Invited Talks -- Constraint Satisfaction, Complexity, and Logic -- Dynamic Discovery, Invocation and Composition of Semantic Web Services -- Information Management -- Data Brokers: Building Collections through Automated Negotiation -- P2P-DIET: Ad-hoc and Continuous Queries in Peer-to-Peer Networks Using Mobile Agents -- Taxonomy-Based Annotation of XML Documents: Application to eLearning Resources -- Precise Photo Retrieval on the Web with a Fuzzy Logic\Neural Network-Based Meta-search Engine -- Intelligent Web Prefetching Based upon User Profiles – The WebNaut Case -- An Intelligent System for Aerial Image Retrieval and Classification -- Computationally Intelligent Methods for Mining 3D Medical Images -- Text Area Identification in Web Images -- A Mixed Reality Learning Environment for Geometry Education -- A Multi-criteria Protocol for Multi-agent Negotiations -- Clustering XML Documents by Structure -- Machine Learning -- Music Performer Verification Based on Learning Ensembles -- Using the k-Nearest Problems for Adaptive Multicriteria Planning -- Focused Crawling Using Temporal Difference-Learning -- A Meta-classifier Approach for Medical Diagnosis -- Learning In-between Concept Descriptions Using Iterative Induction -- Splitting Data in Decision Trees Using the New False-Positives Criterion -- Efficient Training Algorithms for the Probabilistic RBF Network -- Using k-Nearest Neighbor and Feature Selection as an Improvement to Hierarchical Clustering -- Feature Deforming for Improved Similarity-Based Learning -- Incremental Mixture Learning for Clustering Discrete Data -- A Cost Sensitive Technique for Ordinal Classification Problems -- Pap-Smear Classification Using Efficient Second Order Neural Network Training Algorithms -- Towards an Imitation System for Learning Robots -- Data Mining and Diagnosis -- Gene Selection via Discretized Gene-Expression Profiles and Greedy Feature-Elimination -- Automatic Detection of Abnormal Tissue in Bilateral Mammograms Using Neural Networks -- Feature Selection for Robust Detection of Distributed Denial-of-Service Attacks Using Genetic Algorithms -- An Intelligent Tool for Bio-magnetic Signal Processing -- Knowledge Representation and Search -- Hierarchical Bayesian Networks: An Approach to Classification and Learning for Structured Data -- Fuzzy Automata for Fault Diagnosis: A Syntactic Analysis Approach -- A Discussion of Some Intuitions of Defeasible Reasoning -- Knowledge Representation Using a Modified Earley’s Algorithm -- Fuzzy Causal Maps in Business Modeling and Performance-Driven Process Re-engineering -- Construction and Repair: A Hybrid Approach to Search in CSPs -- Arc Consistency in Binary Encodings of Non-binary CSPs: Theoretical and Experimental Evaluation -- Inherent Choice in the Search Space of Constraint Satisfaction Problem Instances -- Natural Language Processing -- Part-of-Speech Tagging in Molecular Biology Scientific Abstracts Using Morphological and Contextual Statistical Information -- A Name-Matching Algorithm for Supporting Ontology Enrichment -- Text Normalization for the Pronunciation of Non-standard Words in an Inflected Language -- Multi-topic Information Filtering with a Single User Profile -- Exploiting Cross-Document Relations for Multi-document Evolving Summarization -- Invited Session: AI in Power System Operation and Fault Diagnosis -- Diagnosing Transformer Faults with Petri Nets -- Short-Term Load Forecasting Using Radial Basis Function Networks -- Reinforcement Learning (RL) to Optimal Reconfiguration of Radial Distribution System (RDS) -- A Multi-agent System for Microgrids -- Invited Session: Intelligent Techniques in Image Processing -- Automated Medical Image Registration Using the Simulated Annealing Algorithm -- Adaptive Rule-Based Facial Expression Recognition -- Locating Text in Historical Collection Manuscripts -- Semi-automatic Extraction of Semantics from Football Video Sequences -- Invited Session: Intelligent Virtual Environments -- Agents and Affect: Why Embodied Agents Need Affective Systems -- Synthetic Characters with Emotional States -- Control and Autonomy for Intelligent Virtual Agent Behaviour -- Reflex Movements for a Virtual Human: A Biology Inspired Approach -- Integrating miniMin-HSP Agents in a Dynamic Simulation Framework.

Arti?cial intelligence has attracted a renewed interest from distinguished sci- tists and has again raised new, more realistic this time, expectations for future advances regarding the development of theories, models and techniques and the use of them in applications pervading many areas of our daily life. The borders of human-level intelligence are still very far away and possibly unknown. Nev- theless, recent scienti?c work inspires us to work even harder in our exploration of the unknown lands of intelligence. This volume contains papers selected for presentation at the 3rd Hellenic Conference on Arti?cial Intelligence (SETN 2004), the o?cial meeting of the Hellenic Society for Arti?cial Intelligence (EETN). The ?rst meeting was held in the University of Piraeus, 1996 and the second in the Aristotle University of Thessaloniki (AUTH), 2002. SETN conferences play an important role in the dissemination of the in- vative and high-quality scienti?c results in arti?cial intelligence which are being produced mainly by Greek scientists in institutes all over the world. However, the most important e?ect of SETN conferences is that they provide the context in which people meet and get to know each other, as well as a very good opp- tunity for students to get closer to the results of innovative arti?cial intelligence research.