TY  - JOUR
A1  - Gebser, Martin
A1  - Kaufmann, Benjamin
A1  - Schaub, Torsten H.
T1  - Multi-threaded ASP solving with clasp
JF  - Theory and practice of logic programming
N2  - 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.
Y1  - 2012
U6  - https://doi.org/10.1017/S1471068412000166
SN  - 1471-0684
VL  - 12
IS  - 8
SP  - 525
EP  - 545
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Mileo, Alessandra
A1  - Schaub, Torsten H.
A1  - Merico, Davide
A1  - Bisiani, Roberto
T1  - Knowledge-based multi-criteria optimization to support indoor positioning
JF  - Annals of mathematics and artificial intelligence
N2  - Indoor position estimation constitutes a central task in home-based assisted living environments. Such environments often rely on a heterogeneous collection of low-cost sensors whose diversity and lack of precision has to be compensated by advanced techniques for localization and tracking. Although there are well established quantitative methods in robotics and neighboring fields for addressing these problems, they lack advanced knowledge representation and reasoning capacities. Such capabilities are not only useful in dealing with heterogeneous and incomplete information but moreover they allow for a better inclusion of semantic information and more general homecare and patient-related knowledge. We address this problem and investigate how state-of-the-art localization and tracking methods can be combined with Answer Set Programming, as a popular knowledge representation and reasoning formalism. We report upon a case-study and provide a first experimental evaluation of knowledge-based position estimation both in a simulated as well as in a real setting.
KW  - Knowledge representation
KW  - Answer Set Programming
KW  - Wireless Sensor Networks
KW  - Localization
KW  - Tracking
Y1  - 2011
U6  - https://doi.org/10.1007/s10472-011-9241-2
SN  - 1012-2443
SN  - 1573-7470
VL  - 62
IS  - 3-4
SP  - 345
EP  - 370
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Durzinsky, Markus
A1  - Marwan, Wolfgang
A1  - Ostrowski, Max
A1  - Schaub, Torsten H.
A1  - Wagler, Annegret
T1  - Automatic network reconstruction using ASP
JF  - Theory and practice of logic programming
N2  - Building biological models by inferring functional dependencies from experimental data is an important issue in Molecular Biology. To relieve the biologist from this traditionally manual process, various approaches have been proposed to increase the degree of automation. However, available approaches often yield a single model only, rely on specific assumptions, and/or use dedicated, heuristic algorithms that are intolerant to changing circumstances or requirements in the view of the rapid progress made in Biotechnology. Our aim is to provide a declarative solution to the problem by appeal to Answer Set Programming (ASP) overcoming these difficulties. We build upon an existing approach to Automatic Network Reconstruction proposed by part of the authors. This approach has firm mathematical foundations and is well suited for ASP due to its combinatorial flavor providing a characterization of all models explaining a set of experiments. The usage of ASP has several benefits over the existing heuristic algorithms. First, it is declarative and thus transparent for biological experts. Second, it is elaboration tolerant and thus allows for an easy exploration and incorporation of biological constraints. Third, it allows for exploring the entire space of possible models. Finally, our approach offers an excellent performance, matching existing, special-purpose systems.
Y1  - 2011
U6  - https://doi.org/10.1017/S1471068411000287
SN  - 1471-0684
VL  - 11
SP  - 749
EP  - 766
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaminski, Roland
A1  - Schaub, Torsten H.
T1  - Complex optimization in answer set programming
JF  - Theory and practice of logic programming
N2  - 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.
KW  - Answer Set Programming
KW  - Preference Handling
KW  - Complex optimization
KW  - Meta-Programming
Y1  - 2011
U6  - https://doi.org/10.1017/S1471068411000329
SN  - 1471-0684
VL  - 11
IS  - 3
SP  - 821
EP  - 839
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
A1  - Veber, Philippe
T1  - Detecting inconsistencies in large biological networks with answer set programming
JF  - Theory and practice of logic programming
N2  - 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.
KW  - answer set programming
KW  - bioinformatics
KW  - consistency
KW  - diagnosis
Y1  - 2011
U6  - https://doi.org/10.1017/S1471068410000554
SN  - 1471-0684
VL  - 11
IS  - 5-6
SP  - 323
EP  - 360
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaufmann, Benjamin
A1  - Kaminski, Roland
A1  - Ostrowski, Max
A1  - Schaub, Torsten H.
A1  - Schneider, Marius
T1  - Potassco the Potsdam answer set solving collection
JF  - AI communications : AICOM ; the European journal on artificial intelligence
N2  - This paper gives an overview of the open source project Potassco, the Potsdam Answer Set Solving Collection, bundling tools for Answer Set Programming developed at the University of Potsdam.
KW  - Answer set programming
KW  - declarative problem solving
Y1  - 2011
U6  - https://doi.org/10.3233/AIC-2011-0491
SN  - 0921-7126
VL  - 24
IS  - 2
SP  - 107
EP  - 124
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Sabuncu, Orkunt
A1  - Schaub, Torsten H.
T1  - An incremental answer set programming based system for finite model computation
JF  - AI communications : AICOM ; the European journal on artificial intelligence
N2  - We address the problem of Finite Model Computation (FMC) of first-order theories and show that FMC can efficiently and transparently be solved by taking advantage of a recent extension of Answer Set Programming (ASP), called incremental Answer Set Programming (iASP). The idea is to use the incremental parameter in iASP programs to account for the domain size of a model. The FMC problem is then successively addressed for increasing domain sizes until an answer set, representing a finite model of the original first-order theory, is found. We implemented a system based on the iASP solver iClingo and demonstrate its competitiveness by showing that it slightly outperforms the winner of the FNT division of CADE's 2009 Automated Theorem Proving (ATP) competition on the respective benchmark collection.
KW  - Incremental answer set programming
KW  - finite model computation
Y1  - 2011
U6  - https://doi.org/10.3233/AIC-2011-0496
SN  - 0921-7126
VL  - 24
IS  - 2
SP  - 195
EP  - 212
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Gebser, Martin
A1  - Hinrichs, Henrik
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
T1  - xpanda: a (simple) preprocessor for adding multi-valued propositions to ASP
N2  - We introduce a simple approach extending the input language of Answer Set Programming (ASP) systems by multi-valued propositions. Our approach is implemented as a (prototypical) preprocessor translating logic programs with multi-valued propositions into logic programs with Boolean propositions only. Our translation is modular and heavily benefits from the expressive input language of ASP. The resulting approach, along with its implementation, allows for solving interesting constraint satisfaction problems in ASP, showing a good performance.
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-41466
ER  - 
TY  - JOUR
A1  - Hermenegildo, Manuel
A1  - Schaub, Torsten H.
T1  - Introduction to the technical communications of the 26th International Conference on Logic Programming : special issue
Y1  - 2010
UR  - http://www.cs.kuleuven.ac.be/~dtai/projects/ALP//TPLP/
U6  - https://doi.org/10.1017/S1471068410000153
SN  - 1471-0684
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Gharib, Mona
A1  - Mercer, Robert E.
A1  - Schaub, Torsten H.
T1  - Monotonic answer set programming
N2  - 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.
Y1  - 2009
UR  - http://logcom.oxfordjournals.org/
U6  - https://doi.org/10.1093/logcom/exn040
SN  - 0955-792X
ER  - 
TY  - JOUR
A1  - Brain, Martin
A1  - Gebser, Martin
A1  - Pührer, Jörg
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
A1  - Woltran, Stefan
T1  - "That is illogical, Captain!" : the debugging support tool spock for answer-set programs ; system description
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Brain, Martin
A1  - Gebser, Martin
A1  - Pührer, Jörg
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
A1  - Woltran, Stefan
T1  - Debugging ASP programs by means of ASP
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
A1  - Woltran, Stefan
T1  - Alternative characterizations for program equivalence under aswer-set semantics : a preliminary report
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
T1  - A preference-based framework for updating logic programs
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  - 
TY  - JOUR
A1  - Mileo, Alessandra
A1  - Schaub, Torsten H.
T1  - Qualitative constraint enforcement in advanced policy specification
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Lang, Jérôme
A1  - Schaub, Torsten H.
T1  - Belief change based on global minimisation
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
T1  - GrinGo : a new grounder for answer set programming
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Liu, Lengning
A1  - Namasivayam, Gayathri
A1  - Neumann, André
A1  - Schaub, Torsten H.
A1  - Truszczynski, Miroslaw
T1  - The first answer set programming system competition
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  - 
TY  - JOUR
A1  - Brain, Martin
A1  - Faber, Wolfgang
A1  - Maratea, Marco
A1  - Polleres, Axel
A1  - Schaub, Torsten H.
A1  - Schindlauer, Roman
T1  - What should an ASP solver output? : a multiple position paper
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaufmann, Benjamin
A1  - Neumann, André
A1  - Schaub, Torsten H.
T1  - Conflict-driven answer set enumeration
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  -