Santa Fe de la Vera Cruz, Argentina
Santa Fe de la Vera Cruz, Argentina

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Schlotthauer G.,National University of Entre Rios | Schlotthauer G.,CONICET | Torres M.E.,National University of Entre Rios | Torres M.E.,University Nac Del Litoral | And 4 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

Empirical mode decomposition (EMD) is an algorithm for signal analysis recently introduced by Huang. It is a completely data-driven non-linear method for the decomposition of a signal into AM - FM components. In this paper two new EMD-based methods for the analysis and classification of pathological voices are presented. They are applied to speech signals corresponding to real and simulated sustained vowels. We first introduce a method that allows the robust extraction of the fundamental frequency of sustained vowels. Its determination is crucial for pathological voice analysis and diagnosis. This new method is based on the ensemble empirical mode decomposition (EEMD) algorithm and its performance is compared with others from the state of the art. As a second EMD-based tool, we explore spectral properties of the intrinsic mode functions and apply them to the classification of normal and pathological sustained vowels. We show that just using a basic pattern classification algorithm, the selected spectral features of only three modes are enough to discriminate between normal and pathological voices. © 2010 Springer-Verlag.

Pilatti V.,University Nac Del Litoral | Pilatti V.,CONICET | Vegetti A.,University Nac Del Litoral | Vegetti A.,CONICET
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2014

The Boutelouinae subtribe is comprised of one monophyletic genus, Bouteloua, with 57 species inhabiting the semi-arid regions of the New World. The inflorescences show significant structural variations, which provides an interesting system to examine their morphological evolution and identify characters and processes that may help to understand the group systematics. The structure of inflorescences was studied in 25 species of Bouteloua. All the species covered under this study have truncated polytelic inflorescences. Structural variations in the inflorescence unit among species may be accounted for by: (1) symmetry of the inflorescence unit, (2) total number of long primary branches, (3) total number of spikelets per branch, (4) number of perfect flowers per spikelet, (5) number of rudimentary flowers, and (6) reproductive system. Homogenization and truncation processes account for the diversity of mature inflorescences that exists in Bouteloua. In this work, we discuss the systematic and taxonomic value of the inflorescence in the Boutelouinae subtribe. © 2014 Elsevier GmbH.

Reutemann A.G.,University Nac Del Litoral | Reutemann A.G.,CONICET | Pilatti V.,University Nac Del Litoral | Pilatti V.,CONICET | And 3 more authors.
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2014

Ascolepis and Lipocarpha, Cyperaceae, have highly reduced reproductive structures and hypogynous scales that are controversially appreciated. Because of this, flowers and spikelets and, thus, inflorescences have been interpreted in different ways, which, in turn, has led to placing the two genera in different tribes. Some authors interpret spikelets in Ascolepis and Lipocarpha as many-flowered and the so-called hypogynous scales as homologous to the lateral scales of Hypolytrum, or consider these scales comparable to a Scirpus bristle. However, many other authors consider spikelets in Lipocarpha and Ascolepis to be a result of a reductional process from a many-flowered cyperoid spikelet to a single-flowered spikelet, where the adaxial and abaxial hypogynous scales may be seen as the respective prophyll and glume of the reduced spikelets. The latest molecular phylogenies of Cyperaceae show both genera nested in the Cyperus clade, forming, in turn, a clade together with the rest of the Cypereae genera having single-flowered spikelets and hypogynous scales. Alternatively, based on this, the scales of uncertain homology that accompany the Ascolepis and Lipocarpha flower might be seen as special reproductive formations, representing a synapomorphy of such clade, instead of relicts of an ancestor with many-flowered spikelets. In view of this, freshly collected inflorescences of Lipocarpha humboldtiana Nees and Ascolepis brasiliensis (Kunth) Benth. ex C. B. Clarke were studied using light and scanning electron microscopy, with the aim of elucidating the nature of the controversially interpreted reproductive structures of these species from a development perspective. Results show that the "hypogynous scales" simply represent vestigial structures derived from the reduction of typical cyperoid spikelets, rather than a perianth part or specialized formations emerging as evolutionary novelties. Two scales are typically generated in both species, one being abaxial and the other adaxial, homologous to a glume and a prophyll, respectively, which contrasts with the eprophyllate condition so far attributed to Ascolepis. In both cases, the inflorescence is a spike of reduced spikelets, and the floral development in L. humboldtiana and in A. brasiliensis follows the general ontogenetic pattern observed in Cyperoideae. These characteristics support the inclusion of both genera in the Cypereae tribe. © 2013 Elsevier GmbH.

Pais C.M.,University Nac Of os | Rufiner H.L.,University Nac Of os | Rufiner H.L.,University Nac Del Litoral | Rufiner H.L.,CONICET
IFMBE Proceedings | Year: 2015

For the processing and analysis of the electrocardiogram (ECG), an increasing number of applications require real-time detection of the most prominent complex in the signal, the QRS. In this work we describe a new robust and on-line QRS detection algorithm. This new approach incorporate some classic concepts but has the distinction of being focused on finding the points of maximal similarity between the signal and an atom previously selected from a wavelet packet based dictionary. The proposed algorithm provides the advantage of robust and efficient QRS detection with relatively low computational effort, enabling real-time implementation on 8-bit microcontrollers for general use. © Springer International Publishing Switzerland 2015.

Ibarrola F.J.,University Nac Del Litoral | Spies R.D.,University Nac Del Litoral | Spies R.D.,CONICET
PANACM 2015 - 1st Pan-American Congress on Computational Mechanics, in conjunction with the 11th Argentine Congress on Computational Mechanics, MECOM 2015 | Year: 2015

The image inpainting problem consists of restoring an image from a possibly noisy version of it, in which data from one or more regions is missing. Over the last couple of decades, several inpainting models to perform this task have been developed. Although some of these models perform reasonably well in certain types of images, quite a few issues are yet to be sorted out. For instance, if the true image is smooth, the inpainting can be performed with very good results by means of a Bayesian approach and a maximum a posteriori computation [1]. For non-smooth images, however, such an approach is far from being satisfactory. Even though the introduction of anisotropy by prior gradient inpainting to the latter methodology is shown to produce satisfactory results for slim missing regions, the quality of the restoration decays as the occlusions widen. On the other hand, Total Variation (TV) inpainting models based on high order PDE diffusion equations can be used whenever edge restoration is a priority. More recently, the introduction of spatially variant conductivity coefficients to these models, such as in the case of Curvature-Driven Diffusions (CDD) [4], has allowed inpainted images with well defined edges and enhanced object conectivity. The CDD approach, nonetheless, is not quite suitable wherever the image is smooth, as it tends to produce piecewise constant restorations. In this work we shall combine the ideas of gradient inpainting for introducing anisotropy along with the notion of isophote curvature into a mixed penalization inpainting model [5] to produce an edge-preserving restoration which also allows for inpainting of smooth areas without precluding object conectivity. Several results will be presented and comparisons will be made in order to illustrate the performance of the different penalizers in conjunction with the corresponding parameter estimation criteria and computing methods.

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