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Searching optimal strategies for the number field sieve
Perůtka, Lukáš ; Růžička, Pavel (referee) ; Drápal, Aleš (advisor)
In this work we study the number field sieve algorithm. Our main focus is on its theoretical background. We present all important theorems which are needed for a full understanding of the algorithm. We also describe the most widely used implementation of the parts of the algorithm and we discuss in which situation they should be used. At the end we show results from measurements of sieving phase on the implementation which was written for our Department of Algebra.
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Adaptive parameterization for Aerodynamic Shape Optimization in Aeronautical Applications
Hradil, Jiří ; Rudolf, Pavel (referee) ; Růžička, Pavel (referee) ; Píštěk, Antonín (advisor)
Cílem mé disertační práce je analyzovat a vyvinout parametrizační metodu pro 2D a 3D tvarové optimalizace v kontextu průmyslového aerodynamického návrhu letounu založeném na CFD simulacích. Aerodynamická tvarová optimalizace je efektivní nástroj, který si klade za cíl snížení nákladů na návrh letounů. Nástroj založený na automatickém hledání optimálního tvaru. Klíčovou částí úspěšného optimalizačního procesu je použití vhodné parametrizační metody, metody schopné garantovat možnost dosažení optimálního tvaru. Parametrizační metody obecně používané v oblasti aerodynamické tvarové optimalizace momentálně nejsou připravený na komplikované průmyslové aplikace vyskytující se u moderních dopravních letounů, které mají šípová zalomená křídla s winglety a motorovými gondolami, přechodové prvky spojující např. trup s křídlem atd.. Existuje tedy potřeba nalezení obecné parametrizační metody, která bude aplikovatelná na širokou škálu různých geometrických tvarů. Free-Form Deformation (FFD[1]) parametrizace může, vzhledem ke svým schopnostem při zacházení s geometrií, být odpovědí na tuto potřebu. Adaptivní parametrizace by se měla být schopna automaticky přizpůsobit danému tvaru tak, aby byly její kontrolní body vhodně rozmístěny. Což umožní dostatečnou kontrolu deformací objektu, která zaručí možnost vytvoření optimálního tvaru objektu a splnění geometrických omezení. Primární aplikací takové parametrizační metody je deformace tvaru objektu. Dalším navrhovaným cílem je modifikace FFD parametrizační metody pro současné deformace tvaru objektu a CFD výpočetní sítě, umožnující velké deformace objektu při zachování kvality výpočetní sítě.
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Study of Process Control in Selected Products
Růžička, Pavel ; Bednář, Josef (referee) ; Jurová, Marie (advisor)
The thesis focuses on the process of production of castings in the company ŽĎAS, a.s. and its methods for implementing customer's requirements. The goal was to create a Work Flow diagram of technical preparation of production based on the company's internal directives. The next step was to compare it with the actual situation represented by a case job and to make a conclusion. The customer's requirements for the case production order included increased level of control and purchasing weld-on parts. The incorporation process for these requirements was not described by the original Work Flow and was the subject of its new revision. For its better practical application the Study contains business and organizational structures of ŽĎAS, a.s.
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The Evaluation of an Investment Plan
Široká, Pavlína ; Růžička, Petr (referee) ; Pernica, Martin (advisor)
The intention of this diploma work is based on an assessment of the present state of the company Industrial Engineering Ltd. to economically evaluate the effectiveness of planned investment. The last state of the company is evaluated by using financial analysis. For evaluating of the effectiveness are used static and dynamic methods. The conclusion of the diploma work evaluates investments and recommendations based on these facts and after assessing the risks of investments.
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Current trends of reduction NOx in the context with the prepared legislation
Růžička, Pavel ; Brummer, Vladimír (referee) ; Jecha, David (advisor)
This bachelor's thesis deals with processes of generating and methods of abating nitrogen oxides contained in flue gases in the context of Czech and European legistation. It compares the new enviromental act with its predecessor and scetches the pull of the new emission limits on stationary sources of air pollution. With particular focus on NO and NO2, the summary of NOx compounds hands a brief review of every individual one, which amongst other matters includes their impact on public and enviromental health. In the next part the paper aims at primary and secondary measures of NOx reduction together with factors influencing their utilization. Last chapter inquires into methods of selective catalytic and non-catalytic reduction and means of thier engagement in industry.
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The use of carpentry joints for the repair of historical structures
Kloiber, Michal ; Kunecký, Jiří ; Hasníková, Hana ; Sebera, V. ; Tippner, J. ; Fajman, P. ; Růžička, P. ; Stejskal, D.
The conservation process describes the way of using prosthesis lap scarf carpentry joints for reconstruction of historical timber structures. This new scarf joint makes use of the strutting effect of inclined contact faces where the forces are transmitted through wooden coupling elements - wooden dowels or keys. The process consists of several chapters describing the diagnostics of original wood and the repaired structure, the design of the joint and execution of the joint. It also includes examples of succesful reconstruction made with according to this conservation process.
Fulltext: content.csg -  PDF
Plný tet: 0459383_2015_Kloiber_et_al_Vyuziti_celodrevenych_tesarskych_spoju_pri_opravach_historickych_konstrukci_PP_NAKI-004_AVV - PDF
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Measurement of laser beam parameters
RŮŽIČKA, Prokop
The bachelor thesis deals with the proposal of methodology for measuring basic laser beam parameters in optical laboratory of the Institute of Physics and Biophysics at the Faculty of Science University of South Bohemia.
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Input evaluation of sustainable consumption and production upgrade options
Kodejšová, Tereza ; Plášková, Alena (advisor) ; Růžička, Pavel (referee)
The aim of the thesis is the application of input evaluation methods related to sustainable consumption and production in a selected company. within the thesis This methodology is applied to a specific enterprise and identifies potential for improvement in all its parts, i.e. in the whole system of production and consumption influenced by the enterprise including the incorporation of all economic, environmental and social aspects. The result of this evaluation is a set of proposed measures, the anticipated implementation costs of which are calculated in relation to their realization, payback period and also the effects of these benefits. These measures are recommended to the enterprise for implementation in order for it to achieve savings, increased competitiveness, improved economic performance, strengthen social prestige, and reduce the negative environmental impact and other effects.
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Experimental examination of EFL and MATX eukaryotic horizontal gene transfers: co-existence of mutually exclusive transcripts predates functional rescue
RŮŽIČKA, Petr
Many eukaryotic genes do not follow simple vertical inheritance. Elongation factor 1? (EF-1?) and methionine adenosyl transferase (MAT) are enzymes with complicated evolutionary histories and, interestingly, the two cases have several features in common. These essential enzymes occur as two relatively divergent paralogs (EF-1?/EFL, MAT/MATX) that have patchy distributions in eukaryotic lineages that are nearly mutually exclusive. To explain such distributions, we must invoke either multiple eukaryote-to-eukaryote horizontal gene transfers (HGTs) followed by functional replacement, or presence of both paralogs in the common ancestor followed by longterm co-existence and differential losses in various eukaryotic lineages. To understand the evolution of these paralogs, we have performed in vivo experiments in Trypanosoma brucei addressing the consequences of long-term co-expression and functional replacement. In the first experiment of its kind, we have demonstrated that EF-1? and MAT can be simultaneously expressed with EFL and MATX, respectively, without affecting the growth of the flagellates. After the endogenous MAT or EF-1? was down-regulated by RNA interference, MATX immediately substituted for its paralog, while EFL was not able to substitute for EF-1?, leading to mortality. We conclude that MATX is naturally capable of evolving patchy paralog distribution via HGTs and/or long term co-expression and differential losses. The capability of EFL to spread by HGT is lower and so the patchy distribution of EF-1?/EFL paralogs was probably shaped mainly by deep paralogy followed by long term co-existence and differential losses.
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