no code implementations • 8 Jan 2021 • Paris V. Giampouras, Athanasios A. Rontogiannis, Eleftherios Kofidis
The so-called block-term decomposition (BTD) tensor model, especially in its rank-$(L_r, L_r, 1)$ version, has been recently receiving increasing attention due to its enhanced ability of representing systems and signals that are composed of \emph{blocks} of rank higher than one, a scenario encountered in numerous and diverse applications.
no code implementations • 5 Oct 2017 • Paris V. Giampouras, Athanasios A. Rontogiannis, Konstantinos D. Koutroumbas
Nowadays, the availability of large-scale data in disparate application domains urges the deployment of sophisticated tools for extracting valuable knowledge out of this huge bulk of information.
no code implementations • 16 Mar 2017 • Paris V. Giampouras, Athanasios A. Rontogiannis, Konstantinos D. Koutroumbas
Estimation of the number of endmembers existing in a scene constitutes a critical task in the hyperspectral unmixing process.
no code implementations • 11 Feb 2016 • Paris V. Giampouras, Athanasios A. Rontogiannis, Konstantinos E. Themelis, Konstantinos D. Koutroumbas
Extracting the underlying low-dimensional space where high-dimensional signals often reside has long been at the center of numerous algorithms in the signal processing and machine learning literature during the past few decades.
no code implementations • 15 Oct 2015 • Spyridoula D. Xenaki, Konstantinos D. Koutroumbas, Athanasios A. Rontogiannis
The first one, called sparse possibilistic c-means, exploits sparsity and can deal well with closely located clusters that may also be of significantly different densities.
no code implementations • 5 Aug 2015 • Spyridoula D. Xenaki, Konstantinos D. Koutroumbas, Athanasios A. Rontogiannis
In this paper, a convergence proof for the recently proposed sparse possibilistic c-means (SPCM) algorithm is provided, utilizing the celebrated Zangwill convergence theorem.
no code implementations • 11 Dec 2014 • Spyridoula D. Xenaki, Konstantinos D. Koutroumbas, Athanasios A. Rontogiannis
Provided that the algorithm starts with a reasonable overestimate of the number of physical clusters formed by the data, it is capable, in principle, to unravel them (a long-standing issue in the clustering literature).
no code implementations • 13 Jan 2014 • Konstantinos E. Themelis, Athanasios A. Rontogiannis, Konstantinos D. Koutroumbas
Recently, a number of mostly $\ell_1$-norm regularized least squares type deterministic algorithms have been proposed to address the problem of \emph{sparse} adaptive signal estimation and system identification.