Semantic Interoperability in InteliGrid

Semantic Interoperabilityin InteliGrid

Ž. Turk and P. Katranuschkov

with input fromthe inteliGrid consortiumwww.inteliGrid.com

Semantic interoperability in context

• Business process are:• material and information

• Information processes include:• Value-adding activities• Communication activities / cooperation activities

• Communication and cooperation are possible when humans / software actors:

• can ‘talk’ to each other syntactic interoperability• can ‘understand’ each other semantic interoperability• can properly ‘respond’ to

changes in the environment knowledgeable interoperability

inteliGrid “stack”

• business process• dynamic VO

• semantics• schemas• conceptual models• ontologies

• technology• CORBA, DCOM• Web Services, .net• Grid

Part 1: BUSINESS PROCESS

60's60's

70's70's

80's80's

70's70's

Engineering Design

FEM

Prefabricatedcomponentmodelling

90's90's

StructuralStructuralanalysisanalysisStructuralStructuralanalysisanalysis

ParametricParametricdesigndesignParametricParametricdesigndesign

Great Information Barrier Reef

80's80's

90's90's

3D 3D visualizationvisualization 3D 3D visualizationvisualization

Building Use & Maintenance

FMFMFMFM

EDI

60's60's

70's70's

80's80's

90's90's

80's80'sConstruction

Production Planning

Production Automation

Accounting Accounting & data mgt& data mgtAccounting Accounting & data mgt& data mgt

Under construction:IFC GATE

Will be ready real soon now

PDMPDM

Product Product data data basesbases

Product Product data data basesbases

Architectural Design

QuantityQuantitycalculationcalculationQuantityQuantitycalculationcalculation

DXFferryInformation

brokers

CAD

Internet 2D 2D DraughtingDraughting 2D 2D DraughtingDraughting

VO Spanning Islands of Automation

Matti Hannus, VTT

Human Centred VO

ENGINEER 1

Project A

Project N

Project A

Engineer 1

Engineer n

project centered

user centeredR.J.Scherer, TUD

Dynamic VO

• need to go in and out of a VO fast• how?• if you carry your own

• not bring much luggage• small semantic footprint• files, documents• costs down the road

• if you have some help• lots of semantic luggage• big semantic footprint• objects• savings down the road

Part 2: SEMANTICS

Footnote on Semantics

• does this have meaning?

• how about this?• <name>ziga</name>• <firstName>turk</firstname>• <project>inteliGrid</project>

• it’s the same, just the font is different• so where is meaning?

I, too, am a line

location

dimensions

material

description

performance

characteristi

cs

quality

interrelation

ships

Structured vs. unstructured

traditional• unstructured• low-level semantic• document based• sequential work

modern• structured• high-level semantics• shared databases• distributed coordinated

teamwork

I’m a line

So am I

I’m a wall

I’m a window

Before ontology engineering: Conceptual product modeling

• NIAM• ISO 10303 Express, Express-g• UML• XML Schema• RDF Schema• DAML/OIL, OWL, OWL-S• ACL/KIF, KL1 family• ???

• … nodes and arcs

1980s Wall Concept (NIAM)

1990s WallExpress-G, Express

2000s Wall (XML)

...<Wall id="EoWall02"><Properties><name>EoWall02</name> <description>Wall instance based on the Engineering Ontology Definitions.</description> <material ref="EoMaterial01" /> <crossSectionType>rectangle</crossSectionType> <crossSectionParameters><parameter unit="{m}">0.3</parameter> <parameter unit="{m}">0.3</parameter>

</crossSectionParameters><length unit="{m}">2.8</length>

</Properties></Wall>...

The real problem

• not the current fashion of encoding the nodes and arches

• but what are the nodes and arches• what is a wall• what is the wing of an airplane• what is a keel of a ship

Continuous research efforts:

• C. K. Ogden (1923) The Meaning of Meaning• A. Tarski (1944) The Semantic Conception of Truth,

Philosophy and Phenomenological Research• A. Newell (1982) The Knowledge Level• C. Hewitt (1985) Open Systems• C. Eastman (1992) Modelling of Building: Evolution and

Concepts• T. Gruber (1993) Towards Principles of the Design of

Ontologies Used for Knowledge Sharing • J. Benjamin (1998) Ontology Construction in Technical

Domains

• footnote: but is the world really built out of objects with properties

The answer to the problem

• ISO DPAS 12006-2• Classification System

• ISO 10303 STEP• Standard for the Exchange of Product

Data • 103 classes• automotive, aerospace, shipbuilding

• ISO PAS 16739 IFC 2.x• Industry Foundation Classes• 103 classes• AEC

Software support

Part 3: TECHNOLOGY

ISO STEP reference architecture for manufacturing

Enterprise Product Model

Business Object

ProprietaryEnvironment

ProprietaryKnowledge

ProprietaryEnvironment

ProprietaryKnowledge

Requirements/feasibility

Design Simulation Manufacturing Product support

ProprietaryEnvironment

ProprietaryKnowledge

defines

Integrated schema Product model dataReference data library

Inte

r-d

iscip

lin

ary

collab

ora

tion

Intr

a-d

iscip

lin

ary

collab

ora

tion

PDM schema

Op

en

Data

S

tan

dard

s

ISO15926

Life-cycle

AP233 AP203e2 AP214 AP210 AP209 AP237 AP233 AP238 AP239

Business Object •Data completion•Methods•Data validation•Data conversion•Check-in/check-out•Versioning/history•Configurations•Origin/rights•Design Intent

Business Object

Enterprise Product ModelReference Data Library

Application

Aspect

Represents a subset of the

product model population e.g. transmission, door, wing,

landing gear, etc.

Represents a view of

the product model, e.g. structural, electrical,

etc.

Methods for accessing/updating

the underlying data contained in

the business object.

Rules

The meaning triangle interpreted

ConceptConceptRepositoryRepository

Proxy

representationreferenceD

esig

nati o

n

Den

otat

ion

TermsTerms contained in design/construction documents and in the heads of the designers – eng. knowledge (“site”, “building”, “storey” …)

Business objects (IFC product model dataBusiness objects (IFC product model data)) contained e.g. in CAD drawings(IfcSite, IfcBuilding, IfcBuildingStorey …)

IfcProject

IfcProcess

IfcProduct

IfcBuilding

IfcSite

IfcElement

IfcSpatialElement

IfcObject

IfcRoot

Real world objectsReal world objects

Fuzzy, ambiguous

Difficult to realise completely

Complex

Middleware Extensions – a possibility

ogsa-dai

ifo-oi

The Ontology Layer Suggested in inteliGrid

• Provide an ontology-committed view to grid information and services

• Ontology used as formal, explicit specification of a shared conceptualisation

- formal ontology should be machine readable- explicit explicit definition of concept types and

constraints - shared used to define a common standard in the

domain• Needed for improvements in

- data/service discovery- data/service integration (for disparate sources)- data/service quality improvement (management of consistency)- flexibility and maintainability of the grid- IFC based semantic interoperability through I-OWL- possibly ontology-enabled user interfaces

intelligent semantic interoperabilityintelligent semantic interoperability

OGSA-DAI

Product Data and Ontology Framework

OWL(RDF/XSD/XML)

ontology tools-editors-parsers

-reasoners-servers

generic ontology specifications

(generic definitions/specifications)

AEC specificontology

(ifcOWL)

ifcXML

databases

IFC / ISOstandard product

data models

engineering applications

(application access)

defined

by

specializationof

ontologydef.

dataaccess

guidedby

guided

by

product

servers

existing

tools

(CAD,etc.)

Ontology Augmented Data Access Scenario

Information request by client Interpret information need Request list of available information Transform information request Retrieve & transform model based info Fill A-box based with available information Specify required information resources Request information resources Deliver information resources offer information to client

Ontology Information Logistic

InfoServer I

InfoServer II

InfoServer III

Ontology Server

Taxonomy

Assertions

…Basic AssertionsWhat resources, where

Geometry view

Ontology-Enabled GUI

Challenges

Challenges: Research, Development, Migration

• can grids compete with web services as interoperability platform? what are the advantages, disadvantages? Is WSRF the right solution?

• ontology committed semantics not one service of the grid but a feature of the grid as a whole

• what kind of ontology?• lean or fat,• one – hardwired, one – exchangeable• for documents or for objects• several competing ontologies

Challenges: Research, Development, Migration

• grid toolkits are de-facto “distributed processing job” biased

• immaturity of the technologies: OGSI, WSRF, what’s next?

Challenges: Research, Development, Migration

• business model: one AEC grid with several project Web/portal providers or one grid or portals evolve to grids?

• does this work for software developers and service providers, how can they be motivated for grid-based solutions

• does this simplify the IT access for an VO

The end