A new distance measure for model-based sequence clustering

We review the existing alternatives for defining model-based distances for clustering sequences and propose a new one based on the Kullback-Leibler divergence. This distance is shown to be especially useful in combination with spectral clustering. For improved performance in real-world scenarios, a model selection scheme is also proposed.Publicad

Boosting Support Vector Machines

En este artículo, se presenta un algoritmo de clasificación binaria basado en Support Vector Machines (Máquinas de Vectores de Soporte) que combinado apropiadamente con técnicas de Boosting consigue un mejor desempeño en cuanto a tiempo de entrenamiento y conserva características similares de generalización con un modelo de igual complejidad pero de representación más compacta./ In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation

Agrupación robusta de Bancos en Argentina

The purpose of this paper is to classify and characterize 64 banks, active as of 2010 in Argentina, by means of robust techniques used on information gathered during the period 2001-2010. Based on the strategy criteria established in (Wang 2007) and (Werbin 2010), seven variables were selected. In agreement with bank theory, four “natural” clusters were obtained, named “Personal”, “Commercial”, “Typical” and “Other banks”. In order to understand this grouping, projection pursuit based robust principal component analysis was conducted on the whole set showing that essentially three variables can be attributed the formation of different clusters. In order to reveal each group inner structure, we used R package mclust to fit a finite Gaussian mixture to the data. This revealed approximately a similar component structure, granting a common principal components analysis as in (Boente and Rodrigues, 2002). This allowed us to identify three variables which suffice for grouping and characterizing each cluster. Boente’s influence measures were used to detect extreme cases in the common principal components analysis.El propósito de este documento es clasificar y caracterizar 64 bancos, activos en 2010 en la Argentina, mediante técnicas robustas utilizadas con información para el período 2001-2010. En base a los criterios de estrategia establecidos en (Wang 2007) y (Werbin 2010), se seleccionaron siete variables. De acuerdo con la teoría bancaria, se obtuvieron cuatro conglomerados "naturales", denominados "Personal", "Comercial", "Típico" y "Otros bancos". Para comprender este agrupamiento, se utilizó el todo el conjunto de banco y se realizó un análisis de los componentes principales basado en la proyección, que mostró que esencialmente tres variables pueden atribuirse a la formación de diferentes agrupaciones. A fin de revelar la estructura interna de cada grupo, utilizamos el paquete R mclust para ajustar una mezcla gaussiana finita a los datos. Esto reveló aproximadamente una estructura de componentes similar, lo que garantiza un análisis de componentes principales comunes como en (Boente y Rodrigues, 2002). Esto nos permitió identificar tres variables que son suficientes para agrupar y caracterizar cada cluster. Las medidas de influencia de Boente se utilizaron para detectar casos extremos en el análisis de componentes principales comunes

On the existence threshold for positive solutions of p-laplacian equations with a concave-convex nonlinearity

We study the following boundary value problem with a concave-convex nonlinearity: \begin{equation*} \left\{ \begin{array}{r c l l} -\Delta_p u & = & \Lambda\,u^{q-1}+ u^{r-1} & \textrm{in }\Omega, \\ u & = & 0 & \textrm{on }\partial\Omega. \end{array}\right. \end{equation*} Here $\Omega \subset \mathbb{R}^n$ is a bounded domain and $1<q<p<r<p^*$. It is well known that there exists a number $\Lambda_{q,r}>0$ such that the problem admits at least two positive solutions for $0<\Lambda<\Lambda_{q,r}$, at least one positive solution for $\Lambda=\Lambda_{q,r}$, and no positive solution for $\Lambda > \Lambda_{q,r}$. We show that $$\lim_{q \to p} \Lambda_{q,r} = \lambda_1(p),$$ where $\lambda_1(p)$ is the first eigenvalue of the p-laplacian. It is worth noticing that $\lambda_1(p)$ is the threshold for existence/nonexistence of positive solutions to the above problem in the limit case $q=p$

Aspectos penales de la clonacion humana terapeutica.

72 p.La clonación humana terapéutica consiste en transferir el núcleo de una célula somática diferenciada al citoplasma de un ovocito previamente enucleado. Se produce así un cigoto humano manteniéndolo hasta el estado de blastocisto, para luego, destruirlo y extraer de él sus células troncales. Éstas tienen la propiedad de transformarse en cualquier tejido u órgano humano, posibilitando el tratamiento de enfermedades producidas por muerte celular como Alzheimer, Parkinson, esclerosis múltiple, lesiones medulares, osteoporosis, etc. El problema es la destrucción de una vida humana utilizándola como objeto. Esto tiene repercusiones éticas, morales, y jurídicas, atendiendo el atropello de la vida y la dignidad humana. Un pronunciamiento jurídico prohibitivo evitaría el abuso de una vida en formación. Necesariamente deben estudiarse alternativas mediante las cuales se puedan lograr los avances científicos que se persiguen para una mejor calidad de vida de todos sin transar la vida de un ser humano

Manipulacion genetica con fines no pacificos, las armas biológicas en el derecho internacional y comparado y situación actual de la legislación chilena respecto al tema.

70 p.El objetivo fundamental de la presente memoria es entregar un cuerpo sistemático sobre la situación de las armas biológicas en la actualidad tanto en el plano internacional como nacional dada la falta de textos que se refieran al tema a cabalidad. En este breve trabajo de investigación se abordarán temas que van desde aspectos biológicos hasta el rol que el derecho cumple en la regulación de las conductas relacionadas con armas biológicas. Para ello se analizará con mayor profundidad que otras normas, la convención sobre armas biológicas, principal regulación internacional respecto al tema. Asimismo se mencionarán normas del derecho comparado, finalizando con un análisis de las normas internas pertinentes. Los resultados obtenidos nos llevaron a concluir que existe mucho por hacer respecto al tema, dado los avances vertiginosos que experimentan cada día la Biotecnología e Ingeniería Genética, jugando un rol fundamental, los ordenamientos jurídicos internos de cada país

Theoretical study of structural and electronic properties of 2H-phase transition metal dichalcogenides

Computational physics and chemistry are called to play a very important role in the development of new technologies based on two-dimensional (2D) materials, reducing drastically the number of trial and error experiments needed to obtain meaningful advances in the field. Here, we present a thorough theoretical study of the structural and electronic properties of the single-layer, double-layer, and bulk transition metal dichalcogenides MoS2, MoSe2, MoTe2, WS2, WSe2, and WTe2 in the 2H phase, for which only partial experimental information is available. We show that the properties of these systems depend strongly on the density functional theory approach used in the calculations and that inclusion of weak dispersion forces is mandatory for a correct reproduction of the existing experimental data. By using the most accurate functionals, we predict interlayer separations, direct and indirect band gaps, and spin-orbit splittings in those systems for which there is no experimental information available. We also discuss the variation of these properties with the specific chalcogen and transition metal ato

A Video-Aware FEC-Based Unequal Loss Protection System for Video Streaming over RTP

A video-aware unequal loss protection (ULP) system for protecting RTP video streaming in bursty packet loss networks is proposed. Considering the relevance of the frame, the state of the channel, and the bitrate constraints of the protection bitstream, our algorithm selects in real time the most suitable frames to be protected through forward error protection (FEC) techniques. It benefits from a wise RTP encapsulation that allows working at a frame level without requiring any further process than that of parsing RTP headers. This makes our system straightforward and fast, perfectly suitable to be included in commercial video streaming servers. Simulation results show how our technique outperforms other proposed ULP schemes

Application-Layer FEC Scheme Configuration Optimization via Hybrid Simulated Annealing

An optimization technique based on an adapted combination of simulated annealing (SA) and tabu search (TS) is presented. This method aims at finding near-optimal unequal error protection (UEP) application-layer FEC code configurations. This approach is intended to smartly protect audio and video transmission over IP networks when hard time restrictions apply. The considered code is a UEP version of the widely-used Pro-MPEG COP3 codes enabling the use of several matrices of dissimilar size and thus of unequal recovery capability. Finding the optimal configuration frequently requires the evaluation of a large solution space. So, to fulfill the imposed constraints, SA is adapted to the specifics of the scenario. In particular, the annealing schedule is conditioned by the real-time restrictions. Furthermore, solution neighborhood structures are determined by a proposed definition of distance between protection configurations, which, jointly with TS, conditions the selection of candidate solutions. Experimental results show a significantly improved performance of the optimization process, which invariably fulfills imposed timing constraints, at the expense of a very low distortion increase, when compared to using exhaustive search. These results allow the use of UEP Pro-MPEG COP3 codes for protecting video and audio transmission, which distinctly outperforms the standard code in a wide range of scenarios