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UNCERTAINTY AWARE TEMPORAL RELATIONSHIP MODELLING IN KNOWLEDGE GRAPHS

dc.contributor.authorRamachandran, Deepa
dc.contributor.copyright-releaseNot Applicable
dc.contributor.degreeMaster of Computer Science
dc.contributor.departmentFaculty of Computer Science
dc.contributor.ethics-approvalNot Applicable
dc.contributor.external-examinerna
dc.contributor.manuscriptsNot Applicable
dc.contributor.thesis-readerDr. Evangelos Milios
dc.contributor.thesis-readerDr. Gabriel Spadon De Souza
dc.contributor.thesis-supervisorDr. Ga Wu
dc.contributor.thesis-supervisorDr. Frank Rudzicz
dc.date.accessioned2025-12-15T19:32:48Z
dc.date.available2025-12-15T19:32:48Z
dc.date.defence2025-12-08
dc.date.issued2025-12-15
dc.descriptionPTRM models temporal uncertainty in knowledge graphs through distributional event embeddings and probabilistic overlap computation, replacing fixed temporal thresholds with learned probability distributions. Experiments on ICEWS and GDELT datasets demonstrate 27-40 percentage point improvements over state-of-the-art baselines with strong calibration (ECE=0.148-0.363), advancing temporal reasoning capabilities for applications requiring uncertainty-aware predictions under variable temporal dynamics
dc.description.abstractExisting approaches for constructing knowledge graphs (KGs) from text sources effectively capture structural relationships but often struggle to represent the temporal uncertainty inherent in event-based information. Their temporal encoding typically relies on exact timestamp matching, which limits the ability to handle natural temporal variation among events. This thesis introduces Probabilistic Temporal Relationship Modeling (PTRM), a framework that represents events as temporal distributions to capture uncertainty in timing and relationship propagation. PTRM employs distributional embeddings that jointly encode semantic and temporal uncertainty, enabling soft temporal matching through probabilistic overlap computation. Experiments involving 200,000 events from the ICEWS and GDELT datasets demonstrate that PTRM substantially outperforms existing baselines, including temporal knowledge graph embedding methods and classical approaches, while maintaining strong calibration properties essential for decision-critical applications. The results demonstrate that PTRM bridges the gap between rigid timestamp-based methods and the temporal flexibility required for real-world reasoning, achieving state-of-the-art performance in temporal relationship inference under uncertainty.
dc.identifier.urihttps://hdl.handle.net/10222/85565
dc.language.isoen
dc.subjectTemporal knowledge graphs
dc.subjectuncertainty quantification
dc.titleUNCERTAINTY AWARE TEMPORAL RELATIONSHIP MODELLING IN KNOWLEDGE GRAPHS

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