1. © 2005-2006 The ATHENA Consortium. Ontology based support to Enterprise Interoperability

2. 2 © 2005-2006 The ATHENA Consortium. Contents Introduction Interoperability – Semantic viewpoint Requirements State-of-the-art Methods of Ontology building and maintenance Technologies Tools Concepts for ATHENA development Methodology adopted Architectures & Tools Conclusion

3. 3 © 2005-2006 The ATHENA Consortium. Introduction The course will enable participants to understand the objective and structure of the ATHENA Semantic Suite and how to apply it to solve some generic interoperability problems. Course introduction

4. 4 © 2005-2006 The ATHENA Consortium. Introduction The aim of this course is to present the students with the objective and structure of the ATHENA Knowledge Support and Semantic Mediation Solutions. Both, the conceptual level of the Ontology based support to Interoperability, which defines approach applied for interoperability using the ontology approach, and the technical level, which defines the technical and semantic interoperability infrastructure and supporting tools are covered. Some sample examples on how these tools can be used to address the solutions to general interoperability problem are provided. Course introduction

5. 5 © 2005-2006 The ATHENA Consortium. Contents Introduction Interoperability Issues – Semantic viewpoint Requirements State of the art Methods of Ontology building and maintenance Technologies Tools Concepts for ATHENA development Methodology adopted Architectures & Tools Conclusion

6. 6 © 2005-2006 The ATHENA Consortium. 10 100 1000 Cost Peers 10 100 O(n 2 ) EAI solution Athena L L H H Coop level Diversity Fax/Phone Custom EAI Athena Knowledge Support and Semantic Mediation Solutions Vision: to allow the (seamless) cooperation of two software applications that were not initially developed for this purpose. It will be possible without requiring to modify their software or their data organization. Logical Level of Integration: Any, Custom, Automatic. The Enterprise Logical Level of Integration may be defined: customizing their software or their data organization and using a middleware layer (EAI) These solutions are too expensive and inflexible to be used on a large scale Interoperability – Semantic viewpoint

7. 7 © 2005-2006 The ATHENA Consortium. Contents Introduction Interoperability Issues – Semantic viewpoint Requirements State of the art Methods of Ontology building and maintenance Technologies Tools Concepts for ATHENA development Methodology adopted Architectures & Tools Conclusion

8. 8 © 2005-2006 The ATHENA Consortium. Semantic Searching and Retrieval Models Transformation and Mapping Business Message Reconciliation Useful Semantic Services Consistency checking (absence of contradictions) Semantic matchmaking Semantic query and retrieval Transformation and Mappings, among conceptual models Semantic reconciliation of information structures (and messages) Requests and expectations

9. 9 © 2005-2006 The ATHENA Consortium. An extensive use of semantics, according to the ongoing most advanced research, provides the following services: Semantic Query Semantic Matchmaking Reasoning Transformation and Mapping Semantic basic services

10. 10 © 2005-2006 The ATHENA Consortium. P1. Semantic Searching and Retrieval P2. Models Transformation and Mapping P3. Web Services Composition and Execution P4. Business Protocol Mediation P5. Business Message Reconciliation Possible uses of Semantic services

11. 11 © 2005-2006 The ATHENA Consortium. Representation Requirements Ontology Modelling Templates Annotation Requirements Ontology-based Semantic Annotation Method Operational Requirements Ontology-based Services Possible uses of semantic services (in Athena) An example of Semantic-driven solution: Message Reconciliation Requirements

12. 12 © 2005-2006 The ATHENA Consortium. Different languages and different approaches for different purposes, e.g. Description of BPs for software design Specification of BPs for simulation Definition of BPs and related entities for understanding The Goal of the Ontology Modelling is a non ambiguous, shared understanding of a domain problem Representation Requirements: The purpose of the ontology modelling

13. 13 © 2005-2006 The ATHENA Consortium. OPAL: Object. Process, Actor Language Enterprise domain adequacy –not a general purpose ontology modelling language –elements (e.g., concept kinds) of the enterprise domain in the ontology language, for enriching the target ontology language –providing to the domain experts modelling templates that ease to specify the domain concepts Representation Requirements OPAL: an ontology modelling language

14. 14 © 2005-2006 The ATHENA Consortium. Actor –aimed at modelling any relevant entity of the domain that is able to activate or perform a process. (e.g. Buyer, Supplier) Object –aimed at modelling a passive entity, on which a process operates, typically to modify its state. (e.g., Purchase Order, Invoice) Process –aimed at modelling an activity that is performed by an actor to achieve a given goal. (e.g. Issuing Purchase Order, Sending Request for Quotation) The OPAL concepts are connected by conceptual relations (i.e.: generalisation, decomposition etc..) Representation Requirements OPAL: Main meta-concepts

15. 15 © 2005-2006 The ATHENA Consortium. The complete picture will include other Complementary concepts, such as: –Business Object Document –Atomic Attribute, Complex Attribute –Message, –State, –Goal, –Event, –Rule Complementary concepts are used to complete the definition of Primary Concepts Representation Requirements OPAL: Complementary meta-concepts

16. 16 © 2005-2006 The ATHENA Consortium. An Ontology-based Semantic Annotation is a formal expression Is associated to a resource (or part of it) provides an unambiguous and precise meaning An ontology-based semantic annotation is expressed in a formal representation language (OWL-like in our case) The annotation consists in 1. A term that identifies an ontology concept OR 2. An expression that identifies a new concept, derived from the ontology Ontology-based Semantic annotation

17. 17 © 2005-2006 The ATHENA Consortium. PupilStudent hasStud-IDAND =: Language constructor Ontology Term ConnectiveResource to be annotated PupilPerson=: Ontology TermsConnectiveResource to be annotated 1.The semantic content of the annotated resource is represented by an ontology concept 2.The semantic content of the annotated resource is derived by ontology concepts and properties An example of Semantic Annotation

18. 18 © 2005-2006 The ATHENA Consortium. –Annotation criteria: Kind of annotated resources: XSD, RDF(S), XMI light WSDL Used by: Human / Computer Positioning: attached annotation (without modifying the resource, multiple annotation of the same resource) Level of formality: progressive approach (from informal to formal) Terminology restriction: ontology-based annotation Abstraction level: annotation by concepts derived from RO –Structured –Structured annotation expression using specific operators –Annotation linked to resource by using specific operators more or less general than the annotated resource –Annotation beyond exact matching: SAX can be more or less general than the annotated resource –Using domain ontologies –Automatic Support to annotation building –Web Application Requirements for semantic annotation

19. 19 © 2005-2006 The ATHENA Consortium. –Rules criteria: Reconciled resources: document models expressed using the RDF(S) Defined by: Human Executed by: Computer Positioning: rules stored into a Repository, models not modified Terminology restriction: ontology-based rules Abstraction level: rules must be executable by applications (Ares) –Using domain ontologies –Automatic Support to reconciliation rules generation –Web Application Requirements for the reconciliation rules

20. 20 © 2005-2006 The ATHENA Consortium. Contents Introduction Interoperability Issues – Semantic viewpoint Requirements State of the art Methods of Ontology building and maintenance Technologies Tools Concepts for ATHENA development Methodology adopted Architectures & Tools Conclusion

21. 21 © 2005-2006 The ATHENA Consortium. Ontology modelling languages, Ontology management systems, Inference engines, Ontology content. State of Art

22. 22 © 2005-2006 The ATHENA Consortium. We have identified the following families of languages: Diagrammatic languages Frame-oriented languages Logic-based languages Web-oriented languages Process-oriented languages None of the analysed languages meets all the requirements for the language to be used within ATHENA: Business oriented constructs Reasoning support Expressive power to represent process ontologies That’s why in Athena it is used OPAL (Object, Process, Actor modelling Language) State of Art - Ontology modelling languages

23. 23 © 2005-2006 The ATHENA Consortium. Broad number of OMS analysed, among which: –KAON –Protégé –pOWL –Ontolingua (with Chimera) –OilEd and evaluated against the following criteria: –Application domain adequacy –Availability of reasoning systems –Advanced query –Constraints language –Web-orientation In Athena it has been decided to develop Athos (Athena Ontology System). State of Art - Ontology management systems

24. 24 © 2005-2006 The ATHENA Consortium. Reasoning facilities are a key element of a semantics-based solution. The five of the most relevant inference engines have been analysed: –Jess –Jena2 –Racer –Metalog –SWAP/CWM State of Art - Inference engines

25. 25 © 2005-2006 The ATHENA Consortium. Contents Introduction Interoperability Issues – Semantic viewpoint Requirements State-of-the-art Methods of Ontology building and maintenance Technologies Tools Concepts for ATHENA development Methodology adopted Architectures & Tools Conclusion

26. 26 © 2005-2006 The ATHENA Consortium. Preparing Interoperability Doing Business Internet WS Local Software & Data SwApp#1 Sem Rec Rules #1 semIx Reference Ontology Sem Annot Set #1 Sem Rec Rules #2 Sem Annot Set #2 Local Software & Data SwApp#1 Legend Sem: Semantic; Annot: Annotation; Rec: Reconciliati on; semLx: Semantic Links?? SwApp: Software Application; Contributions to solve the problems

27. 27 © 2005-2006 The ATHENA Consortium. A progressive approach SA methodology defined as a stepwise approach Full SA expresses in OWL DL Simple SA Path SA Terminological SA, using RO terminology

28. 28 © 2005-2006 The ATHENA Consortium. The Annotation expression is a complex OWL DL expression. Ex: FSA (Buyer.hasTelephone.AreaCodeandContryCode)>: ( 8 relCountryCode_isPartOf.( 8 Telephone_isPartOf. ( 8 ContacInfo_isAttributeOf.Buyer))) a complex operator ( 8 relAreaCode_isPartOf.( 8 Telephone_isPartOf. ( 8 ContacInfo_isAttributeOf.Buyer))) The Annotation expression is built on SP previously identified and applying φ and © operators Ex. SSA (Buyer.hasTelephone.AreaCodeandContryCode)>: Buyer_BA.HasContactInfo.HasPartTelephone.HasPartAreaCode © Buyer_BA.HasContactInfo.HasPartTelephone.HasPartCountryCode Is built a Semantic Path vector using terms previous identified. Ex: PSA (Buyer.hasTelephone.AreaCodeandContryCode)>: [ Buyer_BA.HasContactInfo.HasPartTelephone.HasPartAreaCode, Buyer_BA.HasContactInfo.HasPartTelephone.HasPartCountryCode ] To annotate resource we use a vector of keywords (selected from the ontology terminology) Ex: TSA( Buyer)=:[Buyer_BA] TSA (hasTelephone)=:[hasPartTelephone] TSA (areaCodeandCountryCode)=:[ hasAreaCode, hasCountryCode ] Full SA (OWL DL) Path SA Terminological SA l=1 l=2 l=4 Simple SA l=3 Users Business people Domain Expert (O.O. expert) Domain Expert/ Knowledge Engineering Description Levels Multilevel methodology to annotate

29. 29 © 2005-2006 The ATHENA Consortium. ARGOS Reconciliation Rules Generator Reconc Rules ARES B Reconciliation Engine MSG A (SOAP) MSG B (SOAP) A Sem. Reconciliation Athos Reference Ontology Management System A* Semantic Annotation tool Annotation Repository Design TimeRun Time EM & BP BOD WS Semantic Search Engine Sem. Search S emantic A nnotation E x pressions (SAX) Semantic Annotation: Reference Architecture

30. 30 © 2005-2006 The ATHENA Consortium. Athos for Reference Ontology management: –Ontologies as an agreed and shared representation of a given domain. –in Athos ontologies are represented according to OPAL A* for Semantic annotation: –Semantic annotation aims at giving a non ambiguous meaning to digital resources –represents a conceptual correspondence between resources and concepts in the ontology ARGOS for Reconciliation Rules creation: –based on the Semantic annotation, Reconciliation Rules represent a procedural way of transforming ground resources (i.e., data) into ontology instances (forward transf.) and viceversa (backward transf.) ARES for Reconciliation: –the actual reconciliation is the result of the composition of a fwd transf and a bwd transf Semantic Suite components (TOOLS)…

31. 31 © 2005-2006 The ATHENA Consortium. Semantic Search and Retrieval System (as part of WP A6.2): –Queries are done against semantic annotation expressions (Semantic Annotation Repository) –Queries can be expressed by using a controlled vocabulary –Queries resolution can be helped by leveraging on reasoning on the ontology (i.e., taxonomic reasoning) –Original resources are retrieved since there is a link between annotation expressions and annotated resources …Semantic Suite components (TOOLS)

32. 32 © 2005-2006 The ATHENA Consortium. Based on the OPAL (Object, Process, Actor Language) methodology for the ontology representation Allows to build business domain ontologies Web application Developed under the Zope platform Web service enabled Plug-in enabled ATHOS OMS (Athena Ontology management System)

33. 33 © 2005-2006 The ATHENA Consortium. Some functionalities of Athos are exposed as web services in order to allow accessibility to the Ontology services by other software applications –Query an Ontology: given a search criteria, returns a set of pairs, composed of label and kind, corresponding to the concepts that match the search criteria –Retrieve a whole ontology: –Retrieve a Concept: given a label and a kind the corresponding Concept, if exists, will be returned –Retrieve the Specialization Hierarchy: returns the specialization hierarchy –Retrieve a Relation: given a label and a kind (identifying a concept), and a type of OPAL relation, it returns all the concepts that are linked to the given concept through that relation ATHOS interfaces

34. 34 © 2005-2006 The ATHENA Consortium. Ontology-based annotation tool XSD, RDF(S) and XMI (light) as kinds of resources that can be annotated Annotation is linked to the resource without modifying the resource itself (attached annot.) Progressive approach based on four levels: –Terminological (Keyword-based) –Path-based (Ontology structure-based) –Simple Semantic Annotation (abstract syntax) –Full Semantic Annotation (OWL-based) Web application developed under Zope A* (Athena Semantic Tool for Annotation of digital Resources)

35. 35 © 2005-2006 The ATHENA Consortium. Access to annotations are managed by the Annotation Repository Annotation repository Web service enabled Allows retrieval of annotations by different criteria based on –Annotated resource –Annotation –Metadata, such as author, date. A* interfaces

36. 36 © 2005-2006 The ATHENA Consortium. Reconciliation rules necessary to bridge the incompatibilities that arise when two interacting e-Services are not compliant describe how the semantic content of an information source (a business document) must be re-structured (possibly with some losses) to be compliant with the Reference Ontology Reconciliation of MESSAGES exchanged by WEB SERVICES Objective of Reconciliation

37. 37 © 2005-2006 The ATHENA Consortium. Used at run time by the Reconciliation Engine (ARES) to perform the correct transformation on the documents (instances) exchanged by two e-services Defined at design-time Bi-directional transformations: Transformations of a document model to/from a canonical form Usage of Reconciliation Rules

38. 38 © 2005-2006 The ATHENA Consortium. Annotations provide the semantic of parts of document models, but potentially at an abstract level (Specification) Within the reconciliation rules the semantic is made explicit at an operational level (Implementation) NOTE: Reconciliation rules can be defined independently from the annotations From Annotations to Reconciliation Rules

39. 39 © 2005-2006 The ATHENA Consortium. 7 ARES ARES Reconciliation Engine STEP1 STEP2 RO AMAM BMBM A In B In ARGOS RO ARGOS RR A  RO RR RO  A RR B  RO RR RO  B Reconciliation Rules Repository Design time Run time ARES ARES Reconciliation Engine RR A  RO RR RO  B Reconciliation Rules Repository Intermediate representation of A compliant with the RO A In RO Reconciliation rules for document transformation

40. 40 © 2005-2006 The ATHENA Consortium. A graphical environment supporting a user in defining transformation rules guided by –Document model –Annotations –Reference Ontology –A set of Macro Rules using an abstract but expressive syntax An intuitive interface supports the user in parameterizing transformation templates (Macro Rules) Instantiated Rules are automatically transformed by ARGOS into executable code (Jena rules) for the reconciliation engine (ARES) ARGOS: a Reconciliation Rules Generation tool

41. 41 © 2005-2006 The ATHENA Consortium. The most common kinds of interoperability clashes occurring within documents have been analysed Each Macro Rule represents a Transformation that can be applied to solve a clash Main ARGOS Macro Rules: –Merge –Split –Map –MapValue –Convert –Sum –Mult ARGOS: Macro Rules

42. 42 © 2005-2006 The ATHENA Consortium. ODBC ARGOS Argos Client (GUI) Argos Client (GUI) Rules Generator Rules Generator Rules Repository. HTTP/HTML Type Checker Type Checker Functor Library Functor Library Web Services Module OntoViz ResViz USED SERVICES getOntologiesList () getRDFModelsList () getRDFVisualisation (URI rdf_uri) getOntoVisualisation (URI onto_uri) getAnnotations (URI rdf_uri) PROVIDED SERVICES getRules (URI res_uri) ARES THEMIS ATHOS A* Repository connector Java ARGOS macro architecture

43. 43 © 2005-2006 The ATHENA Consortium. A reconciliation and mediation platform that, at runtime, is able to intercept data and transform them to allow for cooperation between web services Implemented by an engine for the run-time application of the reconciliation rules defined by ARGOS Must be integrated into a Web Services mediator/bridge Maintain a log system that can be used to provides feedbacks to ARGOS about the application of the rules ARES

44. 44 © 2005-2006 The ATHENA Consortium. Semantic Mediation engine, able to –apply the rules associated to the model of the document to be dispatched –to generate log files recording information about the application of the rules and errors that have been generated Log Repository: to store the log files Log Repository Connector: providing access to the log files to external applications (i.e.: ARGOS) Logs Inspector: to visualise measures and other information contained in the log files Ares GUI: a simple interface for control and administration of the system ARES Components

45. 45 © 2005-2006 The ATHENA Consortium. ARES Ares GUI Semantic Mediation Engine Semantic Mediation Engine Log Repository HTTP/HTML Web Services Module USED SERVICES getRules (URI res_uri) getRDFModel (URI res_uri) PROVIDED SERVICES getMediation (URI in_res_uri, URI out_res_uri, String in_msg) getLogsByURI (URI res_uri) … ARGOS Web Service Bridge Web Service Bridge A* Java RDF documents Repository THEMIS SOAP Repository connector Logs inspector GUI Logs inspector GUI SOAP Java ARES architecture

46. 46 © 2005-2006 The ATHENA Consortium. Messages should have an RDF format (valid instances of RDF Schemas) Reconciliation rules are JENA2 inference rules ARES Engine is a Java application enriched with JENA APIs that exports ARES Requirements and Technologies

47. 47 © 2005-2006 The ATHENA Consortium. Logical Physical Operational Service A Service B ARGOS Web Service Bridge Log Connector maintains Logs Repository populates analyses Retrieves measures about rules application Invokes service B sending message M ARES Reconciliation Rules Repository Receives message M’ obtained by ARES applying the rules Rules Rep Connector Retrieves rules that have to be applied to M to generate M’ ARES integration into a run-time environment

48. 48 © 2005-2006 The ATHENA Consortium. This course has been developed under the funding of the EC with the support of the EC ATHENA-IP Project. Disclaimer and Copyright Notice: Permission is granted without fee for personal or educational (non-profit) use, previous notification is needed. For notification purposes, please, address to the ATHENA Training Programme Chair at rg@uninova.pt. In other cases please, contact at the same e_mail address for use conditions. Some of the figures presented in this course are freely inspired by others reported in referenced works/sources. For such figures copyright and all rights therein are maintained by the original authors or by other copyright holders. It is understood that all persons copying these figures will adhere to the terms and constraints invoked by each copyright holder.rg@uninova.pt