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  • 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.
1

Ve větru umělecké reflexe větrných a elektromagne tických jevů / In the wind: Artistic reflection of wind and electromagnetic phenomena

Kindernay, Michal January 2012 (has links)
The thesis deals with artworks, which are based on natural electromagnetic and eolian processes. It analyzes how these elementary phenomena define a topic and work of selected artists. Earth and wind as the driver? Creative tool? The score? The study concerns the historical, artistic and ecological contexts. It examines issues in the field of audio, visual and new media art.
2

Vliv externích elektromagnetických polí na funkci snímačů otáček / Influence of external electromagnetic fields to function of speed sensors

Jehlář, Zbyněk January 2009 (has links)
This thesis is focused influence of external electromagnetic fields to function of speed sensors. In this work is created summary of individual principles speed sensors and possible sources electromagnetic fields.
3

Využitie spektrálneho merania pre hodnotenia stavu porastu obilnín

Palágyi, Alexander January 2018 (has links)
The diploma thesis is focused on processing and statistical evaluation of data obtained by using sensors measurement and vegetation sampling, also provides a literary overview on the use of crop sensing in plant production. The aim of the thesis was to analyze the data, to create an assessment of economic efficiency and to assess the possibility of utilization of the monitored sensors in on-farm conditions.Formula clause:PALÁGYI, A. Utilization of the spectral measurements to assess the state of the cereal crops. Diploma thesis. Brno: Mendel University in Brno, 2018
4

Modelování elektromagnetických polí v biologoických tkáních / Electromagnetic field mapping in biological tissues

Bereznanin, Martin January 2010 (has links)
The main objective of this study is to learn about the theory of electromagnetic field and to create a model of propagation of ultra short waves in a biological tissue. Next point of this paper is to determine a specific absorption rate (SAR) using a valid sanitary standard. A particular model solution was realized in a model environment of the program Comsol Multiphysics 3.5. A human head and a cellular phone with an intern antenna were successfully created in this model environment. First of all were entered appropriate parameters which led to a successful representation of the distribution of electric field intensity. A value of specific absorption rate taken by a biological tissue was determined in the next step. This value was compared to the value listed in a valid sanitary standard to prevent its overrun. A development of a temperature in a biological tissue was determined as well, according to a six minutes long interval stated in a valid sanitary standard.
5

Hvizdové vlny pozorované družicí DEMETER / Whistler waves observed by the DEMETER spacecraft

Záhlava, Jan January 2016 (has links)
Although lightning-generated whistlers have been studied for nearly a century, there are still questions to be answered. It is clear that, at least in a certain frequency range, these waves significantly contribute to the overall wave intensity in the inner magnetosphere. They also influence distribution functions of energetic particles in the Van Allen radiation belts. Thanks to the on-board implemented neural network for automated whistler detection, we can relate electromagnetic wave and energetic particle flux measurements performed by the low-altitude DEMETER spacecraft with the number and dispersion of whistlers detected during a certain time interval. We distinguish the cases with high and low whistler occurrence and we use this information to determine the overall effect of lightning-generated whistlers. Powered by TCPDF (www.tcpdf.org)
6

Český trh mobilních operátorů očima Ronalda Coase / Czech mobile providers market through the eyes of Ronald Coase

Benešová, Tereza January 2012 (has links)
The diploma work is focused on situation and function of Czech mobile providers market. The theoretical background is based on Ronald Coase's findings. The functionality of theoretical hypothesis is verified and further discussed on the basis of foreign telecommunication markets. Different real economics provide valuable experience concerning identification of possible assets and problems. The acquired information is consequently used for analysis of Czech mobile market. Next to the evaluation of the current situation the focus is given to the planned auction of frequencies. Conditions of this auction are described and the potential influence to future Czech mobile providers market is monitored.
7

Dynamická elektromagnetická pole v Kerrově prostoročase / Dynamic elektromagnetic fields in the Kerr spacetime

Skoupý, Viktor January 2019 (has links)
In this thesis we study a test electromagnetic field in the vicinity of Kerr black hole and with methods of extraction of its rotational energy. We are investigating a process in which a particle moves in an electromagnetic resonator around Kerr black hole. The energy of the particle is transferred to the electromagnetic field and the particle falls into the black hole with negative energy. We begin with the derivation of Maxwell's and Teukolsky equations and their numerical solutions. We derive a boundary condition for an electromagnetic field on a spherical mirror around the black hole, find the field that satisfies this condition, and describe the procedure for numerical calculation. Next, we calculate the trajectories of charged test particles in such a field and find particles that fall into the black hole with negative energy. We have found that it is possible for the particle to fall into the black hole with the energy of −124% of its rest mass, and the parameters of the electromagnetic field and trajectory of the particle need to be carefully selected.
8

Study of electromagnetic emissions recorded by the DEMETER satellite / Studium elektromagnetických emisí pozorovaných družicí DEMETER

Píša, David January 2012 (has links)
David PÍŠA Study of electromagnetic emissions recorded by the DEMETER satellite Abstract : This thesis presents results based on wave measurements performed by the DEMETER space- craft. This French spacecraft was operating between 2004 and 2010 at the altitude of ∼660 km. We focus on measurements of the electromagnetic waves and plasma density in the vicinity of imminent earthquakes. In the first part, we present a study of plasma density variations in the vicinity of a very powerful earthquake in Chile (Mw 8.8) which occurred on February 27, 2010. Data recorded before the main shock along orbits close to the future epicenter showed increasing plasma den- sities. A statistical analysis using 4 years of data to monitor density variations under similar conditions has been performed. This study shows that a large increase of the plasma density is very uncommon at this location. In the second part, a statistical study (∼6.5 years) of variations of VLF wave intensity is shown. We have analyzed all available data measured close (in time and space) to large earth- quakes (M≥5). Data related to more than 12000 earthquakes have been compared with an unperturbed background distribution. We confirm the previously reported results of a statis- tically significant decrease of the wave intensity at frequencies of about...
9

Měření rádiové sítě v závislosti na profilu krajiny / Measurement of radio networks, depending on the profile of landscape

PEČINKA, Miroslav January 2014 (has links)
This thesis describes a brief history of radio and electromagnetic waves from a physical point of view. It focuses mainly on radio waves in the VHF and subsequent construction of a radio network in this band. It uses the knowledge of the writer of this wavelength. This thesis is intended as a guide for fellow author.
10

Elektromagnetické výkonové aktuátory / Electromagnetic power actuators

Kadlecová, Lucie January 2018 (has links)
This master thesis focuses on literature research of problematics linked to power actuators working on electromagnetic principle to accelerate metal projectiles. It’s goal is mathematical analysis and constuction of selected type of electromagntic power actuator – induction coilgun

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