Biomedical subjects

L Rebollo-Neira

Publications and source records attributed to L Rebollo-Neira.

4 recordsLinked to original sources

PubMed2004

Constructive approximations to the q=1/2 maximum entropy distribution from redundant and noisy data.

The problem of constructing the q=1/2 nonextensive maximum entropy distributions from redundant and noisy data is considered. A strategy is proposed, which evolves through the following steps. (i) Independent constraints are first preselected by recourse to a data-independent technique to be discussed here. (ii) The data are a posteriori used to determine the parameters of the distribution by a previously introduced forward approach. (iii) A backward approach is proposed for reducing the parameters of such distribution. The previously introduced forward approach is generalized here in order to make it suitable for dealing with very noisy data.

Journal Article↗

PubMed2002

Recursive approach for constructing the q=1/2 maximum entropy distribution from redundant data.

A recursive approach for computing the q=1/2 nonextensive maximum entropy distribution of the previously introduced formalism for data subset selection is proposed. Such an approach is based on an iterative biorthogonalization technique, which allows for the incorporation of the Lagrange multipliers that determine the distribution to the workings of the algorithm devised for selecting relevant data subsets. This technique circumvents the necessity of inverting operators and yields a recursive procedure to appropriately modify the Lagrange multipliers so as to account for each new constraint.

Journal Article↗

PubMed2001

Nonextensive maximum-entropy-based formalism for data subset selection.

A method for data subset selection, which is based on the q=1 / 2 maximum information measure formalism, is proposed. The method evolves iteratively by selecting, at each iteration, the measure yielding a q=1 / 2 distribution capable of making predictions minimizing the Euclidean distance to the available data.

Journal Article↗

PubMed2000

Frame-theory-based approach for determining the time-frequency distribution characterizing a dense group of reflecting objects

An inverse-scattering problem concerning the determination of a time-frequency spreading function is addressed. Such a function characterizes a dense group of reflecting objects at different ranges and moving with different velocities. The problem, arising in radar and other remote-sensing techniques, is a classical inverse problem. The aim is to reconstruct a function of two variables by means of signals (of one variable) reflected from the environment being observed. The proposed approach is developed by recourse to the frame theory in order to provide a reconstruction formula that asymptotically converges to a unique spreading function. The realistic situation with respect to the transmission of a finite number of signals is further considered. In this case the reconstruction formula is shown to yield the orthogonal projection of the spreading function onto a subspace generated by the outgoing signals.

Journal Article↗