National Repository of Grey Literature 51 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
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.
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.
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.
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.
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.
Measurement module with power over fiber
Dvorský, Pavel ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
The thesis deals with design and construction of low-power measurement device with power over optical fiber. This device should measure input signal in range of 50 mV to 50 V and the results of measurement sent through optical fiber into sensing module.
Basic characterization of selected samples of animal feeds
Svoboda, Ilona ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
The aim of the diploma thesis was to choose poper parameters for a quick and simple characterization of animal feed, to verify working procedures and to apply these on chosen samples. Within the scope of this work, samples of animal dog feed produced in a private company „Adamkovy tlacenky“ were analyzed. The feed is in the form of brawn, stored in artificial casing; it consists of up to 80% of animal components and up to 20% of vegetable components, while the rest of the weight is the pork gelatine. The feed does not contain preservatives, colourings as well as any other chemically produced additives. For the analysis three formulas were chosen: "Hovězinka", "Kuřátko" and "Srdcovka", the composition of which is protected by the patent. The choice was made to include samples of different composition. The content of raw crude protein, fat, fibre, dry basis, and ash was determined. The obtained values were compared with the standards for feed normally utilized by the feed industry. The results will be used to improve the formulas and to develop new types of feed.
Study of the properties of concrete with reinforcement, intended for the production of concrete egg-shaped tubes
Šťastný, Antonín ; Hela,, Vlastimil (referee) ; Hubáček, Adam (advisor)
This diploma thesis examines the properties of concrete with reinforcement, designed for the production of a concrete egg-shaped tubes . The stress is put on using various types of fiber reinforcements. Theoretical part is divided into 4 subsections. The topic of the first subsection is a concrete in general. Second subsection deals with various technology of production of concrete pipes. The third subsection is focused on description and summary of basic properties of concrete and reinforced concrete tubes. The last subsection deals with standardized procedures for testing concrete. Experimental part of this thesis is divided into two subsection. First subsection deals with design of a reference sample. Six different samples of a concrete were designed and their rheological properties were tested. Second subsection deals with the additi-on of various types of fiber reinforcement to the reference sample. Eight different admixtures of a concrete were added to the reference sample. Properties of these admixtures were tested in fresh and hardened state.
Strengthening steel beams using reinforcement based on FRP
Bláha, Tomáš ; Melcher, Jindřich (referee) ; Karmazínová, Marcela (advisor)
A study of an influence of strengthening steel beams using reinforcement based on FRP on a moment bearing resistance and bending stiffness. Evaluation of the theoretical calculation methods based on the performed experimental verification. Description of the production of carbon fibres and composite materials on the basis of carbon fibres.
Verification of parameters of passive optical components on short wavelengths
Látal, Michal ; Filka, Miloslav (referee) ; Vojtěch, Josef (advisor)
Semestral thesis deals with the basic theoretical knowledge in the field of optics, light propagation and optical fibers. It describes in detail the optical transmission system and its associated issues, such as the attenuation of optical fibers or differently caused dispersion. The main part of this work is a description of each passive optical elements, their production technologies and applications in optical communications. Within the optical connection its radiation sources and detectors of optical radiation are explained. The last practical part is focused on the measurement of insertion loss provided by passive optical components.

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