ontology

问题 I am trying to practice myself in writing some SPARQL queries. Does anybody know where I can find the best material? Where I can find some RDF file and some tasks to try to write my own SPARQL queries. I am good with SQL, and I just need some material to learn to write in SPARQL. 回答1: All sample RDF and queries from the O'Reilly book "Learning SPARQL" are available on the book's home page at learningsparql.com. (Full disclosure: I wrote it.) 回答2: data.gov and DataHub have a lot of

问题 My query (excerpt) is roughly this. CONSTRUCT { ?publication fb:type ?type; fb:publicationType ?publicationType; } WHERE { ?publication a bibo:Document . ?publication vitro:mostSpecificType ?publicationType . } And it returns output similar to... <rdf:Description rdf:about="https://abcd.fgh/individual/publication12345"> <fb:publication>Example pub title</fb:publication> <fb:publicationType rdf:resource="http://purl.org/ontology/bibo/AcademicArticle"/> </rdf:Description> Perhaps a beginner

问题 So, I have an Ontology and need some help with my SPARQL-queries. The ontology is based on different beer ingredients and equipment for brewing. For instance, it has the class "Ingredients", and a subclass "Malt/Grain", and then a subclass "Dark". Now I have some different, more specific types of dark malts, that are individuals, and members of the class Dark. If I go into one individual in Protege, for instance "Dark_Crystal", will have "Dark" under its field of "Types" So, I want to be able

问题 I am working on an ontology task in Protege . Situation: I have Student class that has subclasses of InactiveStudent , ActiveStudent and VeryActiveStudent . These subclasses have conditions related to object property called isEnrolledForSubject . I defined conditions for: ActiveStudent = 'Class of all students' and (isEnrolledForSubject min 1 'Class of all subjects') VeryActiveStudent = 'Class of all students' and (isEnrolledForSubject min 4 'Class of all subjects') but I don't know how to

问题 Is there any tool to quickly get a relational database from an owl ontology? 回答1: OWL2ToRDB is a Protégé plugin that can convert an owl ontology into RDB. 来源： https://stackoverflow.com/questions/43762837/convert-an-owl-ontology-into-a-relational-database

问题 In my ontology, I have two individuals of type abc:Invention : abc:InventionA rdf:type abc:Invention . abc:InventionB rdf:type abc:Invention . and 2 individuals of type abc:MarketSector , linked with an object property abc:includedIn : abc:MrktSctrA rdf:type abc:MarketSector . abc:MrktSctrB rdf:type abc:MarketSector . abc:MrktSctrB abc:includedIn MrktSctrA . Currently, InventionA and InventionB are linked with, respectively MrktSctrA and MrktSctrB via an object property abc:targets : abc

问题 I have a set of football related keywords, a data set of positive sentiments words and negative sentiments words with me. My requirement is to combine these and search is social media to get some real time discussions and posts, and do some statistical analysis and reach some conclusions. This keywords and data sets are dynamically updating one. Now my question is What is the best practice to handle the three sets of data? Using an Ontology structure or Well structured database? Whether the

问题 I am a geographer and a new comer in the field of ontology trying to make sense out of these two. Therefore, I have created a simple ontology, as follows: Thing Feature Lane Segment(equivalent to Arc) Geometry Arc (equivalent to Segment) Node Dangling_Node Intersection_node you can find the .owl file here instantiated with a very simple spatial road dataset (fig1). the ontology is consistent without and with instances, but when I run the reasoner, the Dangling_node instances (nodes that are

问题 This question already has an answer here : SPARQL full aggregation on a group aggregation (1 answer) Closed 3 years ago . I have this query: prefix : <http://test.example/> select ?anotherUser (COUNT(?anotherItem) as ?countOfSharedLikedItems) WHERE { values ?user {:ania}. ?anotherUser :likes ?anotherItem. filter (?anotherUser != ?user) filter exists {?user :likes ?anotherItem} } group by ?anotherUser order by desc(?countOfSharedLikedItems) That runs on this data: @prefix : <http://test

问题 I'm looking for a general purpose API/web service/tool/etc... that allows convert a given HTML page to an RDF graph as specific as possible (most probably using a back bone ontology and/or mapper). 回答1: Have you proved GRDDL? GRDDL is a technique for obtaining RDF data from XML documents and in particular XHTML pages. 回答2: I used XQuery to extract the data out of the given set of web pages. I had to write custom queries for the web pages. I think this is the most straight forward approach to