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Antenna system for wireless microphones
Bartoš, Adam ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
Master's thesis deals with the design of an antenna system for wireless sound transmission used mainly in professional sound reinforcement. The introductory part deals generally with wireless microphones, frequency bands used and proven antenna types. Next, this work deals with signal distribution that is realized using the antenna splitter. The antenna parts is focused on easy production and real usage, therefore were selected antennas with appropriate properties suitable for small series production. This thesis includes simulation of each device, their real construction design and measurements of built prototypes and final products. All three produced devices – the rack splitter, /4 antenna and Helix antenna are fully working, achieve good parameters and are ready for further manufacturing and easy modifications in case of frequency band change requirement. The conclusion includes an overall assessment of the results achieved.
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Machining technology of external threads
Kabrda, Martin ; Osička, Karel (referee) ; Prokop, Jaroslav (advisor)
This bachelor's thesis focused on "Thread cutting technology" complexly deals with the individual types of threads, their designation and their use in practice, including norms specifying their standardization. There are also described methods of machining of external threads, which include cutting, turning, milling or grinding. The last chapter describes methods of economic comparison of individual machining methods.
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Phylogeny of the genus Helix (Mollusca: Gastropoda: Helicidae)
Korábek, Ondřej ; Juřičková, Lucie (advisor) ; Horáček, Ivan (referee)
The land snail genus Helix comprises large gastropods distributed in from France to Iran and in North Africa. Some of them have close linkage to humans - are synanthropic or are collected and consumed. The genus is most diverse in eastern Mediterranean. Taxonomy of the genus is now being revised from morphological point of view, and a molecular study is needed as a counterpart to that study. Here I present first phylogenetic data for the genus Helix, including almost all currently recognised species. I have used samples from various sources including dried bodies and tissue remnants. I have sequenced two commonly used mitochondrial markers (16S, COI). Position of the genus within Helicidae cannot be inferred from the dataset. The genus should be delimited in a strict sense, excluding genera Maltzanella, Cantareus, Cryptomphalus and Lindholmia. Division into subgenera, as proposed by various authors until now, is not supported with the exception of a split between subgenera Pelasga and the nominotypical Helix. Relationships between species and their groups are poorly resolved. Regarding species limits, the data are largely in agreement with new opinions based on morphology. There might be surprisingly high variability in shell characters within a species, as few morphologically characteristic taxa seem to be...
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Machining technology of external threads
Kabrda, Martin ; Osička, Karel (referee) ; Prokop, Jaroslav (advisor)
This bachelor's thesis focused on "Thread cutting technology" complexly deals with the individual types of threads, their designation and their use in practice, including norms specifying their standardization. There are also described methods of machining of external threads, which include cutting, turning, milling or grinding. The last chapter describes methods of economic comparison of individual machining methods.
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Worm conveyor
Sencovici, Patrik ; Jonák, Martin (referee) ; Malášek, Jiří (advisor)
This bachelor thesis deals with calculation and construction of worm conveyor for the transport of hydrated lime. Thesis is created from text part and drawing documentation. Text part be occupied with calculation basic parameters, design drive, loading, imposition of bearings and strength calculation of worm conveyor. Drawing documentation contains drawing assembly of worm conveyor and manufacturing drawings of spiral worm.
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Summary of the taxonomy of the genus Helix.
Korábek, Ondřej ; Juřičková, Lucie (advisor) ; Král, David (referee)
Despite the genus Helix Linnaeus, 1758 (Gastropoda, Pulmonata) comprises large and common land snail species, it is rather neglected by taxonomists. A vast number of species and subspecies level taxa were described along 19th century, most of them currently not considered as valid. Nevertheless, there remain doubts about species delimitation. It is obvious, that there is great morphological variability in some species, but little is known about its taxonomic value. Today, about forty valid species are recognized. The diversity center of this genus is situated in northeastern Mediterranean. The distribution data of particular taxa are fragmentary and ecology of some species is largely unknown. No collections are still available from extensive areas, thus completion of field collecting can lead to changes in status of some taxa or perhaps even to description of new species. This work is based on the review of available literature and partly also on the study of collection materials. It provides a list of available names in the genus Helix in its present sense. The problems of traits used for species identification as well as weak points of current knowledge of diversity of the genus Helix are briefly discussed.
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Geometry in architecture
BÁRTOVÁ, Michaela
The reader will understand the relationship between geometry and everyday life. Selected curves and bodyes are mathematically described. It is illustrated with photos of architectural elements. 3D models are made in GeoGebra and SketchUp. Blending theory and practice to help understand the geometry. It can be used for teaching math and geometry. This thesis discusses about the conic, selected technical curves and quardics.
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Assessment of Company Financial Situation Using Time Series
Dvořák, Václav ; Štěpánková, Vladěna (referee) ; Novotná, Veronika (advisor)
This bachelor’s thesis focuses on the use of statistical methods in practice, especially interested in the financial analysis of HELIX Liberec s.r.o. expressed by selected economic indicators in the time series from 2000 to 2010. The work has both theoretical and practical parts. The theoretical part is important to clarify the terms of the statistical and financial analysis in the practical part will apply the theoretical basis for undertaking an assessment of the situation and outline possible recommendations for improvement.
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Multimodal Databases
Kuncl, Jiří ; Burget, Radek (referee) ; Chmelař, Petr (advisor)
This masters thesis is dedicated to theme of multimodal databases, especially multimedia databases. The first part contains overview of today's most used data models. Next part summarizes information about content-based search in multimedia content and indexing this type of data. Final part is dedicated to implementation system for storing and managing of multimedia content based on Helix streaming system a PostgreSQL database system.
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Electrically short multiband antenna for radioamateur use
Müller, Marek ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
The purpose of this work is identification with theory of EH antennas, do the simulation of one choice of model of EH antenna from literature and this model optimise on required frequency 14 MHz through the use of computer software CST Microwave Studio. The practical part of work is to produce choice model of EH antenna, to mete his properties and to verify use in real traffic. The EH antenna is an electromagnetic electrically short antenna, which can work as a transmitting or receiving antenna. The main characteristic of EH antenna is distributed radiating electromagnetic field, whose electric component E and magnetic component H are mutually crossed and orthogonal. The advantage of EH antennas is, that they have much smaller size on frequencies in order of magnitude MHz in comparison with conventional antennas (e.g. half-wave dipole). Their disavantages are their more complicated construction and tuning of the antenna, which must be made again, when the position of antenna is changed. Therefore the EH antenna is not so suitable for mobile application.
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