Power distribution networks (PDNs) are conducting structures employed in semiconductor systems with the aim of providing circuits with reliable and constant operating voltage. This network has non-neglible electrical parasitics. Consequently, when digital circuits inside the chip switch, the supply voltage delivered to them does not remain ideal and exhibits spatial and temporal voltage fluctuations. These fluctuations in the supply voltage, known as the power-supply noise (PSN), can affect the functionality and the performance of modern microprocessors. The design of this PDN in the chip is an important part in ensuring power integrity. Modeling and simulation of the PSN in on-chip PDNs is important to reduce the cost of processors. These PDNs have irregular geometries, which affect the PSN. As a result, they have to be modeled. The problem sizes encountered in this simulation are usually large (on the order of millions), necessitating computationally efficient simulation approaches. Existing approaches for this simulation do not guarantee at least one of the following three required properties: computationally efficiency, accuracy, and numerically robustness. Therefore, there is a need to develop accurate, numerically robust, and efficient algorithms for this simulation. For many interconnects (e.g., transmission lines, board connectors, package PDNs), only their frequency responses and SPICE circuits (e.g., nonlinear switching drivers, equivalent circuits of interconnects) terminating them are known. These frequency responses are usually available only up to a certain maximum frequency. Simulating the electrical behavior of these systems is important for the reliable design of microprocessors and for their faster time-to-market. Because terminations can be nonlinear, a transient simulation is required. There is a need for a transient simulation of band-limited frequency-domain data characterizing a multiport passive system with SPICE circuits. The number of ports can be large (greater than or equal to 100 ports). In this simulation, unlike in traditional circuit simulators, normal properties like stability and causality of transient results are not automatically met and have to be ensured. Existing techniques for this simulation do not guarantee at least one of the following three required properties: computationally efficiency for a large number of ports, causality, and accuracy. Therefore, there is a need to develop accurate and efficient time-domain techniques for this simulation that also ensure causality. The objectives of this Ph.D. research are twofold: 1) To develop accurate, numerically robust, and computationally efficient time-domain algorithms to compute PSN in on-chip PDNs with irregular geometries. 2) To develop accurate and computationally efficient time-domain algorithms for the causal cosimulation of band-limited frequency-domain data with SPICE circuits.

abstract: Toward the ambitious long-term goal of a fleet of cooperating Flexible Autonomous Machines operating in an uncertain Environment (FAME), this thesis addresses various control objectives for ground vehicles. There are two main objectives within this thesis, first is the use of visual information to control a Differential-Drive Thunder Tumbler (DDTT) mobile robot and second is the solution to a minimum time optimal control problem for the robot around a racetrack. One method to do the first objective is by using the Position Based Visual Servoing (PBVS) approach in which a camera looks at a target and the position of the target with respect to the camera is estimated; once this is done the robot can drive towards a desired position (x_ref, z_ref). Another method is called Image Based Visual Servoing (IBVS), in which the pixel coordinates (u,v) of markers/dots placed on an object are driven towards the desired pixel coordinates (u_ref, v_ref) of the corresponding markers. By doing this, the mobile robot gets closer to a desired pose (x_ref, z_ref, theta_ref). For the second objective, a camera-based and noncamera-based (v,theta) cruise-control systems are used for the solution of the minimum time problem. To set up the minimum time problem, optimal control theory is used. Then a direct method is implemented by discretizing states and controls of the system. Finally, the solution is obtained by modeling the problem in AMPL and submitting to the nonlinear optimization solver KNITRO. Simulation and experimental results are presented. The DDTT-vehicle used within this thesis has different components as summarized below: (1) magnetic wheel-encoders/IMU for inner-loop speed-control and outer-loop directional control, (2) Arduino Uno microcontroller-board for encoder-based inner-loop speed-control and encoder-IMU-based outer-loop cruise-directional-control, (3) Arduino motor-shield for inner-loop speed-control, (4) Raspberry Pi II computer-board for outer-loop vision-based cruise-position-directional-control, (5) Raspberry Pi 5MP camera for outer-loop cruise-position-directional control. Hardware demonstrations shown in this thesis are summarized: (1) PBVS without pan camera, (2) PBVS with pan camera, (3) IBVS with 1 marker/dot, (4) IBVS with 2 markers, (5) IBVS with 3 markers, (6) camera and (7) noncamera-based (v,theta) cruise control system for the minimum time problem. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2016

O trabalho anteriormente realizado pelo nosso grupo, onde foram simulados defeitos de nitrogênio em nanotubos de carbono, apresentou resultados interessantes relativos às energias e propriedades eletrônicas. A interpretacão dos resultados teóricos obtidos levou à proposta da Divacância rodeada por 4 Nitrogênios como estrutura mais estável para o nitrogênio tipo piridina, em constraste com aquela proposta pelos experimentais, uma Monovacância rodeada por 3 Nitrogênios. Os cálculos das propriedades eletrônicas da Divacância reproduziram as medidas experimentais na investigação de sensores de amônia. Dessa forma, como informação adicional na determinaçã da estrutura mais estável, o presente trabalho investigou as propriedades vibracionais daqueles sistemas que apresentaram menor energias de formação. Foram calculadas as freqüências vibracionais dos seguintes três defeitos: Nitrogênio Substitucional (1N), Monovacância rodeada por 3 Nitrogênios (3NV) e Divacância rodeada por 4 Nitrogênios (4ND) e comparadas com os resultados para os tubos puros. Utilizou-se a aproximação de supercélula, com 140 átomos para um tubo metálico (5,5) e 160 para um tubo semicondutor (8,0). Como o objetivo é identificar as características de cada sistema, focalizou-se na comparação dos valores das freqüências Raman ativas mais intensas. Os cálculos foram realizados com o código SIESTA, utilizando DFT com o formalismo dos pseudopotenciais e a aproximação GGA-PBE. As freqüências foram obtidas pelo Método Direto pelo mesmo programa. Os resultados mostraram diferenças quanto à quebra de degenerescências, que ocorre devido à quebra da simetria do sistema puro e quanto à mudança dos valores das freqüências dos modos. Como característica geral, os defeitos fazem com que as freqüências da banda mais baixa de energia do espectro Raman sofram shifts negativos, ou seja, afastam os picos para energias mais baixas. O modo de freqüência intermediária sofre um shift positivo e os modos da banda G voltam a apresentar valores negativos. Os splittings, bem como os valores numéricos dos shifts variam conforme o tipo de defeito e o tipo de sistema dopado (armchair ou zig-zag). Apesar de não apresentar diferenças consideravelmente grandes para os valores de shifts e splittings entre os defeitos, o comportamento qualitativo distinto para os modos RBMs é uma boa ferramenta para a diferenciação desses defeitos através de espectroscopia vibracional. / A previous work developed in our own group on which nitrogen defects on carbon nanotubes were simulated presented very interesting results regarding the energetics and the electronic properties. The interpretation of the theoretical outcomes led us to propose the Divacancy surrounded by 4 nitrogen atoms as the most stable structure for a pyridine-like nitrogen, in contrast to the one proposed by the experimentalists, namely the Monovacancy surrounded by 3 nitrogen atoms. Calculations of the electronic properties of the Divacancy have reproduced the experimental data. In this way as additional information for determining the actual most stable structure the present work investigated the vibrational properties of those systems that showed the lowest formation energies. We performed the calculations of the vibrational frequencies for the following three defects: Substitutional nitrogen atom (1N), Monovacancy surrounded by 3 nitrogen atoms (3NV) and Divacancy surrounded by 4 nitrogen atoms (4ND). Then the frequencies were compared to those ones from the pure tubes. We used the supercell approximation with 140 atoms for a (5,5) metallic tube and 160 for a (8,0) semiconducting tube. Since the present work aims to identify the main features of each system we focused on the comparison of the values of the strongest Raman active modes. All the calculations were carried out by the SIESTA code, using DFT with the pseudopotential formalism and GGA approximation. Then the frequencies were evaluated using the Direct Method. The results showed differences on the degeneracy splittings, which are caused by the symmetry-breaking due to the introduction of defects, and also differences on the shifts of the numerical values of the frequencies. As general feature, the defects caused the low band frequencies modes of Raman spectrum to have a negative shift, i.e. they push the peaks further to lower energies. The intermediate mode shifts positively and the G band modes show negative shifts again. The splittings as well as those shifts change depending on the type of the defect and the type of the doped system (armchair or zig-zag). Although not showing significant differences for shifts and splittings between the defects, the qualitatively distinct behavior for RBMs modes is a good tool to tell them apart using vibrational spectroscopy.

Objetivo: Este estudo se propõe a verificar a influencia do tipo de luz fotopolimerizadora na força de retenção de pinos intra-radiculares, tanto na técnica direta como na direta indireta. Métodos: 40 raízes de dentes bovinos com comprimento de 12 mm foram tratadas endodonticamente e divididas aleatoriamente em 4 grupos de acordo com a técnica de obtenção dos pinos e luz fotopolimerizadora (n=10): grupo 1 (técnica direta associada à lâmpada halogena); grupo 2 (técnica direta ao LED); grupo 3 (técnica direta-indireta associada à lampada halógena); e grupo 4 (técnica direta-indireta associada ao LED). A força de retenção foi determinada através do teste de tração usando Universal Testing Machine (Instron). Todos os dados foram analisados usando one-way analysis of variance (ANOVA) com a significância de p<0.05 e complementadas com teste de Tukey. Após o teste, as interfaces adesivas onde ocorreram as falhas foram examinadas e classificadas. Resultado: Os grupos 3 (246,05N ± 29,51) e 4 (241,60N ± 28,95) não apresentaram força de retenção estatisticamente diferente mas foram maiores que os grupos 1 (142,30N ± 25,60) e 2 (178,56N ± 25,67). A maior parte das fraturas ocorreu na interface dentina/resina. Conclusão: Com base nos resultados obtidos, concluímos que o método direto-indireto proporcionou a melhor retenção dos pinos de fibra de vidro. / Objectives: The purpose of this study is to verify the influence of light curing type on retention force of direct technique and direct-indirect technique. Methods: Fourth bovine single root teeth with 12mm of length were used in this study. The roots were endodontically treated and randomly divided in four groups according to the light curing unit and technique used: group 1(direct technique, halogen lamp), group 2(direct technique, LED), group 3(direct-indirect technique, halogen lamp), group 4(direct-indirect technique, lamp). The retention force was determined sing a Universal Testing Machine (Instron). All data were analyzed using one-way analysis of variance (ANOVA) and Tukey test. After the test, the failure was examined and classified according to the fracture place: post/ resin; resin/dentin; mix. Results: Group 3 (246,05N ± 29,51) and 4(241,60N ± 28,95)4 (95,18N) did not show statistically difference but presented higher retention force than group 1 (142,30N ± 25,60) and 2 (178,56N ± 25,67). Most of fracture occurred in interface between dentin/resin. Conclusion: Based on the obtained results, it was concluded that adhesive cementation technique influenced in the retention of glass fiber post.

This diploma thesis deals with the problems associated with acquisition of experimental data from technological unit for biomass combustion with nominal capacity of 1 MW, with regard to determination of thermal efficiency. In the introduction part, parameters of currently available biomass-based fuels as well as of those with large potential in the future are summarized. Further, a review in the field of biomass combustion technology is given. Biomass boilers are compared according to their technical parameters, function and benefits and drawbacks. In theoretical part methods for determination of thermal efficiency by direct method, indirect method and modified indirect method are described. Main parameters influencing resultant values of efficiency are included into the analysis. In final part an evaluation of real operational data from prototype unit combusting wooden chips is made. Recommendations for further experimental data gathering and their processing with the aim to evaluate thermal efficiency are suggested.

The stability with respect to a part of variables in the critical case of pair of pure imaginary and single zero roots is researched. Also case of double zero roots with two solution groups and case of two pairs of pure imaginary roots are considered. Particular conditions of the partial asymptotic stability groups) and the partial instability were obtained. In conclusion, we give an example of solving the problem. / Исследуется устойчивость относительно части переменных в критическом случае пары чисто мнимых и одного нулевого корней. Также рассмотрены случай двойного нулевого корня с двумя группами решений и случай двух пар чисто мнимых корней. Для данных случаев получены частные условия асимптотической устойчивости по части переменных и неустойчивости. В заключение приведен пример решения задачи.

Исследуется устойчивость относительно части переменных в критическом случае двойного нулевого корня (m=2). Рассмотрены случаи двойного нулевого корня с одной и с двумя группами решений. Для данных случаев получены частные условия асимптотической устойчивости по части переменных (при двойном нулевом корне с двумя группами решений) и неустойчивости (при двойном нулевом корне с одной группой решений). / The stability with respect to a part of variables in the critical case of double zero roots (m=2) is investigated. Cases of double zero roots with one solution group or two solution groups are considered. Particular conditions of the partial asymptotic stability (case of two solution groups) and the partial instability (case of one solution group) were obtained.

Renewable energy is playing an increasingly significant role in power system operation and stability assessment with its numerous penetration expansion. This is not only brought by its uncertain power output and inverter-based equipment structures but also its operation characteristics like Low Voltage Ride Through (LVRT). It is thus necessary to take these characteristics into consideration and further to find more adaptive schemes to implement them for more effective analysis and safer power system operation. All the aforementioned is based on the accurate identification of the system fundamental information. In this dissertation, a systematic approach is proposed to find the valid system model by estimating the transmission line parameters in the system with PMU measurements. The system transient stability assessment is conducted based on this validated model. The constrained stability region is estimated with Lyapunov functions family based method in the center of angles reference frame considering renewables LVRT as operation limits. In order to integrate the LVRT constraints, a polytopic inner approximation mechanism is introduced to linearize and organize the transformed constraints in state space, which brings much scalability to the whole process. From the voltage stability perspective, an approach to adaptively adjust LVRT settings of the renewable energy sources in the system is formulated to guarantee the system load margin and thus the voltage security. A voltage prediction method is introduced for critical renewable energy sources identification. Estimation methods based on interpolation and sensitivities are developed and conducted for saving computation effort brought by continuation power flows. Multiple test cases are studied utilizing the proposed approaches and results are demonstrated. / Doctor of Philosophy / Renewable energy utilization is continuously rising nowadays. They are clean but highly dependent on natural resources, which causes their uncertainty and intermittence in electric power output. The power system, on the other hand, is designed for schedulable and controllable power generators, which make the traditional methods for system operation and analysis of the system stability much less effective facing the trend of renewables integration. In this dissertation, a series of systematic approaches are proposed firstly identify the system parameters for more accurate system modeling through PMU measurements, then to assess the system transient stability considering the renewable energy sources operation limits, and finally to adaptively adjust these operation limit for improving the system voltage security. The operation limits are transferred into the form in terms of system states. Linearization and approximation methods are also introduced to enhance the scalability of the processes. Multiple test cases are studied with the proposed approaches and the results demonstrate their effectiveness and efficiency.

The use of Response to Intervention, more commonly referred to as RTI has become more prevalent as school systems look to find ways of bridging the opportunity gap and provide support those students who are not successful in their attempts to access the general education curriculum. More research is needed in order to have a better understanding of not only how schools implement RTI, but also how they utilize data, monitor student progress and help to ensure fidelity of implementation. The purpose of this study was to examine and explain how one elementary school with a high quality RTI program implemented Response to Intervention while keeping all three essential components in consideration. The findings demonstrate that the subject elementary school combined several elements of Response to Intervention and in turn, created their own version of a hybrid RTI model that utilized components from both the standard protocol model and the problem-solving model. In order to monitor student progress, universal screeners were utilized several times throughout the year for both reading and math. Reading was also monitored through running records, PALS Quick Checks, Orton Gillingham assessments, and exit tickets, whereas Math utilized formative assessments, anecdotal notes, and exit tickets to track student progress. Each math and reading CLT met weekly to engage in dialogue around student data. An important finding is that the subject elementary school made RTI implementation decisions around what was best for their students, which allowed for a more flexible and adaptable approach. The system utilized targeted individual student needs and helped to ensure that ALL students had access to the necessary supports that would help to ensure student success. / Doctor of Education / As schools continue to face increasing demands, including how to meet the needs of students with diverse academic backgrounds, they have been charged with exploring new ways and methods of ensuring that students are successful in their attempts to access the general education curriculum. Response to Intervention, more commonly referred to as RTI, has become more widely used in school systems as they continue to work to ensure student success for all. RTI is seen as a tool to help accurately identify students who have a learning disability (Ciolfi and Ryan, 2011), however more research is needed in order to have a better understanding of how schools implement RTI, as well as how they utilize the data collected and monitor student progress. This qualitative case study analyzes how one subject elementary school implemented RTI, how they utilized data, as well as how they monitored the progress of their students.

Dans cette thèse nous adressons le problème de commande des véhicules marins sous-actionnés. La motivation clé de ce sujet de recherche vient du fait qui les systèmes sous-actionnés posent des défis aussi bien théoriques et pratiques pour l'ingénieur automaticien. En fait, ces systèmes ne peuvent pas être stabilisés par des commandes lisses invariantes dans le temps. De plus, en dépit du nombre de méthodes disponibles pour la commande des systèmes mécaniques sous-actionnés, peu ont adressé des points pratiques importantes tels que l'inclusion explicite de dynamique dans la formulation de problème de commande et le besoin de faire face aux perturbations environnementales résultants des courants des vagues, par exemple. Cette thèse attaque certains de ces problèmes, formule et résout les problèmes de commande de positionnement dynamique, de la poursuite de trajectoire et du suivie de chemin des véhicules marins sous-actionnés. La première partie de cette thèse (Chapitres 3 et 4) constituent les éléments théoriques fondamentaux pour l'analyse du modèle et la synthèse des commandes pour les véhicules marins sous-actionnés. Particulièrement, nous montrons au chapitre 3 que le modèle de véhicule marin sous-actionné ne satisfait pas la condition de nécessaire Brockett pour la stabilisation des systèmes nonlinéaires par actions continues et invariantes dans le temps. Cependant, Il sera montré qu'il est possible d'atteindre la stabilisation en utilisant une commande discontinue ou variable dans le temps. Le chapitre 4 consiste à appliquer des résultats récents sur les systèmes cascades nonlinéaires pour résoudre le problème de déterminer des lois de commande qui stabilisent à l'origine la position et l'orientation d vaisseau sous-actionnés. Deux transformations sont introduites pour représenter le système dans une forme de cascade. Par quelques propriétés du modèle, nous montrons en premier que la stabilisation globale et asymptotique du système se réduit a stabiliser une forme en chaîne de troisième ordre. Une approche discontinue par backstepping est ensuite employée pour la stabilisation du système de forme en chaîne via un retour d'état partiel. Nous montrons que la loi de commande proposée stabilise exponentiellement le modèle réduit dans un ensemble défini, assurant le stabilisation asymptotique, local et uniforme du modèle de vaisseau marin sous-actionné. Pour assurer la stabilité uniforme globale cependant, un backstepping et le temps combinés variant l'approche de contrôle est donc employée. Prochain, nous exploitons la structure de cascade pour construire une trajectoire convenable produite par les équations dynamiques d'un véritable sous-actionnés bateau. Nous montrons ensuite que la stabilisation globale peut être assurée par une par une combinaison de la commande par backstepping et une commande variable dans le temps. Ensuite nous abordons le problème de poursuite de trajectoire. Dans lequel la trajectoire de référence est générée par un navire sous-actionné virtuel. Nous montrons ensuite qu'il existe une commande qui force exponentiellement le navire à la poursuite de la trajectoire partant d'une condition initiale quelconque. Utilisant une approche des Systems cascades, nous montrons que la dynamique de l'erreur de poursuite peut être vue comme une cascade d'un système linéaire et d'un système en chaine de deuxième ordre. La deuxième partie de cette thèse (Chapitre 5, 6 et 7) est consacrée au problème de la manoeuvre du vaisseau sous-actionné le long d'un chemin désiré avec une dynamique prescrite. La conception de la loi de commande est abordée par deux approches. La première vient d'une observation qu'il est plausible en pratique de manoeuvrer le véhicule tel qu'il soit sur son chemin de référence est que sa vitesse totale soit tangente au chemin. Il sera aussi supposé que le véhicule voyage le long du chemin avec une vitesse directe constante. La seconde approche ne conditionne pas la vitesse directe pour être constante. Dans le Chapitre 5, nous exploitons l'approche abordée pour le suivi de chemin pour résoudre le problème de coordinations d'un groupe de véhicules marins. Il est objet de manoeuvrer le mouvement de chaque véhicule tel que le mouvement du groupe est prescrit par un comportement désiré. Ainsi, le mouvement indépendant est coordonné comme une formation selon le comportement désirée. Dans ce chapitre nous considérerons le problème de formation ou plusieurs véhicules sont synchronisés de manière qu'ils soient commandés comme une formation de structure virtuelle. Le chapitre 6, est dévouée au problème général de la commande par retour de sortie pour la stabilisation globale des véhicules marins sous-actionnés. Une application de tel observateur est ensuite faite au problème de la poursuite de trajectoire d'un vaisseau sous-actionné.