National Repository of Grey Literature 125 records found  beginprevious97 - 106nextend  jump to record: Search took 0.01 seconds. 
The Optical Fibre Dispersion Effects on Multiplex Transmission Systems
Kyselák, Martin ; Filka, Miloslav (advisor)
This doctoral thesis deals with present trend to turn up the bit rate of the optical fibres making use of wavelenght multiplex systems. There are new theoretical and practical problems caused by the new technologies. Except the known modal dispersion there exist problems caused by chromatical and polarization mode dispersion. In the opening of the thesis the known effects, which influence the payload signal, are introduced. The polarization mode dispersion has the main attention. Within the scope of this thesis there has been programmed the statistical calculator which can analyses the measured values of differential group delay by Monte Carlo calculation. Next meaningful output is the designating application of the optical routes. It is possible to mathematicaly unambiguously define the polarization mode dispersion by Jones, Stokes and Poynting vectors. This complicated calculations are mechanized and in the simulation application make possible to simulate the signification of the PMD influence at different input parameters. The thesis includes the study of the PMD modulation format impact with the results of simulations and confrontation with other scientists results. The significant output are the final practical results examinations, which can be implemented thanks to the possibility of using the FTB-5500B measuring device.
Active Compensation of Tool Deflection
Zarboch, Jaromír ; Marek, Jiří (referee) ; Březina, Tomáš (advisor)
This paper deals with design of tool deflection compensation system for milling spindle C1, provided by company TOSHULIN, a.s. A simplified simulation model of the spindle supplemented by compensatory elements was built by using programs ANSYS, MD ADAMS, Matlab/Simulink. As action elements there were use three piezoactuators each controled by PID controler. Efficiency of this compensation system was verified based on performed simulations.
Dispersion effects in high-speed optical networks
Filip, Tomáš ; Šporik, Jan (referee) ; Tejkal, Vladimír (advisor)
This bachelor’s thesis is focusing on optical transmission principal, its transfer mediums and furthermore also with focusing on its advantages and disadvantages. First half of this thesis focuses on adverse influences, which affect signal transmission in optical networks, on dispersion influences, especially on Polarization Mode Dispersion (PMD). Second half of this thesis deals with measuring of properties of optical fibers, largely chromatic and polarization mode dispersion, used methods and its principals. Furthermore, there are mentioned current compensation possibilities. The seventh chapter deals with optical route simulation in OptiSystem and testing chosen compensation methods for bit rate 40Gb/s. In the last chapter there are elaborated results of real optical route measurements for Masaryk University.
Load flow analyses of reactive power in distribution system
Krátký, Michal ; Kašpírek,, Martn (referee) ; Topolánek, David (advisor)
This thesis is focused on issues with transmission of reactive power though the distribution line of E.ON area. The goal is to find out where and in what rate are overflows of reactive power and to project the correctional steps to minimize this overflow. In this solution, there were used data of dispatcher measurement, which were processed by created source code in Matlab. The processing was analyzed for final conclusion. There were discovered shortages in overflow of reactive power in transfer between distribution and transmission line and in unsuitably regulated capacity power factor in Planá power plant and wrong automatic regulation of turns in 440/110kV substation Dasný. The action to minimize overflows of reactive power was projected by decompensation reactor placed in T101 and T102 transformers in substation Tábor.
Generating of the fault record for protection and fault indicator testing
Bažata, Petr ; Jinderle, Pavel (referee) ; Topolánek, David (advisor)
The thesis is focused on a presentation of a model creating which is followed by the simulation of running real network with using the compensatory elements to minimize the incurred failures. This thesis is divided into two thematic parts – the first theoretical one deals with the basis structuring of short-circuit faults and more detailed study of ineffective ground connection. Particularly this part attends to the problematic of a network description with extinguishing suppression. Using the compensation minimizes the impact of the failure state. A short-term fixing of a resistor improves the function of the ground-fault protection and helps to detect the outgoing section damaged by the defect. Furthermore the thesis indicates simulation programs, compares them and chooses the most suitable one for the next practical part. This is focused on a simulation of a real network run, together with elements for an effective defect-reduction or easier detection of ground connection. As a simulation of a ground short-circuit is the model in the end of the thesis modified on a network with an effective grounded bundle. Testing of the model correctness and creating a record of a model using the real ground protection settings is also one part of this thesis.
Optimalization of Induction Furnace Operation in foundry Vsetín
Trachta, Jiří ; Nowak, Stanislav (referee) ; Lázničková, Ilona (advisor)
The aim of this work is optimalisation of induction furnace in foundry for company PROMET FOUNDRY a.s. The company has two induction furnances. There are installed as identical construction. They have 2 modes of operation. First mode is founding and second mode is mode, where is temperature in maintain mode. Only one induction furnance can work in the founding mode at a time though. Inducion furnances are in the single-phase connection and they cause unbalance in the distribution network. Near the foundry there is a small network area whitch it is operated by company Zásobování teplem Vsetín a.s. The consumption of electrical energy in foundry so big, that in the year 2009 was made elaborate for Zásobování teplem Vsetín a.s. It was write at Laboratoře diagnostiky výkonů (Laboratory of performance diagnostics), which is a part of Electrotechnic Department at Technical Univarsity of Ostrava. The ordered study was named “Verification of causes of increased reactive energy consumption during transition from electricity delivery to electricity consumption”. The conclusion of this assignment confirms that in distribution network in the Jiráskova area in Vsetín there is unbalance of electrical energy and there is high part of reactive power. The next conclusion is crucial to find the customer who made the unbalance and to set relevant remedy. The last step will be the identification whether such device can actually be effectively balanced. It was subsequently proved that the Promet Foundry was causing the unbalance and that balanced consumption would be reasonable. Promet Foundry thus addressed Autel a.s. company with an inquiry to make a study of removing the causes of the unbalance which is caused by current induction furnaces operation at a minimum possible cost, least possible influence on the performance and minimum construction changes concerning the building. In this thesis there will be some topics. The result of which will be introducing of used heating technology, introducing of company and of effective plant performance and subsequent suggestions of possible unbalance removal or reactive power decrease. Several ways which are being implemented in the industry in order to balance consumption will be described. A suitable balancing plant will be subsequently chosen and its parameters will be calculated.
Utilization of MERS in heavy current engineering
Vetiška, Vojtěch ; Procházka, Petr (referee) ; Huzlík, Rostislav (advisor)
This graduation thesis is aimed in usage of MERS circuits in high-current electroengineering. The MERS circuit is a serial variable capacitor which capacity is possible to change by the help of switching of semiconductor components. On beginning of the thesis I shall acquaint you with usage of the MERS circuit. It will be sketched out their basic circuitry, the operating method, possibilities of transistors switching and calculation of the capacity capacitors for particular controlling method. On the prepared device we shall accomplish the predefined measurement. Furthermore we shall create the simulation by means of the Matlab programme. In the end we shall compare the results of the simulation with measured values.
Techniques solving the fiber optic dispersion on current optical links
Prášil, Jiří ; Pfeifer, Václav (referee) ; Reichert, Pavel (advisor)
This diploma thesis deals with analysis of current diagnostic methods of optical networks, and it is focused on optical fiber dispersion in singlemode fibers. The work starts with a describtion chromatic dispersion and polarization mode dispersion, causes of and thein influence on the transmitted signal at the beginning. There are set out principles and their appropriate use in the list of measuring methods. Furthermore, the work are given the current possibilities for compensation above dispersions. The sixth chapter deals with the measurements and simulations of real routes in the OptiSystem. There are given appropriate compensation methods for the selected route speeds in the last chapter. The simulation is performed for the bit rate 2.5 Gbit / s, 10 Gbit / s and 40 Gbit / s.
Band Gap - accurate voltage reference
Bubla, Jiří ; Petržela, Jiří (referee) ; Kolka, Zdeněk (advisor)
This diploma thesis is specialized on a design of a high accuracy voltage reference Bandgap. A very low temperature coefficient and output voltage approx. 1,205V are the main features of this circuit. The paper contains a derivation of the Bandgap principle, examples of realizations of the circuits and methods of compensation temperature dependence and manufacture process, design of Brokaw and Gilbert reference, design of a testchip and measurement results.
Erors and Uncertainties in Temperature Measurement
Jirmásek, Jakub ; Vojáček, Zdeněk (referee) ; Vdoleček, František (advisor)
Bachelor thesis is focused on sources of temperature measurement uncertainties and their expressing. There is a basic description of the temperature as a physical quantity and its scale. The study describes some kinds of thermometers, focusing primarily on electric thermometers which have a dominant position in the field of automation and regulation. Further the importance of measurement uncertainty is described and its expressing. More space is devoted to the importance of different sources of uncertainty and possible compensation. Finally there is an example of determining the measurement uncertainty.

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