Database and Expert Systems Applications: 18th International Conference, DEXA 2007, Regensburg, Germany, September 3-7, 2007, Proceedings (Lecture Notes in Computer Science (4653))

The annual international conference on Database and Expert Systems Applications (DEXA) is now well established as a reference scientific event. The reader will find in this volume a collection of scientific papers that represent the state of the art of - search in the domain of data, information and knowledge management, intelligent systems, and their applications. The 18th instance of the series of DEXA conferences was held at the University of Regensburg, Germany, September 3–7, 2007. Several collocated conferences and workshops covered specialized and comp- mentary topics to the main conference topic. Six conferences―the Eighth Inter- tional Conference on Data Warehousing and Knowledge Discovery (DaWaK), the Seventh International Conference on Electronic Commerce and Web Technologies (EC-Web), the Fifth International Conference on Electronic Government (EGOV), the 3rd International Conference on Trust, Privacy, and Security in Digital Business (TrustBus), the 3rd International Conference on Industrial Applications of Holonic and Multi-Agent Systems (HoloMAS), and the 1st International Conference on N- work-Based Information Systems (NBiS)―and 19 workshops were collocated with DEXA. The conference is a unique international event with a balanced depth and breadth of topics. Its much appreciated conviviality fosters unmatched opportunities to meet, share the latest scientific results and discuss the latest technological advances in the area of information technologies with young scientists and engineers as well as senior world-renown experts. Title Page Preface Table of Contents On the Efficient Processing Regular Path Expressions of an Enormous Volume of XML Data Introduction Multi-dimensional Approach to Indexing XML Data A Model An Indexing Scheme An Implementation Scheme Efficient Processing of Regular Path Expressions A Model Processing a Simple Path Query Processing a Branch Query Experimental Results Conclusion References Improving XML Instances Comparison with Preprocessing Algorithms Introduction Approaches for XML Data Similarity Definition Related Work Limitations of the Approaches Preprocessing Algorithms Lexical Preparation Terms Uniformization Hierarchy Reestructuring Complex to Simple Element Transformation Complex Elements Compatibilization Algorithms Execution Algorithms Validation Scenarios Experiments Conclusion References Storing Multidimensional XML Documents in Relational Databases Introduction Preliminaries Mutidimensional XML Storing XML Data in Relational Databases Properties of MXML Documents A Graphical Model for MXML Properties of Contexts Reduction of MXML to XML Storing MXML in Relational Databases Naive Approach Limitations of the Naive Approach A Better Approach Discussion and Motivation for Future Work References On Constructing Semantic Decision Tables Introduction Background and Motivation Semantic Decision Table The Construction Method Establish Decision Lexons Construct Semantically Grounded Decision Rules Related Work Conclusion and Future Work References Artificial Immune Recognition System Based Classifier Ensemble on the Different Feature Subsets for Detecting the Cardiac Disorders from SPECT Images Introduction SPECT Images Dataset Acquiring of SPECT Images Diagnosis of Cardiac Disorders The Proposed Method Overview FastICA Algorithm: Dimensionality Reduction Process Artificial Immune Recognition System: Classification Process The Empirical Results Results and Discussion Conclusions and Future Work References A Multisource Context-Dependent Semantic Distance Between Concepts Introduction Semantic Similarity in Text Knowledge-Based Measures Corpus-Based Measures A Context-Dependent Similarity Measure Problems with Information Content Measures A New Context-Dependency Based Measure A Corpus-Based Combination Measure Evaluation and Results The Benchmark Results Conclusion and Future Work References Self-healing Information Systems A Faceted Taxonomy of Semantic Integrity Constraints for the XML Data Model* Introduction Related Work The Proposed Taxonomy Constraint Value Constraint Range Constraint Form Constraint Check Point Constraint Action Taxonomy Application Conclusion References Beyond Lazy XML Parsing Introduction 2LP on Partitioned XML Documents Partitioning the XML File Experiments Related Work Conclusions References Efficient Processing of XML Twig Pattern: A Novel One-Phase Holistic Solution Introduction Backgrounds A One-Phase Holistic Twig Join Algorithm Notations Stack Structure Algorithm Analysis of Algorithm Experimental Results Experimental Set-Up Experimental Results Conclusion References Indexing Set-Valued Attributes with a Multi-level Extendible Hashing Scheme Introduction Related Work Preliminaries Querying Set-Valued Attributes Signature-Based Retrieval Multi-level Hashing General Description Lookups Insertions Adapting ML-Hashing to Set-Valued Queries Example Comparison of ML-Hashing with Regular Extendible Hashing Summary of Experimental Evaluation Conclusion References Adaptive Tuple Differential Coding Introduction The ATDC Algorithm Encoding Tuples Selection of Boundary Tuples Experimental Analysis ATDC vs. GZIP Compression ATDC vs. TDC Compression Conclusion References Space-Efficient Structures for Detecting Port Scans Introduction Related Work SystemModel Proposed Schemes PORT-ALERT PORT-NODE-ALERT PORT-NODE-TIME-ALERT Conclusion References A Dynamic Labeling Scheme Using Vectors Introduction Related Work Preliminaries VectorEncoding Encoding Delimiters Application of Vector Encoding Scheme Support Updating Updating in VContainment Scheme Analysis on Insertion Experiments and Evaluation Label Generation Uniform and Skewed Insertions Query Time Conclusion References A New Approach to Replication of XML Data Introduction RepliX Specifications Evaluation Related Work Conclusion References An Efficient Encoding and Labeling Scheme for Dynamic XML Data Introduction Related Works An Extended Lexicographical Order Encoding Based on Forbidden Code Segment Encoding Algorithm Code Size Analysis Application Scopes of FCS-ELO Codes Performance Study Performance Study on Static XML Performance Study on Frequent Updates Conclusion References Distributed Semantic Caching in Grid Middleware Introduction Distributed Semantic Caching Locality-Based Resolution Dual Cache Locality-Based Resolution in Dual Cache PerformanceAnalysis Testbed Configuration Experiments in a Grid RelatedWork Conclusion References Multiversion Concurrency Control for Multidimensional Index Structures Introduction Generalized Search Tree (GiST) Multiversion-GiST (MVGiST) Multiversion Concurrency Control Assumptions MVGiST Structure Supported Operations and Synchronisation Issues Read Tree Creation Strategies Evaluation Related Work Conclusion References Using an Object Reference Approach to Distributed Updates Introduction Related Research ORef Modelling Concepts and Architecture The ORef Model The ORef Architecture Object Pool Pairs Connectivity Processing Principles Materialisation Update Propagation Optimisation and Efficiency Implementation Conclusions References Towards a Novel Desktop Search Technique Introduction Challenges and Issues DataModel Issue Query Processing Issue Unified Data Model Basic Definitions Query Processing Query Optimization Optimal Filter Related Work Conclusions References An Original Usage-Based Metrics for Building a Unified View of Corporate Documents Introduction Context and Motivations Organizational Context Corporate Documents: A Quiescent Capital How to Unify Corporate Documents? An Original Usage-Based Unified Document View Modeling Documents Usage: the Multitree Data Structure Computing an Inter-Document Usage-Based Similarity Applying the Usage-Based Metrics: A Documents Unified View Conclusion and Future Works References Exploring Knowledge Management with a Social Semantic Desktop Architecture Introduction User Studies The IKOS Architecture Matching Requirements with IKOS Conclusions and Future Work References Classifying and Ranking: The First Step Towards Mining Inside Vertical Search Engines Introduction CPaper Instances Classification Instances Ranking PageRank ZRank Application Impact of Classifying Impact of Ranking Conclusion References Progressive High-Dimensional Similarity Join Introduction Related Work Non-progressive Distance Similarity Joins for High-Dimensional Data Progressive Joins and Progressive Similarity Joins Progressive Similarity Join on High-Dimensional Data Problem Definition Grid-Based Similarity Join Flushing Strategies Performance Analysis Uniform and Skewed Dataset Checkered Data Non-uniform Data Within Cells Real-Life Datasets Conclusion References Decomposing DAGs into Disjoint Chains Introduction Graph Stratification and Bipartite Graphs Stratification of DAGs Concepts of Bipartite Graphs Algorithm Description Correctness and Computational Complexities Conclusion References Evaluating Top-k Skyline Queries over Relational Databases Introduction Motivating Example Related Work Top-k Skyline Our Proposed Solutions for Top-k Skyline Experimental Study Conclusions and Future Work References A P2P Technique for Continuous k-Nearest-Neighbor Query in Road Networks Introduction Related Work Preliminaries Proposed Solution Assumptions and System Overview Server Data Structure Moving Object Data Structure Initialization Message Processing An Example Performance Study Simulation Setup Simulation Results Conclusions References Information Life Cycle, Information Value and Data Management Preface Some Basic Facts on Data and Storage Usage of Data The FileCache and FileStore Architecture FileCache Architecture for Databases Integration with Information Lifecycle Management The Quest for Eternity and Perfect Personal Memories References Vague Queries on Peer-to-Peer XML Databases Introduction Vague Queries on P2P XML Databases The VXPeer System Evaluating Vague Queries Routing VXPeer Queries Experimental Results Related Work and Conclusions References Proximity Search of XML Data Using Ontology and XPath Edit Similarity Introduction Related Work The Proposed Scheme Tag Name Expansion Using Ontologies Proximity Matching of Path Expressions Based on Edit Similarity SystemOverview Experimental Evaluation Experimental Setup Experimental Results Conclusions References Cooperative Data Management for XML Data Introduction Related Work Transaction and Cooperation Model Transaction Model Cooperation Model Transaction Protocol Operations and Lock Compatibility Tree Protocol XML Representation Conclusion References C-ARIES: A Multi-threaded Version of the ARIES Recovery Algorithm Introduction Contribution Outline ARIES C-ARIES: The Multi-threaded ARIES Algorithm Logging Fuzzy Checkpoint C-ARIES: Crash Recovery Data Structures Analysis Phase Redo Phase Undo Phase Crashes During Crash Recovery C-ARIES: Rollback During Normal Processing Sketch of Algorithms Conclusion References Optimizing Ranked Retrieval Introduction Related Work RankedQueries An Operator for Ranked Queries Equivalences for Ranked Queries Equivalences Are Not Enough Adding Soft $top~k$ Operators Operators Integration into the Query Optimizer Evaluation Comparison with Existing Approaches Larger Queries Sensitivity to Misestimations Conclusion References Similarity Search over Incomplete Symbolic Sequences Introduction Problem Description Distance Function for Complete Symbolic Sequence Distance Function for Incomplete Symbolic Sequence Proposed Approach Imputation Method Determine Positions of Missing Elements Usage in Similarity Search Extension to Real-Valued Sequence Experimental Evaluation Data Set Precision and Recall Tightness of Lower Bound and Upper Bound Conclusion References Random Multiclass Classification: Generalizing Random Forests to Random MNL and Random NB Introduction Methodology Random Forests (RF) Random MultiNomial Logit (RMNL) Random Na$\"{i}$ve Bayes (RNB) A CRM Cross-Sell Application Results Random Forests (RF) MultiNomial Logit (MNL) and Random MNL (RMNL) Naive Bayes (NB) and Random Naive Bayes (RNB) Support Vector Machines (SVM) Predictive Model Evaluation on Test Data Feature Importance Conclusion References Related Terms Clustering for Enhancing the Comprehensibility of Web Search Results Introduction Preliminaries and Definitions Query Logs and Related Terms Search Results and Document-Term Matrix Naive Clustering Methods and Their Problems The Method: Related Terms Clustering Vocabulary Selection Building the Cluster Web Application Prototype Evaluation Comparison of Clustering Quality Comparison of Clustering Comprehensibility Discussion Conclusion References Event Specification and Processing for Advanced Applications: Generalization and Formalization Introduction Background: Events and Temporal Semantics Primitive Events Composite Events Temporal Semantics Limitations Stream Data Processing Information Security Event Generalization Generalized Primitive Event Generalized Composite Event Event Registrar Graphs (ERG) Conclusions References An Evaluation of a Cluster-Based Architecture for Peer-to-Peer Information Retrieval Introduction Related Work A P2P IR Architecture Testbeds for Evaluating P2P IR Initial Evaluation Methodology and Parameters IR-Related Results Evaluating on an Optimal Testbed Characteristics and Conditions Evaluation Results Compensating for Distortion Adjusting Term-Weights on Large Testbeds Conclusions and Future Work References A Conceptual Framework for Automatic Text-Based Indexing and Retrieval in Digital Video Collections Introduction and Related Work A Strongly-Integrated Model and Its Representation Formalism The Visual Layer The Visual Semantics Facet The Signal Facet The Audio Layer Speaker Identification and Automatic Concept Detection A Conceptual Model for the Audio Layer Unification of CGs over Visual and Audio Layers Conclusion References Dimensionality Reduction in High-Dimensional Space for Multimedia Information Retrieval Introduction Related Work Lower-Bounding Function Using Cauchy-Schwartz Inequality Lower-Bounding Function Considering the Angle Component ProposedMethod Error Analysis Dimensionality Reduction Using Dimension Grouping Selection of a Reference Vector Database Construction and Query Processing Discussions Performance Evaluation Conclusions References Integrating a Stream Processing Engine and Databases for Persistent Streaming Data Management Introduction Example Scenario System Architecture Harmonica Query Language Syntax Examples Query Plan Feasibility Validation Definition Validation Algorithm Estimating Operator Costs Estimating the Maximum Writing Rate to DBMS Validation Example Experiment Related Work Conclusion References Data Management for Mobile Ajax Web 2.0 Applications Introduction Related Works Requirements to an Ajax Engine Working on Compressed XML The Solution: A DAG-Based DOM Model Server-Side Binarization of the XML Document Transferring a Binary DAG DOM Read Operations Implemented on a Binary DAG DOM Write Operations Implemented on a Binary DAG Evaluation and Results Summary and Conclusions References Data Management in RFID Applications Introduction Related Work RFID Data Modeling ER-Model and Query Types An Illustrative Example RFID Data Management Time-Line Approach Multi-table Approach Performance Study Conclusion References When Mobile Objects’ Energy Is Not So Tight: A New Perspective on Scalability Issues of Continuous Spatial Query Systems Introduction Communication System Architecture The Hybrid Wireless Network Architecture Adapting UCAN for Continuous Spatial Query Systems Models and Notations of the P2MRQ System System Assumptions Basic Notations Moving Query Model Data Structures and Algorithms of the P2MRQ System Data Structures Installing Queries Handling Query Objects that Change Their Velocity Vectors Handling Data Objects That Change Their Spatial Relationship with Nearby Queries Handling Mobile Objects That Change Their Grid Cells Performance Evaluation Simulation Study References Conclusion Sequence Alignment as a Database Technology Challenge Introduction Preliminaries Strings A Relational View on Q-Gram Indexing Profile HMM Matching Filtering The Monet Approach HMMER Experiments and Discussion Conclusions References Fuzzy Dominance Skyline Queries Introduction Skyline Operator Fuzzy Dominance Skyline Implementation Issue Performance Analysis Conclusions and Future Works References Pruning Search Space of Physical Database Design Introduction Similarity Between HP and BJIs: A Motivating Example Selecting HP and BJIs Horizontal Partitioning Selection Problem BJIs Selection Problem Pruning Search Space of BJIs Selection Using HP Greedy Algorithm for Generating BJIs Experimental Studies Conclusion References A Two-Phased Visual Query Interface for Relational Databases Introduction Basic Idea Behind OVI-2 A Working Example of OVI-2 Stage I: Specifying the Sub-concepts Stage I : Existential Quantification Stage II : Selecting the Attributes and Eliminating Unwanted Rows Implementation Issues User Comments Comparison with Other Approaches Conclusions References Wavelet Synopsis: Setting Unselected Coefficients to Zero Is Not Optimal Introduction Backgrounds and Related Work Haar Wavelet and Error Tree Wavelet-Based Data Reduction: Coefficient Thresholding Definition and Problem Formulation ($\bar{X}_{1}${\it wavelet})$^{opt}$ Construction A Counterexample Theorem and Proof Construction Algorithm of Construction Algorithm of ($\bar{X}_{1}${\it wavelet})$^{opt}$ Construction Algorithms of $\bar{X}_{k}${\it wavelet}$ Theorems and Proof Near Optimal Construction of ($\bar{X}_{k}${\it wavelet}$)^{opt}$ Experimental Evaluations Conclusions and Future Work References A Logic Framework to Support Database Refactoring Introduction Related Work Database Refactoring Through Epistemic Logic A Formalization of the Database Refactoring ProblemUsing Predicate Logic The Process of Database Refactoring Conclusions and Future Works References An Iterative Process for Adaptive Meta- and InstanceModeling Introduction Addressed Problem Areas A Concept for an Iterative Meta- and Instance Modeling Process A Concept for Iterative Meta- and Instance Modeling Within an Organizational Process MSP Meets ITIL Service Support A Platform for Iterative Meta- and Instance Modeling Related Work Further Work Conclusion References Compiling Declarative Specifications of Parsing Algorithms Introduction From Declarative Descriptions to Program Code Indexing Elements in Schemata Experimental Results Conclusions References Efficient Fragmentation of Large XML Documents Introduction SimpleX: Simple Top-Down Heuristics for Shredding an XML Document Structure Histograms Experimental Assessment Related Work Conclusions and Future Work References Locating and Ranking XML Documents Based on Content and Structure Synopses Introduction Query Specification and Document Indexing Query Processing Aggregated Ranking Extended TF*IDF Scoring Enhanced Scoring with Positional Weight Combined Scoring with Term Proximity Experimental Results Conclusion References MQTree Based Query Rewriting over Multiple XML Views Introduction Background Knowledge XPath Query XML Query Rewriting over Single XML View Problem Definition MQTree Based Query Rewriting over the Multiple XML Views The Candidate Query Rewriting Plans Generation over the MQTree The Validation of Candidate Rewriting Plan over MQTree Performance Study Experimental Setup Performance Study Related Work Conclusion References Convex Cube: Towards a Unified Structure for Multidimensional Databases Introduction and Motivations Cube Lattice Framework ConvexCubes Formalization of Existing Cubes Datacubes Others Cubes Conclusion References Dependency Management for the Preservation of Digital Information Introduction Formalizing Dependencies Intelligibility of Data Objects Intelligibility Gaps (Intelligibility-Aware) Interaction Schemes For Consuming (Delivering) Information For Providing (Ingesting) Information Complex Objects and Other Technicalities Concluding Remarks References Constraints Checking in UML Class Diagrams: SQL vs OCL Introduction Constraints Transformation Rules of Participation Constraints Checking PCs on Generalization/Specialization Associations Checking PCs on Binary Associations Recapitulative Conclusion References XML-to-SQL Query Mapping in the Presence of Multi-valued Schema Mappings and Recursive XML Schemas Introduction Related Work Motivation Preliminaries Schema-Based Query Mapping $\sigma_p$-Mapping Unfolded XML Schema Graph ID-Based Generic Query Mapping Experimental Study Conclusions and Future Work References Efficient Evaluation of Nearest Common Ancestor in XML Twig Queries Using Tree-Unaware RDBMS Introduction Framework and Contributions Relational Approaches for Twig Query Processing and Our Contributions Overview of SUCXENT++ Approach Evaluation of NCA-Twiglets DataModel and NCA-Twiglet NCA-TwigletMatching Query Translation Algorithm Performance Study Related Work Conclusions References Exclusive and Complete Clustering of Streams Introduction Our Approach Related Works ExCC Algorithm Grid Structure Speed of the Stream Grid Pruning Handling Data Drift and Outliers Clusters Generation Connectivity and Clustering Cluster Description Noise Detection Experimental Study 4.1 Performance of On-Line Component of ExCC Clustering Quality Evaluation Testing for Complete Clustering Conclusion References Clustering Quality Evaluation Based on Fuzzy FCA Introduction Backgrounds Concept Lattices Conceptual Scaling The Quality Evaluation Process Analyze Visualization Quality Evaluation Conclusion References Comparing Clustering Algorithms and Their Influence on the Evolution of Labeled Clusters Introduction Related Work $\ThemeFinder$ on an Accummulated Document Collection Experimenting with the ACM Archive Using $\ThemeFinder$ at the Clustering Results Conclusions and Outlook References Journey to the Centre of the Star: Various Ways of Finding Star Centers in Star Clustering Introduction Background and Related Works Vector and Graph Clustering Star Clustering and Extended Star Clustering Finding Star Centers Markov Stationary Distributions Lower Bound, Average and Sum Experiments Performance of Off-Line Algorithms Order of Stars Performance of Off-Line Algorithms at Different Threshold ($\sigma$) Performance of Off-Line Extended Star Algorithms Performance of On-Line Algorithms Conclusion References Improving Semantic Query Answering Introduction DL to DB Mapping Evaluation Concluding Remarks References A Method for Determining Ontology-Based Semantic Relevance Introduction Knowledge Representation on the SemanticWeb Representation of Annotations Requirements for Annotation Relevance Calculation A Method for Determining Semantic Relevance of Annotations Implementation and Evaluation Dataset Test Setting Results Conclusions of Empirical Evaluation Conclusions References Semantic Grouping of Social Networks in P2P Database Settings Introduction Interest Group Creation Group Inference Schema Merging Algorithm Performance Evaluation Related Work Summary References Benchmarking RDF Production Tools Introduction METAmorphoses Experiment Overview Compared Systems Experiment Methodology Testing Dataset Testing Environment Experiments and Results Experiments with the Result Size Experiments with the Graph Pattern Complexity Experiments with the Query Condition Complexity Discussion on Results Related Work Conclusion References Creating Learning Objects and Learning Sequence on the Basis of Semantic Networks Introduction Developing Semantic Network of the Chosen Scope of Material Creating a Distance Learning Course Marking LO Out of the Semantic Network Learning Sequence Creation Example of Using the Method Conclusion References SQORE-Based Ontology Retrieval System Introduction Related Work SQORE: Semantic Query Based Ontology Retrieval An Example: Step by Step SQORE Prototype System Experiment Experimental Design Precision vs. Recall Rank Evaluations Conclusions and Future Work References Crawling the Web with OntoDir Introduction Related Works The System Architecture The Proposed Method Word Sense Disambiguation Step Topic Detection Step Experimental Results Conclusions References Extracting Sequential Nuggets of Knowledge Introduction BasicConcepts Definitions Interestingness Measures Postfix-Projection SNK Algorithm Specification and Pseudo-code Properties of SNK Example Related Work and Discussion References Identifying Rare Classes with Sparse Training Data Introduction Related Work Seeded k-Means vs. Classification Techniques Entropy-Based Semi-supervised Learning Conclusion / Future Work References Clustering-Based K-Anonymisation Algorithms Introduction Preliminaries Clustering-Based k-Anonymisation Methods Experimental Evaluation of Clustering Strategies Conclusions References Investigation of Semantic Similarity as a Tool for Comparative Genomics Introduction The Gene Ontology Semantic Similarity The Semantic Similarity Calculator Design and Implementation Testing Conclusions and Future Work References On Estimating the Scale of National Deep Web Introduction Related Work Estimation of Russian Deep Web Scale Random Sampling of IP Addresses Stratified Random Sampling of Hosts Subject Distribution of Web Databases Discussion Conclusion References Mining the Web for Appearance Description Introduction Related Work Visual Description Mining Visualness of Adjectives Object Identification by Photographs Extracting Appearance Descriptions for General Objects from Very Large Corpus of Documents Overview Dictionary of Visual Modifiers Collection of Components/Classes Ranking of V-C Pairs Using Sampled Documents Filtering of V-C Pairs Using the Whole Documents Experiment Conclusion and Future Work References Rerank-by-Example: Efficient Browsing of Web Search Results Introduction Edit-and-Propagate Operations for Reranking Reranking Methods Selection Keyword Method Extended Keyword Method Experiment Discussion Supporting Deletion and Emphasis by Using MultiTagCloud Method of Generating MultiTagCloud Example of System Output Effectiveness of MultiTagCloud Related Work Conclusion and Future Work References Computing Geographical Serving Area Based on Search Logs and Website Categorization Introduction Related Work Definitions Serving Area Detection Computing Serving Area by Analyzing User IP Locations Computing Serving Area by Analyzing Query Terms Computing Serving Area by Web Content Classification Experiments Gazetteers and Search Logs Results for Using User IP Locations Results for Using Query Terms Results for Web Content Classification Conclusion References A General Framework to Implement Topological Relations on Composite Regions Introduction Overview of 9IM Mapping Theorem Example of Implementation Conclusion and Perspectives References Active Adjustment: An Approach for Improving the Performance of the TPR-Tree Introduction Related Work TPR-Tree TPR$\*^\-Tree The Proposed Method Motivation Basic Strategy Performance Evaluation Experimental Environment Results and Analyses Conclusions References Performance Oriented Schema Matching Introduction Related Work Preliminaries Scope Properties Our Approach Assumptions Example of Schema Integration Experimental Evaluation Conclusions References Preference-Based Integration of Relational Databases into a Description Logic Introduction Framework Syntax Semantics Enriching the Framework with Preferences over the Views Implementation Conclusion References A Context-Based Approach for the Discovery of Complex Matches Between Database Sources Introduction Informational Context Complex Concept Mining Related Work \mbox{\sc{Indigo}}'s Architecture $\Context Analyzer\ Mapper Module Experimental Results Context Mining Performance Complex Matching Evaluation Conclusion References Ontology Modularization for Knowledge Selection: Experiments and Evaluations Introduction A Case-Study for Modularization: The Knowledge Selection Scenario Modularization Techniques Ontology Partitioning Approaches Module Extraction Approaches Evaluation Criteria for Modularization Evaluating the Result of Modularization Evaluating the Modularization Tool Experiments Considered Ontologies Results for Example 1 Results for Example 2 Conclusion and Discussion: Towards a Benchmark for Modularization Techniques References The Role of Knowledge in Design Problems Introduction Design as an Ill-Structured Problem Models of Design Processes Solving Design by Problem Re-representation TheClockworkProject Conclusions References e-Infrastructures Introduction Benefits of Grid Computing for Research and Industry Grid Business and Services Case Study: The German D-Grid Initiative The D-Grid Infrastructure Project Community Grid Projects The Future: What Comes After the Grid Projects? References Author Index This book constitutes the refereed proceedings of the 18th International Conference on Database and Expert Systems Applications, DEXA 2007, held in Regensburg, Germany, September 3-7, 2007. The 86 revised full papers presented together with 1 invited paper were carefully reviewed and selected from 267 submissions. The papers are organized in topical sections on XML, data and information, datamining and data warehouses, database applications, WWW, bioinformatics, process automation and workflow, knowledge management and expert systems, database theory, query processing, as well as privacy and security