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Many animal species are known for their unparalleled abilities to encode sensory information that supports fast, reliable action in complex environments, but the mechanisms remain often unclear. Through fast ear motions, bats can encode information on target direction into time-frequency Doppler signatures. These species were thought to be evolutionarily tuned to Doppler shifts generated by a prey's wing beat. Self-generated Doppler shifts from the bat's own flight motion were for the most part considered a nuisance that the bats compensate for. My findings indicate that these Doppler-based biosonar systems may be more complicated than previously thought because the animals can actively inject Doppler shifts into their input signals. The work in this dissertation presents a novel nonlinear principle for sensory information encoding in bats. Up to now, sound-direction finding has required either multiple signal frequencies or multiple pressure receivers. Inspired by bat species that add Doppler shifts to their biosonar echoes through fast ear motions, I present a source-direction finding paradigm based on a single frequency and a single pressure receiver. Non-rigid ear motions produce complex Doppler signatures that depend on source direction but are difficult to interpret. To demonstrate that deep learning can solve this problem, I have combined a soft-robotic microphone baffle that mimics a deforming bat ear with a CNN for regression. With this integrated cyber-physical setup, I have able to achieve a direction-finding accuracy of 1 degree based on a single baffle motion. / Doctor of Philosophy / Bats are well-known for their intricate biosonar system that allow the animals to navigate even the most complex natural environments. While the mechanism behind most of these abilities remains unknown, an interesting observation is that some bat species produce fast movements of their ears when actively exploring their surroundings. By moving their pinna, the bats create a time-variant reception characteristic and very little research has been directed at exploring the potential benefits of such behavior so far. One hypothesis is that the speed of the pinna motions modulates the received biosonar echoes with Doppler-shift patterns that could convey sensory information that is useful for navigation. This dissertation intends to explore this hypothetical dynamic sensing mechanism by building a soft-robotic biomimetic receiver to replicate the dynamics of the bat pinna. The experiments with this biomimetic pinna robot demonstrate that the non-rigid ear motions produce Doppler signatures that contain information about the direction of a sound source. However, these patterns are difficult to interpret because of their complexity. By combining the soft-robotic pinna with a convolutional neural network for processing the Doppler signatures in the time-frequency domain, I have been able to accurately estimate the source direction with an error margin of less than one degree. This working system, composed of a soft-robotic biomimetic ear integrated with a deep neural net, demonstrates that the use of Doppler signatures as a source of sensory information is a viable hypothesis for explaining the sensory skills of bats.

We constrain the proper motions of five OB stars associated with candidate stellar wind bow shocks in the Carina Nebula using Hubble Space Telescope ACS imaging over 9-10 yr baselines. These proper motions allow us to directly compare each star's motion to the orientation of its candidate bow shock. Although these stars are saturated in our imaging, we assess their motion by the shifts required to minimize residuals in their airy rings. The results limit the direction of each star's motion to sectors less than 90 degrees wide. None of the five stars are moving away from the Carina Nebula's central clusters as runaway stars would be, confirming that a candidate bow shock is not necessarily indicative of a runaway star. Two of the five stars are moving tangentially relative to the orientation of their candidate bow shocks, both of which point at the OB cluster Trumpler 14. In these cases, the large-scale flow of the interstellar medium, powered by feedback from the cluster, appears to dominate over the motion of the star in producing the observed candidate bow shock. The remaining three stars all have some component of motion towards the central clusters, meaning that we cannot distinguish whether their candidate bow shocks are indicators of stellar motion, of the flow of ambient gas or of density gradients in their surroundings. In addition, these stars' lack of outward motion hints that the distributed massive-star population in Carina's South Pillars region formed in place, rather than migrating out from the association's central clusters.

Ground motions caused by earthquakes may be strong enough to cause destruction of infrastructure and possibly casualties. If such past destructive earthquakes are analysed, the gained information could be used to develop earthquake warning systems that predicts and possibly reduce the damage potential of further earthquakes. The Swedish National Seismic Network (SNSN) runs an automated early warning system that attempts to predict the damage of an earthquake that just got recorded, and forward the predictions to relevant government agencies. The predictions are based on, e.g. earthquake magnitude, source depth and an estimate of the size of affected human population. The purpose of this thesis is to introduce an additional parameter: earthquake intensity, which is a measure of the intensity with which the ground shakes. Based on this, a new earthquake hazard scheme, the Intensity Based Earthquake Classification (IBEC) scheme, is created. This scheme suggests alternate methods, relative to SNSN, of how earthquake classifications can be made. These methods will use an intensity database established by modelling scenario earthquakes in the open-source software ShakeMap by the U.S. Geological Survey. The database consists of scenarios on the intervals: 4.0 ≤ Mw ≤ 9.0 and 10 ≤ depth ≤ 150 kilometre, and covers the whole intensity scale, Modified Mercalli Intensity, 1.0 ≤ Imm ≤ 10.0. The IBEC classification scheme also enabled the creation of the 'Population-to-Area' criterion. It improves prediction of earthquakes that struck isolated cities, located in e.g. valleys in large mountainous areas and deserts. Even though such earthquakes are relatively uncommon, once they occur, they may cause great damage as many cities in such regions around the world often are less developed regarding resistance to ground motions. / Markrörelser orsakade av jordbävningar kan va starka nog att skada vår infrastruktur och orsaka dödsoffer. Genom att analysera forna destruktiva jordbävningar och utveckla program som försöker att förutsäga deras inverkan så kan den potentiella skada minskas. Svenska Nationella Seismiska Nätet (SNSN) driver ett automatiserat tidigt varningssystem som försöker förutsäga skadorna som följer en jordbävning som precis spelats in, och vidarebefodra denna information till relevanta myndigheter. Förutsägelserna är baserade på, t.ex. jordbävnings-magnitud och djup samt uppskattning av mänsklig population i det påverkade området. Syftet med denna avhandlingen är att introducera ytterligare en parameter: jordbävnings-intensitet, som är ett mått av intensiteten i markrörelserna. Baserat på detta skapas ett jordbävnings-schema kallat Intensity Based Earthquake Classification (IBEC). Detta schema föreslår alternativa metoder, relativt SNSN, för hur jordbävnings-klassificering kan göras. Dessa metoder använder sig av en intensitets-databas etablerad genom modellering av jordbävning-scenarios i open source-\linebreak programmet ShakeMap, skapat av U.S. Geological Survey. Databasen består av scenarior över intervallen 4.0 ≤ Mw ≤ 9.0 och 10 ≤ djup ≤ 150 kilometer, vilka täcker hela intensitetsskalan, Modified Mercalli Intensity, 1.0 ≤ Imm ≤ 10.0. IBECs klassificeringsschema har även möjliggjort skapandet av "Population-mot-Area"-kriteriet. Detta förbättrar förutsägelsen av jordbävningar som träffar isolerade städer, placerade i t.ex. dalgångar i stora bergskjedjor och öknar. Även om denna typ av jordbävningar är relativt ovanliga så orsakar dom ofta enorm skada då sådana här städer ofta är mindre utvecklade rörande byggnaders motstånd mot markrörelser.

A recently developed approach, in the area of nonlinear oscillations, is used to analyze the single degree of freedom equation of motion of a oating unit (such as a ship) about a critical axis (such as roll). This method makes use of a closed form analytic solution, exact upto the rst order, and takes into account the the complete unperturbed (no damping or forcing) dynamics. Using this method very-large-amplitude nonlinear vessel motion in a random seaway can be analysed with techniques similar to those used to analyse nonlinear vessel motions in a regular (periodic) or random seaway. The practical result being that dynamic capsizing studies can be undertaken considering the shortterm irregularity of the design seaway. The capsize risk associated with operation in a given sea state can be evaluated during the design stage or when an operating area change is being considered. Moreover, this technique can also be used to guide physical model tests or computer simulation studies to focus on critical vessel and environmental conditions which may result in dangerously large motion amplitudes. Extensive comparitive results are included to demonstrate the practical usefulness of this approach. The results are in the form of solution orbits which lie in the stable or unstable manifolds and are then projected onto the phase plane.

L’effet de Conditionnement Evaluatif (CE) correspond au changement de valence émotionnelle d’un stimulus initialement neutre (Stimulus Conditionnel, SC), suite à son association avec un stimulus affectif (Stimulus Inconditionnel, SI). Dans cette thèse, nous abordons le sujet du CE avec une approche fonctionnelle en trois axes. Après une présentation générale de l’effet de CE, nous proposons, dans chacun des axes, la description et l’opérationnalisation de nouvelles procédures expérimentales pour chacune des étapes typiques d’une expérience de CE (Apprentissage, Mesure et Modification).Dans l’axe 1, nous proposons une nouvelle procédure d’apprentissage, utilisant des mouvements en tant que stimuli affectifs. L’axe 2 porte sur la mesure de l’effet de CE, nous y présentons la Semi Implicit Task (SIT) destinée à évaluer l’attitude envers un stimulus. Enfin, l’axe 3 s’intéresse à la modification de l’effet de CE, nous présentons des méthodologies destinées à modifier les affects acquis par des stimuli, avec et sans recours à des interventions verbales.Tout au long de ce travail, pour chacune des méthodologies proposées, les implications théoriques et les applications pratiques, particulièrement en psychothérapie, sont discutées. Dans la dernière partie de cette thèse, nous partageons différentes réflexions théoriques relatives à la fonction et la conceptualisation de l’effet de CE, et présentons quelques perspectives de recherches cliniques. / Evaluative Conditioning (EC) is a change in liking of a neutral stimulus (conditioned stimulus, CS) resulting from its association with an emotional stimulus (Unconditioned stimulus, US). In the present thesis we investigate EC using a functional approach. After a general presentation of EC, we focus on both describing and operationalizating new experimental procedures corresponding to each typical phase of an EC experiment: Learning, Measurement and Modification.First, we describe a new learning procedure using motion as USs. Second, we investigate a new measure of EC that we have called the Semi Implicit Task that assess attitude toward CSs. Finally, we investigate the modification of acquired valences with methodologies based on interventions with and without the use of verbal information.Within this general perspective, we discuss both theoretical implications and practical applications of EC. Regarding the second point, we shed light on potential applications in the domain of clinical psychology.

Made available in DSpace on 2016-12-23T14:08:15Z (GMT). No. of bitstreams: 1 Jose Guilherme Pelicao Pancieri.pdf: 849076 bytes, checksum: 4cc56d57d53f4b6c3d0fd9c325a5bd22 (MD5) Previous issue date: 2012-03-27 / O presente trabalho apresenta a modelagem matemática de um sistema vibracional com excitação harmônica da base. Esse tipo de sistema tem sido estudado por vários pesquisadores que exploraram muitos aspectos da dinâmica global. No entanto, na grande parte dos sistemas estudados, o sistema era modelado para uma característica de vibroimpacto. No sistema aqui estudado, os impactos são substituídos por outro conjunto visco-elástico e os instantes de transição são considerados como condição de periodicidade. As condições de periodicidade são aplicadas sobre o estado nos instantes de transição a fim de obter um mapa da próxima transição baseada no estado da anterior. Este mapa não-linear é aplicado para obter as condições de existência dos movimentos periódicos com padrões específicos. Assim, aplicando as condições de existência, a estabilidade do movimento pode ser realizada por meio da análise dos autovalores do mapa linearizado, tendo em conta estas restrições / This work presents the mathematical modeling of a vibrational system with the harmonically excited base. The system has been investigated by several researchers exploring many aspects of the global dynamics. However, in most of the systems studied, the systems were modeled for a vibro-impact feature. In this system, the impacts are replaced by another visco-elastic set and the moment of transition is considered as a condition of periodicity. Periodicity conditions are applied on the state at the moment of transition in order to obtain a map of the next transition based on the state of the previous one. This nonlinear map is used to obtain the conditions of existence of periodic motions with specific patterns. Applying the existence conditions, the stability of the motion can be achieved by analyzing the eigenvalues of the linearized map while taking these conditions into account

We generalize the notions of structural stability and hyperbolicity for the family of (multivalued) complex maps Hc(z) = zr + c; where r > 1 is rational and zr = exp r log z: We discovered that Hc is structurally stable at every hyperbolic parameter satisfying the escaping condition. Surprisingly, there may be infinitely many attracting periodic points for Hc. The set of such points gives rise to the dual Julia set, which is a Cantor set coming from a Conformal Iterated Funcion System. Both the Julia set and its dual are projections of holomorphic motions of dynamical systems (single valued maps) defined on compact subsets of Banach spaces, denoted by Xc and Wc, respectively. For c close to zero: (1) we show that Jc is a union of quasiconformal arcs around the unit circle; (2) the set Xc is an holomorphic motion of the solenoid X0; (3) using the formalism of Gibbs states we exhibit an upper bound for the Hausdorff dimension of Jc; which implies that Jc has zero Lebesgue measure. / Generalizamos as noções de estabilidade estrutural e hiperbolicidade para a família de correspondências holomorfas Hc(z) = zr + c; onde r > 1 é racional e zr = exp r log z: Descobrimos que Hc é estruturalmente estável em todos os parâmetros hiperbólicos satisfazendo a condição de fuga. Tipicamente Hc possui infinitos pontos periódicos atratores, fato totalmente inesperado, uma vez que este número é sempre finito para aplicações racionais. O conjunto de tais pontos dá origem ao chamado conjunto de Julia dual, que é um conjunto de Cantor proveniente de um Conformal Iterated Function System. Tanto o conjunto de Julia e quanto seu dual são projeções de movimentos holomorfos de sistemas definidos em subconjuntos compactos denotados por Xc e Wc; respectivamente de um espaço de Banach. Para todo c próximo de zero: (1) mostramos que Jc é reunião de arcos quase-conformes próximos do círculo unitário; (2) o conjunto Xc é um movimento holomorfo do solenóide X0; (3) utilizando o formalismo dos estados de Gibbs, exibimos um limitante superior para a dimensão de Hausdorff de Jc. Consequentemente, Jc possui medida de Lebesgue nula.

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Liquid sloshing in a 2D tank applied on a wave energy capture system and reducing the oscillation of an offshore platform are discussed in this study. A fully nonlinear time-independent finite difference method and the forth-order Runge-Kutta method are implemented to solve the coupled motions of liquid sloshing in a 2D tank with a floating platform. When the external forcing frequency of the Dynamic Vibration Absorber System composed by a tuned liquid damper and a tuned mass damper is identical to the fundamental frequency of the tank, the external force can be effectively diminished by the sloshing-induced force. In the meantime, the maximum effect of tuned mass damper on reducing the amplitude of the floating platform appears. When the frequency of external forcing is close to the first natural frequency of the liquid tank, the coupled effect between the motions of both the tank and the platform can effectively reduce the vibration of the platform and the total energy of the whole system. The Eigenfrequency of a wave capture system is formed by the coupled effect of a liquid tank and a wave capture system. When the excitation frequency of the wave capture system is near its Eigenfrequency, the sloshing-induced force is much larger than that of external and the maximum displacement of the wave energy capture system occurs. As a result, the wave energy capacity of the wave capture system can be averagely increased to 150% by the influence of liquid sloshing in the tank.