On the Localization of the Personalized PageRank of Complex Networks

In this paper new results on personalized PageRank are shown. We consider directed graphs that may contain dangling nodes. The main result presented gives an analytical characterization of all the possible values of the personalized PageRank for any node.We use this result to give a theoretical justification of a recent model that uses the personalized PageRank to classify users of Social Networks Sites. We introduce new concepts concerning competitivity and leadership in complex networks. We also present some theoretical techniques to locate leaders and competitors which are valid for any personalization vector and by using only information related to the adjacency matrix of the graph and the distribution of its dangling nodes

El impacto de la gamificación como técnica en el proceso de enseñanza/aprendizaje de una lengua extranjera en Educación Primaria

El presente estudio de investigación, que se ha llevado a cabo durante el periodo del Practicum, concretamente en el mes de Abril, trata de comprobar cómo responde el alumnado del segundo curso de Educación Primaria ante el proceso de enseñanza/aprendizaje de una lengua extranjera mediante el uso de la metodología de gamificación. Lo que se pretende conseguir es que este tipo de técnica afecte a la motivación, a la concentración, al esfuerzo y a la participación del alumnado de manera positiva en el aprendizaje de un nuevo idioma. Para ello la investigación se ha llevado a cabo en tres partes: la primera se basa en la recogida de datos, la segunda en la puesta en práctica de la técnica y la tercera en extraer conclusiones propias.Grado en Educación Primari

Divulgación de información sobre riesgos y coste de los recursos propios: un enfoque bayesiano

El objetivo de este artículo es analizar la relación entre la divulgación de información sobre riesgo y el coste de capital de los recursos propios de empresas que cotizan en el mercado de capitales español. Este estudio utiliza un conjunto de 71 empresas que cotizaron en la Bolsa de Madrid entre 2010 y 2015; todas son empresas no financieras de las que había previsiones de beneficios. El problema se ha analizado bajo un enfoque de regresión lineal Bayesiana. Los resultados del estudio muestran que el coste de capital de los recursos propios y la información de riesgo divulgada no están relacionados cuando se toma la información de riesgos de manera global. Sin embargo, cuando la información de riesgo se divide en riesgos financieros y no financieros, se encuentra una relación positiva entre los riesgos financieros y el coste de capital de los recursos propios.This paper aims to analyze the relationship between risk information disclosure and the cost of equity of companies in the Spanish capital market. This study uses a set of 71 firms listed on Madrid stock exchange between 2010 and 2015; all of them are non-financial listed companies for which profit forecasts existed. The problem was analyzed using a Bayesian linear regression approach. The results show that cost of equity and disclosed risk information are not related if a global view of the latter is adopted. However, a positive relationship between financial risks and the cost of equity occurs when risk information is divided into financial and non-financial risks

A multi-ion beam microanalysis approach for the characterization of plasma polymerized allylamine films

EPJ Applied Physics 56. 2 (2011): 24021 with kind permission of The European Physical Journal (EPJ)A full characterization of plasma polymerized biofunctional films requires the use of multi-analytical approaches to determine the chemical composition, topography and potential interaction mechanisms of such films with biomolecules and cells. In this work we aim at underlining the versatility of ion-based techniques to contribute to the chemical characterization of plasma polymerized surfaces. The simultaneous use of energy recoil detection (ERD) and Rutherford backscattering (RBS) spectroscopies with incident He ions is an example of this versatility. Performing sequential measurements and the use of correlating computing tools for ERD-RBS interpretation allows providing in-depth concentration profiles of light elements, including namely hydrogen. More accurate analysis of light elements in polymer films can be increased by looking for particular ions with resonant backscattering responses (i.e., non-Rutherford Scattering). In particular, proton beams of 1.765 MeV are used to increase the detection of C and N, and particular incidence and detector angles to diminish the Si substrate contribution. These analytical tools have been applied to allylamine films and multi-layers crosslinked in a capacitive plasma onto both Si and porous Si substratesWe acknowledge MICINN funding provided by Grant No. MAT2008-06858-C02-01 and grant from Fundación Domingo Martíne

Probabilistic Bounds on the Length of a Longest Edge in Delaunay Graphs of Random Points in d-Dimensions

Motivated by low energy consumption in geographic routing in wireless networks, there has been recent interest in determining bounds on the length of edges in the Delaunay graph of randomly distributed points. Asymptotic results are known for random networks in planar domains. In this paper, we obtain upper and lower bounds that hold with parametric probability in any dimension, for points distributed uniformly at random in domains with and without boundary. The results obtained are asymptotically tight for all relevant values of such probability and constant number of dimensions, and show that the overhead produced by boundary nodes in the plane holds also for higher dimensions. To our knowledge, this is the first comprehensive study on the lengths of long edges in Delaunay graphsComment: 10 pages. 2 figures. In Proceedings of the 23rd Canadian Conference on Computational Geometry (CCCG 2011). Replacement of version 1106.4927, reference [5] adde

Estimating Sample Size for Usability Testing

One strategy used to assure that an interface meets user requirements is to conduct usability testing. When conducting such testing one of the unknowns is sample size. Since extensive testing is costly, minimizing the number of participants can contribute greatly to successful resource management of a project. Even though a significant number of models have been proposed to estimate sample size in usability testing, there is still not consensus on the optimal size. Several studies claim that 3 to 5 users suffice to uncover 80% of problems in a software interface. However, many other studies challenge this assertion. This study analyzed data collected from the user testing of a web application to verify the rule of thumb, commonly known as the “magic number 5”. The outcomes of the analysis showed that the 5-user rule significantly underestimates the required sample size to achieve reasonable levels of problem detection

Greenways: physical activity, nature and culture

Resumen basado en el de la publicaciónSe parte del estudio de un trabajo fin de master dentro del master de Educador/a Ambiental en la Universidad de Almería y se adelantan algunas cuestiones del proyecto de tesis a desarrollar que dará continuidad al estudio iniciado. Se indaga, desde la perspectiva narrativa, las concepciones y significados en torno al uso de las Vías Verdes y las posibilidades de desarrollo en diversos ámbitos, en especial, en el de la actividad física en el medio natural. Se plantea la vinculación del campo de estudio de la actividad física con la educación ambiental; y vincular el espacio natural a cuestiones sociales, culturales, educativas y deportivas adquiriendo un significado relevante desde la perspectiva educativa ambiental, profundizando en las aportaciones obtenidas en el estudio piloto. La tesis doctoral se enmarca en el paradigma cualitativo y en el uso de herramientas etnográficas para la obtención de información (entrevistas y observación participante), desde la perspectiva narrativa.ES