@inproceedings{2857, author = {{Mohr, Felix and Lettmann, Theodor and Hüllermeier, Eyke and Wever, Marcel Dominik}}, booktitle = {{Proceedings of the 1st ICAPS Workshop on Hierarchical Planning}}, location = {{Delft, Netherlands}}, pages = {{31--39}}, publisher = {{AAAI}}, title = {{{Programmatic Task Network Planning}}}, year = {{2018}}, } @inproceedings{115, abstract = {{Whenever customers have to decide between different instances of the same product, they are interested in buying the best product. In contrast, companies are interested in reducing the construction effort (and usually as a consequence thereof, the quality) to gain profit. The described setting is widely known as opposed preferences in quality of the product and also applies to the context of service-oriented computing. In general, service-oriented computing emphasizes the construction of large software systems out of existing services, where services are small and self-contained pieces of software that adhere to a specified interface. Several implementations of the same interface are considered as several instances of the same service. Thereby, customers are interested in buying the best service implementation for their service composition wrt. to metrics, such as costs, energy, memory consumption, or execution time. One way to ensure the service quality is to employ certificates, which can come in different kinds: Technical certificates proving correctness can be automatically constructed by the service provider and again be automatically checked by the user. Digital certificates allow proof of the integrity of a product. Other certificates might be rolled out if service providers follow a good software construction principle, which is checked in annual audits. Whereas all of these certificates are handled differently in service markets, what they have in common is that they influence the buying decisions of customers. In this paper, we review state-of-the-art developments in certification with respect to service-oriented computing. We not only discuss how certificates are constructed and handled in service-oriented computing but also review the effects of certificates on the market from an economic perspective.}}, author = {{Jakobs, Marie-Christine and Krämer, Julia and van Straaten, Dirk and Lettmann, Theodor}}, booktitle = {{The Ninth International Conferences on Advanced Service Computing (SERVICE COMPUTATION)}}, editor = {{Marcelo De Barros, Janusz Klink,Tadeus Uhl, Thomas Prinz}}, pages = {{7--12}}, title = {{{Certification Matters for Service Markets}}}, year = {{2017}}, } @inproceedings{10206, author = {{Mohr, Felix and Lettmann, Theodor and Hüllermeier, Eyke}}, booktitle = {{Proc. 40th Annual German Conference on Advances in Artificial Intelligence (KI 2017)}}, pages = {{193--206}}, title = {{{Planning with Independent Task Networks}}}, doi = {{10.1007/978-3-319-67190-1_15}}, year = {{2017}}, } @inproceedings{495, abstract = {{Automated service composition has been studied as a subject of state based planning for a decade. A great deal of service composition tasks can only be solved if concrete output values of the services are considered in the composition process. However, the fact that those values are not known before runtime leads to nondeterministic planning problems, which have proven to be notoriously difficult in practical automated service composition applications. Even though this problem is frequently recognized, it has still received remarkably few attention and remains unsolved.This paper shows how nondeterminism in automated service composition can be reduced. We introduce context rules as a means to derive semantic knowledge from output values of services. These rules enable us to replace nondeterministic composition operations by less nondeterministic or even completely deterministic ones. We show the validity of our solutions not only theoretically but also have evaluated them practically through implementation.}}, author = {{Mohr, Felix and Lettmann, Theodor and Kleine Büning, Hans}}, booktitle = {{Proceedings of the 6th International Conference on Service Oriented Computing and Applications (SOCA)}}, pages = {{154--161}}, title = {{{Reducing Nondeterminism in Automated Service Composition}}}, doi = {{10.1109/SOCA.2013.25}}, year = {{2013}}, } @article{3332, author = {{Lettmann, Theodor and Baumann, Michael and Eberling, Markus and Kemmerich, Thomas}}, isbn = {{9783642240157}}, issn = {{0302-9743}}, journal = {{Transactions on Computational Collective Intelligence V}}, pages = {{157--181}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Modeling Agents and Agent Systems}}}, doi = {{10.1007/978-3-642-24016-4_9}}, year = {{2011}}, } @inproceedings{3327, author = {{Stein, Benno and Niggemann, Oliver and Lettmann, Theodor}}, booktitle = {{AIA '06: Proceedings of the 24th IASTED International Conference on Artificial Intelligence and Applications}}, pages = {{273----278}}, title = {{{Speeding Up Model-based Diagnosis by a Heuristic Approach to Solving SAT}}}, year = {{2006}}, } @article{19815, author = {{Kleine Büning, Hans and Lettmann, Theodor}}, issn = {{0166-218X}}, journal = {{Discrete Applied Mathematics}}, pages = {{139--148}}, title = {{{Resolution remains hard under equivalence}}}, doi = {{10.1016/s0166-218x(99)00055-4}}, year = {{1999}}, } @book{3339, author = {{Lettmann, Theodor and Kleine Büning, Hans}}, isbn = {{0521630177}}, publisher = {{Cambridge Univ. Press}}, title = {{{Propositional Logic : Deduction and Algorithms}}}, year = {{1999}}, } @inbook{19816, author = {{Kleine Büning, Hans and Lettmann, Theodor}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783540618638}}, issn = {{0302-9743}}, title = {{{Learning a representation for optimizable formulas}}}, doi = {{10.1007/3-540-61863-5_33}}, year = {{1996}}, } @book{3333, author = {{Kleine Büning, Hans and Lettmann, Theodor}}, isbn = {{978-3-519-02133-9}}, publisher = {{Teubner}}, title = {{{Aussagenlogik - Deduktion und Algorithmen}}}, doi = {{10.1007/978-3-322-84809-3}}, year = {{1994}}, } @article{19814, author = {{Flögel, A. and Kleine Büning, H. and Lettmann, Theodor}}, issn = {{0988-3754}}, journal = {{RAIRO - Theoretical Informatics and Applications}}, pages = {{327--340}}, title = {{{On the restricted equivalence for subclasses of propositional logic}}}, doi = {{10.1051/ita/1993270403271}}, year = {{1993}}, } @techreport{19822, author = {{Dahn, Bernd I. and Lettmann, Theodor and Schönfeld, Wolfgang}}, publisher = {{Wissenschaftliche Zentrum der IBM Deutschland }}, title = {{{ILFA Interface Concept}}}, volume = {{193}}, year = {{1991}}, } @article{19818, author = {{Kleine Büning, Hans and Lettmann, Theodor and Mayr, Ernst W.}}, issn = {{0304-3975}}, journal = {{Theoretical Computer Science}}, pages = {{343--350}}, title = {{{Projections of vector addition system reachability sets are semilinear}}}, doi = {{10.1016/0304-3975(89)90055-8}}, year = {{1989}}, } @inproceedings{19820, author = {{Kleine Büning, Hans and Lettmann, Theodor}}, booktitle = {{Workshop Wissensrepräsentation in Expertensystemen}}, editor = {{Rahmstorf, G.}}, isbn = {{9783540192169}}, issn = {{0343-3005}}, pages = {{56--78}}, title = {{{Perspektiven für die Logikprogrammierung}}}, year = {{1988}}, } @inbook{19821, author = {{Büning, Hans Kleine and Lettmann, Theodor}}, booktitle = {{Computation Theory and Logic}}, editor = {{Börger, Egon}}, isbn = {{9783540181705}}, issn = {{0302-9743}}, pages = {{208--223}}, title = {{{Representation independent query and update operations on propositional definite Horn formulas}}}, doi = {{10.1007/3-540-18170-9_167}}, year = {{1987}}, } @inbook{19819, author = {{Kleine Büning, H. and Lettmann, Theodor}}, booktitle = {{8th International Conference on Automated Deduction}}, isbn = {{9783540167808}}, issn = {{0302-9743}}, title = {{{Classes of first order formulas under various satisfiability definitions}}}, doi = {{10.1007/3-540-16780-3_119}}, year = {{1986}}, }