@article{SarsakovSchaubTompitsetal.2004, author = {Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {A compiler for nested logic programming}, isbn = {3-540- 20721-x}, year = {2004}, language = {en} } @article{DelgrandeSchaubTompitsetal.2004, author = {Delgrande, James Patrick and Schaub, Torsten H. 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{KonczakLinkeSchaub2004, author = {Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.}, title = {Graphs and cologings for answer set programming : adridged report}, isbn = {3-540- 20721-x}, year = {2004}, language = {en} } @article{BoeselLinkeSchaub2004, author = {Boesel, Andreas and Linke, Thomas and Schaub, Torsten H.}, title = {Profiling answer set programming : the visualization component of the noMoRe System}, isbn = {3-540-23242-7}, year = {2004}, language = {en} } @article{BorchertAngerSchaubetal.2004, author = {Borchert, P. and Anger, Christian and Schaub, Torsten H. and Truszczynski, M.}, title = {Towards systematic benchmarking in answer set programming : the dagstuhl initiative}, isbn = {3-540- 20721-x}, year = {2004}, language = {en} } @article{DelgrandeSchaub2004, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {Two approaches to merging knowledge bases}, isbn = {3-540-23242-7}, year = {2004}, language = {en} } @article{DelgrandeSchaubTompits2004, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {Domain-specific preference for causal reasoning and planning}, isbn = {1-577-35201-7}, year = {2004}, language = {en} } @article{FloeterSelbigSchaub2004, author = {Fl{\"o}ter, Andr{\´e} and Selbig, Joachim and Schaub, Torsten H.}, title = {Finding metabolic pathways in decision forests}, isbn = {3-540-23221-4}, year = {2004}, language = {en} } @article{DelgrandeSchaub2004, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {Consistency-based approaches to merging knowledge based : preliminary report}, isbn = {92-990021-0-X}, year = {2004}, language = {en} } @article{FloeterNicolasSchaubetal.2004, author = {Fl{\"o}ter, Andr{\´e} and Nicolas, Jacques and Schaub, Torsten H. 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{DelgrandeSchaubTompitsetal.2004, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Wang, Kewen}, title = {A classification and survey of preference handling approchaches in nonmonotonic reasoning}, issn = {0824-7935}, year = {2004}, abstract = {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}, language = {en} } @article{DelgrandeSchaub2004, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {Reasoning with sets of preferences in default logic}, issn = {0824-7935}, year = {2004}, abstract = {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}, language = {en} }