Silver nitrate staining, a rapid and efficient method, has proven to be excellent for nucleolar organizing region (NOR) studies in fish. Some fish appear to have only two NOR-bearing chromosomes in their karyo-type, whereas others probably have several. In the present study we analyzed the NORs of Leporinus friderici, a species that, on the basis of previous studies, has been considered as representative of species with NORs carried by a single chromosome pair. The analyses were performed by a combination of three methods, i.e. silver nitrate staining, staining with the GC-specific fluorochrome chromomycin A3, and in situ hybridization with digoxigenin-labeled probes. The results showed that, although more frequent and conspicuous in a single chromosome pair, the NORs of this species are present in multiple chromosomes. Intra- and inter-individual variations observed by the three methods strongly suggest the occurrence of post-zygotic modifications involving NORs. NOR identification in fish, almost exclusively performed by the silver nitrate method, is currently being re-evaluated by methods such as chromomycin A3 staining and in situ hybridization, which may provide important information leading to a better understanding of chromosome evolution in these animals.

This dissertation presents a new framework for the development and analysis of blind adaptive algorithms. An adaptive algorithm is said to be 'blind' if it does not require a known training sequence. The main focus is on application of these algorithms to adaptive antenna arrays in mobile radio communications. Adaptive antenna arrays can reduce the effects of cochannel interference, multipath fading, and background noise as compared to more conventional antenna systems. For these reasons, the use of adaptive antennas in wireless communication has received a great deal of attention in the literature. There are several reasons why the study of blind adaptive algorithms is important. First, it is common practice to switch to a blind mode once the training sequence has been processed in order to track a changing environment. Furthermore, the use of a blind algorithm can completely eliminate the need for a training sequence. This is desirable since the use of a training sequence reduces the number of bits available for transmitting information. The analysis framework introduced here is shown to include the well-known Constant Modulus Algorithm (CMA) and decision directed algorithm (DDA). New results on the behavior of the CMA and DDA are presented here, including analytic results on the convergence rate. Previous results have relied on Monte Carlo simulation. This framework is also used to propose a new class of blind adaptive algorithms that offer the potential for improved convergence rate. / Ph. D.

Submitted by admin tede (tede@pucgoias.edu.br) on 2016-09-13T13:52:57Z No. of bitstreams: 1 MARINA MACHADO SANTOS.pdf: 3084828 bytes, checksum: 7da6c5d67d268a88f71826629557e0c5 (MD5) / Made available in DSpace on 2016-09-13T13:52:58Z (GMT). No. of bitstreams: 1 MARINA MACHADO SANTOS.pdf: 3084828 bytes, checksum: 7da6c5d67d268a88f71826629557e0c5 (MD5) Previous issue date: 2016-05-16 / Chromosomal abnormalities cause specific and complex phenotypes due to imbalance in the normal dosage of genes located in a specific chromosomal segment. They account for 60% or even more of all the identifiable genetic syndromes. Williams-Beuren syndrome (WBS) is related to a group of multiple defects and intellectual disabilities, described independently by Williams et al. (1961) and Beuren et al. (1962). The WBS is a genetic disease characterized by a microdeletion of the 7q11.23 region, which delay the physical and intellectual development and it is associated with congenital cardiac abnormalities, facial dimorphism, mental retardation and occasionally infantile hypercalcemia.The existing phenotypic variation in this syndrome hinders clinical diagnosis.Through the development of new cytomolecular technologies and the increased number of studies regarding the clinical features of this syndrome, seeks a better understanding of the genotype-phenotype correlation in WBS. The present study reports some of these techniques used for the diagnosis of WBS, such as Karyotype, MLPA, PCR, with emphasis on FISH and CMA. Additionally, we described four patients who were referred to LaGene/SES and NPR/PUC by the public health service. Three of them had clinical suggestion of WBS and the fourth patient of ID. The confirmation was unsuccessful regarding the diagnostic through techniques of conventional cytogenetics for all of the patinets. FISH technique was useful in the diagnostic investigation of a patient while CMA was used to study the other 3 cases. Chromosomal microarray analysis detected long stretches of homozygosity of uncertain clinical significance at the Xq11.1q13.1 region and a microduplication at the 7q11.23 region, the latter is defined as a critical region of WBS. The study of genotype-phenotype correlation in WBS has been established for some genes detected by CMA. But other genes did not show a strong relation to the syndrome, thus requiring further investigation. / As anomalias cromossômicas causam fenótipos específicos e complexos resultantes de desequilíbrios na dose normal de genes localizados em um segmento cromossômico específico, sendo responsáveis por 60 % ou mais das síndromes genéticas identificáveis. A Síndrome de Williams-Beuren (SWB) caracteriza-se por anomalias múltiplas e deficiência intelectual, descrita independentemente por Williams et al. (1961) e por Beuren et al. (1962). A SWB consiste em uma doença genética causada pela microdeleção em 7q11.23, que ocasiona o atraso no desenvolvimento físico e intelectual associado com alterações cardíacas congênitas, dimorfismos faciais, retardo mental e ocasionalmente hipercalcemia infantil. A variação fenotípica existente nesta síndrome dificulta o seu diagnóstico clínico. Com o desenvolvimento de novas tecnologias citomoleculares e o aumento de estudos voltados para o conhecimento das características clínicas desta síndrome, busca-se explicar melhor a correlação genótipo-fenótipo na SWB. O presente estudo relata algumas técnicas utilizadas para o diagnóstico da SWB, como Cariótipo, MLPA e PCR, dando ênfase em FISH e CMA. Adicionalmente, são descritos quatro pacientes encaminhados ao LaGene/SES e NPR/PUC pelo serviço público de saúde, onde três destes pacientes apresentavam hipótese diagnóstica para a SWB e um paciente para a DI. Para os quatro pacientes não houve êxito no diagnóstico pela citogenética convencional. A técnica de FISH foi útil na elucidação diagnóstica para um paciente, enquanto que a CMA foi utilizada no estudo dos outros 3 casos. A análise cromossômica por microarranjo detectou longos trechos contínuos de homozigose de significado clínico incerto em Xq11.1q13.1 e um caso de microduplicação na região 7q11.23, que é definida como região crítica da SWB. O estudo da correlação genótipo-fenótipo na Síndrome de Williams-Beuren foi estabelecido para alguns dos genes detectados pelo CMA. Entretanto outros genes detectados não tiveram sua relação estabelecida, necessitando assim de estudos posteriores.

This thesis evaluates how the evolutionary algorithm CMA-ES (Covariance Matrix Adaption Evolution Strategy) can be used for optimizing the total initial margin for a network of banks trading bilateral OTC derivatives. The algorithm is a stochastic method for optimization of non-linear and, but not limited to, non-convex functions. The algorithm searches for an optimum by generating normally distributed samples and iteratively updating the mean and covariance matrix of the search distribution using the best candidate solutions in the sampled population. In this thesis, feasible solutions are represented by the null space obtained from the constraint of keeping all banks' market exposure unchanged throughout the optimization, and the generated samples for each iteration correspond to linear combinations of the base vectors spanning this null space. In particular, this thesis investigates how different representations of this null space affect the convergence speed of the algorithm. By applying the algorithm to problems of varying sizes, using several different null space representations coming from different matrix decomposition methods, it is found that as long as an orthonormal representation is used it does not matter which matrix decomposition method it comes from. This is found to be because, given any orthonormal null space representation, the algorithm will at start generate a rotationally invariant sample space in its search for the optimal solution, independent of the specific null space representation. If the representation is not orthogonal, the initial sample will in contrast be in the shape of an ellipsoid and thus biased in certain directions, which in general affects the performance negatively. A non-orthonormal representation can converge faster in specific optimization problems, if the direction of the solution is known in advance and the sample space is pointed towards that direction. However, the benefit of this aspect is limited in a realistic scenario and an orthonormal representation is recommended. Furthermore, as it is shown that different orthonormal representations perform equally, it is implied that other characteristics can be considered when deciding which matrix decomposition method to use; such as the importance of fast computation or desire for a sparse representation. / Denna avhandling utvärderar hur CMA-ES (Covariance Matrix Adaption Evolution Strategy) kan användas för att optimera en total "initial margin" för ett nätverk av banker som handlar bilaterala OTC derivat. Algoritmen är en stokastisk metod för optimering av icke-linjära och, men inte enbart, icke-konvexa funktioner. Algoritmen söker efter ett optimum genom att generera normalfördelade utfall och iterativt uppdatera medelvärdet och kovariansmatrisen för sök-fördelningen med hjälp av de bästa lösningarna i varje iteration. I detta arbete representeras tillåtna lösningar till problemet av nollrummet från bivillkoret att alla bankers marknadsexponering ska vara oförändrade genom optimeringen och de genererade utfallen består av slumpade linjärkombinationer av nollrummets basvektorer. I synnerhet undersöks hur olika representationer av nollrummet påverkar konvergenshastigheten för algoritmen. Algoritmen har applicerats med flera olika nollrumsrepresentationer, framtagna genom olika matrisfaktoriseringsmetoder, och det kan konstateras att så länge nollrummsrepresentationen är ortonormal är valet av faktoreringsmetod obetydlig. Detta då användande av orthornormala nollrumsrpresentationer i algoritmen leder till en initialt symmetrisk, rotationsmässigt invariant, sökning efter den optimala lösningen. Om representationen inte är ortogonal kommer det resulterande sökområdet i varje iteration att ha formen av en ellipsoid och sålunda viktas i vissa riktningar, vilket i allmänhet påverkar prestandan negativt. Emellertid kan en icke-ortonormal representation konvergera snabbare i specifika scenarier, givet att lösningens riktning är känd i förväg och sökområdet kan pekas mot den riktningen. Vidare, eftersom det har visats att olika ortonormala representationer konvergerar lika fort, innebär resultatet att andra egenskaper kan beaktas vid val av matrisfaktoriseringsmetod, såsom vikten av snabb beräkning eller önskan om en gles representation.

La quantité d’hydrocarbures récupérés peut être considérablement augmentée si un placement optimal des puits non conventionnels à forer, peut être trouvé. Pour cela, l’utilisation d’algorithmes d’optimisation, où la fonction objectif est évaluée en utilisant un simulateur de réservoir, est nécessaire. Par ailleurs, pour des réservoirs avec une géologie complexe avec des hétérogénéités élevées, le problème d’optimisation nécessite des algorithmes capables de faire face à la non-régularité de la fonction objectif. L’objectif de cette thèse est de développer une méthodologie efficace pour déterminer l’emplacement optimal des puits et leurs trajectoires, qui offre la valeur liquidative maximale en utilisant un nombre techniquement abordable de simulations de réservoir.Dans cette thèse, nous montrons une application réussie de l’algorithme “Covariance Matrix Adaptation - Evolution Strategy” (CMA-ES) qui est reconnu comme l’un des plus puissants optimiseurs sans-dérivés pour l’optimisation continue. Par ailleurs, afin de réduire le nombre de simulations de réservoir (évaluations de la fonction objectif), nous concevons deux nouveaux algorithmes. Premièrement, nous proposons une nouvelle variante de la méthode CMA-ES avec des méta-modèles, appelé le nouveau-local-méta-modèle CMA-ES (nlmm-CMA), améliorant la variante déjà existante de la méthode local-méta-modèle CMA-ES (lmm-CMA) sur la plupart des fonctions de benchmark, en particulier pour des tailles de population plus grande que celle par défaut. Ensuite, nous proposons d’exploiter la séparabilité partielle de la fonction objectif durant le processus d’optimisation afin de définir un nouvel algorithme appelé la partiellement séparable local-méta-modèle CMAES (p-sep lmm-CMA), conduisant à une réduction importante en nombre d’évaluations par rapport à la méthode CMA-ES standard.Dans cette thèse, nous appliquons également les algorithmes développés (nlmm-CMA et p-sep lmm-CMA) sur le problème de placement des puits pour montrer, à travers plusieurs exemples, une réduction significative du nombre de simulations de réservoir nécessaire pour trouver la configuration optimale des puits. Les approches proposées sont révélées prometteuses en considérant un budget restreint de simulations de réservoir, qui est le contexte imposé dans la pratique.Enfin, nous proposons une nouvelle approche pour gérer l’incertitude géologique pour le problème d’optimisation de placement des puits. L’approche proposée utilise seulement une réalisation, ainsi que le voisinage de chaque configuration, afin d’estimer sa fonction objectif au lieu d’utiliser multiples réalisations. L’approche est illustrée sur un cas de réservoir de benchmark, et se révèle être en mesure de capturer l’incertitude géologique en utilisant un nombre réduit de simulations de réservoir. / The amount of hydrocarbon recovered can be considerably increased by finding optimal placement of non-conventional wells. For that purpose, the use of optimization algorithms, where the objective function is evaluated using a reservoir simulator, is needed. Furthermore, for complex reservoir geologies with high heterogeneities, the optimization problem requires algorithms able to cope with the non-regularity of the objective function. The goal of this thesis was to develop an efficient methodology for determining optimal well locations and trajectories, that offers the maximum asset value using a technically feasible number of reservoir simulations.In this thesis, we show a successful application of the Covariance Matrix Adaptation - Evolution Strategy (CMA-ES) which is recognized as one of the most powerful derivative-free optimizers for continuous optimization. Furthermore, in order to reduce the number of reservoir simulations (objective function evaluations), we design two new algorithms. First, we propose a new variant of CMA-ES with meta-models, called the newlocal-meta-model CMA-ES (nlmm-CMA), improving over the already existing variant of the local-meta-model CMA-ES (lmm-CMA) on most benchmark functions, in particular for population sizes larger than the default one. Then, we propose to exploit the partial separability of the objective function in the optimization process to define a new algorithm called the partially separable local-meta-model CMA-ES (p-sep lmm-CMA), leading to an important speedup compared to the standard CMA-ES.In this thesis, we apply also the developed algorithms (nlmm-CMA and p-sep lmm-CMA) on the well placement problem to show, through several examples, a significant reduction of the number of reservoir simulations needed to find optimal well configurations. The proposed approaches are shown to be promising when considering a restricted budget of reservoir simulations, which is the imposed context in practice.Finally, we propose a new approach to handle geological uncertainty for the well placement optimization problem. The proposed approach uses only one realization together with the neighborhood of each well configuration in order to estimate its objective function instead of using multiple realizations. The approach is illustrated on a synthetic benchmark reservoir case, and is shown to be able to capture the geological uncertainty using a reduced number of reservoir simulations.

Populärvetenskaplig sammanfattning Optimering av dammbindning på Hornsgatan med NORTRIP modellen Massan av luftburna partiklar med en diameter mindre än 10 µm (PM10) är en av de tuffaste miljökvalitetsnormerna att uppnå i Sverige. PM10 kommer från flera olika källor, både naturliga som havssalt och sand, samt antropogena som vägslitage, däckslitage, bromsslitage och avgaser. En stor uppkomstkälla till PM10 i luften slitage på grund av dubbdäcksanvändning. Uppvirvlingen är som störst i mars och april efter att snön smält, temperaturen stigit och vägbanan torkat upp. För att minska PM10 halten i luften kan en dammbindande saltlösning med lägre fryspunkt än vatten läggas ut på vägbanan. I Stockholm används saltlösningen CMA (kalciummagnesiumnitrat). Det är en typ av salt med liten påverkan på den urbana miljön. Vintersäsongen 2016–2017 lades CMA ut tre gånger i veckan på några utvalda gator i Stockholm mellan november och maj. En av dessa gator är Hornsgatan, som har undersökts i denna rapport. CMA är dyrt och resurskrävande att lägga ut. För att optimera utläggningen av CMA i Stockholm har spridningsmodellen NORTRIP (non-exhaust road traffic induced particle emissions) använts. Modellen använder meteorologiska data, trafikdata och data rörande saltning, sandning och städning för att räkna ut halten PM10 som spridits till luften. Den här modellen har använts för att testa några olika dammbindande scenarion på Hornsgatan i vilka CMA har lagts ut. Det har också testats, i NORTRIP, om PM10 halten i luften skulle minska genom utläggning av vatten på vägen. Vatten lades endast ut i modellen efter 15 mars med antagandet att temperaturen inte skulle sjunka under 0 °C efter datumet ifråga. De olika scenariona var utformade för att se om det var möjligt att minimera användandet av CMA men ändå hålla nere PM10 halten i luften. Alla scenarion jämfördes med scenariot där varken CMA eller vatten lades ut för att jämföra om PM10 i luften minskade. Ett resultat visade att det var bättre att lägga ut CMA varje dag under dammiga perioder än att sikta in sig på bara de dammigaste dagarna. PM10 i luften 2016 minskade med 4,7% när de 45 dammigaste dagarna behandlades med CMA. Det kan jämföras med en minskning på 6,5% när CMA applicerades under dammiga perioder under samma år. En annan slutsats var att det ger större effekt att lägga ut CMA i mars och april än mellan november och mars. PM10 i luften 2016 minskade med 2,1% om man började lägga ut CMA 1 november som planerat, och med 1,7% om utläggningen började i slutet av februari, när den dammiga säsongen börjar. Det resulterar i att endast en liten minskning av PM10 halten uppnåddes genom att börja behandla vägbanan med CMA den 1 november istället för i slutet av februari. Att börja lägga ut CMA i slutet av februari istället för 1 november skulle minska kostnaderna betydligt för staden. Resultaten visade även att ett tunt lager vatten (0,3 mm) utlagt på vägbanan mellan ordinarie dagar för dammbindning hade en betydande effekt på PM10 halten i luften. Vid vattenutläggning mellan dagarna för CMA utläggning efter 15 mars 2016 minskar PM10 i luften under 2016 med 1,4% utöver vad den skulle minskat med om inget vatten lagts ut. Den här rapporten visar att det är möjligt att optimera utläggningen av CMA på Hornsgatan. / Abstract Optimization of dust-binding on Hornsgatan with the NORTRIP model The mass of airborne particles with a diameter smaller than 10 µm (PM10) is one of the most difficult environmental quality standards addressed in Sweden. PM10 particles originates from a variety of sources; natural, like sea salt and sand, and human made like road wear, tire wear, brake wear and exhaust. A significant source of PM10 in the air is the usage of studded tires. The suspension typically occurs in March and April when the snow layer melts, temperature rises and the streets dry. A dry street is crucial for the road dust to suspend into the air. A way to prevent road dust to suspend in to the air is spraying the road with a salt solution that does not freeze at temperatures below 0 °C. In Stockholm a dust-binding substance called CMA (Calcium Magnesium Acetate) is used. It is a of salt with minimal negative side effects on the urban environment. CMA was applied on some specific streets in Stockholm three times a week between November and May winter season 2016–2017. One of the streets that gets treated with CMA is Hornsgatan which is the topic of this paper. Dust-binding substances are expensive and time consuming to apply to the streets. To optimize the appliance of CMA in Stockholm a non-exhaust road traffic induced particle emissions (NORTRIP) model has been used. The model uses meteorological data, traffic data combined with data on salting, sanding and cleaning to calculate PM10 suspension to the air. This model has been used to test different dust-binding scenarios on Hornsgatan in which CMA was applied. It has also been tested, in NORTRIP, if spraying the road with water could have a reductive effect on PM10 in the air. Water was only added to the model after the 15th of March because it was assumed the temperature would not sink below 0 °C after this date. The different scenarios were formed to see if it was possible to minimize the usage of CMA and still keep the PM10 level low. All scenarios were compared with the scenario of not applying any CMA or water to see how much PM10 in the air was reduced. One result showed that it is better to apply CMA every day during dusty periods rather than just manage to target the dustiest days alone. PM10 in the air 2016 was reduced by 4.7% when the 45 dustiest days were treated with CMA. This could be compared to a 6.5% reduction when CMA was applied during dusty periods. Another conclusion made was that applying CMA in March and April has a greater effect then applying CMA in November, December, January and February. PM10 in the air 2016 was reduced by 2.1% if the CMA treatment started on the 1st of November as planned, and by 1.7% if the treatment started in the end of February when the dusty season starts. That means there is only a small decrease of PM10 if the appliance of CMA starts in the end of February rather than the 1st of November. Reducing the days of CMA treatment would reduce the cost significantly for the city. It was also shown that a thin layer of water (0.3 mm) applied to the street between ordinary dust-binding days has a significant effect on PM10 in the air. Adding water to the street in between days of dust-binding after the 15th of March 2016 reduced suspended PM10 2016 in the air by 1.5% beyond what it would have been reduced without the water. This paper shows that it is possible to optimize the appliance of CMA.

Un alliage métallique complexe (CMA) est un composé intermétallique dont la maille élémentaire est constituée d’un nombre important d’atomes formant bien souvent des aggrégats de haute symmétrie. De la complexité de ces composés peuvent découler des propriétés physico-chimiques intéressantes pour divers domaines d’application. Le système binaire aluminium-iridium est un système qui présente de nombreux composés intermétalliques dont la moitié sont des CMA. Malgré l’étude approfondie dont ce système a fait l’objet dans la littérature, certaines incertitudes demeuraient irrésolues, nous amenant ainsi à réexaminer le diagramme de phase Al-Ir. Nous avons également exploré les systèmes ternaires dits "push-pull" Al-Au-Ir et Al-Ag-Ir, propices à la formation de phases CMA selon certains auteurs. Au total, une centaine d’échantillons ont été préparés par fusion à l’arc puis analysés par diverses techniques de caractérisations: diffraction des rayons X (XRD), microscopie électronique à balayage (SEM), analyse dispersive en énergie (EDS) et analyse thermique différentielle (DTA). Quatre nouveaux composés intermétalliques ont ainsi été identifiés: Al2.4Ir, Al72Au2.5Ir29.5, Al3AuIr et Al11SiIr6, ce dernier étant issu d’une manipulation accidentelle. La structure cristallographique de chacun de ces composés a été résolue, révélant Al2.4Ir et Al72Au2.5Ir29.5 comme étant des CMA possédant une centaine d’atomes dans la maille. Des calculs basés sur la théorie de la fonctionnelle de la densité (DFT) sont venus apporter des précisions concernant la stabilité des composés Al3AuIr et Al11SiIr6. Pour le système Al-Ir, une variante structurale de deux CMA déjà connus de la littérature a également pu être mise en évidence. Les structures cristallographiques de la variante de Al2.75Ir et de celle de Al28Ir9 ont ainsi été approchées, présentant 240 et 444 atomes dans leur maille respective. Les propriétés de surface comptent parmi les aspects les plus intéressants des CMA, par exemple pour la catalyse hétérogène. En l’absence de monocristaux de taille macroscopique, nous avons étudié la possibilité de former des composés de surface par dépôt de Ir sur une surface Al(100) suivi de recuits. Des caractérisations par diffraction d’électrons lents (LEED), spectroscopie de photoélectrons excités par rayons X (XPS) et microscopie à effet tunnel (STM) supportés par ces calculs ab initio ont révélé qu’à partir de 320°C, le composé Al9Ir2 se formait en surface mais également dans une partie du volume du substrat / A complex metallic alloy (CMA) is an intermetallic compound whose unit cell contains a large number of atoms oftenly forming highly-symmetric clusters. From the complexity of these compounds can arise physical and chemical properties interesting for various fields of application. The aluminium-iridium binary system exhibits numerous intermetallic compounds of which half of them are actually CMAs. Despite this system being extensively studied in the literature, some uncertainies remained unsolved, leading us to reinvestigate the Al-Ir phase diagram. In addition, the "push-pull" systems Al-Au-Ir and Al-Ag-Ir, favorable for the formation of CMA according to the literature, have been explored. Thus, near a hundred of samples have been prepared by arc-melting before being analyzed with different characterizations techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and differential thermal analysis (DTA). From this study, 4 new intermetallic compounds could be identified: Al2.4Ir, Al72Au2.5Ir29.5, Al3AuIr and Al11SiIr6, the latter being the result of a fortuitous manipulation. The crystallographic structure of each of these compounds has been solved, revealing Al2.4Ir and Al72Au2.5Ir29.5 to be two CMAs with around one hundred of atoms in their unit cell. Calculations based on the density functional theory (DFT) brought further details about the stability of the two other Al3AuIr and Al11SiIr6 compounds. In the Al-Ir binary system, a structural variant of two well-known CMAs has been also unveiled. The crystallographic structures of the Al2.75Ir and Al28Ir9 variant have been approached, revealing 240 and 444 atoms in their respective unit cell. The CMAs oftently exhibit interesting surface properties. In order to study the Al-Ir compound surfaces, iridium adsorption on Al(100) surface followed by annealing has been investigated. The characterizations by lowenergy electrons diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning tunneling miscoscopy (STM) supported by ab initio calculations revealed that, from 320 C, the Al9Ir2 compound is formed at the surface but also in the substrate bulk

L'invention de l'antenne fût à la base de la création des communications sans fil à l'orée du XXe siècle. A l'origine des objets métalliques destinés à transmettre et recevoir des ondes électromagnétiques, les antennes n'ont cessé de se complexifier pour satisfaire l'impressionnant développement des communications sans fil. C'est dans ce contexte qu'est né le concept d'antenne « wearable » il y a moins de deux décennies ouvrant un nouveau champ de recherche sur les antennes souples. C'est dans ce cadre que ce travail de thèse se consacre à la conception d’antennes souples en bande UHF.Une première étude a permis de concevoir une antenne Vivaldi antipodale [150 - 900 MHz] souple pour la Section Technique de l'Armée de Terre. Six de ces antennes sont destinées à être placées sous un ballon gonflé à l'hélium pour réceptionner des signaux RF.Une seconde étude est effectuée en collaboration avec la société Syrlinks et le CNES. L'objectif du projet est de concevoir des antennes souples pour le suivi de personnes avec le système ARGOS (401 et 466 MHz). La solution retenue est une PIFA planaire de largeur inférieure à lambda/3. Elle a l'avantage d'être fine et légère. Le matériau souple employé est un caoutchouc silicone sélectionné parmi plusieurs matériaux souples grâce à des caractérisations diélectriques. Cependant, le problème de cette antenne est qu'elle possède un rayonnement quasi-omnidirectionnel. Etant donné qu'il n'était pas envisageable d'utiliser un plan réflecteur métallique pour des raisons de dimensions, il a été décidé de concevoir un conducteur magnétique artificiel (CMA) souple. Toutefois, la conception de CMA dans le bas de la bande UHF se heurte à des difficultés de miniaturisation. Pour contourner ce problème, il a été développé deux concepts de CMA à cellules unitaires de faibles dimensions devant la longueur d'onde. La première solution utilise des capacités interdigitées et la seconde une structure double couche. Pour ces deux concepts, un modèle circuit est proposé et validé par des mesures expérimentales. Les mesures de l'association CMA - antenne montrent une bande passante suffisante pour des applications ARGOS et un rayonnement majoritairement dirigée dans la direction opposé à celle du CMA. / The invention of antennas was the base of wireless communications appearance at the dawn of the twentieth century. Originally metal objects for transmitting and receiving electromagnetic waves, antennas have steadily become more complex to meet the impressive development of wireless communications. It is in this context that the concept of wearable antennas was born less than two decades ago opening a new field of research namely flexible antennas. It is in this framework that this thesis is dedicated to the design of flexible antennas for UHF band.A first study enabled the design of a flexible antipodal Vivaldi antenna [150-900 MHz] for Technical Section of the Army. Six of these antennas are intended to be placed under a balloon inflated with helium for receiving RF signals.A second study was conducted in collaboration with the company Syrlinks and CNES. The objective of the project is to design flexible antennas for tracking people with ARGOS system (401 and 466 MHz). The selected solution is a planar PIFA which width is smaller than lambda/3. This antenna has the advantage of being thin and light. The flexible material used is a silicone rubber and it was selected among several others due to some dielectric characterizations. However, the drawback of this antenna is that it has a quasi-omnidirectional radiation pattern. Since it was not possible to use a reflector metal plane due to size constraints, it was decided to design a flexible artificial magnetic conductor (AMC). However, the design of AMCs in the lower UHF band is challenged with the miniaturization difficulties. Two concepts of small size (compared to the wavelength) AMCs unit cells were developed to work around this problem. The first solution uses interdigitated capacitors and the second a double layer structure. For these two concepts, a circuit model is proposed and validated by experimental measurements. The measurement of the AMC associated antenna demonstrates a bandwidth sufficient for ARGOS applications and a radiation pattern mostly directed in the direction opposite to that of the AMC.

The rapid electrification of vehicles has neccessitated advancements in battery technology, impacting various components within the car battery pack. This project focuses on the development of thermal barriers, which serve as crucial components that prevent potential fires from thermal runaway incidents in the battery pack from reaching the vehicle's interior compartment. Currently, thermal barriers are predominantly composed of mica. The objective of this project is to identify a more sustainable alternative material to mica that possesses similar properties while considering economic, social, and environmental factors.  Following the product development process, a comprehensive background study and benchmark analysis were conducted. Subsequently, the specific requirements for the new material were defined, and potential suppliers providing alternative materials were identified. Torch tests and dielectric strength tests were performed to assess thermal conductivity, fire resistance, and dielectric properties, which were deemed critical attributes. The test results unveiled a novel material comprised of a combination of two distinct materials from different suppliers. One material was a composite consisting of glass fiber and carbon, exhibiting exceptional thermal properties. The other material was an electrical-grade paper boasting excellent electrical properties. When combined, these materials formed a composite that paralleled the properties of mica. The composite material had a total thickness of 2 mm, slightly thicker than the current implementation of mica. To explore the feasibility of a thinner alternative, an estimation was conducted, suggesting that a thinner sheet of the composite material could be possible. In conclusion, this study demonstrates the feasibility of replacing mica with an alternative material. Further testing and investigation are required to determine the optimal implementation and minimum thickness of the new material. However, based on the successful test results and similarity in properties, it can be affirmed that the new material has the potential to replace mica as a sustainable thermal barrier in the battery pack. / Denna avhandling fokuserar på utvecklingen av hållbara termiska barriärer som ersättning för mica i batteripacken i elektriska bilar, vilket har blivit nödvändigt på grund av den snabba elektrifieringen av fordon. Syftet med studien är att identifiera ett mer hållbart alternativ till mica och samtidigt ta hänsyn till ekonomiska, sociala och miljömässiga faktorer. Genom att följa produktutvecklingsprocessen har en omfattande bakgrundsstudie och benchmark-analys genomförts. Därefter definierades specifika krav för det nya materialet, och potentiella leverantörer av alternativa material identifierades. Väsentliga attribut som termisk ledningsförmåga, brandsäkerhet och elektriska egenskaper utvärderades genom att utföra flam-tester och tester för den elektriska ledningsförmågan. Resultaten av testerna resulterade i ett innovativt material bestående av en kombination av två olika material från olika leverantörer. En komposit av glasfiber och kol visade exceptionella termiska egenskaper, medan ett elektriskt kvalitetspapper uppvisade utmärkta elektriska egenskaper. När dessa material kombinerades bildade de en komposit som liknade micas egenskaper. Det komposita materialet hade en total tjocklek på 2 mm, något tjockare än mica. Genom en uppskattning undersöktes möjligheten att använda en tunnare variant av det komposita materialet. Sammanfattningsvis visar denna studie att det är genomförbart att ersätta mica med det föreslagna alternativa materialet. Vidare tester och undersökningar krävs för att optimera implementeringen och fastställa den minsta möjliga tjockleken på det nya materialet. Baserat på de positiva testresultaten och likheten i egenskaper kan det konstateras att det föreslagna materialet har potential att vara en hållbar termisk barriär i batteripaket.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / This paper will present the results of experiments to characterize the performance of a blind, adaptive constant modulus algorithm (CMA) equalizer in simulated telemetry multipath environments. The variables included modulation method, bit rate, received signal-to-noise ratio, delay of the indirect path relative to the direct path, amplitude of the indirect path relative to the direct path, and fade rate. The main measured parameter was bit error probability (BEP). The tests showed that the equalizer usually improved the data quality in the presence of multipath.