TY  - JOUR
A1  - Boesel, Andreas
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - Profiling answer set programming : the visualization component of the noMoRe System
Y1  - 2004
SN  - 3-540-23242-7
ER  - 
TY  - JOUR
A1  - Gressmann, Jean
A1  - Janhunen, Tomi
A1  - Mercer, Robert E.
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
A1  - Tichy, Richard
T1  - On probing and multi-threading in platypus
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Mileo, Alessandra
A1  - Schaub, Torsten H.
T1  - Extending ordered disjunctions for policy enforcement : preliminary report
Y1  - 2006
UR  - http://www.easychair.org/FLoC-06/PREFS-preproceedings.pdf
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Liu, Daphne H.
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
T1  - COBA 2.0 : a consistency-based belief change system
Y1  - 2006
UR  - http://www2.in.tu-clausthal.de/~tmbehrens/NMR_Proc_TR4.pdf
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
T1  - An Extended Query language for action languages (and its application to aggregates and preferences)
Y1  - 2006
UR  - http://www2.in.tu-clausthal.de/~tmbehrens/NMR_Proc_TR4.pdf
ER  - 
TY  - JOUR
A1  - Anger, Christian
A1  - Gebser, Martin
A1  - Linke, Thomas
A1  - Neumann, Andre
A1  - Schaub, Torsten H.
T1  - The nomore++ approach to answer set solving
Y1  - 2005
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/angelinesc05c.pdf
ER  - 
TY  - JOUR
A1  - Gressmann, Jean
A1  - Janhunen, Tomi
A1  - Mercer, Robert E.
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
A1  - Tichy, Richard
T1  - Platypus : a platform for distributed answer set solving
Y1  - 2005
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/grjamescthti05a.pdf
ER  - 
TY  - JOUR
A1  - Anger, Christian
A1  - Gebser, Martin
A1  - Linke, Thomas
A1  - Neumann, Andre
A1  - Schaub, Torsten H.
T1  - The nomore++ approach to answer set solving
Y1  - 2005
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/angelinesc05c.pdf
ER  - 
TY  - JOUR
A1  - Grell, Susanne
A1  - Konczak, Kathrin
A1  - Schaub, Torsten H.
T1  - nomore) : a system for computing preferred Answer Sets
Y1  - 2005
SN  - 0302-9743
ER  - 
TY  - JOUR
A1  - Anger, Christian
A1  - Konczak, Kathrin
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - A Glimpse of Answer Set Programming
Y1  - 2005
UR  - http://www.cs.uni-potsdam.de/~konczak/Papers/ankolisc05.pdf
SN  - 0170-4516
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Expressing default logic variants in default logic
N2  - Reiter's default logic is one of the best known and most studied of the approaches to nonmonotonic reasoning. Several variants of default logic have subsequently been proposed to give systems with properties differing from the original. In this paper, we examine the relationship between default logic and its major variants. We accomplish this by translating a default theory under a variant interpretation into a second default theory, under the original Reiter semantics, wherein the variant interpretation is respected. That is, in each case we show that, given an extension of a translated theory, one may extract an extension of the original variant default logic theory. We show how constrained, rational, justified, and cumulative default logic can be expressed in Reiter's default logic. As well, we show how Reiter's default logic can be expressed in rational default logic. From this, we suggest that any such variant can be similarly treated. Consequently, we provide a unification of default logics, showing how the original formulation of default logic may express its variants. Moreover, the translations clearly express the relationships between alternative approaches to default logic. The translations themselves are shown to generally have good properties. Thus, in at least a theoretical sense, we show that these variants are in a sense superfluous, in that for any of these variants of default logic, we can exactly mimic the behaviour of a variant in standard default logic. As well, the translations lend insight into means of classifying the expressive power of default logic variants; specifically we suggest that the property of semi-monotonicity represents a division with respect to expressibility, whereas regularity and cumulativity do not
Y1  - 2005
SN  - 0955-792X
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  - Borchert, P.
A1  - Anger, Christian
A1  - Schaub, Torsten H.
A1  - Truszczynski, M.
T1  - Towards systematic benchmarking in answer set programming : the dagstuhl initiative
Y1  - 2004
SN  - 3-540- 20721-x
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Two approaches to merging knowledge bases
Y1  - 2004
SN  - 3-540-23242-7
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
T1  - Domain-specific preference for causal reasoning and planning
Y1  - 2004
SN  - 1-577-35201-7
ER  - 
TY  - JOUR
A1  - Flöter, André
A1  - Selbig, Joachim
A1  - Schaub, Torsten H.
T1  - Finding metabolic pathways in decision forests
Y1  - 2004
SN  - 3-540-23221-4
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Consistency-based approaches to merging knowledge based : preliminary report
Y1  - 2004
UR  - http://www.pims.math.ca/science/2004/NMR/papers/paper17.pdf
SN  - 92-990021-0-X
ER  - 
TY  - JOUR
A1  - Flöter, André
A1  - Nicolas, Jacques
A1  - Schaub, Torsten H.
A1  - Selbig, Joachim
T1  - Threshold extraction in metabolite concentration data
N2  - 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
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
A1  - Wang, Kewen
T1  - A classification and survey of preference handling approchaches in nonmonotonic reasoning
N2  - In recent years, there has been a large amount of disparate work concerning the representation and reasoning with qualitative preferential information by means of approaches to nonmonotonic reasoning. Given the variety of underlying systems, assumptions, motivations, and intuitions, it is difficult to compare or relate one approach with another. Here, we present an overview and classification for approaches to dealing with preference. A set of criteria for classifying approaches is given, followed by a set of desiderata that an approach might be expected to satisfy. A comprehensive set of approaches is subsequently given and classified with respect to these sets of underlying principles
Y1  - 2004
SN  - 0824-7935
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Reasoning with sets of preferences in default logic
N2  - We present a general approach for representing and reasoning with sets of defaults in default logic, focusing on reasoning about preferences among sets of defaults. First, we consider how to control the application of a set of defaults so that either all apply (if possible) or none do (if not). From this, an approach to dealing with preferences among sets of default rules is developed. We begin with an ordered default theory, consisting of a standard default theory, but with possible preferences on sets of rules. This theory is transformed into a second, standard default theory wherein the preferences are respected. The approach differs from other work, in that we obtain standard default theories and do not rely on prioritized versions of default logic. In practical terms this means we can immediately use existing default logic theorem provers for an implementation. Also, we directly generate just those extensions containing the most preferred applied rules; in contrast, most previous approaches generate all extensions, then select the most preferred. In a major application of the approach, we show how semimonotonic default theories can be encoded so that reasoning can be carried out at the object level. With this, we can reason about default extensions from within the framework of a standard default logic. Hence one can encode notions such as skeptical and credulous conclusions, and can reason about such conclusions within a single extension
Y1  - 2004
SN  - 0824-7935
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
T1  - A framework for compiling preferences in logic programs
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Reasoning credulously and skeptically within a single extension
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Konczak, Kathrin
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - Graphs and colorings for answer set programming : abridged report
Y1  - 2003
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/kolisch03a.pdf
SN  - 1613-0073
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - On the relation between Reiterïs default logic and its (major) variants
Y1  - 2003
SN  - 3-540- 409494-5
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Mercer, Robert E.
A1  - Schaub, Torsten H.
T1  - Optimality theory throught default logic
Y1  - 2003
SN  - 3-540-20059-2
ER  - 
TY  - JOUR
A1  - Konczak, Kathrin
A1  - Schaub, Torsten H.
A1  - Linke, Thomas
T1  - Graphs and colorings for answer set programming with prefernces : preliminary report
Y1  - 2003
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/koschli03a.pdf
SN  - 1613-0073
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Gharib, Mona
A1  - Mercer, Robert E.
A1  - Risch, V.
A1  - Schaub, Torsten H.
T1  - Lukaszewicz-style answer set programming : a preliminary report
Y1  - 2003
UR  - http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-78/
SN  - 1613-0073
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Wang, Kewen
T1  - A semantic framework for prefernce handling in answer set programming
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - A concictency-based paradigm for belief change
Y1  - 2003
SN  - 0004-3702
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
T1  - Antwortmengenprogrammierung
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Konczak, Kathrin
A1  - Schaub, Torsten H.
A1  - Linke, Thomas
T1  - Graphs and colorings for answer set programming with preferences
N2  - The integration of preferences into answer set programming constitutes an important practical device for distinguishing certain preferred answer sets from non-preferred ones. To this end, we elaborate upon rule dependency graphs and their colorings for characterizing different preference handling strategies found in the literature. We start from a characterization of (three types of) preferred answer sets in terms of totally colored dependency graphs. In particular, we demonstrate that this approach allows us to capture all three approaches to preferences in a uniform setting by means of the concept of a height function. In turn, we exemplarily develop an operational characterization of preferred answer sets in terms of operators on partial colorings for one particular strategy. In analogy to the notion of a derivation in proof theory, our operational characterization is expressed as a (non-deterministically formed) sequence of colorings, gradually turning an uncolored graph into a totally colored one
Y1  - 2003
SN  - 0169-2968
ER  - 
TY  - JOUR
A1  - Flöter, André
A1  - Nicolas, Jacques
A1  - Schaub, Torsten H.
A1  - Selbig, Joachim
T1  - Threshold extraction in metabolite concentration data
Y1  - 2003
UR  - http://www.cs.uni-potsdam.de/wv/pdfformat/floeterGCB2003.pdf
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
A1  - Wang, Kewen
T1  - Towards a classification of preference handling approaches in nonmonotonic reasoning
Y1  - 2002
SN  - 1-577-35166-5
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Mercer, Robert E.
A1  - Schaub, Torsten H.
T1  - Optimality Theory via Default Logic
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Reasoning credulously and skeptically within a single extension
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Hunter, Anthony
A1  - Schaub, Torsten H.
T1  - COBA: a consistency-based belief revision system
Y1  - 2002
SN  - 3-540-44190-5
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Wang, T.
T1  - Preferred well-founded semantics for logic programming by alternating fixpoints : preliminary report
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Obermeier, Philipp
A1  - Schaub, Torsten H.
A1  - Ratsch-Heitmann, Michel
A1  - Runge, Mario
T1  - Routing driverless transport vehicles in car assembly with answer set programming
JF  - Theory and practice of logic programming
N2  - Automated storage and retrieval systems are principal components of modern production and warehouse facilities. In particular, automated guided vehicles nowadays substitute human-operated pallet trucks in transporting production materials between storage locations and assembly stations. While low-level control systems take care of navigating such driverless vehicles along programmed routes and avoid collisions even under unforeseen circumstances, in the common case of multiple vehicles sharing the same operation area, the problem remains how to set up routes such that a collection of transport tasks is accomplished most effectively. We address this prevalent problem in the context of car assembly at Mercedes-Benz Ludwigsfelde GmbH, a large-scale producer of commercial vehicles, where routes for automated guided vehicles used in the production process have traditionally been hand-coded by human engineers. Such adhoc methods may suffice as long as a running production process remains in place, while any change in the factory layout or production targets necessitates tedious manual reconfiguration, not to mention the missing portability between different production plants. Unlike this, we propose a declarative approach based on Answer Set Programming to optimize the routes taken by automated guided vehicles for accomplishing transport tasks. The advantages include a transparent and executable problem formalization, provable optimality of routes relative to objective criteria, as well as elaboration tolerance towards particular factory layouts and production targets. Moreover, we demonstrate that our approach is efficient enough to deal with the transport tasks evolving in realistic production processes at the car factory of Mercedes-Benz Ludwigsfelde GmbH.
KW  - automated guided vehicle routing
KW  - car assembly operations
KW  - answer set programming
Y1  - 2018
U6  - https://doi.org/10.1017/S1471068418000182
SN  - 1471-0684
SN  - 1475-3081
VL  - 18
IS  - 3-4
SP  - 520
EP  - 534
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaminski, Roland
A1  - Kaufmann, Benjamin
A1  - Lühne, Patrick
A1  - Obermeier, Philipp
A1  - Ostrowski, Max
A1  - Romero Davila, Javier
A1  - Schaub, Torsten H.
A1  - Schellhorn, Sebastian
A1  - Wanko, Philipp
T1  - The Potsdam Answer Set Solving Collection 5.0
JF  - Künstliche Intelligenz
N2  - The Potsdam answer set solving collection, or Potassco for short, bundles various tools implementing and/or applying answer set programming. The article at hand succeeds an earlier description of the Potassco project published in Gebser et al. (AI Commun 24(2):107-124, 2011). Hence, we concentrate in what follows on the major features of the most recent, fifth generation of the ASP system clingo and highlight some recent resulting application systems.
Y1  - 2018
U6  - https://doi.org/10.1007/s13218-018-0528-x
SN  - 0933-1875
SN  - 1610-1987
VL  - 32
IS  - 2-3
SP  - 181
EP  - 182
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Haubelt, Christian
A1  - Neubauer, Kai
A1  - Schaub, Torsten H.
A1  - Wanko, Philipp
T1  - Design space exploration with answer set programming
JF  - Künstliche Intelligenz
N2  - The aim of our project design space exploration with answer set programming is to develop a general framework based on Answer Set Programming (ASP) that finds valid solutions to the system design problem and simultaneously performs Design Space Exploration (DSE) to find the most favorable alternatives. We leverage recent developments in ASP solving that allow for tight integration of background theories to create a holistic framework for effective DSE.
Y1  - 2018
U6  - https://doi.org/10.1007/s13218-018-0530-3
SN  - 0933-1875
SN  - 1610-1987
VL  - 32
IS  - 2-3
SP  - 205
EP  - 206
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - GEN
A1  - Lifschitz, Vladimir
A1  - Schaub, Torsten H.
A1  - Woltran, Stefan
T1  - Interview with Vladimir Lifschitz
T2  - Künstliche Intelligenz
N2  - This interview with Vladimir Lifschitz was conducted by Torsten Schaub at the University of Texas at Austin in August 2017. The question set was compiled by Torsten Schaub and Stefan Woltran.
Y1  - 2018
U6  - https://doi.org/10.1007/s13218-018-0552-x
SN  - 0933-1875
SN  - 1610-1987
VL  - 32
IS  - 2-3
SP  - 213
EP  - 218
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - GEN
A1  - Brewka, Gerhard
A1  - Schaub, Torsten H.
A1  - Woltran, Stefan
T1  - Interview with Gerhard Brewka
T2  - Künstliche Intelligenz
N2  - This interview with Gerhard Brewka was conducted by correspondance in May 2018. The question set was compiled by Torsten Schaub and Stefan Woltran.
Y1  - 2018
U6  - https://doi.org/10.1007/s13218-018-0549-5
SN  - 0933-1875
SN  - 1610-1987
VL  - 32
IS  - 2-3
SP  - 219
EP  - 221
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Dimopoulos, Yannis
A1  - Gebser, Martin
A1  - Lühne, Patrick
A1  - Romero Davila, Javier
A1  - Schaub, Torsten H.
T1  - plasp 3
BT  - Towards Effective ASP Planning
JF  - Theory and practice of logic programming
N2  - We describe the new version of the Planning Domain Definition Language (PDDL)-to-Answer Set Programming (ASP) translator plasp. First, it widens the range of accepted PDDL features. Second, it contains novel planning encodings, some inspired by Satisfiability Testing (SAT) planning and others exploiting ASP features such as well-foundedness. All of them are designed for handling multivalued fluents in order to capture both PDDL as well as SAS planning formats. Third, enabled by multishot ASP solving, it offers advanced planning algorithms also borrowed from SAT planning. As a result, plasp provides us with an ASP-based framework for studying a variety of planning techniques in a uniform setting. Finally, we demonstrate in an empirical analysis that these techniques have a significant impact on the performance of ASP planning.
KW  - knowledge representation and nonmonotonic reasoning
KW  - technical notes and rapid communications
KW  - answer set programming
KW  - automated planning
KW  - action and change
Y1  - 2019
U6  - https://doi.org/10.1017/S1471068418000583
SN  - 1471-0684
SN  - 1475-3081
VL  - 19
IS  - 3
SP  - 477
EP  - 504
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - GEN
A1  - Neubauer, Kai
A1  - Haubelt, Christian
A1  - Wanko, Philipp
A1  - Schaub, Torsten H.
T1  - Utilizing quad-trees for efficient design space exploration with partial assignment evaluation
T2  - 2018 23rd Asia and South Pacific Design Automation Conference (ASP-DAC)
N2  - Recently, it has been shown that constraint-based symbolic solving techniques offer an efficient way for deciding binding and routing options in order to obtain a feasible system level implementation. In combination with various background theories, a feasibility analysis of the resulting system may already be performed on partial solutions. That is, infeasible subsets of mapping and routing options can be pruned early in the decision process, which fastens the solving accordingly. However, allowing a proper design space exploration including multi-objective optimization also requires an efficient structure for storing and managing non-dominated solutions. In this work, we propose and study the usage of the Quad-Tree data structure in the context of partial assignment evaluation during system synthesis. Out experiments show that unnecessary dominance checks can be avoided, which indicates a preference of Quad-Trees over a commonly used list-based implementation for large combinatorial optimization problems.
Y1  - 2018
SN  - 978-1-5090-0602-1
U6  - https://doi.org/10.1109/ASPDAC.2018.8297362
SN  - 2153-6961
SP  - 434
EP  - 439
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Frioux, Clémence
A1  - Schaub, Torsten H.
A1  - Schellhorn, Sebastian
A1  - Siegel, Anne
A1  - Wanko, Philipp
T1  - Hybrid metabolic network completion
JF  - Theory and practice of logic programming
N2  - Metabolic networks play a crucial role in biology since they capture all chemical reactions in an organism. While there are networks of high quality for many model organisms, networks for less studied organisms are often of poor quality and suffer from incompleteness. To this end, we introduced in previous work an answer set programming (ASP)-based approach to metabolic network completion. Although this qualitative approach allows for restoring moderately degraded networks, it fails to restore highly degraded ones. This is because it ignores quantitative constraints capturing reaction rates. To address this problem, we propose a hybrid approach to metabolic network completion that integrates our qualitative ASP approach with quantitative means for capturing reaction rates. We begin by formally reconciling existing stoichiometric and topological approaches to network completion in a unified formalism. With it, we develop a hybrid ASP encoding and rely upon the theory reasoning capacities of the ASP system dingo for solving the resulting logic program with linear constraints over reals. We empirically evaluate our approach by means of the metabolic network of Escherichia coli. Our analysis shows that our novel approach yields greatly superior results than obtainable from purely qualitative or quantitative approaches.
KW  - answer set programming
KW  - metabolic network
KW  - gap-filling
KW  - linear programming
KW  - hybrid solving
KW  - bioinformatics
Y1  - 2018
U6  - https://doi.org/10.1017/S1471068418000455
SN  - 1471-0684
SN  - 1475-3081
VL  - 19
IS  - 1
SP  - 83
EP  - 108
PB  - Cambridge University Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Banbara, Mutsunori
A1  - Inoue, Katsumi
A1  - Kaufmann, Benjamin
A1  - Okimoto, Tenda
A1  - Schaub, Torsten H.
A1  - Soh, Takehide
A1  - Tamura, Naoyuki
A1  - Wanko, Philipp
T1  - teaspoon
BT  - solving the curriculum-based course timetabling problems with answer set programming
JF  - Annals of operation research
N2  - Answer Set Programming (ASP) is an approach to declarative problem solving, combining a rich yet simple modeling language with high performance solving capacities. We here develop an ASP-based approach to curriculum-based course timetabling (CB-CTT), one of the most widely studied course timetabling problems. The resulting teaspoon system reads a CB-CTT instance of a standard input format and converts it into a set of ASP facts. In turn, these facts are combined with a first-order encoding for CB-CTT solving, which can subsequently be solved by any off-the-shelf ASP systems. We establish the competitiveness of our approach by empirically contrasting it to the best known bounds obtained so far via dedicated implementations. Furthermore, we extend the teaspoon system to multi-objective course timetabling and consider minimal perturbation problems.
KW  - Educational timetabling
KW  - Course timetabling
KW  - Answer set programming
KW  - Multi-objective optimization
KW  - Minimal perturbation problems
Y1  - 2018
U6  - https://doi.org/10.1007/s10479-018-2757-7
SN  - 0254-5330
SN  - 1572-9338
VL  - 275
IS  - 1
SP  - 3
EP  - 37
PB  - Springer
CY  - Dordrecht
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  - Besnard, Philippe
A1  - Fanselow, Gisbert
A1  - Schaub, Torsten H.
T1  - Optimality theory as a family of cumulative logics
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Lindauer, Marius
A1  - Hoos, Holger
A1  - Leyton-Brown, Kevin
A1  - Schaub, Torsten H.
T1  - Automatic construction of parallel portfolios via algorithm configuration
JF  - Artificial intelligence
N2  - Since 2004, increases in computational power described by Moore's law have substantially been realized in the form of additional cores rather than through faster clock speeds. To make effective use of modern hardware when solving hard computational problems, it is therefore necessary to employ parallel solution strategies. In this work, we demonstrate how effective parallel solvers for propositional satisfiability (SAT), one of the most widely studied NP-complete problems, can be produced automatically from any existing sequential, highly parametric SAT solver. Our Automatic Construction of Parallel Portfolios (ACPP) approach uses an automatic algorithm configuration procedure to identify a set of configurations that perform well when executed in parallel. Applied to two prominent SAT solvers, Lingeling and clasp, our ACPP procedure identified 8-core solvers that significantly outperformed their sequential counterparts on a diverse set of instances from the application and hard combinatorial category of the 2012 SAT Challenge. We further extended our ACPP approach to produce parallel portfolio solvers consisting of several different solvers by combining their configuration spaces. Applied to the component solvers of the 2012 SAT Challenge gold medal winning SAT Solver pfolioUZK, our ACPP procedures produced a significantly better-performing parallel SAT solver.
KW  - Algorithm configuration
KW  - Parallel SAT solving
KW  - Algorithm portfolios
KW  - Programming by optimization
KW  - Automated parallelization
Y1  - 2016
U6  - https://doi.org/10.1016/j.artint.2016.05.004
SN  - 0004-3702
SN  - 1872-7921
VL  - 244
SP  - 272
EP  - 290
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Cabalar, Pedro
A1  - Dieguez, Martin
A1  - Schaub, Torsten H.
A1  - Schuhmann, Anna
T1  - Towards metric temporal answer set programming
JF  - Theory and practice of logic programming
N2  - We elaborate upon the theoretical foundations of a metric temporal extension of Answer Set Programming. In analogy to previous extensions of ASP with constructs from Linear Temporal and Dynamic Logic, we accomplish this in the setting of the logic of Here-and-There and its non-monotonic extension, called Equilibrium Logic. More precisely, we develop our logic on the same semantic underpinnings as its predecessors and thus use a simple time domain of bounded time steps. This allows us to compare all variants in a uniform framework and ultimately combine them in a common implementation.
Y1  - 2020
U6  - https://doi.org/10.1017/S1471068420000307
SN  - 1471-0684
SN  - 1475-3081
VL  - 20
IS  - 5
SP  - 783
EP  - 798
PB  - Cambridge Univ. Press
CY  - Cambridge [u.a.]
ER  - 
TY  - JOUR
A1  - Bibel, Wolfgang
A1  - Brüning, Stefan
A1  - Otten, Jens
A1  - Rath, Thomas
A1  - Schaub, Torsten H.
T1  - Compressions and extensions
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Compiling specificity into approaches to nonmonotonic reasoning
Y1  - 1997
SN  - 0004-3702
ER  - 
TY  - JOUR
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - Towards a classification of default logic
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Brüning, Stefan
T1  - Prolog technology for default reasoning
Y1  - 1996
SN  - 0-471-96809-9
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - A simple signed system for paraconsistent reasoning
Y1  - 1996
SN  - 3-540-61630-6
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Thielscher, Michael
T1  - Skeptical query-answering in constrained default logic
Y1  - 1996
SN  - 3-540-61313-7
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Brüning, Stefan
A1  - Nicolas, Pascal
T1  - XRay : a prolog technology theorem prover for default reasoning: a system description
Y1  - 1996
SN  - 3-540-61511-3
ER  - 
TY  - JOUR
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - Putting default logics in perspective
Y1  - 1996
SN  - 3-540-61708-6
ER  - 
TY  - JOUR
A1  - Brüning, Stefan
A1  - Schaub, Torsten H.
T1  - A model-based approach to consistency-checking
Y1  - 1996
SN  - 3-540-61286-6
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  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaufmann, Benjamin
A1  - Neumann, André
A1  - Schaub, Torsten H.
T1  - Conflict-driven answer set solving
Y1  - 2007
SN  - 978-1-57735-323-2
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Liu, Daphne H.
A1  - Schaub, Torsten H.
A1  - Thiele, Sven
T1  - COBA 2.0 : a consistency-based belief change system
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - A consistency-based framework for merging knowledge bases
Y1  - 2007
SN  - 1570-8683
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Gharib, Mona
A1  - Schaub, Torsten H.
T1  - Incremental answer sets and their computation
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Schaub, Torsten H.
T1  - Generic tableaux for answer set programming
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Kaufmann, Benjamin
A1  - Neumann, André
A1  - Schaub, Torsten H.
T1  - Clasp : a conflict-driven answer set solver
Y1  - 2007
SN  - 978-3-540- 72199-4
ER  - 
TY  - JOUR
A1  - Benhammadi, Farid
A1  - Nicolas, Pascal
A1  - Schaub, Torsten H.
T1  - Extension calculus and query answering in prioritized default logic
Y1  - 1998
SN  - 3-540-64993-X
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - A context-based framework for default logics
Y1  - 1993
SN  - 0-262-51071-5
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
A1  - Tompits, Hans
T1  - A general framework for expressing preferences in causal reasoning and planning
N2  - We consider the problem of representing arbitrary preferences in causal reasoning and planning systems. In planning, a preference may be seen as a goal or constraint that is desirable, but not necessary, to satisfy. To begin, we define a very general query language for histories, or interleaved sequences of world states and actions. Based on this, we specify a second language in which preferences are defined. A single preference defines a binary relation on histories, indicating that one history is preferred to the other. From this, one can define global preference orderings on the set of histories, the maximal elements of which are the preferred histories. The approach is very general and flexible; thus it constitutes a base language in terms of which higher-level preferences may be defined. To this end, we investigate two fundamental types of preferences that we call choice and temporal preferences. We consider concrete strategies for these types of preferences and encode them in terms of our framework. We suggest how to express aggregates in the approach, allowing, e.g. the expression of a preference for histories with lowest total action costs. Last, our approach can be used to express other approaches and so serves as a common framework in which such approaches can be expressed and compared. We illustrate this by indicating how an approach due to Son and Pontelli can be encoded in our approach, as well as the language PDDL3.
Y1  - 2007
UR  - http://logcom.oxfordjournals.org/
U6  - https://doi.org/10.1093/logcom/exm046
SN  - 0955-792X
ER  - 
TY  - JOUR
A1  - Gebser, Martin
A1  - Schaub, Torsten H.
T1  - Tableau calculi for logic programs under answer set semantics
JF  - ACM transactions on computational logic
N2  - We introduce formal proof systems based on tableau methods for analyzing computations in Answer Set Programming (ASP). Our approach furnishes fine-grained instruments for characterizing operations as well as strategies of ASP solvers. The granularity is detailed enough to capture a variety of propagation and choice methods of algorithms used for ASP solving, also incorporating SAT-based and conflict-driven learning approaches to some extent. This provides us with a uniform setting for identifying and comparing fundamental properties of ASP solving approaches. In particular, we investigate their proof complexities and show that the run-times of best-case computations can vary exponentially between different existing ASP solvers. Apart from providing a framework for comparing ASP solving approaches, our characterizations also contribute to their understanding by pinning down the constitutive atomic operations. Furthermore, our framework is flexible enough to integrate new inference patterns, and so to study their relation to existing ones. To this end, we generalize our approach and provide an extensible basis aiming at a modular incorporation of additional language constructs. This is exemplified by augmenting our basic tableau methods with cardinality constraints and disjunctions.
KW  - Theory
KW  - Answer Set Programming
KW  - tableau calculi
KW  - proof complexity
Y1  - 2013
U6  - https://doi.org/10.1145/2480759.2480767
SN  - 1529-3785
VL  - 14
IS  - 2
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - An approach to query-answering in Reiter's default logic and the underlying existence of extensions problem.
Y1  - 1998
SN  - 3-540-65141-1
ER  - 
TY  - JOUR
A1  - Volkmann, Gerald
A1  - Linke, Thomas
A1  - Waschulzik, Thomas
A1  - Ohmes, Rick
A1  - Schaub, Torsten H.
A1  - Wischnewsky, M.
T1  - HExProSA - ein hybrides Expertensystem zur Prozeßkontrolle und Störfallanalyse von Abwasserbehandlungsanlagen : Erfahrungen bei der Evaluierung eines Prototypen
Y1  - 1998
UR  - http://home.zait.uni-bremen.de/~gerald/papers/pius-papers.html
ER  - 
TY  - JOUR
A1  - Benhammadi, Farid
A1  - Nicolas, Pascal
A1  - Schaub, Torsten H.
T1  - Extension calculus and query answering in prioritized default logic
Y1  - 1998
SN  - 3-540- 64993-X
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - Signed systems for paraconsistent reasoning
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Nicolas, Pascal
A1  - Schaub, Torsten H.
T1  - The XRay system : an implementation platform for local query-answering in default logics
Y1  - 1998
SN  - 3-540-65312-0
ER  - 
TY  - JOUR
A1  - Nicolas, Pascal
A1  - Schaub, Torsten H.
T1  - Un cadre général pour l'interrogation automatique en logiques des défauts
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - Characterization of non-monotone non-constructive systems
Y1  - 1998
SN  - 1012-2443
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Brüning, Stefan
T1  - Prolog technology for default reasoning : proof theory and compilation techniques
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - Signed systems for paraconsistent reasoning
Y1  - 1998
SN  - 0168-7433
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
T1  - The family of default logics
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Reasoning with sets of preferences in default logic
Y1  - 1998
SN  - 3-540- 65271-x
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  - Gharib, Mona
A1  - Schaub, Torsten H.
A1  - Mercer, Robert E.
T1  - Incremental answer set programming : a preliminary report
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten H.
T1  - Compiling reasoning with and about preferences into default logic
Y1  - 1997
SN  - 1-558-60480-4
SN  - 1045-0823
ER  - 
TY  - JOUR
A1  - Linke, Thomas
A1  - Schaub, Torsten H.
T1  - Lemma handling in default logic theorem provers
Y1  - 1995
SN  - 3540601120
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - An approach to context-based default reasoning
Y1  - 1995
SN  - 0169-2968
ER  - 
TY  - JOUR
A1  - Thielscher, Michael
A1  - Schaub, Torsten H.
T1  - Default reasoning by deductive planning
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Kaminski, Roland
A1  - Schaub, Torsten H.
A1  - Siegel, Anne
A1  - Videla, Santiago
T1  - Minimal intervention strategies in logical signaling networks with ASP
JF  - Theory and practice of logic programming
N2  - Proposing relevant perturbations to biological signaling networks is central to many problems in biology and medicine because it allows for enabling or disabling certain biological outcomes. In contrast to quantitative methods that permit fine-grained (kinetic) analysis, qualitative approaches allow for addressing large-scale networks. This is accomplished by more abstract representations such as logical networks. We elaborate upon such a qualitative approach aiming at the computation of minimal interventions in logical signaling networks relying on Kleene's three-valued logic and fixpoint semantics. We address this problem within answer set programming and show that it greatly outperforms previous work using dedicated algorithms.
Y1  - 2013
U6  - https://doi.org/10.1017/S1471068413000422
SN  - 1471-0684
VL  - 13
SP  - 675
EP  - 690
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Nicolas, Pascal
T1  - An implementation platform for query-answering in default logics : the XRay system, its implementation and evaluation
Y1  - 1997
SN  - 3-540-63255-7
ER  - 
TY  - JOUR
A1  - Schaub, Torsten H.
A1  - Nicolas, Pascal
T1  - An implementation platform for query-answering in default logics : theoretical underpinnings
Y1  - 1997
SN  - 3-540-63614-5
ER  - 
TY  - JOUR
A1  - Besnard, Philippe
A1  - Schaub, Torsten H.
T1  - Circumscribing inconsistency
Y1  - 1997
SN  - 1-558-60480-4
SN  - 1045-0823
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  - 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  - Kaufmann, Benjamin
A1  - Schaub, Torsten H.
T1  - Conflict-driven answer set solving: From theory to practice
JF  - Artificial intelligence
N2  - We introduce an approach to computing answer sets of logic programs, based on concepts successfully applied in Satisfiability (SAT) checking. The idea is to view inferences in Answer Set Programming (ASP) as unit propagation on nogoods. This provides us with a uniform constraint-based framework capturing diverse inferences encountered in ASP solving. Moreover, our approach allows us to apply advanced solving techniques from the area of SAT. As a result, we present the first full-fledged algorithmic framework for native conflict-driven ASP solving. Our approach is implemented in the ASP solver clasp that has demonstrated its competitiveness and versatility by winning first places at various solver contests.
KW  - Answer set programming
KW  - Logic programming
KW  - Nonmonotonic reasoning
Y1  - 2012
U6  - https://doi.org/10.1016/j.artint.2012.04.001
SN  - 0004-3702
VL  - 187
IS  - 8
SP  - 52
EP  - 89
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ostrowski, Max
A1  - Schaub, Torsten H.
T1  - ASP modulo CSP The clingcon system
JF  - Theory and practice of logic programming
N2  - We present the hybrid ASP solver clingcon, combining the simple modeling language and the high performance Boolean solving capacities of Answer Set Programming (ASP) with techniques for using non-Boolean constraints from the area of Constraint Programming (CP). The new clingcon system features an extended syntax supporting global constraints and optimize statements for constraint variables. The major technical innovation improves the interaction between ASP and CP solver through elaborated learning techniques based on irreducible inconsistent sets. A broad empirical evaluation shows that these techniques yield a performance improvement of an order of magnitude.
Y1  - 2012
U6  - https://doi.org/10.1017/S1471068412000142
SN  - 1471-0684
VL  - 12
SP  - 485
EP  - 503
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
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  - Hoos, Holger
A1  - Lindauer, Marius
A1  - Schaub, Torsten H.
T1  - claspfolio 2
BT  - advances in algorithm selection for answer set programming
JF  - Theory and practice of logic programming
N2  - Building on the award-winning, portfolio-based ASP solver claspfolio, we present claspfolio 2, a modular and open solver architecture that integrates several different portfolio-based algorithm selection approaches and techniques. The claspfolio 2 solver framework supports various feature generators, solver selection approaches, solver portfolios, as well as solver-schedule-based pre-solving techniques. The default configuration of claspfolio 2 relies on a light-weight version of the ASP solver clasp to generate static and dynamic instance features. The flexible open design of claspfolio 2 is a distinguishing factor even beyond ASP. As such, it provides a unique framework for comparing and combining existing portfolio-based algorithm selection approaches and techniques in a single, unified framework. Taking advantage of this, we conducted an extensive experimental study to assess the impact of different feature sets, selection approaches and base solver portfolios. In addition to gaining substantial insights into the utility of the various approaches and techniques, we identified a default configuration of claspfolio 2 that achieves substantial performance gains not only over clasp's default configuration and the earlier version of claspfolio, but also over manually tuned configurations of clasp.
Y1  - 2014
U6  - https://doi.org/10.1017/S1471068414000210
SN  - 1471-0684
SN  - 1475-3081
VL  - 14
SP  - 569
EP  - 585
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Videla, Santiago
A1  - Guziolowski, Carito
A1  - Eduati, Federica
A1  - Thiele, Sven
A1  - Gebser, Martin
A1  - Nicolas, Jacques
A1  - Saez-Rodriguez, Julio
A1  - Schaub, Torsten H.
A1  - Siegel, Anne
T1  - Learning Boolean logic models of signaling networks with ASP
JF  - Theoretical computer science
N2  - Boolean networks provide a simple yet powerful qualitative modeling approach in systems biology. However, manual identification of logic rules underlying the system being studied is in most cases out of reach. Therefore, automated inference of Boolean logical networks from experimental data is a fundamental question in this field. This paper addresses the problem consisting of learning from a prior knowledge network describing causal interactions and phosphorylation activities at a pseudo-steady state, Boolean logic models of immediate-early response in signaling transduction networks. The underlying optimization problem has been so far addressed through mathematical programming approaches and the use of dedicated genetic algorithms. In a recent work we have shown severe limitations of stochastic approaches in this domain and proposed to use Answer Set Programming (ASP), considering a simpler problem setting. Herein, we extend our previous work in order to consider more realistic biological conditions including numerical datasets, the presence of feedback-loops in the prior knowledge network and the necessity of multi-objective optimization. In order to cope with such extensions, we propose several discretization schemes and elaborate upon our previous ASP encoding. Towards real-world biological data, we evaluate the performance of our approach over in silico numerical datasets based on a real and large-scale prior knowledge network. The correctness of our encoding and discretization schemes are dealt with in Appendices A-B. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Answer set programming
KW  - Signaling transduction networks
KW  - Boolean logic models
KW  - Combinatorial multi-objective optimization
KW  - Systems biology
Y1  - 2015
U6  - https://doi.org/10.1016/j.tcs.2014.06.022
SN  - 0304-3975
SN  - 1879-2294
VL  - 599
SP  - 79
EP  - 101
PB  - Elsevier
CY  - Amsterdam
ER  -