Layers of Abstraction to Semantic Web Programming

Transcription

1 Reasoning Applications activity UML Activity Diagrams EPC Diagrams... activity split decision-split join decision-and decision-or decision-xor join-and join-or join-xor start decision-join end followed-by epc-function event epc-resource followed-by has-resource node Graph-based Models model-package node-type subnode-type node edge-type edge corresponds-to uses instance Semantic Web Concepts rdfs-class subclass instance property subproperty superproperty inverse-property transitive reification Introducing define-concept Concept Generator triple triple AllegroGraph + Utils Layers of Abstraction to Semantic Web Programming Concept Framework Allegro Common Lisp + Utils SWWS 2011 Prof. Bernhard Humm, Ph.D., Alexey Korobov, M.Sc. Faculty of Computer Science Hochschule Darmstadt University of Applied Sciences October 20 th, 2011 uses Allegro Prolog + Utils uses 1

2 Developing ontologies and Semantic Web applications today Developing ontology schema Asserting statements Specifying and executing queries Specifying rules and inferencing 2

3 Developing ontology schema Graphical ontology development environment, e.g., Protégé, TopBraid Composer 3

4 Asserting statements Frameworks, e.g., Jena, Sesame ca. 10 LOC for adding a single tiple 4

5 Specifying and executing queries Frameworks, e.g., Jena, Sesame ca. 25 LOC for a simple query Similarly for specifying rules and inferencing 5

6 Problem: Missing abstraction mechanisms Not appropriate 10 LOC for single triple 25 LOC for simple query Not integrated SPARQL not embedded in Java N3 not embedded in Java No user-defined functions in SPARQL, N3 Redundant No named, parameterized SPARQL queries Redundant structures in assertions and queries 6

7 Solution: Concept Framework DSL for concept definition (define-concept instance (uri class &optional label comment) (triple uri!rdf:type class) (triple uri!rdfs:label label) (triple uri!rdfs:comment comment)) Concepts have names and parameters Primitive concepts are based on bare triples only (define-concept node (uri node-type graph label &optional comment) (cond (sub-class node-type!modl:node)) (instance uri node-type label comment) (triple graph!modl:contains uri)) Compound concepts are based on other concepts Advanced features: optional parameters, local variables, conditions, name spaces 7

8 Concept specification defines Assertions and Queries Concept DSL Concept Specification (example) (define-concept node (uri node-type graph label &optional comment) (cond (sub-class node-type!modl:node)) (instance uri node-type label comment) (triple graph!modl:contains uri)) Code Generation Asserting Statements (example of usage) (node!trv:req-app!uml:activity!trv:uml "request approval") Reasoning and Querying (example of usage) (select?label (node nil!uml:activity nil?label)) AllegroGraph AllegroProlog 8

9 Introducing Layers of Abstraction to Semantic Web Programming Reasoning Applications activity UML Activity Diagrams EPC Diagrams... activity split decision-split join decision-and decision-or decision-xor join-and join-or join-xor start decision-join end followed-by epc-function event epc-resource followed-by has-resource node Graph-based Models model-package node-type subnode-type node edge-type edge corresponds-to uses instance Semantic Web Concepts rdfs-class subclass instance property subproperty superproperty inverse-property transitive reification uses uses Concept Framework define-concept triple Concept Generator triple AllegroGraph + Utils Allegro Prolog + Utils Allegro Common Lisp + Utils 9

10 Rules and custom queries (<- (label=?label?n1?n2?d1?d2) (node?n1 nil?d1?label) (node?n2 nil?d2?label)) Find equivalent labels in any two diagrams Find equivalent labels in specified diagram Find duplicate labels within diagrams (select-distinct (?label?d1?d2) (select-distinct (label=?label?n1 (?label?n2?d1?d1)?d2)) (select-distinct (label=?label?n1 (?label?n2?d1?d1)!x:y)) (label=?label?n1?n2?d1?d1)) SELECT DISTINCT?label?d1?d2 WHERE SELECT SELECT { DISTINCT?label?label?d1?d1 WHERE WHERE {?d1 { modl:contains?n1.?d1?n1 modl:contains?d1 rdfs:label modl:contains?n1.?label.?n1.?n1?d2 rdfs:label?n1 modl:contains rdfs:label?label.?label.?n2.?d1?n2 modl:contains x:y rdfs:label modl:contains?n2.?label.?n2. }?n2 rdfs:label?n2 rdfs:label?label.?label. } FILTER (?n1!=?n2) } 10

11 Conclusions Severe problems in developing ontologies and Semantic Web applications today Not appropriate Not integrated Redundant Concept Framework shows enormous improvements But: based on exotic environment (Lisp, Prolog) Challenge Port idea and implementation to mainstream platforms, e.g., Java 11

12 Introducing Layers of Abstraction to Semantic Web Programming Prof. Bernhard Humm, Ph.D. Faculty of Computer Science Hochschule Darmstadt University of Applied Sciences 12