A utilização da técnica de teleterapia para tratamento de câncer tem sido usada por anos com bons resultados clínicos. Em meados da década de 90, a remoção do filtro aplainador, item que compõe o cabeçote de um acelerador linear de uso clínico, tem sido objeto de estudos por demonstrar bons resultados no tratamento de alguns tipos de câncer. Técnicas utilizadas como Radioterapia de Intensidade Modulada (IMRT) e Radioterapia Estereotáxica (SRT), mostram-se mais eficazes quando não se utiliza o filtro aplainador. A empresa Varian Oncology lançou em 2012 um acelerador linear de uso clínico capaz de operar com o filtro aplainador (FF) e sem o filtro aplainador (FFF), o TrueBeam. Os objetivos desse trabalho são avaliar a homogeneidade de dois importantes parâmetros utilizados para o cálculo de dose nos pacientes submetidos ao tratamento com esse modelo de acelerador linear, a porcentagem de dose profunda (PDP) e índice de qualidade do feixe (TPR20/10). Os dados fornecidos para a análise foram cedidos pelo Hospital Israelita Albert Einstein (HIAE), Real Hospital Português (RHP) e 3 instituições norte-americanas. Através de uma análise estatística dos dados das instituições citadas pode-se observar melhor o comportamento desses parâmetro que demonstraram-se muito homogêneos e com erros menores que 1% na maioria dos casos, confirmando desse modo que os aceleradores lineares do modelo TrueBeam mantém na maioria das vezes uma boa concordância dos parâmetros analisados. / Teletherapy, radiation therapy with linear accelerators, for cancer treatment has being used for years with good clinical results.Since the 90\'s the removal of the flattening filter, item placed at the gantry of the machine, has shown better results for the treatment of some cancers thus being extensively studied. Treatments with Intensity Modulated RadioTherapy (IMRT) and Sthereotaxic RadioTherapy (SRT) were more efficient without the flattening filter. Varian Oncology released the TrueBeam in 2012, a accelerator capable of operating with or without the flattening filter. The aim of this work is to access homogeneity of the percentage depth dose (PDP) and beam quality index (TPR20/10), two important parameters used in patient dose calculations. The data used for analysis were obtained with the Israelita Albert Einstein Hospital (HIAE), Real Português Hospital (RHP) and 3 more institutions located in the United States. The statistical data analysis allowed to observe the parameters behaviors. In general, they were very homogeneous, with errors smaller than 1% confirming the conformance of the TrueBeam accelerators.

Esse trabalho contempla o estudo sobre o estimador de mínimos quadrados obtido para sistemas lineares discretos sujeitos a ruídos aditivos e a ruídos multiplicativos em seus parâmetros. Supõe-se, adicionalmente, que os parâmetros do sistema estão sujeitos a saltos Markovianos, e que a cadeia de Markov não é conhecida. A solução do problema, sob essas hipóteses, é uma inovação apresentada nesse trabalho. Sob as mesmas hipóteses, o caso estacionário também foi contemplado, e o trabalho apresenta uma demonstração para a convergência da matriz de covariância dos erros do estimador a um valor estacionário, supondo-se estabilidade do sistema e ergodicidade da cadeia de Markov associada. Mostra-se, também, que existe uma única solução positiva semi-definida para a equação de Riccati estacionária e, ainda mais, que tal solução é o limite da matriz de covariância dos erros. A partir da introdução de uma hipótese adicional - de que os parâmetros do sistema estão sujeitos a incertezas na forma de politopos convexos - constrói-se um filtro linear dinâmico em que as iterações possuem estabilidade na média quadrática e que minimiza o limitante superior para o valor esperado do erro quadrático. Uma formulação do tipo LMI (Linear Matrix Inequalities) é proposta para a solução do problema. / This thesis deals with the linear filtering problem for discrete-time Markov jump linear systems with both additive and multiplicative noises. It is assumed that the values of the Markov chain are not available. This is the first time that a solution to the problem with these parameters is presented. By using some usual geometric arguments it is obtained a Kalman type filter conveniently implementable in a recurrence form. The stationary case is also studied and a proof for the convergence of the associated Lyapunov and Riccati like equations is presented. By adding an additional hypotesis - that the parameters of the systems are subject to convex polytopic uncertainties - it was designed a dynamic linear filter such that the closed loop system is mean square stable and minimizes an upper bound for the stationary expected value of the square error. A Linear Matrix Inequalities (LMI) formulation is proposed to solve the problem.

Les membranes et les adjuvants de filtration sont très utilisés pour la filtration des vins. Les adjuvants de filtration forment un dépôt filtrant assurant l’efficacité du filtre. Cependant ces particules ne sont pas régénérables. L’objectif de ces travaux est de proposer un media filtrant régénérable et disponible en plusieurs granulométries, afin d’être utilisé lors des différentes étapes de l’élaboration des vins. Les Rilsan® en polyamide 11 biosourcé sont étudiés et caractérisés en tant qu’alternative aux diatomites. Les résultats montrent qu’avec la gamme de Rilsan® existante il est possible d’obtenir les différents grades nécessaires pour la filtration du vin. Les distributions de tailles de particules, la formation des dépôts ainsi que les efficacités de filtration ont été déterminées. Lors de la filtration sur précouche de Rilsan® les mécanismes de rétention suivent une loi de colmatage intermédiaire des pores. Du fait de la structure non poreuse du matériau par rapport aux diatomites, leur régénération est possible et a été étudiée par hydrocyclonage. Les non-tissés ont l’avantage d’avoir de très fortes porosités ; ce qui est un atout pour obtenir des débits de filtration importants. De nouveaux media en polyamide 11 fabriqués par Electrospinning sont testés comme une alternative aux membranes actuelles, de plus faible porosité. Les diamètres de pores obtenus de l’ordre de 1,5 μm sont encore trop élevés pour envisager une stabilisation microbiologique du vin. La faible résistance mécanique des media est un frein à leur développement pour la filtration des liquides. Les perméabilités sont peu dépendantes de la dimension des pores dans la gamme testée et dépendent principalement de l’épaisseur du matériau et d’autres paramètres de fabrication. / Membranes and filter aids are classically used filter media throughout the wine making process. During filtration, filter aids form a precoat inducing the retention efficiency of the filter. However, these particles are not regenerable. The aim of this study is to find a cleanable and reusable alternative to existing filter aids, available in various grain-size distributions, in order to perform the different types of wine filtration. The Rilsan® powder, made of biobased polyamide 11, are characterized and studied as an alternative to diatomaceous earth mainly used for enology applications. Results showed that the range of Rilsan® allowed performing both rough and clarifying filtration. The particle size distribution, the granular bed deposition and the filtration efficiency were determined. During filtration using Rilsan® precoat, the fouling mechanisms follow an intermediate pore blocking law. According to their non-porous structure compared to diatomite, these particles are cleanable. Hydrocyclone process is studied in order to achieve this regeneration. Nonwovens have important porosities which is an asset to have high filtration flow rates. New filter media made by electrospinning process of polyamide 11 are tested as an alternative to currently used filtration membranes. The pore diameters measured of 1.5 μm are still too large to be used for wine microbiological stabilization. Their mechanical weakness is a brake to their use in liquid filtration applications. Water permeability is little influenced by the pore size, in the range of media tested, and depends mainly on the thickness of the media and other fabrication processes.

The availability to clean drinking water is something a lot of people take for granted today. Daily, there are about 1.8 billion people around the world that drinks water from a contaminated water source. Unfortunately, the deficiency is a fact, and about 361 000 children under the age of five die each year because of diarrheal disease (WHO, 2016a).  Earlier studies show that a biosand filter is an easy and efficient water purification method that cleans the water both physically, biologically and chemically. A biosand filter is often built using local material and is filled with sand, which makes the construction cheap and easy to repair is needed. Earlier studies have shown that this purification method can reduce waterborne disease by 99,9% with the help of a biofilm layer which develop in the top layer of the sand if the conditions are meet (CAWST, 2009). The purpose with this study was to build and evaluate a biosand filter as a water treatment method in Ghana. In total, three biosand filters was built with local material, each with different sand heights. The evaluation was done by studying the waters physical, biological and chemical properties before and after the filtration, which then was compared to the water quality standards from the World Health Organization (WHO) and Sweden. The results show that none of the three filters could produce water which met the standards for drinking water, which might be caused by the high flow of water through the filter which prevented the biofilm to grow. With the help from the results in Ghana, a new design of a water filter has been made to reduce the flow of water through the filter. Which gave a new biosand filter design with a diameter of 42 cm that, sand height of 80 cm and gravel height of 15 cm. / Tillgången till rent dricksvatten är idag något som många tar som en självklarhet. I dagsläget är det omkring 1.8 miljarder människor i världen som dagligen dricker vatten från en kontaminerad vattenkälla. Dessvärre är bristen på rent dricksvatten ett faktum, vilket gör att det årligen dör cirka 361 000 barn under fem års ålder på grund av diarrésjukdomar världen över (WHO, 2016a).  Tidigare studier har visat på att biosandfilter är en enkel och effektiv vattenreningsmetod för att rena vatten både fysiskt, biologiskt och kemiskt. Ett biosandfilter är ofta byggt med lokala material och fylld med sand, vilket gör konstruktionen billig och enkel att reparera vid behov. Tidigare studier har visat på att vattenreningsmetoden kan reducera vattenburna sjukdomar med upp till 99.9% med hjälp av ett biofilmslager som utvecklas i sandlagrets övre skikt om förhållandena är gynnsamma (CAWST, 2009).  Syftet med denna studie var att bygga och utvärdera biosandfilter som vattenreningsmetod i Ghana. Totalt byggdes tre biosandfilter av lokala material med olika sandhöjder. Utvärderingen gjordes utifrån att studera vattnets fysiska, kemiska och biologiska egenskaper före och efter filtrationen, som sedan jämfördes med vattenkvalitetsstandarder från World Health Organization (WHO) och Sverige. Resultaten visade på att ingen av de tre sandfiltret kunde producera vatten med en drickvattenstandard, detta tros bero på det höga flödet genom filtret som hindrat biofilmstillväxten. Med hjälp av resultat från Ghana har en ny design av ett biosandfilter tagits fram för att minska flödet genom filtret. Vilket gav en filterdiameter som är ungefär 42 cm som sedan är fylld med 80 cm sand och 15 cm grus.

Le problème de filtrage consiste à estimer l'état d'un système dynamique, appelé signal qui est souvent un processus markovien, à partir d'observation bruitées des états passés du système. Dans ce mémoire, nous considérons un modèle de filtrage en temps continu pour le processus de diffusion. Le but est d'étudier la stabilité du filtre optimal par rapport à sa condition initiale au-delà de l'hypothèse de mélange (fort) pour le noyau de transition en ignorant l'ergodicité du signal / The filtering problem consists of estimating the state of a dynamic, called signal which is often a Markov process, from the noisy observation of the past states. In this thesis, we consider a filtering model in continuous time for the diffusion process. The aim is to study the stability of the optimal filter with respect to its initial condition beyond the mixing (or quasi – mixing) hypothesis for the transition kernel

Practical control problems are subject to dealing with instrumentation noise and inaccurate models. These can be modelled as measurement and state noise, respectively. Nonlinear state estimators, for example a particle filter, can be used to mitigate these effects. However, they are usually computationally expensive which makes them impractical for industrial use. This text investigates using General Purpose Graphics Processing Units (GPGPU) to improve the performance particle and Gaussian sum filters by parallelizing their prediction, update and resampling steps. GPGPU accelerated filters are found to outperform non-accelerated filters as the number of particle increases. GPGPU acceleration also allows particle filters with 2^19.5 particles to be used on systems with dynamic time constants on the order of 0.1 second and for Gaussian sum filters with 2^18.5 particles to be used with time constants on the order of 1 second. The filters are applied to a bioreactor system containing R. Oryzae, where MPC control is applied to the production phase fumaric acid and glucose concentrations. The bioreactor is modelled using results from Iplik (2017) and Swart (2019). It is found that the GPGPU filters improved run times allow for more particles to be used which provides increased filter accuracy and thus better performance. This improved performance comes at the cost of consuming more energy. Thus, it is believed that the GPGPU implementations should be used for applications with complex dynamics/noise that require large numbers of particles and/or high sampling rates. / Dissertation (MEng (Control Engineering))--University of Pretoria, 2021. / Chemical Engineering / MEng (Control Engineering) / Unrestricted

The paper deals with analysis of the problems of digital signal processing and with design of the control unit for DSP and audio signal distribution to active external loudspeakers. It describes function of delta-sigma AD converters, the most widely used digital filters and Fast Fourier Transform. The processed signal will be send to external loudspeakers using an Ethernet interface. The paper also covers the design of signal processing unit's hardware and software. Achieved functions and parameters of the unit are discussed in conclusion.

This thesis is concerned with attitude estimation of small flying robots using low cost, small-sized inertial and magnetic sensors. A quaternion-based extended Kalman filter is used, which adaptively compensates external acceleration. External acceleration is the main source of estimation error. If external acceleration is detected, the accelerometer measurement covariance matrix of the Kalman filter is adjusted. The proposed algorithms are verified through experiments. Selected algorithm is implemented on STM32F4DISCOVERY development board.

The diploma work concerns on an issue of data collection of speed and electrical angle based on informations from Hall sensor with the necessary resolution for control of BLDC motor. Specifically, concenred on a section with low speed. Most of moors use Hall sensor for detecting speed and position of the rotor. At low speed section, becomes the situation when we can not determine the position of the rotor with (the) required (sufficient) resolution, this situation creates a „wince“ in the control (ripple torque). The task is to design and evaluate the possibilities of the algorithm for control and acquisition speed and rotor position with the required accuracy.

The aim of this term project was to analyze wireless indoor localization. It contains analysis of some wireless localization techniques such as Time of Arrival or Time Difference of Arrival. The paper also describes the system of SEWIO Company. Main part of the master’s thesis is description, design and implementation of the Kalman filter. The Kalman filter is used to improve two-dimensional positional data and synchronization of anchors (devices for finding a position of an object in SEWIO system). There are described a few system models for the Kalman filter.