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Model of insufficient heart supported by rotary pump (Mechanical study)
Pražák, Josef ; Musil, Jan ; Leitermann, D.
The insufficient heart may be supported by rotary pump connected to the left heart in parallel. Behaviour of a heart can be characterized by Frank-Starling's curve, i.e. the cardiac output is function of only the heart rate. Values of cardiac output of insufficient heart are lower than the ones of healthy heart. The task of rotary pump is to transform the cardiac output to higher values. This transformation has to respect minimum value of ejection fraction.
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A unified view on roots of imperfection
Kárný, Miroslav
Decision making (DM), broadly interpreted as an active choice among alternatives, is ubiquitous. A range of normative theories has arisen aiming at support and analysis of DM. Classical Savage's axiomatisation led to Bayesian DM, which suits DM with a non-negligible uncertainty. Observed discrepancies between recommendations of the normative theory and DM practice represent the major challenge of the related research. The talk discusses these discrepancies, and: a) respects the presence of imperfect decision maker; b) considers neglecting of importance of closed-loop behaviour as their major cause; c) provides tasks where a) and b) do matter and where a unified view on imperfection roots can help.
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Numerical Analysis of the Thickness Influence on the Stress Field at Crack Tip for Different Poisson´s Ratios
Seitl, Stanislav ; Hanzlovský, Radovan ; Fernandez, C.
The influence of in- and out- of plane constraints on the behaviour of cracks under mode- I loading condition is studied. The independence of the stress intensity tensor structure, with respect to the specimen thickness B shows that under loss of constraint conditions higher order tensor members of the Williams expansion must be considered to characterize the singular stress field, and to explain the increasing apparent fracture toughness resulting experimentally for decreasing specimen thickness. A numerical study of the effect of Poisson’s ratio on stationary mode I crack tip fields is presented in the contribution. Finite element calculations for two-dimensional (v =0) and three-dimensional bodies are performed and compared. Further, the stress intensity tensor K, and the elastic txx and tzz components of the tij constraint tensor in the middle of a three-dimensional crack front are determined using direct methods for the same level of loading.
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Resonance behaviour of spherical pendulum – influence of damping
Fischer, Cyril ; Náprstek, Jiří ; Pospíšil, Stanislav
Experimental and numerical model of a uni-directionally driven pendulum-based tuned mass damper is presented in the paper. Stability of the motion in a vertical plane is analysed in the theoretically predicted resonance region. For the experimental part, special experimental frame is used, allowing independent change of linear viscous damping in the both perpendicular directions. Mathematical model respects the non-linear character of the pendulum and allows to introduce asymmetrical damping. Sensitivity of the resonance behaviour on the change of damping in both directions is studied and commented in the paper. The stability of the system is analysed experimentally and compared with numerical and theoretical results.
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Differentiation and Dynamics of Fertility in Kazakhstan during the Period of Rapid Economic Growth
Meldeshova, Aigerim ; Burcin, Boris (referee) ; Kučera, Tomáš (advisor)
The main purpose of presented research was to identify changes in levels and patterns of fertility during the period of rapid economic growth in Kazakhstan (1999-2008). Particular attention was devoted to differentiation of fertility according to the type of settlement (urban/rural) and ethnicity. These leading attributes were completed by birth parity which helped to examine and explain the nature of some principal differences in reproductive behaviour among women living in rural and urban areas as well as belonging to selected major ethnic groups of Kazakhstan. Presented results clearly demonstrate principal increase of the overall intensity of fertility, partially due to mass realization of the births postponed during the 1990s. Their realization not only contributed to reproductive process intensification but also principally influenced different fertility patterns. The initial age structure of fertility faced both-sided ageing, differences among ethnoses and both types of settlement in many respects deepened. Situation observed in the year 2008 or in some cases in the year 2006 was labeled as transitional since many structural changes have not finished yet and some of them have only just started. It is suggested that particular identified trends could also represent a part of global changes in...
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Superconvergence for discontinuous Galerkin time discretizations
Roskovec, Filip ; Vlasák, Miloslav (advisor) ; Knobloch, Petr (referee)
The topic of this thesis is the application of the discontinuous Galerkin finite element method (DGFEM) on space-time discretizations of simple nonstationary problems. Unlike the standard finite element method, discontinuous Galerkin method does not require any continuity between neighbouring elements. We apply the DGFEM separately in space and in time. At first, we implement discretization with respect to space variables, whereby we acquire the space semidiscretization. Subsequently we apply Time discontinuous Galerkin method to the problem. We seek the aproximate solution in the space of discontinuous piecewise polynomial functions of degree p in space and degree q in time. This is followed by the error estimates of this scheme. In the end we examine the supercovergence behaviour of the scheme in nodes of the time discretization. The theoretical results are verified by numerical experiments.
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Dvoukanálový, komplexní, bioimpedanční signál pro vyhodnocení hemodynamiky
Halámek, Josef ; Vondra, Vlastimil ; Jurák, Pavel ; Verner, Petr
The complex bioimpedance signals measured in the aortal and pulmonary artery directions simultaneously are discussed with respect to the information about the heart activity. All four signals carry some information about the blood flow, this information is partly equivalent (only SNR improvement and some artefact minimizations may be achieved by processing all signals) and partly non-equivalent (different behaviour according to excitation of the cardiovascular system). The more detailed analysis of time evolution of signal parameters according to the used excitation may contribute to new information about the hemodynamic system.
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Influence of bi-materials interface on crack interaction
Seitl, Stanislav
Existence of the interface between regions with different elastic properties has a pronounced influence on the behaviour of cracks. The aim of the present contribution are a modelling and analysis of two perpendiculars cracks growing in a vicinity of the interface between two different elastic materials. The dependence of stress intensity factor for mod I (KI) on the distance of a crack with respect to the interface is studied. The results contribute to better understanding of crack's behaviour in relation to microstructure of material.
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Europe "A la FranÇaise" - France and its Attitude Towards Institutional Reforms in the European Union with Respect to Franco-German Co-operation
Kristková, Lenka ; Perottino, Michel (advisor) ; Tomalová, Eliška (referee)
Diploma thesis deals with the position of France towards reforms of European institutions, which were discussed during the Intergovernmental conference in 2000 and in the European Convention followed by Intergovernmental conference in years 2002-2004. French behaviour during the Intergovernmental conference 2000 was designated as "arrogant" without the ability to compromise. During this conference the Franco- German co-operation failed, which was reflected in the final outcome of negotiation. Two years later in the European Convention, France changed its behaviour and demonstrated the willingness to compromise. France also returned to intensive Franco-German co-operation and this co-operation distinctively influenced the final institutional reforms in the European Constitution. In the period of time since Nice to the Convention, France reassessed its perception of the European integration with respect to geopolitical changes in Europe and forthcoming enlargement of the Union and found the way how to preserve the influence also in this "new" and bigger Europe. Powered by TCPDF (www.tcpdf.org)
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Political ideas of Bohumil Laušman in the years 1941-1944
Horák, Pavel ; Kuklík jun., Jan (referee) ; Čechurová, Jana (advisor)
Socialdemocratic parties played a very important role in the tactics of communists in the countries of Sovieťs interest after the World War II. It was based on cooperation with social democrats and then on "unification" of both of the "labour" parties in conditions of so called popular, respectively national fronts. The very beginning of these cooperations could have started in the middle ofthe year 1941 after the US SR had entered the War. The initiation to cooperation of the left-wing partie s was coming out of the "left-wing" fraction of social democrats in London's exile at that time. Its representative was Boumil Laušman, whose obvious left-wing tendency and non-constructive behaviour are possible to be seen after the failure of his political formation of Czechoslovakia's resistance movement in Paris and London. So he left in the middle of the year 1942 to the USSR to get to know c10ser the political ideas of the representatives of the Czechoslovakia' s resistance living there, possibly to get their politi cal support. In the negotiations he offered communists mainly the possibility of advancement together with "lef-wing" group of the social democrats in London's exile institutions, at first the participation in the government. This cooperation was to be done with the perspective of uni:fYing the...
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