|
|
Turbocodes and their application in telecommunication systems
Trčka, Tomáš ; Křivánek, Vítězslav (referee) ; Němec, Karel (advisor)
This Diploma thesis deals with Turbo code problems. The Turbo codes belong to the group of error correction codes, sometimes referred to as forward error correcting (FEC) codes or channel codes. This thesis can be thematically divided into two basic parts. The first part describes turbo code encoder and decoder block diagram with the illustration of two most frequently used iterative decoding algorithms (SOVA and MAP). The end of this part contains best known turbo codes, which are used in present communication systems. The second part pursues simulation results for the turbo codes using Binary Phase Shift Keying (BPSK) over Additive White Gaussian Noise (AWGN) channels. These simulations were created in the MATLAB/SIMULINK computer program. It will be shown here, that there exist many different parameters, greatly affecting turbo codes performance. Some of these parameters are: number of decoding iterations used, the input data frame length, generating polynoms and RSC encoders constraint lengths, properly designed interleaving block, decoding algorithm used, etc.
|
|
|
Local IR spectra measurement system
Pospíchal, David ; Trčka, Tomáš (referee) ; Škarvada, Pavel (advisor)
The diploma thesis deals with the design of a system for measuring infrared spectra from local areas of samples. The theoretical part describes the electromagnetic waves and related phenomena. Furthermore, the semiconductor junction and solar cells are discussed. The following is a basic description of line spectrometers. In the practical part, a suitable arrangement of the whole system, collimator design, and especially the core of the whole work, ie control software and signal processing, are proposed.
|
|
|
Research of a Cutting Tool with a Diamond Active Part
Trčka, Tomáš ; Mrkvica, Ivan (referee) ; Chladil, Josef (referee) ; Polzer, Aleš (advisor)
The submitted dissertation is focused on research in the field of milling tools with a diamond active part when machining one of the difficult-to-machine materials (Ti-6Al-4V). The first chapters are dealing with a theoretical analysis of a given workpiece material and polycrystalline diamond (PCD) as a super-cutting material. One of the theoretical chapters is also focused on tool sharpening technologies, for which the hardness of a diamond is no longer a crucial factor. The main part of the dissertation is the design, construction and production of tools taking into account the technological design, along with the application of modern trends and technologies enabling innovation and progressive design – from the perspective of macro/micro tool geometry and insert sharpening technology. The research was focused on the application of own inserts on the insert rake face and specific sharpening technologies EDMG, WEDM and LASER. One modification of the face of the PCD insert with a laser was subsequently applied to prototype circle segment end mill. Detailed analysis of manufactured tools and workpiece material was performed by electron, optical and digital microscopy. The measured parameters in the subsequent analysis of the machining process were force loading, tool wear, temperature measurement using a thermal imaging camera and analysis of the machined surface in the form of microhardness and roughness measurements.
|
|
|
Measurement and checking of dimensions in grinding operations
Kovařík, Michael ; Varhaník, Matúš (referee) ; Trčka, Tomáš (advisor)
The bachelor thesis deals with the topic measurement and checking of dimensions in grinding operations. To introduce the issue there is in the introductory part of the work a brief characteristic and distribution of particular finishing operations. Emphasis is put on grinding that is the main subject of this work. In connection with grinding there are mentioned mainly basic abrasive materials and achieved parameters of ground surface. Then the work focuses on measuring instruments that are used for evaluating surface structure, gauges that are used for measuring and controling longitudinal dimensions and on basic distribution and description of chosen jigs. In another part are introduced conditions for operator qualifications in the are of grinding technology. In conclusion of this work is chosen a component on which is applicated chosen grinding, the solution is analytical. After it follows evaluation.
|
|
|
Remote fault monitoring system
Jarůšek, Jakub ; Trčka, Tomáš (referee) ; Škarvada, Pavel (advisor)
In practice, optical non-contact measurement of distance and displacement is divided into various methods that use a different parameter of the optical (light) signal. Some methods are explained in the work. The triangulation method is described in more detail. This method is used to measure and monitor the displacement of geological faults. For this monitoring, a low-budget device is designed, which uses lasers and a sensor to determine the displacement of the measured object in a certain time interval. The whole system will serve as verification of data measured by magnetoresistive sensors.
|
|
|
SinuTrain 4.8 software tools for NC programming of five-axis milling
Beháň, Jakub ; Trčka, Tomáš (referee) ; Polzer, Aleš (advisor)
The diploma thesis deals with preparing the production process of the winning prize, which contains a selection in the form of a hyperbolic paraboloid in its upper part. The work is divided into four main chapters. First of all, the introduction part of the diploma thesis presents the possibilities of programming in the Sinumerik control system. Next, the mathematical requirements of the selected surface - hyperbolic paraboloid - are explained. The practical part consists of creating an NC program where all the theoretical knowledge from the introduction is applied. Finally, the diploma thesis ends with an economic evaluation of the selected element.
|
|
|
A study of cutting forces during the turning process and their measurement
Piroš, Viktor ; Trčka, Tomáš (referee) ; Polzer, Aleš (advisor)
This bachelor’s thesis is structured as a literature search. Its target is to show a complex look at the problematics of force load in turning process. In the beginning, the thesis is focused on brief characteristics of turning process and tool geometry as a one of the main aspects influencing the force load in the machining system. Furthermore, the thesis deals with problematics of force load creation and its dependence on basic cutting parameters. Second part of the thesis is dedicated to the options of force load measurement in turning process and works out an illustrative example of numerical evaluationof measured data with basic statistical indicators in detail.
|
|
|
Design of a shaft of single stage gearbox machining
Fiala, Dominik ; Trčka, Tomáš (referee) ; Varhaník, Matúš (advisor)
This bachelor thesis deals about design of machining single-stage gearbox shaft. The thesis consists of five main parts. The first part focuses on constructional-functioning characteristic of single-stage gearbox shaft. The second part focuses on shaft component analysis. The third part focuses on 3D model and component drawing. The fourth part focuses on preparation of TPV documentation and the last part is the evaluation of the design.
|
|
|
Technology design for screw connection for extreme loads
Václavek, Jan ; Trčka, Tomáš (referee) ; Kalivoda, Milan (advisor)
Screw connections are a commonly used method of joining two or more components that are loaded with different types of loads during their operation. Screw connections are in some cases extremely stressed. The topic of the bachelor thesis is the introduction of potential types of extreme load on a screw connection and acquaintance with a specific case of an extremely stressed screw connection. A design of the production process is created for the discussed case and the manufactured components are evaluated in terms of assembly and service life.
|
|
|
Local IR spectra measurement system
Pospíchal, David ; Trčka, Tomáš (referee) ; Škarvada, Pavel (advisor)
The diploma thesis deals with the design of a system for measuring infrared spectra from local areas of samples. The theoretical part describes the electromagnetic waves and related phenomena. Furthermore, the semiconductor junction and solar cells are discussed. The following is a basic description of line spectrometers. In the practical part, a suitable arrangement of the whole system, collimator design, and especially the core of the whole work, ie control software and signal processing, are proposed.
|
guest ::
RSS feed.