Most engineering structures include nonlinearity to some degree. Depending on the dynamic conditions and level of external forcing, sometimes a linear structure assumption may be justified. However, design requirements of sophisticated structures such as satellites, stabilized weapon systems and radars may require nonlinear behavior to be considered for better performance. Therefore, it is very important to successfully detect, localize and parametrically identify nonlinearity in such cases. In engineering applications, the location of nonlinearity and its type may not be always known in advance. Furthermore, as the structure will be excited from only a few coordinates, the frequency response function matrices will not be complete. In order to parametrically identify more than one type of nonlinearity which may co-exist at the same location with the above mentioned limitations, a method is proposed where restoring force surface plots are used which are evaluated by describing function inversion. Then, by reformulating this method, a second method is proposed which can directly evaluate the total describing function of more than one type of nonlinearity which may co-exist at the same location without using any linear frequency response function matrix. It is also aimed in this study to use the nonlinearity localization formulations for damage localization purposes. The validation of the methods developed in this study is demonstrated with case studies based on simulated experiments, as well as real experiments with nonlinear structures and it is concluded that the methods are very promising to be used in engineering structures.

O objetivo desta pesquisa consiste em analisar através da caracterização química de fases cristalinas a composição e estrutura; e com a caracterização física a densidade, porosidade e área superficial dos seguintes cimentos endodônticos: MTA Fillapex, AH Plus, Sealer 26 e o Endofill. Para tal, foram realizadas análises dos cimentos antes da manipulação (pó e pastas) e depois da manipulação (corpos de prova). Empregando-se as técnicas de caracterização química: DRX e FRX e como técnicas de caracterização física: Picnometria de Hélio, a porosimetria de mercúrio, distribuição granulométrica e área superficial pela metodologia de BET. A caracterização química detalhou a composição dos cimentos sendo compatível com a descrição do fabricante e forneceu a quantificação das suas fases. A caracterização física mostrou que o MTA Fillapex apresentou os melhores resultados: a menor porosidade, o menor volume médio e o menor diâmetro do poro, o Sealer 26 dentre os cimentos resinosos apresentou o pior resultado, o Endofill mostrou-se melhor que o Sealer 26 tendo a maior densidade, o menor diâmetro das partículas, a distribuição granulométrica mais homogênea comparando-se a este. Os cimentos a base de resina mostraram um diâmetro do poro menor que o Endofill. Estes resultados podem estar ligados diretamente aos requisitos de um material obturador ideal. A metodologia utilizada produziu um detalhamento das características químicas e físicas dos cimentos estudados, mostrando um caminho para novas pesquisas na área. / The objective of this research is to examine through characterization chemical composition and crystallographic phase structure and the physical density, porosity and surface area of root canal sealers: MTA Fillapex, AH Plus, Sealer 26 and Endofill. To this end, we performed analysis of cements before handling (powder or paste) and after manipulation (specimens), employing the techniques of chemical characterization: DRX and FRX and physical characterization: Helium Picnometry, mercury porosimetry, granulometric distribution and surface area by BET method. The chemical characterization detailed the composition of the cements being compatible with the description of the manufacturers and provided the quantification of the phases. The physical characterization showed that MTA Fillapex presented the best results: the lowest porosity, the smallest average volume and the smallest pore diameter; Sealer 26 among the resinous cements presented the worst result; Endofill proved to be better than Sealer 26 having the highest density, the smallest diameter of the particles , and homogeneous granulometric distribution equal to it. The resin-based cements showed a pore diameter smaller than Endofill. These results may be connected directly to the requirements of an ideal endodontic filling material. The methodology used outlined the physical and chemical characteristics of the cements studied, laying the ground to new researches in the area.

Orientador: José Luiz Gasche / Resumo: A maioria dos sistemas de refrigeração por compressão de vapor utiliza compressores alternativos, considerados mecanismos importantes na era moderna. O ciclo de operação de um compressor alternativo é descrito por uma série de fenômenos complexos ocorrendo em um curto período de tempo. Dentre os fatores considerados importantes para e ciência termodinâmica dos compressores, destacam-se as válvulas que controlam os processos de sucção e de descarga, que são responsáveis por grandes perdas termodinâmicas no ciclo. Parte das perdas ocorre no sistema de válvulas, particularmente na válvula de sucção, onde as instabilidades do seu movimento reduzem a e ciência do processo de sucção. Como uma forma de reduzir os problemas gerados pelas instabilidades no funcionamento da válvula de sucção, propomos a utilização de um esbarro para limitar a abertura máxima da válvula, reduzindo sua instabilidade e aumentando a e ciência do compressor. Mostramos experimentalmente que existe uma posição de equilíbrio que mantém a válvula aberta sem instabilidades e que esta posição varia, aproximadamente, linearmente com o número de Reynolds. / Mestre

O objetivo desta pesquisa consiste em analisar através da caracterização química de fases cristalinas a composição e estrutura; e com a caracterização física a densidade, porosidade e área superficial dos seguintes cimentos endodônticos: MTA Fillapex, AH Plus, Sealer 26 e o Endofill. Para tal, foram realizadas análises dos cimentos antes da manipulação (pó e pastas) e depois da manipulação (corpos de prova). Empregando-se as técnicas de caracterização química: DRX e FRX e como técnicas de caracterização física: Picnometria de Hélio, a porosimetria de mercúrio, distribuição granulométrica e área superficial pela metodologia de BET. A caracterização química detalhou a composição dos cimentos sendo compatível com a descrição do fabricante e forneceu a quantificação das suas fases. A caracterização física mostrou que o MTA Fillapex apresentou os melhores resultados: a menor porosidade, o menor volume médio e o menor diâmetro do poro, o Sealer 26 dentre os cimentos resinosos apresentou o pior resultado, o Endofill mostrou-se melhor que o Sealer 26 tendo a maior densidade, o menor diâmetro das partículas, a distribuição granulométrica mais homogênea comparando-se a este. Os cimentos a base de resina mostraram um diâmetro do poro menor que o Endofill. Estes resultados podem estar ligados diretamente aos requisitos de um material obturador ideal. A metodologia utilizada produziu um detalhamento das características químicas e físicas dos cimentos estudados, mostrando um caminho para novas pesquisas na área. / The objective of this research is to examine through characterization chemical composition and crystallographic phase structure and the physical density, porosity and surface area of root canal sealers: MTA Fillapex, AH Plus, Sealer 26 and Endofill. To this end, we performed analysis of cements before handling (powder or paste) and after manipulation (specimens), employing the techniques of chemical characterization: DRX and FRX and physical characterization: Helium Picnometry, mercury porosimetry, granulometric distribution and surface area by BET method. The chemical characterization detailed the composition of the cements being compatible with the description of the manufacturers and provided the quantification of the phases. The physical characterization showed that MTA Fillapex presented the best results: the lowest porosity, the smallest average volume and the smallest pore diameter; Sealer 26 among the resinous cements presented the worst result; Endofill proved to be better than Sealer 26 having the highest density, the smallest diameter of the particles , and homogeneous granulometric distribution equal to it. The resin-based cements showed a pore diameter smaller than Endofill. These results may be connected directly to the requirements of an ideal endodontic filling material. The methodology used outlined the physical and chemical characteristics of the cements studied, laying the ground to new researches in the area.

Submitted by Milton César Cavalheiro Júnior null (milton91250@aluno.feis.unesp.br) on 2017-09-19T17:15:20Z No. of bitstreams: 1 Milton Cavalheiro_dissertação.pdf: 3390678 bytes, checksum: e1e260699364a1cffc56693cd85d631c (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-09-20T16:44:30Z (GMT) No. of bitstreams: 1 cavalheirojunior_mc_me_ilha.pdf: 3390678 bytes, checksum: e1e260699364a1cffc56693cd85d631c (MD5) / Made available in DSpace on 2017-09-20T16:44:30Z (GMT). No. of bitstreams: 1 cavalheirojunior_mc_me_ilha.pdf: 3390678 bytes, checksum: e1e260699364a1cffc56693cd85d631c (MD5) Previous issue date: 2017-07-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A maioria dos sistemas de refrigeração por compressão de vapor utiliza compressores alternativos, considerados mecanismos importantes na era moderna. O ciclo de operação de um compressor alternativo é descrito por uma série de fenômenos complexos ocorrendo em um curto período de tempo. Dentre os fatores considerados importantes para e ciência termodinâmica dos compressores, destacam-se as válvulas que controlam os processos de sucção e de descarga, que são responsáveis por grandes perdas termodinâmicas no ciclo. Parte das perdas ocorre no sistema de válvulas, particularmente na válvula de sucção, onde as instabilidades do seu movimento reduzem a e ciência do processo de sucção. Como uma forma de reduzir os problemas gerados pelas instabilidades no funcionamento da válvula de sucção, propomos a utilização de um esbarro para limitar a abertura máxima da válvula, reduzindo sua instabilidade e aumentando a e ciência do compressor. Mostramos experimentalmente que existe uma posição de equilíbrio que mantém a válvula aberta sem instabilidades e que esta posição varia, aproximadamente, linearmente com o número de Reynolds. / Most of the vapor refrigeration systems use reciprocating compressors, which are considered important mechanisms in the modern era. The cycle of operation of a reciprocating compressor is described by a series of complex phenomena ocurring in a short period of time. Among the factors considered important for the thermodynamic efficiency of compressors are the valves that control the suction and discharge processes, which are responsible for large cycle thermodynamic losses. Part of that losses occurs in the valves system, particularly in the suction valve, where the movement instabilities reduce the efficiency of the suction process. In order to reduce the instabilities of the suction valve, we propose the use of a stop to limit the maximum aperture of the valve, reducing its instabilities and increasing the compressor efficiency. We show experimentally that does exist an static equilibrium position in which the valve remains opened without oscillation and that position varies almost linearly through the Reynolds number.

O objetivo deste estudo foi comparar a capacidade de selamento apical de três materiais retrobturadores em dentes submetidos à infiltração microbiana por Enterococcus faecalis. Além de analisar a ocorrência da infiltração microbiana em relação à variável tempo. Para tal, foram utilizados 80 caninos superiores permanentes humanos extraídos, instrumentados com o sistema rotatório ProTaper Universal (MAILLEFER) e obturados pela técnica de compactação lateral, com dois tipos de cimento endodôntico: Endofill (DENTSPLY) e AH Plus (DENTSPLY). A apicetomia foi realizada com a remoção de 3mm do terço apical e o retropreparo confeccionado com pontas ultrasônicas. As amostras foram subdivididas, aleatoriamente, em 6 grupos com 10 dentes cada, e 2 grupos controles. Os materiais utilizados para a retrobturação foram MTA branco (ANGELUS), IBC BioAggregate (INNOVATIVE BIOCERAMIX INC.) e Acroseal (SEPTODONT). Foram confeccionados dispositivos para fixação dos dentes aos tubos Eppendorfs. As amostras foram inoculadas com cepas de E. faecalis e incubadas a 37C, por um período de 90 dias, para análise da presença de turvação do meio Enterococcosel. Para a realização da análise estatística foram utilizados os seguintes testes: Qui-quadrado com Prova Exata de Fisher e Kruskal-Wallis. Os resultados mostraram que todos os grupos nos quais foi realizada a obturação e a posterior retrobturação apresentaram infiltração. Comparando todos os grupos, não houve diferença significativa entre os materiais testados. Em relação apenas aos materiais retrobturadores, o Acroseal obteve a menor infiltração, seguido do MTA branco e do IBC BioAggregate. As amostras obturadas com o cimento Endofill não apresentaram diferença estatística em relação à variável tempo. Porém, nas amostras obturadas com o cimento AH Plus, houve maior ocorrência de infiltração nas amostras retrobturadas com o IBC BioAggregate e menor infiltração nas amostras retrobturadas com Acroseal, com diferença estatisticamente significante ao nível de 10%. / The objective of this study was to compare the apical sealing ability of three root-end filling materials in teeth submitted to the microbial leakage by Enterococcus faecalis. Besides analyzing the occurrence of the microbial leakage in relation to the variable time.For such, 80 canine permanent superior teeth extracted from humans were used, which were instrumented with ProTaper Universal system (MAILLEFER) and filled by the lateral compaction technique, with two types of endodontic sealers: Endofill (DENTSPLY) and AH Plus (DENTSPLY). The apices were resected with the removal of 3mm of the apical third and the root-end cavities prepared with ultrasonic tips. The samples were subdivided, randomly, in 6 groups with 10 teeth each, and 2 control groups. The materials used for the retrofilling were white MTA (ANGELUS), IBC BioAggregate (INNOVATIVE BIOCERAMIX INC.) and Acroseal (SEPTODONT). Devices were made for fixation of the teeth to the Eppendorf tubes. The filling samples were inoculated with strains of E. faecalis and incubated at 37C, for a period of 90 days, for analysis of the presence of turbidity of Enterococcosel medium. For the accomplishment of the statistical analysis the following tests were used: Qui-square with Exact Proof of Fisher and Kruskal-Wallis. The results showed that all the groups in which the filling was accomplished and the subsequent retrofilling presented leakage. Comparing all groups, there was not significant difference among the tested materials. In regard to only the root-end filling materials, Acroseal obtained the smallest leakage, followed by white MTA and IBC BioAggregate. The samples filled with the sealer Endofill didn't present statistical difference in relation to the variable time. However, in the samples filled with the sealer AH Plus, there was larger leakage occurrence in the samples retrofilled with IBC BioAggregate and smaller leakage in the samples retrofilled with Acroseal, with statistically significant difference at a 10% level.

Ce manuscrit a pour objectif de présenter plusieurs résultats de restauration d’unicité et de sélection d’équilibres dans les jeux à champ moyen. La théorie des jeux à champ moyen a été initiée dans les années 2000 par deux groupes de chercheurs, Lasry et Lions en France, et Huang, Caines et Malhamé au Canada. L’objectif de cette théorie est de décrire les équilibres de Nash dans des jeux différentiels stochastiques incluant un grand nombre de joueurs interagissant les uns avec les autres à travers leur mesure empirique commune et présentant suffisamment de symétrie. Si l’existence d’équilibres dans les jeux à champ moyen est maintenant bien comprise, l’unicité reste connue dans un nombre très limité de cas. A cet égard, la condition la plus connue est celle dite de monotonie, due à Lasry et Lions. Dans cette thèse, nous démontrons, que pour une certaine classe de jeux à champ moyen, l’unicité peut être rétablie à l’aide d’un forçage aléatoire des dynamiques, communs à tous les joueurs. Un tel forçage est appelé “bruit commun”. Nous montrons également que, dans certains cas, il est possible de sélectionner des équilibres en l’absence de bruit commun en faisant tendre le bruit commun vers zéro. Enfin, nous montrons comment ces résultats s’appliquent à des problèmes de type “principal-agents”, avec un grand nombre d’agents en interaction. / The purpose of this thesis is to present several results on the restoration of uniqueness and selection of equilibria when uniqueness fails in mean field games. The theory of mean field games was initiated in the 2000s by two groups of researchers, Lasry and Lions in France, and Huang, Caines, and Malhamé in Canada. The aim of this theory is to describe the Nash equilibria in stochastic differential games involving a large number of players interacting with each other through their common empirical measure, under sufficient symmetry hypothesis. If the existence of equilibria in mean field games is now well understood, uniqueness remains known in a very limited number of cases. In this respect, the most well-known condition is the monotony hypothesis, due to Lasry and Lions. In this thesis, we demonstrate that for a certain class of mean field games, uniqueness can be restored by means of a random and common forcing, acting on all the players. Such a forcing is called “common noise”. We also show that in some cases it is possible to select equilibria in the absence of common noise by letting the common noise tend towards zero. Finally, we show how these results apply to “principal-agent” .problems, with a large number of interacting agents.

Inverse analysis of nonlinear dynamic systems is an important area of research in the eld of structural health monitoring for civil engineering structures. Structural damage usually involves localized nonlinear behaviors of dynamic systems that evolve into different classes of nonlinearity as well as change system parameter values. Numerous parametric modal analysis techniques (e.g., eigensystem realization algorithm and subspace identification method) have been developed for system identification of multi-degree-of-freedom dynamic systems. However, those methods are usually limited to linear systems and known for poor sensitivity to localized damage. On the other hand, non-parametric identification methods (e.g., artificial neural networks) are advantageous to identify time-varying nonlinear systems due to unpredictable damage. However, physical interpretation of non-parametric identification results is not as straightforward as those of the parametric methods. In this study, the Multidegree-ofFreedom Restoring Force Method (MRFM) is employed as a semi-parametric nonlinear identi- fication method to take the advantages of both the parametric and non-parametric identification methods. The MRFM is validated using two realistic experimental nonlinear dynamic tests: (i) largescale shake table tests using building models with different foundation types, and (ii) impact test using wind blades. The large-scale shake table test was conducted at Tongji University using 1:10 scale 12-story reinforced concrete building models tested on three different foundations, including pile, box and fixed foundation. The nonlinear dynamic signatures of the building models collected from the shake table tests were processed using MRFM (i) to investigate the effects of foundation types on nonlinear behavior of the superstructure and (ii) to detect localized damage during the shake table tests. Secondly, the MRFM was applied to investigate the applicability of this method to wind turbine blades. Results are promising, showing a high level of nonlinearity of the system and how the MRFM can be applied to wind-turbine blades. Fuiii ture studies were planned for the comparison of physical characteristic of this blade with blades created made of other material.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24220号 / 工博第5048号 / 新制||工||1788(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 五十嵐 晃, 教授 杉浦 邦征, 教授 KIM Chul-Woo / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

In everyday situations individuals make decisions. For example, a tourist usually chooses a crowded or recommended restaurant to have dinner. Perhaps it is an individual decision, but the observed pattern of decision-making is a collective phenomenon. Collective behaviour emerges from the local interactions that give rise to a complex pattern at the group level. In our example, the recommendations or simple copying the choices of others make a crowded restaurant even more crowded. The rules of interaction between individuals are important to study. Such studies should be complemented by biological experiments. Recent studies of collective phenomena in animal groups help us to understand these rules and develop mathematical models of collective behaviour. The most important communication mechanism is positive feedback between group members, which we observe in our example. In this thesis, we use a generic experimentally validated model of positive feedback to study collective decision-making. The first part of the thesis is based on the modelling of decision-making associated to the selection of feeding sites. This has been extensively studied for ants and slime moulds. The main contribution of our research is to demonstrate how such aspects as "irrationality", speed and quality of decisions can be modelled using differential equations. We study bifurcation phenomena and describe collective patterns above critical values of a bifurcation points in mathematical and biological terms. In the second part, we demonstrate how the primitive unicellular slime mould Physarum Polycephalum provides an easy test-bed for theoretical assumptions and model predictions about decision-making. We study its searching strategies and model decision-making associated to the selection of food options. We also consider the aggregation model to investigate the fractal structure of Physarum Polycephalum plasmodia. / <p>Fel serie i tryckt bok /Wrong series in the printed book</p>