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Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
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The impact of polarization mode dispersion on error-rate of optical fibre link
Dorociak, Petr ; Křivánek, Vítězslav (referee) ; Kyselák, Martin (advisor)
Master’s thesis engages in the impact of polarization mode dispersion on optical communication system. Polarization mode dispersion is mathematically described by Stoke’s and Jone’s space and ensure the theoretic causes of the rise of polarization mode dispersion that are divided on the external and internal effects. On the basis of these effects grow up a differential group delay (DGD) which makes causes that individual polarization modes have between them a time delay and limitation of maximum bit rate. Then master´s thesis analyses the influence of the polarization mode dispersion on the pulse enlargement and on the modulation signal. In this work, there are described the most applicated optical modulation formats. Polarization mode dispersion has also influence on the bit error rate of optical fibre link and closing of eye diagram too. Eye diagram is used to view the transmission characteristics and diagnoses the channel errors. Eye diagram is connected with the definitions as a bit error rate (BER) and signal-to-noise ratio (SNR) that are explained in this work too. Following the gained experiences it was designed an useful graphic interface to display the effect of the polarization mode dispersion on the transmitted signal. Realization of the graphic interface is created in the program MATLAB. In Matlab-Simulink are created six models according to the kind of modulations with characteristic AWGN (Additive White Gaussian Noise) channel. Program was tested for a typical values. In all calculations it is counted only with the losses that are caused by the polarization mode dispersion. It is not calculated with the losses that are caused by a chromatic dispersion and attenuation. At the end of this work are evaluated all types of modulation formats depending on the polarization mode dispersion, optical fibre length, price and complexity of the realization. Atteined results of my master’s thesis are compared with two foreign articles.
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Modification of the filler in cement-bonded boards with alternative filamentous fillers
Dywor, Michal ; Vacula, Miroslav (referee) ; Bydžovský, Jiří (advisor)
The cement boards are commonly used as a filler fir or spruce chips-profit wood. The increasing demands for construction materials forcing technology to develop new types of composite materials using an alternative source of fillers. In this work in the context of theoretical knowledge about the specified fibers in composite systems are discussed properties of cement binder and filler for cement – bonded particleboards and alternative materials. The practical part describes the test methods designed recipes and then made boards of which were carved specimens intended for testing the properties of boards with alternative fillers.
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Design of laminate handlebars for mountain bikes
Hanák, Jiří ; Ševeček, Oldřich (referee) ; Polzer, Stanislav (advisor)
This bachelor’s thesis describes design of laminate handlebars for mountain bikes. The first part describes the mechanical properties of composite materials, with the emphasis on fiber composites. The algorithm for acquiring material characteristics of fiber composite by analytical method is presented. In the next part, it is shown how to control the direction of fibers in lam-inate in the finite element calculations and its impact to resulting stresses in the material. The aim of the last part is design geometry model of laminate handlebars for mountain bikes with following stress – strain analysis by FEM and software ANSYS. The analysis is performed for static loading.
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Filament Winding Machine
Dorňák, Michal ; Hampl,, Štěpán (referee) ; Foller, Bronislav (advisor)
The aim of this diploma thesis is the proposal of solution of three-axial winding machine for winding technology of rotary profile. Winding materials are continual springs of carbon, aramid or glass fibre impregnated by resin. The main construction change of the machine compared to commercial available solutions is the use of linear motor as a frame element instead of roller screws or toothed chain. Linear motors have higher dynamics of the movement and they can reach higher speed compared to other solutions, which guarantee increase of the machine productivity. The main importance is put not only on the functionality but also on the low price of this solution. The 3D model of the mechanism is created in the program Inventor 2009.
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NNTP Server as a Windows Network Service
Loupanec, Josef ; Ráb, Jaroslav (referee) ; Očenášek, Pavel (advisor)
This work includes specification and analysis of requirements, design and implementation of the internet news server. The server controls newsgroups and associated news. It provides availability of the articles by NNTP protocol and HTTP protocol (by web interface). The server supports a user authentication and an optional proxy mode, when all NNTP requests are resent to another remote NNTP server. A mechanism that provides news-downloading from remote NNTP servers and performs distribution function is included too. The application is designed to run on MS Windows NT (and higher version) as a NT service. The server is configurable by a graphic user interface. The work also includes theoretical information needed for successful accomplishment of the above-mentioned requirements.
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Design and implementation of 3D printer with network printing support
Špringer, Radek ; Hošek, Jiří (referee) ; Krajsa, Ondřej (advisor)
The goal of this thesis is to design a 3D printer type delta. To describe 3D printing technologies used by this printer, basic printer features and commercially available material used at the print and its comparison. To define all hardware components, which are necessary for construction of the 3D printer type delta. To create a proposal and construct an expansion board to which all hardware components of the printer will be connected. To optimize the print space heating and cooling of the printout. To extend the 3D printer with a Web server, which will ensure the network printing possibility.
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Generator of illegitimate network traffic
Blažek, Ondřej ; Smékal, David (referee) ; Blažek, Petr (advisor)
The diploma thesis deals with the problems of DoS/DDoS attacks and development of a tool, in C lanugage, for generating them. In the first chapter the principles of DoS attacks targeting the internet and transport layers of ISO/OSI model are described and also according to their characteristics divided. Selected attacks on the application layer are also described here in detail togehter with protocols which they are based on. In the following chapter there has been created a comparison of freely available tools, which could be used as a attack generators. The practical part is dedicated to a development of a tool for DoS attacks, especially design, general description and usage. Further there is a summary of the newly created library, including results of web server testing, and extensions of a web interface, which is part of the developed tool.
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Network load generators
Kubík, Pavel ; Koutný, Martin (referee) ; Pelka, Tomáš (advisor)
The aim is to create, test and describe the network load generator for server-client connection type. It´s used language C++ under Linux. It was also used socket and multithreading programming. Load on the server is done by sending HTTP requests. The load generator have different adjustable parameters and displays the test statistics. In this work is described mechanisms wich are used, by the application, to load. Testing was done on one server with a different size of the target file.
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Control of microcontroller via Internet
Kulig, Tomáš ; Fedra, Zbyněk (referee) ; Frýza, Tomáš (advisor)
The title of my bachelor’s thesis is Control of microcontroller via Internet. The result will be a web page (through this page it will be possible to communicate with a development board) and a design of development board itself. Due to complexity of TCP/IP protocol, I am going to use a simple operating system Nut/OS with the converter RTL8019AS (enabling transfer Ethernet to ISA bus) and with microcontroller ATmega128.
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