@article{GebserSchaubThieleetal.2011, author = {Gebser, Martin and Schaub, Torsten and Thiele, Sven and Veber, Philippe}, title = {Detecting inconsistencies in large biological networks with answer set programming}, series = {Theory and practice of logic programming}, volume = {11}, journal = {Theory and practice of logic programming}, number = {5-6}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {1471-0684}, doi = {10.1017/S1471068410000554}, pages = {323 -- 360}, year = {2011}, abstract = {We introduce an approach to detecting inconsistencies in large biological networks by using answer set programming. To this end, we build upon a recently proposed notion of consistency between biochemical/genetic reactions and high-throughput profiles of cell activity. We then present an approach based on answer set programming to check the consistency of large-scale data sets. Moreover, we extend this methodology to provide explanations for inconsistencies by determining minimal representations of conflicts. In practice, this can be used to identify unreliable data or to indicate missing reactions.}, language = {en} } @article{GebserKaminskiSchaub2011, author = {Gebser, Martin and Kaminski, Roland and Schaub, Torsten}, title = {Complex optimization in answer set programming}, series = {Theory and practice of logic programming}, volume = {11}, journal = {Theory and practice of logic programming}, number = {3}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {1471-0684}, doi = {10.1017/S1471068411000329}, pages = {821 -- 839}, year = {2011}, abstract = {Preference handling and optimization are indispensable means for addressing nontrivial applications in Answer Set Programming (ASP). However, their implementation becomes difficult whenever they bring about a significant increase in computational complexity. As a consequence, existing ASP systems do not offer complex optimization capacities, supporting, for instance, inclusion-based minimization or Pareto efficiency. Rather, such complex criteria are typically addressed by resorting to dedicated modeling techniques, like saturation. Unlike the ease of common ASP modeling, however, these techniques are rather involved and hardly usable by ASP laymen. We address this problem by developing a general implementation technique by means of meta-prpogramming, thus reusing existing ASP systems to capture various forms of qualitative preferences among answer sets. In this way, complex preferences and optimization capacities become readily available for ASP applications.}, language = {en} } @article{GebserGharibMerceretal.2009, author = {Gebser, Martin and Gharib, Mona and Mercer, Robert E. and Schaub, Torsten}, title = {Monotonic answer set programming}, issn = {0955-792X}, doi = {10.1093/logcom/exn040}, year = {2009}, abstract = {Answer set programming (ASP) does not allow for incrementally constructing answer sets or locally validating constructions like proofs by only looking at a part of the given program. In this article, we elaborate upon an alternative approach to ASP that allows for incremental constructions. Our approach draws its basic intuitions from the area of default logics. We investigate the feasibility of the concept of semi-monotonicity known from default logics as a basis of incrementality. On the one hand, every logic program has at least one answer set in our alternative setting, which moreover can be constructed incrementally based on generating rules. On the other hand, the approach may produce answer sets lacking characteristic properties of standard answer sets, such as being a model of the given program. We show how integrity constraints can be used to re-establish such properties, even up to correspondence with standard answer sets. Furthermore, we develop an SLD-like proof procedure for our incremental approach to ASP, which allows for query-oriented computations. Also, we provide a characterization of our definition of answer sets via a modification of Clarks completion. Based on this notion of program completion, we present an algorithm for computing the answer sets of a logic program in our approach.}, language = {en} } @article{GebserKaufmannSchaub2012, author = {Gebser, Martin and Kaufmann, Benjamin and Schaub, Torsten}, title = {Multi-threaded ASP solving with clasp}, series = {Theory and practice of logic programming}, volume = {12}, journal = {Theory and practice of logic programming}, number = {8}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {1471-0684}, doi = {10.1017/S1471068412000166}, pages = {525 -- 545}, year = {2012}, abstract = {We present the new multi-threaded version of the state-of-the-art answer set solver clasp. We detail its component and communication architecture and illustrate how they support the principal functionalities of clasp. Also, we provide some insights into the data representation used for different constraint types handled by clasp. All this is accompanied by an extensive experimental analysis of the major features related to multi-threading in clasp.}, language = {en} } @article{HermenegildoSchaub2010, author = {Hermenegildo, Manuel and Schaub, Torsten}, title = {Introduction to the technical communications of the 26th International Conference on Logic Programming : special issue}, issn = {1471-0684}, doi = {10.1017/S1471068410000153}, year = {2010}, language = {en} } @article{DelgrandeLiuSchaubetal.2007, author = {Delgrande, James Patrick and Liu, Daphne H. and Schaub, Torsten and Thiele, Sven}, title = {COBA 2.0 : a consistency-based belief change system}, year = {2007}, language = {en} } @article{GharibSchaubMercer2007, author = {Gharib, Mona and Schaub, Torsten and Mercer, Robert E.}, title = {Incremental answer set programming : a preliminary report}, year = {2007}, language = {en} } @article{DelgrandeSchaubTompits2006, author = {Delgrande, James Patrick and Schaub, Torsten and Tompits, Hans}, title = {An Extended Query language for action languages (and its application to aggregates and preferences)}, year = {2006}, language = {en} } @article{KonczakLinkeSchaub2003, author = {Konczak, Kathrin and Linke, Thomas and Schaub, Torsten}, title = {Graphs and colorings for answer set programming : abridged report}, issn = {1613-0073}, year = {2003}, language = {en} } @article{AngerGebserSchaub2006, author = {Anger, Christian and Gebser, Martin and Schaub, Torsten}, title = {Approaching the core of unfounded sets}, year = {2006}, language = {en} } @article{MileoSchaub2006, author = {Mileo, Alessandra and Schaub, Torsten}, title = {Extending ordered disjunctions for policy enforcement : preliminary report}, year = {2006}, language = {en} } @article{DelgrandeSchaubTompits2007, author = {Delgrande, James Patrick and Schaub, Torsten and Tompits, Hans}, title = {A preference-based framework for updating logic programs}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{GressmannJanhunenMerceretal.2006, author = {Gressmann, Jean and Janhunen, Tomi and Mercer, Robert E. and Schaub, Torsten and Thiele, Sven and Tichy, Richard}, title = {On probing and multi-threading in platypus}, year = {2006}, language = {en} } @article{GrellSchaubSelbig2006, author = {Grell, Susanne and Schaub, Torsten and Selbig, Joachim}, title = {Modelling biological networks by action languages via set programming}, issn = {0302-9743}, doi = {10.1007/11799573}, year = {2006}, language = {en} } @article{GerbserSchaub2006, author = {Gerbser, Martin and Schaub, Torsten}, title = {Tableau calculi for answer set programming}, issn = {0302-9743}, doi = {10.1007/11799573}, year = {2006}, language = {en} } @article{GerbserSchaub2006, author = {Gerbser, Martin and Schaub, Torsten}, title = {Characterizing (ASP) inferences by unit propagation}, year = {2006}, language = {en} } @phdthesis{Kaufmann2015, author = {Kaufmann, Benjamin}, title = {High performance answer set solving}, pages = {182}, year = {2015}, language = {en} } @article{DelgrandeSchaubTompitsetal.2004, author = {Delgrande, James Patrick and Schaub, Torsten and Tompits, Hans and Woltran, Stefan}, title = {On Computing belief change operations using quantifield boolean formulas}, issn = {0955-792X}, year = {2004}, abstract = {In this paper, we show how an approach to belief revision and belief contraction can be axiomatized by means of quantified Boolean formulas. Specifically, we consider the approach of belief change scenarios, a general framework that has been introduced for expressing different forms of belief change. The essential idea is that for a belief change scenario (K, R, C), the set of formulas K, representing the knowledge base, is modified so that the sets of formulas R and C are respectively true in, and consistent with the result. By restricting the form of a belief change scenario, one obtains specific belief change operators including belief revision, contraction, update, and merging. For both the general approach and for specific operators, we give a quantified Boolean formula such that satisfying truth assignments to the free variables correspond to belief change extensions in the original approach. Hence, we reduce the problem of determining the results of a belief change operation to that of satisfiability. This approach has several benefits. First, it furnishes an axiomatic specification of belief change with respect to belief change scenarios. This then leads to further insight into the belief change framework. Second, this axiomatization allows us to identify strict complexity bounds for the considered reasoning tasks. Third, we have implemented these different forms of belief change by means of existing solvers for quantified Boolean formulas. As well, it appears that this approach may be straightforwardly applied to other specific approaches to belief change}, language = {en} } @article{FloeterNicolasSchaubetal.2004, author = {Fl{\"o}ter, Andr{\´e} and Nicolas, Jacques and Schaub, Torsten and Selbig, Joachim}, title = {Threshold extraction in metabolite concentration data}, year = {2004}, abstract = {Motivation: Continued development of analytical techniques based on gas chromatography and mass spectrometry now facilitates the generation of larger sets of metabolite concentration data. An important step towards the understanding of metabolite dynamics is the recognition of stable states where metabolite concentrations exhibit a simple behaviour. Such states can be characterized through the identification of significant thresholds in the concentrations. But general techniques for finding discretization thresholds in continuous data prove to be practically insufficient for detecting states due to the weak conditional dependences in concentration data. Results: We introduce a method of recognizing states in the framework of decision tree induction. It is based upon a global analysis of decision forests where stability and quality are evaluated. It leads to the detection of thresholds that are both comprehensible and robust. Applied to metabolite concentration data, this method has led to the discovery of hidden states in the corresponding variables. Some of these reflect known properties of the biological experiments, and others point to putative new states}, language = {en} } @article{DelgrandeGharibMerceretal.2003, author = {Delgrande, James Patrick and Gharib, Mona and Mercer, Robert E. and Risch, V. and Schaub, Torsten}, title = {Lukaszewicz-style answer set programming : a preliminary report}, issn = {1613-0073}, year = {2003}, language = {en} }