Lecture 02: Semantic Web Flashcards
What is a Resource?
A resource is the conceptual mapping to an entity or set of entities. It can be either:
- Network-retrievable: electronic document, image, a service etc.
- Not network-retrievable: human beings, corporations, books in libraries etc.
What is an Identifier?
An object that can act as reference to something that has identity?
What is a Uniform Resource Identifier (URI)?
A URI is a sequence of characters used for uniquely identifying resources with the following syntax:
scheme : // authority path [? query] [# fragment]
The URI allow for computers to easily identify resources as standard names are ambiguous.
What is the ‘Scheme’ part of the URI?
The scheme is the top level of the URI and is sometimes particular designed for a specific protocol and may have the same name as that protocol.
What is the ‘Authority’ part of the URI?
The authority is the second level of the URI which governs the remaining namespaces within the URI. Typically defined by a DNS name or a scheme-specific registry.
What is the ‘Path’ part of the URI?
The path is the third level of the URI and contains data specific to the authority or scheme if an authority is not specified. It also identifies the resources within the scope of that authority or scheme.
What is the ‘Query’ part of the URI?
The query is the fourth level of the URI and contains a string of information to be interpreted by the resource.
What is the ‘Fragment’ part of the URI?
The fragment is the final level of the URI is an indirect identification of the secondary resource - that resource may be:
- A portion or subset of the primary resource;
- A view or representation of the primary resource;
- Another resource defined or described by those representations.
What is the Escaped Representation of a Character?
The Escaped Representation of a Character is regarding making use of characters which are reserved for a URI. These characters are overcome by a triplet, made up of - a percent character and two hexadecimal digits which are machine parsable , which allows to print a usually reserved character.
What is the Resource Description Format (RDF) ?
The RDF is a data model that express facts with three-part statements known as triples which are used to serialise data. RDF allows for the harnessing and connectivity of data. The triples have the following syntax:
.
What are Literals?
Literals is a means by identifying values through lexical representations, such as dates and numbers.
What is SPARQL Query?
SPARQL query is a standard language to query graph data which is represented by RDF triples. With the following structure:
- PREFIX (Defintion of Prefixes)
- SELECT (Type of Query)
- WHERE (RDF triple patterns and conditions)
What is the Web Ontology Language OWL?
Manchester OWL is a web ontology language which is used for defining relationships. It relies on structured information and inference rules in order to reason the relationship between different data resources. Manchester OWL uses the Open World Assumption, cannot assume all information is known about all individuals in the domain.
What does the OWL TBox involve?
The OWL TBox does not operate under the unique name assumption, individuals and classes are not distinct unless explicitly stated.
