12: Ontology Engineering Flashcards
What are the four types of categories?
- Domains (in databases)
- Types (in Artificial Intelligence)
- Classes (in object-oriented programming)
- Concepts (in logic)
Write a SPARQL command to find the first 50 concepts of DBpedia
and test your query in http://dbpedia.org/sparql
SELECT DISTINCT ?concept
WHERE {
?s a ?concept .
} LIMIT 50
Write a SPARQL command to find whether or not Amazon river is longer than the Nile River
and then test your query in http://dbpedia.org/sparql
PREFIX prop: http:></http:
ASK
{
http:> prop:length ?amazon .</http:
http:> prop:length ?nile .</http:
FILTER(?amazon > ?nile) .
}
What are integrated vocabularies? Give an example of one.
The merging of independently developed vocabularies into a single large resource
i.e. Unified Medical Language System which has integrated 100 biomedical vocabularies
What are the problems with manual ontology acquisition?
- Time-consuming
- Expensive
- Highly skilled
- Cumbersome task
What are the tasks supported by machine learning?
- Extraction of ontologies from existing data on the Web
- Extraction of relational data and metadata from existing data on the Web
- Merging and mapping ontologies by analysing extensions of concepts
- Maintaining ontologies by analysing instance data
What are some useful Machine Learning techniques for Ontology Engineering?
- Clustering
- Incremental ontology updating
- Support for knowledge engineering
- Improving large natural language ontologies
- Ontology learning
What are the current major approaches in ontology mapping?
- Linguistic
- Statistical
- Structural
- Logical methods
Describe the linguistic methods in ontology mapping.
Exploiting the linguistic labels attached to the concepts in source and target ontology in order to discover potential matches
Describe the statistical methods in ontology mapping.
- A significant statistical correlation between the instances of a source concept and a target concept, gives us reason to believe that these concepts are strongly related
- Relies on the availability of a sufficiently large amount of instances that are classified in both the source and the target ontologies
Describe the structural methods in ontology mapping.
- Since ontologies have internal structure, it makes sense to exploit the graph structure of the source and the target ontologies and try to determine similarities, often in coordination with other methods
Describe the logical methods in ontology mapping.
- The most specific to mapping ontologies
- A serious limitation of this approach is that many practical ontologies don’t carry much logical formalism with them
- In any case, if an ontology carries heavy logical formalism, logical methods can be effectively used for its mapping
What are the methods involved in building the Semantic Web architecture?
- Knowledge acquisition
- Knowledge storage
- Query Languages, for processing the knowledge stored, and
- Knowledge maintenance
____ are the base of any knowledge representation system.
Rules are the base of any knowledge representation system.
The main aim of the Semantic Web is to enable the ____ of structured and semi-structured data sources over the Web
The main aim of the Semantic Web is to enable the integration of structured and semi-structured data sources over the Web
First, create any simple wild-life ontology including its class hierarchy, properties, and restrictions.
-
Properties:
- eats: inverse of eaten-by
- is-part-of: transitive
- Examples:
- branch is-part-of tree
- leaf is-part-of branch
- Examples:
-
Restrictions:
- carnivore: animals which eat animal
- herbivore: animals which each eat leaves
Based on the database facts in the image, write a pair of rules showing X is a half-sister of Y.
female(X),mother(M,X), mother(M,Y), father(F1,X), father(F2,Y), notSame (F1,F2) -> half-sister(X,Y)
female(X), father(F,X), father(F,Y),mother(M1,X), mother(M2,Y), notSame (M1,M2) -> half-sister(X,Y)
