The University of Ostrava is situated in the city of Ostrava, Moravian-Silesian Region, Czech Republic. Founded in 1991, it is the youngest public university in Ostrava. It consists of six faculties and two institutes providing university education. Wikipedia.
Kupka J.,University of Ostrava
Information Sciences | Year: 2011
Let X denote a locally compact metric space and : X → X be a continuous map. In the 1970s Zadeh presented an extension principle helping us to fuzzify the dynamical system (X, ), i.e., to obtain a map Φ for the space of fuzzy sets on X. We extend an idea mentioned in [P. Diamond, A. Pokrovskii, Chaos, entropy and a generalized extension principle, Fuzzy Sets Syst. 61 (1994) 277-283] to generalize Zadeh's original extension principle. In this paper we study basic properties of so-called g-fuzzifications, such as their continuity properties. We also show that, for any g-fuzzification: (i) a uniformly convergent sequence of uniformly continuous maps on X induces a uniformly convergent sequence of fuzzifications on the space of fuzzy sets and (ii) a conjugacy (resp., a semi-conjugacy) between two discrete dynamical systems can be extended to a conjugacy (resp., a semi-conjugacy) between fuzzified dynamical systems. Throughout this paper we consider different topological structures in the space of fuzzy sets, namely, the sendograph, endograph and levelwise topologies. © 2011 Elsevier Inc. All rights reserved.
Silhan K.,University of Ostrava
Geomorphology | Year: 2014
High-gradient channels are the locations of the greatest geomorphological activity in medium-high mountains. The channels' frequency and character influence the contemporary morphology and morphometry of alluvial fans. There is currently no detailed information regarding the frequency of these processes in high-gradient channels and the evolution of alluvial fans in medium-high mountains in Central Europe. This study in the Moravskoslezské Beskydy Mts. analysed 22 alluvial fans (10 debris flow fans and 12 fluvial fans). The processes occurring on the fans were dated using dendrogeomorphological methods. A total of 748 increment cores were taken from 374 trees to reconstruct 153 geomorphological process events (60 debris flow and 93 floods). The frequency of the processes has been considerably increasing in the last four decades, which can be related to extensive tree cutting since the 1970s. Processes in high-gradient channels in the region (affecting the alluvial fans across the mountain range) are predominantly controlled by cyclonal activity during the warm periods of the year. Probable triggers of local events are heavy downpours in the summer. In addition, spring snowmelt has been identified as occasionally important. This study of the relations affecting the type and frequency of the processes and their effect on the properties of alluvial fans led to the creation of a universal framework for the medium-high flysch mountains of Central Europe. The framework particularly reflects the influence of the character of hydrometeorological extremes on the frequency and type of processes and their reflection in the properties of alluvial fans. © 2013 Elsevier B.V.
Lata J.,University of Ostrava
World Journal of Gastroenterology | Year: 2012
Hepatorenal syndrome (HRS) is defined as a functional renal failure in patients with liver disease with portal hypertension and it constitutes the climax of systemic circulatory changes associated with portal hypertension. This term refers to a precisely specified syndrome featuring in particular morphologically intact kidneys, where regulatory mechanisms have minimised glomerular filtration and maximised tubular resorption and urine concentration, which ultimately results in uraemia. The syndrome occurs almost exclusively in patients with ascites. Type 1 HRS develops as a consequence of a severe reduction of effective circulating volume due to both an extreme splanchnic arterial vasodilatation and a reduction of cardiac output. Type 2 HRS is characterised by a stable or slowly progressive renal failure so that its main clinical consequence is not acute renal failure, but refractory ascites, and its impact on prognosis is less negative. Liver transplantation is the most appropriate therapeutic method, nevertheless, only a few patients can receive it. The most suitable "bridge treatments" or treatment for patients ineligible for a liver transplant include terlipressin plus albumin. Terlipressin is at an initial dose of 0.5-1 mg every 4 h by intravenous bolus to 3 mg every 4 h in cases when there is no response. Renal function recovery can be achieved in less than 50% of patients and a considerable decrease in renal function may reoccur even in patients who have been responding to therapy over the short term. Transjugular intrahepatic portosystemic shunt plays only a marginal role in the treatment of HRS. © 2012 Baishideng. All rights reserved.
Novak V.,University of Ostrava
Fuzzy Sets and Systems | Year: 2012
This paper is devoted to reasoning about fuzzy logic which is based on various personal observations of the author. Our goal is to think of the state of the art in mathematical fuzzy logic (MFL) and to outline some of the tasks on which, in the author's opinion, MFL should focus in the future. In our discussion, we will mention not only the basic theory, but also its extension called fuzzy logic in broader sense (FLb). The paradigm of the latter is to be the logic of natural human reasoning, whose most essential characteristic is the use of natural language. Besides brief description of FLb, we will also mention some of its applications. On the basis of that, we will ponder on other possible directions for research, namely the possibility of using FLn as a metatheory of fuzzy mathematics, as a proper tool for modeling of the main manifestations of the phenomenon of vagueness, and as a reasonable tool for developing models of linguistic semantics. © 2010 Elsevier B.V. All rights reserved.
Perfilieva I.,University of Ostrava
Information Sciences | Year: 2013
In this paper, we consider the problem of solving systems of fuzzy relation equations. Two types of these systems with different compositions are considered and processed simultaneously. A new sufficient condition and new solvability criteria are proposed for systems of both types. All these conditions are finitary and thus can be easily verified. The sufficient condition and criteria of solvability characterize a relationship between a skeleton n × n matrix (n is a number of equations) and a vector of the right-hand side. © 2011 Elsevier Inc. All rights reserved.