1,721,180 research outputs found
Blind audio source separation with minimum-volume beta-divergence NMF
No full textConsidering a mixed signal composed of various audio sources and recorded with a single microphone, we consider in this paper the blind audio source separation problem which consists in isolating and extracting each of the sources. To perform this task, nonnegative matrix factorization (NMF) based on the Kullback-Leibler and Itakura-Saito β-divergences is a standard and state-of-the-art technique that uses the time-frequency representation of the signal. We present a new NMF model better suited for this task. It is based on the minimization of β-divergences along with a penalty term that promotes the columns of the dictionary matrix to have a small volume. Under some mild assumptions and in noiseless conditions, we prove that this model is provably able to identify the sources. In order to solve this problem, we propose multiplicative updates whose derivations are based on the standard majorization-minimization framework. We show on several numerical experiments that our new model is able to obtain more interpretable results than standard NMF models. Moreover, we show that it is able to recover the sources even when the number of sources present into the mixed signal is overestimated. In fact, our model automatically sets sources to zero in this situation, hence performs model order selection automatically
Accelerating nonnegative matrix factorization algorithms using extrapolation
No full textWe propose a general framework to accelerate significantly the algorithms for nonnegative matrix factorization (NMF). This framework is inspired from the extrapolation scheme used to accelerate gradient methods in convex optimization and from the method of parallel tangents. However, the use of extrapolation in the context of the exact coordinate descent algorithms tackling the nonconvex NMF problems is novel. We illustrate the performance of this approach on two state-of-the-art NMF algorithms: accelerated hierarchical alternating least squares and alternating nonnegative least squares, using synthetic, image, and document data sets
Algorithms and comparisons of nonnegative matrix factorizations with volume regularization for hyperspectral unmixing
No full textIn this paper, we consider nonnegative matrix factorization (NMF) with a regularization that promotes small volume of the convex hull spanned by the basis matrix. We present highly efficient algorithms for three different volume regularizers, and compare them on endmember recovery in hyperspectral unmixing. The NMF algorithms developed in this paper are shown to outperform the state-of-The-Art volume-regularized NMF methods, and produce meaningful decompositions on real-world hyperspectral images in situations where endmembers are highly mixed (no pure pixels). Furthermore, our extensive numerical experiments show that when the data is highly separable, meaning that there are data points close to the true endmembers, and there are a few endmembers, the regularizer based on the determinant of the Gramian produces the best results in most cases. For data that is less separable and/or contains more endmembers, the regularizer based on the logarithm of the determinant of the Gramian performs best in general.</p
Séparation aveugle de sources sonores par factorization en matrices positives avec pénalité sur le volume du dictionnaire
No full textAudio source separation concerns techniques used to extract unknown signals called sources from a mixed signal. In this paper, we assume that the audio signal is recorded with a single microphone. Considering a mixed signal composed of various audio sources, the blind audio source separation consists in isolating and extracting each of the sources on the basis of a single recording. Usually, the only known information is the number of estimated sources present in the mixed signal. Based on a time-frequency representation of the signal, classical source separation techniques integrate algorithms such as nonnegative matrix factorization (NMF). Optimization problems in blind audio source separation are based on the minimization of criteria such as the Kullback-Leibler and Itakura-Saito divergences, both divergences belonging to the family of β-divergences. In this paper, we present a new model of separation based on the minimization of the Kullback-Leibler includinga penalty term promoting the columns of the dictionary matrix to have small volume. In order to solve this problem, the global cost function is replaced by a convex and separable auxiliary function that will be minimized. We will show that we obtain more interpretable results in the case where the factorization rank (that is, the number of sources present into the mixed signal) is overestimated
Accelerating approximate nonnegative canonical polyadic decomposition using extrapolation
No full textVolume regularized non-negative matrix factorizations
No full textThis work considers two volume regularized non-negative matrix factorization (NMF) problems that decompose a nonnegative matrix X into the product of two nonnegative matrices W and H with a regularization on the volume of the convex hull spanned by the columns of W. This regularizer takes two forms: the determinant (det) and logarithm of the determinant (logdet) of the Gramian of W. In this paper, we explore the structure of these problems and present several algorithms, including a new algorithm based on an eigenvalue upper bound of the logdet function. Experimental results on synthetic data show that (i) the new algorithm is competitive with the standard Taylor bound, and (ii) the logdet regularizer works better than the det regularizer. We also illustrate the applicability of the new algorithm on the San Diego airport hyperspectral image
Minimum-volume Rank-deficient Nonnegative Matrix Factorizations
No full textIn recent years, nonnegative matrix factorization (NMF) with volume regularization has been shown to be a powerful identifiable model; for example for hyperspectral unmixing, document classification, community detection and hidden Markov models. In this paper, we show that minimum-volume NMF (min-vol NMF) can also be used when the basis matrix is rank deficient, which is a reasonable scenario for some real-world NMF problems (e.g., for unmixing multispectral images). We propose an alternating fast projected gradient method for min-vol NMF and illustrate its use on rank-deficient NMF problems; namely a synthetic data set and a multispectral image
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Accelerating block coordinate descent for nonnegative tensor factorization
No full textThis paper is concerned with improving the empirical convergence speed of block-coordinate descent algorithms for approximate nonnegative tensor factorization (NTF). We propose an extrapolation strategy in-between block updates, referred to as heuristic extrapolation with restarts (HER). HER significantly accelerates the empirical convergence speed of most existing block-coordinate algorithms for NTF, in particular for challenging computational scenarios, while requiring a negligible additional computational budget
- …
