data science winter school note

Juanzi Li

Tsinghua University

Future focus

1. Better search methds
2. Semantics intergration
3. Reasoning

Ontology

Ontology is the philosophical study of the nature of being, becoming, existence or reality as well as the basic categories of being and their relations.

Ontology in computer science

• Conceptualization
• Explict
• Formal
• Share

Ontology Formalization

$$O = {C,R.F,A,I}$$

• Concepts
• Relations
• Functions
• Axioms
• Instances

Knowledge Graph

The Knowledge Graph is a knowledge base used by Google to enhance its search engine’s search results with semantic-search information gathered from a wide variety of sources. 

knowledge graph is the structured representation of processed data.

what can it do

1. Annotated entities and relations-semantic intergration
2. Indexing and retrieving entities and relations not just string-search from string to entities and relation
3. Quenstion-answering
4. Inferring new facts:learning rules from KG
5. Data analysis based on KG
6. Add meaning to the web observatory
7. Give analysis and interpretation about real world

Limitations of existing knowledge graph

1. Imbalance of knowladge in difference language
2. low integration of multilingual knowledge
3. lack of research on the knowledge complement of different language

Reference :

The Semantic Web. By Tim Berners-Lee, James Hendler and Ora Lassila on May 1, 2001 Scientific American

Wikidata

RDF

The Resource Description Framework (RDF) is a family of World Wide Web Consortium (W3C) specifications[1] originally designed as a metadata data model. It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax notations and data serialization formats. It is also used in knowledge management applications.