[pt] Em uma série de aplicações, os pontos de dados podem ser representados como distribuições de probabilidade. Por exemplo, os documentos podem ser representados como modelos de tópicos, as imagens podem ser representadas como histogramas e também a música pode ser representada como uma distribuição de probabilidade. Neste trabalho, abordamos o problema do Vizinho Próximo Aproximado onde os pontos são distribuições de probabilidade e a função de distância é a divergência de Kullback-Leibler (KL). Mostramos como acelerar as estruturas de dados existentes, como a Bregman Ball Tree, em teoria, colocando a divergência KL como um produto interno. No lado prático, investigamos o uso de duas técnicas de indexação muito populares: Índice Invertido e Locality Sensitive Hashing. Os experimentos realizados em 6 conjuntos de dados do mundo real mostraram que o Índice Invertido é melhor do que LSH e Bregman Ball Tree, em termos de consultas por segundo e precisão. / [en] In a number of applications, data points can be represented as probability distributions. For instance, documents can be represented as topic models, images can be represented as histograms and also music can be represented as a probability distribution. In this work, we address the problem of the Approximate Nearest Neighbor where the points are probability distributions and the distance function is the Kullback-Leibler (KL) divergence. We show how to accelerate existing data structures such as the Bregman Ball Tree, by posing the KL divergence as an inner product embedding. On the practical side we investigated the use of two, very popular, indexing techniques: Inverted Index and Locality Sensitive Hashing. Experiments performed on 6 real world data-sets showed the Inverted Index performs better than LSH and Bregman Ball Tree, in terms of queries per second and precision.

This essay is a comparative study of Judeo-Christian religion and religions from the ancient Middle East, mainly ancient Sumer/Mesopotamia and Egypt, with focus on the common symbols; the serpent, the cow and the tree. The comparison of the three symbols from different religious traditions highlights that there are both key differences and similarities. The differences and similarities are then explained with the help of professor Yair Zakovitch theory inverted reflections stories also referred to as mirror-narratives, which is an intertextual theory. The application of the theory helps to establish that many of the biblical myths are part of a large collection of polemical literature. A strategy within polemics was to invert symbols and motifs from the so called ”pagan” tradition and associate an old well known motif with the opposite meaning in the later biblical reinterpretations, or what Zakovitch identifies as mirror-narratives. The result of this study shows that the theory mirror-narratives is very fruitful in the comparison of Judeo-Christian religion and ”pagan” religions from the ancient Middle East.

Control and balancing of an inverted pendulum has gained a lot of attention over the past few decades due to its unstable properties. This has become a great challenge for control engineers to verify and test the control theory. To control and balance an inverted pendulum, proportional integrated derivative (PID) method or linear quadratic regulator (LQR) method can be used through which a lot of simulations can be done using the represented theories.Since urban population is increasing at a very alarming rate, there is a need to discover new ways of transportation to meet the future challenges and demands. Scania has come up with a new conceptual bus called NXT which aims to develop a modular vehicle that should configure and re-configure themselves between different transportation tasks. NXT vehicle has front and rear drive modules which can be represented as single axle, two-wheeled vehicles which in-turn can be viewed as an inverted pendulum with a huge Center of Gravity. Controlling and balancing of the pod or drive module precisely and accurately is an interesting challenge since it is an unstable inverted pendulum with huge center of gravity (COG). This behaviour of the system has created a research question whether the module is controllable or not.Therefore this thesis focuses on the possibility of controlling the pod which is a two-wheeled inverted pendulum vehicle with a COG offset. Also, the thesis focuses on the construction, mod-elling, testing and validation of a down-scaled model, what sensors are needed to balance the pod precisely, how the sensors must be integrated with the system and how the pod can be controlled remotely from a certain distance by a human. The developed pod houses the technologies like sensors, BLDC motor controllers, hoverboard, Arduino board and Bluetooth transmitters.The Master Thesis starts by presenting an introduction to the inverted pendulum theories, Scania NXT project, information about the research methods, thesis outline and structure . It continues by describing related literature about the inverted pendulums, segways, hoverboards, motor controllers and Arduino boards. Afterwards, the process of deriving a mathematical model, together with simulation in Matlab, Simulink and Simscape is described. Later, construction of the pod is made and lot of effort is put to run the pod. Since the pod needs to be controlled remotely by a human, a remote controlled systemis implemented via mobile phone using an app and finally the thesis is finished with a conclusion and ideas for future work. / Reglering och balancering av en inverterad pendel har väckt stor uppmärksamhet över de senaste decennierna på grund av dess instabila egenskaper. Det har skapat stora utmaningar för regleringenjörer eftersom området tillåter test och verifikation av diverese lösningar. För reglering och balansering av en inverterad pendel, så kan en regulator med proportionell, integral och derivat (PID) konstanter eller en linjär kvadratisk regulator (LQR) användas tillsammans med simuleringar för att bekräfta teorin.I och med att stadsbefolkningen ökar i mycket hög takt, så uppstår behovet av att uppfinna nya transportmedel för att lösa framtida utmaningar och krav. Scania har tagit fram en ny konceptbuss som heter NXT, med målet att utveckla ett modulfordon som kommer att konfigurera och rekonfigurera sig själva mellan olika transportuppgifter. NXT-fordonet har fram- och bakdriv-moduler som kan representeras som enaxlade tvåhjuliga fordon, vilka i sin tur kan betraktas som en inverterad pendel med en stor massa. Att reglera och balansera drivmodulen på ett noggrant sätt är en utmaning eftersom det är ett mycket instabilt system med enorm massa och en okänd tyngdpunkt. Systemets beteende har skapat en forskningsfråga om modulen är reglerbar eller inte.Denna uppsats fokuserar därmed på möjligheterna att kunna reglera drivmodulen samt vilka begränsningar det finns. Uppsatsen fokuserar också på konstruktion, modellering, testning och validering av en nedskalad modell, vilka sensorer som krävs för att balansera drivmodulem, samt hur sensorerna måste integreras med systemet för att kunna fjärstyra fordonet från ett visst avstånd. Utveckingen av en sådan nedskalad modell berör olika områden såsom sensorer, BLDC-motorstyrenheter, hoverboard balanserings scootrar, Arduino kretskort och Bluetooth-sändare/mottagare.Uppsasten börjar med en introduction om olika inverterade pendel teorier, Scania NXT project, forskningsmetoder, en översikt och övergripande struktur. Vidare fortsätter beskrivining av relaterade litteratur om inverterade pendel, Segway, hoverboard, borstlösa motor styrenheter och Arduino kretskort. Senare fortsätter processen för att härleda matematiska modeller som beskirver systemet, tillsammans med simuleringar i Matlab, Simulink och Simscape. Därefter beskrivs konstruktionen av en nedskalad modell av drivmodulen och beskrivning av nödvändiga processer för att få hårdvara och mjkukvara att fungera ihop. Då fordonen ska ha möjlighet att fjärrstyras, så implementerades en bluetooth enhet tillsammans med en programmerbar mobil applikation. Slutligen avlutas uppsatsen med resultat, slutsats och diskussioner och förslag till framtida arbeten.

Hydrofoiling in general has the potential to revolutionize watercraft in the future since it allows smoother and faster transport on water with less energy consumption than traditional planning hulls. Even if the concept of hydrofoiling has been around since the last century, development in control theory and material science together with increased computing power has led to a growing interest for the technology. Especially in water sports such as speed sailing and surfing due to its superiority in speed and comfort. Researchers and students at the Engineering Mechanics Department at KTH, Royal Institute of Technology, Stockholm are working on a new type of watercraft, utilizing only one single hydrofoil with the intention to minimize drag for faster and smoother rides in various wave and weather conditions. The difficulties lie in understanding the relationship between actuators and the mechanics. This thesis is a continuation work from a previous thesis which designed a control strategy based on a model with 4 degrees of freedom (DOF). Due to simplifications and linearizations, the 4 DOF model was not rich enough to meet the performance requirements. This thesis presents a 6 DOF model by deriving the mechanical equations for the spherical inverted pendulum and actuation from the hydrofoiling module. The inverted pendulum model is a well-known control problem that can be solved with different strategies. By showing that the hydrofoiling concept can be modelled as an inverted pendulum, it is also shown that it can be controlled as an inverted pendulum. The derived model is used together with an Extended Kalman Filter to create an observer. The observer is validated with a spherical inverted pendulum model in Matlab and the block diagram environment, Simulink. Simulation results show that the 6 DOF model is able to produce accurate state estimation of the watercraft even in the presence of stochastic measurement noise. It is also concluded that viscous forces, that arise from the watercraft being partly surrounded by water and partly by air, need further investigation. / Principen för bärplan är att generera lyftkraft från vattnet på samma sätt som flygplansvingar genererar lyftkraft från luften för att lyfta farkostens skrov ur vattnet. Detta minskar motståndet från friktionen mellan skrov och vatten vilket möjliggör snabbare och jämnare transport på vatten med en lägre energiförbrukning än traditionella planande skrov. På senare år har tekniken fått ett uppsving i och med framsteg inom strömningsmekanik, reglerteknik och materiallära. Detta i takt med datorers ökande beräkningskraft har lett till att bärplanskonstruktioner har kunnat uppvisa en överlägsenhet i vattensporter som kappsegling och surfing när det kommer till fart och komfort. Forskare och studenter på avdelningen för farkostteknik och solidmekanik vid Kungliga Tekniska Högskolan, Stockholm arbetar med att ta fram en ny typ av farkost med en minimal bärplansdesign, FoilCart. Dess utformning gör att det mekaniska beteendet kan liknas vid en inverterad pendel, vilket är ett välkänt, olinjärt reglerproblem som kan lösas på flera sätt. Denna avhandling är ett vidarearbete som bygger på en modell med fyra frihetsgrader från en tidigare avhandling kring FoilCart-projektet. Modellen med fyra frihetsgrader var, på grund av förenklingar och linjärisering av systemdynamiken, bristfällig och kunde inte garantera en robust balansering av farkosten förutom i linjäriseringspunkten. Modellen som presenteras i denna avhandling har sex frihetsgrader. Mekaniken och systemdynamiken härleds från den sfäriska inverterade pendeln tillsammans med styrningen från bärplansmodulen, utan förenklingar och linjärisering. Modellen används i ett Kalmanfilter för att konstruera en observatör för tillståndsrekonstruktion. Den framtagna modellen valideras med en FoilCart-modell i Simulink. Resultaten visar att observatören kan ge en noggrann tillståndsrekonstruktion även vid simulerat mätbrus i mätsignalen. Avhandlingen syftar till att visa hur den inverterade pendelmodellen kan användas vid framtida implementation av rekonstruerad tillståndsåterkoppling. I och med avgränsningar i avhandlingen finns det också en del strömningsmekaniska aspekter som inte tagits med vid framtagningen av denna modell. Eftersom farkosten delvis är omgiven av vatten och delvis av luft skulle det vara intressant att undersöka om noggrannheten i tillståndsrekonstruktionen kan förbättras genom att använda avancerad strömningsmekanik.

The rapidly growing demand for UWB as high data rates wireless communications technology, since the Federal Communications Commission (FCC) allocated the bandwidth of UWB from 3.1GHz to 10.6 GHz. Antenna also plays an essential role in UWB system. However, there are some difficulties in designing UWB antenna as compared to narrowband antenna. The primary requirement of UWB antennas is be able to operate over frequencies released by the FCC. Moreover, the satisfaction of radiation properties and good time domain performance over the entire frequency range are also necessary. In this thesis, designing and analysing printed crescent shape monopole antenna, Planar Inverted F-L Antenna (PIFLA) and Planar Inverted FF Antenna (PIFFA) are focused. A Planar Inverted FF Antenna (PIFFA) can be created to reduce the potential for interference between a UWB system and other communications protocols by using spiral slot. The antennas exhibits broadside directional pattern. The performances such as return loss, radiation pattern and current distribution of the UWB antennas are extensively investigated and carried out. All the results have been demonstrated using simulation and experimentally whereby all results satisfy the performance under - 10dB point in the bandwidth of UWB. In addition the miniaturization of MIMO/diversity Planar Inverted-F antenna (PIFA) which is suitable for pattern diversity in UWB applications is presented. This antenna assembly is formed by two identical PIFAs, a T-shaped decoupling structure which connects the two PIFAs and a finite ground plane with a total compact envelope dimension of 50 ¿ 90 ¿ 7.5mm3. The radiation performance of the proposed MIMO antenna was quite encouraging and provided an acceptable agreement between the computed and measured envelope correlation coefficient and channel capacity loss. / General Secretariat of Education and Scientific Research Libya

General Secretariat of Education and Scientific Research, Libya. / The only available copy is the print version kept in the J.B.Priestley Library for reference.

With the development of technology and availability of data, it is sometimes easier to learn the control policies directly from the data, rather than modeling a plant and designing a controller. Modeling a plant is not always possible due to the complexity of the plant. Data-enabled predictive control (DeePC) is a recently proposed approach that combines system identification, estimation, and control in a single optimization problem. DeePC is primarily designed for LTI systems. The purpose of this thesis is to extend the application of DeePC to nonlinear systems with a particular focus on a non-holonomic ground robot. To reach this goal, we decompose the system states into different working modes where each mode can be linearly approximated. Furthermore, the data collection policies were also evaluated to conclude how they affect the performance of the DeePC. We identified several key challenges in this direction, namely: data-demanding structure, high computational complexity, and performance deterioration with increased non-linearity. While these challenges prohibited the application of DeePC to the ground robot system; we successfully applied the method to a benchmark non-linear system, the inverted pendulum on cart problem, and studied the effect of various design choices on control performance. Our observations indicate potential areas of improvement toward enabling DeePC for highly nonlinear systems. / Med utvecklingen av teknik och tillgänglighet av data är det ibland enklare att lära sig styrpolicyerna direkt från data, snarare än att modellera ett system och designa en styrenhet. Att modellera ett system är inte alltid möjligt på grund av systemets komplexitet. Data aktiverad prediktiv kontroll (DeePC) är en nyligen föreslagen metod som kombinerar systemidentifiering, uppskattning och kontroll i ett enda optimeringsproblem. DeePC är främst designad för LTI-system. Syftet med denna avhandling är att utöka tillämpningen av DeePC till icke-linjära system med särskilt fokus på en icke-holonomisk markrobot. För att nå detta mål delar vi upp systemtillstånden i olika arbetslägen där varje läge kan approximeras linjärt. Dessutom utvärderades datainsamlingspolicyerna för att dra slutsatser om hur de påverkar DeePCs prestation. Vi identifierade ett antal nyckelutmaningar i denna riktning, nämligen: datakrävande struktur, hög beräkningskomplexitet och prestandaförsämring med ökad icke-linjäritet. Även om de utmaningerna hindrade tillämpningen av DeePC på markrobot systemet; har vi framgångsrikt tillämpat metoden på ett benchmark icke-linjärt system, problemet med inverterad pendel på vagn, och studerade effekten av olika designval på kontrollprestanda. Våra observationer indikerar potentiella förbättringsområden för att möjliggöra DeePC för mycket olinjära system.

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This Master`s thesis is focused on through acquaintance of principles of the function circuits with switched capaticors and posibility of their application mainly in frequency filters or signal generators. The origin of the switched capacitor circuits is mentioned at the beginning of the work. There are references to the first scientific work and scientists who have dealt with this issue. Maxwell`s idea: lossy element (resistor) replace with lossless element (switched capacitor) in electric circuit, is further described. In the next chapter of this work are listed types of switching capacitors and their use in simple RC filters and in structures of inverted or noninverted integrators and their application in more complex higher order filters. The advantages and disadvantages of SC circuits versus circuit composed of discrete components are shown. It is also listed a simple low-pass switched RC filter implemented with analogue multiplexer 4053. Using the LTC1043 integrated circuit, which structure and properties are described and analyzed in detail in the work, the 1st order aktive or pasive low and high pass filters were designed and subsequently simulated in the computer simulator OrCAD PSpice v.10. Another chapter deals with the integrated circuits higher order filters, structure and properties of the integrated filter LTC1060 are further analyzed here. Except this IC there are mentioned integrated filters commercially less available from the corporations Linear Technology and Maxim. The main objective of thesis was to propose and establish laboratory device and laboratory measurment focused on the switched capacitor circuits. The laboratory device has been designed with integrated circuits LTC1043 and LTC1060, which is demonstrated by using passive and active integrator, 2nd order band-pass and 4th order band-pass with Chebyshevovou approximation.

Den Kern der vorliegenden Arbeit bilden sog. sensorgeführte Roboterbewegungen, d. h. die Nutzung von Informationen externer Sensoren zur Regelung des Roboters. Da gängige Industrierobotersysteme üblicherweise positionsgeregelt sind und seitens der Robotersteuerung lediglich der Zugriff zu den Sollwerten der Lageregelkreise erlaubt wird, kann auch der Regelkreis der sensorgeführten Roboterbewegung nur über den Lageregelkreis geschlossen werden. Aus diesem Grunde werden hier nur positionsbasierte Regelungsansätze verfolgt. Die Kraft-/ Momentregelung gilt als eine der wichtigsten Varianten sensorgeführter Roboterbewegungen. Dementsprechend widmet sich auch ein großer Teil dieser Arbeit dem Thema, mit dem Ziel durch innovative und übersichtliche Regelalgorithmen die Akzeptanz der Kraft-/ Momentregelung in industriellen Produktionsprozessen zu erhöhen. Beginnend mit der eindimensionalen Kraftregelung führt der Weg dabei über Konzepte zur Konturenverfolgung und kraft-/ momentgeregelten Montageaufgaben hin zur Kooperation von Robotern. In einem weiteren Teil wird ein Konzept zur Kollisionsvermeidung zwischen Robotern und Hindernissen präsentiert. Es basiert auf dem Ansatz der virtuellen Potential- bzw. Kraftfelder. Dabei ruft das künstliche Feld eine Bewegung des Roboters hervor, die vom Hindernis weg führt. Um das Feld zu erzeugen, wird die Methode der künstlichen Punktladungen entwickelt. Diese werden auf der Oberfläche eines Hindernisses platziert und generieren dann das virtuelle Kraftfeld. Die Platzierung kann z. B. mithilfe der CAD-Daten des Hindernisses erfolgen. Bei bewegten Objekten müssen alle Ladungspositionen ständig aktualisiert werden. Für Lehr- und Präsentationszwecke ist das sog. inverse Pendel eine oft genutzte Regelstrecke. Sein Aufrichten und Stabilisieren ist auch mit Hilfe eines Industrieroboters möglich. Dazu beschäftigt sich ein Kapitel dieser Arbeit mit Fragen zur Modellbildung der Kombination inverses Pendel und Industrieroboter und mit Regelungskonzepten für das Aufschwingen und Balancieren. Letztendlichen wird in diesem Zusammenhang noch ein Visual-Servoing System präsentiert, dass den Neigungswinkel des Pendels mit einer Kamera bestimmt. Alle hier vorgestellten Konzepte und Algorithmen werden Anhand von praktischen Experimenten verifiziert. / This work deals with so-called sensor guided robot motions, which means using the data of external sensors to control the robot. The control loop of the sensor guided robot motion can be only closed around the position control loop, because industrial robot systems usually work position controlled and only access to the desired positions is enabled. For this reason here only position based control approaches are regarded. Force/torque control is a very important type of sensor guided robot motions. According to this, a good portion of this work deals with the subject of force/torque control. Thus, the acceptance of force/torque control in industrial production processes should be increased, by using innovative and clear control algorithms. For this purpose force control in one degree of freedom, contour-following, force/torque controlled assembling tasks and the cooperation between robots are discussed here in different chapters. Thereafter, a concept to collision avoidance between robots and obstacles is presented. It uses the approach of virtual potential/force fields. In this case the artificial field induces a robot motion away from the obstacle. The method of artificial charges is developed to generate this field. For this purpose virtual charges are placed on the surface of the obstacles. Placing of the charges can be performed using e.g. CAD data of the obstacles. Having moving obstacles charge positions must be updated continuously. The inverted pendulum is commonly used teaching students in control theory. The swinging up and the stabilization of the pendulum also can be performed by an industrial robot. One chapter of this work deals with modelling of the robot mounted inverted pendulum and control algorithms for its swinging up and its stabilization. Finally, in combination with the inverted pendulum a visual-servoing system is presented, which measures the pendulum inclination angle by camera. All concepts introduced in this work are verified by practical experiments.