Plenary Talk -- Evolutionary Algorithms -- Rule-Based Fuzzy Inference -- Invited Session: Data Characterization through Fuzzy Clustering -- Plenary Talk -- Fuzzy Control -- Invited Session: Recent Advances in Theoretical Soft Computing -- Invited Session: Towards Intelligent Decision Support Systems via Soft Computing -- Fuzzy Logic in Decision Support -- Plenary Talk -- Applications of Fuzzy Systems -- Invited Session: Aggregation Operators -- Invited Session: Intelligent Techniques for Knowledge Extraction and Management -- Plenary Talk -- Fuzzy Image Processing -- Plenary Talk -- Invited Session: Evolutionary Algorithms -- Connectives -- Neural Networks -- Neuro-Fuzzy Systems -- Fuzzy Mathematics -- Fuzzy Optimization -- Poster Contributions.This book constitutes the refereed proceedings of the 8th Dortmund Fuzzy Days, held in Dortmund, Germany, 2004. The Fuzzy-Days conference has established itself as an international forum for the discussion of new results in the field of Computational Intelligence. All the papers had to undergo a thorough review guaranteeing a solid quality of the programme. The papers are devoted to foundational and practical issues in fuzzy systems, neural networks, evolutionary algorithms, and machine learning and thus cover the whole range of computational intelligence.