=Paper=
{{Paper
|id=None
|storemode=property
|title=Semantic Interoperability Framework for Estonian Public Sector's E-Services Integration
|pdfUrl=https://ceur-ws.org/Vol-596/paper-13.pdf
|volume=Vol-596
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==Semantic Interoperability Framework for Estonian Public Sector's E-Services Integration==
https://ceur-ws.org/Vol-596/paper-13.pdf
Vol-596
urn:nbn:de:0074-596-3
C opyright © 2010 for the individual
papers by the papers' authors.
C opying permitted only for private and
academic purposes. This volume is
published and copyrighted by its
editors.
ORES-2010
Ontology Repositories and Editors for
the Semantic Web
Proceedings of the 1st Workshop on Ontology Repositories and
Editors for the Semantic Web
Hersonissos, Crete, Greece, May 31st, 2010.
Edited by
Mathieu d'Aquin, The Open University, UK
Alexander García Castro, Universität Bremen, Germany
Christoph Lange, Jacobs University Bremen, Germany
Kim Viljanen, Aalto University, Helsinki, Finland
10-Jun-2010: submitted by C hristoph Lange
11-Jun-2010: published on C EUR-WS.org
Semantic Interoperability Framework for Estonian
Public Sector’s E-Services Integration∗
Kalle Tomingas1 , Martin Luts2,3
1
Department of Computer Science, Tallinn University of Technology, Estonia,
2
Department of Informatics, Tallinn University of Technology, Estonia
3
ELIKO Competence Centre in Electronics-, Info- and Communication Technologies, Tallinn, Estonia
June 10, 2010
Abstract
E-services, based on automated data exchange in distributed technological and
organizational environment, are an effective way to build cross-border, controlled
information services. Processes of creation, integration, management, reuse, dis-
covery and composition of e-services are not very efficient without understand-
ing the meaning of information resources. Creation and management of human
and machine readable semantics of heterogeneous and distributed information
resources are more complicated than coordinated documentation process, and
require new interoperability principles, architecture and infrastructure. This pa-
per outlines the idea and architecture of the Estonian semantic interoperability
initiative in the public sector. The paper presents a collaborative ontology engi-
neering toolset and repository as a part of interoperability infrastructure, built
with Semantic Mediawiki, to manage the semantics of information resources.
Keywords: semantic interoperability, ontology, web service, web service anno-
tation, semantic mediawiki, rdf/rdfs, owl, wsdl/sa-wsdl.
1 Introduction
This paper describes the Estonian public sector’s semantic interoperability initiative
and outlines the architecture of semantic integration of State Information Systems
and e-services. The paper provides a framework, a toolset and a collaborative se-
mantic assets management solution in the Semantic Mediawiki1 (SMW) environment.
We concentrate on the practical implementation of infoware metadata management
like web services descriptions, ontologies, classifiers, their creation, import and export,
versioning, collaboration and change management. The paper shows how annotation
and linking of different assets allows us to realize the semantic interoperability idea,
manage the heterogeneous information resources and give them human and machine
readable semantics. The given semantics is used for search, mange and re-use of exist-
ing information assets components, quality insurance, new web services discovery and
composition.
Examples of semantic interoperability initiatives can be found in different EU coun-
tries: UK Public Sector Linked Data Government 2 , Germany’s Deutschland Online3 ,
∗ This research was supported by European Social Fund’s Doctoral Studies and Internationalisation
Programme DoRa
1 http://semantic-mediawiki.org
2 http://data.gov.uk/
3 http://www.deutschland-online.de/DOL_en_Internet/broker.jsp
1
Italian Public Administration4 , Finnish FinnONTO5 [2], Estonian Semantic Interop-
erability Framework [1] or Latvian’s Semantic Latvia [3]. Ideas behind those projects
vary from human readable semantic descriptions to a large-scale international semantic
interoperability infrastructure. Other examples about Pan-European semantic inter-
operability initiatives are SEMIC (SEMantic Interoperability Centre Europe)6 , led by
the European Commission’s ISA7 program and SemanticGov8 , which is targeted to
provide integrated public services to citizens at the national or Pan-European level [4].
SEMIC is designed as a brokerage platform for existing third party semantic assets
(e.g. classification lists, ontologies, etc.). The aim of SemanticGov is to build the new
infrastructure (software, models, services, etc.) necessary for enabling the offering of
semantic web services for public administration agencies, within and between the EU
countries.
2 Semantic Interoperability Architecture
The semantic interoperability architecture for state information system and registries of
Estonia (see Figure 1) consists of the following interrelated components: ontologies and
semantically annotated objects supported by policies and guidelines, several processes
and workflows, tools, educational activities, PR among others. The Administration
System for the State Information System [5]and Semantic Asset Management Envi-
ronment (SEHKE) are the central tools in the semantic interoperability architecture
for the state information system. SEHKE fulfills the following tasks in the semantic
interoperability architecture: hosting and publishing of ontologies, infoware’s metadata
including semantic annotations; serving as a semantic search engine for semantic assets
(resources).
SEHKE works to ensure the interoperability of public sector registries and the reuse
of technical, organizational and semantic resources. For end-users, SEHKE is the tool
for obtaining information about existing services (as well as about service descriptions
and the principles of service provision) and apply for the right to use a service or
propose the creation of a new service.
One of the main components of the semantic interoperability architecture – as de-
signed for Estonian state registries – is ontology. We use the term ‘ontology’ meaning
“a formal explicit specification of a shared conceptualization for a domain of interest”
[6] and “information about how individuals are grouped and fit together in a partic-
ular domain”. Currently, there are some ontologies in Estonian, which could be used
to annotate operations performed by state registries and other objects. The ontology
component in our architectural framework is not a monolithic structure – for the pur-
poses of easier, domain-expert driven maintenance, it is divided into subject areas or
domains, e.g. “Environment”, “Social Affairs”. The initial tree for categorizing ontolo-
gies is based on the official naming of EU activities. The language used in the semantic
description of ontology objects draws from W3C recommendation OWL (Web Ontol-
ogy Language)9 . Ontologies are developed and maintained in a distributed manner,
but stored and published centrally. The tools to be used for ontology maintenance are
not prescribed as long as certain standards are followed (e.g. Collaborative Protégé,
Semantic Mediawiki or others). In the next section, we give an overview of a new online
collaborative tool for semantic resources management, which is playing an important
4 http://www.cnipa.gov.it/site/it-IT/
5 http://www.seco.tkk.fi/projects/finnonto/
6 http://semic.eu/about_semantic_interoperability_centre_europe.html
7 http://ec.europa.eu/isa
8 http://www.semantic-gov.org/
9 http://www.w3.org/TR/2004/REC-owl-features-20040210
2
Figure 1: Semantic interoperability conceptual architecture for state information sys-
tem and registries
part in the large-scale semantic interoperability initiative.
3 Collaborative Semantic Resource Management
SEHKE is a web-based collaborative environment for creating, management and an-
notation of semantic resources and assets of state information systems and registries..
SEHKE is built to handle information resources like ontologies, concepts and proper-
ties, subject areas (domains of interests), web service descriptions and classifications.
SEHKE environment is one piece in the big picture of large-scale semantic interop-
erability architecture. The functionality of the SEHKE toolset covers the creation
process of the information assets (e.g. ontologies, web service descriptions, classifiers),
the semantic annotation of web service descriptions, collaboration, responsibility, noti-
fications and approval, quality and version control, import and export, semantic search
and finally (re)usage of all assets. The SEHKE environment is set up and implemented
in the Semantic Mediawiki environment, where the needed functionality is built with
semantic extensions, templates and forms, existing plugins and new developed compo-
nents for special requirements (import and export).
System concepts of the SEHKE environment are based on the main categories of
semantic assets. System concepts are implemented as wiki pages, with certain types
of mandatory properties and a set of defined forms, to create and manage a content
of different concept types. One required property is “Type”, which is the main in-
strument to categorize concepts (e.g. [[Type::Ontology]]). Each SEHKE concept has
its own set of required or allowed properties that are used to implement the possi-
ble relationships between different system concepts (e.g. ontology page has property
[[SubjectArea::Economy]] to define a relation that the ontology belongs to the sub-
ject area). Named and implemented properties and their values form the schema of
concepts (Figure 2) that represents the semantic interoperability requirements and the
structure of SEHKE functionality.
Ontology is one of the key concepts of the SEHKE tool and it stands for formal-
ized semantics. Ontology is a named set of concepts, their definitions, hierarchies and
properties that represents the conceptualization of the domain or subject area, which
3
Figure 2: Schema of system concepts of SEHKE environment
is in the interest of the Estonian public sector. Ontology and its concepts are besides
web services descriptions and classifications a main type of semantic assets. Ontology
belongs to the subject area that frames the domain and the responsibility of the owner
of the ontology. Ontology is implemented as a special page, with the idea to group
and collect related classes, their properties, instances and rules. Ontology, its member
concepts and properties (data and object properties) can have multiple terms (set of
names and descriptions) in different languages, which explain the meaning of the item.
Concepts (classes) are organized into taxonomies or hierarchies (e.g. using property
definition [[subclassOf::ParentConceptName]] to associate concept page with a higher
level concept), and they can have certain formalization rules that can be automatically
checked and validated by automatic reasoning programs. The creation of ontologies,
concepts and properties is simplified through automated detection of similar assets,
supported by syntactic and semantic search algorithms and backed with the different
language techniques. Ontology creation and management has online collaborative sup-
port functions, like email notifications, change acceptance and an iterative process for
achieving consensus between multiple parties. The collection of all SEHKE pages forms
the general wiki namespace (e.g. http://www.sehke.eu/ is the namespace of public in-
stance of the SEHKE environment). In addition to the wiki’s namespace, ontology has
special “Namespace” property (e.g. ), for different namespace values that are used in
ontology export/import to rdf/owl. The multiuser collaborative editing, multilingual
terms and descriptions and configurable language techniques makes the SEHKE a real
multi-national semantic tool.
WSDL is a SEHKE concept for web services descriptions that documents e-services
of the Estonian state information system’s data transportation layer X-Road (Estonian
X-Tee)10 . X-Road currently supports the technical interoperability of the components
of state information systems and registries and SEHKE is like an extension for adding
a semantic layer top of the X-Road infrastructure. Web services description documents
10 http://www.riso.ee/en/information-policy/projects/x-road
4
are semantic assets, which can be imported and exported in WSDL/SA-WSDL11 lan-
guage. The essential idea of semantic interoperability is to add semantic annotations
to web services input/output data elements and structures and related operations. De-
fined ontology’s concepts and data or object properties are the key ideas that are used
for WSDL annotations. An annotation is a semantic relationship between a WSDL ele-
ment and an ontology’s concept, which can be created manually or semi-automatically
(in the future releases), using syntactic and semantic search algorithms, to match sim-
ilar terms with the concepts (e.g. SAWSDL modelReference extension attribute used
to associate WSDL elements with a semantic model). Semantic annotation of web
services brings us to the next level, which makes available automatic discovery of web
services and composition of new web services. The composition of new services is based
on existing services, operations and their input/output data elements, which have a
semantic match on the conceptual level.
4 Conclusions
The main approach to extend semantic interoperability in communication and informa-
tion exchange process is to build a higher semantic integration layer on top of participat-
ing information systems and organizations. Mapping critical communication structures
against ontologies and the same semantic concepts using annotation techniques adds
human- and machine-readable semantics to the process. Opening the meaning of sys-
tem components and functions, integrating computer programs, linguistic techniques
and human touch to knowledge management process, we fulfill the promises and ex-
pectations of semantic interoperability idea and creating better public sectors services.
The SEHKE toolset that is powered with semantic functionality of the SMW is the
open platform for collaboration and semantic asset management (e.g. ontologies) and
meant to be part of federated pan-European repository initiative: SEMIC.EU [7].
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5