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Regularity criteria for instationary incompressible Navier-Stokes equations
Axmann, Šimon ; Pokorný, Milan (advisor) ; Neustupa, Jiří (referee)
Title: Regularity criteria for instationary incompressible Navier-Stokes equations Author: Šimon Axmann Institute: Mathematical Institute of Charles University Supervisor: doc. Mgr. Milan Pokorný, Ph.D., Mathematical Institute of Charles University Abstract: In the present thesis we study the global conditional regularity of weak solutions to the Cauchy problem for instationary incompressible Navier-Stokes equations in three space dimensions. In the first section, we present an overview of known conditions implying the full regularity of the equations under conside- ration. For the sake of clarity, we expose only the regularity criteria on the scale of Lebesgue spaces, especially in terms of the velocity and its components, the gradient of the velocity and its components, the pressure and the vorticity. In the subsequent sections, we generalize four regularity criteria using two different techniques. We are able to replace one velocity component or its gradient, consi- dered in the known results, by a projection of the velocity into a general vector field. For the purpose of the second method, we also generalize the multiplicative Gagliardo-Nirenberg inequality.
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Compressible fluid motion in time dependent domains
Sýkora, Petr ; Feireisl, Eduard (advisor) ; Pokorný, Milan (referee)
In this work we study the existence of weak solutions for compressible Navier-Stokes equations in unbounded time dependent domains. Using the methods introduced in Feireisl E. Dynamics of Viscous Compressible Fluids we extend the results of article Feireisl E. Neustupa J. Stebel J., Convergence of a Brinkman-type penalization for compressible fluid flows, which studies the flow with a "no-slip" boundary condition on bounded domains. Next, we extend results of article Feireisl E. Kreml O. Nečasová Š. Neustupa J. Stebel J., Weak solutions to the barotropic Navier- Stokes system with slip boundary conditions in time dependent domains, which studies flow with compete Navier boundary condition. Finally, we discuss solutions for rotating fluid system. In this case, there are new members in momentum equation, representing the Coriolis and centrifugal force, which cause problems.
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The expressiveness of experience: a structural and phenomenological account of the Russian formalists' "aesthetic of estrangement"
Flack, Patrick ; Vojvodík, Josef (advisor) ; Kubíček, Tomáš (referee) ; Pokorný, Martin (referee)
In their seminal studies in literary theory and poetics, the Russian formalists (Šklovskij, Tynjanov, Jakobson, etc.) famously claim that aesthetic experience amounts to a self-valuable, concrete act of perception functionally induced and conditioned by the formal structure of a work of art or literature. This aesthetic principle, christened by Šklovskij as "estrangement" (ostranenie), played an instrumental role in the formalists' contribution to the establishment and development of literary theory as an autonomous scientific discipline. It has also regularly inspired other thinkers and provided the impetus for productive new insights on art or literature, a fact that seems to underline its acuity and relevance. At the same time however, the formalists' "strange" account of art and literature has been routinely disparaged for being altogether inadequate, philosophically flimsy and descriptively too narrow. Critics have pointed out that the formalists' assertions on the topic of perception rest but on a set of ad hoc psychological hypotheses and are overly determined by their specific scientific aims and modernist prejudices. Worse, the principle of estrangement has been credibly attacked for being semiotically naïve and for stripping art and literature of any "content" or meaning, to say nothing...
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The illusive world. Dreaming and seeming in selected modern texts
Izdná, Petra ; Pokorný, Martin (advisor) ; Vojvodík, Josef (referee)
The thesis aims at the interpretation of the several Early Modern literature masterpieces through the theme of the illusive world. The literary comparison of such diverse works as William Shakespeares romances, Calderóns play and allegorical novels of Comenius or Baltasar Gracián unveils some common features. The analysis of numerous motives of dreaming and deception and of the traditional topoi "life is a dream" and "the world is a theatre" illustrates the feelings of delusion and insecurity as well as a spiritual desire for the transcendence at the Baroque period.
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Transformations of the US Foreign Policy
Pokorný, Martin ; Barša, Pavel (advisor) ; Jireš, Jan (referee)
Transformation of the US Foreign Policy Diploma thesis "Transformation of the US Foreign Policy" consists changes and tranformations in the US foreign policy connected with alternations of president's administratives. Especially with the alternation in 2001, when Goerge W. Bush supplied Bill Clinton and than with 2009 when Barack Obama became president of the USA. My essential resource were special books about US foreign policy. Thereafter books from the field of theory of international relations and finally I used internet resources as special articles or manifests records. Diploma thesis is focused on foreign and security policy. Arise and progress of the USA shaped American identity. Hypothesis of work is connected with issue that even conducts and acts of administratives could be different, policy always following this American self-identity.
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Mathematical Analysis of Models for Viscoelastic Fluids
Kreml, Ondřej ; Pokorný, Milan (advisor) ; Skalák, Zdeněk (referee) ; Neustupa, Jiří (referee)
1 Title: Mathematical analysis of models for viscoelastic fluids Author: Ondřej Kreml Department: Mathematical Institute of Charles University Supervisor: Doc. Mgr. Milan Pokorný, Ph.D. Abstract: We consider several problems in the thesis. First we summarize key ideas of fluid mechanics theory and introduce several models describ- ing nonnewtonian behaviour of fluids. In the second chapter we prove local existence of solutions to the Oldroyd-type system achieved as a limit case with infinite relaxation and retardation times. We work with three types of boundary conditions, namely homogenous Dirichlet and periodic conditions and whole space, in 2D and 3D. We study also related system of PDE's which is equivalent to the Oldroyd-type system in 2D. In the third chapter we prove local existence of solutions to the system of PDE's describing the flow of a polymeric liquid. The polymer molecules are modeled as elastic dumbbells with spring force having the so-called FENE potential. Arising system con- sists of Navier-Stokes equations coupled with Fokker-Planck equation. In the fourth chapter we study asymptotic behaviour of solutions to equations desribing steady flow of a second grade fluid past an obstacle in three dimen- sions with prescribed nonzero velocity at infinity. Key point in the proof is using results of...
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Multimedia Overview of Synoptic Meteorology
Pokorný, Michal ; Žák, Michal (advisor) ; Bednář, Jan (referee)
This diploma thesis contains an overview of the synoptic meteorology, from the so called Norwegian meteorological school and its interlacing with more modern concepts. It deals with air masses, atmospheric fronts and pressure systems. Further, the overview of latter conceptual models of atmospheric fronts is presented. It shows using of satellite and radar measurements in synoptical praxis, as well. The first chapter introduces formation of air masses and apportionment of air masses. It notices transformation of air masses, too. The second chapter deals with basic clasification of atmospheric fronts. Fronts are shown with help of satelite and radar images. Creation and development of pressure systems follows.
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Mathematical Analysis of Fluids in Large Domains
Poul, Lukáš ; Feireisl, Eduard (advisor) ; Pokorný, Milan (referee) ; Vodák, Rostislav (referee)
This thesis contains a set of articles concerned with flow of a viscous, compressible and heat conducting fluid in large domains. In the first part of the thesis, the existence of the weak solutions in unbounded domains is studied. The results follow each other in the way they were obtained through the time, and range from a simple extension to bounded domains with Lipschitz boundary up to the most general existence theorem for fluid flow in general open sets. The existence results are supplemented with the study of existence of weak solutions in the unbounded domain case with prescribed nonvanishing boundary conditions for density and temperature at infinity. The last contribution then concerns with the low Mach number limit in the compressible fluid flow.
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The phenomenon of fiction
Koblížek, Tomáš ; Petříček, Miroslav (referee) ; Pokorný, Martin (advisor)
The subject of the work is the problem of the fictionality of literary texts. The work is divided into three parts. The first part deals with the nature of poetic language. The central thesis is that literature cannot be perceived as a set of objective attributes of a given statement but as the way utterance affects the reader, that is, as a phenomenon. This assumption allows us to define fictionality tentatively as a phenomenon or as an aspect of the phenomenon of literature. The second part introduces a critique of the theory of fictional world. The objections are concerned with the concept of the world as an aggregate of objects, characters and events, relation between the texture and the fictional world viewed as mediating representation, the concept of literary creation as a translating of extensional plane to the intensional one, and the concept of reading as the reconstruction of fictional objects. The third part suggests an answer to the problem of the fictionality. Considering Patočka's essay Učení o minulém rázu umění the phenomenon of literature is defined as the flowing of objective component of experience into the non-objective one. The fictional object is thus conceived as the vanishing object in the sense of its becoming the non-object.
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Towards an Eco-inspired poetics of minimalist narrative
Kuzmičová, Anežka ; Pokorný, Martin (referee) ; Bílek, Petr (advisor)
What is a minimalist narrative, and what are its characteristic features? How do you identify one? For many critics, minimalist writing is a strictly historical notion - even though they at the same time, like John Barth does in his famous apologetics "A Few Words About Minimalism", paradoxically enough stress its ubiquitous nature throughout literature of all times. By narrative minimalism the American critic generally means the austere style of the novels and short stories of Raymond Carver, Amy Hempel, Mary Robison, Joan Didion, Ann Beattie. An American literary current of the 1970s mainly, devoted merely to the quotidian, descriptive, often reduced to what can be perceived from the outside of a human character. Thereby: the "dirty realism" or "K-mart realism". These derogatory labels tell us that the literary reviewer and critic of today still formulates his terms and judgments out of a hierarchically ordered, traditional presupposition of what a narrative text is and should be, working with a virtual model of balance between "form" and "content". Translated into the language of classical narratology: story discourse.
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