Research Group on Knowledge & Learning Technologies (K<) 112 -K<- Introduction to Knowledge & Learning Technologies (K<) group Knowledge-based Systems (KBS) correspond to an area where there is an explicit separation between Knowledge and Inference. Expert Systems, Data Mining, Intelligent Tutors are examples of KBS. Knowledge play an important role in KBS. Nowadays, Ontologies are receiving attention, namely due to the importance of concepts and their relation for the Intelligent Agents, Semantic Web, and Knowlewdge Management. Machine Learning techniques envisage obtaining automatically, or semi-automatically, knowledge from data. Neural Networks, Decision Trees, Case-based Reasoning are just some of the used techniques. Data Mining joins AI based Machine Learning with Statistics based techniques (e.g. K-means) to allow a powerful set of tools to be used in the Knowledge Discovery effort in Information Systems. The main objective of the Knowledge & Learning Technologies group is to concentrate critical mass around these technologies in order to allow a Knowledge Society and Economy built in a correct way. We claim that “Knowledge” must not be seen just as one more keyword, and that without agents with Knowledge and Machine Learning technologies the Knowledge Society and Economy will be too limited. The main areas where this group works are: - Expert Systems - Intelligent Tutoring Systems - Ontologies - Machine Learning, Data Mining, including Neural Networks - Intelligent Agents - Semantic Web - Knowledge Management -K<- 113 Knowledge & Learning Technologies group has obtained a meaningful scientific recognition during the last years. This recognition is clear from the quality of the main publications, in scientific journals with high impact factors (e.g. the maximum is 2.202, and other 5 publications are close to 1). During the last years this group had 6 projects (SANSKI, DAMICE, ONTOMAPPER, EDGAR, Agents&Markets, EMUSSL, and TINSEL) and 3 new project will start in 2007 (IFRA, COPSRO, and COALESCE). The group covers a great variety of areas. The area of Data Mining is obtaining results at different levels, namely in terms of publications, but also in projects (DAMICE, EMUSSL and more recently COPSRO and IFRA). The area of Ontologies has obtained results in the projects (SANSKI, ONTOMAPPER, and EDGAR, and more recently in IFRA and also in COPSRO) and in good international connections. The area of Intelligent Tutoring Systems has the TINSEL project and also cooperates with the Intelligent Energy Systems group in another project (APRICOT). The area of Intelligent Agents has also importance due to the Agents&Markets project and also due to the publications. Notice that Agent-based systems are a technology covered by all groups of GECAD. Cooperation with international groups is established in several works, namely in Ontologies. Two researchers of this group, Nuno Silva and Jorge Santos, were during some months in Germany in FZI (Forschungzentrum Informatik) and AIFB (Angewandte Informatik und Formale Beschreibungsverfahren) where they contacted with some of the most prominent researchers of Ontologies (Steffen Staab, Alexander Maedche, Rudi Studer, and Rudi Studer). As a result of the stay there, two world reference platforms (MAFRA and FONTE) were developed by our researchers. These platforms are now used in 4 European R&D projects, namely, in Harmonise (IST-2000-29329), Harmo-Ten (eTEN C510828), Satine (IST-1-002104-STP), and Artemis 114 -K<- (IST-1-002103-STP). Publications with international authors have also been done in Ontologies, Intelligent Agents and Data Mining areas. -K<- 115 116 -K<- Researchers of Knowledge & Learning Technologies (K<) group Group Coordinator: Fátima Rodrigues email: [email protected] PhD Researchers Armando Silva Vieira Fernando Augusto Cruz e Silva Mouta João Manuel Simões da Rocha José António dos Reis Tavares Luiz Felipe Rocha de Faria Maria de Fátima Coutinho Rodrigues Maria João Monteiro Ferreira Viamonte Nuno Alexandre Pinto da Silva Carlos Fernando da Silva Ramos (AI&DS group) Nuno Filipe Teixeira Malheiro (IES group) Paulo Alexandre Gandra de Sousa (CI group) Non-PhD Researchers António Constantino Lopes Martins António Jorge dos Santos Pereira Fernando Jorge Ferreira Duarte Gustavo Soares Santos Hélio Artur Mendes Martins João Manuel Maia Duarte Ludimila Luiza de Lima Gabriel Luís André Andrade da Silva Oliveira Nuno Bettencourt Paulo Alexandre Fagueiro Oliveira Maio Paulo Jorge Machado Oliveira -K<- 117 118 -K<- Specific Projects of the Knowledge & Learning Technologies (K<) group SANSKI - POCTI/41830- Semi-automatic Negotiation Services for Knowledge Interoperability [2002-2005] – FCTI DAMICE – POCTI/39744 - Power Systems Consumer Profiles and Contracting Strategies supported by Data Mining [2002-2005] – FCT ONTOMAPPER - POSI/41818- Ontology Automatic Mapping [2002-2005] – FCT EDGAR - POSC/61307 - Exploiting Ontology Engineering Process Information for Semi-Automatic Knowledge Interoperability [2005-2008] – FCT Agents&Markets - POSI/56260 - Agent based Market Simulation [2005-2008] FCT TINSEL - POSI/61843 – Intelligent Tutors for Electrical Installation Design [20052008] – FCT EMUSSL - POSC/61924 - Ensemble Methods for Unsupervised and Semi-Supervised Learning [2005-2008] – FCT IFRA - PTDC/70168 - Improving Financial Risk Analysis with advanced Data-Mining tools [2007-2010] – FCT COPSRO - PTDC/EIA/69988/2006 - Computational Approach to Ontology Profiling of Scientific Research Organisations [2007-2010] – FCT COALESCE - PTDC/EIA/74417/2006 - Collaboration-based Information and Recommendation Retrieval Systems [2007-2010] – FCT -K<- 119 Budgets of Projects of Knowledge & Learning Technologies (K<) group SANSKI - € 45.000,00 DAMICE - € 32.000,00 ONTOMAPPER - € 10.000,00 EDGAR - € 75.000,00 Agents&Markets - € 74.000,00 TINSEL - € 62.500,00 EMUSSL - € 31.896,00 IFRA - € 62.000,00 COPSRO - € 146.837,00 COALESCE - € 117.984,00 iDESK (FCT Reequipment) - € 70.000,00 IPP Reequipment - € 46500,00 iDESK-RUN (FCT Basic Fund) - € 89.487,50 ISEP Basic Fund - € 5.000,00 Post-PhD hiring fund – € 220.000,00 120 -K<- SANSKI - POCTI/41830- Semi-automatic Negotiation Services for Knowledge Interoperability Project Leader: João Rocha email: jsr@ isep.ipp.pt SANSKI (Semi-automatic Negotiation Service for Knowledge Interoperability) is a project supported by FCT that started in January/2002 with the duration of 3 years. This project proposed approaches, methodologies and solutions, respecting the negotiation and translation of communication parameters, namely concerning knowledge sharing models, in order to achieve interoperability between heterogeneous entities. Several prototypes were developed in order to validate the suggested approaches. -K<- 121 DAMICE – POCTI/39744 - Power Systems Consumer Profiles and Contracting Strategies supported by Data Mining Project Leader: Fátima Rodrigues email: [email protected] DAMICE (Power Systems Consumer Profiles and Contracting Strategies supported by Data Mining) envisaged the application of Data Mining and Knowledge Discovery techniques to the existing information about electric energy consumers to obtain the characterization of different consumer profiles. The obtained knowledge is important for the suggestion of the most adequate contracts to be established. EDP cooperated with GECAD in this project. 1.2 1 0.8 0.6 0.4 0.2 0 122 Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 6 Cluster 7 Cluster 8 Cluster 9 -K<- Cluster 5 ONTOMAPPER - POSI/41818- Ontology Automatic Mapping Project Leader: João Rocha email: jsr@ isep.ipp.pt ONTOMAPPER (Ontology Automatic Mapping) is a project supported by FCT that started in March/2002 with the duration of 3 years. The correct and coherent knowledge definition, its representation, communication, share and respective methods, give rise to several problems. Also, when adopting and sharing ontologies, the elements to reason about knowledge exist, but other complementary processes are needed in order to entities agreed on the models and its meanings. In this project it was suggested to employ standard technology, like the FIPA and KQML agent communication languages (ACL), emergent standards for representing and structure information like XML/S, RDF/S and DAML+OIL. Concerning ontologies, recent tools like OILEd and OntoEdit ontology editors, Protégé as a methodology and Ontobroker and FaCT based reasoning engines were used. -K<- 123 EDGAR - POSC/61307 - Exploiting Ontology Engineering Process Information for Semi-Automatic Knowledge Interoperability Project Leader: João Rocha email: jsr@ isep.ipp.pt MAFRA Toolkit is a service-oriented tool for mapping ontologies developed by the research team of this Project. Semantic bridges have a limited support in this tool. Although all the advantages of this approach, several semantic relations are suggested for the same entities’ group. These are clearly ambiguity situations, since many services are activated due to a reduced number of imposed constraints. EDGAR project envisages providing the decreasing of the number of ambiguous resulting from the similarity measures. Research in the áreas of Ontology merging and pattern-based Ontology Engineering are being used. A formal approach, using another platform developed by this group, FONTE, is used. 124 -K<- Agents&Markets - POSI/56260 - Agent based Market Simulation Project Leader: Carlos Ramos email: [email protected] Agents&Markets (Agent-based Market Simulation) envisages the use of Multi-Agent Systems technologies in Markets Simulation. This will be an innovative proposal combining the following aspects: Agent-based Simulation; Consumer Behaviour Model; Electronic Market Analysis; Negotiation Mechanisms; Strategic Behaviours; Machine Learning and Data Mining; and other participants’ behaviour analysis with Game Theory. The basic idea of this project is to simulate markets using Intelligent Agents technology in order to be exhibited a timedependant strategic behaviour, making decisions considering the other participants behaviour (Consumer Behaviour Model, Game-Theoretic based Scenario Analysis) and providing the automation of the learning using the past interactions. The developed system will not be just a Market Simulator. It is envisaged a tool to support decision-making for one or more market participants. Two different test cases are considered: Electricity Markets and Electronic Commerce. -K<- 125 TINSEL - POSI/61843 – Intelligent Tutors for Electrical Installation Design Project Leader: Luiz Faria email: [email protected] Electrical Installations design combines academic and empirical knowledge. TINSEL project envisages the development of an Intelligent Tutoring System to support Electrical Installations designers, technical staff and Electrical Engineering students. The Project involves the development of the user model in order to support the pedagogical options of the tutoring system. A library with real cases will be used in the mapping of the main features of the cases with the domain concepts. Case-based reasoning will be used to select, adapt and store real cases, allowing to customize courses and to improve the adaptive capabilities to the trainee. Grouping and Comparison techniques will be used in the definition of the students’ stereotypes. 126 -K<- EMUSSL - POSC/61924 - Ensemble Methods for Unsupervised and Semi-Supervised Learning Project Coordinator at GECAD: Fátima Rodrigues email: [email protected] Data clustering or unsupervised learning is an important but difficult problem. The objective of clustering is to partition a set of unlabelled objects into homogeneous groups or clusters. Quantitative evaluation of the quality of clustering results is difficult due to the inherent subjectivity of the notion of cluster. Semi-supervised learning algorithms make use of both labelled and unlabelled samples and have been the focus of much recent research by the machine learning and pattern recognition communities. Semi-supervised learning has been typically viewed from a supervised learning point of view, as a being a classification problem with some missing labels. This perspective suggests the use of supervised ensemble methods to semi-supervised problems. This research direction will be exploited in the project. Additionally, one of the main threads of this project will be to address semi-supervised learning as an unsupervised learning problem with some additional knowledge/constraints. This perspective will allow semi-supervised and unsupervised problems to be addressed in an integrated fashion, which we will do with a strong emphasis on ensemble methods. This project involves IT (Telecommunications Institute) and GECAD. -K<- 127 IFRA - PTDC/70168 - Improving Financial Risk Analysis with advanced Data-Mining tools Project Coordinator at GECAD: Armando Vieira email: asv@ isep.ipp.pt Predicting when a company may declare bankruptcy is a problem of great importance for creditors - banks, bondholders and suppliers - and also for other stakeholders such as shareholders, employees, customers and State. In an increasingly globalized economy, bankruptcy results both in huge economic losses and tremendous social impact. More important than predicting the insolvency is to determine the probability to become so. This is a complex problem, normally analysed by conventional statistical techniques such as Linear Discriminant. However recent techniques, as Genetic Algorithms, Neuronal Networks, and Support Vector Machines had shown to be more robust and efficient to analyze this type of problem as well as related others. The objective of this project is to use these techniques of data classification in the field of financial risk and decision support, namely bankruptcy prediction. This project involves IST, University of Coimbra, University of Minho, and GECAD. The Bank of Portugal will cooperate in this project. 128 -K<- COPSRO - PTDC/EIA/69988/2006 - Computational Approach to Ontology Profiling of Scientific Research Organisations Project Coordinator at GECAD: Fátima Rodrigues email: [email protected] The main objective of this research work is to develop a methodology for ontology profiling scientific research organisations, including: -A reliable and valid research subject extraction method developing text mining techniques. -An effective method for establishing within-organisation similarities between the ontology items. -Adequate clustering methods for representing a research organisation by a set of possibly overlapping or fuzzy subject clusters. -Optimally mapping the subject clusters to the subject area ontology to reveal organisation’s profile. -Interpretation and evaluation of individual organisation profiles. -Combination of individual profiles into an aggregate profile. -Characterization of aggregate profiles by rule extraction. -Experimental verification of the method. The proposed methodology will be applied to scientific research organisations of computer science, specifically, Computer Science Departments of Universities in Portugal and UK, having as ontology of reference the ACM Classification System. This project involves CENTRIA and GECAD. -K<- 129 COALESCE - PTDC/EIA/74417/2006 - Collaborationbased Information and Recommendation Retrieval Systems Project Leader: Nuno Silva email: [email protected] In order to take advantage of the huge amount of data on the Web, one has to collect, filter and assemble it, relating facts and documents, as well as considering the use that each one (or community) makes of them. The project aims to research on methods and tools able to simplify and automate the management of information, through retrieval, integration and recommendation of information from multiple public and private repositories in a semantic (described through ontologies or folksonomies) and recommended fashion (according to semantic social networks emerging in the context of the Social Web. The envisaged system will be wrapped-up with a tool in the form of a Semantic Desktop, as the interface between the user and public repositories, either on the Web, PCs or mobile devices. As the Semantic Desktop and complementing technologies improves their features, the local vs. Web dichotomy tends to disappear, promoting the transparency between the physical location and type of information. 130 -K<- Main Publications in Journals of the Knowledge & Learning Technologies (K<) group • V. Matias, G. Öhl, J.C. Soares, N. P. Barradas, A. Vieira, P.P. Freitas, S. Cardoso; Determination of the composition of light thin films with artificial neural networks analysis of Rutherford backscattering experiments; Physical Review E 67, article 046705; 2003; IF=2.202. • H. Pinho, A. Vieira, N. Nené, N. Barradas; Artificial neural network analysis of multiple IBA spectra; Nuclear Instruments and Methods B; 2005; IF=1.181. • N. P. Barradas, R. N. Patrício, H. F. R. Pinho, A. Vieira; A general artificial neural network for analysis of RBS data of any element with Z between 18 and 83 implanted into any lighter one- or two-element target; Nuclear Instruments and Methods B; 219; pp. 105-109; 2003; IF=1.041. • V. Figueiredo, F. Rodrigues, Z. Vale, J. B. Gouveia; An Electric Energy Consumer Characterization Framework Based on Data Mining Techniques; IEEE Transaction on Power Systems; 20(2); pp 596-602; 2005; IF=0.951 • N. Nene, N. P. Barradas, A. Vieira; Artificial neural network analysis of RBS and ERDA spectra of multilayered multielemental samples; Nuclear Instruments and Methods B; 246(2); pp. 471-478; 2006; IF=0.946 • M. J. Viamonte, C. Ramos, F. Rodrigues, J. Cardoso; ISEM: A Multi-Agent Simulator For Testing Agent Market Strategies; IEEE -Transactions on Systems, Man and Cybernetics, Part C – Special Issue on Game-Theoric Analysis and Stochastic Simulation of Negotiation Agents; 36(1); pp. 107-113; 2006; IF=0.885. • P. Sousa; C. Ramos, J. Neves; The Fabricare Scheduling Prototype Suite: Agent interaction and knowledge base; Journal of Intelligent Manufacturing; 14(5); pp. 441-455; Kluwer Academic Publishers; 2004; IF=0.595. • A. Vieira, N. Barradas; A training algorithm for classification of high dimensional data; Neurocomputing; 50C; pp. 461-472; 2003; IF=0.592. • P. Sousa, C. Ramos, J. Neves;The Fabricare System; Production Planning & Control; 15(2); pp. 156-165; Taylor & Francis; 2004; IF=0.326. • Y. Chevaleyre, P. E. Dunne, U. Endriss, J. Lang, M. Lemaître, N. Maudet, J. Padget, S. Phelps, J.A. Rodriguez-Aguilar, P. Sousa; Issues in Multiagent -K<- 131 Resource Allocation; Informatica; 30(1); pp. 3-31; Slovenian Society Informatika; 2006; IF=0.221 • L. Faria, Z. Vale, C. Ramos, A. Marques; Diagnosis tasks intelligent training based on a model tracing approach; International Journal of Engineering Intelligent Systems; Special Issue on Knowledge Engineering; CRL Publishing; 13(4), pp. 223-230; 2005 IF=0.093 • N. Malheiro, Z. Vale, C. Ramos, M. Cordeiro, A. Gomes, A. Marques, Vieira Couto; Decision Support For Power System Control Centers – A Model Based Reasoning Component; International Journal of Engineering Intelligent Systems, Special Issue on Knowledge Engineering; CRL Publishing; 13(4); pp. 205-212; 2005; IF=0.093 • N. Silva, J. Rocha; Service oriented semi-automatic ontology mapping; International Journal of Engineering Intelligent Systems; Special Issue on Knowledge Engineering; CRL Publishing; 13(4); pp. 253-258; 2005; IF=0.093. • N. Silva, J. Rocha; Multi-dimension Service-Oriented Ontology Mapping; International Journal of Web Engineering and Technology (IJWET); 2004 • N. Silva, J. Rocha; Multidimensional service-oriented ontology mapping; International Journal of Web Engineering and Technology; Inderscience Publishers; 2(1); pp. 50-80; 2005 • J. Duarte, A. Fred, F. Rodrigues, J. Duarte, S. Ramos, Z. Vale; Weighted Evidence Accumulation Clustering using Subsampling to support the definition of Electrical Tariffs; WSEAS Transactions on Power Systems; 12(1); pp. 2001-2009; 2006 • M. J. Viamonte, C. Ramos, F. Rodrigues, J. Cardoso; ISEM: A Multi-Agent System That Simulates Competitive Electronic MarKetPlaces; Selected for publication in an upcoming special issue of the International Journal of Engineering Intelligent Systems in 2007 132 -K<- Some other Publications of the Knowledge & Learning Technologies (K<) group • J. Santos, S. Staab; Engineering a Complex Ontology with Time; Workshop of Ontologies and Distributed Systems; 18th International Joint Conference on Artificial Intelligence (IJCAI) ; Acapulco, México; 2003 • P. Oliveira, F. Rodrigues, P. Henriques; An Ontology-Based Approach For Data Cleaning; 11th International Conference on Information Quality, MIT, pp. 307-320, Boston, USA; 2006 • O. Gilson, N. Silva, P. Grant, M. Chen, J. Rocha; Online Information Visualization: Automatic Mapping of Data Entities to Representation Artefacts; Fifth International Semantic Web Conference; Athens (GA), USA; 2006 • M. J. Viamonte, C. Ramos, F. Rodrigues, J. Cardoso; A Market Simulator for Analysing Agent Market Strategies; Building the Knowledge Economy: Issues, Applications, Case Studies; IOS Press; pp. 284-291; 2003 • M. J. Viamonte, C. Ramos, J. Cardoso, F. Rodrigues; Learning User Preference Models and Business Strategies for E-Commerce; Building the Knowledge Economy; IOS Press; 2004 • M. J. Viamonte, C. Ramos, F. Rodrigues, J. Cardoso; ISEM: A Multi-Agent System for Testing the Behaviour of Electronic Market Participants; Innovation and the Knowledge Economy - Issues, Applications and Case Studies; Paul Cunningham, Miriam Cunningham (editors); IOS Press. ISBN 1574-1230; pp. 857-864; 2005 • N. Malheiro, Z. Vale, C. Ramos, V. Couto; Decision Support with Incomplete Information In Critical Situations – An Application For Power System Control Centers; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); ISBN 972-8688-39-3; 2006 • J. Duarte, A. Fred, F. Rodrigues, J. Duarte; Clustering Evidence Accumulation Clustering using the Weight of the Cluster Ensemble; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); pp. 83-90; ISBN 972-8688-39-3; 2006 • F. Rodrigues, C. Ramos, P. Henriques; A unifying Data Preparation Framework For Knowledge Discovery in Databases; Knowledge and -K<- 133 Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); pp. 59-65; ISBN 972-8688-39-3; 2006 • P. Oliveira, F. Rodrigues, P. Henriques; Data Cleaning By Reusing Domain Knowledge; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); pp. 67-74; ISBN 972-8688-39-3; 2006 • M. J. Viamonte, C. Ramos, F. Rodrigues, J. C. Cardoso; A Multi-Agent System To Support Decision Making In Competitive Electronic Marketplaces; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); pp. 189-195; ISBN 972-8688-39-3; 2006 • N. Bettencourt, P. Maio, A. Pongó, N. Silva, J. Rocha; Systematization and Clarification of Semantic Web Annotation Terminology; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.), pp. 67-74; ISBN 972-8688-39-3; 2006 • P. Maio, N. Bettencourt, N. Silva, J. Rocha; Ontology Mapping Negotiation Based on Categorization of Semantic Bridges; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.);ISBN 972-8688-39-3; 2006 • L. Faria, A. Gomes, A. Silva, Z. Vale, C. Ramos, G Santos, F. Ferreira; Intelligent Tutor for Electrical Installation Design; Knowledge and Decision Technologies; Z. Vale, C. Ramos and L. Faria (eds.); ISBN 972-8688-39-3; 2006 134 -K<- PhD and MSc Thesis of Knowledge & Learning Technologies (K<) group PhD Thesis • Nuno Silva; Multi-Dimensional Service-Oriented Ontology Mapping; PhD Thesis in Informatics; Universidade de Trás-os-Montes e Alto Douro (UTAD); 2004 • Maria João Viamonte; Mercados Electrónicos Baseados em Agentes – uma abordagem orientada ao conhecimento considerando estratégias dinâmicas (Agent-based Electronic Markets – a knowledge oriented approach considering dynamic strategies); PhD Thesis in Informatics; UTAD; 2004 • Nuno Malheiro; Processamento Inteligente de Informação em Situações Críticas – Uma Abordagem Considerando Informação Incompleta (Intelligent Information Processing in Critical Situations – an approach considering Incomplete Information); PhD Thesis in Informatics; UTAD; 2005 • Ramiro Gonçalves; Modelo Explicativo das Iniciativas de Comércio Electrónico (Initiative Explaining Model in Electronic Commerce), PhD Thesis in Informatics; UTAD; 2005 • Jorge Santos; Integração de Conhecimento Temporal em Sistemas Inteligentes (Temporal Knowledge Integration in Intelligent Systems); PhD Thesis in Informatics; UTAD; 2007 • Jorge Duarte; Clustering algorithms, validation indices and ensemble methods; PhD Thesis in Informatics; UTAD; 2007 • Paulo Oliveira; Data problems detection operations and cleaning based on dependency graphs; PhD Thesis in Informatics; University of Minho; 2007 MSc Thesis • Vera Figueiredo; Caracterização de Perfis de Consumidores de Energia Eléctrica Usando Técnicas de Data Mining (Electrical Energy Consumir Profile Characterization Using Data Mining Techniques), MSc Thesis, FEUP, 2003 • António Soares, Sistemas Automáticos de Percurso e Recolha de Informação na WEB (Automatic Systems for Information Retrieval in the WEB), MSc Thesis in Informatics, UTAD, 2004 -K<- 135 • Jorge Borges, Modelo de Data Warehouse para Análise de Serviços de Internet (Data Warehouse Model for Internet Service Analysis), MSc Thesis in Informatics, UTAD, 2004 • S. Ramos; Utilização de Técnicas de Data Mining para apoio aos Agentes dos Mercados Retalhistas de Energia Eléctrica (Data Mining Techniques for supporting Agents in Electricity Retail Markets); MSc Thesis, Instituto Superior Técnico; 2006 136 -K<-