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Spread spectrum modulator
Lejsková, Alena ; Kováč, Michal (referee) ; Maršálek, Roman (advisor)
This thesis deals with a method of spectrum-spreading of the data signals transmitted in the radio channel. There exist three different ways of spreading application, they uses pseudorandom sequences and also orthogonal sequences. In these systems we can find various kinds of modulations, one of them (Quadrature Phase Shift Keying) is shown at the end of the thesis. Spectrum spreading orthogonal multiplex OFDM is based on this method. The thesis wants to present the principle of the spectrum spreading method and the description of systems, transmitters and receivers that are using this method.
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Methods of multiple access for terrestrial radio networks
Žák, Josef ; Novotný, Vít (referee) ; Havelka, Dušan (advisor)
The content of this work is focused on the methods of multiple access for terrestrial radio network. These methods are exploited by the systems second and third generation of mobile networks. Specification the basic characteristics these methods is responsible part for inquest the correspondent specificities. Reason is that, that the wireless mobile communication it is possible split by three generation. First is NMT, with analog frequency modulation, which dont make use already, because has considerable disavantages . Analysis second generation mobile systems GSM leads to determination to many advanta- ges hereof system, who be based on methods FDMA, TDMA, CDMA. Description these methods is specialized on their spreading properties. Third generation of mobile systems UMTS is characterized wideband technology WCDMA, making use two duplex methods (FDD, TDD). Both methods provide higher efficiency of recovery frequency spectrum . All the theoretical approaches are examined in the last part of this work.it´s then possible after complete analysis these methods, make a design and a realization. In this event was used the computer programme Matlab–Simulink for simula- tion of duplex method WCDMA-FDD. Evaluation of this technology provides confrontation with second generation GSM .
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RAKE receiver for the UMTS system
Koudela, Oldřich ; Gleissner, Filip (referee) ; Prokopec, Jan (advisor)
This thesis is focused on theoretical description of procedures which take place in the UMTS system when processing a signal, its spreading with modulation technique DS SS(direct sequence spread spectrum), and subsequent processing in the RAKE receiver. Another focus is made in the basic functions of a RAKE receiver: match filtering, descrambling, despreading and integration. Aditionally, this thesis is suplemented with the results of a RAKE receiver simulation for a small number of samples in the MATLAB software and creation of aplication that simulates the receiver and its results.
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Organic solar cells prepared by methods compatible with printing technologies
Babincová, Kristina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
The theoretical part deals mainly with basic properties of organic materials, which are used in electronics, and especially in the field of photovoltaic cells. The experimental part deals with preparation of photovoltaic cells by deposition from solution, characterization of their basic electrical properties and preparation of a photovoltaic cell with its own pattern. Samples of classical and inverted structures of photovoltaic cells with P3HT and PCBM bulk heterojunction were prepared. Reference samples were prepared under standard conditions (under nitrogen). Their efficiency was around 3 %. In addition, samples were prepared by spin coating under laboratory conditions and by spreading. In both cases, their efficiency was about 1.5 %. Large-scale photovoltaic cells (active area of about 1 cm^2) were prepared in the last experiment presented. Efficiency decreased to 0.75 %. From results mentioned above is clear that very simple methods and procedures that do not impair the price/performance ratio can be used to prepare photovoltaic cells.
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Rozšíření a velikost populace bobra evropského (\kur{Castor fiber}) ve VÚ Boletice
SEIDL, Vladislav
In this bachelor thesis the information about the European beaver (Castor fiber), its historical and recent distribution in the Czech Republic including possible immigration paths is reviewed. The impact of beaver on communities of both aquatic and terrestrial organisms and its relationship with humans are described. The thesis also includes a project proposal regarding monitoring the population size and territories number of the European beaver in Boletice Military Training Area. Some management implications focused on military area are discussed.
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Organic solar cells prepared by methods compatible with printing technologies
Babincová, Kristina ; Pospíšil, Jan (referee) ; Zmeškal, Oldřich (advisor)
The theoretical part deals mainly with basic properties of organic materials, which are used in electronics, and especially in the field of photovoltaic cells. The experimental part deals with preparation of photovoltaic cells by deposition from solution, characterization of their basic electrical properties and preparation of a photovoltaic cell with its own pattern. Samples of classical and inverted structures of photovoltaic cells with P3HT and PCBM bulk heterojunction were prepared. Reference samples were prepared under standard conditions (under nitrogen). Their efficiency was around 3 %. In addition, samples were prepared by spin coating under laboratory conditions and by spreading. In both cases, their efficiency was about 1.5 %. Large-scale photovoltaic cells (active area of about 1 cm^2) were prepared in the last experiment presented. Efficiency decreased to 0.75 %. From results mentioned above is clear that very simple methods and procedures that do not impair the price/performance ratio can be used to prepare photovoltaic cells.
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Spreading of praying mantis (Mantis religiosa) in Europe
Vitáček, Jakub ; Janšta, Petr (advisor) ; Gvoždík, Václav (referee)
Climate change is one of the most important factor determining species ranges. In Europe there is now evidence for northward areal expansion in many Mediterranean insects including the praying mantis (Mantis religiosa). This species is the only representative of the order Mantodea inhabiting central Europe. The northern edge of the species distribution currently reaches latitude 53ř North. Although, the praying mantis is well known insect there is not enough evidence about its phylogeography. In this work three mitochondrial genes (COI, COII, Cyt b) were selected for phylogenetic study. Results indicate three statistically supported distinct lineages in Europe: Eastern European, Central European and Western European. Presumably these lineages are consistent with isolation during the last glacial and re-colonization from glacial refugia. Reduced haplotype diversity on the northern edge suggests currently established populations at the northern distribution border. To validate mtDNA results it was also considered four microsatellite loci. Due to different type of inheritance mtDNA and nuclear DNA it is possible to compare two independent genetic datasets. Microsatellite analysis confirmed results obtained on mitochondrial data. Three major genetic clusters were found: east, west and central. Spatial...
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Lymnaeid snails: hemocyte activities and their changes caused by Trichobilharzia infections
Jindrová, Zuzana ; Horák, Petr (advisor) ; Bilej, Martin (referee)
Molluscs as well as all other invertebrates rely on innate immune response only. Their internal defense system is capable of destroying most pathogens. However, there are some exceptions, e.g. some snails serve as intermediate hosts for some trematodes. Trematodes are able to develop inside these snails due to intervention in the snail internal defense system. The submitted thesis describes hemocyte activities of two lymnaeid snails, Lymnaea stagnalis a Radix lagotis, and the influence of Trichobilharzia regenti infection on R. lagotis hemocytes. Hemocytes of both species exposed to various chemicals produced different amounts of H2O2 and NO. The response varied between both lymnaeid species. The amount of circulating hemocytes was elevated in R. lagotis snails due to T. regenti infection. However, the infenction attenuated hemocyte activities monitored by us. Hemocyte basal NO production was decreased as well as phagocytosis of bacteria, cell adherence and pseudopodia formation. Toxicity of L. stagnalis plasma against T. regenti miracidia was also described. Mechanisms used by trematodes to interact with the snail internal defense system will help us to understand why one species is suitable for the develepment of the trematode whereas another closely related species kills it. Powered by TCPDF (www.tcpdf.org)
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The role of stream-corridors for the speading of invertebrates in the landscape
Ratajová, Michaela ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
The characteristic environment along riverbeds forms corridors, which can be used by numerous organisms for their dispersion - stream corridors. Water is a useful medium of transportation, especially for the species with low dispersion abilities, such as annelids, molluscs and several arthropods. The terrestrial animals nearby the water flows are often adapted to the survival in the water. They are able to survive short term inundation, or reproduce very quickly to renew their abundances. However, well documented cases of the species spreading along the rivers are rather rare. Most of them are molluscs species. The banks of the Vltava, Berounka or Sázava rivers are colonized by the snail Arianta arbustorum. There is evidence of the spreading of annelids along some European rivers. Such examples, together with the various adaptations to survival of inundation suggest that the stream corridors really work as a spreading device.
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Hodnocení sklízecí mlátičky s rozlišným provedením pojezdového ústrojí
BARÁK, Jan
This thesis describes chassis design of combine harvester and its types generally. This thesis is focused on Claas Lexion 750 Terra Trac Helmut combine harvester with crawler chassis. For each selected chassis and systems by global manufacturers of agricultural machinery are described main parts and their possible variants. Thesis includes practical methodical measurements, which provides details for the assessment of the losses, spreading quality, crushing quality, operating parameters, machine performance and fuel consumption. Next the effect of moisture on the losses, quality of spreading and crushing is evaluated. Furthermore, I compare effect of crawler chassis on performance and in the end is a simple analysis of investmend and operating costs and characteristics of the company. The aim of the thesis is to evaluate operation and work quality of combine harvester with crawler chassis at harvest of cereals and rapeseed in agricultural production and simple economical evaulation of the machine.
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