It is hypothesized that creativity arises from the self-mending capacity of an internal model of the world, or worldview. The uniquely honed worldview of a creative individual results in a distinctive style that is recognizable within and across domains. It is further hypothesized that creativity is domaingeneral in the sense that there exist multiple avenues by which the distinctiveness of one's worldview can be expressed. These hypotheses were tested using art students and creative writing students. Art students guessed significantly above chance both which painting was done by which of five famous artists, and which artwork was done by which of their peers. Similarly, creative writing students guessed significantly above chance both which passage was written by which of five famous writers, and which passage was written by which of their peers. These findings support the hypothesis that creative style is recognizable. Moreover, creative writing students guessed significantly above chance which of their peers produced particular works of art, supporting the hypothesis that creative style is recognizable not just within but across domains.

We present a knowledge representation framework with an associated run-time support infrastructure that is able to compute, for the benefit of the members of a norm-governed multi-agent system, physically possible and/or permitted actions current at each time, as well as sanctions that should be applied to violations of prohibitions. Experimental results on a benchmark scenario indicate how by distributing norms we can provide run-time support to large-scale, norm-governed multi-agent systems.

Since argumentation is an inherently dynamic process, it is of great importance to understand the effect of incorporating new information into given argumentation frameworks. In this work, we address this issue by analyzing equivalence between argumentation frameworks under the assumption that the frameworks in question are incomplete, i.e. further information might be added later to both frameworks simultaneously. In other words, instead of the standard notion of equivalence (which holds between two frameworks, if they possess the same extensions), we require here that frameworks F and G are also equivalent when conjoined with any further framework H. Due to the nonmonotonicity of argumentation semantics, this concept is different to (but obviously implies) the standard notion of equivalence. We thus call our new notion strong equivalence and study how strong equivalence can be decided with respect to the most important semantics for abstract argumentation frameworks. We also consider variants of strong equivalence in which we define equivalence with respect to the sets of arguments credulously (or skeptically) accepted, and restrict strong equivalence to augmentations H where no new arguments are raised.

Handling exceptions in a knowledge-based system has been considered as an important issue in many domains of applications, such as medical domain. In this paper, we propose several preferential semantics for plausible subsumption to deal with exceptions in description logic-based knowledge bases. Our preferential semantics are defined in the framework of possibility theory, which is an uncertainty theory devoted to the handling of incomplete information. We consider the properties of these semantics and their relationships. Entailment of these plausible subsumption relative to a knowledge base is also considered. We show the close relationship between two of our semantics and the mutually dual preferential semantics given by Britz, Heidema and Meyer. Finally, we show that our semantics for plausible subsumption can be reduced to standard semantics of an expressive description logic. Thus, the problem of plausible subsumption checking under our semantics can be reduced to the problem of subsumption checking under the classical semantics.

We propose a new family of probabilistic description logics (DLs) that, in contrast to most existing approaches, are derived in a principled way from Halpern's probabilistic first-order logic. The resulting probabilistic DLs have a two-dimensional semantics similar to certain popular combinations of DLs with temporal logic and are well-suited for capturing subjective probabilities. Our main contribution is a detailed study of the complexity of reasoning in the new family of probabilistic DLs, showing that it ranges from PTime for weak variants based on the lightweight DL EL to undecidable for some expressive variants based on the DL ALC.

We present a framework for reasoning about actions that not only solves the frame and ramification problems, but also the state default problem—the problem to determine what normally holds at a given time point. Yet, the framework is general enough not to be tied to a specific time structure. This is achieved as follows: We use effect axioms that draw ideas both from Reiter's successor state axioms and the non-monotonic causal theories by Giunchiglia et al. These axioms are formulated in a recently proposed unifying action calculus to guarantee independence of a specific underlying notion of time. Reiter's default logic is then wrapped around the resulting calculus and plays a key role in solving the ramification as well as the state default problem.

There is currently a growing interest in techniques for hiding parts of the signature of an ontology Kh that is being reused by another ontology Kv. Towards this goal, Cuenca Grau, Motik, and Kazakov (2009) recently proposed the import-by-query framework, which makes the content of Kh accessible through a limited query interface. If Kv reuses the symbols from Kh in a certain restricted way, one can reason over Kv U Kh by accessing only Kv and the query interface. In this paper, we map out the landscape of the import-by-query problem. We show that certain restrictions of our original framework are strictly necessary to make reasoning possible, we propose extensions that overcome some of the expressivity limitations, we present several novel reasoning algorithms, and we outline the limitations of the new framework.

Cardinality constraints or, more generally, weight constraints are well recognized as an important extension of answer-set programming. Clearly, all common algorithmic tasks related to programs with cardinality or weight constraints (PWCs) - like checking the consistency of a program - are intractable. Many intractable problems in the area of knowledge representation and reasoning have been shown to become tractable if the treewidth of the programs or formulas under consideration is bounded by some constant. The goal of this paper is to apply the notion of treewidth to PWCs and to identify tractable fragments. It will turn out that the straightforward application of treewidth to PWCs does not suffice to obtain tractability. However, by imposing further restrictions, tractability can be achieved.

We provide two approaches for explaining inconsistency in multi-context systems, where decentralized and heterogeneous system parts interact via nonmonotonic bridge rules. Inconsistencies arise easily in such scenarios, and nonmonotonicity calls for specific methods of inconsistency analysis. Both our approaches characterize inconsistency in terms of involved bridge rules: either by pointing out rules which need to be altered for restoring consistency, or by finding combinations of rules which cause inconsistency. We show duality and modularity properties, give precise complexity characterizations, and provide algorithms for computation using HEX-programs. Our results form a basis for inconsistency management in heterogeneous knowledge integration systems.

In particular, I will explain how the complexity scheduling, planning, graph problems, among others. The landscape differs for traditional reasoning and for query most well-known constraint satisfaction problem is propositional answering, and take a brief look at computational complexity satisfiability SAT. Of particular recent interest is satisfiability issues raised by implementations of DL query answering modulo theories (SMT), where the interpretation based on standard relational database systems. Throughout of some symbols is constrained by a background theory. For the tutorial, connections to the W3C-standard OWL are example, the theory of arithmetic restricts the interpretation drawn whenever possible. of symbols such as:,, 0, and 1. SMT draws on the most prolific problems in the past century What If You Wanted Someone (Else) to Use This?