• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 22
  • 4
  • Tagged with
  • 26
  • 14
  • 9
  • 7
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Studium intenzitního profilu optických svazků / Optical beam intensity profile analysis

Fojtík, Jakub January 2014 (has links)
This work is focused on the study of the intensity profile of optical beams. In the first part problematics of optical beams from theoretical point of view is discussed, Model of realistically circular symmetric beam in an ideal lossless, stationary, homogeneous and isotropic medium is formed in Matlab®. The next part of the thesis deals with implementation of automatic workplace for measuring intensity profile of optical beams. Within the thesis - PCB desing of photodetector in Eagle®, is discussed. Custom application for controlling the motorized linear stage M – IMS 400 and communication with photodetector in the Microsoft Visual Studio 2010® was created.
12

Predikce sil a kvality opracování při frézování s vysokými posuvy / Prediction of cutting forces and quality of surface when milling with high feeds

Mikel, Pavel January 2013 (has links)
Theoretical study describes force analysis and quality of surface when milling. In the experiment the emphasis is on determining forces and surface quality in milling in response to changes in feed rate. Especially determination of specific cutting force kc and cutting force Fc at materials from aluminium alloy AlSi9Cu3, titanium alloy Ti6Al4V and steel C45, the used tool was a milling cutter for high feeds. In the experimental section is furthermore contained statistical evaluation data which demonstrate a certain prediction changes of cutting load and surface roughness when changing feeds.
13

Vliv exotermických obkladů na tuhnutí slitin hliníku / Influence of exothermic sleaves on solidification of aluminium alloys

Zajíček, Roman January 2015 (has links)
The master’s thesis deals with the influence of the exothermic risers on the solidification of aluminum alloys. The work is divided into three parts. The first theoretical part describes the differences of properties of cast aluminum alloys compared to other based metals, especially iron alloys. It also describes the methodology of designing risers, composition of exothermic mixtures and finally gives an overview on the simulation programs on the market, their application in foundry practice and briefly explains how to define the material in the simulation program ProCAST. The second part describes the experimental measurement of the solidification time of aluminum alloy AlSi7Mg0,3 in the sand form with exothermic riser. The final section describes the simulation of experimental measurements. Further with help of simulation software it is tried to find the general principles that have an influence on feed module rate of exothermic riser.
14

Analýza přenosu mobilního digitálního rozhlasového vysílání / Analysis of the transmission in the mobile digital audio broadcasting

Kresta, Daniel January 2016 (has links)
This thesis deals with an analysis of a system called Digital Audio Broadcast and describes its mathematical model created in MATLAB program. In the first part basic blocks of a transmitter and a receiver are analyzed along with their principles. Then different types of transmission channels for static, portable and mobile receivers are described. The second part contains description of the DAB mathematical model itself. Individual blocks are described in the order of the DAB signal path, from the transmitter through the transmission channel to the receiver side. In this part the graphical user interface is also described. In the final part the results of experimental measurements and simulations are presented.
15

Simulace vícecestného šíření vícestavových modulací / Simulation of multipah propagation of multistate modulations

Polák, Ladislav January 2009 (has links)
The diploma thesis Simulation of Multipath Propagation of Multistate Modulations is focused on the development of an appropriate algorithm in MATLAB environment, which is capable to simulate the impact of the multipath propagation on received signal (error rate) on the basis of given parameters of the transmission channels. Mechanisms and characteristics of the wave propagation in communication environment, types of digital modulations and their most important parameters are described in the first part of this thesis. The second part is focused on the simulation itself. Created GUI (Graphical User Interface) is able to display constellation diagrams of transmitted and received signals, as well as their bit error rate. It is also possible to compare these data with the data of signal, which is passed by a non-fading channel.
16

Slinuté karbidy a jejich efektivní využití / Cemented carbides and theirs effective use

Baran, Jan January 2008 (has links)
The diploma work deals with comparison of sintered carbides in product assortment of Pramet Tools a.s., Sandvik-Coromant and Ceratizit companies in term of their cutting speed, feed and depth of cut for the turning operation. The comparison of cutting parameters is made for P, M, K, N, S and H groups. For better comparison there are always two sintered carbides from each of the manufacturers mentioned for each of the groups P, M, K. They are mentioned for groups N, S and H only if they are suggested by the manufacturer.
17

Analýza vysoceproduktivního vystružování / On The Analyse of High Productive Reaming Technology

Gashkova, Irina January 2011 (has links)
Diplomová práce se zabývá analýzou technologie vysoceproduktivního vystružování. V rámci práce byly provedeny testy vystružování za různých technologických podmínek (vc=40, 60, 80, 100 m/min; f=0.2, 0.4, 0.6, 0.8 mm) na materiálu austenitické oceli DIN 1.4404 při použití vystružovací hlavicí MT3. Jednotlivé operace vystružování byly porovnány z hlediska parametrů jako tlačná síla, krouticí moment, výsledná drsnost obrobeného povrchu a dále z hlediska tvaru třísky. Následně byly vypočítány průměrné hodnoty a směrodatná odchylka naměřených parametrů. Dále bylo provedeno porovnání pomocí diagramů. Výsledky ukazují lepší kvalitu, nižší drsnost povrchu (Ra 0,37 µm) a méně zdeformovanou třísku při pomalejších řezných rychlostech (40 m/min) a menším posuvu na otáčku (0,2 mm). Výsledky také ukazují nárůst tlačné síly a krouticího momentu za uvedených technologických podmínek. Při zvyšující se řezné rychlosti vystružování tyto silové účinky klesají.
18

Modulární systém lineární osy / Modular linear axis

Chlapečka, Tomáš January 2014 (has links)
This thesis contains a structural design of linear axis with a stroke up to 800mm and a maximum load of 800N. The thesis also deals with a modular assembly system of the linear axis based on the structural design. Linear axes can be fitted with rolled, whirled and grinded ball screws with thread pitch 5, 10, 16mm and rolled trapezoidal screws on pitch 4 and 8mm. The stroke of the linear axes can be selected in the range from 200 up to 800 mm, with a maximum load of 800N in all linear dimensions. The feed of linear axis is provided by shaped rolling guide way and four trucks. The modular system offers two servo motors with direct and indirect measuring four stepper engines with indirect measuring. The thesis also includes strength and functional calculations of principal components, graphs of the possible load on linear axis in different positions , durability of the ball screws, maximum speed and feed rate of the chosen screws, data sheet, 3D model, drawings and assembly drawings of the nodes.
19

Matematické metody a úlohy v astronomii / Mathematical Methods and Exercises in Astronomy

BROM, Jiří January 2016 (has links)
The aim of this thesis is to create collections of examples for the subject Astronomy taught for students of pedagogical faculties, studying this discipline as a part of physics courses. Due to very different mathematical knowledge of students I have chosen typical and not much difficult examples oriented to several branches of astronomy. Each part of examples begins with a self-contained theoretical introduction. The difficulty rises gradually from trivial to more complicated examples. The examples are mainly focused on motions in radial gravitational fields.
20

Vývoj tlumočnických dovedností / Interpreting skills development

Rambousková, Hana January 2016 (has links)
The present thesis addresses the issue of the impact of two independent variables - speech rate and interpreters' experience - on the length of time lag in simultaneous interpreting from English to Czech. Time lag, or ear-voice-span (EVS), in simultaneous interpreting is the time difference between the input in source language and the output in target language. The study comprises of two parts. The first, theoretical part summarises the current state of research on the subject. The second, empirical part compares the average EVS in excerpts of sixty simultaneous interpreting renditions uttered by forty-nine subjects divided into two speech rate categories and three experiential categories. The aim is to find out, firstly, whether there are any differences in EVS length based on speech rate, and, secondly, how the interpreters' level of experience influences their EVS length. The first main finding is that a higher speech rate leads, on average, to a shorter EVS than an optimal speech rate; this does not, however, apply in the case of professional interpreters - their EVS length is not affected by speech rate. The second main finding is that the interpreters' level of experience influences EVS length significantly: the more experienced the subjects, the shorter their EVS on average. While evaluating...

Page generated in 0.0448 seconds