Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a design methodology and analysis of electronic circuits applied to outdoor lighting systems using light emitting diodes (LEDs). The goal of topologies developed here is to supply the LEDs from the mains, with high power factor, and from batteries when it is needed. Thus, some topologies employing integrated DC-DC converters and single stage converters are proposed and analyzed. The main application of these topologies is street lighting systems without energy consumption from the mains during the Peak Load Time, feeding the circuit by batteries. Moreover, the batteries can keep the system working during a possible fault in the main power supply, operating as an emergency lighting system. These applications are justified by the reduction in energy demand from the electric power system and by the increase in the lighting system reliability. Throughout the work, the main characteristics of the LED and batteries applied in lighting systems are presented, as well as the specification of the luminaire and the battery bank employed. The design methodology proposed for each topology aims to help the converter design intended for better utilization of semiconductors and reduce the value of the bus capacitor. A critical analysis of the converters is performed in order to evaluate the efficiency of the circuits, the power factor, the voltage and current characteristics of the main devices, and compliance with the IEC 61000-3-2 Class C standard that limits the harmonic content of the input current. Finally, electronic circuits are proposed for the management and control of the lighting system. / Este trabalho apresenta uma metodologia de projeto e análise de circuitos eletrônicos aplicados à iluminação de exteriores empregando diodos emissores de luz (LEDs). O objetivo das topologias desenvolvidas neste trabalho é proporcionar aos LEDs uma alimentação adequada através da rede elétrica, com alto fator de potência, e através de baterias quando necessário. Para isso, são propostas e analisadas algumas topologias empregando conversores CC-CC integrados e de estágio único. Estas topologias têm como principal aplicação sistemas de iluminação pública sem consumo de energia a partir da rede elétrica durante o Horário de Ponta, alimentando o circuito por baterias. Além disso, as baterias podem manter o funcionamento do sistema durante uma possível falha no fornecimento de energia pela rede elétrica, operando como um sistema de iluminação de emergência. Estas aplicações são justificadas pela redução da demanda de energia do sistema elétrico de potência durante horários críticos e aumento da confiabilidade do sistema de iluminação pública. Ao longo do trabalho, as principais características do LED e de baterias aplicadas em sistemas de iluminação são abordadas, juntamente com a especificação da luminária e do banco de baterias empregados. A metodologia de projeto proposta para cada topologia desenvolvida tem por objetivo auxiliar o projeto do conversor visando melhor aproveitamento dos semicondutores e redução do valor do capacitor de barramento. A análise crítica dos conversores é realizada com o objetivo de avaliar a eficiência dos circuitos, o fator de potência, características de tensão e de corrente nos principais componentes e o atendimento à norma IEC 61000-3-2 Classe C que limita o conteúdo harmônico da corrente de entrada. Por fim, são propostos circuitos eletrônicos para o gerenciamento e controle do sistema de iluminação.

This thesis focuses on real-time visual object tracking with emphasis on problems caused by a long-term tracking task. Among theses problems belong primarily an occlusion problem, both the partial and the full one, and appearance changes of the object during the tracking. The work is also concerned with tracking objects of a very limited size and unsteady camera movements. These two particular problems are relatively common when tracking distant objects. A part of this work is also a summary of related work and a proposal of a system with high qualitative stability and robustness to problems mentioned. The proposed system was implemented and the evaluation demonstrated that it is capable of solving these problems partially.

This thesis focuses on fuzzy neural networks. The combination of the fuzzy logic and artificial neural networks leads to the development of more robust systems. These systems are used in various field of the research, such as artificial intelligence, machine learning and control theory. First, we provide a quick overview of underlying neural networks and fuzzy systems to explain fundamental ideas that form the basis of the fields, and follow with the introduction of the fuzzy neural network theory, classification and application. Then we describe a design and a realization of the fuzzy associative memory, as an example of these systems. Finally, we benchmark the realization using the pattern recognition and control tasks. The results are evaluated and compared against existing systems.

Bidirectional transfer in Hindi/Urdu speakers with Czech as a Second Language Nora Melnikova Abstract The aim of this project is to examine the influence of Hindi/Urdu on Czech in advanced Hindi L1 speakers of Czech as a Second Language, as well as the influence of Czech on their respective L1. This is the first project of its kind. So far, there has been no research on Hindi/Urdu L1 speakers of Czech, in spite of the fact that dozens Hindi/Urdu L1-speakers enroll in Czech language courses in India every year and thousands of Hindi/Urdu L1-speakers are permanent or long-term residents of the Czech Republic and have acquired Czech at various levels of proficiency. The practical objective of this thesis is to provide first empirically based insights for teachers of Czech as a Foreign/Second Language to Hindi/Urdu L1-speakers in India and in the Czech Republic, as well as for teachers of other Slavic languages. The study analyzes the language production of 10 Hindi/Urdu L1 speakers who have lived in the Czech Republic for at least 5 years. The analysis is based on recordings of informal conversations. The obtained linguistic data was compared with standard grammatical descriptions of Hindi/Urdu and Czech in order to perform error analysis. With the help of contrastive analysis, errors caused by language...

A digital system is often required to operate under a specific frequency. A ring oscillator can be helpful in this circumstance because it can generate a signal with a specific frequency. However, a ring oscillator is also sensitive to the environment temperature. With the increasing requirement of accuracy and stability, many approaches appear worldwide to make a temperature-insensitive ring oscillator. This thesis project presents an approach to compensate the temperature effect on a Current Starved Ring Oscillator(CSRO). More concretely, we researched how to achieve temperature compensation for CSRO in a digitally-controlled configuration. A Phase Frequency Detector (PFD) block is adapted to sense the frequency difference between the reference frequency and CSRO frequency. Two Charge Pumps (CP)are used to quantify the difference in voltage signal. A Dynamic Comparator block compares the signals from CPs. A following Bidirectional Counter block can count up or down to change the current in CSRO by a four-bit signal. In the end, the CSRO can generate an oscillating signal at the appropriate frequency after some adaptation time. This proposed circuit was realized with AMS 0.35 um CMOS technology and simulated using the Cadence tools. Power consumption, temperature compensation analysis and voltage supply compensation analysis under different temperatures are also performed in the project.

For adjoint calculations, parameter estimation, and similar purposes one may need to reverse the execution of a computer program. The simplest option is to record a complete execution log and then to read it backwards. This requires massive amounts of storage. Instead one may generate the execution log piecewise by restarting the ``forward'' calculation repeatedly from suitably placed checkpoints. This thesis extends the theoretical results of the parallel reversal schedules. First a algorithm was constructed which carries out the ``forward'' calculation and distributes checkpoints in a way, such that the reversal calculation can be started at any time. This approach provides adaptive parallel reversal schedules for simulations where the number of time steps is not known a-priori. The number of checkpoints and processors used is optimal at any time. Further, an algorithm was described which makes is possible to restart the initial computer program during the program reversal. Again, this can be done without any additional computation at any time. Hence, optimal parallel reversal schedules for the bidirectional simulation are provided by this thesis. / Bei der Berechnung von Adjungierten, zum Debuggen und für ähnliche Anwendungen kann man die Umkehr der entsprechenden Programmauswertung verwenden. Der einfachste Ansatz, nämlich das Erstellen einer kompletten Mitschrift der Vorwärtsrechnung, welche anschließend rückwärts gelesen wird, verursacht einen enormen Speicherplatzbedarf. Als Alternative dazu kann man die Mitschrift auch stückweise erzeugen, indem die Programmauswertung von passend gewählten Checkpoints wiederholt gestartet wird. In dieser Arbeit wird die Theorie der optimalen parallelen Umkehrschemata erweitert. Zum einen erfolgt die Konstruktion von adaptiven parallelen Umkehrschemata. Dafür wird ein Algorithmus beschrieben, der es durch die Nutzung von mehreren Prozessen ermöglicht, Checkpoints so zu verteilen, daß die Umkehrung des Programmes jederzeit ohne Zeitverlust erfolgen kann. Hierbei bleibt die Zahl der verwendeten Checkpoints und Prozesse innerhalb der bekannten Optimalitätsgrenzen. Zum anderen konnte für die adaptiven parallelen Umkehrschemata ein Algorithmus entwickelt werden, welcher ein Restart der eigentlichen Programmauswertung basierend auf der laufenden Programmumkehr erlaubt. Dieser Restart kann wieder jederzeit ohne Zeitverlust erfolgen und die entstehenden Checkpointverteilung erfüllen wieder sowohl Optimalitäts- als auch die Adaptivitätskriterien. Zusammenfassend wurden damit in dieser Arbeit Schemata konstruiert, die bidirektionale Simulationen ermöglichen.

L’avènement d’internet suivi des réseaux sociaux a permis un accès facile et une diffusion rapide de l’information par toute personne disposant d’une connexion internet. L’une des conséquences néfastes de cela est la propagation de fausses informations appelées «fake news». Les fake news représentent aujourd’hui un enjeu majeur au regard de ces conséquences. De nombreuses personnes affirment encore aujourd’hui que sans la diffusion massive de fake news sur Hillary Clinton lors de la campagne présidentielle de 2016, Donald Trump n’aurait peut-être pas été le vainqueur de cette élection. Le sujet de ce mémoire concerne donc la détection automatique des fake news. De nos jours, il existe un grand nombre de travaux à ce sujet. La majorité des approches présentées se basent soit sur l’exploitation du contenu du texte d’entrée, soit sur le contexte social du texte ou encore sur un mélange entre ces deux types d’approches. Néanmoins, il existe très peu d’outils ou de systèmes efficaces qui détecte une fausse information dans la vie réelle, tout en incluant l’évolution de l’information au cours du temps. De plus, il y a un manque criant de systèmes conçues dans le but d’aider les utilisateurs des réseaux sociaux à adopter un comportement qui leur permettrait de détecter les fausses nouvelles. Afin d’atténuer ce problème, nous proposons un système appelé DS-Fake. À notre connaissance, ce système est le premier à inclure l’exploration de flux de données. Un flux de données est une séquence infinie et dénombrable d’éléments et est utilisée pour représenter des données rendues disponibles au fil du temps. DS-Fake explore à la fois l’entrée et le contenu d’un flux de données. L’entrée est une publication sur Twitter donnée au système afin qu’il puisse déterminer si le tweet est digne de confiance. Le flux de données est extrait à l’aide de techniques d’extraction du contenu de sites Web. Le contenu reçu par ce flux est lié à l’entrée en termes de sujets ou d’entités nommées mentionnées dans le texte d’entrée. DS-Fake aide également les utilisateurs à développer de bons réflexes face à toute information qui se propage sur les réseaux sociaux. DS-Fake attribue un score de crédibilité aux utilisateurs des réseaux sociaux. Ce score décrit la probabilité qu’un utilisateur puisse publier de fausses informations. La plupart des systèmes utilisent des caractéristiques comme le nombre de followers, la localisation, l’emploi, etc. Seuls quelques systèmes utilisent l’historique des publications précédentes d’un utilisateur afin d’attribuer un score. Pour déterminer ce score, la majorité des systèmes utilisent la moyenne. DS-Fake renvoie un pourcentage de confiance qui détermine la probabilité que l’entrée soit fiable. Contrairement au petit nombre de systèmes qui utilisent l’historique des publications en ne prenant pas en compte que les tweets précédents d’un utilisateur, DS-Fake calcule le score de crédibilité sur la base des tweets précédents de tous les utilisateurs. Nous avons renommé le score de crédibilité par score de légitimité. Ce dernier est basé sur la technique de la moyenne Bayésienne. Cette façon de calculer le score permet d’atténuer l’impact des résultats des publications précédentes en fonction du nombre de publications dans l’historique. Un utilisateur donné ayant un plus grand nombre de tweets dans son historique qu’un autre utilisateur, même si les tweets des deux sont tous vrais, le premier utilisateur est plus crédible que le second. Son score de légitimité sera donc plus élevé. À notre connaissance, ce travail est le premier qui utilise la moyenne Bayésienne basée sur l’historique de tweets de toutes les sources pour attribuer un score à chaque source. De plus, les modules de DS-Fake ont la capacité d’encapsuler le résultat de deux tâches, à savoir la similarité de texte et l’inférence en langage naturel hl(en anglais Natural Language Inference). Ce type de modèle qui combine ces deux tâches de TAL est également nouveau pour la problématique de la détection des fake news. DS-Fake surpasse en termes de performance toutes les approches de l’état de l’art qui ont utilisé FakeNewsNet et qui se sont basées sur diverses métriques. Il y a très peu d’ensembles de données complets avec une variété d’attributs, ce qui constitue un des défis de la recherche sur les fausses nouvelles. Shu et al. ont introduit en 2018 l’ensemble de données FakeNewsNet pour résoudre ce problème. Le score de légitimité et les tweets récupérés ajoutent des attributs à l’ensemble de données FakeNewsNet. / The advent of the internet, followed by online social networks, has allowed easy access and rapid propagation of information by anyone with an internet connection. One of the harmful consequences of this is the spread of false information, which is well-known by the term "fake news". Fake news represent a major challenge due to their consequences. Some people still affirm that without the massive spread of fake news about Hillary Clinton during the 2016 presidential campaign, Donald Trump would not have been the winner of the 2016 United States presidential election. The subject of this thesis concerns the automatic detection of fake news. Nowadays, there is a lot of research on this subject. The vast majority of the approaches presented in these works are based either on the exploitation of the input text content or the social context of the text or even on a mixture of these two types of approaches. Nevertheless, there are only a few practical tools or systems that detect false information in real life, and that includes the evolution of information over time. Moreover, no system yet offers an explanation to help social network users adopt a behaviour that will allow them to detect fake news. In order to mitigate this problem, we propose a system called DS-Fake. To the best of our knowledge, this system is the first to include data stream mining. A data stream is a sequence of elements used to represent data elements over time. This system explores both the input and the contents of a data stream. The input is a post on Twitter given to the system that determines if the tweet can be trusted. The data stream is extracted using web scraping techniques. The content received by this flow is related to the input in terms of topics or named entities mentioned in the input text. This system also helps users develop good reflexes when faced with any information that spreads on social networks. DS-Fake assigns a credibility score to users of social networks. This score describes how likely a user can publish false information. Most of the systems use features like the number of followers, the localization, the job title, etc. Only a few systems use the history of a user’s previous publications to assign a score. To determine this score, most systems use the average. DS-Fake returns a percentage of confidence that determines how likely the input is reliable. Unlike the small number of systems that use the publication history by taking into account only the previous tweets of a user, DS-Fake calculates the credibility score based on the previous tweets of all users. We renamed the credibility score legitimacy score. The latter is based on the Bayesian averaging technique. This way of calculating the score allows attenuating the impact of the results from previous posts according to the number of posts in the history. A user who has more tweets in his history than another user, even if the tweets of both are all true, the first user is more credible than the second. His legitimacy score will therefore be higher. To our knowledge, this work is the first that uses the Bayesian average based on the post history of all sources to assign a score to each source. DS-Fake modules have the ability to encapsulate the output of two tasks, namely text similarity and natural language inference. This type of model that combines these two NLP tasks is also new for the problem of fake news detection. There are very few complete datasets with a variety of attributes, which is one of the challenges of fake news research. Shu et al. introduce in 2018 the FakeNewsNet dataset to tackle this issue. Our work uses and enriches this dataset. The legitimacy score and the retrieved tweets from named entities mentioned in the input texts add features to the FakeNewsNet dataset. DS-Fake outperforms all state-of-the-art approaches that have used FakeNewsNet and that are based on various metrics.

This project investigated the implementation and evaluation of various collision-free path planning algorithms for the Saab Seaeye eM1-7 6-DOF Electric Manipulator (eManip). The primary goal was to enhance the autonomous performance of the eManip by integrating efficient path planning methodologies, ultimately ensuring the avoidance of collisions and manipulator singularities during underwater operations. Key algorithms examined included the Rapidly-exploring Random Trees (RRT) algorithm and its enhanced variants. Through simulation tests in MATLAB and Gazebo, metrics such as planning time, path length, and the number of explored nodes were evaluated. The results highlighted the robustness of Goal-biased and Bidirectional RRT* (Gb-Bd-RRT*), which consistently performed well across various environments. The research also highlighted the correlation between algorithm effectiveness and specific task attributes, emphasizing their adaptability to complex environments. This research contributes valuable insights into the effectiveness of path planning algorithms, informing the selection and integration of viable strategies for 6-DOF robotic manipulators.

This thesis is a study into the response and seismic safety of three-dimensional multi-storey concrete structures under concurrent orthogonal seismic excitations. It employs the nonlinear time-history method as its analysis tools. Time-history analyses rely heavily on their utilised earthquake records. Accordingly, this study examines the different approaches of selecting earthquake suites and develops a methodology of selecting representative earthquake scenarios. This methodology is credibly implemented in selecting a far- and a near field suites representative of the New Zealand seismic hazard. The study investigates the response of 6-, 9- and 12-storey concrete structures of different n-X-bays × m-Y-bays. Bidirectional responses of these considered structures are examined and consequently the current combination rules are scrutinised. Consequently this study strongly recommends the use of the 40-percent combination rule in lieu of the widely used 30-percent rule; and the use of time-history analysis in lieu of quasi/equivalent static and response modal analysis methods to avoid their strong dependence on combination rules. An intensive study is conducted employing the incremental dynamic analysis (IDA) technique to investigate structural demands of interstorey drifts, lateral storey drifts and storey accelerations. The study utilises the developed far-field suite and identifies the 50th and 90th percentile demands. Hence it provides easy-to-use expressions to facilitate rapid calculation of the structural demands and the effects of biaxial interactions. An implementation into the Demand and Capacity Factor Design (DCFD) format is presented that infers confidence in the performance levels of the considered structures. The study also draws attention to the importance of considering storey accelerations as their storey values reach as high as 10 × PGA. A sensitivity study is conducted by repeating the IDA investigation while using the developed near-field suite. Subsequently a comparison between the near- and the far-field results is conducted. The results were markedly similar albeit of less magnitudes until the (seismic hazard) intensity measure IM = Sa(T₁) = 0.4g when the near-field results show sudden flat large increase in demands suggesting a brittle collapse. This is attributed to the higher content of the higher mode frequencies contained in near-field ground motions. Finally, the study examines the (vectorial) radial horizontal shear demands in columns and beam-column joints of the previous far- and near-field studies. The combined radial shear demands in corner, edge and internal columns and joints are evaluated that roughly show a square-root proportional relationship with IM that exhibit somewhat brittle failure at IM ≥ 0.35g. Shears demands in the (4-way) internal columns and the (2-way) corner joints show highest magnitude in their respective class. The results suggest transverse joint shear reinforcement of 1.5, 1.0 and 0.5 of the longitudinal reinforcement of the neighbouring beam respectively for corner, edge and internal joints. An implementation of a proposed practical (and simpler) DCFD format shows satisfactory confidence in columns performance in shear up to IM = 0.35g, conversely to joints unsatisfactory performance in shear at the onset of inelastic behaviour (IM > 0.05g).

The thesis deals with the construction design of reversible swirl turbine used in a tidal range power plant for bidirectional operation. The theoretical part provides an overview of state-of-the-art technologies in the usage of tidal energy, mostly by means of tidal range and stream tidal power plants. It also analyses respective designs of tidal turbines and their advantages and disadvantages. The practical part of the thesis demonstrates individual steps applied when examining loading forces and also shows the design method and strength inspection procedure of the turbine and its parts, especially of the impeller, gears, shafts and bearings. Lastly, the paper outlines the selection approach of the most appropriate water plant generator.