ramon sanguesa - Academia.edu (original) (raw)
Papers by ramon sanguesa
mechanisms evaluated for coordination in open
Conditional dependence is a way of establishing the in uence between two or more variables. In pr... more Conditional dependence is a way of establishing the in uence between two or more variables. In principle, given two variables X, and Y, X is said to be con-ditionally dependent on Y (noted I(Xj;jY) if only a subset of values of X is always associated to the selec-tion of ...
In this work we analyze the most relevant, in our opinion, algorithms for learning Bayesian Netwo... more In this work we analyze the most relevant, in our opinion, algorithms for learning Bayesian Networks. We analyze methods that use goodness-oft tests between tentative networks and data. Within this sort of learning algorithms we distinguish batch and incremental methods. Finally, we propose a system, called BANDOLER, that incrementally learns Bayesian Networks from data and prior knowledge. The incremental fashion of the system allows to modify the learning strategy and to introduce new prior knowledge during the learning process in the light of the already learnt structure.
AI Commun., 1997
Causal concepts play a crucial role in many reasoning tasks. Organised as a model revealing the c... more Causal concepts play a crucial role in many reasoning tasks. Organised as a model revealing the causal structure of a domain, they can guide inference through relevant knowledge. This is an especially difficult kind of knowledge to acquire, so some methods for automating the induction of causal models from data have been put forth. Here we review those that have a graph representation. Most work has been done on the problem of recovering belief nets from data but some extensions are appearing that claim to exhibit a true causal semantics. We will review the analogies between belief networks and “true” causal networks and to what extent methods for learning belief networks can be used in learning causal representations. Some new results in recovering possibilistic causal networks will also be presented.
CiteSeerX - Document Details (Isaac Councill, Lee Giles): Abstract: The present document explores... more CiteSeerX - Document Details (Isaac Councill, Lee Giles): Abstract: The present document explores the relationships between good practice exchange through Communities of Practice (CoPs), 2.0 technologies and their consequences for eGovernment in general and, more ...
Ponencias Y Mesas Redondas Congreso Internacional Sobre Sistemas De Informacion Historica 6 7 Y 8 De Noviembre De 1997 Vitoria Gasteiz 1998 Isbn 84 7821 358 9 Pags 261 274, 1998
Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
... Guest Editorial New perspectives on Causal Networks: the ®rst CaNew workshop (1998). Download... more ... Guest Editorial New perspectives on Causal Networks: the ®rst CaNew workshop (1998). Download: http://www-lsi.upc.es/~ia/articulos/Sanguesa-Corte CACHED: Download as a PDF. by Ramon Sanguesa , Ulises Cortes. Add To MetaCart. ...
A la memòria de mon pare que m’inculcà que els llibres són una font immensa de coneixement A la m... more A la memòria de mon pare que m’inculcà que els llibres són una font immensa de coneixement A la meva mare que em revelà que els llibres són una font de plaer infinit To the memory of my father who inculcated in me that books are an immense source of knowledge To my mother who revealed me that books are a source of infinite pleasure Agraïments i Acknowledgments The first words will be to my parents, sister and brother... Les primeres paraules d’agraiment vull que siguin per la mare i el pare per tota la dedicació que van posar en la meva educació. S’hi van haver d’escarrassar molt per a que m’interesses la lectura i per motivar-me en els estudis!!! Una forta abraçada a la meva germana i al meu germà amb qui tants jocs i baralles hem compartit. I would like to thank my advisor Ramon Sangüesa who introduced me in the field of
IEEE Systems Journal, 2009
Page 1. IEEE SYSTEMS JOURNAL, VOL. 3, NO. 1, MARCH 2009 91 A Group Selection Pattern Applied to G... more Page 1. IEEE SYSTEMS JOURNAL, VOL. 3, NO. 1, MARCH 2009 91 A Group Selection Pattern Applied to Grid Resource Management Isaac Chao, Óscar Ardáiz, and Ramón Sangüesa AbstractA key challenge in Grid computing ...
Lecture Notes in Computer Science, 2007
A key challenge in Grid computing is the achievement of efficient and self-organized management o... more A key challenge in Grid computing is the achievement of efficient and self-organized management of the Virtual Organizations composing the system. Grids are often very heterogeneous, incorporating high dynamicity and unpredictability. Introducing higher levels of adaptation and learning in the coordination protocols may help coping with complexity. We provide a solution based on a self-organized and emergent mechanism evolving congregations of policy-based resource management agents through a Group Selection process. We provide a formalization of the Group Selection pattern; we show how the mechanism fits in a Service Oriented Grid infrastructure and further evaluate by simulation its performance as an agent's policy coordination mechanism in Virtual Organizations.
Lecture Notes in Computer Science, 2007
Page 1. R. Meersman, Z. Tari, P. Herrero et al. (Eds.): OTM 2007 Ws, Part I, LNCS 4805, pp. 3739... more Page 1. R. Meersman, Z. Tari, P. Herrero et al. (Eds.): OTM 2007 Ws, Part I, LNCS 4805, pp. 3739, 2007. © Springer-Verlag Berlin Heidelberg 2007 A Group Selection Pattern Optimizing Job Scheduling in Decentralized Grid Markets Isaac Chao1, Oscar Ardaiz2, and Ramon ...
Lecture Notes in Computer Science, 2007
ABSTRACT Grids are complex systems that aggregate large amounts of distributed computational reso... more ABSTRACT Grids are complex systems that aggregate large amounts of distributed computational resources to perform large scale simulations and analysis by multiple research groups. In this paper we unveil its social networks: actors that participate in a Grid and relationships among those Grid actors. Social networking information can be used as a means to increase awareness and to facilitate collaboration among Grid participants. In practice we have implemented a social networking tool so that Grid actors can discover partners to collaborate, potential providers and consumers, and their referrals path. We present and discuss the evaluation of such tool in a user study performed with Grid resource consumers and providers.
Lecture Notes in Computer Science, 2008
Tags are arbitrary social labels carried by agents. When agents interact preferentially with thos... more Tags are arbitrary social labels carried by agents. When agents interact preferentially with those sharing the same Tag, groups are formed around similar Tags. This property can be used to achieve desired group coordination by evolving agent's Tags through a group selection process. In this paper Tags performance is for the first time compared by simulation with alternative mechanisms for coordinated learning in multiagent systems populations. We target open systems, hence we do not make costly assumption on agent capabilities (rational or computational). It is a requirement that coordination strategies prove simple to implement and scalable. We build a simulator incorporating competition and cooperation scenarios modeled as oneshot repeated games between agents. Tags prove to be a very good coordination mechanism in both cooperation building for competitive scenarios and agent behavior coordination for fully cooperative scenarios.
Lecture Notes in Computer Science, 2004
This paper proposes marketplace-based agent architecture for Grid Resource Management that works ... more This paper proposes marketplace-based agent architecture for Grid Resource Management that works on the application level. Relaying in FIPA as agent systems standard and Globus Toolkit as "de facto" middleware solution for Grid computing, we achieve the desired flexibility and modularity in order to provide a pluggable agent layer for a broader generic Grid Computing framework. The agents in the system use a utility table built previously to the system operation as information source for improving their negotiation abilities. It allows them to, given a state of the resources on the Grid, check the predicted performance of the possible configurations and select the best-rated values for some task execution parameters. We have implemented the architecture using JADE and have performed preliminary experiments consisting on multimedia processing for the conversion between video formats.
Knowledge Management and Organizational Memories, 2002
Locating expertise sources in a community of interest or practice is a critical need for distribu... more Locating expertise sources in a community of interest or practice is a critical need for distributed organizations. Usually expertise location is done through the use of personal social or knowledge networks and involves aspects such as trust and reputation. However. and especially in distributed organizations relying on communication technologies for cooperation. each member of a community is just aware of its own personal social or knowledge network. This makes difficult to get to know other potential experts in the community which may pertain to other members' networks. NetExpert is an agent-based expertise location system that replicates the process of social and knowledge network building at community or organization level. In so doing it is able to connect several networks and put into contact expertise that otherwise would remain hidden.
mechanisms evaluated for coordination in open
Conditional dependence is a way of establishing the in uence between two or more variables. In pr... more Conditional dependence is a way of establishing the in uence between two or more variables. In principle, given two variables X, and Y, X is said to be con-ditionally dependent on Y (noted I(Xj;jY) if only a subset of values of X is always associated to the selec-tion of ...
In this work we analyze the most relevant, in our opinion, algorithms for learning Bayesian Netwo... more In this work we analyze the most relevant, in our opinion, algorithms for learning Bayesian Networks. We analyze methods that use goodness-oft tests between tentative networks and data. Within this sort of learning algorithms we distinguish batch and incremental methods. Finally, we propose a system, called BANDOLER, that incrementally learns Bayesian Networks from data and prior knowledge. The incremental fashion of the system allows to modify the learning strategy and to introduce new prior knowledge during the learning process in the light of the already learnt structure.
AI Commun., 1997
Causal concepts play a crucial role in many reasoning tasks. Organised as a model revealing the c... more Causal concepts play a crucial role in many reasoning tasks. Organised as a model revealing the causal structure of a domain, they can guide inference through relevant knowledge. This is an especially difficult kind of knowledge to acquire, so some methods for automating the induction of causal models from data have been put forth. Here we review those that have a graph representation. Most work has been done on the problem of recovering belief nets from data but some extensions are appearing that claim to exhibit a true causal semantics. We will review the analogies between belief networks and “true” causal networks and to what extent methods for learning belief networks can be used in learning causal representations. Some new results in recovering possibilistic causal networks will also be presented.
CiteSeerX - Document Details (Isaac Councill, Lee Giles): Abstract: The present document explores... more CiteSeerX - Document Details (Isaac Councill, Lee Giles): Abstract: The present document explores the relationships between good practice exchange through Communities of Practice (CoPs), 2.0 technologies and their consequences for eGovernment in general and, more ...
Ponencias Y Mesas Redondas Congreso Internacional Sobre Sistemas De Informacion Historica 6 7 Y 8 De Noviembre De 1997 Vitoria Gasteiz 1998 Isbn 84 7821 358 9 Pags 261 274, 1998
Acceso de usuarios registrados. Acceso de usuarios registrados Usuario Contraseña. ...
... Guest Editorial New perspectives on Causal Networks: the ®rst CaNew workshop (1998). Download... more ... Guest Editorial New perspectives on Causal Networks: the ®rst CaNew workshop (1998). Download: http://www-lsi.upc.es/~ia/articulos/Sanguesa-Corte CACHED: Download as a PDF. by Ramon Sanguesa , Ulises Cortes. Add To MetaCart. ...
A la memòria de mon pare que m’inculcà que els llibres són una font immensa de coneixement A la m... more A la memòria de mon pare que m’inculcà que els llibres són una font immensa de coneixement A la meva mare que em revelà que els llibres són una font de plaer infinit To the memory of my father who inculcated in me that books are an immense source of knowledge To my mother who revealed me that books are a source of infinite pleasure Agraïments i Acknowledgments The first words will be to my parents, sister and brother... Les primeres paraules d’agraiment vull que siguin per la mare i el pare per tota la dedicació que van posar en la meva educació. S’hi van haver d’escarrassar molt per a que m’interesses la lectura i per motivar-me en els estudis!!! Una forta abraçada a la meva germana i al meu germà amb qui tants jocs i baralles hem compartit. I would like to thank my advisor Ramon Sangüesa who introduced me in the field of
IEEE Systems Journal, 2009
Page 1. IEEE SYSTEMS JOURNAL, VOL. 3, NO. 1, MARCH 2009 91 A Group Selection Pattern Applied to G... more Page 1. IEEE SYSTEMS JOURNAL, VOL. 3, NO. 1, MARCH 2009 91 A Group Selection Pattern Applied to Grid Resource Management Isaac Chao, Óscar Ardáiz, and Ramón Sangüesa AbstractA key challenge in Grid computing ...
Lecture Notes in Computer Science, 2007
A key challenge in Grid computing is the achievement of efficient and self-organized management o... more A key challenge in Grid computing is the achievement of efficient and self-organized management of the Virtual Organizations composing the system. Grids are often very heterogeneous, incorporating high dynamicity and unpredictability. Introducing higher levels of adaptation and learning in the coordination protocols may help coping with complexity. We provide a solution based on a self-organized and emergent mechanism evolving congregations of policy-based resource management agents through a Group Selection process. We provide a formalization of the Group Selection pattern; we show how the mechanism fits in a Service Oriented Grid infrastructure and further evaluate by simulation its performance as an agent's policy coordination mechanism in Virtual Organizations.
Lecture Notes in Computer Science, 2007
Page 1. R. Meersman, Z. Tari, P. Herrero et al. (Eds.): OTM 2007 Ws, Part I, LNCS 4805, pp. 3739... more Page 1. R. Meersman, Z. Tari, P. Herrero et al. (Eds.): OTM 2007 Ws, Part I, LNCS 4805, pp. 3739, 2007. © Springer-Verlag Berlin Heidelberg 2007 A Group Selection Pattern Optimizing Job Scheduling in Decentralized Grid Markets Isaac Chao1, Oscar Ardaiz2, and Ramon ...
Lecture Notes in Computer Science, 2007
ABSTRACT Grids are complex systems that aggregate large amounts of distributed computational reso... more ABSTRACT Grids are complex systems that aggregate large amounts of distributed computational resources to perform large scale simulations and analysis by multiple research groups. In this paper we unveil its social networks: actors that participate in a Grid and relationships among those Grid actors. Social networking information can be used as a means to increase awareness and to facilitate collaboration among Grid participants. In practice we have implemented a social networking tool so that Grid actors can discover partners to collaborate, potential providers and consumers, and their referrals path. We present and discuss the evaluation of such tool in a user study performed with Grid resource consumers and providers.
Lecture Notes in Computer Science, 2008
Tags are arbitrary social labels carried by agents. When agents interact preferentially with thos... more Tags are arbitrary social labels carried by agents. When agents interact preferentially with those sharing the same Tag, groups are formed around similar Tags. This property can be used to achieve desired group coordination by evolving agent's Tags through a group selection process. In this paper Tags performance is for the first time compared by simulation with alternative mechanisms for coordinated learning in multiagent systems populations. We target open systems, hence we do not make costly assumption on agent capabilities (rational or computational). It is a requirement that coordination strategies prove simple to implement and scalable. We build a simulator incorporating competition and cooperation scenarios modeled as oneshot repeated games between agents. Tags prove to be a very good coordination mechanism in both cooperation building for competitive scenarios and agent behavior coordination for fully cooperative scenarios.
Lecture Notes in Computer Science, 2004
This paper proposes marketplace-based agent architecture for Grid Resource Management that works ... more This paper proposes marketplace-based agent architecture for Grid Resource Management that works on the application level. Relaying in FIPA as agent systems standard and Globus Toolkit as "de facto" middleware solution for Grid computing, we achieve the desired flexibility and modularity in order to provide a pluggable agent layer for a broader generic Grid Computing framework. The agents in the system use a utility table built previously to the system operation as information source for improving their negotiation abilities. It allows them to, given a state of the resources on the Grid, check the predicted performance of the possible configurations and select the best-rated values for some task execution parameters. We have implemented the architecture using JADE and have performed preliminary experiments consisting on multimedia processing for the conversion between video formats.
Knowledge Management and Organizational Memories, 2002
Locating expertise sources in a community of interest or practice is a critical need for distribu... more Locating expertise sources in a community of interest or practice is a critical need for distributed organizations. Usually expertise location is done through the use of personal social or knowledge networks and involves aspects such as trust and reputation. However. and especially in distributed organizations relying on communication technologies for cooperation. each member of a community is just aware of its own personal social or knowledge network. This makes difficult to get to know other potential experts in the community which may pertain to other members' networks. NetExpert is an agent-based expertise location system that replicates the process of social and knowledge network building at community or organization level. In so doing it is able to connect several networks and put into contact expertise that otherwise would remain hidden.