Overview of Semantic Tools
Semantic Technology Boot Camp
Day 3
2
Overview
▼
Categories of Semantic
Tools
▼
Category Overview
Purpose & Role in Architecture
Example Tools
Tradeoffs and Evaluation Criteria
3
Categories of Semantic Tools
▼
RDF
Parsers
▼
Triplestores
▼
Ontology Editors & Workbenches
▼
SPARQL Query Engines
▼
Reasoners
▼
Middleware & Servers
▼
Ontology Documentation Tools
▼
Web Development Kits
▼
Specialty Libraries
4
RDF Parsers
Like an XML parser, an RDF parser is a software library that
will interpret an RDF dataset (or ontology) and construct a
memory model of the graph described.
▼
Open Source: Jena, OWLAPI, Raptor.
5
Triplestores
A
triplestore
(also “triple store”) is a type of database
optimized for the storage and retrieval of RDF data.
▼
Commercial stores:
Allegrograph
,
Stardog
▼
Open Source stores: Virtuoso, Sesame,
Mulgara
6
Ontology Editors & Workbenches
An ontology editor offers a visual interface for the
composition of OWL ontologies. Many editors go
further and offer facilities for ontology publishing, batch
operations and script processing over a set of
ontologies.
▼
Commercial:
TopBraid
Composer
▼
Open
Source: Protégé,
NeOn
Toolkit
7
SPARQL Query Engines
A SPARQL query engine will evaluate a SPARQL
expression over a specified graph and return an
appropriate response for the expression type (ASK,
CONSTRUCT, DELETE, SELECT, etc.).
▼
OpenSource
: ARQ
8
Reasoners
A semantic
reasoner
(aka “rules engine”) will apply inherent
and specified rules to infer new facts (as triples) from a given
set of asserted triples.
▼
OpenSource
: OWLIM, Pellet
▼
Commercial:
RacerPro
,
OntoBroker
9
Ontology Documentation Tools
Ontology documentation tools will parse an ontology file
and produce formatted documentation generally in HTML
or PDF form.
▼
Open Source: Neologism
▼
Commercial: UISPIN
10
Web Development Kits
Web development kits for RDF datasets and ontology
provide dynamic interfaces to a
triplestore
to facilitate
search and exploration of RDF content.
▼
Open Source: Open Semantic Framework
Leveraging existing (non
-
RDF) data
Day 3
-
Basics
12
Overview
▼
Mapping relational data to RDF using D2RQ
▼
Mapping Excel Documents to RDF
▼
Mapping
XML to RDF/OWL
▼
Other Mappings (JSON, UML, Java/EMF Objects)
13
Mapping relational data to RDF using D2RQ
▼
Problem Description
▼
Custom Importers
▼
The D2RQ Approach
▼
Related Mappers
▼
Mapping SPARQL to SQL
14
Mapping Excel Documents to
RDF
▼
Similar to the RDBMS conversion problem.
▼
Spreadsheets lend themselves to complex tabular
structures.
▼
Schema and data can appear anywhere.
▼
One sheet may have any number of independent
tables.
▼
Meaning given to style. I.E. bold, italic, font color or
cell color may encode meaning.
▼
Multiple cells and formulas.
15
Mapping XML to RDF/OWL
▼
The XML Data Model
▼
Mapping Between Data Models
Finding Meaning between XML Nodes
▼
Custom Conversion
▼
Tools and Toolkits
16
Mapping XML to RDF/OWL
Differences in XML
•
The XML model is a tree structure.
•
XML provides structure to a document.
•
The XML utility is data packaging for transmission as
messages.
•
Uses schema for conformance validation.
•
Provides a standard that allows parsers to interpret
any XML document.
17
Other Mappings
▼
Converting JSON
▼
Importing UML
▼
Importing EMF Objects
18
Sample Applications
19
Design time applications
20
▼
Completed Work on
Weather
Integrated Surveillance
▼
Started Work on
Unmanned Aircraft System
Flight and Flow
▼
Key Deliverables
COI Ontology
Business Context (DoDAF Artifacts)
Other Artifacts
▼
Consistent with DoD Net
-
Centric Data Strategy
Process for Inter
-
Agency Shared Understanding
Service Description
(WSDL)
Message Schema
(XSD)
Transformation Rules
(XSLT)
Business Process
Analysis
(OV
-
2)
Systems Communications
Description
(SV
-
2)
Operational Activity
Model
(OV
-
5b)
Requirements Document
(SV
-
4)
Architectural Impact
Report
Business Rules
Service Constraints
Information Exchange
Description
(OV
-
3)
COI Ontology
(RDF/OWL)
21
▼
Purpose:
To be a collaborative web application through which users can publish, access,
search, browse, map, and update
ontologies
and their terms.
Reference Implementation only
▼
Supports:
COI participants (e.g.,
ontologists
, SMEs, and enterprise architects), developers
and managers
.
Ontology Portals
National Center for
Biomedical Ontology
BioPortal
Marine Metadata
Interoperability Ontology
Registry and Repository
Air Force Vocabulary
OneSource
Open Biomedical
Ontologies
Foundry
Example Portals
22
Semantic Metadata Catalog and Portal
Weather
Community
Integrated
Surveillance
Community
JPDO User Interface
Layer
Semantic
Metadata
Portal
External
Systems
GIIEP
SWIM
Semantic Processing
Layer
Artifact
Catalog
Existing
SOA
Registry
ebXML
UDDI
Web Services Layer
Service
Registration
and Discovery
Access
Semantic Metadata Catalog and Portal Architecture
Semantic
Metadata
Catalog
Semantic
External
Color Key:
Future
Service
Registration
and Discovery
Integration
of
Federated
Registry
NextGen
Ontology
Community
Ontology
Portal
Integration Layer
23
Sample Ontology Portals
▼
NCBO
BioPortal
http://bioportal.bioontology.org/
▼
One Source
http://onesource.afc2ic.org/
▼
Marine Metadata
Interoperabiligy
(MMI) Ontology
Registry and Repository (ORR)
▼
http://mmisw.org/
24
Run time application
25
SMB Approach: Semantics to Solutions
SOA
Foundation for Service Interoperability
Semantics
Common Understanding of Business Concepts
Problems
•
How I can improve Interoperability between different services
and reduce system integration costs?
•
I have already invested a lot in my SOA infrastructure, how
do
I leverage it for for Semantic
Interoperability?
•
How can Semantics help reduce service development cost
and help my enterprise operations?
Semantics
Mediation Bus™
Runtime
infrastructure
enables semantic
interoperability through
common ontologies
, even
if the
services are implemented using different
data models and message
standards.
26
SOA: Benefits and Limitations
•
Service Oriented Architecture (SOA)
•
Key Benefits:
−
Provides standards based mechanism to access Services at the transport and protocol level
−
Promotes re
-
use of existing services
−
Enables fast adaptation to business needs
−
Aligns information resources to business goals
•
Limitations:
−
Current Web Service standards provide the syntactic description of the service interface, but do not
describe the meaning or the semantics of the data or behavior. Hence the consumer of the service;
whether another service or a human, needs to have intimate knowledge and awareness about the data
and its elements
−
Current Enterprise Service Buses (ESBs) don’t have an out of the box ability to perform Semantic
Mediation, that is the transformation and co
-
relation of data elements and services based on a pre
-
defined vocabulary
−
Manual intervention and deep domain knowledge is required to develop custom mappings to correctly
use data exposed by these related but different Web Services
27
Service Consumer
FAA
Demo: Traditional SOA
Original
Track Data
Provider
Google Earth
Client
28
SOA Silos
SLIDE
28
Excess time is spent interpreting data from different sources despite the
usage of advanced IT techniques like Web Services
FAA Flight
Track Web
Service
AF Flight
Track
Web
Service
HR
Army
HR
Marine
Other
Data
Provider
User
Field Name:
Commercial Flight
Data
:
122
Airline Code Lookup Table
Data:
UA
Field Name
:
Flight of
Interest
Data:
United 122
Field Name:
FlightID
Data:
UA122
Flight
Track
Display
Reference
Developer
SME
AF SME
1
1
Human Communication
Custom
Mapping
Custom
Mapping
2
2
Custom
Development
3
3
System Integration
29
Problem with Custom
Development
▼
Discovery of Relevant Information
▼
Human in the Loop for Interoperability Assessment
▼
Custom Mapping and Custom Development
Often requires significant resources and takes a long time
▼
Change Management
Transformation often embed in code
Code and ontology could become disconnected
30
Service Consumer
FAA
Demo: SOA Silo
Original
Track Data
Provider
Google Earth
Client
Air Force
Alternate
Track Data
Provider
31
SOA
Infrastructure
Service Consumer
FAA
Demo: Semantic Service Provisioning
Original
Track Data
Provider
Google Earth
Client
Air Force
Alternate
Track Data
Provider
Semantic
Metadata
Catalog
Annotation
Discover
32
Benefits of Semantic Service Provisioning
▼
Discovery of Relevant Information
Beyond traditional keyword search
▼
No Need for Human in the Loop for Interoperability Assessment
Machine readable ontologies describe relationships among concept
▼
Avoid Custom Mapping and Custom Development
Faster Development Lifecycle
Reduced Development Cost
▼
Built for Change
Allow transformations and business rules to be managed independent of
the code
Consistent with Model Driven Architecture principals
33
Data
Open Standard Compliance
▼
Web Ontology Language (OWL)
▼
Semantic Annotations for WSDL and XML Schema (SAWSDL)
▼
Minimal Service Model (MSM
) and WSMO
-
Lite
▼
Extensible
Stylesheet
Language
Transformations (
XSLT
)
▼
Web Service Definition Language (WSDL
)
XML
URI
XSLT
Services
WSDL
REST
Semantics
OWL
WSMO
-
Lite
SAWSDL
SOAP
34
Minimal Service Model
Source:
http://cms
-
wg.sti2.org/minimal
-
service
-
model/
Service Ontology
Semantic Annotations for WSDL and
XML Schema (SAWSDL
)
•
Relate the Service and Message description to the meaning captured in an Ontology.
–
Annotations can be applied to all WSDL elements and XML Schema types.
•
Define transformation between wired message format and the ontology
representation.
SLIDE
35
WSDL
XML
Schema
Import
<
xsd:
ComplexType
name=“
FlightTrack
”
sawsdl:modelReference
=“… …”
sawsdl:liftingSchemaMapping
=“…”
sawsdl:loweringSchemaMapping
=“…”>
<operation
name=“
getFlightTrack
”
sawsdl:modelReference
=“… …”>
<input
message=”…”>
Enterprise
Vocabulary
ont:AirTrack
a
rdfs:Class
… …
svc:airTrackProvider
svc:payload
ont:AirTrack
… …
SPARQL+XSLT
XSLT
36
Alion Semantic Mediation Bus™
•
An ontology
-
based web services mediation component (Semantic Mediator) that enables
services with different message formats to interoperate
•
Embedding the Semantic Mediator in an Enterprise Service Bus (ESB) enables runtime
semantic mediation within traditional SOA infrastructure, creating a Semantic Mediation
Bus
TM
Enterprise Service Bus
Registry/ Repository
Traditional SOA infrastructure
Semantic Mediation
Infrastructure
Semantic Mediator
Protocol
Adaption
Message
Transformation
Message
Routing
Security
Service Discovery
Semantic Lookup and
Interoperability
Assessment
Message
Schema Mapping
Semantic
Annotation
Metadata
Management
Web Service Proxy
Common
Ontology
Semantic Mediation
Bus
TM
37
Semantic Mediation:
HR
Army
FAA
Web
Service
Air Force
Web
Service
HR
Army
HR
Marine
3
rd
Party
Web
Service
User
Semantic
Mediation
Bus™
Semantic Lookup
Field Name:
Commercial Flight
Data
:
211
Airline Code Lookup Table
Data:
UA
Field Name:
Flight of
Interest
Data:
UA211
Field Name:
FlightID
Data:
United 211
Common
Air
Track Ontology
Message
Transformation
Web Service
Endpoint
Flight
Track
Display
Reference
Dynamically Map Information to User Needs
38
Demo: Semantic Service Mediation
SOA
Infrastructure
Service Consumer
FAA
Original
Track Data
Provider
Google Earth
Client
Air Force
Alternate
Track Data
Provider
Semantic
Metadata
Catalog
Annotation
Semantic Discovery
Interoperability Assessment
Alion Semantic
Mediation Bus™
Message
Transformation
Dynamic
Service
Endpoint
39
Key Characteristics
▼
Cooperation
through federation, instead of
standardization
The
ontology driven approach avoids imposing a standard that has to be agreed by
everybody, thus allowing the agencies to select the formats best suited for their
business needs, while still being able to use services offered by other agencies.
▼
Increased
ability to adapt to the ever changing business needs in a timely
and cost effective
manner
The
semantic mediation approach encourages transformation logic to be
declaratively defined in the ontology, instead of buried in the code, often in multiple
places.
▼
No
need for rigid
conformance
Through
loose coupling, the SMB allows transformation between message formats
which might not be a complete match.
▼
Building
on SOA infrastructure, instead of replacing
it
By
extending ESB infrastructure, organization can leverage their SOA investment
and the existing expertise of their personnel.
40
Extensibility Considerations
▼
Pluggable to SOA Platforms
Integrate with existing Enterprise Service Buses (ESB)
Interact with Service Registry (
ebXML
, UDDI, proprietary)
▼
Adaptable to Service Design Choices
Mediate SOAP
-
based Web Services
Support REST and Plain XML Data
Service Metadata
▼
Provide Intelligent Mediation
Assess service compatibilities based on semantics
41
Technical Architecture
Enterprise Service Bus
Semantic
Mediation
Bus
Service
Endpoint
Service
Endpoint
Registry/Repository
OWL Ontology
XML
Schema
SAWSDL
Annotation
Web
Service
Aggregation Proxy
Semantic Lookup
XML
Schema
WSDL
WSDL
SAWSDL
Annotation
Lifting and
Lowering Rules
Lifting and
Lowering Rules
Service Consumer
Service Provider
Service Consumer cannot
process the WSDL as
implemented by the provider
Mediation Engine
is implemented as
component of the
ESB.
However, the WSDL
messages can be traced to an
ontology understood by the
consumer.
Initial implementation uses
SAWSDL lifting and
lowering
rules,
which
define how XML messages
are transformed to and created from
an ontology
The engine
dynamically
exposes
a web service
endpoint as a proxy
to the service. The
endpoint expose
a
WSDL
that
can be
accepted by the
consumer
Extension Framework
XML/WSDL
-
OWL
Mapping
Interoperability
Assessment Algorithm
ESB Adapter
ESB
API
Extension
API
Message
Transformation
Service
Endpoint
The service proxy
may aggregate
service from
multiple providers
based on the
need of
consumer.
Traditional SOA
infrastructure
Semantic Mediation
Infrastructure
42
Building Block for Enterprise Solutions
▼
Enterprise
Challenge: Data integration is as much an issue as in
the inter
-
organizational context
Data
mash up
solution from disparate systems
I
ncorporation
of unanticipated sources in
business intelligence
E
nhancement
of
situational
awareness through on
-
demand integration of
data
▼
Opportunity: Ontology is not only a tool for understanding, but also
a basis for executable solutions
43
The SMB Message
▼
Put Ontologies to Work
Enhance service understandability at design time
Facilitate service interoperability at runtime
▼
Leverage Existing SOA Investment
Increase service discoverability and interoperability through semantic
annotation
Build on existing services
Use in
-
house expertise
Ready to deployed now
▼
Streamline Service Integration
Shorten development lifecycle by eliminating the need for custom message
mapping
Reduce maintenance cost by leveraging existing infrastructure
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