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Design of powder preheating for cold spray technology
Kalina, Jan ; Čupera, Jan (referee) ; Řehořek, Lukáš (advisor)
Cold spray is a technology that ranks among the thermal coatings. Its main idea is to prevent both the sprayed and the underlying material from reaching the melting temperature in order to reduce the level of surface oxidation. Cold spray is a relatively young technology that is still being researched. The effect of preheating the sprayed material on the material characteristics of the cold spray is one of the research questions. As part of this work, a device for preheating the powder to temperatures of up to 650 °C is designed in such a way as to minimize interference with the current construction of the Cold Spray workstation at the ÚMVI FSI BUT in Brno. The design is based on significant simplifications of the thermal model of the preheating device and heat losses. In the theoretical part, the reader was introduced to the history of Cold Spray, the effects of various technological parameters of Cold Spray on the resulting spray. Furthermore, the requirements for the preheater device were discussed, several variants of the device design were proposed, and the equations used for the device design were written. In the practical part, the required data for the design of the equipment is obtained for the required materials of the sprayed material, different temperatures, and other input parameters of the Cold Spray injection with the help of equations from the theoretical part. Based on them, the final design of the preheater device is compiled.
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Investment Portfolio Addition Proposal of the Sector Focused Exchange Traded Fund
Kalina, Jan ; Bílek, Michael (referee) ; Rejnuš, Oldřich (advisor)
The subject of the bachelor thesis is the creation of proposal to supplement investment portfolio of sector focused Exchange Traded Fund with direct replication with stocks traded on NYSE according to the requirements of the fund management. The content of the theoretical part of the bachelor thesis is description of its theoretical and legal background. The analytical part consists of the primary selection of companies, their analysis, comparison and verification. In conclusion the proposal to supplement investment portfolio of ETF is presented to the fund management.
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Design of powder preheating for cold spray technology
Kalina, Jan ; Čupera, Jan (referee) ; Řehořek, Lukáš (advisor)
Cold spray is a technology that ranks among the thermal coatings. Its main idea is to prevent both the sprayed and the underlying material from reaching the melting temperature in order to reduce the level of surface oxidation. Cold spray is a relatively young technology that is still being researched. The effect of preheating the sprayed material on the material characteristics of the cold spray is one of the research questions. As part of this work, a device for preheating the powder to temperatures of up to 650 °C is designed in such a way as to minimize interference with the current construction of the Cold Spray workstation at the ÚMVI FSI BUT in Brno. The design is based on significant simplifications of the thermal model of the preheating device and heat losses. In the theoretical part, the reader was introduced to the history of Cold Spray, the effects of various technological parameters of Cold Spray on the resulting spray. Furthermore, the requirements for the preheater device were discussed, several variants of the device design were proposed, and the equations used for the device design were written. In the practical part, the required data for the design of the equipment is obtained for the required materials of the sprayed material, different temperatures, and other input parameters of the Cold Spray injection with the help of equations from the theoretical part. Based on them, the final design of the preheater device is compiled.
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Possibilities of utilization of PUR-foams for masonry structures with integrated thermal insulation construction
Kalina, Jan ; Horký,, Ondřej (referee) ; Zach, Jiří (advisor)
The bachelor thesis deals with the issue of PUR foams for the construction of masonry structures with integrated thermal insulation layer. The main emphasis of the work focuses on the use of the one-component PUR foam for filling high-volume bulk ceramic masonry blocks. In the practical part of the bachelor thesis there is further described manufacture of test specimens of selected PUR foams and tests that were performed on samples. The aim of the bachelor thesis was selecting of PUR foam that is the best suited as an integrated thermal insulation in masonry structures. In conclusion there is the evaluation of tests, the comparison of test results and the recommendation of appropriate PUR foam.
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Centralization of Java Security Policy Management
Kalina, Jan ; Rogalewicz, Adam (referee) ; Letko, Zdeněk (advisor)
WildFly is a platform for distributed environment which meets specification of Java Enterprise Edition. This thesis deals with possibilities of centralized management of security policies in this environment. Security policy is a set of permissions to which the Java virtual machine (JVM) limits possibilities of running applications. Just possibilities of security policy using was in WildFly so far heavily restricted. The result of the thesis are extensions of WildFly which add possibility of central deployment of security policies to individual servers, without need for restart that server, into program interface of WildFly and into WildFly management console. Part of result is also patch of core of WildFly, which solve problem of exchange security policy at runtime of JVM.
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Development of advanced masonry components for low energy and passive buildings
Kalina, Jan ; Stančík,, Hynek (referee) ; Zach, Jiří (advisor)
Diploma thesis deals with issue of another possible application of PUR foam in the building, especially during the construction of the masonry structures with the integrated thermal isolator in the low-energy and the passive buildings. The practical part shows the production of the test sample of selected PUR foams and the trials that were performed on the samples. The aim of the thesis was choosing of the PUR foam with the best attributes which would be suitable as an integrated thermal isolator into masonry structures. In the conclusion there was chosen the best foam from which the masonry fragments were made. The static tests were performed on these fragments.
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Development of i-CT Framework and Application for Communication of YES/NO Type
Kalina, Jan ; Kočí, Radek (referee) ; Fiala, Jiří (advisor)
This master thesis deals with issues of development of applications for augmentative and alternative communication (AAC) in environment of special education for mentally challenged pupils with communication disorders. Thesis presents issues of development contemporary applications and follows on design principles of Computer therapy project, which compliance during the design and implementation should prevent the current issues. The aim of the thesis is creation of application for AAC of YES/NO type and i-CT framework - framework simplifying creation of similar apps for described environment. Both apps works on iOS and Android systems and were tested in an environment of people with mental disabilities.
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Statistical Method Selection Matters: Vanilla Methods in Regression May Yield Misleading Results
Kalina, Jan
The primary aim of this work is to illustrate the importance of the choice of the appropriate methods for the statistical analysis of economic data. Typically, there exist several alternative versions of common statistical methods for every statistical modeling task\nand the most habitually used (“vanilla”) versions may yield rather misleading results in nonstandard situations. Linear regression is considered here as the most fundamental econometric model. First, the analysis of a world tourism dataset is presented, where the number of international arrivals is modeled for 140 countries of the world as a response of 14 pillars (indicators) of the Travel and Tourism Competitiveness Index. Heteroscedasticity is clearly recognized in the dataset. However, the Aitken estimator, which would be the standard remedy in such a situation, is revealed here to be very inappropriate. Regression quantiles represent a much more suitable solution here. The second illustration with artificial data reveals standard regression quantiles to be unsuitable for data contaminated by outlying values. Their recently proposed robust version turns out to be much more appropriate. Both\nillustrations reveal that choosing suitable methods represent an important (and often difficult) part of the analysis of economic data.
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Statistical Method Selection Matters: Vanilla Methods in Regression May Yield Misleading Results
Kalina, Jan
The primary aim of this work is to illustrate the importance of the choice of the appropriate methods for the statistical analysis of economic data. Typically, there exist several alternative versions of common statistical methods for every statistical modeling task and the most habitually used (“vanilla”) versions may yield rather misleading results in nonstandard situations. Linear regression is considered here as the most fundamental econometric model. First, the analysis of a world tourism dataset is presented, where the number of international arrivals is modeled for 140 countries of the world as a response of 14 pillars (indicators) of the Travel and Tourism Competitiveness Index. Heteroscedasticity is clearly recognized in the dataset. However, the Aitken estimator, which would be the standard remedy in such a situation, is revealed here to be very inappropriate, regression quantiles represent a much more suitable solution here. The second illustration with artificial data reveals standard regression quantiles to be unsuitable for data contaminated by outlying values, their recently proposed robust version turns out to be much more appropriate. Both illustrations reveal that choosing suitable methods represent an important (and often difficult) part of the analysis of economic data.
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