the values of the short time Fourier transform of the microphone signals to be draws from a mixture of Complex Watson distributions, a probabilistic model which naturally accounts for spatial aliasing. The parameters of the density are related to the a priori source probabilities, the power of the sources and the transfer function ratios from sources to sensors. Estimation formulas are derived for these parameters by employing the Expectation Maximization (EM) algorithm. The E-step corresponds to the estimation of the source presence probabilities for each time-frequency bin, while the M-step leads to a maximum signal-to-noise ratio (MaxSNR) beamformer in the presence of uncertainty about the source activity. Experimental results are reported for an implementation in a generalized sidelobe canceller (GSC) like spatial beamforming configuration for 3 speech sources with significant coherent noise in reverberant environments, demonstrating the usefulness of the novel modeling framework.

Adriaan C. Zaanen - One of the best experts on this subject based on the ideXlab platform.

  • Normed Riesz Spaces and Banach Lattices
    Introduction to Operator Theory in Riesz Spaces, 1997
    Co-Authors: Adriaan C. Zaanen
    Abstract:

    Let V be a real or Complex Vector Space and assume that to each element f ∈ V there is assigned a real number ‖ f ‖ such that

  • Complex Riesz Spaces
    Introduction to Operator Theory in Riesz Spaces, 1997
    Co-Authors: Adriaan C. Zaanen
    Abstract:

    All Riesz Spaces in the preceding sections are real Riesz Spaces. We shall now define Complex Riesz Spaces and then extend a considerable part of the theory to these Complex Spaces. Recall first that the Cartesian product X × Y of the non-empty sets X and Y is the set of all ordered pairs (x, y) such that x ∈ X and y ∈ Y. In the case that X = Y = V, where V is a real Vector Space, we can equip the Cartesian product V × V with a Vector Space structure by defining $$ \left( {{f_1},{g_1}} \right) + \left( {{f_2},{g_2}} \right) = \left( {{f_1} + {f_2},{g_1} + {g_2}} \right), $$ $$ \left( {\alpha + i\beta } \right)\left( {f,g} \right) = \left( {\alpha f - \beta g,\beta f + \alpha g} \right) for\alpha ,\beta real numbers, $$ and the so defined Complex Vector Space is denoted by V + iV. Note that (f,0) + (g,0) = (f + g,0) and α(f,0)=(αf,0) for α real. Hence, identifying f ∈ V and (f,0)∈ V + iV, the Space V is embedded in V + iV as a real-linear subSpace. Note also that i(g, 0) = (0, g) by the above definition, so $$ \left( {f,g} \right) = \left( {f,0} \right) + \left( {0,g} \right) = \left( {f,0} \right) + i\left( {g,0} \right). $$