Policy based contracting in semantic web service markets [Elektronische Ressource] / by Steffen Lamparter

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• Publié par: karlsruher_institut_fur_technologie
• Publié le: 01 janvier 2007
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 3 Mo

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Steffen Lamparter
Policy-based Contracting in Semantic Web Service MarketsStudies on eOrganisation and Market Engineering 7
Universität Karlsruhe (TH)
Herausgeber:
Prof. Dr. Christof Weinhardt. Thomas Dreier
Prof. Dr. Rudi StuderPolicy-based Contracting in
Semantic Web Service Markets
by
Steffen LamparterDissertation, genehmigt von der Fakultät für Wirtschaftswissenschaften
der Universität Fridericiana zu Karlsruhe, 2007
Referenten: Prof. Dr. Rudi Studer
. Christof Weinhardt
Impressum
Universitätsverlag Karlsruhe
c/o Universitätsbibliothek
Straße am Forum 2
D-76131 Karlsruhe
www.uvka.de
Dieses Werk ist unter folgender Creative Commons-Lizenz
lizenziert: http://creativecommons.org/licenses/by-nc-nd/2.0/de/
Universitätsverlag Karlsruhe 2007
Print on Demand
ISSN: 1862-8893
ISBN: 978-3-86644-181-1Abstract
Web services generalize the idea of the Web beyond the exchange of simple Web
pagesinordertoenabletheprovisionofabroadrangeofdifferentservices. Bycom-
posing Webservices, cross-organizational and collaborative business processes can
berealizedinahighlydynamic andflexibleway,which is particularlyimportant if
serviceshavetobeautomaticallyprocuredatruntime. However,achievingahigher
degree of automation is obstructed by the informal nature of legal, contractual and
organizational regulations, the numerous and complexservice descriptions includ-
ingmanifoldcustomizationpossibilities,andtheopenandheterogeneousnatureof
theWebservicemarket.
In this thesis, semantic technologies that provide more explicit meaning of in-
formation are employed to address these problems. These technologies facilitate
the exchange of information in heterogeneous systems and increase the share of
machine-understandabledataaccessible forautomated decision-making. Weintro-
ducetheCorePolicyOntologyinordertocaptureregulationsaswellaspreferences
by means of goal and utility function policies, respectively. Furthermore, we in-
troduce the Core Ontology of Bids that facilitates customization of Web services to
specific user needs by efficiently representing highly configurable Web service of-
fers and requests. Analogously, we derive the Core Contract Ontology from the
CorePolicyOntologytoformallyrepresentWebservicecontracts. Thereby,wepro-
vide an open, transparent and interoperable representation of contracts and enable
a tight integration of contractual information with the collaborative business inter-
actionstheygovern.
In order to show the applicability of the presented ontologies, we introduce an
automated contracting mechanism that includes algorithms for automated match-
ing,allocation,contractformation andcontractmonitoring. Itexploitsthesemantic
descriptions provided by the ontology framework and thereby enables logic-based
matchingbetweenoffersandrequestsandthespecification ofpoliciesonhierarchi-
cal sets of service characteristics. Since declarative matching and allocation rules
are used to define the mechanism, it can be dynamically adapted to new domains
or settings. For the efficient allocation of Web services in heterogeneous environ-
ments,wepresentanovelapproachthatenablestheintegrationofsemanticmatch-
ing and efficient optimization techniques such as linear programming. Moreover,
the mechanism can be used to verify whether a Web service invocation adheres to
the obligations stated in the contract. The contracting mechanism is prototypically
implemented using WS-BPEL and the ontology reasoner KAON2. The evaluation
oftheprototype indicates thatWebservicecontracting is applicableinpracticeand
that semantic matching of requests and offers is particularly important for settings
withhighlycustomizableservices.viAcknowledgements
This work would not have been possible without the support and guidance of
many persons. First of all, I would like to thank my advisor Professor Dr. Rudi
Studer for giving me the opportunity to do this research. Throughout my studies
hegrantedmethefreedom,thetrust,andthehelpIneeded.
In addition, I would like to thank my co-advisor Professor Dr. Christof Wein-
hardt for fostering my interdisciplinary research by providing new ideas and
insights. Thanks also to the other committee members, Professor Dr. Wolffried
StuckyandProfessorDr.HagenLindstädt,fortheirsupport.
I would like to thank the phenomenal team at the research group LS3WIM and
the graduate school IME. They provided the inspiration and constructive criticism
that helped me to continuously improve my work. In particular, I am grateful
to Anupriya Ankolekar, Sudhir Agarwal, and Andreas Eberhart for guiding my
research and for many fruitful discussions and debates. Special thanks also to
Saartje Brockmans, Björn Schnizler, Julien Tane, and Raphael Volz who took the
timetoreviewchaptersofthisbookandprovidedmewithinvaluablecomments.
Above all, I am indebted to my family and friends. This work would not have
beenpossiblewithout alltheirsupport, encouragement, andconfidenceduringmy
PhDstudyandespeciallyduringwritingofthisthesis.
SteffenLamparterviii