http://hdl.handle.net/2117/5506 Sun, 19 May 2013 22:54:00 GMT 2013-05-19T22:54:00Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/16429 Title: Economía de la accesibilidad 20+20 : marco teórico Authors: Guasch Murillo, Daniel; Berbegal Mirabent, Jasmina; Villalta, Marta Wed, 05 Sep 2012 07:41:05 GMT http://hdl.handle.net/2117/16429 2012-09-05T07:41:05Z Guasch Murillo, Daniel; Berbegal Mirabent, Jasmina; Villalta, Marta no http://hdl.handle.net/2117/13884 Title: Hierarchical categorisation of web tags for Delicious Authors: Parra Arnau, Javier; Perego, Andrea; Ferrari, Elena; Forné Muñoz, Jorge; Rebollo Monedero, David Abstract: In the scenario of social bookmarking, a user browsing the Web bookmarks web pages and assigns free-text labels (i.e., tags) to them according to their personal preferences. The benefits of social tagging are clear – tags enhance Web content browsing and search. However, since these tags may be publicly available to any Internet user, a privacy attacker may collect this information and extract an accurate snapshot of users’ interests or user profiles, containing sensitive information, such as health-related information, political preferences, salary or religion. In order to hinder attackers in their efforts to profile users, this report focuses on the practical aspects of capturing user interests from their tagging activity. More accurately, we study how to categorise a collection of tags posted by users in one of the most popular bookmarking services, Delicious (http://delicious.com). Mon, 14 Nov 2011 18:59:20 GMT http://hdl.handle.net/2117/13884 2011-11-14T18:59:20Z Parra Arnau, Javier; Perego, Andrea; Ferrari, Elena; Forné Muñoz, Jorge; Rebollo Monedero, David no In the scenario of social bookmarking, a user browsing the Web bookmarks web pages and assigns free-text labels (i.e., tags) to them according to their personal preferences. The benefits of social tagging are clear – tags enhance Web content browsing and search. However, since these tags may be publicly available to any Internet user, a privacy attacker may collect this information and extract an accurate snapshot of users’ interests or user profiles, containing sensitive information, such as health-related information, political preferences, salary or religion. In order to hinder attackers in their efforts to profile users, this report focuses on the practical aspects of capturing user interests from their tagging activity. More accurately, we study how to categorise a collection of tags posted by users in one of the most popular bookmarking services, Delicious (http://delicious.com). http://hdl.handle.net/2117/11184 Title: Influence maximization in social Networks when negative opinions may emerge and propagate Authors: Yuan, Yifei; Wei, Wei; Chen, Wei; Collins, Alex; Cummings, Rachel; Ke, Te; Liu, Zhenming; Rincón Rivera, David; Sun, Xiaorui; Wang, Yajun Abstract: Influence maximization, defined by Kempe, Kleinberg, and Tardos (2003), is the problem of finding a small set of seed nodes in a social network that maximizes the spread of influence under certain influence cascade models. In this paper, we propose an extension to the independent cascade model that incorporates the emergence and propagation of negative opinions. The new model has an explicit parameter called quality factor to model the natural behavior of people turning negative to a product due to product defects. Our model incorporates negativity bias (negative opinions usually dominate over positive opinions) commonly acknowledged in the social psychology literature. The model maintains some nice properties such as submodularity, which allows a greedy approximation algorithm for maximizing positive influence within a ratio of 1 􀀀 1=e. We define a quality sensitivity ratio (qs-ratio) of influence graphs and show a tight bound of ( p n=k) on the qs-ratio, where n is the number of nodes in the network and k is the number of seeds selected, which indicates that seed selection is sensitive to the quality factor for general graphs. We design an efficient algorithm to compute influence in tree structures, which is nontrivial due to the negativity bias in the model. We use this algorithm as the core to build a heuristic algorithm for influence maximization for general graphs. Through simulations, we show that our heuristic algorithm has matching influence with a standard greedy approximation algorithm while being orders of magnitude faster. Tue, 25 Jan 2011 07:59:07 GMT http://hdl.handle.net/2117/11184 2011-01-25T07:59:07Z Yuan, Yifei; Wei, Wei; Chen, Wei; Collins, Alex; Cummings, Rachel; Ke, Te; Liu, Zhenming; Rincón Rivera, David; Sun, Xiaorui; Wang, Yajun no Influence maximization, Social networks, Negative opinions, Independent cascade model Influence maximization, defined by Kempe, Kleinberg, and Tardos (2003), is the problem of finding a small set of seed nodes in a social network that maximizes the spread of influence under certain influence cascade models. In this paper, we propose an extension to the independent cascade model that incorporates the emergence and propagation of negative opinions. The new model has an explicit parameter called quality factor to model the natural behavior of people turning negative to a product due to product defects. Our model incorporates negativity bias (negative opinions usually dominate over positive opinions) commonly acknowledged in the social psychology literature. The model maintains some nice properties such as submodularity, which allows a greedy approximation algorithm for maximizing positive influence within a ratio of 1 􀀀 1=e. We define a quality sensitivity ratio (qs-ratio) of influence graphs and show a tight bound of ( p n=k) on the qs-ratio, where n is the number of nodes in the network and k is the number of seeds selected, which indicates that seed selection is sensitive to the quality factor for general graphs. We design an efficient algorithm to compute influence in tree structures, which is nontrivial due to the negativity bias in the model. We use this algorithm as the core to build a heuristic algorithm for influence maximization for general graphs. Through simulations, we show that our heuristic algorithm has matching influence with a standard greedy approximation algorithm while being orders of magnitude faster. http://hdl.handle.net/2117/8121 Title: Weighted contention and interference routing metric (WCIM): Research Report Authors: Catalán Cid, Miguel; Ferrer, Josep Lluís; Gómez Montenegro, Carlos; Paradells Aspas, Josep Abstract: Contention- and Interference-Aware Flow-based Routing in Wireless Mesh Networks: design and evaluation of a novel routing metric Report 1: Analysis of WCIM model Report 2: Simulations Mon, 12 Jul 2010 09:15:07 GMT http://hdl.handle.net/2117/8121 2010-07-12T09:15:07Z Catalán Cid, Miguel; Ferrer, Josep Lluís; Gómez Montenegro, Carlos; Paradells Aspas, Josep no Contention- and Interference-Aware Flow-based Routing in Wireless Mesh Networks: design and evaluation of a novel routing metric Report 1: Analysis of WCIM model Report 2: Simulations http://hdl.handle.net/2117/6750 Title: La Internet del Futur: Anàlisi retrospectiva, reflexió i posicionament estratègic Authors: Serra Hurtado, Arturo; Alcober Segura, Jesús Ángel; Cervelló Pastor, Cristina; Domingo Pascual, Jordi; Fernández, Gabriel; Junyent Giralt, Gabriel; Oliver, Miquel; Paradells Aspas, Josep; Sallent Ribes, Sebastián Abstract: Aquest treball té com a objectiu analitzar la situació actual de la Internet, per proposar noves alternatives i dibuixar un possible camí cap a la Internet del Futur. Aquesta anàlisi vol ser un punt de partida, un document de reflexió, que posicioni als agents locals i nacionals (entorns de la recerca, innovació i producció, i usuaris) en una situació capdavantera en la construcció del nou model econòmic i social del segle XXI. El treball consta de dos grans apartats, una introducció descriptiva i conceptual del paper que juga la Internet i la seva projecció futura, i una segona part on es desdibuixen en mes profunditat les bases tecnològiques de la possible Internet del futur a partir de la realitat actual. Mon, 22 Mar 2010 13:21:16 GMT http://hdl.handle.net/2117/6750 2010-03-22T13:21:16Z Serra Hurtado, Arturo; Alcober Segura, Jesús Ángel; Cervelló Pastor, Cristina; Domingo Pascual, Jordi; Fernández, Gabriel; Junyent Giralt, Gabriel; Oliver, Miquel; Paradells Aspas, Josep; Sallent Ribes, Sebastián no Aquest treball té com a objectiu analitzar la situació actual de la Internet, per proposar noves alternatives i dibuixar un possible camí cap a la Internet del Futur. Aquesta anàlisi vol ser un punt de partida, un document de reflexió, que posicioni als agents locals i nacionals (entorns de la recerca, innovació i producció, i usuaris) en una situació capdavantera en la construcció del nou model econòmic i social del segle XXI. El treball consta de dos grans apartats, una introducció descriptiva i conceptual del paper que juga la Internet i la seva projecció futura, i una segona part on es desdibuixen en mes profunditat les bases tecnològiques de la possible Internet del futur a partir de la realitat actual. http://hdl.handle.net/2117/6491 Title: HdViPEr - High definition Videoconferencing over iP Environment Authors: Alcober Segura, Jesús Ángel; Mateu, Francesc; Pawalowski, Piotr Abstract: Notícia a l'Eurescom mess@ge 1/2009 - pàgina 7 Fri, 26 Feb 2010 16:35:56 GMT http://hdl.handle.net/2117/6491 2010-02-26T16:35:56Z Alcober Segura, Jesús Ángel; Mateu, Francesc; Pawalowski, Piotr no Notícia a l'Eurescom mess@ge 1/2009 - pàgina 7 http://hdl.handle.net/2117/2045 Title: Available Admission Capacity Estimations in IEEE 802.11 Access Points Authors: García Villegas, Eduard Abstract: This technical report is intended to provide extended information about the Available Admission Capacity estimation mechanism for IEEE 802.11 cells previously presented. The original formulation has been revised in this paper avoiding unnecessary approximations. Furthermore, a comprehensive evaluation of the algorithm is also provided. Thu, 29 May 2008 15:44:28 GMT http://hdl.handle.net/2117/2045 2008-05-29T15:44:28Z García Villegas, Eduard no Wi-Fi, 802.11, WLAN This technical report is intended to provide extended information about the Available Admission Capacity estimation mechanism for IEEE 802.11 cells previously presented. The original formulation has been revised in this paper avoiding unnecessary approximations. Furthermore, a comprehensive evaluation of the algorithm is also provided. http://hdl.handle.net/2117/2022 Title: Media Layer: redesigning the Internet as the media network of the future Authors: Miguélez Ortiz, Xavier; Iglesias Gracia, Francisco Javier; Lorente Adamuz, Pedro; Alcober Segura, Jesús Ángel; Serra Hurtado, Arturo; Sallent Ribes, Sebastián Mon, 19 May 2008 14:08:48 GMT http://hdl.handle.net/2117/2022 2008-05-19T14:08:48Z Miguélez Ortiz, Xavier; Iglesias Gracia, Francisco Javier; Lorente Adamuz, Pedro; Alcober Segura, Jesús Ángel; Serra Hurtado, Arturo; Sallent Ribes, Sebastián no Future network, Media, Network architecture, Media layer, Transport stream