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Degradace motorového oleje v novém vznětovém motoru osobního automobilu
Stejskal, Jan
The diploma thesis deals with the issue of motor oil degradation in a new diesel car engine. Oil, which changes its physical and chemical properties during engine operation, also provides information on the technical condition of the equipment. For this reason, it is appropriate to monitor the course of oil use and respond adequately to the results obtained. As part of the experiment, engine oil samples were taken at regular intervals from two diesel passenger cars, both from a new and a similar car with a higher mileage for subsequent comparison. The sampling methodology, the tested vehicles as well as the instruments that were used for the evaluation are presented. In addition to viscosity and density trends, the oxidation and nitration status of the oil, the content of water, carbon black, additives, glycol and partially abrasive particles contained in the oil were also monitored. The obtained results were processed into brief graphs and tables and at the end of the work they are summarized, discussed and compared.
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Analysing the ESG stocks: Are they less volatile?
Stejskal, Jakub ; Čech, František (advisor) ; Hanus, Luboš (referee)
In this thesis, we investigate the relationship between ESG (Environmental, Social, and Governance) scores and stock volatility using panel data analysis. Focusing on data from 2 095 companies from three major stock exchanges - NAS- DAQ, NASDAQ Nordic, and Johannesburg stock exchange in the time window of 2016-2023, we employ fixed effects and random effects models with robust standard errors. We examine the overall impact of ESG scores on volatility, the influence of individual pillar scores, industry and stock exchange-specific effects, and time-specific effects. The thesis enhances existing literature by exploring three previously unexamined trends: non-linear dynamics between low-ESG score and volatility, the evolution of the trend over time by using an expanding time-window approach, and geographically and market-specific ef- fects by utilizing data from different stock exchanges. The results from our analysis indicate that while the influence of ESG scores on overall stock volatil- ity across the dataset is insignificant, significant correlations were observed in certain industry-specific models. The Technology, Industrials, and Healthcare sectors displayed a significant negative correlation between Governance scores and volatility. Moreover, for stocks listed on NASDAQ Nordic, there was a...
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Foreigners in the Czech Republic: history, trends and patterns
Stejskal, Jan ; Rychtaříková, Jitka (advisor) ; Fialová, Ludmila (referee)
Foreigners in the Czech Republic: history, trends and patterns Abstract This bachelor thesis focuses on foreigners legally residing in the Czech Republic from the demographic perspective. It is based primarily on data on foreigners that are available from public sources. It presents fundamental legal regulations that affect the residence of foreigners in Czechia, it also discusses the statistical registration of foreigners and the main sources of data about them. Attention is paid to the history of international migration in Czechia, to the development of the number of foreigners in Czechia, acquisition of Czech citizenship by foreigners and international protection in the Czech Republic. Space is also devoted to the demographic events and processes of foreigners, to their demographic patterns and the spatial distribution of foreigners in the Czech Republic. This thesis offers international comparisons of the number of foreigners with the member countries of the European Union. It also focuses on the Ukrainian refugee crisis that started in 2022. A new contribution of this thesis is analysis of mortality of foreigners and the structure of live births of foreigners in 2021 and 2022 including a comparison with the population of Czech citizens. It can serve as a basis for more more in-depth analysis in the...
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Analysis of the Velocity and Pressure Fields of the Liquid Using Curvilinear Coordinates
Stejskal, Jiří ; Kozubková, Milada (referee) ; Kučera,, Radek (referee) ; Veselý, Jindřich (referee) ; Pochylý, František (advisor)
This work introduces a new method of hydraulic design of a centrifugal pump impeller. This method is based on a geometrical approach employing curvilinear coordinates that are used to formulate both the axisymmetrical flow model in a meridional shape and the final model of flow in a blade cascade taking into account the full 3D shape of the impeller blade. The solution to this model then directly provides the guidelines for shaping the impeller blade in order to suppress the secondary flows, thus increasing the impeller efficiency, which is demonstrated on a real impeller design case. The partial differential equations describing the flow in the blade cascade are numerically solved piecewise on each particular stream surface, which leads to a significant reduction of computational time.
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Computation of compression force on surface
Stejskal, Jiří ; Habán, Vladimír (referee) ; Čermák, Libor (advisor)
In technical computing we often need to find the resulting load on surface caused by the compression force. The aim of this thesis is to suggest one of the possible approaches to do so if the surface is given explicitly or by the coordinates of some of it's points. In the first section, the mathematical definition of the surface with some of it's important properties is mentioned. There is a basic theory of Bézier surfaces, which form the main part of this thesis in the second part. Further on, some results from the theory of surface integrals are mentioned. The last section describes the whole algorithm of computing the resulting load together with the MATLAB program which is added to this thesis. Three examples are given at the end.
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Design systems used in the field of electrical apparatuses
Stejskal, Jiří ; Krejčí, Jan (referee) ; Valenta, Jiří (advisor)
Bachelor´s thesis is engaged on the base of submitter´s requests company OEZ, s.r.o. and is divided into two parts. The first part of work deals with the most often used 2D CAD systems that are used by designers according to their answers in the area of suggestion of electric switchboards low voltage. In the work are described main possibilities of these systems, then what kinds of data format are supported by them. In the second part of the work are described programs established on calculation of warming switchboards. It goes about programs, which supply concrete producer of switchboard case, and further programs based on method of final elements and method of final volume, which enable graphic representation of results.
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Creating an Accounting Procedure for Fixed Assets
Stejskal, Jakub ; Svirák, Pavel (referee) ; Pěta, Jan (advisor)
The bachelor thesis is focused on internal guidelines of the company BZCompany international s. r. o. The first part is focused on internal guidelines, accounting, accounting and tax depreciation and legislative aspect of the matter. The second part is introduce BZCompany international s. r. o. and examines the optimal solution for internal guidelines with regard to problematice with long-term tangible assets. In the last part of the bachelor thesis indicate optimal design for internal guidelines.
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Measuring of Velocity Profiles in Liquids by Using of UVP
Kárník, Jan ; Stejskal, Jiří (referee) ; Štigler, Jaroslav (advisor)
The following bachelor's thesis deals with one possible way of determination velocity profiles in liquids. Content of the thesis is focused mainly on the method of the UVP (Ultrasound Velocity Profile), on the ways and principles of measuring, on its pluses and cons and it´s comparison with the other conventional methods, like for the example the PIV (Particle Image Velocimetry) and LDA (Laser Doppler Anemometry). There is also the possible placement of the transducers to the measuring system discussed. Furthermore the thesis deals with trouble in the test measurement. At the beginning this work deals with familiarization with principle and function of the measuring device and with the device for the method UVP itself. Apart from the UVP measuring method the thesis also deals with short description of the competitive methods – PIV, LDA, which are used to measure the velocity profiles nowadays. Particular attention is given to the PIV method, which significance is currently growing. In conclusion, there is comparison of different methods with the UVP method made and there are the future steps to realize the successful measurement with UVP method also discussed.
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Application of Management Control System in a Business
Stejskal, Jakub ; Režňáková, Mária (referee) ; Žižlavský, Ondřej (advisor)
This diploma thesis is focused on the use of Controlling in the selected company. The thesis consists of three parts. The first part deals with the theoretical basis and knowledge and builds up the theoretical foundation for the following parts. The second analytical part deals with the selected company introduction and provides valuable information and impulses for the last design part. The third part is based on knowledge of the analytical part and contains its own suggestions for the improvements to the company's current condition.
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Hough Transform and its Variants
Stejskal, Jan ; Přinosil, Jiří (referee) ; Říha, Kamil (advisor)
This thesis focuses on basic principles of Hough transform for the detection of lines, circles and arbitrary shapes, their algorithms, computational complexity and preparation of a picture for detection. The description of implementation of individual algorithms and creation of an aplication that demonstrates their properties. Implementation has been done in programming language MS Visual C++ with the help of open source library OpenCV and user interface has been created using IDE Qt Creator 4.13.2 (Community).
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