Dissertations / Theses on the topic 'Q-V'

Thesis in the first part deals with the theoretical background for the analysis of the educational system. It describes the different phases of the educational system and possible approaches to training staff. The next part is a practical analysis of the education system of sales representatives at Top Moravia Q. This study focuses on introductory training for sales representatives and subsequent training, a personal training manager, working meeting and seminars. Through qualitative and quantitative research investigated the views of program participants on its meaning, effectiveness and contribution. The final part of the evaluation of the findings made and formulated recommendations for improving the program and the educational system as a whole. Also evaluated the overall company's approach to educational activities.

Tato práce se zabývá synchronním motorem s permanentními magnety na rotoru (PMSM), jeho modelováním a návrhu regulační struktury. V práci jsou uvedeny způsoby a výhody použití permanentních magnetů v elektrických motorech. Dále se práce zabývá transformací třífázové soustavy do dq0. Pomocí Parkovy transformace jsou v práci odvozeny rovnice stroje v dq0 souřadnicovém systému a vytvořeny náhradní schémata stroje v dq osách. Rovnice i schémata zahrnují jak ztráty v mědi, tak ztráty v železe. Náhradní schémata jsou popsány elektrickými a mechanickými rovnicemi a následně překresleny do grafické podoby v programu Matlab Simulink. Vytvořeny jsou dva modely PMSM, jeden s uvažováním ztrát v železe a druhý bez těchto ztrát. Pro oba dva modely je zde popsán postup návrhu regulátorů proudu a otáček. Pro model, u kterého jsou uvažovány ztráty v železe je navíc použito více druhů řídicích strategií a tyto strategie jsou mezi sebou navzájem porovnány.

Submitted by repositorio repositorio (repositorio@unifei.edu.br) on 2017-09-04T14:31:37Z No. of bitstreams: 1 dissertacao_pinto2_2013.pdf: 2197284 bytes, checksum: 5f0d0fad83440e2d168ef52233d44118 (MD5)
Made available in DSpace on 2017-09-04T14:31:37Z (GMT). No. of bitstreams: 1 dissertacao_pinto2_2013.pdf: 2197284 bytes, checksum: 5f0d0fad83440e2d168ef52233d44118 (MD5) Previous issue date: 2013-04
A necessidade de manter o sistema em operação com níveis cada vez maiores de carga, torna-se evidente que o estudo da capacidade de carregamento do sistema deva ser mais detalhado. Inúmeros estudos demostram a importância de se determinar o ponto de colapso e a necessidade de identificar as barras críticas, susceptíveis a levar o sistema completo a esse colapso. O controle de tensão nessas barras pode não ser suficiente já que a capacidade de transmissão de potência entre barras deve ser considerada e que, no caso de sistemas já sobrecarregados essa capacidade se apresenta bastante reduzida. Como motivação deste trabalho, está a necessidade de melhorar a análise de sistemas existentes. Essa melhora se caracteriza por uma verificação do estado geral de carregamento do sistema e sua capacidade de transmissão de potência por área analisada, utilizando-se de métodos já consagrados. Para determinação da margem de carga do sistema durante o aumento de seu carregamento foi utilizada a curva P-V, e para determinação da barra crítica foi utilizado o método do vetor tangente. Como complemento da avaliação do estado geral da capacidade de transmissão, foram utilizadas outras duas propostas: o uso da curva Q-V e o estudo da Função Energia.

Ce mémoire est consacré au développement de technologies de filtrage novatrices qui apportent un gain en performance permettant de répondre aux besoins de filtrage pour télécommunications spatiales à moyen et long termes. Il s’inscrit dans le projet ANR ATOMIQ coordonné par Thales Alenia Space ayant comme partenaires le laboratoire SPCTS et la société 3D CERAM. Le premier chapitre est constitué d’une étude bibliographique sur les filtres en bande Q et V ainsi que les technologies de fabrication 3D. Le deuxième chapitre est consacré à l’élaboration d’une nouvelle formulation d’alumine très pure à faible pertes et stable en température. Le troisième chapitre présente une conception de filtres hyperfréquences en bande Q et V à base de cavités résonantes diélectriques. Le quatrième chapitre concerne la fabrication des filtres par usinage en cru ainsi que la présentation des différents démonstrateurs fabriqués par stéréolithographie et moulage basse pression. Il présente aussi des solutions de correction post-fabrication par tir laser. Ce travail est original par l’utilisation de la stéréolithographie céramique 3D ainsi que du moulage basse pression pour fabriquer des filtres hyperfréquences de petites tailles en bande Q et V
This thesis focus on the development of innovative filtering technologies that enhance the performance to meet the filtering requirements for spacial communications. It is part of the ANR project ATOMIQ coordinated by Thales Alenia Space with partners (SPCTS 3D CERAM). The first chapter consists of a literature review on the Q and V band filters as well as 3D manufacturing technologies. The second chapter is devoted to the development of a new formulation of highly pure, low losses and temperature stable alumina. The third chapter presents a microwave filter design in Q and V band based on a dielectric resonant cavity. The fourth chapter is about the manufacturing of filters and presentation of various demonstrators manufactured by stereolithography and low pressure molding. It also provides a post-production correction solutions based on laser shoots. This work is original because, to the best of our knowledge, 3D ceramic stereolithography and the low pressure molding have not been used to produce small sizes Q and V band microwave filters

Les travaux présentés dans cette thèse concernent l’étude et la fabrication de composants passifs hyperfréquence possédant un facteur de qualité important sur les bandes Q et V. Pour cela, nous nous sommes orientés vers la fabrication de composants volumiques à air. Des lignes coaxiales à section rectangulaire à air ainsi que des filtres à cavité métalliques à air ont été réalisés. Aussi, ces travaux consistent à définir une méthode de fabrication permettant d’obtenir les composants cités précédemment. Plusieurs techniques de micro-fabrication additives ont ainsi été établies afin de répondre à la problématique
This work concerns the study and the fabrication of passive RF components with a high quality factor on Q/V bands. The components were fabricated with an air-filled 3D architecture. Air-filled rectangular micro-coaxial lines and air filled cavity filters were demonstrated. Also, micro-additive fabrication processes were demonstrated for the realization of the 3D air-filled components

Considering the requirements of the commercial and military applications on amplitude and phase linearity, it is necessary to reduce nonlinearity of the amplifiers. There are several linearization techniques that are used to reduce nonlinearity effects. Feedforward linearization technique is known as one of the best linearization methods due to its superior linearization performance and broadband operation. Vector modulators which allows amplitude and phase modulation simultaneously, is the most important component of a feedforward system. In this thesis, first of all a broadband V/UHF vector modulator designed and implemented. Then a feedforward system is investigated and implemented using the designed vector modulator for V/UHF band.

A modification of the modulated elemental reactants synthetic technique was developed and used to synthesize several new layered compounds. Several TSe2, [(SnSe)1+y]m(TSe2)n, [(SnSe)1+y]m(TSe2)n[(SnSe)1+y]p(T'Se2)q, and (SnSe)1+y(V1-xTaxSe2) layered compounds were synthesized by the new modulated elemental reactant (MER) technique with T = V, Ta, and Ti. The MER approach is a low-temperature synthesis that allows the kinetic trapping of metastable compounds, allowing a designed synthesis with control over the value of m, n, p, and q. These layered compounds were structurally characterized by X-ray diffraction and transmission electron microscopy studies. Each integer increase of m, n, p, and q resulted in a linear increase in thickness, representing the single structural units of SnSe (a Sn/Se atomic bilayer) and TSe2 (an X-T-X trilayer sandwich). All of the compounds contained preferentially oriented layering, with the layer's (00l) plane parallel to the substrate surface. From Bragg-Brentano and in-plane X-ray diffraction studies, the layers are found to be regularly spaced along c with abrupt interfaces and contain crystallinity in their ab-plane. Many of these layered compounds were found to exhibit turbostratic disorder, a random rotational disorder that is usually present in materials made by the MER technique. The presence of turbostratic disorder was found to be dependent on the polytypes that exist in the bulk form of the TSe2 constituent. The electrical properties of the layered compounds were studied by means of temperature-dependent resistivity and Hall measurements. Interesting electrical properties were found as a result of the turbostratic disorder, including a charge density wave transition found in the [(SnSe)1.15]m(VSe2) ferecrystal. The onset temperature of the CDW transition was found to be a sensitive function of the layering sequence, increasing with higher m values. The CDW transition was attributed to the VSe2 constituent and was found in all the composite crystals that contained VSe2. It was found that the [(SnSe)1+y]m(VSe2)n and [(SnSe)1+y]m(TaSe2)n intergrowths could be combined into an ABCB layered [(SnSe)1+y]m(VSe2)n[(SnSe)1+y]p(TaSe2)q intergrowth, with chemical separation of the VSe2 and TaSe2 constituents. This dissertation includes previously published and unpublished co-authored material.

Thesis (MScMedSC (Medical Imaging and Clinical Oncology. Nuclear Medicine))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Single photon emission computed tomography (SPECT) with a superior contrast resolution has been shown to be more sensitive and specific with a lower nondiagnostic rate than planar imaging in many nuclear medicine studies but it is still not being routinely implemented in V/Q studies at many centres including Tygerberg Hospital. There are many studies on V/Q SPECT using Technegas as a ventilation agent but very limited studies available on 81m Kr gas. Aim: To clinically compare conventional planar and SPECT V/Q imaging using 81mKr gas in the diagnosis of pulmonary embolism, with CTPA as the gold standard. Patients and Methods: All patients referred with clinical suspicion of pulmonary embolism were assessed. The inclusion criteria were normal chest radiograph, normal renal function and no contrast allergy. Exclusion criteria were age below 18 years old, pregnancy, abnormal chest radiograph, abnormal serum creatinine/urea levels and unstable patients. A Well’s score was assigned to each enrolled patient. Perfusion scintigraphy was performed after intravenous injection 125 MBq of 99mTc MAA. Ventilation scintigraphy was performed with 81mKr gas. On a dual head camera, SPECT was done before planar acquisition, while perfusion was done before ventilation imaging in the same position. Planar V/Q images consisted of 6 standard views. All V/Q SPECT images were reconstructed using ordered-subset expectation-maximization (OSEM) algorithm and a post-reconstruction 3D Butterworth filters were applied. V/Q Planar and V/Q SPECT images were later evaluated and reviewed separately and reported based on recent EANM guidelines blinded to the CTPA results. All patients underwent multi-slice CTPA examinations on a 40-detector row scanner. The images were later assessed and reported blinded to the V/Q results. Statistical analysis was done using the Fisher exact test for comparison of categorical variables and the one-way ANOVA for continuous variables (p<0.05 was significant). Results: A total of 104 consecutive patients were referred with clinical suspicion of pulmonary embolism. Seventy-nine patients were excluded from this study mostly due to abnormal serum creatinine/urea levels. Only 25 patients were included in this study, with a mean age of 48 ± 19 years, and 64% being females. When compared to CTPA as gold standard, the prevalence of PE was 16% [5% – 37% at 95% CI], sensitivity 75% [21% – 99% at 95% CI], specificity 90% [68% – 98% at 95% CI], positive predictive value 60% [17% – 93% at 95% CI], negative predictive value 95% [73% – 100% at 95% CI] and diagnostic accuracy 88% [69% – 97%at 95% CI] for both V/Q Planar and SPECT. V/Q Planar showed a lower reader confidence i.e. could only clearly resolve 72% of cases compared to V/Q SPECT, which could precisely interpret all cases, showed more and better delineated mismatch vs match and segmental vs non-segmental defects. All patients who were scored as PE unlikely on Wells’ score (4) had PE ruled out on CTPA (p=0.04581) as well as 89% of patients on V/Q SPECT and V/Q Planar. Conclusion: Based on this study, V/Q Planar and V/Q SPECT have a similar diagnostic performance in patients with a normal or near normal chest X-rays.
AFRIKAANSE OPSOMMING: Enkelfoton emissie rekenaartomografie (EFERT) met beter kontrasresolusie is bewys om meer sensitief en spesifiek met ‘n laer nie-diagnostiese opbrengs as planare beelding in verskeie kerngeneeskunde ondersoeke te wees. In Tygerberg Hospitaal, soos in verskeie ander sentra, word dit egter steeds nie roetineweg vir ventilasie-perfusiestudies (V/Q) geïmplementeer nie. Daar is verskeie EFERT V/Q studies met Technegas as ventilasie agens, maar beperkte studies met 81m Kr gas beskikbaar. Doel: Om konvensionele planare en EFERT V/Q beelding vir die diagnose van pulmonale embolisme met mekaar te vergelyk, met rekenaartomografie pulmonale angiografie (RTPA) as goue standaard. Pasiënte en Metodes: Alle pasiënte wat met ‘n kliniese vermoede van pulmonale embolisme verwys is, is geevalueer. Die insluitingskriteria was ’n normale borskas Xstraal, normale nierfunksie en geen kontrasallergie nie. Uitsluitingskriteria was pasiënte jonger as 18 jaar, swanger pasiënte, abnormale borskas X-straal, abnormale serum kreatinien / ureumvlakke en onstabiele pasiënte. ’n Wells telling is vir elke pasiënt wat in die studie ingesluit is, bepaal. Perfusiebeelding is uitgevoer na die intraveneuse toediening van 125 MBq 99mTc MAA. Ventilasiestudies is gedoen met 81mKr gas. Die V/Q EFERT studies is voor die planare beelding met ’n dubbelkop gammakamera uitgevoer. Perfusiebeelding is voor die ventilasie in dieselfde posisie verkry. V/Q planare beelding het bestaan uit 6 standaard beelde. Alle V/Q EFERT is met “ordered-subset expectationmaximization” (OSEM) algoritmes verwerk, en post-rekonstruksie 3D Butterworth filters is toegepas. V/Q planare en V/Q EFERT beelding is later afsonderlik en sonder RTPA inligting volgens onlangse EANM riglyne evalueer en gerapporteer. ‘n Veelsnit RTPA met ‘n 40 snit skandeerder is op alle pasiënte uitgevoer. Die beelde is later beoordeel en gerapporteer sonder inagneming van die V/Q beeldingsresultate Statistiese verwerking is gedoen met die Fisher presisietoets vir vergelyking van kategoriese veranderlikes en die eenrigting ANOVA vir kontinue veranderlikes (p<0.05 is statisties betekenisvol). Resultate: ‘n Totaal van 104 opeenvolgende pasiënte met ‘n kliniese vermoede van pulmonale embolisme is verwys. Nege-en-sewentig pasiënte is uitgesluit, in die meeste gevalle as gevolg van abnormale serum kreatinienvlakke. Slegs 25 pasiënte is ingesluit, met ’n gemiddelde ouderdom van 48 ± 19 jaar, en 64% vroue. In vergelyking met RTPA as goudstandaard, was die prevalensie van PE 16% [5% – 37% met 95% VI], sensitiwiteit 75% [21% – 99% met 95% VI], spesifisiteit 90% [68% – 98% met 95% VI], positiewe voorspellingswaarde 60% [17% – 93% met 95% VI], negatiewe voorspellingswaarde 95% [73% – 100% met 95% VI] en diagnostiese akkuraatheid van 88% [69% – 97% met 95% VI] vir beide planare en EFERT V/Q beelde. V/Q planare beelde het ‘n laer lesersvertroue getoon, nl. dat slegs 72% van gevalle opgelos kon word relatief tot V/Q EFERT beelde, wat in alle gevalle presies geïnterpreteer kon word, met meer en beter omskrewe nie-ooreenstemmende teenoor ooreenstemmende en segmentele teenoor nie-segmentele defekte. In alle pasiënte met ‘n Wells puntetelling van 4 is PE met die RTPA uitgeskakel (p=0.04581), terwyl dit in 89% van pasiënte met V/Q EFERT en planare beelde uitgeskakel is. Gevolgtrekking: Gebaseer op hierdie studie het V/Q planare en EFERT beelding ‘n ooreenstemmende diagnostiese prestasie in pasiënte met ’n normale of naby normale borskas X-straal.

Les bandes de fréquences utilisées conventionnellement pour les systèmes fixes de télécommunication par satellites (bandes C et Ku i.e. 4-15 GHz) sont congestionnées. Néanmoins, le marché des télécommunications civil et de défense accuse une demande de plus en plus importante en services multimédia haut-débit. Par conséquent, l'augmentation de la fréquence porteuse vers les bandes Ka et Q/V (20-40/50 GHz)est activement étudiée. Pour des fréquences supérieures à 5 GHz, la propagation des signaux radioélectriques souffre de l'atténuation troposphérique. Parmi les différents contributeurs à l'affaiblissement troposphérique total(atténuation, scintillation, dépolarisation, température de bruit du ciel), les précipitations jouent un rôle prépondérant. Pour compenser la détérioration des conditions de propagation, des techniques de compensation des affaiblissements (FMT: Fade Mitigation Technique) permettant d'adapter en temps réel les caractéristiques du système en fonction de l'état du canal de propagation doivent être employées. Une alternative à l'utilisation de séries temporelles expérimentales peu nombreuses est la génération de séries temporelles synthétiques d'atténuation due à la pluie et d'atténuation totale représentatives d'une liaison donnée.Le manuscrit est organisé autour de cinq articles. La première contribution est dédiée à la modélisation temporelle de l'affaiblissement troposphérique total. Le deuxième article porte sur des améliorations significatives du modèle de génération de séries temporelles d'atténuation due à la pluie recommandé par l'UITR.Les trois contributions suivantes constituent une analyse critique et une modélisation de la variabilité des statistiques du 1er ordre utilisées lors des tests des modèles de canal. La variance de l'estimateur statistique des distributions cumulatives complémentaires de l'atténuation due à la pluie et de l'intensité de précipitation est alors mise en évidence. Un modèle à application mondiale paramétré au moyen de données expérimentales est proposé. Celui-ci permet, d'une part, d'estimer les intervalles de confiance associés aux mesures de propagation et d'autre part, de quantifier le risque en termes de disponibilité annuelle associée à la prédiction d'une marge de propagation donnée. Cette approche est étendue aux variabilités des statistiques jointes. Elle permet alors une évaluation statistique de l'impact des techniques de diversité de site sur les performances systèmes, tant à microéchelle(quelques kms) qu'à macro-échelle (quelques centaines de kms)
Nowadays, C and Ku bands used for fixed SATCOM systems are totally congested. However, the demand of the end users for high data rate multimedia services is increasing. Consequently, the use of higher frequency bands (Ka: 20 GHz and Q/V 40/50 GHz) is under investigation. For frequencies higher than 5 GHz, radiowave propagation is strongly affected by tropospheric attenuation. Among the different contributors, rain is the most significant. To compensate the deterioration of the propagation channel, Fade Mitigation Techniques (FMT) are used. The lack of experimental data needed to optimize the real-time control loops of FMT leads tothe use of rain attenuation and total attenuation time series synthesizers. The manuscript is a compilation of five articles. The first contribution is dedicated to the temporal modelling of total impairments. The second article aims at providing significant improvements on the rain attenuation time series synthesizer recommended by ITU-R. The last three contributions are a critical analysis and a modelling of the variability observed on the 1st order statistics used to validate propagation channel models. The variance of the statistical estimator of the complementary cumulative distribution functions of rainfall rate and rain attenuation is highlighted. A worldwide model parameterized in compliance with propagation measurements is proposed. It allows the confidence intervals to be estimated and the risk on a required availability associated with a given propagation margin prediction to be quantified. This approach is extended to the variability of joint statistics. It allows the impact of site diversity techniques on system performances at small scale (few kms) and large scale (few hundred of kms) to be evaluated

This thesis examines the linear swimming motion of Carangiform fish, and investigates how to improve the swimming performance of robotic fish within the fields of kinematic modeling and mechanical engineering, in a successful attempt to replicate the high performance of real fish. Intensive research was conducted in order to study the Carangiform swimming motion, where observational studies of the common carp were undertaken. Firstly, a full-body length Carangiform swimming motion is proposed to coordinate the anterior, mid-body and posterior displacements in an attempt to reduce the large kinematic errors in the existing free swimming robotic fish. It optimizes the forces around the centre of mass and initiates the starting moment of added mass upstream therefore increasing performance, in terms of swimming speed. The introduced pattern is experimentally tested against the traditional approach (of posterior confined body motion). A first generation robotic fish is devised with a novel mechanical drive system operating in the two swimming patterns. It is shown conclusively that by coordinating the full-body length of the Carangiform swimming motion a significant increase in linear swimming speed is gained over the traditional posterior confined wave form and reduces the large kinematic errors seen in existing free swimming robotic fish (Achieving the cruising speeds of real fish). Based on the experimental results of the first generation, a further three robotic fish are developed: (A) iSplash-OPTIMIZE: it becomes clear that further tuning of the kinematic parameters may provide a greater performance increase in the distance travelled per tail beat. (B) iSplash-II: it shows that combining the critical aspects of the mechanical drive system of iSplash-I with higher frequencies and higher productive forces can significantly increase maximum velocity. This prototype is able to outperform real Carangiform fish in terms of average maximum velocity (measured in body lengths/ second) and endurance, the duration that top speed is maintained. (C) iSplash-MICRO: it verifies that the mechanical drive system could be reduced in scale to improve navigational exploration, whilst retaining high-speed swimming performance. A small robotic fish is detailed with an equivalent maximum velocity (BL/s) to real fish.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
Nesse trabalho procuramos investigar as contribuiÃÃes da utilizaÃÃo da SequÃncia Fedathi para o ensino da matemÃtica objetivando a elaboraÃÃo de conceitos do sistema de numeraÃÃo decimal por discentes cegos com a utilizaÃÃo do recurso Q.V.L. A metodologia proposta como aporte teÃrico da pesquisa baseia-se em uma prÃtica pedagÃgica que indica a postura do professor como um mediador do ensino favorecendo ao estudante uma elaboraÃÃo ativa dos seus conhecimentos, procurando desenvolver aprendizagem significativa, oportunizando aos estudantes uma maior aproximaÃÃo com conceitos cientÃficos. A sequÃncia Fedathi, foi desenvolvida e encontra-se em constante estudo pelo professor Dr. HermÃnio Borges no LaboratÃrio Multimeios FACED- UFC. A pesquisa abrangeu uma pesquisadora do Mestrado acadÃmico em EducaÃÃo da UFC e desenvolvida em uma instituiÃÃo patrimonial de Fortaleza com duas professoras e 04 alunos com deficiÃncia visual. Os demais teÃricos pesquisados e estudados para o desenvolvimento da pesquisa foram: (AMIRALIAN, 1997; WARREN, 1994, OCHAITA E ESPINOSA, 2004 e BRANDÃO, 2006, 2007, 2009; LIRA E BRANDÃO 2013). Optamos assim por uma pesquisa colaborativa a fim de observarmos a proximidade da pesquisadora com os estudantes atravÃs de intervenÃÃes, com a finalidade de analisar o desempenho dos mesmos para suas elaboraÃÃes de aprendizagem atravÃs de mediaÃÃes do professor onde o estudante passa a ser ativo no processo de ensino e aprendizagem. A coleta de dados foi desenvolvida por intermÃdio de observaÃÃes de episÃdios de ensino, investigaÃÃo bibliogrÃfica, aproximaÃÃo com a famÃlia das crianÃas, e intervenÃÃes atravÃs de sessÃes didÃticas utilizando a SequÃncia Fedathi. Os resultados encontrados nos assinalam expor algumas consideraÃÃes importantes acerca do ensino de MatemÃtica para alunos cegos, que norteiam aos professores uma prÃtica mais voltada para o desenvolvimento de um aluno crÃtico e ativo nas suas elaboraÃÃes. Tivemos a oportunidade durante a pesquisa de avaliarmos que nossos alunos com deficiÃncia visual quando tem a oportunidade de desenvolver conceitos matemÃticos atravÃs de uma mediaÃÃo correta por parte do professor, apresentam condiÃÃes igualitÃrias de aprendizagem e desenvolvem seu conhecimento com significado Diante das implicaÃÃes encontradas consideramos que a postura docente em relaÃÃo ao ato de ensinar deve utilizar metodologias que sua aÃÃo docente esteja pautada num ato de mediador do conhecimento. O estudo assinalou que a postura diferenciada do professor e a utilizaÃÃo de uma metodologia que valorize a relaÃÃo de mediaÃÃo do ensino apresentou um desenvolvimento satisfatÃrio nas elaboraÃÃes de conceitos por alunos cegos. PorÃm percebemos que a mudanÃa de postura do professor à um processo em longo prazo e que necessita da disponibilidade do professor, alÃm de tempo para o planejamento precisa tambÃm de formaÃÃo continuada constante para atender melhor a modalidade de ensino em que leciona e que essa formaÃÃo deve contemplar metodologias de ensino.

This work presents new analytical and computational methods for operation security assessment of electric power systems by considering Angle and Voltage Stability Limits. In the context of Angle Stability, it was developed a method for estimating transient security margins based on equivalent network reduction techniques and coherent generators. The angle speed deviation was the criterion used to identify generators that swing together. The reduced order was accomplished by replacing two clusters of coherent generators by an One-Machine Infinite Bus equivalent system. With this equivalent, critical fault clearing times and security margins are calculated with the aid of the Equal Area Criterion. The results were in a good agreement when compared with others methods, especially those based on Transient Energy Function used as a Lyapunov function. The method was also applied for estimating security margins and critical fault clearing times of power systems in the presence of wind power generation. It was demonstrated that the proposed method can be used to select critical contingencies, where detailed power system models are needed such that it can reproduce the actual behavior of the system. With respect to Voltage Stability, it was developed an analytical and computational method for steady state voltage stability analysis on a P-Q plane. First of all, it was applied on a simple two-bus power system, and the analytical and computational results were compared. Then, a Voltage Stability Index was derived, in order to obtain the security margins of each bus for any operational state of an n-bus power system. It was carried out by using a power system reduction technique. With the Voltage Stability Index, it is possible to identify critical buses and the regions that are prone to voltage collapse. The voltage stability limits of a distribution power system was also analyzed by means of the P-Q curves, by considering different operation scenarios of wind power generation. It was demonstrated that the wind power can contribute to improve the voltage security margins. Finally, the method was applied to a real power system of Companhia Estadual de Distribuição de Energia Elétrica, in the presence of wind power generation. The methods are computationally efficient and suitable for planning, operation and real-time operation of electric power systems.
Este trabalho apresenta novos métodos analíticos e computacionais para a avaliação da segurança da operação de sistemas elétricos de potência considerando os Limites de Estabilidade Angular e de Tensão. No tema Estabilidade Angular, desenvolveu-se um método para a estimativa de margens de segurança transitória baseado em técnicas de redução de redes e geradores coerentes. O desvio de velocidade angular foi o critério usado para identificar geradores que oscilam juntos. A redução foi realizada substituindo-se dois grupos de geradores coerentes por um sistema Equivalente Máquina-Barra Infinita. Com este equivalente, os tempos críticos de abertura de falta e as margens de segurança são calculados com auxílio do Critério das Áreas Iguais. Os resultados encontrados foram muito satisfatórios quando comparados com aqueles obtidos por outros métodos, especialmente os que utilizam a função energia como função de Lyapunov. O método também foi aplicado para a estimativa de margens de segurança e tempos críticos de abertura de falta, em sistemas de potência na presença de geração eólica. Foi demonstrado que o método proposto é capaz de selecionar contingências críticas que precisam ser estudadas com modelos completos de modo a reproduzir o comportamento real do sistema elétrico. Com relação à Estabilidade Tensão, foi desenvolvido um método analítico e computacional para análise de estabilidade estática de tensão no plano P-Q. Primeiramente, o método foi aplicado em um sistema de potência simples com duas barras, e os resultados analíticos e computacionais foram comparados. Então, um Índice de Estabilidade de Tensão foi deduzido, para determinar a margem de segurança de cada barra para qualquer estado de operação de um sistema de potência com n-barras. Com o Índice de Estabilidade de Tensão, é possível identificar barras críticas e regiões com tendência ao colapso de tensão. Os limites de estabilidade de tensão de um sistema de distribuição foram analisados através das curvas P-Q , no qual foram considerados diferentes cenários de operação da geração eólica. Deste modo, foi demonstrado que a geração eólica pode contribuir para melhorar as margens de segurança de tensão. Finalmente, o método foi aplicado em um sistema de potência real pertencente à Companhia Estadual de Distribuição de Energia Elétrica. Os métodos desenvolvidos são computacionalmente eficientes e adequados para o planejamento da expansão e operação, bem como na operação em tempo real dos sistemas elétricos de potência.

CD23 is a multi-functional protein which exists in membrane-bound and soluble forms. Its functions include acting as the low affinity receptor for IgE and generating pro-inflammatory cytokine release in monocytes. CD23 has been found to interact with αvβ5 and this interaction greatly enhances growth of the B cell precursor cell line SMS-SB. This interaction may have a role in the development of normal human B cells and in cancer as the integrin is expressed on both precursor and ALL cells but not on normal mature B cells. One of the aims of this investigation was to expand on the finding that CD23 peptides containing an RKC motif had the same positive growth effect on SMS-SB cells as CD23. Other B cell lines – representative of both precursor and mature stages – were studied to ascertain whether this proliferative effect was dependent upon cell differentiation stage and/or presence of the αvβ5 integrin. It was found that peptides containing the basic RKC motif were mitogenic only for precursor B cells which were expressing αvβ5. Details of these peptides and their varying effects on the different cell lines are in Chapter 4. Stimulation of SMS-SB cells, presumably via the αvβ5, results in signalling through PI3K and subsequent phosphorylation of Akt. The growth of SMS-SB cells observed following stimulation with peptides containing the RKC motif was abrogated by the PI3K inhibitor LY294002 and western blotting revealed that phosphorylation of Akt was enhanced by stimulation with RKS containing peptides. Among CD23’s receptors is the integrin αvβ3. This integrin can form a signalling complex with CD47. Ligation of CD47 by anti-CD47 antibodies induces apoptosis in some cell lines. To determine whether a pattern exists between response to this stimulation and expression of αvβ3 integrin, cell lines with and without the integrin were tested. It was found that the myeloma cell lines KMS11 and H929 were responsive to this stimulus. Since these cell lines differ in their expression of αvβ3 (H929 cells express αvβ3 whereas KMS11 do not) it does not appear that any connection between the presence of the integrin and response via CD47 exists and therefore this signalling mechanism would appear to occur independently of the complex formed by CD47 and αvβ3.

The overall aim of this work was to investigate the synthesis of Laves phase-related BCC solid solution Ti V Mn based alloys for use in hydrogen storage and hydrogen compression applications. In particular, for Ti0.5V0.5Mn-based alloys, the effect of composition, microstructure, and crystallography on the hydrogen sorption properties, were investigated. After investigating seven novel compositions based on Ti-V-Mn, (i.e. Ti\(_{0.5}\)V\(_{0.4}\)TM\(_{0.1}\)Mn, where TM = Nb, Cr, Mo, Ta and Ti\(_{0.5}\)V\(_{0.5-x}\)Nb\(_x\)Mn, where x = 0.05, 0.2 and 0.5) it was found that small amounts (0.05 - 0.1 at%) of Nb substituted for V resulted in smaller hysteresis between absorption and desorption as well as higher hydrogen dissociation pressures. This finding led to the successful development of a two-stage metal hydride compressor utilising one of the novel composition (Nb = 0.05), which is capable of pressurising a cylinder up to 650 bar from an input pressure of less than 10 bar at 0.5 g H\(_2\)/min In summary, these findings confirm that it is possible to tailor the plateau pressure and enthalpy of a metal hydride system formed by alloying Ti-V-Mn with other transition metals.

L'augmentation des besoins en bande passante et la saturation du spectre en bande Ku (12 GHz) pour les nouveaux systèmes de communications par satellite géostationnaires, poussent à l'utilisation de fréquences plus élevées (bande Ka et Q/V, 20 à 50 GHz) où de plus grandes largeurs de bandes sont disponibles, mais où les effets atmosphériques sont importants. Il faut alors définir des techniques adaptatives (FMT : fade mitigation techniques) qui permettent d’optimiser la couche physique du système en prenant en compte les conditions de propagation qui sont variables dans le temps. La définition optimisée de ces techniques adaptatives fait l'objet de cette thèse. Le rapport décrit tout d’abord les caractéristiques principales de la propagation dans ces bandes de fréquences. Les techniques adaptatives sont ensuite analysées. L'analyse s’appuie sur un système de référence multifaisceaux pour l’accès distribué à l’lnternet. Une méthode originale d’évaluation des performances système a été développée pour quantifier l’efficacité de ces techniques et choisir leur meilleure combinaison. L'analyse a révélé le besoin de nouvelles procédures d'optimisation des bilans de liaison qui ont été mises au point. Ainsi l'introduction de l'adaptation du schéma de modulation-codage (utilisant le standard DVB-SZ et une proposition d'extension du DVB-RCS) permet une nette amélioration des résultats en termes de capacité. Après avoir quantifié l’apport de ces techniques de compensation de façon théorique, la dernière partie des travaux de recherche est dédiée à l'implémentation des techniques étudiées. La principale difficulté réside, selon la technique FMT concernée, dans l'obtention de mesures fiables et rapides de la magnitude de l'affaiblissement ou du SNIR, rapport puissance porteuse à puissance du bruit (y compris brouillages). Plusieurs architectures d'implantation des techniques FMT ont été proposées. Les sources d’erreurs associées aux différentes fonctions mises en œuvre dans l'architecture FMT ont été identifiées et quantifiées. À partir de cette analyse, une méthode de définition des seuils et des marges de décision d’activation de chaque technique est proposée. La thèse se termine par les résultats obtenus à partir d’un simulateur de la boucle de contrôle FMT. Les simulations confirment l'amélioration des performances du système grâce à l'introduction des FMT, et mettent aussi en évidence l'intérêt de la proposition de répartition non-uniforme des seuils et des marges pour optimiser la boucle de contrôle FMT.

Introduction: La stratégie diagnostique de l’EP au cours de la grossesse est incertaine du fait du manque d’études solides d’un point de vue méthodologique, et du risque lié à l’irradiation des examens diagnostiques (angioscanner thoracique et scintigraphie pulmonaire). L’enjeu est donc de valider des stratégies performantes d’une part, et d’identifier des marqueurs cliniques permettant de réduire le recours aux examens irradiants d’autre part. Notre premier objectif a été d’identifier les pièges au cours de la stratégie diagnostique de l’EP (baisse de la performance du dosage des D‐dimères, des scores de probabilité clinique et de l’imagerie) au cours de la grossesse. Le deuxième objectif a été de comparer les performances diagnostiques et les risques des deux examens d’imagerie de référence que constituent la scintigraphie pulmonaire et l’angioscanner thoracique. Le troisième objectif a été de valider une stratégie diagnostique permettant une réduction du recours aux examens irradiants (ajustement du taux de D-dimères sur la probabilité clinique). Le dernier objectif a été de mettre en place un programme de recherche centré sur le poids des antécédents familiaux de MVTE, paramètre lui aussi susceptible de réduire le recours aux examens paracliniques. Conclusion : Au terme de ces analyses, nous avons développé un programme de validation d’une stratégie diagnostique de l’EP chez la femme enceinte ; en outre, l’identification d’un ajustement du taux de D‐dimères sur la probabilité clinique ainsi que, en termes de perspective, sur les antécédents familiaux de MVTE a le potentiel de conduire à des stratégies diagnostiques moins irradiantes et plus performantes chez les femmes enceintes ayant une suspicion d’EP
Introduction : The diagnostic strategy for PE during pregnancy is uncertain due to the lack of high quality studies and the risk of radiation exposure with computed tomography pulmonary angiography (CTPA) and ventilationperfusion (V-Q) lung scan. The challenge is to validate diagnostic strategies, and to identify predictive factors to reduce the number of additional imaging tests with radiation exposure.First, we aim to identify pitfalls during the diagnostic strategy of PE (the D-dimer assay threshold, clinical probability scores, imaging) during pregnancy. Second, our objective was to compare the diagnostic efficiency of CTPA and (V-Q) lung scan during pregnancy.Third, our objective was to validate a diagnostic strategy wich reduces the number of imaging tests (adjustment of the D-dimer level on the clinical probability). Finally, the last objective was to set up a research program focused on the weight of the family history of MVTE, that may also reduce the need of additional tests. Conclusion : We identified an ongoing validation protocol with a new diagnostic algorithm in pregnant patients withPE suspicion ; Furthermore, identifying a D-dimer level adjustement as well as a family history of VTE can lead tomore effective diagnostic stragegies with less radiation exposure for pregnant women with suspected PE

The thesis deals with the visualization of biomedical data in MATLAB environment. The thesis contains following statistical methods and their descriptions: P-P plot, Q-Q plot, histogram, box plot, kernel denstity estimation, scatter plot and several time series metrics. Some functions are programmed from buil-in functions of MATLAB and others using external functions, which are changed to fit to this thesis’s purpose. First part of the thesis conserns theoretical background, whereas the second part conserns practical programmed realizations of mentioned functions. The program contains a graphical user interface - GUI, which the thesis describes in detail. The purpose of the GUI is to ensure ease of use and also data processing. The output graphs of GUI are shown in chapter 5. The last part deals with the possible extensions of the program.

The main outcome of this Thesis is a set of Q / h characteristic that was obtained extensive hydraulic model research measuring plate designed for the determination of water flow in circular profiles. The final Q / h characteristic are functions of angle and vertical cut remoteness of the top slot from the bottom of the measurement aperture. Part of the output is an overview of the expected values of uncertainties of measurement in practical use in a specific aperture in sewers and evaluation of impacts involved in determining the overall uncertainty of the flow. The performed hydraulic modeling research is therefore possible to determine Q / h and characteristics for circular sections of larger diameter and to determine their uncertainties when using specific plate. For the design and shape measuring plate of the profile with larger average output is part of a supplement for quick design of specific screens.

This master’s thesis deals with the automatic detection of myocardial infarction in ECG. Semester work consists of two parts. The theoretical part provides a description of the electrical conduction system of the heart, spreading of electrical activity through the heart muscle, the methods of ECG scanning and the ECG curve. There are also mentioned the causes of myocardial ischemia and various methods of its detection. Another part is devoted to high-frequency ECG, analysis of HFQRS and clinical studies which describe the use of high-frequency ECG in diagnosis of myocardial infarction. In the practical part is proposed an algorithm using low-frequency components ECG and an algorithm using high-frequency components ECG for automatic detection of myocardial infarction. The proposed algorithms are implemented in programming environment MATLAB and tested on signals from the PTB database. The final part of the master‘s thesis is devoted to the comparison of the success of myocardial infarction by means of low frequency and high frequency components of ECG and comparison of achieved results with results from clinical studies.

L’exocytose des neurotransmetteurs repose sur la fusion des vésicules synaptiques avec la membrane plasmique en réponse à l’influx calcique qui accompagne les potentiels d’action. La fusion nécessite l’assemblage des protéines SNAREs de la vésicule (la VAMP2) et de la membrane plasmique (la syntaxine 1 et la SNAP25) à l’interface des deux bicouches lipidiques, et elle est déclenchée par la synaptotagmine, un senseur de Ca2+ aux propriétés fusogènes. Des senseurs calciques additionnels semblent participer au déclenchement de la libération et à la dynamique du pore de fusion, en particulier la calmoduline dont le rôle au cours de l’exocytose demeure obscur. Au moyen d’une technique dérivée de la FRET, nous démontrons ici que la Ca2+/calmoduline inhibe l’assemblage du complexe SNARE et la fusion membranaire SNARE-dépendante in vitro en se liant aux domaines juxtamembranaires de la VAMP2 et de la syntaxine 1. De plus des données récentes indiquent que le secteur V0 de la pompe à protons V-ATPase peut participer à la fusion membranaire, et plus particulièrement qu’un hexamère formé de ses sous-unités c constitue un pore capable de libérer de l’acétylcholine en présence de calmoduline. Au moyen des techniques du double-hybride de levure et de SPR notamment, nous avons identifié un lien direct entre boucle 3-4 de la sous-unité c et VAMP2, impliquant le domaine de liaison à la calmoduline de cette dernière. La perturbation de cette interaction in vivo, par injection d’un peptide interférant, inhibe la neurotransmission, suggérant que l’interaction de la machinerie d’exocytose avec ce pore protéique potentiel est impliquée dans la libération des neurotransmetteurs
Action potential-evoked neurotransmitter release relies on Ca2+-driven synaptic vesicle fusion with the plasma membrane. Fusion involves assembly of the vesicular protein VAMP2 (a v-SNARE) with the plasma membrane proteins syntaxin 1 and SNAP25 (t-SNAREs) into a tight trans complex at the interface between the bilayers, and is triggered by synaptotagmin, a fusogenic Ca2+-sensor. Additional Ca2+-sensors are likely to participate in release triggering and fusion pore dynamics, and notably our understanding of calmodulins actions in exocytosis remains elusive. By means of a FRET-derived method, we demonstrate that Ca2+/calmodulin inhibits SNARE complex assembly and SNAREdependent membrane fusion in vitro, by binding to the juxtamembrane regions of VAMP2 and syntaxin 1. The newly-identified calmodulin binding site on syntaxin overlaps with the synaptotagmin- interacting region, and the two interactions are mutually exclusive, suggesting antagonistic roles for the two sensors in membrane fusion. Moreover, recent data point to the involvement of the V0 sector of the proton pump V-ATPase in various membrane fusion events. They indicate that pore-forming c-subunits hexamers confer Ca2+- dependent release of acetylcholine to synthetic liposomes in the presence of calmodulin. Using yeasttwo- hybrid and SPR, we have identified a direct link between the c-subunit loop 3-4 and the v-SNARE VAMP2, involving the calmodulin-binding domain of the latter. Disturbing this interaction in vivo by acute injection of an interfering peptide inhibited neurotransmission, suggesting that association of the exocytotic machinery with the putative proteic pore is involved in neurotransmitter release

This thesis deals with the issue of the creation of a programme that would simulate the distortion that appears during the process of lossy audio coding. As the environment for the creation, the MATLAB programming language has been chosen. An encoder, which changes the subjective signal quality according to customer preferences for the bitrate, has been created as a practical part of this thesis. Its function is based on a dynamic bit allocation technique and includes an optional window switching algorithm. The theoretical background for the creation of the programme consists of an explanation of the main principles of lossy coding with emphasis on MPEG1 layer 3 operating principles. The practical chapter describes how the created programme and its parts work, and it includes results of the run quality testing. The testing was conducted using the objective assessment method PEMO-Q, and consisted of comparing the objective quality of the programme’s outputs to the quality of samples on which a regular MP3 encoder with identical settings was used.

This thesis deals with the utilization of new principles of characterization of gate capacitances for sigma-delta modulators. Sigma-delta modulators are the integral part of sigma-delta analog-to-digital converters. The proposed new method is characterized by high resolution and modest requirements for laboratory equipment. It allows characterizing capacitances whose values are within the range which is used in sigma-delta modulators. The thesis contains description of the new method, the analysis of measurement accuracy and experimental results.

This thesis tackles issues of particular interest regarding analysis and design of passive components at the mm-wave and Terahertz (THz) bands. Innovative analysis techniques and modeling of complex structures, design procedures, and practical implementation of advanced passive devices are presented. The first part of the thesis is dedicated to THz passive components. These days, THz technology suffers from the lack of suitable waveguiding structures since both, metals and dielectric, are lossy at THz frequencies. This implies that neither conventional closed metallic structures used at microwave frequencies, nor dielectric waveguides used in the optical regime, are adequate solutions. Among a variety of new proposals, the Single Wire Waveguide (SWW) stands out due to its low attenuation and dispersion. However, this surface waveguide presents difficult excitation and strong radiation on bends. A Dielectric-Coated Single Wire Waveguide (DCSWW) can be used to alleviate these problems, but advantages of the SWW are lost and new problems arise. Until now, literature has not given proper solution to radiation on bends and, on the other hand, rigorous characterization of these waveguides lacks these days. This thesis provides, for the first time, a complete modal analysis of both waveguides, appropriated for THz frequencies. This analysis is later applied to solve the problem of radiation on bends. Several structures and design procedures to alleviate radiation losses are presented and experimentally validated. The second part of the thesis is dedicated to mm-wave passive components. These days, when implementing passive components to operate at such small, millimetric wavelengths, to ensure proper metallic contact and alignment between parts results challenging. In addition, dielectric absorption becomes significant at mm-wave frequencies. Consequently, conventional hollow metallic waveguides and planar transmission lines present high attenuation so that new topologies are being considered. Gap Waveguides (GWs), based on a periodic structure introducing an Electromagnetic Bandgap effect, result very suitable since they do not require metallic contacts and avoid dielectric losses. However, although GWs have great potential, several issues prevent GW technology from becoming consolidated and universally used. On the one hand, the topological complexity of GWs difficulties the design process since full-wave simulations are time-costly and there is a lack of appropriate analysis methods and suitable synthesis procedures. On the other hand, benefits of using GWs instead of conventional structures are required to be more clearly evidenced with high-performance GW components and proper comparatives with conventional structures. This thesis introduces several efficient analysis methods, models, and synthesis techniques that will allow engineers without significant background in GWs to straightforwardly implement GW devices. In addition, several high-performance narrow-band filters operating at Ka-band and V-band, as well as a rigorous comparative with rectangular waveguide topology, are presented.
Esta tesis aborda problemas actuales en el análisis y diseño de componentes pasivos en las bandas de onda milimétrica y Terahercios (THz). Se presentan nuevas técnicas de análisis y modelado de estructuras complejas, procedimientos de diseño, e implementación práctica de dispositivos pasivos avanzados. La primera parte de la tesis se dedica a componentes pasivos de THz. Actualmente no se disponen de guías de onda adecuadas a THz debido a que ambos, metales y dieléctricos, introducen grandes pérdidas. En consecuencia, no es adecuado escalar las estructuras metálicas cerradas usadas en microondas, ni las guías dieléctricas usadas a frecuencias ópticas. Entre un gran número de recientes propuestas, la Single Wire Waveguide (SWW) destaca por su baja atenuación y casi nula dispersión. No obstante, como guía superficial, la SWW presenta difícil excitación y radiación en curvas. El uso de un recubrimiento dieléctrico, creando la Dielecric-Coated Single Wire Waveguide (DCSWW), alivia estos inconvenientes, pero las ventajas anteriores se pierden y nuevos problemas aparecen. Hasta la fecha, no se han encontrado soluciones adecuadas para la radiación en curvas de la SWW. Además, se echa en falta una caracterización rigurosa de ambas guías. Esta tesis presenta, por primera vez, un análisis modal completo de SWW y DCSWW, adecuado a la banda de THz. Este análisis es aplicado posteriormente para evitar el problema de la radiación en curvas. Se presentan y validan experimentalmente diversas estructuras y procedimientos de diseño. La segunda parte de la tesis abarca componentes pasivos de ondas milimétricas. Actualmente, estos componentes sufren una importante degradación de su respuesta debido a que resulta difícil asegurar contacto metálico y alineamiento adecuados para la operación a longitudes de onda tan pequeñas. Además, la absorción dieléctrica incrementa notablemente a estas frecuencias. En consecuencia, tanto guías metálicas huecas como líneas de transmisión planares convencionales presentan gran atenuación, siendo necesario considerar topologías alternativas. Las Gap Waveguides (GWs), basadas en una estructura periódica que introduce un efecto de Electromagnetic Bandgap, resultan muy adecuadas puesto que no requieren contacto entre partes metálicas y evitan las pérdidas en dieléctricos. No obstante, a pesar del potencial de las GWs, varias barreras impiden la consolidación y uso universal de esta tecnología. Por una parte, la compleja topología de las GWs dificulta el proceso de diseño dado que las simulaciones de onda completa consumen mucho tiempo y no existen actualmente métodos de análisis y diseño apropiados. Por otra parte, es necesario evidenciar el beneficio de usar GWs mediante dispositivos GW de altas prestaciones y comparativas adecuadas con estructuras convencionales. Esta tesis presenta diversos métodos de análisis eficientes, modelos, y técnicas de diseño que permitirán la síntesis de dispositivos GW sin necesidad de un conocimiento profundo de esta tecnología. Asimismo, se presentan varios filtros de banda estrecha operando en las bandas Ka y V con altas prestaciones, así como una comparativa rigurosa con la guía rectangular.
Aquesta tesi aborda problemes actuals en relació a l'anàlisi i disseny de components passius en les bandes d'ona mil·limètrica i Terahercis. Es presenten noves tècniques d'anàlisi i modelatge d'estructures complexes, procediments de disseny, i implementació pràctica de dispositius passius avançats. La primera part de la tesi es focalitza en components passius de THz. Actualment no es disposen de guies d'ona adequades a THz causa que tots dos, metalls i dielèctrics, introdueixen grans pèrdues. En conseqüència, no és adequat escalar les estructures metál·liques tancades usades en microones, ni les guies dielèctriques usades a freqüències òptiques. Entre un gran nombre de propostes recents, la Single Wire Waveguide (SWW) destaca per la seua baixa atenuació i quasi nul·la dispersió. No obstant això, com a guia superficial, la SWW presenta difícil excitació i radiació en corbes. L'ús d'un recobriment dielèctric, creant la Dielecric-Coated Single Wire Waveguide (DCSWW), alleuja aquests inconvenients, però els avantatges anteriors es perden i nous problemes apareixen. Fins a la data, no s'han trobat solucions adequades per a la radiació en corbes de la SWW. A més, es troba a faltar una caracterització rigorosa d'ambdues guies. Aquesta tesi presenta, per primera vegada, un anàlisi modal complet de SWW i DCSWW, adequat a la banda de THz. Aquest anàlisi és aplicat posteriorment per evitar el problema de la radiació en corbes. Es presenten i validen experimentalment diverses estructures i procediments de disseny. La segona part de la tesi es centra en components passius d'ones mil·limètriques. Actualment, aquests components pateixen una important degradació de la seua resposta a causa de que resulta difícil assegurar contacte metàl·lic i alineament adequats per a l'operació a longituds d'ona tan menudes. A més, l'absorció dielèctrica incrementa notablement a aquestes freqüències. En conseqüència, tant guies metàl·liques buides com línies de transmissió planars convencionals presenten gran atenuació, sent necessari considerar topologies alternatives. Les Gap Waveguides (GWs), basades en una estructura periòdica que introdueix un efecte de Electromagnetic Bandgap, resulten molt adequades ja que no requereixen contacte entre parts metàl·liques i eviten les pèrdues en dielèctrics. No obstant, tot i el potencial de les GWs, diverses barreres impedixen la consolidació i ús universal d'aquesta tecnologia. D'una banda, la complexa topologia de les GWs dificulta el procés de disseny atés que les simulacions d'ona completa consumeixen molt de temps i no existeixen actualment mètodes d'anàlisi i disseny apropiats. D'altra banda, és necessari evidenciar el benefici d'utilitzar GWs mitjançant dispositius GW d'altes prestacions i comparatives adequades amb estructures convencionals. Aquesta tesi presenta diversos mètodes d'anàlisi eficients, models, i tècniques de disseny que permetran la síntesi de dispositius GW sense necessitat d'un coneixement profund d'aquesta tecnologia. Així mateix, es presenten diversos filtres de banda estreta operant en les bandes Ka i V amb altes prestacions, així com una comparativa rigorosa amb la guia rectangular.
Berenguer Verdú, AJ. (2017). Analysis and design of efficient passive components for the millimeter-wave and THz bands [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84004
TESIS

Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.

abstract: In the recent past, due to regulatory hurdles and the inability to expand transmission systems, the bulk power system is increasingly being operated close to its limits. Among the various phenomenon encountered, static voltage stability has received increased attention among electric utilities. One approach to investigate static voltage stability is to run a set of power flow simulations and derive the voltage stability limit based on the analysis of power flow results. Power flow problems are formulated as a set of nonlinear algebraic equations usually solved by iterative methods. The most commonly used method is the Newton-Raphson method. However, at the static voltage stability limit, the Jacobian becomes singular. Hence, the power flow solution may fail to converge close to the true limit. To carefully examine the limitations of conventional power flow software packages in determining voltage stability limits, two lines of research are pursued in this study. The first line of the research is to investigate the capability of different power flow solution techniques, such as conventional power flow and non-iterative power flow techniques to obtain the voltage collapse point. The software packages used in this study include Newton-based methods contained in PSSE, PSLF, PSAT, PowerWorld, VSAT and a non-iterative technique known as the holomorphic embedding method (HEM). The second line is to investigate the impact of the available control options and solution parameter settings that can be utilized to obtain solutions closer to the voltage collapse point. Such as the starting point, generator reactive power limits, shunt device control modes, area interchange control, and other such parameters.
Dissertation/Thesis
Masters Thesis Electrical Engineering 2017

The basic concept of the thesis is an analysis of a TV programme "Q" broadcasted by the Czech Television. The programme surveys queer subculture not only in the Czech Republic but also abroad, deals with searching for identities across the genders and disrupts conventions stemming from values of the heteronormative society. The programme title refers directly to the concept of queer, which represents a social phenomenon bringing about gender and sexual diversity and plurality. The thesis looks at the genesis of the programme from its origins, to its production, its broadcasting and finally its cancellation and replacing with another format. The motivation and reasons of the production team and the management for carrying the programme through and including it in the broadcast programming is discussed here, as well as the related decision-making processes and production mechanisms or the way the authors use feminist theories and gender aspects in the programme. The thesis also takes into consideration the long-term development of the programme's ratings. The main working method is qualitative research in the form of semi-structured interviews with the programme's authors. In terms of media production the thesis deals with organizational practices in the programme's production.

NĚMCOVÁ, P. Q-method and its use in destination management of the Vysočina Region. Thesis. Brno: FRRMS MENDELU, 2019 The thesis concerns the Q-method and its use in the field of destination managment as a tool for the segmentation of tourism market. The aim of this work is to identity the groups of respondents in relation to their preferred destination. To evaluate the results of the Q-method, the online statistical method Azabala was used. This method is available online. An additional component of this work is a questionaire. In the thesis, a correlation of the Q-methodological survey with the questionnaire was performed.

碩士
國立臺灣師範大學
應用電子科技學系
101
The purpose of this dissertation is to develop a Power Amplifier and an I/Q Modulator in a V-band millimeter-wave transmitter system. They are fabricated on TSMC 90 nm 1P9M RF CMOS process. With the development of wireless communication technologies, radio frequency integrated circuit tends to higher frequency, higher data rate, wider bandwidth, and higher integration. For this subject, unlicensed multi-GHz bandwidth around V-band makes very high data rate transmission feasible. We adopt CMOS technology. It has the advantages of small size, low cost, low power consumption, and high level of integration, all of which are for MMW applications. To develop a Power Amplifier and an I/Q Modulator in a V-band millimeter-wave transmitter system. We are using Agilent ADS software and SONNET software to be the simulation tools. The first circuit is Power Amplifier, which utilizes three-stage common source configuration amplifier. The first and second stages are drive stages. The third stage is power stage. To purpose higher linearity, we combine a Pre-distortion Linearizer on the power stage. The circuit will have better linearity than without Linearizer. The second circuit is I/Q Modulator, which is using two Modified Gilbert-cell Mixer, one Coupler, and one Wilkinson Combiner.

碩士
國立臺灣大學
電信工程學研究所
93
In this thesis, two transitions from microstrip line to waveguide on Q-band and V-band are presented respectively. One traditional transition between microstrip line and rectangular waveguide is based on the concept of the tapered slot probe antenna and a tri-section transformation on Q-band. With broadband performance and compact size, the antenna is inserted into the E-plane of the end launcher of the waveguide. As the result, one single transition exhibits over 50% bandwidth on Q-band (40-50GHz) for -15dB return loss and approximately 0dB insertion loss in 44-50GHz. Also a back-to-back transition is fabricated to verify the accuracy of the simulation. Good agreement is observed from the comparison between the simulation and measurement results. The other transition is an open-circuited type V-band transition between microstrip line and substrate integrated waveguide (SIW) fabricated on a low temperature co-fire ceramic (LTCC) substrate. The energy is coupled to the waveguide through a via probe from the feeding microstrip line. The stripline pad to the via probe is introduced to improve the transition performance. The structure height of 176-μm which equals 0.073 guided wavelength is very short in the microwave system. One single LTCC transition exhibits 10% bandwidth (58-64GHz in center frequency 60.5GHz) for -15dB return loss and 2dB insertion loss in center frequency. It is found that the relatively high insertion loss of 2dB is mainly attributed to the dielectric loss and can be reduced by adopting low loss tangent material. Numerical results are presented to verify the design idea.

碩士
國立臺灣大學
電信工程學研究所
91
In this research, broadband planar transmission lines to waveguide transitions are developed based on the concept of the tapered slot probe and multi-section transformation. The antenna reported has the broadband performance and compact size. In addition, it’s suitable for most cases no matter the permittivity of the substrate is low or high. When it is used in this structure, one is the antenna inserted into the E-plane of the end launcher of waveguide, and the other is slotline to microstrip or CPW transition. The third part is the slotline used to matched the two part mentioned above for wideband performance. However, when the antenna is used on the high permittivity substrate, the structure must be modified because the bandwidth is limited by the high Q factor of the substrate. To solve this problem, the multi-section transformation is adopted for wideband matching. Besides, for ease of design, the genetic algorithm is used to optimise the performance of the transition. The results optimized by GA are also compared to those realized by the Chebyshev transformers.

This work focuses on high-capacity spectral-efficient Earth-space microwave communication links, supporting the access to wider and less congested bandwidths and providing the required technological advances on radiowave propagation for the design and operation of system-technologies improving the spectral efficiency, proposing the operation of frequency-reuse schemes and polarization diversity techniques at Ka- and Q/V-bands. Because the suitable planning, successful deployment and effective, spectralefficient and interference-free, operation of all space-borne systems and services is necessarily related and directly dependent, although not exclusively, on the propagation channel conditions, this work provides a comprehensive and systematic approach intending the relevant propagation phenomena characterization and understanding, modelling and mitigation. It is proved that there is a bigger operational margin for the operation of the abovementioned system-technologies than what may be believed by considering the international recommended models. Major challenges are envisaged, specially in what concerns the ice-induced depolarization that is more persistent and takes longer than the corresponding rain-induced effects. Nevertheless, their mitigation is possible for which the depolarization shall be the controlling variable. The time lag of 15 minutes is identified as the best trade-off between affordable time and achievable gain in the framework of a time diversity scheme.
Este trabalho foca-se em links de comunicação Terra-espaço em microondas espectralmente eficientes e de elevada capacidade, suportando o acesso a larguras de banda maiores e menos congestionadas e ofereçendo os avanços tecnológicos necessários em termos de propagação de ondas de rádio para o projeto e operação de tecnologias de sistema que visam o uso otimizado do espectro, propondo a operação de esquemas de reuso de frequência e de técnicas de diversidade de polarização nas bandas Ka e Q/V. Porque o adequado planeamento, a implementação bem sucedida, bem como a efetiva operação, espectralmente eficiente e livre de interferências, de todos os sistemas e serviços espaciais está necessariamente relacionada e diretamente dependente, ainda que não exclusivamente, das condições do canal de propagação, este trabalho oferece uma abordagem completa e sistemática pretendendo a caracterização, compreensão, modelação e mitigação dos fenómenos de propagação relevantes. É provado existir uma maior margem operacional para a operação das tecnologias acima mencionadas do que aquela que se acredita existir considerando os modelos internacionais recomendados. São previstos maiores desafios, especialmente no que concerne à despolarização causada por gelo que é mais persistente e que dura mais tempo do que os correspondentes efeitos causados por chuva. De qualquer forma, a sua mitigação é possível e para a qual a despolarização deverá ser a variável de controlo. O intervalo de tempo de 15 minutos é identificado como o melhor compromisso entre tempo acessível e ganho alcançável no contexto de um esquema de diversidade temporal.
Programa Doutoral em Engenharia Eletrotécnica

yes
Voltage instability problems in power system are an important issue that should be taken into consideration during the planning and operation stages of modern power system networks. The system operators always need to know how far the power systems from voltage collapse in order to apply suitable action to avoid unexpected results. This paper propose a review of some static voltage stability indices found in the literature to study voltage collapse reveals that various analytical tools based on different concept to predict voltage collapse phenomena. These static voltage stability indices present reliable information about the closeness of the power system to voltage collapse and identification of the weakest bus, line and area in the power network. A number of static voltage stability indices have been proposed in the literature, but in this only four of them will be considered. The effectiveness of these indices is demonstrated through studies in IEEE 14 bus reliability test system. The results are discussed and key conclusion presented.
MSCRC

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science (MSc), in Emergency Medicine. Johannesburg, 2016
Pulmonary embolism (PE) is a major diagnostic challenge facing emergency medicine physicians. It affects over 900,000 patients every year. Only two-thirds of the patients affected are alive one month after the diagnosis, while only half live to about a year. The exact aetiology is not known, but several risk factors have been implicated in the aetio-pathogenesis of the disease. Furthermore, as this disease has no definitive symptoms or signs, the diagnosis in patients suspected of harbouring a PE is only confirmed or excluded after special investigations. Although anticoagulation is an effective treatment, it has its inherent side-effects and associated morbidity. Thus, it is prudent to utilize clinical scoring systems to direct diagnostic pathways prior to instituting treatment. In this regard, several clinical decisions have been promoted to assist physicians in the workup of a patient with hypoxia. One well advocated rule is the Wells criteria, which consists of seven components, each of which is given a score. All the scores are then added up to give a total, i.e. the Wells score. Based on the Wells score, the clinician is then able to assign a clinical pre-test probability of the patient having PE – i.e. low, medium or high risk. Although a pulmonary angiography offers the only definitive means of establishing a diagnosis of PE, it is not practical to employ such an invasive and expensive technique as a screening test. The V/Q scan has been widely used instead; and, has been shown to be an effective non-invasive procedure for the detection of PE. Patients referred for a ventilation-perfusion scan (V/Q scan) are categorised as having no typical evidence of PE, or very low probability, low probability, intermediate probability or high probability of having a PE. Objective: The study set out to determine the correlation between the probability given by the Wells score and the probability obtained from the V/Q scan results. Methods: The study entails a retrospective analysis of 120 adult patients (>18 years of age), who were referred for a V/Q scan for suspected pulmonary embolism at Charlotte Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath Academic Hospital over a 16 month period. Clinical notes were obtained to ascertain risk factors, presenting symptoms and other data to determine pre-test probability of having a pulmonary embolus. This pre-test probability was categorised according to the Wells score into low, moderate or high risk to provide a more objective measure. The V/Q scan results were obtained from the Nuclear Medicine Department at the health care facility, and these results were subsequently compared to the Wells score in order to establish a correlation between the two parameters, i.e. pre-test probability vs V/Q scan results. Results: The sample population comprised of patients from various age groups, ranging from 18 years to 86 years of age. The median age was 55 years, with almost half of the patients being in the 6th and 7th decades of life. Significant risk factors in our setting were found to be advanced age, history of immobilisation and acute medical illnesses. In the younger population, a history of immobilisation due to trauma or post surgery, and HIV/AIDS were found to be the most significant risk factors. Based on the history, and presenting signs and symptoms, all the patients were initially categorised into low, moderate or high pre-test probability based on the Wells score. The majority of the patients were categorised as moderate risk (59%). Thirty percent (36 patients) were categorised as low risk, and the remainder (11%) as high risk for having a PE. On the V/Q scan results, a total of 74% of patients scanned fell into the low probability, very low probability or no typical evidence category. For the purposes of statistical analysis, these three categories were combined into one category, labelled simply as low probability. Thirteen percent of the patients were classified as intermediate probability and the remaining thirteen percent as high probability on the V/Q scan. On analysis of the data, 80% of patients that were initially categorised as low risk based on the Wells score were also classified as low probability on the V/Q scan results (this category included the low probability, very low probability or no typical evidence categories as mentioned earlier). Of the patients classified initially as high risk on the Wells score, only 15% were also classified as high probability on the V/Q scan results. Conclusion: Of the 120 patients studied, only 15 patients (13%) turned out to have a high probability of PE on the VQ scan. Our study demonstrated good agreement between patients with low risk of PE on the Wells score compared to the low probability of PE on the V/Q scan results. Practically this implies that if a physician finds himself in a health care centre lacking a nuclear medicine facility, he may safely base management decisions in patients with a low pre-test risk of PE on the Wells score. However, there was poor agreement between the moderate and high risk patients compared to the intermediate and high probability of PE on the V/Q scan results, respectively. These patients would require a V/Q scan to guide management decisions. Many factors may have contributed to this poor agreement in our setting. The first factor is the diagnostic workup and inappropriate investigation of patients in the public sector hospitals. Since the patients were referred based solely on presenting signs and symptoms, it is possible that some patients were referred inappropriately for V/Q scans. We do acknowledge that this diagnosis is not always easy clinically in light of the non-specific signs and symptoms. It is for this very reason that clinical decision rules, such as the Wells prediction rule, have been developed in an attempt to improve implicit clinical judgement. The patients in our sample population may not have been referred for a V/Q scan primarily based on the Wells score. Instead, the Wells score was often calculated in retrospect by the investigating departments.
MT2017

碩士
國立清華大學
電機工程學系
103
The droop control method is one of the issues for proper power distributions in isolated microgrids; in this thesis, the P-f/Q-V'droop control method will be analyzed by linearized systems. One salient feature is that the P-f/Q-V'droop control method can effectively regulate the power sharing among the inverters in the microgrid. It indeed solves the problem of the improper reactive power sharing by conventional droop control methods. In order to capture the essential stability issues in the P-f/Q-V'droop control method, the reduced-ordered model is proposed first in this thesis. Then the analysis will be proceeded by the corresponding transfer matrix. Under certain conditions, it can be shown that the stability of the microgrid system can be determined by impedances of transmissions between the inverters and the droop gains. Simulation studies will be performed on Simulink. Techniques about the root locus are utilize to examine the sensitivity of each parameters used in the droop control. In order to validate the proposed method, experimental studies will be conducted by verify the feasibility and the correctness of the proposed method.

碩士
國立中央大學
電機工程學系
106
The use of active and passive millimeter-wave transceivers for detection is a trend. In recent years, semiconductor process technology has matured, and the development of millimeter-wave applications using Silicon processes has also seen new advances. This thesis focuses on the application of millimeter wave injection locking technology in frequency divider and frequency locked loop to achieve low power consumption and low phase noise.Analysis, design and measured results for W-band high-division-ratio divide-by-3 injection-locked frequency divider (ILFD) in Chapter 2. Analysis, design and measured results of a V-band divide-by-6 ILFD are proposed in Chapter 3. Finally, the sub-harmonic injection-locked VCO with FLL self-alignment (SILFLL) are presented in Chapter 4. The V-band divide-by-6 ILFD and SILFLL in this thesis are fabricated using TSMC 90 nm GUTM CMOS process. The W-band ILFD is fabricated using TSMC 40 nm CMOS process. First, frequency dividers and the injection-locked theory are introduced in Chapter 2. Then, the locking range of divide-by-3 is investigated to obtain the design methodology. From the analysis, the locking range of ILFDs is proportional to the device size of the injectors and the amplitude of the injection signal. Using inductor matching improves the locking range of divide-by-3. The proposed W-band divide-by-3 ILFD features a locking range of 10.1 GHz and a 10.2% fractional bandwidth. The power consumption is about 7.2 mW. In Chapter 3, we proposed a V-band divide-by-6 ILFD with low power consumption. The locking range is proportional to the device size of the injectors and the amplitude of the injection signal like in Chapter 2. The free-running oscillation frequency of the proposed ILFD is about 9.5 GHz and phase noise is -67.3 dBc/Hz. The measured locking range is about 5.6 GHz from 54.5 to 60.1 GHz with an input power -5 dBm. When the input signal is 144 GHz, the measured input and output phase noises at 100 kHz offset are respectively -125 and -140 dBc/Hz. The phase noise difference between input and output is about 15 dB, and it agrees with the theoretical calculation (20log6). The core power consumption is about 5.6 mW. A sub-harmonic injection-locked oscillator with frequency-locked loop self-alignment (SILFLL) are presented in Chapter 4. First, the theoretical models and transfer functions of FLL are introduced, then using ADS (advance design system) software with system setup analyses FLL. We can efficiently analyze the opened-loop and closed-loop responses of the FLL system. Furthermore, a theoretical model of the SILFLL is proposed, and used to calculate phase noise and jitter for the comparison of various topologies frequency synthesizer. The measured locked range of the SILFLL is from 33.4 to 35.2 GHz and locking range for each control voltage is about 50 MHz. The measured output power is higher than -7 dBm over the range. When the injection-locked output frequency is 33.9 GHz, the measured phase noise (1 MHz offset) and RMS jitter (integrated from 1 kHz to 40 MHz) are -108.9 dBc/Hz and 144 fs, respectively. The total power consumption is about 70.6 mW.

The aim of this thesis is to investigate molecular mechanism of reactive oxygen species production by flavin dehydrogenases mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) and succinate dehydrogenase (SDH). Together, they represent important source of reactive oxygen species in mammalian mitochondria, but the mechanism of electron leak is still poorly understood. Because mechanisms of reactive oxygen species production by other complexes of respiratory chain are better characterized, they can serve as case studies to get insight into mechanisms of reactive oxygen species by flavin dehydrogenases. Relevant knowledge is therefore summarized in the first part of the thesis. To study the production of reactive oxygen species by the isolated flavin dehydrogenases, we used brown adipose tissue mitochondria solubilized by digitonin as a model. Enzyme activity measurements, hydrogen peroxide production studies by Amplex UltraRed fluorescence and luminol luminescence revealed flavin as the most likely source of electron leak in SDH under in vivo conditions, while we propose coenzyme Q binding site as the site of reactive oxygen species production in the case of mGPDH. Distinct mechanism of this production by the two dehydrogenases is also apparent from induction of reactive oxygen species...

Title: Ranges of joint mobility in the hip and ankle joints and evaluation of flat feet on a podoscope when finding hallux valgus in classical ballet dancers Objectives: The aim of this thesis is to evaluate if selected parameters: passive range of motion (ROM) of rotations in hip joints, Q angle, passive range of motion of plantar flexion in ankle joints and the foot index are connected with the finding of hallux valgus (HV) diagnose. These factors will be compared between two groups of ballet dancers, one with HV and one without the HV diagnose. Methods: This observational case control study involved 30 probands between the age of 20-40 years. The experimental group consisted of classical ballet dances with the HV angle (HVA) >15ř at least on one foot (n1 = 19), in the control group were classical ballet dancers with the HVA <15ř bilaterally (n2 = 11). The HVA, ROM of the rotations in the hip joints, ROM of the plantar flexion in the ankle joints and Q angle were measured by a goniometer. The plantogram was captured by a photograph of the foot while standing on a podoscope and then it was evaluated by the Sztriter-Godunov method. Analysis of the data was done in R software by means of a Welch's Two-Sample t-Test and the correlation was given by Pearson's Correlation Coefficient. Results: Contrary...