The control of complex robotic platforms is a challenging task, especially in designs with high levels of kinematic redundancy. Novel variable impedance actuators (VIAs) have recently demonstrated that, by allowing the ability to simultaneously modulate the output torque and impedance, one can achieve energetically more efficient and safer behaviour. However, this adds further levels of actuation redundancy, making planning and control of such systems even more complicated. VIAs are designed with the ability to mechanically modulate impedance during movement. Recent work from our group, employing the optimal control (OC) formulation to generate impedance policies, has shown the potential benefit of VIAs in tasks requiring energy storage, natural dynamic exploitation and robustness against perturbation. These approaches were, however, restricted to systems with smooth, continuous dynamics, performing tasks over a predefined time horizon. When considering tasks involving multiple phases of movement, including switching dynamics with discrete state transitions (resulting from interactions with the environment), traditional approaches such as independent phase optimisation would result in a potentially suboptimal behaviour. Our work addresses these issues by extending the OC formulation to a multiphase scenario and incorporating temporal optimisation capabilities (for robotic systems with VIAs). Given a predefined switching sequence, the developed methodology computes the optimal torque and impedance profile, alongside the optimal switching times and total movement duration. The resultant solution minimises the control effort by exploiting the actuation redundancy and modulating the natural dynamics of the system to match those of the desired movement. We use a monopod hopper and a brachiation system in numerical simulations and a hardware implementation of the latter to demonstrate the effectiveness and robustness of our approach on a variety of dynamic tasks. The performance of model-based control relies on the accuracy of the dynamics model. This can deteriorate significantly due to elements that cannot be fully captured by analytic dynamics functions and/or due to changes in the dynamics. To circumvent these issues, we improve the performance of the developed framework by incorporating an adaptive learning algorithm. This performs continuous data-driven adjustments to the dynamics model while re-planning optimal policies that reflect this adaptation. The results presented show that the augmented approach is able to handle a range of model discrepancies, in both simulation and hardware experiments using the developed robotic brachiation system.

Submitted by Marina Gonzaga de Oliveira (marina_oliveiira@hotmail.com) on 2018-06-13T18:44:25Z No. of bitstreams: 1 Dissertação - Marina Gonzaga de Oliveira.pdf: 2620902 bytes, checksum: 459ac9bfc6bdcf9d2b46699b0031a626 (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-06-13T19:49:28Z (GMT) No. of bitstreams: 1 oliveira_mg_me_rcla.pdf: 2620902 bytes, checksum: 459ac9bfc6bdcf9d2b46699b0031a626 (MD5) / Made available in DSpace on 2018-06-13T19:49:28Z (GMT). No. of bitstreams: 1 oliveira_mg_me_rcla.pdf: 2620902 bytes, checksum: 459ac9bfc6bdcf9d2b46699b0031a626 (MD5) Previous issue date: 2018-06-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / É quase um consenso que os planetas ao serem formados, nasceram com obliquidades quase nulas. No entanto, para os planetas gigantes, exceto Júpiter, as atuais obliquidades estão longe de zero. Para Saturno, Urano e Netuno elas são, respectivamente, 25,61°, 97,86°, 28,31°. Em geral, as razões que alteraram as obliquidades estão associadas a efeitos gravitacionais como colisões ou capturas em ressonâncias. Neste trabalho pretendemos montar o sistema médio que governa a dinâmica de longo período da variação da obliquidade de um planeta considerando o Sol e um satélite com massas e distâncias diversas. Usaremos variáveis de Andoyer pois, por serem canônicas, as médias podem ser realizadas de forma rigorosa sempre que feitas em variáveis ação - ângulo. A questão do “wooble” pode ser facilmente incorporada se necessário. Pretendemos com este modelo estudar a variação da obliquidade de Netuno, mas em princípio pode ser usado também nos casos de exoplanetas (ARMSTRONG et al., 2014). O planeta Netuno, aparentemente é o único que não tem nenhum satélite regular primordial, ao contrário dos demais. Boué e Laskar (2010) fizeram uso de um satélite adicional para explicar a obliquidade de Urano. Porém, a presença de um satélite adicional de massa muito elevada, poderia desestabilizar os primordiais já existentes. No caso de Netuno, as massas dos satélites adicionais que pretendemos usar podem ser muito menores do que aquelas usadas por Boué e Laskar, o que elimina de vez, possível desestabilização de eventuais satélites primordiais regulares, caso eles tenham existido. / It is almost a consensus that the planets, when formed, were born with almost zero obliquities. However, for giant planets except Jupiter, the current obliquities ( ) are far from zero. For Saturn, Uranus, and Neptune they are, respectively, 25 . 6 ◦ , 97 . 8 ◦ , 28 . 3 ◦ . In general, the reasons that changed the obliquities are associated to gravitational effects such as collisions or captures in resonances. In this work we intend to build the average system that governs the long period dynamics of the variation of the obliquity of a planet considering the Sun and a satellite with different masses and distances. We will use Andoyer variables, because they are canonical, so averages can be performed rigorously whenever they are made in angle-action variables. The “wooble” issue can be easily incorporated if necessary. We intend with this model to study the variation of the Neptune’s obliquity, but in principle it can also be used in the case of exoplanets (ARMSTRONG et al., 2014). The planet Neptune, apparently is the only one that has no regular primordial satellite, unlike the others. Boué e Laskar (2010), used an additional satellite to explain the Uranus’ obliquity. However, the presence of an additional satellite with very high mass could destabilize the existing primordial ones. In the case of Neptune, the masses of the additional satellites that we intend to use may be much smaller than those used by Boué and Laskar, which eliminates possible destabilization of eventual regular primordial satellites, if they existed. / FAPESP: 2016/07046-4.

This thesis includes multinominals with one{\crq}s variables. Aim is create collection exercises hereto subject. Collection is divided on chaps with given to problems. In every chapter is totality theory buckthorn examples and straddle examples. All choice example are exemplary processed. Behind every chapter reader can try out problems for examles that are supplementeds record

The importance of the Stokes system stems from the fact that the Stokes system is the stationary linearised form of the Navier Stokes system [Te01, Chapter1]. This linearisation is allowed when neglecting the inertial terms at a low Reinolds numbers Re << 1. The Stokes system essentially models the behaviour of a non - turbulent viscous fluid. The mixed interior boundary value problem related to the compressible Stokes system is reduced to two different BDIES which are equivalent to the original boundary value problem. These boundary-domain integral equation systems (BDIES) can be expressed in terms of surface and volume parametrix-based potential type operators whose properties are also analysed in appropriate Sobolev spaces. The invertibility and Fredholm properties related to the matrix operators that de ne the BDIES are also presented. Furthermore, we also consider the mixed compressible Stokes system with variable viscosity in unbounded domains. An analysis of the similarities and differences with regards to the bounded domain case is presented. Furthermore, we outline the mapping properties of the surface and volume parametrix-based potentials in weighted Sobolev spaces. Equivalence and invertibility results still hold under certain decay conditions on the variable coeffi cient The last part of the thesis refers to the mixed boundary value problem for the stationary heat transfer partial di erential equation with variable coe cient. This BVP is reduced to a system of direct segregated parametrix-based Boundary-Domain Integral Equations (BDIEs). We use a parametrix different from the one employed by Chkadua, Mikhailov and Natroshvili in the paper [CMN09]. Mapping properties of the potential type integral operators appearing in these equations are presented in appropriate Sobolev spaces. We prove the equivalence between the original BVP and the corresponding BDIE system. The invertibility and Fredholm properties of the boundary-domain integral operators are also analysed in both bounded and unbounded domains.

Orientador: Tania Maria Alkmim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-03T21:46:52Z (GMT). No. of bitstreams: 1 Tomanin_CassiaRegina_M.pdf: 505569 bytes, checksum: 07a4b3053b698ae7cdc2e687b2e1ae57 (MD5) Previous issue date: 2004 / Resumo: Esta pesquisa tem como objetivo principal a descrição da fala de Alto Araguaia, pequeno município do interior mato-grossense situado na divisa com o Estado de Goiás. Tal município tem recebido, desde sua fundação até os dias atuais, migrantes das mais diversas regiões do país. A constituição heterogênea da população araguaiense provoca na comunidade o surgimento de uma variedade lingüística que apresenta traços fonéticos e gramaticais de várias regiões do país. Um outro ponto objetivado aqui é a comparação dos fenômenos registrados na fala de Alto Araguaia com os que ocorrem em outras localidades brasileiras, com o intuito de que seja observada a semelhança/diferença entre as diferentes comunidades. A maioria dos fenômenos lingüísticos aqui apresentados, tanto os de natureza fonética quanto os de natureza morfológica ou sintática encontramse em variação. Grande parte daqueles que são produzidos de forma sistemática ocorre, de forma variável ou sistemática, praticamente em todo o território nacional. Foi verificado ainda que o fator externo origem não se mostra influente na fala araguaiense, ou seja, os traços lingüísticos de regiões como o nordeste e o sul estão dissolvidos na fala local. O principal fator externo que pode ser responsabilizado pela variação é a escolaridade, que influencia tanto na produção de fenômenos fonéticos quanto gramaticais / Abstract: This research has as main objective the description of the speech in Alto do Araguaia, a small municipal district in Mato Grosso State, located in the border with the State of Goiás. Such municipal district has been receiving since its fundations to the current days, migrants from several areas odf the country. The heterogeneouns constituition of the population provokes in the comunity the emergence of linguistic variety that that presents phonectics and grammatical feature of several areas of the country. Another poin aimed here is the comparison of registred phenomena in the speech of Alto Araguaia with the ones that happen at other Brazilian places, with the intention in observe similarity/difference among the different communities. Most of the linguitic phenomena here presented, as much as phonetics nature, as morphologie nature or syntactic nature are in variation. Most of those that are produced in a systmatic way happens, in a variable or systematic way practically in the whole national territory. It was verified yet that the external origin factor is not shown influential in the araguaiense speech, in other words, the linguistic feature in areas as the northeast and the south are dissolved in the local speech. The main external factor that can be responsable by the variation id the education, that influences as much as in the production of phonetic and grammatical phenomena / Mestrado / Linguistica / Mestre em Linguística

D.Phil. / During the last few years the number of known variable stars which show periodic light level changes has grown by several tens of thousands. The aim of the research reported here was to extend the suite of statistical methods available for the analysis of periodic variable star time series. Solution techniques for five problems are discussed. The first is an automated method for detecting periodic variable stars from a database containing of the order of 100 000 time series of observations. Typically only 100-200 brightness measurements of each star were obtained, spread irregularly over an interval of about 3 years. The proposed method is based on a signal to noise ratio. Percentiles for the statistic are found by studying randomisations of a large number of the observed time series. It is shown that the percentiles depend strongly on the number of observations in a given dataset, and the dependence is calibrated empirically. The estimation of the frequency, amplitude and phase of a sinusoid from observations contaminated by correlated noise is the second problem considered. The study of the observational noise properties of nearly 200 real datasets of the relevant type is reported: noise can almost always be characterised as a random walk with superposed white noise. A scheme for obtaining weighted nonlinear least squares estimates of the parameters of interest, as well as standard errors of these estimates, is described. Simulation results are presented for both complete and incomplete data, and an application to real observations is also shown. In the third topic discussed it is assumed that contemporaneous measurements of the light in-tensity of a pulsating star is obtained in several colours. There is strong theoretical interest in a comparison of the amplitudes and phases of the variations in the different colours. A general scheme for calculating the covariance matrix of the estimated amplitude ratios and phase differences is described. The first step is to fit a time series model to the residuals after subtracting the best-fitting sinusoid from the observations. The residuals are then crosscorrelated to study the interdependence between the errors in the different colours. Once the multivariate time series structure can be modelled, the covariance matrix can be found by bootstrapping. An illustrative application is described in detail. The times between successive instances of maximum brightness, or the times between successive brightness minima, serve as estimates for the periods of the so-called "long period variables" (stars with pulsation periods of the order of months). The times between successive maxima (or minima) vary stochastically, and are also subject to measurement errors, which poses a problem for tests for systematic period changes — the topic of the fourth problem studied. A simple statistical model for the times between successive maxima, or minima, of such stars is used to calculate the auto-correlation properties of a new time series, which is non-stationary in its variance. The new series consists of an alternation of cycle lengths based on respectively the times between maxima, and those between minima of the light curve. Two different approaches to calculating the theoretical spectrum of the non-stationary time series, as required in the proposed statistical hypothesis test, are given. Illustrative applications complete the relevant chapter.

Genetic regulatory networks are of great importance in terms of scientific interests and practical medical importance. Since a number of high-throughput measurement devices are available, such as microarrays and sequencing techniques, regulatory networks have been intensively studied over the last decade. Based on these high-throughput data sets, statistical interpretations of these billions of bits are crucial for biologist to extract meaningful results. In this thesis, we compare a variety of existing regression models and apply them to construct regulatory networks which span trancription factors and microRNAs. We also propose an extended algorithm to address the local optimum issue in finding the Maximum A Posterjorj estimator. An E. coli mRNA expression microarray data set with known bona fide interactions is used to evaluate our models and we show that our regression networks with a properly chosen prior can perform comparably to the state-of-the-art regulatory network construction algorithm. Finally, we apply our models on a p53-related data set, NCI-60 data. By further incorporating available prior structural information from sequencing data, we identify several significantly enriched interactions with cell proliferation function. In both of the two data sets, we select specific examples to show that many regulatory interactions can be confirmed by previous studies or functional enrichment analysis. Through comparing statistical models, we conclude from the project that combining different models with over-representation analysis and prior structural information can improve the quality of prediction and facilitate biological interpretation. Keywords: regulatory network, variable selection, penalized maximum likelihood estimation, optimization, functional enrichment analysis. / Science, Faculty of / Graduate

Durant les trois années de la thèse, j’ai eu le plaisir de travailler en collaboration avec à la fois des volcanologues, des physiciens de laboratoire et des mathématiciens. Ce mémoire est l’occasion de présenter la démarche et les résultats de mes recherches dans le domaine de la modélisation d’écoulements granulaires denses fluidisés. Ces derniers consistent à développer un nouveau modèle mathématique et son étude théorique et numérique. Sur la base d’observations faites lors d’expériences de laboratoire, nous proposons une façon de modéliser le changement comportemental d’un écoulement granulaire initialement fluidisé au travers de la définition de sa rhéologie viscoplastique à seuil variable. Plus précisément, le seuil de plasticité est défini par la différence entre la pression lithostatique et la pression du fluide interstitiel. La nouveauté apportée par ce modèle ouvre de nouvelles perspectives à la fois pour le champ de recherche en mathématiques et pour la compréhension des lits granulaires fluidisés et leur application à la volcanologie. Du point de vue mathématique, une étude théorique du modèle a été menée. En proposant une preuve de l’existence de solutions faibles à un problème lié à la version homogène du modèle, nous apportons une extension au champ de connaissances autour des écoulements des fluides non-newtoniens. D’autre part, dans le but de reproduire numériquement des expériences de laboratoire de chute de colonne granulaire fluidisée, nous avons développé un code de simulation numérique incluant une nouvelle méthode de résolution des équations d’écoulement de fluides à seuil. Dans ce manuscrit, je décris et justifie les différents choix stratégiques pour le développement de ce code. Par ailleurs, je présente quelques tests académiques permettant de valider le code. Enfin, je donne les résultats de simulation de chute de colonne granulaire, qu’elle soit fluidisée ou non. Une comparaison avec les données de laboratoire est effectuée afin d’évaluer les points forts et les défauts du modèle par rapport à la réalité des expériences. En conclusion, dans la continuité du travail mené dans ce projet, des perspectives d’amélioration sont proposées. / During these three years, I enjoyed to work with collaborators from volcanology, laboratory physics and mathematics. This document presents the steps and results of my research in the field of modelling of fluidised granular flows. The last consists in the development of a new mathematical model and its theoretical and numerical study. Based on observations made on experimental studies, the model focuses on the change in the behaviour of an initially fluidised granular flow through the definition of its viscoplastic rheology with variable threshold. More precisely, the threshold (aslo called yield stress) is defined via the difference between the lithostatic pressure and the pressure of the interstitial fluid. The innovation of this model opens perspectives for the mathematical research as well as for the study of fluidised granular flows and their application to volcanology. From a mathematical point of view, a theoretical study has been conducted. Proving the existence of weak solution for the homogeneous version of the model, we offer an extension in the field of knowledges of non-newtonian fluid flows. Also, we have developped a numerical code to simulate dambreak experiments with fluidised granular media. This one includes a new method to solve the flow equations of viscoplastic fluids. In this thesis, I describe and justify the numerical strategy chosen. Moreover, I present some academic tests to validate the code. At the end, I give the numerical results in the case of the dambreak simulation for dry and fluidised fluids. By comparing with experimental data, we evaluate the validity of the model and its resolution, and highlight the advantages and inconvenients. To conclude the project, I propose some perspectives of improvement for later work.

No description available.

Tesis para optar al grado de Magíster en Finanzas / El trabajo tiene el objetivo de cuantificar el impacto de la política económica en los mercados de renta fija y variable. Utilizando el trabajo de Cook y Hahn (1989) como base, utilizando Swaps de tasas de interés, se logra distinguir entre variaciones esperadas e inesperadas de la tasa referencial (TPM), dictada por los Bancos Centrales. Los países tomados en cuenta para la investigación son Chile, Brasil, Colombia, México y Estados Unidos. Los resultados relacionados con el mercado de bonos, indican que en todas las plazas se cumple la relación positiva entre TPM y yield, siendo mayor el efecto en los horizontes cortos. Respecto a la renta variable o índices accionarios, solo se encontraron resultados significativos para Brasil, Chile y Estados Unidos. En estos casos se cumplió la relación negativa entre TPM y precio bursátil, justificada principalmente por el premio por riesgo.