The Price of Query Rewriting in Ontology-Based Data Access
We give a solution to the succinctness problem for the size of first-order rewritings of conjunctive queries in ontologybased data access with ontology languages such as OWL2QL, linear Datalog and sticky Datalog. We show that positive existential and nonrecursive datalog rewritings, which do not use extra non-logical symbols (except for intensional predicates in the case of datalog rewritings), suer an exponential blowup in the worst case, while first-order rewritings can grow superpolynomially unless NP in P/poly. We also prove that nonrecursive datalog rewritings are in general exponentially more succinct than positive existential rewritings, while first-order rewritings can be superpolynomially more succinct than positive existential rewritings. On the other hand, we construct polynomial-size positive existential and nonrecursive datalog rewritings under the assumption that any data instance contains two fixed constants.
In this paper authors wish to present an approach to information modeling and software design suitable for developing evolvable semantic applications in the domain of research team formation. The novel proposals include specialization of generic paradigm of ontological engineering, specific types of machine-readable RDF ontologies and application of temporal look at information relevant for team formation. In order to validate theoretical approach a software prototype of the evolvable web-based semantic platform InfoPort was developed.
It turns out, however, that in spite of one basic difference there runs between these two systems a deep and striking parallelism. This parallelism is so close indeed that it makes possible the construction of a vocabulary which would transform characteristic propositions of Wittgenstein's ontology into Aristotelian ones, and conversely. To show in some detail the workings of that transformation will be the subject of this paper.
It is difficult to imagine an enterprise, company, firm, an education organizations or organizations of health which does not deal with information systems. The openness and flexibility of the information systems provide a flexible and effective management. So it is necessary to adapt information system to new conditions being changed and to team up with other systems, with simulation system, for example. So it is possible change business processes, to execute their reengineering and to anticipate the conse-quences of any event and to take into account the different risks.
We describe a novel method for the analysis of research activities of an organization by mapping that to a taxonomy tree of the field. The method constructs fuzzy membership profiles of the organizationmembers or teams in terms of the taxonomy’s leaves (research topics), and then it generalizes them in two steps. These steps are: (i) fuzzy clustering research topics according to their thematic similarities in the department, ignoring the topology of the taxonomy, and (ii) optimally lifting clusters mapped to the taxonomy tree to higher ranked categories by ignoring “small” discrepancies. We illustrate the method by applying it to data collected by using an in-house e-survey tool from a university department and from a university research center. The method can be considered for knowledge generalization over any taxonomy tree.
Збірка наукових праць
The article considers the conceptual approach of creating a set of development tools for active learning methods in a form of competency-based business-game studio. Competence-based business game is an information system, which aims to give a certain level of professional competence while implementing scenarios that are determined by business-process models of the domain. The structure of the gaming studio, suggests a set-theoretic representation of business-game design process. Business game can be represented as a cybernetic system with feedback, which contains both the object of management and the management system. The game is implemented as control and operating machines accordingly. For the construction of the operational machine it is proposed to use a knowledge model in the form of ontology. To represent the automate model it is proposed to use a model of managing business processes of an enterprise. A block diagram of the business-game design process is provided.
In this work the problem of learning and development of creativity with a view to the position of reflexive psychology, akmeology and pedagogics in the context of the human capital analysis in the conditions of modern society globalization is raised. The theme is urgent from the practical point of view in demand of a creative personality under conditions of the economic crisis and at the same time it is actual, because it interprets creativity in a new way according to interdisciplinary approach. The author emphasizes that a reflexively-creative potential is considered to be the backbone factor of professional and innovative activity in modern social space. On basis of philosophical foundations' analysis of psychology of creativity we theoretically build the conceptual model of reflexive creativity and we also examine the precedents of its psychology-pedagogical development in the secondary and high education (in case of reflexive-psycological support).
We consider certain spaces of functions on the circle, which naturally appear in harmonic analysis, and superposition operators on these spaces. We study the following question: which functions have the property that each their superposition with a homeomorphism of the circle belongs to a given space? We also study the multidimensional case.
We consider the spaces of functions on the m-dimensional torus, whose Fourier transform is p -summable. We obtain estimates for the norms of the exponential functions deformed by a C1 -smooth phase. The results generalize to the multidimensional case the one-dimensional results obtained by the author earlier in “Quantitative estimates in the Beurling—Helson theorem”, Sbornik: Mathematics, 201:12 (2010), 1811 – 1836.
We consider the spaces of function on the circle whose Fourier transform is p-summable. We obtain estimates for the norms of exponential functions deformed by a C1 -smooth phase.