The aim of this work is to implement digital filters into programmable gate array. The work also includes a description of the MEMS technology, including comparisons with the technology of MEMS microphones from various manufacturers. Another part is devoted to the Sigma-delta modulation. The main section is the design and implementation of digital CIC and FIR filters for signal processing of digital microphone, including simulation and verification of properties of the proposed filter in Matlab.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This Master’s thesis deals with digital decimation filter design for undersampling and filtering of sigma-delta ADC signal. Filter cascade is designed in Matlab according to given requirements and is then described in VHDL language aiming for minimum area. Implemented filter functionality is compared to Matlab-generated reference filters in created verification environment. Finally the design is synthesized in specified technology and verified on gate level.

The doctoral thesis deals with development and design of novel architectures of digital filters for low-power integrated circuits. The main goal was to achieve optimum parameters of digital filters with respect to the chip area, power consumption and operating frequency. The target group of the proposed architectures are application specific integrated circuits designed for signal processing from sensors using delta-sigma modulators. Three novel architectures of digital filters optimized for low-power integrated circuits are presented in the thesis. The thesis provides analysis and comparison of parameters of the new filter architectures with the parameters of architectures generated by Matlab tool. A software tool has been designed and developed for the practical application of the proposed architectures of digital filters. The developed software tool allows generating hardware description of the filters with respect to defined parameters.

The thesis aims to implement different digital filters such as finite impulse response (FIR), infinite impulse response (IIR) and cascade integrator comb (CIC) on the field-programmable gate array (FPGA) development board using hardware description language (VHDL). To this purpose, Intel’s systems integration tool Platform designer is used to convert the implementation to an IP core. The implemented FIR and IIR filters include different filter types such as lowpass, highpass, bandpass and bandstop. All the filters have a pipeline architecture as well as adjustable parameters such as filter order, frequency specifications and resolution. The coefficients of the filters are calculated according to the user's specifications. The calculated coefficients are verified using simulation. Furthermore the IP has been validated on hardware by the FPGA board MAX DE-10 lite. The IP is also analyzed regarding timing and power consumtion with good results. FIR filters of different types have been implemented and tested up to 501 taps with a coefficient width of 24 bits, which covered just below 50% of the available logic gates on the MAX 10-DE lite board with 50000 gates in total. The FIR filters have an option to be used with a Kaiser window with a maximum tap level of 51. Different IIR filters have also been implemented and tested on the hardware. However, the results have shown that the IIR filters do not perform so well, especially those of order higher than 6. One of the main reasons for this is the overflow caused by instability of the IIR.

(in English): This thesis deals with post-war fate of Josef Robotka the member of the second and third resistence and people who cooperated with him. It cannot be mentioned his activities during the Second World War in the Council of three but the key issue will be the engagement after 1945. I would describe his disenchantment with communist ideas while on Vorošilov military academy in Moscow, subsequently forced to return to Czechoslovakia and post-February intelligence cooperation with CIC. I will also try to bring the role of public authorities in the arrest, detention and trial. In the next section I would like to map the entire arrest of Robotka group, their imprisonment and trial. The following chapters will deal with Robotka's execution and the role of wives and close relatives of convicted persons. The work is based mainly on archival research, supplemented by memories of Vlasta Nováčková Jakubová who is Robotka's niece and close collaborator. Main question is how big the importance of the information that the group sent abroad was and what significance should they have in case of possible conflict.

Transcranial routing of signal (TCROS) was accomplished using completely-in-the-canal (CIC) hearing aids in 5 profoundly unilaterally hearing-impaired individuals. The functional gain realized by the participants far exceeded the gain predicted by measuring the acoustic output and real ear aided response of the hearing aids. The difference between predicted and functional gain increased with signal frequency and was attributed at least in part to mechanical vibration of the hearing aid in the external canal. Implications for fitting unilateral hearing loss using TCROS amplifying systems are discussed.

Bone conduction transmission and head‐shadow effects were determined with transcranial completely‐in‐the‐canal (TCCIC) CROS hearing aids. Five subjects with documented profound unilateral hearing loss and experience with traditional CROS/BICROS fittings (TCROS) were tested with a CIC hearing aid placed in their poorer ear. Peak SPL was measured at the tympanic membrane and ranged from 105–115 dB SPL at 2000 Hz. Pure‐tone crossover thresholds and functional gain tested at frequencies from 250–8000 Hz varied considerably more than the SPL measures. The pure‐tone results indicated that sensitivity in the better ear was moderately associated with functional gain across frequency. Speech recognition was then tested in the sound field in two conditions: direct (noise in the poorer ear, speech in the better ear) and indirect (noise in the better ear, speech in the poorer ear) at S/Ns of −6, 0, +6, +12, and quiet. The TCCIC fittings were more effective than TCROS aids across S/Ns, particularly in the direct condition. In the indirect condition, the two fittings performed similarly. When data were pooled across conditions, the TCCIC aids provided better word recognition than the TCROS aids, particularly for those subjects with greater sensitivity in the better ear.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Glyphosate [N-(phosphonomethyl) glycine] is the most widely used pesticide in the world for controlling weeds in agriculture. High amounts of this herbicide and its major metabolite, aminomethylphosphonic acid (AMPA), have been found in water due to intensive use. The Ministry of Health 2914 establishes a maximum value allowed for the sum of glyphosate and AMPA at 0.5 mg L-1. The most comum method to determine these compounds requires a derivatization step for fluorescence detection. Thus, this study aimed to develop two simple and rapid methods for the direct determination of glyphosate and AMPA in water without treatment or sample derivatization steps, by capillary ion chromatography (Capillary IC) and liquid chromatography tandem mass spectrometry (LC-MS/MS). The Capillary IC method employed a capillary IonPac AS19 column (250 x 0.4 mm, 7.5 μm), a gradient elution with KOH a conductivity detector. The LC-MS/MS method used a Pursuit XRS C18 column (150 x 2 mm ID, 5 μm), an aqueous solution of ammonium hydroxide 0.01% (v/v) as mobile phase and a triple-quadrupole MS detector, operating in a selected reaction monitoring (SRM) mode. The method validation was performed by recovery experiments, evaluating accuracy, precision, linearity, limits of detection (LOD) and of quantification (LOQ). The analytical curves for glyphosate and AMPA obtained for the concentration levels 25, 50, 100, 250 and 500 μg L-1 by Capillary IC and LC-MS/MS showed r2 >0.99 for both compounds. For spiked levels of 25, 50, 250 and 500 μg L-1 recoveries were between 70 -113%, with RSD <10% for Capillary IC and 79-105%, with RSD <14% for LC-MS/MS. The method limits of detection for both glyphosate and AMPA was 8 μg L-1 and of quantification was 25 μg L-1, in both chromatographic techniques. Both methods showed good selectivity and sensitivity. Determination by direct injection of the sample, using capillary IC or LC-MS/MS proved to be efficient, simple and cost-effective tools for analysis, making it possible to monitor at levels below the maximum allowed limits for drinking water. / O glifosato [N-(fosfonometil)glicina] é o agrotóxico mais utilizado na agricultura mundial no controle de plantas daninhas. Altas quantidades desse herbicida e seu principal metabólito, o ácido aminometilfosfônico (AMPA), vem sendo encontrados em água devido ao uso intensivo. A portaria do Ministério da Saúde nº 2914 estabelece o valor máximo permitido para a soma de glifosato e AMPA em 0,5 mg L-1. O método amplamente utilizado para a determinação desses compostos é a HPLC sendo imprescindível uma etapa de derivatização para a detecção por fluorescência. Assim, este trabalho teve como objetivo desenvolver métodos simples e rápidos para a determinação direta de glifosato e AMPA em água para consumo humano, sem etapa de tratamento de amostra ou derivatização, empregando a cromatografia iônica capilar (CIC) e cromatografia líquida acoplada à espectrometria de massas em série (LC-MS/MS). O método por cromatografia iônica capilar empregou coluna capilar IonPac AS19 (250 x 0,4 mm; 7,5 μm), gradiente de eluição com gerador de KOH e detector de condutividade. Para LC-MS/MS utilizou-se coluna Pursuit XRs C18 (150 x 2 mm d.i.; 5 μm), solução aquosa de hidróxido de amônio 0,01% (v/v) como fase móvel e detector triplo quadrupolo (TQ) operando no modo de monitoramento de reações selecionadas (SRM). A validação dos métodos foi realizada através de ensaios de recuperação, avaliando exatidão, precisão, linearidade, limites de detecção (LD) e de quantificação (LQ). As curvas analíticas para glifosato e AMPA obtidas para os níveis 25; 50; 100; 250 e 500 μg L-1 por CIC e LC-MS/MS apresentaram coeficiente de determinação (r2) >0,99 para ambos os compostos. Para as fortificações nos níveis de 25, 50, 250 e 500 μg L-1 os compostos apresentaram recuperações de 70 a 113%, com RSD <10% por CIC e recuperações foram de 79 a 105%, com RSD <14% por LC-MS/MS. Os limites de detecção do método para AMPA e glifosato foi 8 μg L-1 e o de quantificação foi de 25 μg L-1, em ambas as técnicas cromatográficas. Ambos os métodos apresentaram boa seletividade e sensibilidade. A determinação, através da injeção direta da amostra, de glifosato e AMPA utilizando cromatografia iônica capilar ou LC-MS/MS demonstrou ser uma ferramenta eficiente, simples e economicamente viável para análise, permitindo o monitoramento em níveis abaixo do valor máximo permitido em água potável.

[EN] The bidirectional DC-DC converters are being used more frequently in electric power systems. Bidirectional converters allows the incorporation of alternative and renewable energy sources at different voltage levels, by means of new power systems architectures now distributed not only centralized. The converters control is defined by function within the system, especially when there are large differences in voltage levels. It is desirable that the converter provide galvanic isolation, control current and / or voltage at one or both buses, and in some cases provide multi-port bidirectional conversion. One of the topologies with high power density is the single phase Dual Active Bridge (DAB). This thesis presents a study of a single phase DAB phase shifting controlled to meet the requirements of a bidirectional DC-DC converter for storage, parallel operation capability, high power density and fast dynamic response. The modularity of the DAB and the parallel operation arises from the conception of a control loop of Average Current Control (ACC), a double loop that controls the voltage and current of the high voltage side or controls the current and voltage at low voltage side. The dynamic response of a DAB to load steps are improved by means of a feedforward technique based on load current, an additional load-current feedforward control loop. An analytical study of the load-current feed-forward on DAB is presented and validated by means of both simulations and experimental results. The DAB topology exhibits a high input and output AC current ripple, especially at low voltage side. This thesis studies parallel connection by interleaving an average current control, based on two or more modules DAB operated synchronously but shifted in phase, in order to reduce the AC current and the capacitors size. The design has been validated by means of the implementation and testing on a 1 kW DAB converter at a switching frequency of 100 kHz. / [ES] Los convertidores DC-DC bidireccionales se están utilizando con mayor frecuencia en los sistemas de potencia eléctrica. Sus características permiten la incorporación de fuentes de energías alternativas y renovables de diferentes niveles de tensión, así como la propuesta de nuevas arquitecturas ahora distribuidas y no sólo centralizadas en los sistemas de potencia. El control de estos convertidores se realiza según su función dentro del sistema, en especial cuando hay grandes diferencias en los niveles de tensión. Es deseable que el convertidor ofrezca aislamiento galvánico, pueda tener funciones de control de corriente y/o de tensión en uno o en ambos puertos de conexión, y otros incluso tener más de dos puertos de intercambio de potencia eléctrica. Una de las topologías que ofrece la mejor densidad de potencia es la versión monofásica del puente activo dual DAB, de sus siglas del inglés "Dual Active Bridge". Se estudia en esta tesis doctoral un DAB monofásico con control por desplazamiento de fase para satisfacer los requerimientos de un convertidor DC-DC bidireccional con fines de almacenamiento, capacidad de operación en paralelo, alta densidad de potencia y rápida respuesta dinámica. La modularidad del DAB para operación en paralelo se plantea desde la concepción de un lazo de control de la corriente promedio ACC (Average Current Control), un lazo doble que controla la tensión y la corriente del lado de alta tensión ó controla la corriente y la tensión del lado de baja tensión. Para mejorar la dinámica del DAB se incluyó el análisis de una técnica de prealimentación basada en la inyección de la corriente de carga, load current feedforward. Esta mejora brinda una respuesta rápida ante variaciones de la carga. Un inconveniente que presenta el DAB por desplazamiento de fase es el alto rizado en las corrientes en los puertos de entrada y salida, especialmente en el lado de baja tensión. Se estudia para reducir este rizado el interleaving (entrelazado) con control de corriente media, basado en la conexión de dos o más módulos DAB en paralelo con disparos desfasados, logrando reducir el tamaño de los filtros. El diseño se ha validado mediante la construcción y experimentación en dos prototipos de potencia nominal de 1 kW con una frecuencia de conmutación de 100 kHz. / [CAT] Els convertidors DC/DC bidireccionals s'estan emprant amb major freqüència en els sistemes de potencia elèctrica. Les seues característiques permeten la incorporació de fonts d'energia alternatives i renovables de diferents nivells de tensió. També es permet la implementació en els sistemes de potència de les noves arquitectures distribuïdes i no només arquitectures centralitzades. El control d'aquests convertidors es realitza segons la seua funció dins del sistema, especialment quan hi ha grans diferències en els nivells de tensió. Es desitjable que el convertidor oferisca aïllament galvànic. A més pot tindre funcions de control de corrent i/o de tensió en un o ambdós ports de connexió. Altres convertidors poden tindre més de dos ports d'intercanvi de potència. Una de les topologies que proporciona la millor densitat de potència es la versió monofàsica del pont actiu dual DAB, de les seues sigles en anglès Dual Active Bridge. S'estudia en esta tesi doctoral un DAB monofàsic amb control per desplaçament de la fase per satisfer els requeriments d'un convertidor DC-DC bidireccional amb fins de emmagatzemament, capacitat d'operació en paral·lel, alta densitat de potència i ràpida resposta dinàmica. La modularitat del DAB per l'operació en paral·lel es planteja des de la concepció d'un llaç de control de la corrent mitjana ACC (Average Current Control), un llaç doble que controla la tensió i la corrent del costat d'alta tensió o controla la corrent i la tensió del costat de baixa tensió. Per millorar la dinàmica del DAB es va incloure l'anàlisi dúna tècnicade prealimentació basada en la injecció de la corrent de càrrega, LCFF (Load Current FeedForward). Esta millora brinda una resposta ràpida davant de variacions de la càrrega. Un inconvenient que presenta el DAB amb control per desplaçament de fase es l'alt arrissat de les corrents en els ports déntrada i eixida, especialment al costat de baixa tensió S'estudia per a reduir este arrissat l'entrellaçat (interleaving) de les corrents d'eixida amb la connexió dos o més modules DAB en paral·lel, aconseguint reduir la mida dels filtres. El disseny s'ha validat mitjançant la construcció i l'experimentació en dos prototips de potència nominal de 1 kW amb una freqüència de commutació de 100 kHz. / Guacaneme Moreno, JA. (2016). Control de puentes activos duales (DABs) en sistemas bidireccionales de alimentación con alta densidad de potencia [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61627 / TESIS