004 Datenverarbeitung; Informatik
Refine
Has Fulltext
- yes (207) (remove)
Year of publication
Document Type
- Article (110)
- Doctoral Thesis (64)
- Conference Proceeding (13)
- Master's Thesis (8)
- Postprint (6)
- Monograph/Edited Volume (2)
- Bachelor Thesis (1)
- Habilitation Thesis (1)
- Moving Images (1)
- Preprint (1)
Keywords
- Informatik (17)
- Didaktik (15)
- Hochschuldidaktik (14)
- Ausbildung (13)
- Maschinelles Lernen (7)
- Antwortmengenprogrammierung (5)
- Computer Science Education (5)
- Machine Learning (5)
- answer set programming (5)
- E-Learning (4)
- education (4)
- higher education (4)
- Answer Set Programming (3)
- Competence Measurement (3)
- DPLL (3)
- Informatikdidaktik (3)
- Secondary Education (3)
- didactics (3)
- informatics (3)
- Algorithmen (2)
- Algorithms (2)
- Assessment (2)
- Automatisches Beweisen (2)
- Big Data (2)
- Bildverarbeitung (2)
- Code (2)
- Competence Modelling (2)
- Computational thinking (2)
- Computer Science (2)
- Computergrafik (2)
- Computersicherheit (2)
- Constraint Solving (2)
- Data Privacy (2)
- Deduction (2)
- EEG (2)
- FMC (2)
- HCI (2)
- ICA (2)
- Informatics (2)
- Informatics Education (2)
- Informatics Modelling (2)
- Informatics System Application (2)
- Informatics System Comprehension (2)
- Informatikstudium (2)
- Key Competencies (2)
- Klausellernen (2)
- Knowledge Representation and Reasoning (2)
- Künstliche Intelligenz (2)
- Logic Programming (2)
- Logics (2)
- Mensch-Computer-Interaktion (2)
- Modell (2)
- Modellierung (2)
- Ontologie (2)
- Optimization (2)
- Planing (2)
- Prozessmodellierung (2)
- Relevanz (2)
- SAT (2)
- Semantic Web (2)
- Systemstruktur (2)
- Texturen (2)
- Theorembeweisen (2)
- Unifikation (2)
- Visualisierung (2)
- Vorhersage (2)
- abstraction (2)
- code (2)
- complexity (2)
- computational thinking (2)
- computer graphics (2)
- computer science education (2)
- human computer interaction (2)
- image processing (2)
- machine learning (2)
- model (2)
- non-photorealistic rendering (2)
- relevance (2)
- systems biology (2)
- textures (2)
- theorem (2)
- virtual 3D city models (2)
- virtuelle 3D-Stadtmodelle (2)
- visualization (2)
- 'Peer To Peer' (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 printing (1)
- 3D semiotics (1)
- 3D visualization (1)
- 3D-Stadtmodelle (1)
- 3d city models (1)
- ABRACADABRA (1)
- ADFS (1)
- ARCS Modell (1)
- Abbrecherquote (1)
- Abstraktion (1)
- Accepting Grammars (1)
- Achievement (1)
- Ackerschmalwand (1)
- Active Directory Federation Services (1)
- Active Evaluation (1)
- Activity Theory (1)
- Activity-orientated Learning (1)
- Adversarial Learning (1)
- Aktive Evaluierung (1)
- Akzeptierende Grammatiken (1)
- Algorithmenablaufplanung (1)
- Algorithmenkonfiguration (1)
- Algorithmenselektion (1)
- Alignment (1)
- Angewandte Spieltheorie (1)
- Anisotroper Kuwahara Filter (1)
- Anleitung (1)
- Antwortmengen Programmierung (1)
- Applied Game Theory (1)
- Arabidopsis thaliana (1)
- Arduino (1)
- Artificial Intelligence (1)
- Aspect-Oriented Programming (1)
- Aspektorientierte Programmierung (1)
- Asynchrone Schaltung (1)
- Audience Response Systeme (1)
- Aufzählung (1)
- Ausreissererkennung (1)
- Austria (1)
- Authentifizierung (1)
- Authorization (1)
- Autismus (1)
- Automated Theorem Proving (1)
- Autorisierung (1)
- BCH (1)
- BCI (1)
- BSS (1)
- Bachelorstudierende der Informatik (1)
- Baumweite (1)
- Behavior (1)
- Benutzeroberfläche (1)
- Berührungseingaben (1)
- Betrachtungsebenen (1)
- Beweistheorie (1)
- Bilddatenanalyse (1)
- Bildung (1)
- Binäres Entscheidungsdiagramm (1)
- Biocomputing (1)
- Bioelektrisches Signal (1)
- Bioinformatik (1)
- Blended Learning (1)
- Bloom’s Taxonomy (1)
- Boolean constraint solver (1)
- Brain Computer Interface (1)
- Business Process Models (1)
- CS concepts (1)
- CSC (1)
- Cactus (1)
- Capability approach (1)
- Challenges (1)
- Choreographien (1)
- CityGML (1)
- Classification (1)
- Clause Learning (1)
- Cloud Computing (1)
- Cloud computing (1)
- Clusteranalyse (1)
- Codierung (1)
- Cognitive Skills (1)
- Common Spatial Pattern (1)
- Competences (1)
- Competencies (1)
- Complementary Circuits (1)
- Compliance (1)
- Composition (1)
- Computational Complexity (1)
- Computational Thinking (1)
- Computer Science in Context (1)
- Computergestützes Training (1)
- Computing (1)
- Conceptual (1)
- Constraint (1)
- Constraint-Programmierung (1)
- Constructive solid geometry (1)
- Contest (1)
- Contextualisation (1)
- Contradictions (1)
- Controlled Derivations (1)
- Covariate Shift (1)
- Curriculum (1)
- Curriculum Development (1)
- DDoS (1)
- DNA (1)
- DNA computing (1)
- DNS (1)
- Data Analysis (1)
- Data Management (1)
- Databases (1)
- Datenschutz (1)
- Deep Learning (1)
- Defining characteristics of physical computing (1)
- Dempster-Shafer-Theorie (1)
- Dempster–Shafer theory (1)
- Description Logics (1)
- Deskriptive Logik (1)
- Diagonalisierung (1)
- Didaktik der Informatik (1)
- Didaktische Konzepte (1)
- Dienstkomposition (1)
- Dienstplattform (1)
- Differenz von Gauss Filtern (1)
- Digital Competence (1)
- Digital Education (1)
- Digital Game Based Learning (1)
- Digital Revolution (1)
- Distributed Computing (1)
- Diversität (1)
- Dreidimensionale Computergraphik (1)
- Dynamic Programming (1)
- Dynamic assessment (1)
- Dynamische Programmierung (1)
- Dynamische Rekonfiguration (1)
- Early Literacy (1)
- Echtzeitanwendung (1)
- Educational Standards (1)
- Educational software (1)
- Eingabegenauigkeit (1)
- Eisenbahnnetz (1)
- Elektroencephalographie (1)
- Embedded Systems (1)
- Emotionen (1)
- Emotionsforschung (1)
- Enterprise Search (1)
- Entscheidungsbäume (1)
- Entwurf (1)
- Entwurfsmuster (1)
- Entwurfsmuster für SOA-Sicherheit (1)
- Entwurfsraumexploration (1)
- Equilibrium logic (1)
- Erfüllbarkeit einer Formel der Aussagenlogik (1)
- Erfüllbarkeitsproblem (1)
- Error Estimation (1)
- Error-Detection Circuits (1)
- Euclid’s algorithm (1)
- European Bioinformatics Institute (1)
- Evidenztheorie (1)
- Exploration (1)
- Exponential Time Hypothesis (1)
- Exponentialzeit Hypothese (1)
- FMC-QE (1)
- FOSS (1)
- FPGA (1)
- Facebook (1)
- Feature Combination (1)
- Feedback (1)
- Fehlende Daten (1)
- Fehlererkennung (1)
- Fehlerkorrektur (1)
- Fehlerschätzung (1)
- Fehlvorstellung (1)
- Fibonacci numbers (1)
- Flussgesteuerter Bilateraler Filter (1)
- Focus+Context Visualization (1)
- Fokus-&-Kontext Visualisierung (1)
- Formeln der quantifizierten Aussagenlogik (1)
- Function (1)
- Fundamental Ideas (1)
- GPU (1)
- Game-based learning (1)
- Gebäudemodelle (1)
- Gehirn-Computer-Schnittstelle (1)
- Geländemodelle (1)
- Generalisierung (1)
- Geodaten (1)
- Geometrieerzeugung (1)
- Geovisualisierung (1)
- Geschäftsprozessmodelle (1)
- Gesichtsausdruck (1)
- Gesteuerte Ableitungen (1)
- Gleichheit (1)
- Globus (1)
- Grammar Systems (1)
- Grammatikalische Inferenz (1)
- Grammatiksysteme (1)
- Graph-basiertes Ranking (1)
- Graphensuche (1)
- Graphfärbung (1)
- Grid (1)
- Grid Computing (1)
- HDI (1)
- Hardware-Software-Co-Design (1)
- Hauptkomponentenanalyse (1)
- Heterogenität (1)
- High-Level Synthesis (1)
- Hochschullehre (1)
- Hochschulsystem (1)
- I/O-effiziente Algorithmen (1)
- ICT (1)
- ICT Competence (1)
- ICT competencies (1)
- ICT skills (1)
- IT security (1)
- IT-Security (1)
- IT-Sicherheit (1)
- Informatik-Studiengänge (1)
- Informatiksystem (1)
- Informatikunterricht (1)
- Informatikvoraussetzungen (1)
- Information Transfer Rate (1)
- Informationsextraktion (1)
- Infrastruktur (1)
- Inkonsistenz (1)
- Inquiry-based Learning (1)
- Integration (1)
- Interactive Rendering (1)
- Interactive system (1)
- Interaktionsmodel (1)
- Interaktionsmodellierung (1)
- Interaktionstechniken (1)
- Interaktives Rendering (1)
- Interaktives System (1)
- Interface design (1)
- Internet Security (1)
- Internet applications (1)
- Internet-Sicherheit (1)
- Internetanwendungen (1)
- Intuition (1)
- Java Security Framework (1)
- Kartografisches Design (1)
- Kern-PCA (1)
- Kernmethoden (1)
- Klassifikation (1)
- Klassifikator-Kalibrierung (1)
- Kommunikation (1)
- Kompetenz (1)
- Kompetenzerwerb (1)
- Komplexität (1)
- Komplexitätsbewältigung (1)
- Komplexitätstheorie (1)
- Komposition (1)
- Konnektionskalkül (1)
- Konzeptionell (1)
- Kryptographie (1)
- Kybernetik (1)
- LMS (1)
- Landmarken (1)
- Laser Cutten (1)
- Learners (1)
- Learning Fields (1)
- Learning ecology (1)
- Learning interfaces development (1)
- Learning with ICT (1)
- Lebenslanges Lernen (1)
- Leftmost Derivations (1)
- Lehrer (1)
- Lehrer*innenbildung (1)
- Leistungsfähigkeit (1)
- Leistungsvorhersage (1)
- Lern-App (1)
- Lernmotivation (1)
- Lernsoftware (1)
- Liguistisch (1)
- Linksableitungen (1)
- Logarithm (1)
- Logikkalkül (1)
- Logiksynthese (1)
- Lower Bounds (1)
- Lower Secondary Level (1)
- MEG (1)
- MOOCs (1)
- Magnetoencephalographie (1)
- Malware (1)
- Massive Open Online Courses (1)
- Matrizen-Eigenwertaufgabe (1)
- Measurement (1)
- Megamodel (1)
- Megamodell (1)
- Mehrklassen-Klassifikation (1)
- Metamodell (1)
- Middleware (1)
- Migration (1)
- Mischmodelle (1)
- Mischung <Signalverarbeitung> (1)
- Mobiles Lernen (1)
- Mobilgeräte (1)
- Model Based Engineering (1)
- Model Checking (1)
- Model Driven Architecture (1)
- Model Management (1)
- Model-Driven Engineering (1)
- Modeling (1)
- Modell Management (1)
- Modell-driven Security (1)
- Modell-getriebene Sicherheit (1)
- Modellbasiert (1)
- Modellgetriebene Architektur (1)
- Modellgetriebene Entwicklung (1)
- Molekulare Bioinformatik (1)
- Multi Task Learning (1)
- Multi-Class (1)
- Multi-Task-Lernen (1)
- Multiprocessor (1)
- Multiprozessor (1)
- Music Technology (1)
- NUI (1)
- Natural Science Education (1)
- Navigation (1)
- Netzwerk (1)
- Netzwerke (1)
- Neuronales Netz (1)
- New On-Line Error-Detection Methode (1)
- Next Generation Network (1)
- Nicht-photorealistisches Rendering (1)
- Nichtfotorealistische Bildsynthese (1)
- NoSQL (1)
- Norway (1)
- Novice programmers (1)
- Nutzungsinteresse (1)
- Objektive Schwierigkeit (1)
- Omega (1)
- Onlinelehre (1)
- Ontologies (1)
- Ontology (1)
- Open Source (1)
- OpenOLAT (1)
- Optimierungsproblem (1)
- Owner-Retained Access Control (ORAC) (1)
- Parallel Programming (1)
- Parallele Datenverarbeitung (1)
- Paralleles Rechnen (1)
- Parallelrechner (1)
- Parameterized Complexity (1)
- Parametrisierte Komplexität (1)
- Parsing (1)
- Patterns (1)
- Pedagogical content knowledge (1)
- Peer-to-Peer-Netz ; GRID computing ; Zuverlässigkeit ; Web Services ; Betriebsmittelverwaltung ; Migration (1)
- Performance (1)
- Performance Prediction (1)
- Physical Science (1)
- Platzierung (1)
- Policy Enforcement (1)
- Policy Languages (1)
- Policy Sprachen (1)
- Pre-RS Traceability (1)
- Prediction Game (1)
- Predictive Models (1)
- Preprocessing (1)
- Problem Solving (1)
- Probleme in der Studie (1)
- Problemlösen (1)
- Process (1)
- Process modeling (1)
- Professoren (1)
- Programmierung (1)
- Proof Theory (1)
- Prozess (1)
- Prozess Verbesserung (1)
- Prozesse (1)
- Prozessmodell (1)
- Prädiktionsspiel (1)
- Präferenzen (1)
- Quantenkryptographie (1)
- Quantified Boolean Formula (QBF) (1)
- Quantitative Modeling (1)
- Quantitative Modellierung (1)
- Queuing Theory (1)
- Recommendations for CS-Curricula in Higher Education (1)
- Reconfigurable (1)
- Rekonfiguration (1)
- Rendering (1)
- Reparatur (1)
- SOA Security Pattern (1)
- SSO (1)
- STG decomposition (1)
- STG-Dekomposition (1)
- Sample Selection Bias (1)
- Satisfiability (1)
- Scalability (1)
- Scene graph systems (1)
- Schlüsselkompetenzen (1)
- Security Modelling (1)
- Segmentierung (1)
- Selektion (1)
- Selektionsbias (1)
- Self-Checking Circuits (1)
- Semantic Search (1)
- Semantik Web (1)
- Semantische Suche (1)
- Sensors (1)
- Service Creation (1)
- Service Delivery Platform (1)
- Service convergence (1)
- Service-Orientierte Architekturen (1)
- Service-oriented Architectures (1)
- Shader (1)
- Sicherheitsmodellierung (1)
- Signal Processing (1)
- Signalquellentrennung (1)
- Signaltrennung (1)
- Simultane Diagonalisierung (1)
- Single Sign On (1)
- Single Trial Analysis (1)
- Skalierbarkeit (1)
- Skelettberechnung (1)
- Small Private Online Courses (1)
- Social (1)
- Software (1)
- Software Engineering (1)
- Software architecture (1)
- Softwarearchitektur (1)
- Softwareentwicklung (1)
- Spam (1)
- Spam Filtering (1)
- Spam-Erkennung (1)
- Spam-Filter (1)
- Spam-Filtering (1)
- Spatio-Spectral Filter (1)
- Spawning (1)
- Sprachdesign (1)
- Statistical Tests (1)
- Statistikprogramm R (1)
- Statistische Tests (1)
- Stilisierung (1)
- Strategie (1)
- Structuring (1)
- Strukturierung (1)
- Studentenerwartungen (1)
- Studentenhaltungen (1)
- Studentenjobs (1)
- Studienabbrecher (1)
- Studiendauer (1)
- Suche (1)
- Synthese (1)
- System Biologie (1)
- System structure (1)
- Systembiologie (1)
- Systementwurf (1)
- Szenengraph (1)
- TPTP (1)
- Tasks (1)
- Teacher perceptions (1)
- Teachers (1)
- Teaching information security (1)
- Technology proficiency (1)
- Telekommunikation (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 (1)
- Time Augmented Petri Nets (1)
- Tool (1)
- Traceability (1)
- Tracking (1)
- Transformation (1)
- Treewidth (1)
- Unabhängige Komponentenanalyse (1)
- Universität Bagdad (1)
- Universität Potsdam (1)
- Universitätseinstellungen (1)
- Untere Schranken (1)
- Unvollständigkeit (1)
- Usage Interest (1)
- User Experience (1)
- VM (1)
- Verhalten (1)
- Verifikation (1)
- Verletzung Auflösung (1)
- Verletzung Erklärung (1)
- Verteiltes Rechnen (1)
- Verteilungsunterschied (1)
- Violation Explanation (1)
- Violation Resolution (1)
- Virtual Reality (1)
- Virtuelles 3D Stadtmodell (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)
- Webseite (1)
- Weiterbildung (1)
- Well-structuredness (1)
- Wirtschaftsinformatik (1)
- Wissensrepräsentation und -verarbeitung (1)
- Wissensrepräsentation und Schlussfolgerung (1)
- Wohlstrukturiertheit (1)
- Workflow (1)
- Young People (1)
- ZQSA (1)
- ZQSAT (1)
- Zeitbehaftete Petri Netze (1)
- Zero-Suppressed Binary Decision Diagram (ZDD) (1)
- Zuverlässigkeitsanalyse (1)
- adaptiv (1)
- adaptive (1)
- algorithm configuration (1)
- algorithm scheduling (1)
- algorithm selection (1)
- analogical thinking (1)
- animated PCA (1)
- animierte PCA (1)
- anisotropic Kuwahara filter (1)
- approximate joint diagonalization (1)
- argument mining (1)
- argumentation structure (1)
- arithmethische Prozeduren (1)
- arithmetic procedures (1)
- arousal perception (1)
- artificial intelligence (1)
- assistive Technologien (1)
- assistive technologies (1)
- asynchronous circuit (1)
- authentication (1)
- automated theorem proving (1)
- automatic theorem prover (1)
- automatisierter Theorembeweiser (1)
- bild (1)
- binary representation (1)
- binary search (1)
- bio-computing (1)
- blind source separation (1)
- building models (1)
- business informatics (1)
- cartographic design (1)
- changing the study field (1)
- changing the university (1)
- choreographies (1)
- classifier calibration (1)
- classroom language (1)
- clause learning (1)
- clustering (1)
- cognitive modifiability (1)
- coherence-enhancing filtering (1)
- communication (1)
- competence (1)
- competencies (1)
- competency (1)
- comprehension (1)
- computational biology (1)
- computational methods (1)
- computer science teachers (1)
- computer security (1)
- computergestützte Methoden (1)
- connection calculus (1)
- constraint (1)
- constraint programming (1)
- cryptography (1)
- cs4fn (1)
- curriculum theory (1)
- decision trees (1)
- design (1)
- design space exploration (1)
- didaktisches Konzept (1)
- difference of Gaussians (1)
- digitale Bildung (1)
- digitale Hochschullehre (1)
- digitally-enabled pedagogies (1)
- divide and conquer (1)
- dropout (1)
- dynamic (1)
- dynamic classification (1)
- dynamic reconfiguration (1)
- dynamisch (1)
- dynamische Klassifikation (1)
- e-Learning (1)
- e-mentoring (1)
- education and public policy (1)
- educational programming (1)
- educational systems (1)
- edutainment (1)
- email spam detection (1)
- emotion (1)
- emotion representation (1)
- emotion research (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)
- evidence theory (1)
- explicit negation (1)
- exponentiation (1)
- external memory algorithms (1)
- face tracking (1)
- facial expression (1)
- flow-based bilateral filter (1)
- freie Daten (1)
- freie Software (1)
- fun (1)
- generalization (1)
- geometry generation (1)
- geospatial data (1)
- geovisualization (1)
- global constraints (1)
- globale Constraints (1)
- grammar inference (1)
- graph clustering (1)
- graph-based ranking (1)
- graph-search (1)
- hardware-software-codesign (1)
- high school (1)
- higher (1)
- image (1)
- image data analysis (1)
- incompleteness (1)
- inconsistency (1)
- independent component analysis (1)
- informal and formal learning (1)
- informatics education (1)
- information extraction (1)
- infrastructure (1)
- innovation (1)
- input accuracy (1)
- interaction modeling (1)
- interaction techniques (1)
- interactive course (1)
- interactive workshop (1)
- intuition (1)
- kernel PCA (1)
- kernel methods (1)
- key competences in physical computing (1)
- key competencies (1)
- kinaesthetic teaching (1)
- klinisch-praktischer Unterricht (1)
- konvergente Dienste (1)
- landmarks (1)
- language design (1)
- leanCoP (1)
- learning (1)
- linear code (1)
- linearer Code (1)
- linguistic (1)
- logic programming (1)
- logic synthesis (1)
- logical calculus (1)
- logical signaling networks (1)
- logische Ergänzung (1)
- logische Programmierung (1)
- logische Signalnetzwerke (1)
- malware detection (1)
- map/reduce (1)
- maschinelles Lernen (1)
- maschninelles Lernen (1)
- mediated learning experience (1)
- medical (1)
- medizinisch (1)
- meta model (1)
- misconception (1)
- mixture models (1)
- mobile devices (1)
- mobile learning (1)
- mobile technologies and apps (1)
- mobiles Lernen (1)
- model-based (1)
- model-driven architecture (1)
- molecular networks (1)
- molekulare Netzwerke (1)
- multi core data processing (1)
- multi-class classification (1)
- multiuser (1)
- navigation (1)
- network (1)
- networks (1)
- networks-on-chip (1)
- neue Online-Fehlererkennungsmethode (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)
- objective difficulty (1)
- omega (1)
- on-chip (1)
- online assistance (1)
- open learning (1)
- open source (1)
- operating system (1)
- organisational evolution (1)
- outlier detection (1)
- overcomplete ICA (1)
- paper prototyping (1)
- parallel solving (1)
- paralleles Lösen (1)
- parameter (1)
- parsing (1)
- pattern recognition (1)
- pedagogy (1)
- perception (1)
- perception differences (1)
- personal (1)
- personal response systems (1)
- philosophical foundation of informatics pedagogy (1)
- physical computing tools (1)
- placement (1)
- policy evaluation (1)
- pre-primary level (1)
- prediction (1)
- preferences (1)
- preprocessing (1)
- primary education (1)
- primary level (1)
- priorities (1)
- problem-solving (1)
- process (1)
- process improvement (1)
- process model (1)
- process modelling (1)
- professional development (1)
- professors (1)
- programming (1)
- programming in context (1)
- proving (1)
- quantum cryptography (1)
- railway network (1)
- real-time application (1)
- reconfiguration (1)
- rekonfigurierbar (1)
- reliability assessment (1)
- repair (1)
- robust ICA (1)
- robuste ICA (1)
- scheduling (1)
- search (1)
- secondary computer science education (1)
- secondary education (1)
- segmentation (1)
- selbstprüfende Schaltungen (1)
- selection (1)
- self-efficacy (1)
- semantisches Netz (1)
- shader (1)
- sign language (1)
- skeletonization (1)
- social media (1)
- software (1)
- software development (1)
- software engineering (1)
- speed independence (1)
- statistics program R (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)
- teacher competencies (1)
- teacher training (1)
- teachers (1)
- teaching informatics in general education (1)
- technische Rahmenbedingungen (1)
- temporary binding (1)
- terrain models (1)
- test (1)
- tools (1)
- topics (1)
- touch input (1)
- tptp (1)
- tracing (1)
- transformation (1)
- tutorial section (1)
- unification (1)
- user interfaces (1)
- user-centred (1)
- verification (1)
- virtual 3D city model (1)
- virtual machine (1)
- virtual mobility (1)
- virtual reality (1)
- überbestimmte ICA (1)
- ‘unplugged’ computing (1)
Institute
- Institut für Informatik und Computational Science (207) (remove)
In a recent line of research, two familiar concepts from logic programming semantics (unfounded sets and splitting) were extrapolated to the case of epistemic logic programs. The property of epistemic splitting provides a natural and modular way to understand programs without epistemic cycles but, surprisingly, was only fulfilled by Gelfond's original semantics (G91), among the many proposals in the literature. On the other hand, G91 may suffer from a kind of self-supported, unfounded derivations when epistemic cycles come into play. Recently, the absence of these derivations was also formalised as a property of epistemic semantics called foundedness. Moreover, a first semantics proved to satisfy foundedness was also proposed, the so-called Founded Autoepistemic Equilibrium Logic (FAEEL). In this paper, we prove that FAEEL also satisfies the epistemic splitting property something that, together with foundedness, was not fulfilled by any other approach up to date. To prove this result, we provide an alternative characterisation of FAEEL as a combination of G91 with a simpler logic we called Founded Epistemic Equilibrium Logic (FEEL), which is somehow an extrapolation of the stable model semantics to the modal logic S5.
Parsing of argumentative structures has become a very active line of research in recent years. Like discourse parsing or any other natural language task that requires prediction of linguistic structures, most approaches choose to learn a local model and then perform global decoding over the local probability distributions, often imposing constraints that are specific to the task at hand. Specifically for argumentation parsing, two decoding approaches have been recently proposed: Minimum Spanning Trees (MST) and Integer Linear Programming (ILP), following similar trends in discourse parsing. In contrast to discourse parsing though, where trees are not always used as underlying annotation schemes, argumentation structures so far have always been represented with trees. Using the 'argumentative microtext corpus' [in: Argumentation and Reasoned Action: Proceedings of the 1st European Conference on Argumentation, Lisbon 2015 / Vol. 2, College Publications, London, 2016, pp. 801-815] as underlying data and replicating three different decoding mechanisms, in this paper we propose a novel ILP decoder and an extension to our earlier MST work, and then thoroughly compare the approaches. The result is that our new decoder outperforms related work in important respects, and that in general, ILP and MST yield very similar performance.
Emotions are a central element of human experience. They occur with high frequency in everyday life and play an important role in decision making. However, currently there is no consensus among researchers on what constitutes an emotion and on how emotions should be investigated. This dissertation identifies three problems of current emotion research: the problem of ground truth, the problem of incomplete constructs and the problem of optimal representation. I argue for a focus on the detailed measurement of emotion manifestations with computer-aided methods to solve these problems. This approach is demonstrated in three research projects, which describe the development of methods specific to these problems as well as their application to concrete research questions.
The problem of ground truth describes the practice to presuppose a certain structure of emotions as the a priori ground truth. This determines the range of emotion descriptions and sets a standard for the correct assignment of these descriptions. The first project illustrates how this problem can be circumvented with a multidimensional emotion perception paradigm which stands in contrast to the emotion recognition paradigm typically employed in emotion research. This paradigm allows to calculate an objective difficulty measure and to collect subjective difficulty ratings for the perception of emotional stimuli. Moreover, it enables the use of an arbitrary number of emotion stimuli categories as compared to the commonly used six basic emotion categories. Accordingly, we collected data from 441 participants using dynamic facial expression stimuli from 40 emotion categories. Our findings suggest an increase in emotion perception difficulty with increasing actor age and provide evidence to suggest that young adults, the elderly and men underestimate their emotion perception difficulty. While these effects were predicted from the literature, we also found unexpected and novel results. In particular, the increased difficulty on the objective difficulty measure for female actors and observers stood in contrast to reported findings. Exploratory analyses revealed low relevance of person-specific variables for the prediction of emotion perception difficulty, but highlighted the importance of a general pleasure dimension for the ease of emotion perception.
The second project targets the problem of incomplete constructs which relates to vaguely defined psychological constructs on emotion with insufficient ties to tangible manifestations. The project exemplifies how a modern data collection method such as face tracking data can be used to sharpen these constructs on the example of arousal, a long-standing but fuzzy construct in emotion research. It describes how measures of distance, speed and magnitude of acceleration can be computed from face tracking data and investigates their intercorrelations. We find moderate to strong correlations among all measures of static information on one hand and all measures of dynamic information on the other. The project then investigates how self-rated arousal is tied to these measures in 401 neurotypical individuals and 19 individuals with autism. Distance to the neutral face was predictive of arousal ratings in both groups. Lower mean arousal ratings were found for the autistic group, but no difference in correlation of the measures and arousal ratings could be found between groups. Results were replicated in a high autistic traits group consisting of 41 participants. The findings suggest a qualitatively similar perception of arousal for individuals with and without autism. No correlations between valence ratings and any of the measures could be found which emphasizes the specificity of our tested measures for the construct of arousal.
The problem of optimal representation refers to the search for the best representation of emotions and the assumption that there is a one-fits-all solution. In the third project we introduce partial least squares analysis as a general method to find an optimal representation to relate two high-dimensional data sets to each other. The project demonstrates its applicability to emotion research on the question of emotion perception differences between men and women. The method was used with emotion rating data from 441 participants and face tracking data computed on 306 videos. We found quantitative as well as qualitative differences in the perception of emotional facial expressions between these groups. We showed that women’s emotional perception systematically captured more of the variance in facial expressions. Additionally, we could show that significant differences exist in the way that women and men perceive some facial expressions which could be visualized as concrete facial expression sequences. These expressions suggest differing perceptions of masked and ambiguous facial expressions between the sexes. In order to facilitate use of the developed method by the research community, a package for the statistical environment R was written. Furthermore, to call attention to the method and its usefulness for emotion research, a website was designed that allows users to explore a model of emotion ratings and facial expression data in an interactive fashion.
Einsatz einer mobilen Lern-App - Ein Werkzeug zur Verbesserung von klinisch-praktischem Unterricht
(2018)
Der Unterricht am Krankenbett ist im Medizinstudium eine wertvolle Möglichkeit klinisch-praktische Fertigkeiten zu erlernen. Eine optimale Vorbereitung der Studierenden ist dabei Voraussetzung. Eine mobile Lern-App wurde entwickelt, die den Studierenden, neben Lernzielen, Kursinhalte und Anleitungen zu Untersuchungstechniken bietet, um die Vorbereitung auf einen klinisch-praktischen Kurs zu fördern und Kurzinformationen auch während des Kurses zur Verfügung zu stellen. 175 Studierende hatten die Möglichkeit die App parallel zu einem klinischen Untersuchungs-Kurs im Semester zu nutzen. Im Anschluss beantworteten die Studierenden einen Fragebogen zur Nützlichkeit und Vielseitigkeit der App und zur Zufriedenheit mit der App unter Verwendung eine 5-Punkt-Likert-Skala und zwei offenen Fragen. In diesem Beitrag wird das Kurskonzept zusammen mit der Lern-App, die Ergebnisse aus dem Fragebogen und unsere Schlussfolgerungen daraus vorgestellt. Studierende bewerteten die App grundsätzlich als hilfreich. Sie sollte dabei gründlich eingeführt werden. Patienten sollten über die Nutzung von Smartphones im Studentenunterricht zu Lernzwecken informiert werden.
Das Training sozioemotionaler Kompetenzen ist gerade für Menschen mit Autismus nützlich. Ein solches Training kann mithilfe einer spielbasierten Anwendung effektiv gestaltet werden. Zwei Minispiele, Mimikry und Emo-Mahjong, wurden realisiert und hinsichtlich User Experience evaluiert. Die jeweiligen Konzepte und die Evaluationsergebnisse sollen hier vorgestellt werden.
Die Veröffentlichung eines global frei verfügbaren Onlinekurses abseits der großen MOOC Plattformen bringt spezielle Herausforderungen mit sich. Neben technischen Herausforderungen sind eine effiziente Wissensvermittlung und die Erhaltung der Lernmotivation zentral. Der folgende Beitrag stellt Techniken zur Steigerung der Lerneffizienz und -motivation anhand des ARCS Modells vor. Er zeigt auf, wie die verschiedenen Techniken in der Entwicklung des Onlinekurses „Designing Sustainable Food Systems“ umgesetzt wurden und inwieweit sie erfolgreich waren.
Berufsbegleitende Studiengänge stehen vor besonderen Schwierigkeiten, für die der Einsatz von Blended Learning-Szenarien sinnvoll sein kann. Welche speziellen Herausforderungen sich dabei ergeben und welche Lösungsansätze dagegen steuern, betrachtet der folgende Artikel anhand eines Praxisberichts aus dem Studiengang M. P. A. Wissenschaftsmanagement an der Universität Speyer.
Der vorliegende Beitrag berichtet auf der Grundlage von Erfahrungen mit dem Audience Response System (ARS) „Auditorium Mobile Classroom Service“ von Erfolgsfaktoren für den Einsatz in der universitären Lehre. Dabei werden sowohl die technischen Rahmenbedingungen und Herausforderungen der Anwendungen berücksichtigt, als auch die unterschiedlichen didaktischen Konzepte und Ziele der beteiligten Akteure (Studierende, Lehrende und Institution). Ziel ist es, Einflussfaktoren für den erfolgreichen Einsatz sowohl für die Praxis als auch die wissenschaftliche Untersuchung und Weiterentwicklung der Systeme zu benennen und ein heuristisches Framework für Chancen und Herausforderungen beim Einsatz von ARS anzubieten.
Der Beitrag skizziert ein Modell, das die Entwicklung digitaler Kompetenzen im Lehramtsstudium fördern soll. Zwar wird das Kompetenzmodell aus der Deutschdidaktik heraus entwickelt, nimmt aber auch fachübergreifende Anforderungen in den Bereichen Informationskompetenz, medientechnischer Kompetenzen, Fähigkeiten der Medienanalyse und -reflexion sowie Sprachhandlungskompetenz in den Blick. Damit wird das Ziel verfolgt, die besonderen Anforderungen angehender Lehrkräfte als Mediator*innen digitaler Kompetenzen darzustellen. Das beschriebene Modell dieser Vermittlungskompetenz dient der Verankerung digitaler Lehr-Lernkonzepte als wesentlicher Bestandteil der modernen Lehrer*innenbildung.
E-Learning Symposium 2018
(2018)
In den vergangenen Jahren sind viele E-Learning-Innovationen entstanden. Einige davon wurden auf den vergangenen E-Learning Symposien der Universität Potsdam präsentiert: Das erste E-Learning Symposium im Jahr 2012 konzentrierte sich auf unterschiedliche Möglichkeiten der Studierendenaktivierung und Lehrgestaltung. Das Symposium 2014 rückte vor allem die Studierenden ins Zentrum der Aufmerksamkeit. Im Jahr 2016 kam es durch das Zusammengehen des Symposiums mit der DeLFI-Tagung zu einer Fokussierung auf technische Innovationen. Doch was ist aus den Leuchttürmen von gestern geworden, und brauchen wir überhaupt noch neue Leuchttürme? Das Symposium setzt sich in diesem Jahr unter dem Motto „Innovation und Nachhaltigkeit – (k)ein Gegensatz?“ mit mediengestützten Lehr- und Lernprozessen im universitären Kontext auseinander und reflektiert aktuelle technische sowie didaktische Entwicklungen mit Blick auf deren mittel- bis langfristigen Einsatz in der Praxis.
Dieser Tagungsband zum E-Learning Symposium 2018 an der Universität Potsdam beinhaltet eine Mischung von Forschungs- und Praxisbeiträgen aus verschiedenen Fachdisziplinen und eröffnet vielschichtige Perspektiven auf das Thema E-Learning. Dabei werden die Vielfalt der didaktischen Einsatzszenarien als auch die Potentiale von Werk-zeugen und Methoden der Informatik in ihrem Zusammenspiel beleuchtet.
In seiner Keynote widmet sich Reinhard Keil dem Motto des Symposiums und geht der Nachhaltigkeit bei E-Learning-Projekten auf den Grund. Dabei analysiert und beleuchtet er anhand seiner über 15-jährigen Forschungspraxis die wichtigsten Wirkfaktoren und formuliert Empfehlungen zur Konzeption von E-Learning-Projekten. Im Gegensatz zu rein auf Kostenersparnis ausgerichteten (hochschul-)politischen Forderungen proklamiert er den Ansatz der hypothesengeleiteten Technikgestaltung, in der Nachhaltigkeit als Leitfrage oder Forschungsstrategie verstanden werden kann. In eine ähnliche Richtung geht der Beitrag von Iris Braun et al., die über Erfolgsfaktoren beim Einsatz von Audience Response Systemen in der universitären Lehre berichten.
Ein weiteres aktuelles Thema, sowohl für die Bildungstechnologie als auch in den Bildungswissenschaften allgemein, ist die Kompetenzorientierung und –modellierung. Hier geht es darum (Problemlöse-)Fähigkeiten gezielt zu beschreiben und in den Mittelpunkt der Lehre zu stellen. Johannes Konert stellt in einem eingeladenen Vortrag zwei Projekte vor, die den Prozess beginnend bei der Definition von Kompetenzen, deren Modellierung in einem semantischen maschinenlesbaren Format bis hin zur Erarbeitung von Methoden zur Kompetenzmessung und der elektronischen Zertifizierung aufzeigen. Dabei geht er auf technische Möglichkeiten, aber auch Grenzen ein. Auf einer spezifischeren Ebene beschäftigt sich Sarah Stumpf mit digitalen bzw. mediendidaktischen Kompetenzen im Lehramtsstudium und stellt ein Framework für die Förderung ebensolcher Kompetenzen bei angehenden Lehrkräften vor.
Der Einsatz von E-Learning birgt noch einige Herausforderungen. Dabei geht es oft um die Verbindung von Didaktik und Technik, den Erhalt von Aufmerksamkeit oder den Aufwand für das Erstellen von interaktiven Lehr- und Lerninhalten. Drei Beiträge in diesem Tagungsband beschäftigen sich mit dieser Thematik in unterschiedlichen Kontexten und zeigen Best-Practices und Lösungsansätze auf: Der Beitrag von Martina Wahl und Michael Hölscher behandelt den besonderen Kontext von Blended Learning-Szenarien in berufsbegleitenden Studiengängen. Um die Veröffentlichung eines global frei verfügbaren Onlinekurses abseits der großen MOOC Plattformen und den didaktischen Herausforderungen auch hinsichtlich der Motivation geht es im Beitrag von Ennio Marani und Isabel Jaisli. Schließlich schlagen Gregor Damnik et al. die automatische Erzeugung von Aufgaben zur Erhöhung von Interaktivität und Adaptivität in digitalen Lernressourcen vor, um den teilweise erheblichen Erstellungsaufwand zu reduzieren.
Zum Thema E-Learning zählen auch immer mobile Apps bzw. Spiele. Gleich zwei Beiträge beschäftigen sich mit dem Einsatz von E-Learning-Tools im Gesundheitskontext: Anna Tscherejkina und Anna Morgiel stellen in ihrem Beitrag Minispiele zum Training von sozio-emotionalen Kompetenzen für Menschen mit Autismus vor, und Stephanie Herbstreit et al. berichten vom Einsatz einer mobilen Lern-App zur Verbesserung von klinisch-praktischem Unterricht.
Die 8. Fachtagung für Hochschuldidaktik der Informatik (HDI) fand im September 2018 zusammen mit der Deutschen E-Learning Fachtagung Informatik (DeLFI) unter dem gemeinsamen Motto „Digitalisierungswahnsinn? - Wege der Bildungstransformationen“ in Frankfurt statt.
Dabei widmet sich die HDI allen Fragen der informatischen Bildung im Hochschulbereich. Schwerpunkte bildeten in diesem Jahr u. a.:
- Analyse der Inhalte und anzustrebenden Kompetenzen in Informatikveranstaltungen
- Programmieren lernen & Einstieg in Softwareentwicklung
- Spezialthemen: Data Science, Theoretische Informatik und Wissenschaftliches Arbeiten
Die Fachtagung widmet sich ausgewählten Fragestellungen dieser Themenkomplexe, die durch Vorträge ausgewiesener Experten und durch eingereichte Beiträge intensiv behandelt werden.
Dieses Lehrvideo zeigt aus der Perspektive einer Übertischkamera den fiktiven informatischen Hochleister Tom bei der Bearbeitung eines schwierigen Färbeproblems. Dabei kann man die fortlaufend von ihm angefertigten Skizzen beobachten und seine Gedankengänge genau verfolgen. Denn dieser Problemlöser arbeitet unter lautem Denken, d. h. er spricht alle seine Gedankengänge laut aus. Man kann zuschauen, wie Tom zunächst die Aufgabe analysiert und die dadurch gewonnenen Erkenntnisse in der anschließenden Problembearbeitung gewinnbringend einsetzt. Der Zuschauer wird dabei aber nicht allein gelassen. An markanten Stellen wird das Video unterbrochen und Toms zurückliegende Aktivitäten mit animierten Bildsequenzen vertiefend erläutert. Schwache Problemlöser können so die in Unterricht oder Vorlesung vermittelten Kenntnisse über informatische Problemlösemethoden vertiefen und deren Anwendung durch einen starken Problemlöser beispielhaft miterleben. Entstanden ist dieses Video aus einer Vergleichsstudie mit starken und schwachen Problemlösern. Die effizienten Methoden der Hochleister wurden didaktisch aufgearbeitet und zu einem modellhaften Problemlöseprozess zusammengesetzt. Der wissenschaftliche Hintergrund des Lehrvideos wird durch eine als Bildergeschichte erzählte Rahmenhandlung verdeutlicht. Bei Erstsemesterstudenten der Informatik, denen dieses Video zur Bewertung vorgespielt wurde, fand dieses Konzept große Zustimmung. Tenor: Unterhaltsam und lehrreich zugleich.
Services that operate over the Internet are under constant threat of being exposed to fraudulent use. Maintaining good user experience for legitimate users often requires the classification of entities as malicious or legitimate in order to initiate countermeasures. As an example, inbound email spam filters decide for spam or non-spam. They can base their decision on both the content of each email as well as on features that summarize prior emails received from the sending server. In general, discriminative classification methods learn to distinguish positive from negative entities. Each decision for a label may be based on features of the entity and related entities. When labels of related entities have strong interdependencies---as can be assumed e.g. for emails being delivered by the same user---classification decisions should not be made independently and dependencies should be modeled in the decision function. This thesis addresses the formulation of discriminative classification problems that are tailored for the specific demands of the following three Internet security applications. Theoretical and algorithmic solutions are devised to protect an email service against flooding of user inboxes, to mitigate abusive usage of outbound email servers, and to protect web servers against distributed denial of service attacks.
In the application of filtering an inbound email stream for unsolicited emails, utilizing features that go beyond each individual email's content can be valuable. Information about each sending mail server can be aggregated over time and may help in identifying unwanted emails. However, while this information will be available to the deployed email filter, some parts of the training data that are compiled by third party providers may not contain this information. The missing features have to be estimated at training time in order to learn a classification model. In this thesis an algorithm is derived that learns a decision function that integrates over a distribution of values for each missing entry. The distribution of missing values is a free parameter that is optimized to learn an optimal decision function.
The outbound stream of emails of an email service provider can be separated by the customer IDs that ask for delivery. All emails that are sent by the same ID in the same period of time are related, both in content and in label. Hijacked customer accounts may send batches of unsolicited emails to other email providers, which in turn might blacklist the sender's email servers after detection of incoming spam emails. The risk of being blocked from further delivery depends on the rate of outgoing unwanted emails and the duration of high spam sending rates. An optimization problem is developed that minimizes the expected cost for the email provider by learning a decision function that assigns a limit on the sending rate to customers based on the each customer's email stream.
Identifying attacking IPs during HTTP-level DDoS attacks allows to block those IPs from further accessing the web servers. DDoS attacks are usually carried out by infected clients that are members of the same botnet and show similar traffic patterns. HTTP-level attacks aim at exhausting one or more resources of the web server infrastructure, such as CPU time. If the joint set of attackers cannot increase resource usage close to the maximum capacity, no effect will be experienced by legitimate users of hosted web sites. However, if the additional load raises the computational burden towards the critical range, user experience will degrade until service may be unavailable altogether. As the loss of missing one attacker depends on block decisions for other attackers---if most other attackers are detected, not blocking one client will likely not be harmful---a structured output model has to be learned. In this thesis an algorithm is developed that learns a structured prediction decoder that searches the space of label assignments, guided by a policy.
Each model is evaluated on real-world data and is compared to reference methods. The results show that modeling each classification problem according to the specific demands of the task improves performance over solutions that do not consider the constraints inherent to an application.
Personal fabrication tools, such as 3D printers, are on the way of enabling a future in which non-technical users will be able to create custom objects. However, while the hardware is there, the current interaction model behind existing design tools is not suitable for non-technical users. Today, 3D printers are operated by fabricating the object in one go, which tends to take overnight due to the slow 3D printing technology. Consequently, the current interaction model requires users to think carefully before printing as every mistake may imply another overnight print. Planning every step ahead, however, is not feasible for non-technical users as they lack the experience to reason about the consequences of their design decisions.
In this dissertation, we propose changing the interaction model around personal fabrication tools to better serve this user group. We draw inspiration from personal computing and argue that the evolution of personal fabrication may resemble the evolution of personal computing: Computing started with machines that executed a program in one go before returning the result to the user. By decreasing the interaction unit to single requests, turn-taking systems such as the command line evolved, which provided users with feedback after every input. Finally, with the introduction of direct-manipulation interfaces, users continuously interacted with a program receiving feedback about every action in real-time. In this dissertation, we explore whether these interaction concepts can be applied to personal fabrication as well.
We start with fabricating an object in one go and investigate how to tighten the feedback-cycle on an object-level: We contribute a method called low-fidelity fabrication, which saves up to 90% fabrication time by creating objects as fast low-fidelity previews, which are sufficient to evaluate key design aspects. Depending on what is currently being tested, we propose different conversions that enable users to focus on different parts: faBrickator allows for a modular design in the early stages of prototyping; when users move on WirePrint allows quickly testing an object's shape, while Platener allows testing an object's technical function. We present an interactive editor for each technique and explain the underlying conversion algorithms.
By interacting on smaller units, such as a single element of an object, we explore what it means to transition from systems that fabricate objects in one go to turn-taking systems. We start with a 2D system called constructable: Users draw with a laser pointer onto the workpiece inside a laser cutter. The drawing is captured with an overhead camera. As soon as the the user finishes drawing an element, such as a line, the constructable system beautifies the path and cuts it--resulting in physical output after every editing step. We extend constructable towards 3D editing by developing a novel laser-cutting technique for 3D objects called LaserOrigami that works by heating up the workpiece with the defocused laser until the material becomes compliant and bends down under gravity. While constructable and LaserOrigami allow for fast physical feedback, the interaction is still best described as turn-taking since it consists of two discrete steps: users first create an input and afterwards the system provides physical output.
By decreasing the interaction unit even further to a single feature, we can achieve real-time physical feedback: Input by the user and output by the fabrication device are so tightly coupled that no visible lag exists. This allows us to explore what it means to transition from turn-taking interfaces, which only allow exploring one option at a time, to direct manipulation interfaces with real-time physical feedback, which allow users to explore the entire space of options continuously with a single interaction. We present a system called FormFab, which allows for such direct control. FormFab is based on the same principle as LaserOrigami: It uses a workpiece that when warmed up becomes compliant and can be reshaped. However, FormFab achieves the reshaping not based on gravity, but through a pneumatic system that users can control interactively. As users interact, they see the shape change in real-time.
We conclude this dissertation by extrapolating the current evolution into a future in which large numbers of people use the new technology to create objects. We see two additional challenges on the horizon: sustainability and intellectual property. We investigate sustainability by demonstrating how to print less and instead patch physical objects. We explore questions around intellectual property with a system called Scotty that transfers objects without creating duplicates, thereby preserving the designer's copyright.
Computer Security deals with the detection and mitigation of threats to computer networks, data, and computing hardware. This
thesis addresses the following two computer security problems: email spam campaign and malware detection.
Email spam campaigns can easily be generated using popular dissemination tools by specifying simple grammars that serve as message templates. A grammar is disseminated to nodes of a bot net, the nodes create messages by instantiating the grammar at random. Email spam campaigns can encompass huge data volumes and therefore pose a threat to the stability of the infrastructure of email service providers that have to store them. Malware -software that serves a malicious purpose- is affecting web servers, client computers via active content, and client computers through executable files. Without the help of malware detection systems it would be easy for malware creators to collect sensitive information or to infiltrate computers.
The detection of threats -such as email-spam messages, phishing messages, or malware- is an adversarial and therefore intrinsically
difficult problem. Threats vary greatly and evolve over time. The detection of threats based on manually-designed rules is therefore
difficult and requires a constant engineering effort. Machine-learning is a research area that revolves around the analysis of data and the discovery of patterns that describe aspects of the data. Discriminative learning methods extract prediction models from data that are optimized to predict a target attribute as accurately as possible. Machine-learning methods hold the promise of automatically identifying patterns that robustly and accurately detect threats. This thesis focuses on the design and analysis of discriminative learning methods for the two computer-security problems under investigation: email-campaign and malware detection.
The first part of this thesis addresses email-campaign detection. We focus on regular expressions as a syntactic framework, because regular expressions are intuitively comprehensible by security engineers and administrators, and they can be applied as a detection mechanism in an extremely efficient manner. In this setting, a prediction model is provided with exemplary messages from an email-spam campaign. The prediction model has to generate a regular expression that reveals the syntactic pattern that underlies the entire campaign, and that a security engineers finds comprehensible and feels confident enough to use the expression to blacklist further messages at the email server. We model this problem as two-stage learning problem with structured input and output spaces which can be solved using standard cutting plane methods. Therefore we develop an appropriate loss function, and derive a decoder for the resulting optimization problem.
The second part of this thesis deals with the problem of predicting whether a given JavaScript or PHP file is malicious or benign. Recent malware analysis techniques use static or dynamic features, or both. In fully dynamic analysis, the software or script is executed and observed for malicious behavior in a sandbox environment. By contrast, static analysis is based on features that can be extracted directly from the program file. In order to bypass static detection mechanisms, code obfuscation techniques are used to spread a malicious program file in many different syntactic variants. Deobfuscating the code before applying a static classifier can be subjected to mostly static code analysis and can overcome the problem of obfuscated malicious code, but on the other hand increases the computational costs of malware detection by an order of magnitude. In this thesis we present a cascaded architecture in which a classifier first performs a static analysis of the original code and -based on the outcome of this first classification step- the code may be deobfuscated and classified again. We explore several types of features including token $n$-grams, orthogonal sparse bigrams, subroutine-hashings, and syntax-tree features and study the robustness of detection methods and feature types against the evolution of malware over time. The developed tool scans very large file collections quickly and accurately.
Each model is evaluated on real-world data and compared to reference methods. Our approach of inferring regular expressions to filter emails belonging to an email spam campaigns leads to models with a high true-positive rate at a very low false-positive rate that is an order of magnitude lower than that of a commercial content-based filter. Our presented system -REx-SVMshort- is being used by a commercial email service provider and complements content-based and IP-address based filtering.
Our cascaded malware detection system is evaluated on a high-quality data set of almost 400,000 conspicuous PHP files and a collection of more than 1,00,000 JavaScript files. From our case study we can conclude that our system can quickly and accurately process large data collections at a low false-positive rate.
Geospatial data has become a natural part of a growing number of information systems and services in the economy, society, and people's personal lives. In particular, virtual 3D city and landscape models constitute valuable information sources within a wide variety of applications such as urban planning, navigation, tourist information, and disaster management. Today, these models are often visualized in detail to provide realistic imagery. However, a photorealistic rendering does not automatically lead to high image quality, with respect to an effective information transfer, which requires important or prioritized information to be interactively highlighted in a context-dependent manner.
Approaches in non-photorealistic renderings particularly consider a user's task and camera perspective when attempting optimal expression, recognition, and communication of important or prioritized information. However, the design and implementation of non-photorealistic rendering techniques for 3D geospatial data pose a number of challenges, especially when inherently complex geometry, appearance, and thematic data must be processed interactively. Hence, a promising technical foundation is established by the programmable and parallel computing architecture of graphics processing units.
This thesis proposes non-photorealistic rendering techniques that enable both the computation and selection of the abstraction level of 3D geospatial model contents according to user interaction and dynamically changing thematic information. To achieve this goal, the techniques integrate with hardware-accelerated rendering pipelines using shader technologies of graphics processing units for real-time image synthesis. The techniques employ principles of artistic rendering, cartographic generalization, and 3D semiotics—unlike photorealistic rendering—to synthesize illustrative renditions of geospatial feature type entities such as water surfaces, buildings, and infrastructure networks. In addition, this thesis contributes a generic system that enables to integrate different graphic styles—photorealistic and non-photorealistic—and provide their seamless transition according to user tasks, camera view, and image resolution.
Evaluations of the proposed techniques have demonstrated their significance to the field of geospatial information visualization including topics such as spatial perception, cognition, and mapping. In addition, the applications in illustrative and focus+context visualization have reflected their potential impact on optimizing the information transfer regarding factors such as cognitive load, integration of non-realistic information, visualization of uncertainty, and visualization on small displays.
The main objective of this dissertation is to analyse prerequisites, expectations, apprehensions, and attitudes of students studying computer science, who are willing to gain a bachelor degree. The research will also investigate in the students’ learning style according to the Felder-Silverman model. These investigations fall in the attempt to make an impact on reducing the “dropout”/shrinkage rate among students, and to suggest a better learning environment.
The first investigation starts with a survey that has been made at the computer science department at the University of Baghdad to investigate the attitudes of computer science students in an environment dominated by women, showing the differences in attitudes between male and female students in different study years. Students are accepted to university studies via a centrally controlled admission procedure depending mainly on their final score at school. This leads to a high percentage of students studying subjects they do not want. Our analysis shows that 75% of the female students do not regret studying computer science although it was not their first choice. And according to statistics over previous years, women manage to succeed in their study and often graduate on top of their class. We finish with a comparison of attitudes between the freshman students of two different cultures and two different university enrolment procedures (University of Baghdad, in Iraq, and the University of Potsdam, in Germany) both with opposite gender majority.
The second step of investigation took place at the department of computer science at the University of Potsdam in Germany and analyzes the learning styles of students studying the three major fields of study offered by the department (computer science, business informatics, and computer science teaching). Investigating the differences in learning styles between the students of those study fields who usually take some joint courses is important to be aware of which changes are necessary to be adopted in the teaching methods to address those different students. It was a two stage study using two questionnaires; the main one is based on the Index of Learning Styles Questionnaire of B. A. Solomon and R. M. Felder, and the second questionnaire was an investigation on the students’ attitudes towards the findings of their personal first questionnaire. Our analysis shows differences in the preferences of learning style between male and female students of the different study fields, as well as differences between students with the different specialties (computer science, business informatics, and computer science teaching).
The third investigation looks closely into the difficulties, issues, apprehensions and expectations of freshman students studying computer science. The study took place at the computer science department at the University of Potsdam with a volunteer sample of students. The goal is to determine and discuss the difficulties and issues that they are facing in their study that may lead them to think in dropping-out, changing the study field, or changing the university. The research continued with the same sample of students (with business informatics students being the majority) through more than three semesters. Difficulties and issues during the study were documented, as well as students’ attitudes, apprehensions, and expectations. Some of the professors and lecturers opinions and solutions to some students’ problems were also documented. Many participants had apprehensions and difficulties, especially towards informatics subjects. Some business informatics participants began to think of changing the university, in particular when they reached their third semester, others thought about changing their field of study. Till the end of this research, most of the participants continued in their studies (the study they have started with or the new study they have changed to) without leaving the higher education system.
Dieser Beitrag diskutiert die Konzeption eines Software-Projektpraktikums im Bereich E-Learning, welches Lehramts- und Fachstudierenden der Informatik ermöglicht, voneinander zu profitieren und praxisrelevante Ergebnisse generiert. Vorbereitungen, Organisation und Durchführung werden vorgestellt und diskutiert. Den Abschluss bildet ein Ausblick auf die Fortführung des Konzepts und den Ausbau des Forschungsgebietes.
Die Unterrichtsmethode Stationsarbeit kann verwendet werden, um Individualisierung und Differenzierung im Lernprozess zu ermöglichen. Dieser Beitrag schlägt Aufgabenformate vor, die in einer Stationsarbeit über das Klassendiagramm aus der Unified Modeling Language verwendet werden können. Die Aufgabenformate wurden bereits mit Studierenden erprobt.
Dieser Beitrag diskutiert den Einsatz von interaktiven und automatischen Theorembeweisern in der universitären Lehre. Moderne Theorembeweiser scheinen geeignet zur Implementierung des dialogischen Lernens und als E-Assessment-Werkzeug in der Logikausbilding. Exemplarisch skizzieren wir ein innovaties Lehrprojekt zum Thema „Komputationale Metaphysik“, in dem die zuvor genannten Werkzeuge eingesetzt werden.