Institut für Informatik und Computational Science
Refine
Year of publication
Document Type
- Article (680)
- Doctoral Thesis (206)
- Monograph/Edited Volume (135)
- Other (28)
- Conference Proceeding (20)
- Master's Thesis (13)
- Part of a Book (12)
- Postprint (10)
- Preprint (5)
- Bachelor Thesis (1)
Keywords
- Informatik (18)
- Didaktik (15)
- Hochschuldidaktik (14)
- Ausbildung (13)
- answer set programming (13)
- Answer Set Programming (10)
- Answer set programming (10)
- E-Learning (8)
- Machine Learning (7)
- Maschinelles Lernen (7)
- Antwortmengenprogrammierung (6)
- education (6)
- Computer Science Education (5)
- Modellierung (5)
- higher education (5)
- Informatikdidaktik (4)
- Internet of Things (4)
- MQTT (4)
- Optimization (4)
- didactics (4)
- machine learning (4)
- security (4)
- Algorithms (3)
- Competence Measurement (3)
- DPLL (3)
- Digitale Medien (3)
- Digitalisierung (3)
- EEG (3)
- Equilibrium logic (3)
- Komplexität (3)
- Machine learning (3)
- Modeling (3)
- Ontologie (3)
- Secondary Education (3)
- Semantic Web (3)
- Softwareentwicklung (3)
- Theory (3)
- complexity (3)
- computer science education (3)
- formal languages (3)
- image processing (3)
- informatics (3)
- monitoring (3)
- relevance (3)
- teacher training (3)
- verification (3)
- 3D visualization (2)
- ASIC (2)
- Adaptivity (2)
- Adaptivität (2)
- Algorithmen (2)
- Analytical models (2)
- Assessment (2)
- Autismus (2)
- Automata systems (2)
- Automatisches Beweisen (2)
- Big Data (2)
- Bildungstechnologien (2)
- Bildverarbeitung (2)
- Code (2)
- Codierungstheorie (2)
- Competence Modelling (2)
- Complexity (2)
- Computational thinking (2)
- Computer Science (2)
- Computergrafik (2)
- Computersicherheit (2)
- Constraint Solving (2)
- Coq (2)
- Data Privacy (2)
- Debugging (2)
- Deduction (2)
- Deep Learning (2)
- E-learning (2)
- Educational Technologies (2)
- Event mapping (2)
- FMC (2)
- FPGA (2)
- Fault tolerance (2)
- Fehlererkennung (2)
- HCI (2)
- Hochschullehre (2)
- ICA (2)
- IT-Infrastruktur (2)
- Informatics (2)
- Informatics Education (2)
- Informatics Modelling (2)
- Informatics System Application (2)
- Informatics System Comprehension (2)
- Informatikstudium (2)
- Internet (2)
- Key Competencies (2)
- Klausellernen (2)
- Knowledge Representation and Reasoning (2)
- Konstruktivismus (2)
- Künstliche Intelligenz (2)
- Lernumgebung (2)
- Lindenmayer systems (2)
- Logic Programming (2)
- Logics (2)
- Mensch-Computer-Interaktion (2)
- Mensch-Technik-Interaktion (2)
- Methodik (2)
- Middleware (2)
- Modell (2)
- Modelling (2)
- Non-monotonic reasoning (2)
- Onlinelehre (2)
- Ontology (2)
- Optimierung (2)
- Parameterized complexity (2)
- Planing (2)
- Preference Handling (2)
- Process (2)
- Process mining (2)
- Prototyping (2)
- Prozess (2)
- Prozessmodellierung (2)
- Relevanz (2)
- ResNet (2)
- SAT (2)
- Scalability (2)
- Software Engineering (2)
- Strategie (2)
- Synthese (2)
- Systemstruktur (2)
- TPACK (2)
- Texturen (2)
- Theorembeweisen (2)
- Tracking (2)
- Treewidth (2)
- Unifikation (2)
- User Experience (2)
- Visualisierung (2)
- Vorhersage (2)
- abstraction (2)
- anti-cancer drugs (2)
- argument mining (2)
- authentication (2)
- automatic feedback (2)
- bioinformatics (2)
- code (2)
- computational thinking (2)
- computer graphics (2)
- concurrent checking (2)
- cooperating systems (2)
- deep neural networks (2)
- drug-sensitivity prediction (2)
- e-learning (2)
- edge computing (2)
- embedded systems (2)
- face tracking (2)
- facial expression (2)
- firmware update (2)
- geovisualization (2)
- human computer interaction (2)
- knowledge representation and nonmonotonic reasoning (2)
- lesson planning (2)
- lesson preparation (2)
- logic programming (2)
- maschinelles Lernen (2)
- model (2)
- non-photorealistic rendering (2)
- online learning (2)
- parsing (2)
- perception (2)
- perception differences (2)
- physical computing (2)
- policy evaluation (2)
- radhard design (2)
- reliability (2)
- scientific workflows (2)
- secondary computer science education (2)
- self-adaptive multiprocessing system (2)
- single event upset (2)
- software development (2)
- solar particle event (2)
- support system (2)
- systems biology (2)
- test (2)
- textures (2)
- theorem (2)
- tools (2)
- virtual 3D city models (2)
- virtual mobility (2)
- virtuelle 3D-Stadtmodelle (2)
- visualization (2)
- 'Peer To Peer' (1)
- (FPGA) (1)
- (SET) count rate (1)
- 13C metabolic flux analysis (1)
- 2-tag system (1)
- 21st century skills, (1)
- 3D Computer Grafik (1)
- 3D Computer Graphics (1)
- 3D Drucken (1)
- 3D Linsen (1)
- 3D Semiotik (1)
- 3D Visualisierung (1)
- 3D computer graphics (1)
- 3D lenses (1)
- 3D modeling (1)
- 3D printing (1)
- 3D semiotics (1)
- 3D-Stadtmodelle (1)
- 3d city models (1)
- 6LoWPAN (1)
- ABRACADABRA (1)
- ADFS (1)
- AODV (1)
- ARCS Modell (1)
- ASIC (Applikationsspezifische Integrierte Schaltkreise) (1)
- ASP (Answer Set Programming) (1)
- Abbrecherquote (1)
- Absorbed dose (1)
- Abstraction (1)
- Abstraktion (1)
- Accepting Grammars (1)
- Access Datenbank (1)
- Access control (1)
- Achievement (1)
- Ackerschmalwand (1)
- Active Directory Federation Services (1)
- Active Evaluation (1)
- Active evaluation (1)
- Activity Theory (1)
- Activity-orientated Learning (1)
- Ad hoc routing (1)
- Advanced Video Codec (AVC) (1)
- Adversarial Learning (1)
- Aggregates (1)
- Aktive Evaluierung (1)
- Akzeptierende Grammatiken (1)
- Algorithm configuration (1)
- Algorithm portfolios (1)
- Algorithmenablaufplanung (1)
- Algorithmenkonfiguration (1)
- Algorithmenselektion (1)
- Alignment (1)
- Android Security (1)
- Android hybrid apps (1)
- Angewandte Spieltheorie (1)
- Animal building (1)
- Anisotroper Kuwahara Filter (1)
- Anleitung (1)
- Answer Set Solving modulo Theories (1)
- Anti-cancer drugs (1)
- Antwortmengen Programmierung (1)
- App (1)
- Application Aggregation (1)
- Applications and Software Development (1)
- Applied Game Theory (1)
- Apps (1)
- Arabidopsis thaliana (1)
- Arduino (1)
- Argumentation (1)
- Argumentation structure (1)
- Artificial Intelligence (1)
- Artificial Neuronal Network (1)
- Aspect-Oriented Programming (1)
- Aspektorientierte Programmierung (1)
- Asynchrone Schaltung (1)
- Attention (1)
- Audience Response Systeme (1)
- Aufmerksamkeit (1)
- Aufzählung (1)
- Augenbewegungen (1)
- Augmentation (1)
- Augmented and virtual reality (1)
- Ausreissererkennung (1)
- Austria (1)
- Authentifizierung (1)
- Authorization (1)
- Autism (1)
- Automated Theorem Proving (1)
- Automated parallelization (1)
- Automatic Item Generation (1)
- Automatic UI Generation (1)
- Automatically controlled windows (1)
- Autorisierung (1)
- BCH (1)
- BCH code (1)
- BCH-Code (1)
- BCI (1)
- BSS (1)
- Bachelorstudierende der Informatik (1)
- Backdoors (1)
- Barcode (1)
- Batch processing (1)
- Baumweite (1)
- Bean (1)
- Behavior (1)
- Benchmark testing; (1)
- Benutzeroberfläche (1)
- Benutzungsschnittstellen Ontologien (1)
- Berliner Modell (1)
- Berührungseingaben (1)
- Betrachtungsebenen (1)
- Beweis (1)
- Beweisassistent (1)
- Beweistheorie (1)
- Beweisumgebung (1)
- Bilddatenanalyse (1)
- Bildung (1)
- Binäres Entscheidungsdiagramm (1)
- Bio-jETI (1)
- Biocomputing (1)
- Bioelektrisches Signal (1)
- Bioinformatik (1)
- Blended Learning (1)
- Blind users (1)
- Bloom’s Taxonomy (1)
- Boolean constraint solver (1)
- Boolean logic models (1)
- Boosting (1)
- Bot Detection (1)
- Brain Computer Interface (1)
- Business Process (1)
- Business Process Models (1)
- Business process intelligence (1)
- CASP (Constraint Answer Set Programming) (1)
- CP-Logic (1)
- CS concepts (1)
- CSC (1)
- Cactus (1)
- Campus (1)
- Capability approach (1)
- CertiCoq (1)
- Challenges (1)
- Chipkarten (1)
- Choreographien (1)
- Circuit faults (1)
- CityGML (1)
- Classification (1)
- Clause Learning (1)
- Clock tree (1)
- Cloud (1)
- Cloud Computing (1)
- Cloud computing (1)
- Cluster Computing (1)
- Cluster computing (1)
- Clusteranalyse (1)
- Code generation (1)
- Codierung (1)
- Coding theory (1)
- Cognitive Apprenticeship (1)
- Cognitive Skills (1)
- Coherent phonons (1)
- Combinatorial multi-objective optimization (1)
- Common Spatial Pattern (1)
- Competences (1)
- Competencies (1)
- Complementary Circuits (1)
- Complex optimization (1)
- Compliance (1)
- Composed UIs (1)
- Composition (1)
- Computational Complexity (1)
- Computational Science (1)
- Computational Thinking (1)
- Computational complexity (1)
- Computational grid (1)
- Computer Science in Context (1)
- Computer security (1)
- Computergestützes Training (1)
- Computing (1)
- Computing with DNA (1)
- Conceptual (1)
- Conformant Planning (1)
- Conrad Hal Waddington (1)
- Constraint (1)
- Constraint satisfaction (1)
- Constraint-Programmierung (1)
- Constructive solid geometry (1)
- Contest (1)
- Context awareness (1)
- Contextualisation (1)
- Contextualized learning (1)
- Continuous Testing (1)
- Continuous Versioning (1)
- Contradictions (1)
- Controlled Derivations (1)
- Convolution (1)
- Course timetabling (1)
- Covariate Shift (1)
- Curriculum (1)
- Curriculum Development (1)
- Curry (1)
- Customer ownership (1)
- D-galactosamine (1)
- DDoS (1)
- DMR (1)
- DNA (1)
- DNA computing (1)
- DNA hairpin formation (1)
- DNS (1)
- DRMAA (1)
- DRMS (1)
- Data Analysis (1)
- Data Management (1)
- Data federation (1)
- Database (1)
- Databases (1)
- Dateiformat (1)
- Datenschutz (1)
- Deal of the Day (1)
- Decidability (1)
- Declarative Problem Solving (1)
- Declare (1)
- Deep learning (1)
- Defining characteristics of physical computing (1)
- Dempster-Shafer-Theorie (1)
- Dempster–Shafer theory (1)
- Denotational semantics (1)
- Description Logics (1)
- Design (1)
- Design for testability (DFT) (1)
- Deskriptive Logik (1)
- Deutschland (1)
- Diagonalisierung (1)
- Dialog-based User Interfaces (1)
- Dialogbasierte Benutzerschnittstellen (1)
- Didaktik der Informatik (1)
- Didaktische Konzepte (1)
- Dienst-Ökosysteme (1)
- Dienstkomposition (1)
- Dienstplattform (1)
- Differenz von Gauss Filtern (1)
- Digital Competence (1)
- Digital Design (1)
- Digital Education (1)
- Digital Game Based Learning (1)
- Digital Media (1)
- Digital Revolution (1)
- Digital image analysis (1)
- Digitale Bibliothek (1)
- Digitalisation (1)
- Digitalization (1)
- Distributed Computing (1)
- Diversität (1)
- Dokument-Management-System (1)
- Domain-Specific Languages (1)
- Domänenspezifische Sprachen (1)
- Dose rate (1)
- Double cell upsets (DCUs) (1)
- Dreidimensionale Computergraphik (1)
- Dublin Core (1)
- Dynamic Programming (1)
- Dynamic assessment (1)
- Dynamical X-ray theory (1)
- Dynamische Programmierung (1)
- Dynamische Rekonfiguration (1)
- E-Assessment (1)
- E-Government (1)
- E-Klausuren (1)
- E-Portfolio (1)
- E-teaching (1)
- EDC (1)
- Early Literacy (1)
- Echtzeitanwendung (1)
- Edge Computing (1)
- Educational Standards (1)
- Educational game (1)
- Educational software (1)
- Educational timetabling (1)
- Eingabegenauigkeit (1)
- Eisenbahnnetz (1)
- Elektroencephalographie (1)
- Elektronisches Prüfen (1)
- Elektronisches Publizieren (1)
- Embedded Systems (1)
- Emotionen (1)
- Emotionsforschung (1)
- Encoding (1)
- Engines (1)
- Enterprise Architecture (1)
- Enterprise Search (1)
- Entity Linking (1)
- Entscheidungsbäume (1)
- Entwurf (1)
- Entwurfsmuster (1)
- Entwurfsmuster für SOA-Sicherheit (1)
- Entwurfsprinzipien (1)
- Entwurfsraumexploration (1)
- Epigenetic landscape (1)
- Epistemic Logic Programs (1)
- Erfüllbarkeit einer Formel der Aussagenlogik (1)
- Erfüllbarkeitsproblem (1)
- Erklärbarkeit (1)
- Error Estimation (1)
- Error-Detection Circuits (1)
- Euclid’s algorithm (1)
- European Bioinformatics Institute (1)
- Evaluation (1)
- Evaluierung semantischer Suchmaschinen (1)
- Evidenztheorie (1)
- Evolution (1)
- Experimentation (1)
- Explainability (1)
- Explicit negation (1)
- Exploration (1)
- Explore-first Programming (1)
- Exponential Time Hypothesis (1)
- Exponentialzeit Hypothese (1)
- Extensibility (1)
- Extreme Model-Driven Development (1)
- FEDC (1)
- FMC-QE (1)
- FOSS (1)
- Facebook (1)
- Fault Localization (1)
- Fault tolerant systems (1)
- Feature Combination (1)
- Feature extraction (1)
- Feedback (1)
- Fehlende Daten (1)
- Fehlerkorrektur (1)
- Fehlerschätzung (1)
- Fehlvorstellung (1)
- Fibonacci numbers (1)
- Field programmable gate arrays (1)
- Finite automata (1)
- Flip-flops (1)
- Flussgesteuerter Bilateraler Filter (1)
- Focus+Context Visualization (1)
- Fokus-&-Kontext Visualisierung (1)
- Forgetting (1)
- Formalismus (1)
- Formalitätsgrad (1)
- Formeln der quantifizierten Aussagenlogik (1)
- Forschendes Lernen (1)
- Forschungsdatenmanagement (1)
- Framework (1)
- Freshmen (1)
- Function (1)
- Fundamental Ideas (1)
- GERBIL (1)
- GIS-Dienstkomposition (1)
- GPU (1)
- Game-Design-Elemente (1)
- Game-based learning (1)
- Gamification (1)
- Gebrauchstauglichkeit (1)
- Gebäudemodelle (1)
- Gehirn-Computer-Schnittstelle (1)
- Geländemodelle (1)
- Generalisierung (1)
- Generative Programmierung (1)
- Generative Programming (1)
- Geodaten (1)
- Geometrieerzeugung (1)
- Geovisualisierung (1)
- Geräte-Treiber (1)
- Geschäftsprozess (1)
- Geschäftsprozessmodelle (1)
- Gesichtsausdruck (1)
- Gesteuerte Ableitungen (1)
- Gesture input (1)
- Gleichheit (1)
- Globus (1)
- Grammar Systems (1)
- Grammatikalische Inferenz (1)
- Grammatiksysteme (1)
- Graph Convolutional Neural Networks (1)
- Graph Embedding (1)
- Graph-basiertes Ranking (1)
- Graphensuche (1)
- Graphfärbung (1)
- Green computing (1)
- Grid (1)
- Grid Computing (1)
- Grounded theory (1)
- Grounding Theory (1)
- H.264 (1)
- HDI (1)
- Hairpin completions (1)
- Hairpin reductions (1)
- Hardware Design (1)
- Hardware accelerator (1)
- Hardware-Software-Co-Design (1)
- Hauptkomponentenanalyse (1)
- Heat diffusion (1)
- Heterogenität (1)
- Hierarchically configurable mask register (1)
- High-Level Synthesis (1)
- Histograms (1)
- Hochschul-Apps (1)
- Hochschul-Cloud (1)
- Hochschulbildung (1)
- Hochschulsystem (1)
- Https traffic (1)
- Human Factors (1)
- Human-Technology Interaction (1)
- Hurricane Sandy (1)
- Hybrid App (1)
- I/O-effiziente Algorithmen (1)
- ICT (1)
- ICT Competence (1)
- ICT competencies (1)
- ICT skills (1)
- IP core (1)
- IT security (1)
- IT-Security (1)
- IT-Sicherheit (1)
- IaaS (1)
- Identifiers (1)
- Image and video stylization (1)
- Image resolution (1)
- Imperative calculi (1)
- Improving classroom (1)
- Incoherent phonons (1)
- Incremental answer set programming (1)
- Industrie 4.0 (1)
- Industry 4.0 (1)
- Inference (1)
- Informatik-Studiengänge (1)
- Informatiksystem (1)
- Informatikunterricht (1)
- Informatikvoraussetzungen (1)
- Information Retrieval (1)
- Information Transfer Rate (1)
- Information federation (1)
- Information integration (1)
- Information retrieval (1)
- Information security (1)
- Informationsextraktion (1)
- Infrastruktur (1)
- Inkonsistenz (1)
- Innovation (1)
- Inquiry-based Learning (1)
- Inquiry-based learning (1)
- Insurance industry (1)
- Integrated circuit modeling (1)
- Integration (1)
- Interactive Rendering (1)
- Interactive system (1)
- Interaktionsmodel (1)
- Interaktionsmodellierung (1)
- Interaktionstechniken (1)
- Interaktives Rendering (1)
- Interaktives System (1)
- Interaktivität (1)
- Interface design (1)
- Internet Security (1)
- Internet applications (1)
- Internet-Sicherheit (1)
- Internetanwendungen (1)
- Interoperability (1)
- Interoperabilität (1)
- Interpretability (1)
- Interpretierbarkeit (1)
- Intuition (1)
- IoT (1)
- Java Security Framework (1)
- Job monitoring (1)
- Job submission (1)
- Kartografisches Design (1)
- Kern-PCA (1)
- Kernel (1)
- Kernelization (1)
- Kernmethoden (1)
- Key input (1)
- Klassifikation (1)
- Klassifikation mit großem Margin (1)
- Klassifikator-Kalibrierung (1)
- Klimafolgenanalyse (1)
- Klimawandel (1)
- Knowledge (1)
- Knowledge Management (1)
- Knowledge representation (1)
- Kommunikation (1)
- Kommunismus (1)
- Kompetenz (1)
- Kompetenzerwerb (1)
- Kompilation (1)
- Komplexitätsbewältigung (1)
- Komplexitätstheorie (1)
- Komposition (1)
- Konnektionskalkül (1)
- Konzeptionell (1)
- Kryptographie (1)
- Kybernetik (1)
- Künstliche Neuronale Netzwerke (1)
- L systems (1)
- LBA problem (1)
- LDPC code (1)
- LDPC-Code (1)
- LMS (1)
- Landmark visibility (1)
- Landmarken (1)
- Langzeitarchivierung (1)
- Large Margin Classification (1)
- Laser Cutten (1)
- Learners (1)
- Learning (1)
- Learning Analytics (1)
- Learning Fields (1)
- Learning ecology (1)
- Learning environment (1)
- Learning interfaces development (1)
- Learning with ICT (1)
- Lebenslanges Lernen (1)
- Leftmost Derivations (1)
- Lehre (1)
- Lehrer (1)
- Lehrer*innenbildung (1)
- Lehrkräfteausbildung (1)
- Leistungsfähigkeit (1)
- Leistungsvorhersage (1)
- Lern-App (1)
- Lernaufgaben (1)
- Lernen (1)
- Lernmotivation (1)
- Lernsoftware (1)
- Life-Long Learning (1)
- Liguistisch (1)
- Linked Data Anwendungen (1)
- Linked Data Application Modelling (1)
- Linksableitungen (1)
- Linux (1)
- Linux device drivers (1)
- Literature mining (1)
- Liver neoplasms (1)
- Load Balancing (1)
- Localization (1)
- Location awareness (1)
- Logarithm (1)
- Logic programming (1)
- Logik (1)
- Logikkalkül (1)
- Logiksynthese (1)
- Loss (1)
- Low Latency (1)
- Lower Bounds (1)
- Lower Secondary Level (1)
- Loyalty (1)
- M2M (1)
- MEG (1)
- MFA (1)
- MOOCs (1)
- Magnetoencephalographie (1)
- Malware (1)
- Markov processes (1)
- Masking of X-values (1)
- Massenklausuren (1)
- Massive Open Online Courses (1)
- Mathematical Optimization (1)
- Mathematikdidaktik (1)
- Mathematikphilosophie (1)
- Mathematische Optimierung (1)
- Matrizen-Eigenwertaufgabe (1)
- Measurement (1)
- Media in education (1)
- Megamodel (1)
- Megamodell (1)
- Mehrklassen-Klassifikation (1)
- Message Passing Interface (1)
- Meta-Programming (1)
- Metamodell (1)
- Methoden der semantischen Suche (1)
- Methodology (1)
- Metric learning (1)
- Migration (1)
- Minimal perturbation problems (1)
- Mischmodelle (1)
- Mischung <Signalverarbeitung> (1)
- Mobile App (1)
- Mobile Campus Application (1)
- Mobile Learning (1)
- Mobile application (1)
- Mobile devices (1)
- Mobile learning (1)
- Mobiles Lernen (1)
- Mobilgeräte (1)
- Model Based Engineering (1)
- Model Checking (1)
- Model Driven Architecture (1)
- Model Driven UI Development (1)
- Model Management (1)
- Model checking (1)
- Model-Driven Engineering (1)
- Model-Driven Software Development (1)
- Modell Management (1)
- Modell-driven Security (1)
- Modell-getriebene Sicherheit (1)
- Modellbasiert (1)
- Modellgetriebene Architektur (1)
- Modellgetriebene Entwicklung (1)
- Modellgetriebene Softwareentwicklung (1)
- Modellgetriebene UI Entwicklung (1)
- Molekulare Bioinformatik (1)
- Motivation (1)
- Multi Task Learning (1)
- Multi-Class (1)
- Multi-Task-Lernen (1)
- Multi-objective optimization (1)
- Multi-sided platforms (1)
- Multimedia (1)
- Multimodal User Interfaces (1)
- Multimodale Benutzerschnittstellen (1)
- Multiple interpretation scheme (1)
- Multiprocessor (1)
- Multiprozessor (1)
- Music Technology (1)
- N-temperature model (1)
- NETCONF (1)
- NFC (1)
- NUI (1)
- Nash equilibrium (1)
- Natural Science Education (1)
- Natural language processing (1)
- Natural ventilation (1)
- Navigation (1)
- Network (1)
- Network Management (1)
- Network security (1)
- Netzwerk (1)
- Netzwerk Management (1)
- Netzwerke (1)
- Neural networks (1)
- Neuronales Netz (1)
- New On-Line Error-Detection Methode (1)
- Next Generation Network (1)
- Nicht-photorealistisches Rendering (1)
- Nichtfotorealistische Bildsynthese (1)
- NoSQL (1)
- Non-Monotonic (1)
- Nonmonotonic reasoning (1)
- Norway (1)
- Novice programmers (1)
- Nutzungserlebnis (1)
- Nutzungsinteresse (1)
- OAI-PMH (1)
- OBI (1)
- OCCI (1)
- OSSE (1)
- Objektive Schwierigkeit (1)
- Omega (1)
- Ontologien (1)
- Ontologies (1)
- Open Badge Infrastructure (1)
- Open Badges (1)
- Open Source (1)
- OpenOLAT (1)
- Operation problem (1)
- Optimierungsproblem (1)
- Owner-Retained Access Control (ORAC) (1)
- Parallel Programming (1)
- Parallel SAT solving (1)
- Parallel job execution time estimation (1)
- Parallele Datenverarbeitung (1)
- Paralleles Rechnen (1)
- Parallelrechner (1)
- Parameterized Complexity (1)
- Parametrisierte Komplexität (1)
- Parsing (1)
- Particle detector (1)
- Partizipation (1)
- Patterns (1)
- Pedagogical content knowledge (1)
- Pedagogical issues (1)
- Pedestrian navigation (1)
- Peer-Review (1)
- Peer-to-Peer-Netz ; GRID computing ; Zuverlässigkeit ; Web Services ; Betriebsmittelverwaltung ; Migration (1)
- Performance (1)
- Performance Evaluation (1)
- Performance Prediction (1)
- Perl Formularskript (1)
- Personal Learning Environment (1)
- Personalization (1)
- Persönliche Lernumgebung (1)
- Pervasive computing (1)
- Pervasive game (1)
- Pervasive learning (1)
- Phantoms (1)
- Physical Science (1)
- Planar tactile display (1)
- Plant identification (1)
- Platzierung (1)
- Polarization (1)
- Policy Enforcement (1)
- Policy Languages (1)
- Policy Sprachen (1)
- Power Monitoring (1)
- Pre-RS Traceability (1)
- Prediction Game (1)
- Predictive Models (1)
- Preprocessing (1)
- Privacy Protection (1)
- Problem Solving (1)
- Probleme in der Studie (1)
- Problemlösen (1)
- Process Management (1)
- Process model analysis (1)
- Process modeling (1)
- Product lifecycle management (1)
- Professionalisierung (1)
- Professoren (1)
- Programmierung (1)
- Programming (1)
- Programming by optimization (1)
- Proof Theory (1)
- Prototyp (1)
- Prozess Verbesserung (1)
- Prozesse (1)
- Prozessmanagement (1)
- Prozessmodell (1)
- Prozesssynchronisierung (1)
- Prädiktionsspiel (1)
- Präferenzen (1)
- Prüfungsoptimierung (1)
- Publikationsserver (1)
- Quantenkryptographie (1)
- Quantified Boolean Formula (QBF) (1)
- Quantitative Modeling (1)
- Quantitative Modellierung (1)
- Queuing Theory (1)
- RADFET (1)
- RADFETs (1)
- REST (1)
- RSA triangle (1)
- Radiation hardness (1)
- Random access memory (1)
- Ranking (1)
- Reasoning (1)
- Recommendations for CS-Curricula in Higher Education (1)
- Reconfigurable (1)
- Reflexion (1)
- Region of Interest (1)
- Regression (1)
- Regularisierung (1)
- Regularization (1)
- Rekonfiguration (1)
- Rendering (1)
- Reparatur (1)
- Reproducibility of results (1)
- Reuseable UIs (1)
- Reversibility (1)
- SAMR (1)
- SET pulsewidth distribution (1)
- SMT (SAT Modulo Theories) (1)
- SOA (1)
- SOA Security Pattern (1)
- SSO (1)
- STG decomposition (1)
- STG-Dekomposition (1)
- SWOT (1)
- SaaSAbstract (1)
- Sample Selection Bias (1)
- Satisfiability (1)
- Scale-invariant feature transform (SIFT) (1)
- Scene graph systems (1)
- Schlüsselkompetenzen (1)
- Schulmaterial (1)
- Scientific images (1)
- Screen reader (1)
- Seamless learning (1)
- Search problems (1)
- Security (1)
- Security Modelling (1)
- Segmentierung (1)
- Selektion (1)
- Selektionsbias (1)
- Self-Checking Circuits (1)
- Self-adaptive MPSoC (1)
- Semantic Interoperability (1)
- Semantic Search (1)
- Semantic data (1)
- Semantic web (1)
- Semantik Web (1)
- Semantische Suche (1)
- Semilinearity property (1)
- Sensornetzwerke (1)
- Sensors (1)
- Sequence embeddings (1)
- Service Creation (1)
- Service Delivery Platform (1)
- Service Ecosystems (1)
- Service Oriented Architectures (1)
- Service convergence (1)
- Service orientation (1)
- Service-Orientierte Architekturen (1)
- Service-oriented Architecture (1)
- Service-oriented Architectures (1)
- Service-oriented architecture (1)
- Serviceorientierte Architektur (1)
- Shader (1)
- Sharing (1)
- Sicherheitsmodellierung (1)
- Signal Processing (1)
- Signal processing (1)
- Signaling transduction networks (1)
- Signalquellentrennung (1)
- Signaltrennung (1)
- Simulation (1)
- Simulations (1)
- Simultane Diagonalisierung (1)
- Single Event Transient (1)
- Single Sign On (1)
- Single Trial Analysis (1)
- Single event effect (1)
- Single event upsets (1)
- Single-event transient (SET) (1)
- Skalierbarkeit (1)
- Skelettberechnung (1)
- Small Private Online Courses (1)
- Social (1)
- Social Media Analysis (1)
- Software (1)
- Software architecture (1)
- Software-basierte Cache-Kohärenz (1)
- Softwarearchitektur (1)
- Sonnenteilchen-Ereignis (1)
- Spam (1)
- Spam Filtering (1)
- Spam-Erkennung (1)
- Spam-Filter (1)
- Spam-Filtering (1)
- Spatio-Spectral Filter (1)
- Spawning (1)
- Speicher (1)
- Spielbasiertes Lernen (1)
- Splicing (1)
- Splicing processor (1)
- Sprachdesign (1)
- Static Analysis (1)
- Statistical Tests (1)
- Statistical relational learning (1)
- Statistikprogramm R (1)
- Statistische Tests (1)
- Stilisierung (1)
- Stochastic relational process (1)
- Strahlungshartes Design (1)
- Strahlungshärte Entwurf (1)
- Stromverbrauchüberwachung (1)
- Strong equivalence (1)
- Structural equation modeling (1)
- Structuring (1)
- Strukturierung (1)
- Studentenerwartungen (1)
- Studentenhaltungen (1)
- Studentenjobs (1)
- Studienabbrecher (1)
- Studiendauer (1)
- Studieneinstieg (1)
- Studienorganisation (1)
- Suche (1)
- Support Vectors (1)
- Support-Vector Lernen (1)
- System Biologie (1)
- System structure (1)
- Systembiologie (1)
- Systementwurf (1)
- Systems biology (1)
- Systems of parallel communicating (1)
- Szenengraph (1)
- TMR (1)
- TPTP (1)
- Tailored UI Variants (1)
- Taktik (1)
- Tasks (1)
- Teacher perceptions (1)
- Teachers (1)
- Teaching information security (1)
- Technology proficiency (1)
- Teilnehmerzertifikate (1)
- Telekommunikation (1)
- Temporal Answer Set Solving (1)
- Temporal Logic (1)
- Temporallogik (1)
- Temporäre Anbindung (1)
- Terminologische Logik (1)
- Terminology (1)
- Test (1)
- Tests (1)
- Theoretische Informatik (1)
- Theoretischen Vorlesungen (1)
- Theory formation (1)
- Thermoelasticity (1)
- Time Augmented Petri Nets (1)
- Time Series Analysis (1)
- Time series (1)
- Tomography (1)
- Tool (1)
- Tools (1)
- Traceability (1)
- Traffic data (1)
- Transformation (1)
- Tree decomposition (1)
- Treewidth-aware reductions (1)
- Triple modular redundancy (TMR) (1)
- Tumor types (1)
- Turing machine (1)
- Type and effect systems (1)
- UAV imagery (1)
- UI Components (1)
- UI Metamodels (1)
- UI-Komponenten (1)
- UX (1)
- Ubiquitous learning (1)
- Ultrafast dynamics (1)
- Unabhängige Komponentenanalyse (1)
- Unary languages (1)
- Uniform Access Principle (1)
- University Service Bus (1)
- Universität Bagdad (1)
- Universität Potsdam (1)
- Universitätseinstellungen (1)
- Untere Schranken (1)
- Unterrichtswerkzeuge (1)
- Unvollständigkeit (1)
- Usability (1)
- Usability testing (1)
- Usage Interest (1)
- User Interface Ontologies (1)
- User Interfaces (1)
- User submission pattern (1)
- User-centred design (1)
- VGG16 (1)
- VM (1)
- Value network (1)
- Verhalten (1)
- Verification (1)
- Verifikation (1)
- Verletzung Auflösung (1)
- Verletzung Erklärung (1)
- Verteiltes Rechnen (1)
- Verteilungsunterschied (1)
- Violation Explanation (1)
- Violation Resolution (1)
- Virtual Reality (1)
- Virtual reality (1)
- Virtuelles 3D Stadtmodell (1)
- Visual metaphor (1)
- Vocational Education (1)
- Vorhersagemodelle (1)
- Wahrnehmung (1)
- Wahrnehmung von Arousal (1)
- Wahrnehmungsunterschiede (1)
- Warteschlangentheorie (1)
- Web Services (1)
- Web Sites (1)
- Web of Data (1)
- Webanwendung (1)
- Webseite (1)
- Weiterbildung (1)
- Well-structuredness (1)
- Wetterextreme (1)
- Wireless Sensor Networks (1)
- Wirtschaftsinformatik (1)
- Wissen (1)
- Wissenschaftlichesworkflows (1)
- Wissensmanagement (1)
- Wissensrepräsentation und -verarbeitung (1)
- Wissensrepräsentation und Schlussfolgerung (1)
- Wohlstrukturiertheit (1)
- Word embeddings (1)
- Workflow (1)
- X-masking (1)
- X-ray computed (1)
- X-values (1)
- Young People (1)
- ZQSA (1)
- ZQSAT (1)
- Zeitbehaftete Petri Netze (1)
- Zero-Suppressed Binary Decision Diagram (ZDD) (1)
- Zuverlässigkeitsanalyse (1)
- accepting grammars (1)
- action and change (1)
- activities (1)
- activity (1)
- acute liver failure (1)
- acyclicity properties (1)
- adaptiv (1)
- adaptive (1)
- adversarial classification (1)
- algorithm configuration (1)
- algorithm schedules (1)
- algorithm scheduling (1)
- algorithm selection (1)
- algorithms (1)
- analogical thinking (1)
- analysis (1)
- animated PCA (1)
- animierte PCA (1)
- anisotropic Kuwahara filter (1)
- annealing (1)
- anxiety (1)
- approximate joint diagonalization (1)
- approximate model counting (1)
- architecture (1)
- argumentation (1)
- argumentation structure (1)
- arithmethische Prozeduren (1)
- arithmetic procedures (1)
- arousal (1)
- arousal perception (1)
- artificial intelligence (1)
- artistic rendering (1)
- assistive Technologien (1)
- assistive technologies (1)
- asynchronous circuit (1)
- asynchrounous design (1)
- autism (1)
- automata (1)
- automated driving (1)
- automated guided vehicle routing (1)
- automated planning (1)
- automated theorem proving (1)
- automatic theorem prover (1)
- automatisierter Theorembeweiser (1)
- behavioral (1)
- behavioral abstraction (1)
- belief merging (1)
- belief revision (1)
- benchmark (1)
- bibliometric analysis (1)
- bild (1)
- binary representation (1)
- binary search (1)
- bio-computing (1)
- biometrics (1)
- biometrische Identifikation (1)
- blind source separation (1)
- block representation (1)
- bootstrapping (1)
- brain-computer interface (1)
- building models (1)
- bundled data (1)
- business informatics (1)
- camera sensor (1)
- car assembly operations (1)
- cartographic design (1)
- cellular automata (1)
- changing the study field (1)
- changing the university (1)
- choreographies (1)
- circuit Faults (1)
- citation analysis (1)
- classifier calibration (1)
- classroom language (1)
- classroom material (1)
- clause learning (1)
- click controller (1)
- climate change (1)
- climate impact analysis (1)
- clocks (1)
- clustering (1)
- co-citation analysis (1)
- co-occurrence analysis (1)
- code generation (1)
- cognitive apprenticeship (1)
- cognitive modifiability (1)
- coherence relation (1)
- coherence-enhancing filtering (1)
- collaborative learning (1)
- combinatorial optimization problems (1)
- combined task and motion planning (1)
- common spatial patterns (1)
- communication (1)
- competence (1)
- competencies (1)
- competency (1)
- competition (1)
- compilation (1)
- complex networks (1)
- compliance (1)
- comprehension (1)
- computational biology (1)
- computational methods (1)
- computer science teachers (1)
- computer security (1)
- computer vision (1)
- computergestützte Methoden (1)
- concession (1)
- conductive argument (1)
- connection calculus (1)
- connective (1)
- connectivity (1)
- consistency (1)
- consistency checking (1)
- consistency measures (1)
- constraint (1)
- constraint programming (1)
- constraints (1)
- constructivism (1)
- construktivism (1)
- context-free grammar (1)
- context-sensitive (1)
- continuous (1)
- contrast (1)
- controlled vocabularies (1)
- corpus analysis (1)
- correlated errors (1)
- course timetabling (1)
- craters (1)
- crop (1)
- cryptography (1)
- cs4fn (1)
- curriculum theory (1)
- debugging (1)
- decidability questions (1)
- decision trees (1)
- declarative problem solving (1)
- deep learning (1)
- deep residual networks (1)
- degree of formality (1)
- degree of non-context-freeness (1)
- degree of non-regularity (1)
- degree of non-regulation (1)
- depression (1)
- design (1)
- design flow (1)
- design principles (1)
- design space exploration (1)
- determinism (1)
- detrending (1)
- developmental systems (1)
- diagnosis (1)
- didaktische Rekonstruktion (1)
- didaktisches Konzept (1)
- difference of Gaussians (1)
- digital circuit (1)
- digital design (1)
- digitale Bildung (1)
- digitale Hochschullehre (1)
- digitale Medien (1)
- digitally-enabled pedagogies (1)
- divide and conquer (1)
- domain-specific APIs (1)
- dropout (1)
- drug discovery (1)
- dynamic (1)
- dynamic classification (1)
- dynamic reconfiguration (1)
- dynamic service binding (1)
- dynamisch (1)
- dynamische Klassifikation (1)
- e-Learning (1)
- e-mentoring (1)
- eGovernment (1)
- eLectures (1)
- economic ripples (1)
- education and public policy (1)
- educational programming (1)
- educational reconstruction (1)
- educational systems (1)
- educational timetabling (1)
- edutainment (1)
- eingebettete Systeme (1)
- einseitige Kommunikation (1)
- email spam detection (1)
- emission factor (1)
- emotion (1)
- emotion representation (1)
- emotion research (1)
- endothelin (1)
- endothelin-converting enzyme (1)
- ensemble kalman filter (1)
- ensemble methods (1)
- enterprise search (1)
- entity alignment (1)
- enumeration (1)
- environments (1)
- epistemic logic programs (1)
- epistemic specifications (1)
- equality (1)
- error correction (1)
- error detection (1)
- error propagation (1)
- evaluation (1)
- event-related desynchronization (1)
- evidence theory (1)
- evolution (1)
- explicit negation (1)
- exponentiation (1)
- external ambiguity (1)
- external memory algorithms (1)
- extreme weather (1)
- eye movements (1)
- fading (1)
- fault tolerance (1)
- field-programmable gate array (1)
- finite model computation (1)
- finite state sequential transducers (1)
- flow-based bilateral filter (1)
- formal (1)
- formal argumentation systems (1)
- formalism (1)
- freie Daten (1)
- freie Software (1)
- fun (1)
- functions (1)
- gait (1)
- game based learning (1)
- game design elements (1)
- game-based learning (1)
- gap-filling (1)
- generalization (1)
- geometry generation (1)
- geospatial data (1)
- geospatial services (1)
- global constraints (1)
- globale Constraints (1)
- governance (1)
- gradient boosting (1)
- grammar (1)
- grammar inference (1)
- graph analysis (1)
- graph clustering (1)
- graph-based ranking (1)
- graph-search (1)
- greenhouse gas (1)
- hardware accelerator (1)
- hardware architecture (1)
- hardware design (1)
- hardware-software-codesign (1)
- high school (1)
- high-throughput analysis (1)
- higher (1)
- human-technology interaction (1)
- hybrid (1)
- hybrid semantic search (1)
- hybrid solving (1)
- hybride semantische Suche (1)
- hybrides Problemlösen (1)
- ice harboring (1)
- image (1)
- image classification (1)
- image data analysis (1)
- image recognition (1)
- imaging (1)
- impacts (1)
- incompleteness (1)
- inconsistency (1)
- incremental SVM (1)
- independent component analysis (1)
- indirect economic impacts (1)
- indirekte ökonomische Effekte (1)
- informal and formal learning (1)
- informal logic (1)
- informatics education (1)
- information and communication technologies (1)
- information extraction (1)
- information flow control (1)
- information retrieval (1)
- informatische Bildung im Sekundarbereich (1)
- infrastructure (1)
- innovation (1)
- input accuracy (1)
- interaction modeling (1)
- interaction techniques (1)
- interactive course (1)
- interactive workshop (1)
- internal ambiguity (1)
- intrusion detection (1)
- intuition (1)
- irradiation (1)
- joint lab (1)
- kernel PCA (1)
- kernel methods (1)
- key competences in physical computing (1)
- key competencies (1)
- kidney cancer (1)
- kinaesthetic teaching (1)
- klinisch-praktischer Unterricht (1)
- knowledge representation and reasoning (1)
- konvergente Dienste (1)
- landmarks (1)
- language design (1)
- latches (1)
- lautes Denken (1)
- leanCoP (1)
- learning (1)
- learning environment (1)
- lebenslanges Lernen (1)
- leftmost derivations (1)
- linear code (1)
- linear programming (1)
- linearer Code (1)
- linguistic (1)
- locomotion (1)
- logic (1)
- logic programming methodology and applications (1)
- logic synthesis (1)
- logic-based modeling (1)
- logical calculus (1)
- logical errors (1)
- logical signaling networks (1)
- logische Ergänzung (1)
- logische Fehler (1)
- logische Programmierung (1)
- logische Signalnetzwerke (1)
- loop formulas (1)
- loose programming (1)
- loss propagation (1)
- lunar exploration (1)
- machine learning algorithms (1)
- macro-economic modelling (1)
- makroökonomische Modellierung (1)
- malware detection (1)
- manipulation planning (1)
- map/reduce (1)
- maschninelles Lernen (1)
- mathematics education (1)
- measure development (1)
- media (1)
- mediated learning experience (1)
- medical (1)
- medizinisch (1)
- meta model (1)
- metabolic network (1)
- metabolism (1)
- metabolomics (1)
- metadata (1)
- metastasis (1)
- methodology (1)
- middleware (1)
- misconception (1)
- mixture models (1)
- mobile Applikationen (1)
- mobile devices (1)
- mobile learning (1)
- mobile technologies and apps (1)
- mobiles Lernen (1)
- mobiles lernen (1)
- model-based (1)
- model-driven architecture (1)
- modeling (1)
- molecular networks (1)
- molekulare Netzwerke (1)
- multi core data processing (1)
- multi-class classification (1)
- multiuser (1)
- natural disasters (1)
- natural language generation (1)
- navigation (1)
- neighborhood (1)
- network (1)
- networks (1)
- networks-on-chip (1)
- neue Online-Fehlererkennungsmethode (1)
- neural networks (1)
- neutral endopeptidase (1)
- nichtlineare ICA (1)
- nichtlineare PCA (NLPCA) (1)
- nichtlineare Projektionen (1)
- non-monotonic reasoning (1)
- nonlinear ICA (1)
- nonlinear PCA (NLPCA) (1)
- nonlinear projections (1)
- nonphotorealistic rendering (NPR) (1)
- o-ambiguity (1)
- objective difficulty (1)
- omega (1)
- on-chip (1)
- on-farm evaluation (1)
- one-sided communication (1)
- oneM2M (1)
- oneM2M Ontology (1)
- online assistance (1)
- ontologies (1)
- open learning (1)
- open source (1)
- operating system (1)
- optimization (1)
- organisational evolution (1)
- outlier detection (1)
- output space compaction (1)
- overcomplete ICA (1)
- pMOS radiation dosimeter (1)
- paper prototyping (1)
- parallel processing (1)
- parallel programming (1)
- parallel rewriting (1)
- parallel solving (1)
- parallele Programmierung (1)
- paralleles Lösen (1)
- parameter (1)
- parity aggregate operator (1)
- pattern recognition (1)
- pdf forms (1)
- pedagogy (1)
- personal (1)
- personal response systems (1)
- philosophical foundation of informatics pedagogy (1)
- philosophy of mathematics (1)
- physical Computing (1)
- physical computing tools (1)
- placement (1)
- planning (1)
- platform (1)
- plug-ins (1)
- policy making (1)
- portfolio-based solving (1)
- pre-primary level (1)
- prediction (1)
- predictive models (1)
- preferences (1)
- premise acceptability (1)
- preprocessing (1)
- primary education (1)
- primary level (1)
- priorities (1)
- probabilistic deep learning (1)
- probabilistic deep metric learning (1)
- probabilistische tiefe neuronale Netze (1)
- probabilistisches tiefes metrisches Lernen (1)
- problem-solving (1)
- process (1)
- process improvement (1)
- process model (1)
- process model alignment (1)
- process modeling (1)
- process modelling (1)
- process synchronization (1)
- professional development (1)
- professors (1)
- program encodings (1)
- programmed grammars (1)
- programming (1)
- programming in context (1)
- projection (1)
- proof (1)
- proof assistant (1)
- proof complexity (1)
- proof environment (1)
- propagation probability (1)
- prototype (1)
- proving (1)
- pruritus (1)
- pulse stretching inverters (1)
- quality of life (1)
- quantum (1)
- quantum cryptography (1)
- radiation hardness (1)
- radiation hardness design (1)
- railway network (1)
- random forest (1)
- real arguments (1)
- real-time (1)
- real-time application (1)
- real-time mapping (1)
- real-walking (1)
- reconfiguration (1)
- reference (1)
- referential effectiveness (1)
- regression (1)
- regular language (1)
- regulation (1)
- rekonfigurierbar (1)
- reliability analysis (1)
- reliability assessment (1)
- repair (1)
- resources (1)
- restricted parallelism (1)
- risk analysis (1)
- robust ICA (1)
- robuste ICA (1)
- safety (1)
- satisfiability (1)
- scheduling (1)
- search (1)
- secondary education (1)
- segmentation (1)
- selbstanpassendes Multiprozessorsystem (1)
- selbstprüfende Schaltungen (1)
- selection (1)
- selective fault tolerance (1)
- self-checking (1)
- self-efficacy (1)
- semantic domain modeling (1)
- semantic ranking (1)
- semantic search (1)
- semantic search evaluation (1)
- semantic search methods (1)
- semantic web (1)
- semantische Domänenmodellierung (1)
- semantische Suche (1)
- semantisches Netz (1)
- semantisches Ranking (1)
- sensitivity (1)
- service composition (1)
- shader (1)
- sign language (1)
- simplicity (1)
- single event upsets (1)
- single-event transient (1)
- single-trial-analysis (1)
- site-specific weed management (1)
- skeletonization (1)
- sleep quality (1)
- smart farming (1)
- smartphone (1)
- social media (1)
- socio-technical system (1)
- soft errors (1)
- software (1)
- software engineering (1)
- software-based cache coherence (1)
- sozio-technisches System (1)
- space missions (1)
- speed independence (1)
- stable model semantics (1)
- state complexity (1)
- static analysis (1)
- static prediction games (1)
- statistics program R (1)
- strahleninduzierte Einzelereignis-Effekte (1)
- strong equivalence (1)
- structured output prediction (1)
- strukturierte Vorhersage (1)
- student activation (1)
- student experience (1)
- student perceptions (1)
- students’ conceptions (1)
- students’ knowledge (1)
- study problems (1)
- stylization (1)
- sufficiency (1)
- suicidal ideations (1)
- supply chains (1)
- support vector machines (1)
- synthesis (1)
- systematic (1)
- systematisch (1)
- tableau calculi (1)
- tactic (1)
- teacher competencies (1)
- teachers (1)
- teaching (1)
- teaching informatics in general education (1)
- technical notes and rapid communications (1)
- technische Rahmenbedingungen (1)
- tele-teaching (1)
- temporary binding (1)
- terrain models (1)
- test response compaction (1)
- theory (1)
- theory of computation (1)
- think aloud (1)
- timing (1)
- tools for teaching (1)
- topics (1)
- touch input (1)
- tptp (1)
- tracing (1)
- transformation (1)
- transient Faults (1)
- transient analysis (1)
- triangulated irregular networks (1)
- triple modular redundancy (1)
- tutorial section (1)
- unfounded sets (1)
- unidirektionale Fehler (1)
- unification (1)
- university education (1)
- user experience (1)
- user interfaces (1)
- user-centred (1)
- video annotation (1)
- virtual 3D city model (1)
- virtual machine (1)
- virtual reality (1)
- weather extremes (1)
- wheat crops (1)
- work productivity (1)
- workflow management (1)
- xAPI (1)
- yellow rust (1)
- zero-aliasing (1)
- überbestimmte ICA (1)
- ‘unplugged’ computing (1)
Institute
- Institut für Informatik und Computational Science (1112)
- Hasso-Plattner-Institut für Digital Engineering gGmbH (19)
- Extern (7)
- Institut für Physik und Astronomie (2)
- Universitätsbibliothek (2)
- Zentrum für Qualitätsentwicklung in Lehre und Studium (ZfQ) (2)
- eLiS - E-Learning in Studienbereichen (2)
- Department Erziehungswissenschaft (1)
- Department Linguistik (1)
- Fachgruppe Betriebswirtschaftslehre (1)
Three quantum cryptographic protocols of multiuser quantum networks with embedded authentication, allowing quantum key distribution or quantum direct communication, are discussed in this work. The security of the protocols against different types of attacks is analysed with a focus on various impersonation attacks and the man-in-the-middle attack. On the basis of the security analyses several improvements are suggested and implemented in order to adjust the investigated vulnerabilities. Furthermore, the impact of the eavesdropping test procedure on impersonation attacks is outlined. The framework of a general eavesdropping test is proposed to provide additional protection against security risks in impersonation attacks.
Answer Set Programming (ASP) emerged in the late 1990s as a new logic programming paradigm, having its roots in nonmonotonic reasoning, deductive databases, and logic programming with negation as failure. The basic idea of ASP is to represent a computational problem as a logic program whose answer sets correspond to solutions, and then to use an answer set solver for finding answer sets of the program. ASP is particularly suited for solving NP-complete search problems. Among these, we find applications to product configuration, diagnosis, and graph-theoretical problems, e.g. finding Hamiltonian cycles. On different lines of ASP research, many extensions of the basic formalism have been proposed. The most intensively studied one is the modelling of preferences in ASP. They constitute a natural and effective way of selecting preferred solutions among a plethora of solutions for a problem. For example, preferences have been successfully used for timetabling, auctioning, and product configuration. In this thesis, we concentrate on preferences within answer set programming. Among several formalisms and semantics for preference handling in ASP, we concentrate on ordered logic programs with the underlying D-, W-, and B-semantics. In this setting, preferences are defined among rules of a logic program. They select preferred answer sets among (standard) answer sets of the underlying logic program. Up to now, those preferred answer sets have been computed either via a compilation method or by meta-interpretation. Hence, the question comes up, whether and how preferences can be integrated into an existing ASP solver. To solve this question, we develop an operational graph-based framework for the computation of answer sets of logic programs. Then, we integrate preferences into this operational approach. We empirically observe that our integrative approach performs in most cases better than the compilation method or meta-interpretation. Another research issue in ASP are optimization methods that remove redundancies, as also found in database query optimizers. For these purposes, the rather recently suggested notion of strong equivalence for ASP can be used. If a program is strongly equivalent to a subprogram of itself, then one can always use the subprogram instead of the original program, a technique which serves as an effective optimization method. Up to now, strong equivalence has not been considered for logic programs with preferences. In this thesis, we tackle this issue and generalize the notion of strong equivalence to ordered logic programs. We give necessary and sufficient conditions for the strong equivalence of two ordered logic programs. Furthermore, we provide program transformations for ordered logic programs and show in how far preferences can be simplified. Finally, we present two new applications for preferences within answer set programming. First, we define new procedures for group decision making, which we apply to the problem of scheduling a group meeting. As a second new application, we reconstruct a linguistic problem appearing in German dialects within ASP. Regarding linguistic studies, there is an ongoing debate about how unique the rule systems of language are in human cognition. The reconstruction of grammatical regularities with tools from computer science has consequences for this debate: if grammars can be modelled this way, then they share core properties with other non-linguistic rule systems.
Aufzählen von DNA-Codes
(2006)
In dieser Arbeit wird ein Modell zum Aufzählen von DNA-Codes entwickelt. Indem eine Ordnung auf der Menge aller DNA-Codewörter eingeführt und auf die Menge aller Codes erweitert wird, erlaubt das Modell das Auffinden von DNA-Codes mit bestimmten Eigenschaften, wie Überlappungsfreiheit, Konformität, Kommafreiheit, Stickyfreiheit, Überhangfreiheit, Teilwortkonformität und anderer bezüglich einer gegebenen Involution auf der Menge der Codewörter. Ein auf Grundlage des geschaffenen Modells entstandenes Werkzeug erlaubt das Suchen von Codes mit beliebigen Kombinationen von Codeeigenschaften. Ein weiterer wesentlicher Bestandteil dieser Arbeit ist die Untersuchung der Optimalität von DNA-Codes bezüglich ihrer Informationsrate sowie das Finden solider DNA-Codes.
Advances in biotechnologies rapidly increase the number of molecules of a cell which can be observed simultaneously. This includes expression levels of thousands or ten-thousands of genes as well as concentration levels of metabolites or proteins. Such Profile data, observed at different times or at different experimental conditions (e.g., heat or dry stress), show how the biological experiment is reflected on the molecular level. This information is helpful to understand the molecular behaviour and to identify molecules or combination of molecules that characterise specific biological condition (e.g., disease). This work shows the potentials of component extraction algorithms to identify the major factors which influenced the observed data. This can be the expected experimental factors such as the time or temperature as well as unexpected factors such as technical artefacts or even unknown biological behaviour. Extracting components means to reduce the very high-dimensional data to a small set of new variables termed components. Each component is a combination of all original variables. The classical approach for that purpose is the principal component analysis (PCA). It is shown that, in contrast to PCA which maximises the variance only, modern approaches such as independent component analysis (ICA) are more suitable for analysing molecular data. The condition of independence between components of ICA fits more naturally our assumption of individual (independent) factors which influence the data. This higher potential of ICA is demonstrated by a crossing experiment of the model plant Arabidopsis thaliana (Thale Cress). The experimental factors could be well identified and, in addition, ICA could even detect a technical artefact. However, in continuously observations such as in time experiments, the data show, in general, a nonlinear distribution. To analyse such nonlinear data, a nonlinear extension of PCA is used. This nonlinear PCA (NLPCA) is based on a neural network algorithm. The algorithm is adapted to be applicable to incomplete molecular data sets. Thus, it provides also the ability to estimate the missing data. The potential of nonlinear PCA to identify nonlinear factors is demonstrated by a cold stress experiment of Arabidopsis thaliana. The results of component analysis can be used to build a molecular network model. Since it includes functional dependencies it is termed functional network. Applied to the cold stress data, it is shown that functional networks are appropriate to visualise biological processes and thereby reveals molecular dynamics.
This thesis discusses challenges in IT security education, points out a gap between e-learning and practical education, and presents a work to fill the gap. E-learning is a flexible and personalized alternative to traditional education. Nonetheless, existing e-learning systems for IT security education have difficulties in delivering hands-on experience because of the lack of proximity. Laboratory environments and practical exercises are indispensable instruction tools to IT security education, but security education in conventional computer laboratories poses particular problems such as immobility as well as high creation and maintenance costs. Hence, there is a need to effectively transform security laboratories and practical exercises into e-learning forms. In this thesis, we introduce the Tele-Lab IT-Security architecture that allows students not only to learn IT security principles, but also to gain hands-on security experience by exercises in an online laboratory environment. In this architecture, virtual machines are used to provide safe user work environments instead of real computers. Thus, traditional laboratory environments can be cloned onto the Internet by software, which increases accessibility to laboratory resources and greatly reduces investment and maintenance costs. Under the Tele-Lab IT-Security framework, a set of technical solutions is also proposed to provide effective functionalities, reliability, security, and performance. The virtual machines with appropriate resource allocation, software installation, and system configurations are used to build lightweight security laboratories on a hosting computer. Reliability and availability of laboratory platforms are covered by a virtual machine management framework. This management framework provides necessary monitoring and administration services to detect and recover critical failures of virtual machines at run time. Considering the risk that virtual machines can be misused for compromising production networks, we present a security management solution to prevent the misuse of laboratory resources by security isolation at the system and network levels. This work is an attempt to bridge the gap between e-learning/tele-teaching and practical IT security education. It is not to substitute conventional teaching in laboratories but to add practical features to e-learning. This thesis demonstrates the possibility to implement hands-on security laboratories on the Internet reliably, securely, and economically.
With increasing number of applications in Internet and mobile environments, distributed software systems are demanded to be more powerful and flexible, especially in terms of dynamism and security. This dissertation describes my work concerning three aspects: dynamic reconfiguration of component software, security control on middleware applications, and web services dynamic composition. Firstly, I proposed a technology named Routing Based Workflow (RBW) to model the execution and management of collaborative components and realize temporary binding for component instances. The temporary binding means component instances are temporarily loaded into a created execution environment to execute their functions, and then are released to their repository after executions. The temporary binding allows to create an idle execution environment for all collaborative components, on which the change operations can be immediately carried out. The changes on execution environment will result in a new collaboration of all involved components, and also greatly simplifies the classical issues arising from dynamic changes, such as consistency preserving etc. To demonstrate the feasibility of RBW, I created a dynamic secure middleware system - the Smart Data Server Version 3.0 (SDS3). In SDS3, an open source implementation of CORBA is adopted and modified as the communication infrastructure, and three secure components managed by RBW, are created to enhance the security on the access of deployed applications. SDS3 offers multi-level security control on its applications from strategy control to application-specific detail control. For the management by RBW, the strategy control of SDS3 applications could be dynamically changed by reorganizing the collaboration of the three secure components. In addition, I created the Dynamic Services Composer (DSC) based on Apache open source projects, Apache Axis and WSIF. In DSC, RBW is employed to model the interaction and collaboration of web services and to enable the dynamic changes on the flow structure of web services. Finally, overall performance tests were made to evaluate the efficiency of the developed RBW and SDS3. The results demonstrated that temporary binding of component instances makes slight impacts on the execution efficiency of components, and the blackout time arising from dynamic changes can be extremely reduced in any applications.
The goal of a Brain-Computer Interface (BCI) consists of the development of a unidirectional interface between a human and a computer to allow control of a device only via brain signals. While the BCI systems of almost all other groups require the user to be trained over several weeks or even months, the group of Prof. Dr. Klaus-Robert Müller in Berlin and Potsdam, which I belong to, was one of the first research groups in this field which used machine learning techniques on a large scale. The adaptivity of the processing system to the individual brain patterns of the subject confers huge advantages for the user. Thus BCI research is considered a hot topic in machine learning and computer science. It requires interdisciplinary cooperation between disparate fields such as neuroscience, since only by combining machine learning and signal processing techniques based on neurophysiological knowledge will the largest progress be made. In this work I particularly deal with my part of this project, which lies mainly in the area of computer science. I have considered the following three main points: <b>Establishing a performance measure based on information theory:</b> I have critically illuminated the assumptions of Shannon's information transfer rate for application in a BCI context. By establishing suitable coding strategies I was able to show that this theoretical measure approximates quite well to what is practically achieveable. <b>Transfer and development of suitable signal processing and machine learning techniques:</b> One substantial component of my work was to develop several machine learning and signal processing algorithms to improve the efficiency of a BCI. Based on the neurophysiological knowledge that several independent EEG features can be observed for some mental states, I have developed a method for combining different and maybe independent features which improved performance. In some cases the performance of the combination algorithm outperforms the best single performance by more than 50 %. Furthermore, I have theoretically and practically addressed via the development of suitable algorithms the question of the optimal number of classes which should be used for a BCI. It transpired that with BCI performances reported so far, three or four different mental states are optimal. For another extension I have combined ideas from signal processing with those of machine learning since a high gain can be achieved if the temporal filtering, i.e., the choice of frequency bands, is automatically adapted to each subject individually. <b>Implementation of the Berlin brain computer interface and realization of suitable experiments:</b> Finally a further substantial component of my work was to realize an online BCI system which includes the developed methods, but is also flexible enough to allow the simple realization of new algorithms and ideas. So far, bitrates of up to 40 bits per minute have been achieved with this system by absolutely untrained users which, compared to results of other groups, is highly successful.
Modern biological analysis techniques supply scientists with various forms of data. One category of such data are the so called "expression data". These data indicate the quantities of biochemical compounds present in tissue samples. Recently, expression data can be generated at a high speed. This leads in turn to amounts of data no longer analysable by classical statistical techniques. Systems biology is the new field that focuses on the modelling of this information. At present, various methods are used for this purpose. One superordinate class of these methods is machine learning. Methods of this kind had, until recently, predominantly been used for classification and prediction tasks. This neglected a powerful secondary benefit: the ability to induce interpretable models. Obtaining such models from data has become a key issue within Systems biology. Numerous approaches have been proposed and intensively discussed. This thesis focuses on the examination and exploitation of one basic technique: decision trees. The concept of comparing sets of decision trees is developed. This method offers the possibility of identifying significant thresholds in continuous or discrete valued attributes through their corresponding set of decision trees. Finding significant thresholds in attributes is a means of identifying states in living organisms. Knowing about states is an invaluable clue to the understanding of dynamic processes in organisms. Applied to metabolite concentration data, the proposed method was able to identify states which were not found with conventional techniques for threshold extraction. A second approach exploits the structure of sets of decision trees for the discovery of combinatorial dependencies between attributes. Previous work on this issue has focused either on expensive computational methods or the interpretation of single decision trees a very limited exploitation of the data. This has led to incomplete or unstable results. That is why a new method is developed that uses sets of decision trees to overcome these limitations. Both the introduced methods are available as software tools. They can be applied consecutively or separately. That way they make up a package of analytical tools that usefully supplement existing methods. By means of these tools, the newly introduced methods were able to confirm existing knowledge and to suggest interesting and new relationships between metabolites.
Quantified Boolean formulas (QBFs) play an important role in theoretical computer science. QBF extends propositional logic in such a way that many advanced forms of reasoning can be easily formulated and evaluated. In this dissertation we present our ZQSAT, which is an algorithm for evaluating quantified Boolean formulas. ZQSAT is based on ZBDD: Zero-Suppressed Binary Decision Diagram , which is a variant of BDD, and an adopted version of the DPLL algorithm. It has been implemented in C using the CUDD: Colorado University Decision Diagram package. The capability of ZBDDs in storing sets of subsets efficiently enabled us to store the clauses of a QBF very compactly and let us to embed the notion of memoization to the DPLL algorithm. These points led us to implement the search algorithm in such a way that we could store and reuse the results of all previously solved subformulas with a little overheads. ZQSAT can solve some sets of standard QBF benchmark problems (known to be hard for DPLL based algorithms) faster than the best existing solvers. In addition to prenex-CNF, ZQSAT accepts prenex-NNF formulas. We show and prove how this capability can be exponentially beneficial.
Thema dieser Arbeit sind echtzeitfähige 3D-Renderingverfahren, die 3D-Geometrie mit über der Standarddarstellung hinausgehenden Qualitäts- und Gestaltungsmerkmalen rendern können. Beispiele sind Verfahren zur Darstellung von Schatten, Reflexionen oder Transparenz. Mit heutigen computergraphischen Software-Basissystemen ist ihre Integration in 3D-Anwendungssysteme sehr aufwändig: Dies liegt einerseits an der technischen, algorithmischen Komplexität der Einzelverfahren, andererseits an Ressourcenkonflikten und Seiteneffekten bei der Kombination mehrerer Verfahren. Szenengraphsysteme, intendiert als computergraphische Softwareschicht zur Abstraktion von der Graphikhardware, stellen derzeit keine Mechanismen zur Nutzung dieser Renderingverfahren zur Verfügung. Ziel dieser Arbeit ist es, eine Software-Architektur für ein Szenengraphsystem zu konzipieren und umzusetzen, die echtzeitfähige 3D-Renderingverfahren als Komponenten modelliert und es damit erlaubt, diese Verfahren innerhalb des Szenengraphsystems für die Anwendungsentwicklung effektiv zu nutzen. Ein Entwickler, der ein solches Szenengraphsystem nutzt, steuert diese Komponenten durch Elemente in der Szenenbeschreibung an, die die sichtbare Wirkung eines Renderingverfahrens auf die Geometrie in der Szene angeben, aber keine Hinweise auf die algorithmische Implementierung des Verfahrens enthalten. Damit werden Renderingverfahren in 3D-Anwendungssystemen nutzbar, ohne dass ein Entwickler detaillierte Kenntnisse über sie benötigt, so dass der Aufwand für ihre Entwicklung drastisch reduziert wird. Ein besonderer Augenmerk der Arbeit liegt darauf, auf diese Weise auch verschiedene Renderingverfahren in einer Szene kombiniert einsetzen zu können. Hierzu ist eine Unterteilung der Renderingverfahren in mehrere Kategorien erforderlich, die mit Hilfe unterschiedlicher Ansätze ausgewertet werden. Dies erlaubt die Abstimmung verschiedener Komponenten für Renderingverfahren und ihrer verwendeten Ressourcen. Die Zusammenarbeit mehrerer Renderingverfahren hat dort ihre Grenzen, wo die Kombination von Renderingverfahren graphisch nicht sinnvoll ist oder fundamentale technische Beschränkungen der Verfahren eine gleichzeitige Verwendung unmöglich machen. Die in dieser Arbeit vorgestellte Software-Architektur kann diese Grenzen nicht verschieben, aber sie ermöglicht den gleichzeitigen Einsatz vieler Verfahren, bei denen eine Kombination aufgrund der hohen Komplexität der Implementierung bislang nicht erreicht wurde. Das Vermögen zur Zusammenarbeit ist dabei allerdings von der Art eines Einzelverfahrens abhängig: Verfahren zur Darstellung transparenter Geometrie beispielsweise erfordern bei der Kombination mit anderen Verfahren in der Regel vollständig neuentwickelte Renderingverfahren; entsprechende Komponenten für das Szenengraphsystem können daher nur eingeschränkt mit Komponenten für andere Renderingverfahren verwendet werden. Das in dieser Arbeit entwickelte System integriert und kombiniert Verfahren zur Darstellung von Bumpmapping, verschiedene Schatten- und Reflexionsverfahren sowie bildbasiertes CSG-Rendering. Damit stehen wesentliche Renderingverfahren in einem Szenengraphsystem erstmalig komponentenbasiert und auf einem hohen Abstraktionsniveau zur Verfügung. Das System ist trotz des zusätzlichen Verwaltungsaufwandes in der Lage, die Renderingverfahren einzeln und in Kombination grundsätzlich in Echtzeit auszuführen.
Mit zunehmender Komplexität technischer Softwaresysteme ist die Nachfrage an produktiveren Methoden und Werkzeugen auch im sicherheitskritischen Umfeld gewachsen. Da insbesondere objektorientierte und modellbasierte Ansätze und Methoden ausgezeichnete Eigenschaften zur Entwicklung großer und komplexer Systeme besitzen, ist zu erwarten, dass diese in naher Zukunft selbst bis in sicherheitskritische Bereiche der Softwareentwicklung vordringen. Mit der Unified Modeling Language Real-Time (UML-RT) wird eine Softwareentwicklungsmethode für technische Systeme durch die Object Management Group (OMG) propagiert. Für den praktischen Einsatz im technischen und sicherheitskritischen Umfeld muss diese Methode nicht nur bestimmte technische Eigenschaften, beispielsweise temporale Analysierbarkeit, besitzen, sondern auch in einen bestehenden Qualitätssicherungsprozess integrierbar sein. Ein wichtiger Aspekt der Integration der UML-RT in ein qualitätsorientiertes Prozessmodell, beispielsweise in das V-Modell, ist die Verfügbarkeit von ausgereiften Konzepten und Methoden für einen systematischen Modultest. Der Modultest dient als erste Qualititätssicherungsphase nach der Implementierung der Fehlerfindung und dem Qualitätsnachweis für jede separat prüfbare Softwarekomponente eines Systems. Während dieser Phase stellt die Durchführung von systematischen Tests die wichtigste Qualitätssicherungsmaßnahme dar. Während zum jetzigen Zeitpunkt zwar ausgereifte Methoden und Werkzeuge für die modellbasierte Softwareentwicklung zur Verfügung stehen, existieren nur wenig überzeugende Lösungen für eine systematische modellbasierte Modulprüfung. Die durchgängige Verwendung ausführbarer Modelle und Codegenerierung stellen wesentliche Konzepte der modellbasierten Softwareentwicklung dar. Sie dienen der konstruktiven Fehlerreduktion durch Automatisierung ansonsten fehlerträchtiger, manueller Vorgänge. Im Rahmen einer modellbasierten Qualitätssicherung sollten diese Konzepte konsequenterweise in die späteren Qualitätssicherungsphasen transportiert werden. Daher ist eine wesentliche Forderung an ein Verfahren zur modellbasierten Modulprüfung ein möglichst hoher Grad an Automatisierung. In aktuellen Entwicklungen hat sich für die Generierung von Testfällen auf Basis von Zustandsautomaten die Verwendung von Model Checking als effiziente und an die vielfältigsten Testprobleme anpassbare Methode bewährt. Der Ansatz des Model Checking stammt ursprünglich aus dem Entwurf von Kommunikationsprotokollen und wurde bereits erfolgreich auf verschiedene Probleme der Modellierung technischer Software angewendet. Insbesondere in der Gegenwart ausführbarer, automatenbasierter Modelle erscheint die Verwendung von Model Checking sinnvoll, das die Existenz einer formalen, zustandsbasierten Spezifikation voraussetzt. Ein ausführbares, zustandsbasiertes Modell erfüllt diese Anforderungen in der Regel. Aus diesen Gründen ist die Wahl eines Model Checking Ansatzes für die Generierung von Testfällen im Rahmen eines modellbasierten Modultestverfahrens eine logische Konsequenz. Obwohl in der aktuellen Spezifikation der UML-RT keine eindeutigen Aussagen über den zur Verhaltensbeschreibung zu verwendenden Formalismus gemacht werden, ist es wahrscheinlich, dass es sich bei der UML-RT um eine zu Real-Time Object-Oriented Modeling (ROOM) kompatible Methode handelt. Alle in dieser Arbeit präsentierten Methoden und Ergebnisse sind somit auf die kommende UML-RT übertragbar und von sehr aktueller Bedeutung. Aus den genannten Gründen verfolgt diese Arbeit das Ziel, die analytische Qualitätssicherung in der modellbasierten Softwareentwicklung mittels einer modellbasierten Methode für den Modultest zu verbessern. Zu diesem Zweck wird eine neuartige Testmethode präsentiert, die auf automatenbasierten Verhaltensmodellen und CTL Model Checking basiert. Die Testfallgenerierung kann weitgehend automatisch erfolgen, um Fehler durch menschlichen Einfluss auszuschließen. Das entwickelte Modultestverfahren ist in die technischen Konzepte Model Driven Architecture und ROOM, beziehungsweise UML-RT, sowie in die organisatorischen Konzepte eines qualitätsorientierten Prozessmodells, beispielsweise das V-Modell, integrierbar.
Entwickelt wird ein Dokument Management System zur elektronischen, Client-Server-basierten Publikation und Langzeitarchivierung von Hochschulschriften für die Universitätsbibliothek Potsdam. Der zu konzipierende Dokumentenserver muss den bibliothekarischen Anforderungen im Hinblick auf die Sicherung von Authentizität und Integrität des Servers und der einzelnen Textdokumente entsprechen. Eine Analyse der Eignung verbreiteter Dateiformate zur dauerhaften Speicherung unter Berücksichtigung von Verfügbarkeit, Strukturierbarkeit, Konvertierbarkeit und Austauschbarkeit sowie Recherchierbarkeit erbringt eine langfristig anzustrebende Präferenz für XML als Archivierungs- und Rechercheformat sowie PDF und/oder HTML als Präsentationsformate. Die Formalerfassung erfolgt über die Anreicherung des Dokumentes mit Metadaten nach dem DC qualified Standard, die in einer Datenbank strukturiert abgelegt sind. Der dauerhafte Zugang zur Publikation kann durch Verwendung einer zitierfähigen URN (Persistent Identifier) gesichert werden. Bestehende Archivierungssysteme werden untersucht und auf Vereinbarkeit mit den lokalen Bedürfnissen geprüft. Ein Workflow für die Anlieferung von Dokument und beschreibenden Metadaten durch den Autor und die weitere Bearbeitung durch die Bibliothek wird erarbeitet und die technische Umsetzung mittels Perl, HTML, XML und einer MS Access Datenbank beschrieben. Der Dokumentenserver ermöglicht performantes Retrieval und ist als Dataprovider mit einer OAI-Schnittstelle für den weltweiten, standardisierten Datenaustausch ausgestattet. Das System kann in wissenschaftlichen Informationseinrichtungen als Internet- oder Intranet-Repositorium eingesetzt werden. (Fremdreferat)
This thesis is concerned with the solution of the blind source separation problem (BSS). The BSS problem occurs frequently in various scientific and technical applications. In essence, it consists in separating meaningful underlying components out of a mixture of a multitude of superimposed signals. In the recent research literature there are two related approaches to the BSS problem: The first is known as Independent Component Analysis (ICA), where the goal is to transform the data such that the components become as independent as possible. The second is based on the notion of diagonality of certain characteristic matrices derived from the data. Here the goal is to transform the matrices such that they become as diagonal as possible. In this thesis we study the latter method of approximate joint diagonalization (AJD) to achieve a solution of the BSS problem. After an introduction to the general setting, the thesis provides an overview on particular choices for the set of target matrices that can be used for BSS by joint diagonalization. As the main contribution of the thesis, new algorithms for approximate joint diagonalization of several matrices with non-orthogonal transformations are developed. These newly developed algorithms will be tested on synthetic benchmark datasets and compared to other previous diagonalization algorithms. Applications of the BSS methods to biomedical signal processing are discussed and exemplified with real-life data sets of multi-channel biomagnetic recordings.
Die Dissertation stellt eine neue Herangehensweise an die Lösung der Aufgabe der funktionalen Diagnostik digitaler Systeme vor. In dieser Arbeit wird eine neue Methode für die Fehlererkennung vorgeschlagen, basierend auf der Logischen Ergänzung und der Verwendung von Berger-Codes und dem 1-aus-3 Code. Die neue Fehlererkennungsmethode der Logischen Ergänzung gestattet einen hohen Optimierungsgrad der benötigten Realisationsfläche der konstruierten Fehlererkennungsschaltungen. Außerdem ist eins der wichtigen in dieser Dissertation gelösten Probleme die Synthese vollständig selbstprüfender Schaltungen.
Interaktive System sind dynamische Systeme mit einem zumeist informationellen Kern, die über eine Benutzungsschnittstelle von einem oder mehreren Benutzern bedient werden können. Grundlage für die Benutzung interaktiver Systeme ist das Verständnis von Zweck und Funktionsweise. Allein aus Form und Gestalt der Benutzungsschnittstelle ergibt sich ein solches Verständnis nur in einfachen Fällen. Mit steigender Komplexität ist daher eine verständliche Beschreibung solcher Systeme für deren Entwicklung und Benutzung unverzichtbar. Abhängig von ihrem Zweck variieren die Formen vorgefundener Beschreibungen in der Literatur sehr stark. Ausschlaggebend für die Verständlichkeit einer Beschreibung ist jedoch primär die ihr zugrundeliegende Begriffswelt. Zur Beschreibung allgemeiner komplexer diskreter Systeme - aufbauend auf einer getrennten Betrachtung von Aufbau-, Ablauf- und Wertestrukturen - existiert eine bewährte Begriffswelt. Eine Spezialisierung dieser Begriffs- und Vorstellungswelt, die den unterschiedlichen Betrachtungsebenen interaktiver Systeme gerecht wird und die als Grundlage beliebiger Beschreibungsansätze interaktiver Systeme dienen kann, gibt es bisher nicht. Ziel dieser Arbeit ist die Bereitstellung einer solchen Begriffswelt zur effizienten Kommunikation der Strukturen interaktiver Systeme. Dadurch soll die Grundlage für eine sinnvolle Ergänzung bestehender Beschreibungs- und Entwicklungsansätze geschaffen werden. Prinzipien der Gestaltung von Benutzungsschnittstellen, Usability- oder Ergonomiebetrachtungen stehen nicht im Mittelpunkt der Arbeit. Ausgehend von der informationellen Komponente einer Benutzungsschnittstelle werden drei Modellebenen abgegrenzt, die bei der Betrachtung eines interaktiven Systems zu unterscheiden sind. Jede Modellebene ist durch eine typische Begriffswelt gekennzeichnet, die ihren Ursprung in einer aufbauverwurzelten Vorstellung hat. Der durchgängige Bezug auf eine Systemvorstellung unterscheidet diesen Ansatz von dem bereits bekannten Konzept der Abgrenzung unterschiedlicher Ebenen verschiedenartiger Entwurfsentscheidungen. Die Fundamental Modeling Concepts (FMC) bilden dabei die Grundlage für die Findung und die Darstellung von Systemstrukturen. Anhand bestehender Systembeschreibungen wird gezeigt, wie die vorgestellte Begriffswelt zur Modellfindung genutzt werden kann. Dazu wird eine repräsentative Auswahl vorgefundener Systembeschreibungen aus der einschlägigen Literatur daraufhin untersucht, in welchem Umfang durch sie die Vorstellungswelt dynamischer Systeme zum Ausdruck kommt. Defizite in der ursprünglichen Darstellung werden identifiziert. Anhand von Alternativmodellen zu den betrachteten Systemen wird der Nutzen der vorgestellten Begriffswelt und Darstellungsweise demonstriert.
Zur Beherrschung großer Systeme, insbesondere zur Weitergabe und Nutzung von Erfahrungswissen in der frühen Entwurfs- und Planungsphase, benötigt man Abstraktionen für deren Strukturen. Trennt man Software- von Systemstrukturen, kann man mit letzteren Systeme auf ausreichend hohem Abstraktionsgrad beschreiben.Software-Patterns dienen dazu, Erfahrungswissen bezüglich programmierter Systeme strukturiert weiterzugeben. Dabei wird unterschieden zwischen Idiomen, die sich auf Lösungen mit einer bestimmten Programmiersprache beziehen, Design-Patterns, die nur einen kleinen Teil des Programms betreffen und Architektur-Patterns, deren Einfluss über einen größeren Teil oder gar das komplette Programm reicht. Eine Untersuchung von existierenden Patterns zeigt, dass deren Konzepte nützlich zum Finden von Systemstrukturen sind. Die grafische Darstellung dieser Patterns ist dagegen oft auf Software-Strukturen eingeschränkt und ist für die Vermittlung von Erfahrungen zum Finden von Systemstrukturen meist nicht geeignet. Daher wird die Kategorie der konzeptionellen Patterns mit einer darauf abgestimmten grafischen Darstellungsform vorgeschlagen, bei denen Problem und Lösungsvorschlag im Bereich der Systemstrukturen liegen. Sie betreffen informationelle Systeme, sind aber nicht auf Lösungen mit Software beschränkt. Die Systemstrukturen werden grafisch dargestellt, wobei dafür die Fundamental Modeling Concepts (FMC) verwendet werden, die zur Darstellung von Systemstrukturen entwickelt wurden.
Independent component analysis (ICA) is a tool for statistical data analysis and signal processing that is able to decompose multivariate signals into their underlying source components. Although the classical ICA model is highly useful, there are many real-world applications that require powerful extensions of ICA. This thesis presents new methods that extend the functionality of ICA: (1) reliability and grouping of independent components with noise injection, (2) robust and overcomplete ICA with inlier detection, and (3) nonlinear ICA with kernel methods.
Gerade in den letzten Jahren erfuhr Open Source Software (OSS) eine zunehmende Verbreitung und Popularität und hat sich in verschiedenen Anwendungsdomänen etabliert. Die Prozesse, welche sich im Kontext der OSS-Entwicklung (auch: OSSD – Open Source Software-Development) evolutionär herausgebildet haben, weisen in den verschiedenen OSS-Entwicklungsprojekten z.T. ähnliche Eigenschaften und Strukturen auf und auch die involvierten Entitäten, wie z.B. Artefakte, Rollen oder Software-Werkzeuge sind weitgehend miteinander vergleichbar. Dies motiviert den Gedanken, ein verallgemeinerbares Modell zu entwickeln, welches die generalisierbaren Entwicklungsprozesse im Kontext von OSS zu einem übertragbaren Modell abstrahiert. Auch in der Wissenschaftsdisziplin des Software Engineering (SE) wurde bereits erkannt, dass sich der OSSD-Ansatz in verschiedenen Aspekten erheblich von klassischen (proprietären) Modellen des SE unterscheidet und daher diese Methoden einer eigenen wissenschaftlichen Betrachtung bedürfen. In verschiedenen Publikationen wurden zwar bereits einzelne Aspekte der OSS-Entwicklung analysiert und Theorien über die zugrundeliegenden Entwicklungsmethoden formuliert, aber es existiert noch keine umfassende Beschreibung der typischen Prozesse der OSSD-Methodik, die auf einer empirischen Untersuchung existierender OSS-Entwicklungsprojekte basiert. Da dies eine Voraussetzung für die weitere wissenschaftliche Auseinandersetzung mit OSSD-Prozessen darstellt, wird im Rahmen dieser Arbeit auf der Basis vergleichender Fallstudien ein deskriptives Modell der OSSD-Prozesse hergeleitet und mit Modellierungselementen der UML formalisiert beschrieben. Das Modell generalisiert die identifizierten Prozesse, Prozessentitäten und Software-Infrastrukturen der untersuchten OSSD-Projekte. Es basiert auf einem eigens entwickelten Metamodell, welches die zu analysierenden Entitäten identifiziert und die Modellierungssichten und -elemente beschreibt, die zur UML-basierten Beschreibung der Entwicklungsprozesse verwendet werden. In einem weiteren Arbeitsschritt wird eine weiterführende Analyse des identifizierten Modells durchgeführt, um Implikationen, und Optimierungspotentiale aufzuzeigen. Diese umfassen beispielsweise die ungenügende Plan- und Terminierbarkeit von Prozessen oder die beobachtete Tendenz von OSSD-Akteuren, verschiedene Aktivitäten mit unterschiedlicher Intensität entsprechend der subjektiv wahrgenommenen Anreize auszuüben, was zur Vernachlässigung einiger Prozesse führt. Anschließend werden Optimierungszielstellungen dargestellt, die diese Unzulänglichkeiten adressieren, und ein Optimierungsansatz zur Verbesserung des OSSD-Modells wird beschrieben. Dieser Ansatz umfasst die Erweiterung der identifizierten Rollen, die Einführung neuer oder die Erweiterung bereits identifizierter Prozesse und die Modifikation oder Erweiterung der Artefakte des generalisierten OSS-Entwicklungsmodells. Die vorgestellten Modellerweiterungen dienen vor allem einer gesteigerten Qualitätssicherung und der Kompensation von vernachlässigten Prozessen, um sowohl die entwickelte Software- als auch die Prozessqualität im OSSD-Kontext zu verbessern. Desweiteren werden Softwarefunktionalitäten beschrieben, welche die identifizierte bestehende Software-Infrastruktur erweitern und eine gesamtheitlichere, softwaretechnische Unterstützung der OSSD-Prozesse ermöglichen sollen. Abschließend werden verschiedene Anwendungsszenarien der Methoden des OSS-Entwicklungsmodells, u.a. auch im kommerziellen SE, identifiziert und ein Implementierungsansatz basierend auf der OSS GENESIS vorgestellt, der zur Implementierung und Unterstützung des OSSD-Modells verwendet werden kann.
In recent years, there has been a dramatic increase in available compute capacities. However, these “Grid resources” are rarely accessible in a continuous stream, but rather appear scattered across various machine types, platforms and operating systems, which are coupled by networks of fluctuating bandwidth. It becomes increasingly difficult for scientists to exploit available resources for their applications. We believe that intelligent, self-governing applications should be able to select resources in a dynamic and heterogeneous environment: Migrating applications determine a resource when old capacities are used up. Spawning simulations launch algorithms on external machines to speed up the main execution. Applications are restarted as soon as a failure is detected. All these actions can be taken without human interaction. A distributed compute environment possesses an intrinsic unreliability. Any application that interacts with such an environment must be able to cope with its failing components: deteriorating networks, crashing machines, failing software. We construct a reliable service infrastructure by endowing a service environment with a peer-to-peer topology. This “Grid Peer Services” infrastructure accommodates high-level services like migration and spawning, as well as fundamental services for application launching, file transfer and resource selection. It utilizes existing Grid technology wherever possible to accomplish its tasks. An Application Information Server acts as a generic information registry to all participants in a service environment. The service environment that we developed, allows applications e.g. to send a relocation requests to a migration server. The server selects a new computer based on the transmitted resource requirements. It transfers the application's checkpoint and binary to the new host and resumes the simulation. Although the Grid's underlying resource substrate is not continuous, we achieve persistent computations on Grids by relocating the application. We show with our real-world examples that a traditional genome analysis program can be easily modified to perform self-determined migrations in this service environment.
In order to face the rapidly increasing need for computational resources of various scientific and engineering applications one has to think of new ways to make more efficient use of the worlds current computational resources. In this respect, the growing speed of wide area networks made a new kind of distributed computing possible: Metacomputing or (distributed) Grid computing. This is a rather new and uncharted field in computational science. The rapidly increasing speed of networks even outperforms the average increase of processor speed: Processor speeds double on average each 18 month whereas network bandwidths double every 9 months. Due to this development of local and wide area networks Grid computing will certainly play a key role in the future of parallel computing. This type of distributed computing, however, distinguishes from the traditional parallel computing in many ways since it has to deal with many problems not occurring in classical parallel computing. Those problems are for example heterogeneity, authentication and slow networks to mention only a few. Some of those problems, e.g. the allocation of distributed resources along with the providing of information about these resources to the application have been already attacked by the Globus software. Unfortunately, as far as we know, hardly any application or middle-ware software takes advantage of this information, since most parallelizing algorithms for finite differencing codes are implicitly designed for single supercomputer or cluster execution. We show that although it is possible to apply classical parallelizing algorithms in a Grid environment, in most cases the observed efficiency of the executed code is very poor. In this work we are closing this gap. In our thesis, we will - show that an execution of classical parallel codes in Grid environments is possible but very slow - analyze this situation of bad performance, nail down bottlenecks in communication, remove unnecessary overhead and other reasons for low performance - develop new and advanced algorithms for parallelisation that are aware of a Grid environment in order to generelize the traditional parallelization schemes - implement and test these new methods, replace and compare with the classical ones - introduce dynamic strategies that automatically adapt the running code to the nature of the underlying Grid environment. The higher the performance one can achieve for a single application by manual tuning for a Grid environment, the lower the chance that those changes are widely applicable to other programs. In our analysis as well as in our implementation we tried to keep the balance between high performance and generality. None of our changes directly affect code on the application level which makes our algorithms applicable to a whole class of real world applications. The implementation of our work is done within the Cactus framework using the Globus toolkit, since we think that these are the most reliable and advanced programming frameworks for supporting computations in Grid environments. On the other hand, however, we tried to be as general as possible, i.e. all methods and algorithms discussed in this thesis are independent of Cactus or Globus.
In this work we consider statistical learning problems. A learning machine aims to extract information from a set of training examples such that it is able to predict the associated label on unseen examples. We consider the case where the resulting classification or regression rule is a combination of simple rules - also called base hypotheses. The so-called boosting algorithms iteratively find a weighted linear combination of base hypotheses that predict well on unseen data. We address the following issues: o The statistical learning theory framework for analyzing boosting methods. We study learning theoretic guarantees on the prediction performance on unseen examples. Recently, large margin classification techniques emerged as a practical result of the theory of generalization, in particular Boosting and Support Vector Machines. A large margin implies a good generalization performance. Hence, we analyze how large the margins in boosting are and find an improved algorithm that is able to generate the maximum margin solution. o How can boosting methods be related to mathematical optimization techniques? To analyze the properties of the resulting classification or regression rule, it is of high importance to understand whether and under which conditions boosting converges. We show that boosting can be used to solve large scale constrained optimization problems, whose solutions are well characterizable. To show this, we relate boosting methods to methods known from mathematical optimization, and derive convergence guarantees for a quite general family of boosting algorithms. o How to make Boosting noise robust? One of the problems of current boosting techniques is that they are sensitive to noise in the training sample. In order to make boosting robust, we transfer the soft margin idea from support vector learning to boosting. We develop theoretically motivated regularized algorithms that exhibit a high noise robustness. o How to adapt boosting to regression problems? Boosting methods are originally designed for classification problems. To extend the boosting idea to regression problems, we use the previous convergence results and relations to semi-infinite programming to design boosting-like algorithms for regression problems. We show that these leveraging algorithms have desirable theoretical and practical properties. o Can boosting techniques be useful in practice? The presented theoretical results are guided by simulation results either to illustrate properties of the proposed algorithms or to show that they work well in practice. We report on successful applications in a non-intrusive power monitoring system, chaotic time series analysis and a drug discovery process. --- Anmerkung: Der Autor ist Träger des von der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam vergebenen Michelson-Preises für die beste Promotion des Jahres 2001/2002.
The objective of this thesis is to provide new space compaction techniques for testing or concurrent checking of digital circuits. In particular, the work focuses on the design of space compactors that achieve high compaction ratio and minimal loss of testability of the circuits. In the first part, the compactors are designed for combinational circuits based on the knowledge of the circuit structure. Several algorithms for analyzing circuit structures are introduced and discussed for the first time. The complexity of each design procedure is linear with respect to the number of gates of the circuit. Thus, the procedures are applicable to large circuits. In the second part, the first structural approach for output compaction for sequential circuits is introduced. Essentially, it enhances the first part. For the approach introduced in the third part it is assumed that the structure of the circuit and the underlying fault model are unknown. The space compaction approach requires only the knowledge of the fault-free test responses for a precomputed test set. The proposed compactor design guarantees zero-aliasing with respect to the precomputed test set.