A WOWA-based aggregation technique on trust values connected to metadata

Metadata produced by members of a diverse community of peers tend to contain low-quality or even mutually inconsistent assertions. Trust values computed on the basis of users' feedback can improve metadata quality and reduce inconsistency, eliminating untrustworthy assertions. In this paper, we describe an approach to metadata creation and improvement, where community members express their opinions on the trustworthiness of each assertion. Our technique aggregates individual trustworthiness values to obtain a community-wide assessment of each assertion. We then apply a global trustworthiness threshold to eliminate some assertions to reduce the metadatabase's overall inconsistency

The problem of collective identity in a fuzzy environment

Producción CientíficaWe define the problem of group identication in a fuzzy environment. We concentrate on the case where the society is required to self-determine the belongingness of each member to a speci_c group, characterized by a single attribute. In general terms, this case consists of a collective identity issue that can be regarded as an aggregation problem of individual assessments within a group. Here we introduce the possibility that both the original assessments and the resulting output attach partial memberships to the collectivity, for each potential member. We propose relevant classes of rules, and some are axiomatically characterized. Our new approach provides a way to circumvent classical impossibility results like Kasher and Rubinstein's.Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178

Decision Support under Risk by Optimization of Scenario Importance Weighted OWA Aggregations, Journal of Telecommunications and Information Technology, 2009, nr 3

The problem of evaluation outcomes under several scenarios to form overall objective functions is of considerable importance in decision support under uncertainty. The fuzzy operator defined as the so-called weighted OWA (WOWA) aggregation offers a well-suited approach to this problem. TheWOWA aggregation, similar to the classical ordered weighted averaging (OWA), uses the preferential weights assigned to the ordered values (i.e., to the worst value, the second worst and so on) rather than to the specific criteria. This allows one to model various preferences with respect to the risk. Simultaneously, importance weighting of scenarios can be introduced. In this paper we analyze solution procedures for optimization problems with the WOWA objective functions related to decisions under risk. Linear programming formulations are introduced for optimization of the WOWA objective representing risk averse preferences. Their computational efficiency is demonstrated

Towards a normalized trustworthiness approach to enhance security in on-line assessment

(c) 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works.This paper proposes an approach to enhance information security in on-line assessment based on a normalized trustworthiness model. Among collaborative e-Learning drawbacks which are not completely solved, we have investigated information security requirements in on-line assessment (e-assessment). To the best of our knowledge, security requirements cannot be reached with technology alone, therefore, new models such as trustworthiness approaches can complete technological solutions and support e-assessment requirements for e-Learning. Although trustworthiness models can be defined and included as a service in e-assessment security frameworks, there are multiple factors related to trustworthiness which cannot be managed without normalization. Among these factors we discuss trustworthiness multiple sources, different data source formats, measure techniques and other trustworthiness factors such as rules, evolution or context. Hence, in this paper, we justify why trustworthiness normalization is needed and a normalized trustworthiness model is proposed by reviewing existing normalization procedures for trustworthy values applied to e-assessments. Eventually, we examine the potential of our normalized trustworthiness model in a real online collaborative learning course.Peer ReviewedPostprint (author's final draft

Journal of Telecommunications and Information Technology, 2008, nr 4

kwartalni

Journal of Telecommunications and Information Technology, 2009, nr 3

kwartalni

Advances in Computational Social Science and Social Simulation

Aquesta conferència és la celebració conjunta de la "10th Artificial Economics Conference AE", la "10th Conference of the European Social Simulation Association ESSA" i la "1st Simulating the Past to Understand Human History SPUHH".Conferència organitzada pel Laboratory for Socio­-Historical Dynamics Simulation (LSDS-­UAB) de la Universitat Autònoma de Barcelona.Readers will find results of recent research on computational social science and social simulation economics, management, sociology,and history written by leading experts in the field. SOCIAL SIMULATION (former ESSA) conferences constitute annual events which serve as an international platform for the exchange of ideas and discussion of cutting edge research in the field of social simulations, both from the theoretical as well as applied perspective, and the 2014 edition benefits from the cross-fertilization of three different research communities into one single event. The volume consists of 122 articles, corresponding to most of the contributions to the conferences, in three different formats: short abstracts (presentation of work-in-progress research), posters (presentation of models and results), and full papers (presentation of social simulation research including results and discussion). The compilation is completed with indexing lists to help finding articles by title, author and thematic content. We are convinced that this book will serve interested readers as a useful compendium which presents in a nutshell the most recent advances at the frontiers of computational social sciences and social simulation researc

Cape Town Harmonies

Cape Town’s public cultures can only be fully appreciated through recognition of its deep and diverse soundscape. We have to listen to what has made and makes a city. The ear is an integral part of the ‘research tools’ one needs to get a sense of any city. We have to listen to the sounds that made and make the expansive ‘mother city’. Various of its constituent parts sound different from each other … [T]here is the sound of the singing men and their choirs (“teams” they are called) in preparation for the longstanding annual Malay choral competitions. The lyrics from the various repertoires they perform are hardly ever written down. […] There are texts of the hallowed ‘Dutch songs’ but these do not circulate easily and widely. Researchers dream of finding lyrics from decades ago, not to mention a few generations ago – back to the early 19th century. This work by Denis Constant Martin and Armelle Gaulier provides us with a very useful selection of these songs. More than that, it is a critical sociological reflection of the place of these songs and their performers in the context that have given rise to them and sustains their relevance. It is a necessary work and is a very important scholarly intervention about a rather neglected aspect of the history and present production of music in the city