Core Concepts
This paper proposes an automated framework, TKGCon, to construct fine-grained, theme-specific knowledge graphs (ThemeKGs) from raw theme-specific documents, addressing the limitations of existing knowledge graphs in information granularity and timeliness.
Abstract
The paper introduces the concept of theme-specific knowledge graphs (ThemeKGs) to address the limitations of existing knowledge graphs in terms of information granularity and timeliness. The proposed TKGCon framework consists of two main components:
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Theme Ontology Construction:
- Entity Ontology: Leverages Wikipedia's category hierarchy to construct a high-level entity ontology for the given theme.
- Relation Ontology: Uses large language models (LLMs) to generate potential relation candidates between entity categories in the ontology.
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Theme KG Construction:
- Entity Recognition and Typing: Extracts entity mentions from the theme-specific documents and maps them to the closest categories in the entity ontology.
- Relation Retrieval and Extraction: Retrieves candidate relations from the relation ontology based on the entity pairs, and then selects the most suitable relation using the contextual information.
The framework is evaluated on two theme-specific datasets, EV battery and Hamas-attack-on-Israel (2023), and outperforms various baseline methods in terms of entity recognition, relation extraction, and theme coherence. The constructed ThemeKGs contain more fine-grained, theme-specific entities and relations compared to existing general knowledge graphs.
Stats
Lead-acid batteries have low energy density.
Deep cycle batteries are used to provide continuous electricity to run electric vehicles like forklifts.
Flooded lead-acid batteries are a type of vehicle batteries.
Automobile engine starter batteries are different from deep cycle batteries.
Quotes
"Despite the broad applications of knowledge graphs, there are two major issues attached to the existing KGs, even in the current era of large language models (LLMs). The first issue is the limited information granularity of existing KGs. Existing KGs, including the domain-specific ones, often integrate numerous sources of texts and cover comprehensive information on a topic. They are designed for general public and do not address detailed, fine-grained information for theme-specific researchers."
"The second issue is the lack of timeliness in existing KGs. It is hard for a KG to keep pace with the dynamics of the real world, especially for rapid changing events, since such updates often require huge efforts of human/expert annotation and guidance."