Prácticas educativas universitarias en entornos digitales 2.0

Hoy en día, el elenco de aplicaciones relacionadas con la web 2.0 es muy amplia y pueden ofrecer en el ámbito educativo nuevos espacios para la comunicación, colaboración, imaginación y creación de comunidades de conocimientos compartidos. El presente estudio presenta una experiencia innovadora con tecnologías digitales 2.0 realizado en la Universidad de Extremadura durante el curso académico 2008-09. Entre las finalidades educativas resaltan: fomentar el papel protagonista del estudiante universitario como agente dinamizador y gestor del conocimiento. Uso y utilización de los blogs como recurso docente. Y desarrollar un espacio de reflexión sobre el concepto de Unidad Didáctica. Como conclusión al estudio se ha comprobado que los blogs son fáciles de elaborar y utilizar, favorece el papel activo de los estudiantes, son un recurso importante para formación del profesorado y un instrumento pedagógico para difundir conocimientos y experiencias educativas.Today, the tools of applications related to Web 2.0 are very broad and can offer on the new educational spaces for communication, collaboration, imagination and create communities of shared knowledge. This study presents an innovative experience with digital technologies 2.0 held at the University of Extremadura during the academic year 2008-09. Among the highlights educational aims: to promote the central role of student as dynamic agent and knowledge manager. Use of blogs as a teaching resource. And developing a space for reflection about learning resources. In conclusion the study found that blogs are easy to create and use, supports the active role of students, are an important tool for teacher training and an educational tool to disseminate knowledge and educational skills

A new similarity function for generalized trapezoidal fuzzy numbers

Numerous authors have proposed functions to quantify the degree of similarity between two fuzzy numbers using various descriptive parameters, such as the geometric distance, the distance between the centers of gravity or the perimeter. However, these similarity functions have drawback for specific situations. We propose a new similarity measure for generalized trapezoidal fuzzy numbers aimed at overcoming such drawbacks. This new measure accounts for the distance between the centers of gravity and the geometric distance but also incorporates a new term based on the shared area between the fuzzy numbers. The proposed measure is compared against other measures in the literature

Searching for a consensus similarity function for generalized trapezoidal fuzzy numbers

There is controversy regarding the use of the similarity functions proposed in the literature to compare generalized trapezoidal fuzzy numbers since conflicting similarity values are sometimes output for the same pair of fuzzy numbers. In this paper we propose a similarity function aimed at establishing a consensus. It accounts for the different approaches of all the similarity functions. It also has better properties and can easily incorporate new parameters for future improvements. The analysis is carried out on the basis of a large and representative set of pairs of trapezoidal fuzzy numbers

A Fuzzy approach based on dynamic programming and metaheuristics for selecting safeguards for risk management for information systems

In this paper we focus on the selection of safeguards in a fuzzy risk analysis and management methodology for information systems (IS). Assets are connected by dependency relationships, and a failure of one asset may affect other assets. After computing impact and risk indicators associated with previously identified threats, we identify and apply safeguards to reduce risks in the IS by minimizing the transmission probabilities of failures throughout the asset network. However, as safeguards have associated costs, the aim is to select the safeguards that minimize costs while keeping the risk within acceptable levels. To do this, we propose a dynamic programming-based method that incorporates simulated annealing to tackle optimizations problems

Elicitación de probabilidades difusas

En este trabajo exponemos un método interactivo cuyo objetivo es extraer de los expertos un número difuso que indique la probabilidad subjetiva de un suceso. Este método, basado en los clásicos métodos de apuestas y loterías para la elicitación de probabilidades, evita el uso de escalas de términos lingüísticos representados por números difusos con amplitud de soporte y simetría previamente establecidos, permitiendo a cada experto una mayor o menor precisión y libertad en el establecimiento de sus juicios probabilísticos. Además, establecemos una función que mide la calidad del juicio probabilístico expresado mediante la agregación de dos componentes que miden la coherencia y la precisión mostrada por el experto durante el proceso de educción

An interactive method of fuzzy probability elicitation in risk analysis

Expert knowledge is used to assign probabilities to events in many risk analysis models. However, experts sometimes find it hard to provide specific values for these probabilities, preferring to express vague or imprecise terms that are mapped using a previously defined fuzzy number scale. The rigidity of these scales generates bias in the probability elicitation process and does not allow experts to adequately express their probabilistic judgments. We present an interactive method for extracting a fuzzy number from experts that represents their probabilistic judgments for a given event, along with a quality measure of the probabilistic judgments, useful in a final information filtering and analysis sensitivity process

A fuzzy extension of MAGERIT methodology for risk analysis in information systems

We propose a fuzzy approach to deal with risk analysis for information systems. We extend MAGERIT methodology that valuates the asset dependencies to a fuzzy framework adding fuzzy linguistic terms to valuate the different elements (terminal asset values, asset dependencies as well as the probability of threats and the resulting asset degradation) in risk analysis. Computations are based on the trapezoidal fuzzy numbers associated with these linguistic terms and, finally, the results of these operations are translated into a linguistic term by means of a similarity function

Análisis de riesgos en los sistemas de información: un enfoque difuso

En los modelos promovidos por las normativas internacionales de análisis de riesgos en los sistemas de información, los activos están interrelacionados entre sí, de modo que un ataque sobre uno de ellos se puede transmitir a lo largo de toda la red, llegando a alcanzar a los activos más valiosos para la organización. Es necesario entonces asignar el valor de todos los activos, así como las relaciones de dependencia directas e indirectas entre estos, o la probabilidad de materialización de una amenaza y la degradación que ésta puede provocar sobre los activos. Sin embargo, los expertos encargados de asignar tales valores, a menudo aportan información vaga e incierta, de modo que las técnicas difusas pueden ser muy útiles en este ámbito. Pero estas técnicas no están libres de ciertas dificultades, como la necesidad de uso de una aritmética adecuada al modelo o el establecimiento de medidas de similitud apropiadas. En este documento proponemos un tratamiento difuso para los modelos de análisis de riesgos promovidos por las metodologías internacionales, mediante el establecimiento de tales elementos.Abstract— Assets are interrelated in risk analysis methodologies for information systems promoted by international standards. This means that an attack on one asset can be propagated through the network and threaten an organization’s most valuable assets. It is necessary to valuate all assets, the direct and indirect asset dependencies, as well as the probability of threats and the resulting asset degradation. However, the experts in charge to assign such values often provide only vague and uncertain information. Fuzzy logic can be very helpful in such situation, but it is not free of some difficulties, such as the need of a proper arithmetic to the model under consideration or the establishment of appropriate similarity measures. Throughout this paper we propose a fuzzy treatment for risk analysis models promoted by international methodologies through the establishment of such elements

A fuzzy approach to risk analysis in information systems

Assets are interrelated in risk analysis methodologies for information systems promoted by international standards. This means that an attack on one asset can be propagated through the network and threaten an organization's most valuable assets. It is necessary to valuate all assets, the direct and indirect asset dependencies, as well as the probability of threats and the resulting asset degradation. These methodologies do not, however, consider uncertain valuations and use precise values on different scales, usually percentages. Linguistic terms are used by the experts to represent assets values, dependencies and frequency and asset degradation associated with possible threats. Computations are based on the trapezoidal fuzzy numbers associated with these linguistic terms

Complicity functions for detecting organized crime rings

Graph theory is an evident paradigm for analyzing social networks, which are the main tool for collective behavior research, addressing the interrelations between members of a more or less well-defined community. Particularly, social network analysis has important implications in the fight against organized crime, business associations with fraudulent purposes or terrorism. Classic centrality functions for graphs are able to identify the key players of a network or their intermediaries. However, these functions provide little information in large and heterogeneous graphs. Often the most central elements of the network (usually too many) are not related to a collective of actors of interest, such as be a group of drug traffickers or fraudsters. Instead, its high centrality is due to the good relations of these central elements with other honorable actors. In this paper we introduce complicity functions, which are capable of identifying the intermediaries in a group of actors, avoiding core elements that have nothing to do with this group. These functions can classify a group of criminals according to the strength of their relationships with other actors to facilitate the detection of organized crime rings. The proposed approach is illustrated by a real example provided by the Spanish Tax Agency, including a network of 835 companies, of which eight were fraudulent