Wydział Fizyki Technicznej, Informatyki i Matematyki Stosowanej (W7) / Faculty of Technical Physics, Information Technology and Applied Mathematicshttp://hdl.handle.net/11652/72017-07-04T10:21:51Z2017-07-04T10:21:51Zσ-porous sets of generalised nonexpansive mappingsStrobin, Filiphttp://hdl.handle.net/11652/11582016-07-15T01:00:40Z2014-01-01T00:00:00Zσ-porous sets of generalised nonexpansive mappings
Strobin, Filip
In the paper we show that many generic results obtained in the last 40 years in the field of fixed point theory, are consequences of one general theorem. As an application we get some extensions of them and we study the generic aspect of the existence of attractors of nonexpansive IFSs. We also give a detailed discussion on the relationship between two results obtained by De Blasi and Myjak, and Reich and Zaslavski.
2014-01-01T00:00:00ZSelected aspects of security mechanisms for cloud computing – current solutions and development perspectivesPoniszewska-Marańda, Anetahttp://hdl.handle.net/11652/11232016-07-11T12:54:29Z2014-01-01T00:00:00ZSelected aspects of security mechanisms for cloud computing – current solutions and development perspectives
Poniszewska-Marańda, Aneta
The security aspects of cloud computing, especially the security of data, become more and more important. It is necessary to find and develop the new mechanisms to secure the cloud. The problem presented in the paper concerns the mechanisms for security of cloud computing with special attention paid to aspects of access control in clouds – the state of the art and the perspectives for the future.
2014-01-01T00:00:00ZProper conformal symmetries in self-dual Einstein spacesChudecki, AdamDobrski, Michałhttp://hdl.handle.net/11652/11152016-03-24T02:01:24Z2014-01-01T00:00:00ZProper conformal symmetries in self-dual Einstein spaces
Chudecki, Adam; Dobrski, Michał
Proper conformal symmetries in self-dual Einstein spaces are considered. It is shown that such symmetries are admitted only by the Einstein spaces of the type [N,−]⊗[N,−][N,−]⊗[N,−] . Spaces of the type [N]⊗[−][N]⊗[−] are considered in details. Existence of the proper conformal Killing vector implies existence of the isometric, covariantly constant, and null Killing vector. It is shown that there are two classes of [N]⊗[−][N]⊗[−] -metrics admitting proper conformal symmetry. They can be distinguished by analysis of the associated anti-self-dual (ASD) null strings. Both classes are analyzed in details. The problem is reduced to single linear partial differential equation (PDE). Some general and special solutions of this PDE are presented.
2014-01-01T00:00:00ZOscillatory properties of solutions of the fourth order difference equations with quasidifferencesJankowski, RobertSchmeidel, EwaZonenberg, Joannahttp://hdl.handle.net/11652/11082016-03-24T02:00:59Z2014-01-01T00:00:00ZOscillatory properties of solutions of the fourth order difference equations with quasidifferences
Jankowski, Robert; Schmeidel, Ewa; Zonenberg, Joanna
A class of fourth-order neutral type difference equations with quasidifferences and deviating arguments is considered. Our approach is based on studying the considered equation as a system of a four-dimensional difference system. The sufficient conditions under which the considered equation has no quickly oscillatory solutions are given. Finally, the sufficient conditions under which the equation is almost oscillatory are presented.
2014-01-01T00:00:00Z