Analysis and study on text representation to improve the accuracy of the Normalized Compression Distance

The huge amount of information stored in text form makes methods that deal with texts really interesting. This thesis focuses on dealing with texts using compression distances. More specifically, the thesis takes a small step towards understanding both the nature of texts and the nature of compression distances. Broadly speaking, the way in which this is done is exploring the effects that several distortion techniques have on one of the most successful distances in the family of compression distances, the Normalized Compression Distance -NCD-.Comment: PhD Thesis; 202 page

Próceres y heroínas de la independencia : dos modelos de representación de las mujeres en la puesta en escena de la nación colombiana, 1880-1910

Historiador (a)Pregrad

MIRACLE-FI at ImageCLEFphoto 2008: Experiences in merging text-based and content-based retrievals

This paper describes the participation of the MIRACLE consortium at the ImageCLEF Photographic Retrieval task of ImageCLEF 2008. In this is new participation of the group, our first purpose is to evaluate our own tools for text-based retrieval and for content-based retrieval using different similarity metrics and the aggregation OWA operator to fuse the three topic images. From the MIRACLE last year experience, we implemented a new merging module combining the text-based and the content-based information in three different ways: FILTER-N, ENRICH and TEXT-FILTER. The former approaches try to improve the text-based baseline results using the content-based results lists. The last one was used to select the relevant images to the content-based module. No clustering strategies were analyzed. Finally, 41 runs were submitted: 1 for the text-based baseline, 10 content-based runs, and 30 mixed experiments merging text and content-based results. Results in general can be considered nearly acceptable comparing with the best results of other groups. Obtained results from textbased retrieval are better than content-based. Merging both textual and visual retrieval we improve the text-based baseline when applying the ENRICH merging algorithm although visual results are lower than textual ones. From these results we were going to try to improve merged results by clustering methods applied to this image collection

Reducing the loss of information through annealing text distortion

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Granados, A. ;Cebrian, M. ; Camacho, D. ; de Borja Rodriguez, F. "Reducing the Loss of Information through Annealing Text Distortion". IEEE Transactions on Knowledge and Data Engineering, vol. 23, no. 7 pp. 1090 - 1102, July 2011Compression distances have been widely used in knowledge discovery and data mining. They are parameter-free, widely applicable, and very effective in several domains. However, little has been done to interpret their results or to explain their behavior. In this paper, we take a step toward understanding compression distances by performing an experimental evaluation of the impact of several kinds of information distortion on compression-based text clustering. We show how progressively removing words in such a way that the complexity of a document is slowly reduced helps the compression-based text clustering and improves its accuracy. In fact, we show how the nondistorted text clustering can be improved by means of annealing text distortion. The experimental results shown in this paper are consistent using different data sets, and different compression algorithms belonging to the most important compression families: Lempel-Ziv, Statistical and Block-Sorting.This work was supported by the Spanish Ministry of Education and Science under TIN2010-19872 and TIN2010-19607 projects

Isoperimetric inequalities in graphs and surfaces

Let M be the set of metric spaces that are either graphs with bounded degree or Riemannian manifolds with bounded geometry. Kanai proved the quasi-isometric stability of several geometric properties (in particular, of isoperimetric inequalities) for the spaces in M. Kanai proves directly these results for graphs with bounded degree; in order to prove the general case, he uses a graph (an ?-net) associated to a Riemannian manifold with bounded geometry. This paper studies the stability of isoperimetric inequalities under quasi-isometries between non-exceptional Riemann surfaces (endowed with their Poincare metrics). The present work proves the stability of the linear isoperimetric inequality for planar surfaces (genus zero surfaces) without the condition on bounded geometry. It is also shown the stability of any non-linear isoperimetric inequality

Asymptotic Values of Meromorphic Functions of Finite Order.

The asymptotic values of a meromorphic function (of any order) defined in the complex plane form a Suslin analytic set. Moreover, given an analytic set A we construct a meromorphic function of finite order and minimal growth having A as its precise set of asymptotic values

Alteraciones del equilibrio en consumidores de hachis = Balance disturbance in hashish consumers

El cannabis es la droga más consumida a nivel mundial, el 4% de las personas de 15-64 años lo consumen, y el hachís es su forma de presentación más habitual en Europa. En España, la edad media de inicio al consumo de cannabis se sitúa en 14,6 años. El 36.2% de los españoles de 14-18 años lo han consumido alguna vez, siendo de las mayores prevalencias europeas. Este dato debe alarmar a los profesionales de la educación física, ya que el consumo de cannabis entraña un riesgo añadido a sus clases, como demostraremos en este trabajo. La hipótesis que planteamos es: la inhalación de hachís a través de un cigarrillo provoca alteraciones en el equilibrio corporal. Para este estudio, participaron un grupo de consumidores de hachís y otro de no consumidores, observando los efectos de esta droga en su equilibrio. Se realizaron dos mediciones (antes y después del consumo) de las siguientes pruebas: dedo-nariz, Romberg, Unterberger, Babinsky-Weill. Tras analizar e interpretar los datos, se llegó estas conclusiones: Inhalar hachís a través de un cigarrillo altera el equilibrio; Los sujetos que inhalan hachís muestran mayores alteraciones en el equilibrio que los que no lo hacen; Las alteraciones en el equilibrio causadas por el consumo de hachís están asociadas a problemas de neurotransmisión en los ganglios basales y el cerebelo que alteran su función de regulación de la postura y tono muscular. Estas conclusiones confirman la hipótesis señalada y el riesgo que supone el consumo de hachís para la educación física. Cannabis is the most used drug worldwide, near 4% of people from 15 to 64 years old use it, hashis is the most common way to use drugs in Europe. In Spain, the average age of initiation to cannabis use is 14,6 years old. The 36,2% of spanish population from 14 to 18 years old have at least use it once in their lifes, being one of the major european prevalences. This piece of information must alarm to the physical education professionals, because the cannabis use entails an added risk to their classes, as we are going to prove in this work. The hypothesis which we raise is: inhaling hashis through a cigarette causes corporal balance alteration. In this research, two groups take part, one group of hashis consumers and another of non-consumers, observing the results of the use of this drug on their balance. Two measurements were taken (before and after the use) of the following tests: finger-nose, Romberg, Unterberger, Babinsky-Weill. After the data were analyzed an interpreted, this conclusion was reached: to inhale hashis through a cigarrette changes balance; the subjects who inhale hashis show more alteration in balance that those who don´t; the alteration in balance caused by hashis use are related to neurotransmission problems in basal nodes and cerebelum that alter its regulation function of the posture and muscular tone. All these conclusions confirm the pointed hypothesis and the risk hashis entails for physical education