"This thesis presents an implementation of the Finite Difference Time Domain (FDTD) method on a massively parallel computer system, for the analysis of electromagnetic phenomenon. In addition, the implementation of an efficient mesh generator is also presented. For this research we selected the MasPar system, as it is a relatively low cost, reliable, high performance computer system. In this thesis we are primarily concerned with the selection of an efficient algorithm for each of the programs written for our selected application, and devising clever ways to make the best use of the MasPar system. This thesis has a large emphasis on examining the application performance."

Literary review, according to theoretical and experimental researches, it was noticed that electromagnetic fields of industrial frequency influence the human and environment. Power force of low frequentative electromagnetic beaming is little. However electromagnetic beams of these low frequentative domains have clearly expressed electrical and magnetic fields which affect the separate parts of human body. The most sensitive parts to the effect of electromagnetic fields are the nervous system and the neuroendocrine system. The biggest sources of electromagnetic fields are the domestic appliances, the installations of electricity transmission, transference and the distributing installations in residential and working places. Electromagnetic fields are generated with electric installations and spread in space by 1/r3; 1/r2 and 1/r law. It is typical of the value change of electric and magnetic fields. Parameter value of electromagnetic fields is solved with electricity installations tension, stream and the location of analyzed point in point of installations. Summing up the wide energetic net of our country, the fact of usable electric installations (which create electromagnetic fields in residential and working places) assume the marked social signification, there is posed the opportunity to forecast the available values of low electromagnetic fields effect, and to forecast means to remove it.

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.

This discourse deals with a theoretical study of the radiation passage through a diffraction screen with non-zero size in the propagation direction of the radiation, i.e. the radiation passage through a three-dimensional object. Without any loss of generality, we solve the problem for cylindrical cavity in metal. The task exceeds evidently standard scalar theory of diffraction, thus we solve the problem using a waveguiding theory. Following the principles of the electromagnetic theory, we derive required formulae to determine mode distribution at the entry of the cavity. Further, we solve numerically the radiation propagation through the cavity, then we actually seek for radiation distribution at the very end of the cavity. This yields, with a help of the discrete Fourier transform, an intensity distribution of Fraunhofer diffraction pattern, consequently compared with an intesity distribution of the radiation pattern of Fraunhofer diffraction on infinitely thin circular opening having the radius of the cylinder cavity under study. A comparison of such patterns results to a conclusion, that the cavity length has a significatn influence on the diffraction pattern and more importantly, that the scalar diffraction theory appears incorrect for a coherent light passage through cavities longer than their radius squared. Similarly, the same conclusion is inversely proportional to a wavelength of the interacting radiation. Finally, we mention an existence of the so called "focal regime", when the radiation repeatedly exhibits roughly one order increased intensity on the symmetry axis of the cavity.

Jednoduché dvojrozměrné anténní zářiče, které slouží jako stavební bloky anténních polí, jsou analyticky analyzovány v časové oblasti. Jako hlavní nástroj pro analýzu je použita Cagniard-DeHoopova metoda. Je ukázáno, že zvolený přístup umožňuje získat přesné vzorce v časové oblasti v uzavřeném tvaru, které jasně demonstrují vliv vstupních parametrů a objasňují fyzikální podstatu pulsního elektromagnetického vyzařování. Dané numerické výsledky ilustrují důležité aspekty pulsního elektromagnetického záření v rozličných konfiguracích problémů. Získané výsledky jsou užitečné pro efektivní návrh anténních polí, které jsou buzeny pulsními signály.

The aim of this thesis is to simulate the action of electrodynamic forces on current carrying path and a movable contact of the circuit breaker OEZ Modeion BH 630NE. For the calculation there is used the simulation program Ansys Maxwell. The first part is devoted to theoretical analysis of electromagnetic forces on a conductor in a magnetic field. Further I discuss the constructional design of the circuit breaker itself, especially the current path and the contact mechanism. In the next part there is (with using program Autodesk Inventor) created a simplified 3D model of the current path including an arc chamber. With program Ansys Maxwell then there is performed simulation of the acting of forces in each mode. This is magnetostatic and transient analysis for symmetrical and asymmetrical flow of the fault current. In conclusion the results obtained are evaluated and processed in the tabular way.

<div>Over the past few decades, the focus of wireless communication technology has been shrinking in terms of coverage area. It started with WMAN (Wireless Metropolitan Area Network), moved to WLAN (Wireless Local Area Network) and WPAN (Wireless Personal Area Network), and is soon expected to move to WBAN (Wireless Body Area Network). Wireless positioning/location services present a perfect analogy to wireless communication services. It started with the use of GPS (Global Positioning System), is moving to Local Area Positioning System (LPS) and will be soon moving to Personal and Body Area Positioning Systems (BPS) in the future.</div><div><br></div>This thesis presents the development of a high-speed and high-accuracy wireless magnetic positioning system which can locate the position and orientation of the sensor in real-time with a sub-mm level accuracy in body area. The system consists of an antenna (transmitter) and one or multiple sensors (receivers). The sensor module consists of a tri-axis AC magnetic field sensor, an orientation sensor, a micro-controller and a communication unit. The system is robust to multi-path, low-power, low-cost and provides complete location privacy to its users. Possible implementations of this technology could be in the field of gaming, media entertainment, security, robotics, bio medical, motion-capture and home-automation. The ultra-low latency of the system and its ability to track the sensor anywhere around the antenna without occlusion makes it a perfect candidate to be used as a Virtual/Augment Reality (VR/AR) input device.

No description available.

[pt] As ferramentas de perfilagem eletromagnética para poços e túneis têm sido objeto de interesse da engenharia por muitas décadas devido às suas aplicações para a exploração de petróleo. A fim de obter uma avaliação precisa de uma formação geofísica, uma ampla variedade de métodos de eletromagnetismo computacional foi desenvolvida. O alto custo em termos de recursos computacionais para o procedimento da discretização espacial é um ponto negativo desses métodos tradicionais. Esta pesquisa tem como objetivo explorar novas abordagens semianalíticas para analisar a propagação de campos eletromagnéticos em meios anisotrópicos compreendendo camadas planares. Apresentaremos uma formulação matemática para os campos eletromagnéticos de uma fonte solenoidal em termos de um somatório de autofunções modais. O método proposto permite a análise de cenários geofísicos análogos aos do Pré-Sal brasileiro, onde rochas carbonáticas de alta condutividade são predominantes. Além disso, o efeito das formações do pré e pós-sal nas ondas eletromagnéticas pode ser facilmente incorporadas no nosso modelo. Apresentaremos resultados numéricos de validação, que demonstram o potencial da abordagem proposta neste trabalho para modelar sensores geofísicos de forma computacionalmente robusta e eficiente. / [en] Electromagnetic well-logging tools have been subject of interest for many decades due to their applications in oil exploration. In order to obtain accurate formation evaluation, a wide variety of numerical methods have been developed on Computational Electromagnetics. The high cost in terms of computational time and resources of these methods for the spatial discretization procedure is a negative point of these traditional methods. In this work, we will explore new semi-analytical approaches to analyze the propagation of electromagnetic fields in anisotropic media comprising planar layers. We will present a mathematical formulation for the electromagnetic fields due to a solenoid source in terms of a sum of modal eigenfunctions. The proposed method allows the analysis of geophysical scenarios similar to those of the Brazilian Pre-Salt, where high conductivity carbonate rocks are predominant. In addition, the effect of pre- and post-salt formations on electromagnetic waves can be easily incorporated into our model. We will present numerical validation results, which demonstrate the potential of the approach proposed in this work to model geophysical sensors in a computationally robust and efficient way.

Research on 6G telecommunication networks has been initiated. Among all potential technology components, the distributed multi-input multioutput (D-MIMO) technology is one of the promising enablers. Due to the new technology solutions, additional methodologies for assessment of electromagnetic field (EMF) exposure need to be developed. This study provides methodologies and results for EMF exposure from D-MIMO operating at 3.5 GHz in an indoor industrial environment using CST Studio Suite®. The D-MIMO access points (APs) are mounted on the 7 m ceiling. The EMF exposure is statistically evaluated in a subvolume that extends up to 2.5 m above the floor, using receiving antennas that are pseudorandomly distributed over space. The resulting EMF exposure levels of DMIMO were compared to those of a ceiling-mounted reference massive MIMO array, considering different receiving antenna orientations and AP densities. The results from zero forcing (ZF) precoding were compared to those based on maximum ratio transmission (MRT) precoding. For a total radiated power of 1 W, the 99th-percentile power density values in the D-MIMO deployment are found to be 2.9 mW/m2 or lower, in all studied cases using the MRT-based precoding. This is about 0.03 % of the EMF exposure limits for the general public specified in international guidelines. The corresponding results from the reference massive MIMO array are found to be 7.7 mW/m2 or lower. In the ZF precoding case, the total radiated power and the EMF exposure levels are reduced and the reduction in the D-MIMO deployment is found greater than the reduction in the massive MIMO array. At the 99th-percentile, the power density value is found to be 0.090 mW/m2 in one of the cases of D-MIMO deployment and 5.1 mW/m2 in the corresponding case with the massive MIMO array. The effects of receiving antenna orientations and AP density on the EMF exposure levels are found to be small. This work benefits further studies by providing estimates of realistic EMF exposure and by demonstrating a simulation method for EMF exposure assessment for D-MIMO. / Forskning inom 6G har påbörjats. Bland de möjliga teknologierna för 6G är distribuerad multi-input multi-output (D-MIMO) ett lovande koncept som möjliggör 6G. På grund av den nya teknologin förväntas nya metoder behövas för bedömning av exponering för elektromagnetiska fält. I denna studie utvecklades och användes metoder för simulering av elektromagnetisk exponering från D-MIMO på frekvensen 3.5 GHz i en industriell inomhusmiljö i CST Studio Suite®. En statistisk behandling av exponeringsnivåer utfördes för pseudoslumpmässiga fördelningar av mottagarantenner. Antennerna i nätverket var placerade intill taket på 7 meters höjd och exponeringsnivån mättes i en delvolym som sträcker sig från golvet till 2.5 m höjd. Jämförelser gjordes med massiv MIMO som referens, och mellan olika vinklar hos mottagarantenner och tätheter av uppkopplingspunkter i nätverket. Antennloberna riktades med zero forcing (ZF) och en metod baserad på maximum ratio transmission (MRT). Med MRT och en total utsänd effekt på 1 W, var 99th-percentilen för elektromagnetisk fältintensitet från D-MIMO 2.9 mW/m2 eller lägre i alla studerade fall, vilket är 0.03 % av den internationella referensnivån för elektromagnetisk exponering. Motsvarande nivå för massiv MIMO var 7.7 mW/m2 eller lägre. Med ZF reducerades den totala utsända effekten och reduktionen i exponeringsnivån var större för D-MIMO än för massiv MIMO. I ett av de studerade fallen var 99th-percentilen från D-MIMO 0.090 mW/m2 , och motsvarande nivå för massivt MIMO var 5.1 mW/m2 eller lägre, Effekterna av vinklar hos mottagarantenner och tätheter av uppkopplingspunkter var liten. Detta arbete bidrar till framtida studier inom ämnet genom att ange uppskattningar av realistiska exponeringsnivåer och genom att demonstrera en metod för simulering av exponeringsnivåer för D-MIMO.