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Factors causing spatial distribution of ant nest
Zeman, Jiří ; Frouz, Jan (advisor) ; Holec, Michal (referee)
We observed the distribution in the large complex of the interrelated nests of Formica polyctena ant species on the locality Polánka near Mladá Vožice. In GIS we studied which factors affect spatial distribution of the F. polyctena anthills via diskriminant analysis. Totally we maped 244 nests. The main factors affecting the distribution of ant nests are existence of open areas in the forest (paths and openings) and the position of another anthills. The anthills indicate the cluster spacing. Anthills in the openings are smaller than those in the highwood.
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Goal-oriented a posteriori error estimates and adaptivity for the numerical solution of partial differential equations
Roskovec, Filip ; Dolejší, Vít (advisor) ; Kanschat, Guido (referee) ; Zeman, Jan (referee)
A posteriori error estimation is an inseparable component of any reliable numerical method for solving partial differential equations. The aim of the goal-oriented a posteriori error estimates is to control the computational error directly with respect to some quantity of interest, which makes the method very convenient for many engineering applications. The resulting error estimates may be employed for mesh adaptation which enables to find a numerical approximation of the quantity of interest under some given tolerance in a very efficient manner. In this thesis, the goal-oriented error estimates are derived for discontinuous Galerkin discretizations of the linear scalar model problems, as well as of the Euler equations describing inviscid compressible flows. It focuses on several aspects of the goal-oriented error estimation method, in particular, higher order reconstructions, adjoint consistency of the discretizations, control of the algebraic errors arising from iterative solutions of both algebraic systems, and linking the estimates with the hp-anisotropic mesh adaptation. The computational performance is demonstrated by numerical experiments.
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Variational Methods in Thermomechanics of Solids
Pelech, Petr ; Kružík, Martin (advisor) ; Dondl, Patrick (referee) ; Zeman, Jan (referee)
The thesis is devoted to study of continuum mechanics and thermodynamics and the related mathematical analysis. It consists of four self-contained chapters dealing with different aspects. The first chapter focuses on peridynamics, a non-local theory of continuum mechanics, and its relation to conventional local theory of Cauchy-Green elasticity. Similar compar- isons has been used for proving consistency and for determining some of the material coefficients in peridynamics, provided the material parameters in the local theory are known. In this chapter the formula for the non-local force-flux is computed in terms of the peridynamic interaction, relating the fundamental concepts of these two theories and establishing hence a new connection, not present in the previous works. The second and third chapters are both devoted to Rate-Independent Systems (RIS) and their applications to continuum mechanics. RIS represents a suitable approximation when the internal, viscous, and thermal effects can be neglected. RIS has been proven to be useful in modeling hysteresis, phase transitions in solids, elastoplasticity, damage, or fracture in both small and large strain regimes. In the second chapter the existence of solutions to an evolutionary rate-independ- ent model of Shape Memory Alloys (SMAs) is proven. The model...
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Relaxace v mechanice kontinua tuhé fáze
Pathó, Gabriel ; Kružík, Martin (advisor) ; Zeman, Jan (referee)
This work deals with the modelling of shape-memory alloys, in particular with the steady-state model of martensitic thin films. After the introductory motivation the crystallographic structure of the materials is described followed by the introduction of the link between the lattice and continuum model. The next parts of the work focus on the possible solutions of the given 3D variational problem (quasiconvexification, Young measures) and on derivation of thin film theories with the aid of different tools (regularization,-convergence). The last part takes over an approximation of an obtained model and sketches numerical experiments on a Ni-Mn-Ga alloy.
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Geochemical study of processes, relevant to safety assessment of deep geological repository: Uranium forms and enrichment scenario in a sedimentary system at the Ruprechtov natural analogue site
Havlová, Václava ; Jelínek, Emil (advisor) ; Pačes, Tomáš (referee) ; Zeman, Josef (referee)
U migration was studied in order to better understand to processes of safety relevant elements, particularly U. The rock sequence on the site can be analogous to a potential rock overburden of deep geology repositories. A multidisciplinary approach was undertaken in order to identify and characterise U mobilisation/immobilisation processes within sedimentary clayey rocks with organic matter enriched interlayers. Both conventional methods and modern sophisticated spectroscopic methods were combined. Sequential extraction, wet chemical method and even spectroscopic methods proved that U prevailed in the U(IV) form in low-oxidised samples. It moved towards more easily releasable fractions with sample ageing (oxidation). The combination of SE, µ-XRF and µ-XAFS results proved U to be unexpectedly associated with As and P, leading to the presumption that U(VI) from groundwater was reduced to U(IV) on As pyrite. The evaluation of the hydrogeochemical conditions and isotope analyses then brought the results into broader context: Sedimentary organic matter within the sedimentary layers was microbially oxidised, releasing dissolved organic matter and providing H+ in order to dissolve sedimentary inorganic carbonates. SO4 2- could be reduced under reducing groundwater conditions, thus causing FeS2 formation....
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Biological effects of shock waves generated by multichannel discharge
Zeman, Jan ; Beneš, Jiří (advisor) ; Šunka, Pavel (referee)
Shock waves are generally characterized by a sharp change of the pressure, which causes subsequent changes in properties of the surrounding in which it spreads. In medical applications, it is an acoustic shock wave which is used for the treatment of concrements for more than 25 years. This success naturally led to considerations about the possibility of using shock waves in other areas of medicine. One of the main directions of the research is the possibility of the damage to tumor tissue. In contrast to concrements the tumor tissue is not different from surrounding tissues by its acoustic attributes, so the normal lithotryptor is not appropriate for this application. Therefore, there has been developed a new source of shock waves, which is based on the principle of multichannel discharge on the composite anode. The experiments demonstrated the effect of the new source on the acoustically homogeneous tissue of the thigh muscle at a depth of rabbit in vivo. Then there was observed the damage to tumor tissue in vivo in rats. Finally, there was observed the damage to tumor tissue in vivo in rats in the combination with cisplatin and Photosan. It was found that the new source of shock waves can cause the damage to the acoustically homogeneous tissue in vivo in depth. It also can damage the tumor...
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Sequential and Prosodic Aspects of Conversation
Havlík, Martin ; Nekvapil, Jiří (advisor) ; Volín, Jan (referee) ; Zeman, Jiří (referee)
This study deals with two phenomena which are closely related to the turn-taking mechanism in conversation. These are: overlapping talk and the use of prosody in turn-taking. Prosody is linked to the formation of the transition relevance place. I point out the aspects of conversation, including prosody, which shape the transition relevance place, and also how prosody is used in the projection of turn-yielding, or turn-holding. I devote attention to three basic aspects of prosody: pitch movement, intensity movement and articulation rate. Furthermore, I analyze how overlapping turns are produced, how they proceed and how they are resolved. The characteristics of overlapping talk are influenced by the types of conversation in which they occur: while in mundane, informal conversation they can last only briefly, usually produced as a means of mutual understanding, in political debates they are often prolonged, as they are associated with the efforts of speakers to take and hold the floor.
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The definition of the Slovak-Hungarian borderland in terms of socio-cultural aspects and evaluation of their impact on cross-border cooperation in selected areas of interest
Zeman, Juraj ; Chromý, Pavel (advisor) ; Jeřábek, Milan (referee)
The master thesis deals with a theme of a definition of the Slovak-Hungarian borderland, which we specify on the basis of socio-cultural aspects and evaluation of cross-border cooperation in selected areas of interest by controlled interview with the heads of the local self-government. The thesis consists of four parts. A content of the first part is a discussion of the used expressions border, socio-cultural aspects, borderland, cross-border cooperation, and theoretical and methodological framing of issues. The second part aims to explain a historical development of the Slovak-Hungarian borderland. It is essential to understand the historical context that influenced the borderland and its population. The third part of the thesis focuses on an issue of the borderland definition on the basis of socio-cultural aspects, particularly nationality, religion, natives during the 20th century. Moreover, the thesis deals with a definition of three selected borderland areas of interest, which assesses the socio-cultural aspects afterwards. The fourth part of the thesis focuses on a cross-border cooperation in the areas of interest. To evaluate the cross border cooperation, a method of controlled interview was used, made with the heads of the local self-government. This subjective evaluation gives us a real...
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Architectural and urban developement of Liberec 1352-2006
Zeman, Jaroslav ; Macek, Petr (advisor) ; Horyna, Martin (referee)
Liberec a relatively young city is compared to with the majority of urban settlements in our country but its development has been equally interesting and complicated. The onset of the industrial revolution meant a major breaking point in particular because the following gründer period has marked it most notably.The characteristic of the city is, beside a large urban fragmentation and complex disorder influenced by the local field configuration, especially the phenomenon of garden cities. Liberec with Prague, Usti nad Labem, Brno and Opava accounted for one of the centers of the second stream of culture, represented by German-speaking architects settled on our territory, which formed a natural counterpart to the architecture of the Czech majority.
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