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Stability of crystalline solids from first principles
Řehák, Petr ; Šob, Mojmír (referee) ; Černý, Miroslav (advisor)
This work deals with study of stability of solid crystals under isotropic loading. Ab initio methods were used for this purpose. Crystals of four fcc metals (Al, Cu, Ir, Au) and diamond were subjected to simulated isotropic tensile deformation and maximum value of isotropic stress was evaluated for them. Consequently, phonon spectra were calculated for several strain values in order to assess crystal stability. Phonon instabilities in dispersion curves of diamond, Al, Ir and Au appeared at strains lower than those corresponding to their decohesion. This appearance of instability determinates the value of ideal strength. However, significant reduction (by about 20%) was found only in the cases of Au and Ir.
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Solar cell non-destructive analysis
Černý, Michal ; Škarvada, Pavel (referee) ; Macků, Robert (advisor)
This thesis briefly analyse contemporary situation of photovoltaic systems and their actual developemenet. It shows a typical properties of most produced up-to-date types. Decision point of this thesis consist in nondestructive analyse of monocristalic unijunction solar cells. It describes two main diagnostic aproaches. First – through the use of measuring of VA characteristics, second – through the use of measuring noise characteristics. With selected samples are performed experimental measurements and estabilished basic parameters. In case of drone analysis considerably attention is devoted to experimental equipment for automatized measuring of spectral power density. This experimental equipment is consequently used for measuring some samples where we can observe microplazmatic noise.
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Working out of methodology for creation of building information mode
Sládková, Veronika ; Černý, Martin (referee) ; Hanzl, Vlastimil (advisor)
The subject of thesis was creation of methodic for building information modeling methods specified. The buildings were surveyed at first or projects drawing were provided. Processing of survey data and building information modeling was done in software Revit 2014 with program extensions. Subsequently chosen methods of creation were described and they were compared with each other. The result can use for selection the most appropriate method on the basis function and targeted funds.
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Working out of methodology for creation of building information model
Nováková, Věra ; Černý, Martin (referee) ; Hanzl, Vlastimil (advisor)
This thesis is focused on creation of building information model (BIM) for existing buildings. The main objective of this work is to develop the methodology (workflow) for the creation of BIM model using selected geodetic methods, specifically for the modeling based on the existing documentation of the building, the modeling from the handheld distance meter and the modeling from point cloud acquired by the indoor mapping system. The aim of these workflows is to explore the suitability of these methods, to check the limits of each method and to point out the potential issues. Revit (version 2013 and 2014) was used as an authoring environment for creation of the models. Workflow for modeling based on the documentation of the building shows how to insert drawings into Revit and how to create a model based on these drawings. The workflow was developed based on experience with creation of model of an office building. The workflow for handheld laser distance meter describes how to work with rangefinder equipped with Bluetooth, which allows user to create a model onsite. The third part of this thesis deals with creation of BIM from pointcloud acquired by indoor mobile mapping system. The workflow describes data collection and point clouds processing directly in Revit using the ScanToBIM extension. The results of this work are methodical instructions for the methods described above and the comparison of these methods. Workflows contain recommended procedures and highlight common issues and mistakes. This should enable the readers of this thesis to choose the right method and avoid common mistakes.
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Business Plan for Developement of a Small Company
Černý, Michal ; Kyselák,, Pravoslav (referee) ; Bayerová, Vladimíra (advisor)
The aim of my Master thesis “Business Plan for the Development of a Small Company“ is to provide a solution to how to develop a micro-company into a successful small company, which will have a real potential to find its stable position on the current market. My Master thesis consists of a theoretical part, problem analysis and my own proposal of the solution. The theoretical part deals with the key findings and solutions, which are further applied in the next part of my work. Analysis is focused on present and future company environment. Concrete recommendations have been formulated on the basis of analysis conclusions. The final proposal is formulated into a complex procedure, which provides the way to reach company development.
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Optimization and parameter measurement of PON network FTTX
Černý, Michal ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Práce rozebírá současný vývoj na poli pasivních optických sítí a jednotlivé generace přenosových standardů. Podrobněji se zabývá parametry ODN, metodami jejich měření a volbou potřebných měření v praxi. Hlavní část práce je zaměřena na měření pasivního WDM prvku, kde je provedena analýza vstupů a výstupů, měření vložného útlumu a přelechů podle ORL na provozních vlnových délkách.
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VoIP Security
Černý, Michal ; Číka, Petr (referee) ; Kovář, Petr (advisor)
Internet telephony becomes still more popular option to common telephone service. Reason may be it's price as well as availability. With growing popularity grows the risk of unauthorized use of transferred data too. There are several ways to secure VoIP communication. This bachelor's thesis talk about one of many, which is use of Secure RTP. There will be made it's implementation in the software telephone exchange Asterisk and tested functionality by trial talks and analysis of network traffic as well.
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Intrusion Detection and Prevention Systems
Černý, Michal ; Vymazal, Michal (referee) ; Pust, Radim (advisor)
The detection and intrusion prevention systems could be realized as independent hardware or set in the software form on to the host. The primary purpose of these protective elements is the undesirable activity detection such as integrity intrusion of the files, invalid attempts while connecting to the remote service or acquisition of the local network data. The systems react to the event on the basis of the action that is defined by internal rules. We can include the caution sending or communication blocking among possible counteractions. The base principals of the detection and intrusion prevention systems are described in the dissertation. Various types of captured data analyses and processes of the inhere rules creation and further more caution formats are mentioned in the dissertation. There are also considered the alternatives of their location including advantages of selected situations. There is described the installation and setting up of particular elements of the realized network and security systems. In order to the verification of functionality and factor of the protection providing there was realized several selected types of attacks.
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Vinyl prepolymers - methods of preparation and application
Černý, Miroslav ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation.
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