Orientador: Célia Picinin de Mello / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-20T03:13:25Z (GMT). No. of bitstreams: 1 Almeida_SheilaMoraisde_D.pdf: 958566 bytes, checksum: ac97bf74cca2e690531df0f6d05c8a00 (MD5) Previous issue date: 2012 / Resumo: Por apresentar basicamente fórmulas, o resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Not informed / Doutorado / Ciência da Computação / Doutor em Ciência da Computação

Perfect slice sampling is a method to turn Markov Chain Monte Carlo (MCMC) samplers into exact generators for independent random variates. We show that the simplest version of the perfect slice sampler suggested in the literature does not always sample from the target distribution. (author's abstract) / Series: Research Report Series / Department of Statistics and Mathematics

We have studied several metamaterials structures with multiple layers by explaining them theoretically and verifying experimentally. The engineered structures we have designed work either as a perfect absorber or antireflection coating. The multilayer model as we call it Three Layer Model (TLM) has been developed, which gives the total reflection and transmission as a function of reflection and transmission of individual layers. By manipulating the amplitude and phase of the reflection and the transmission of the individual layers, we can get the required functionality of the optoelectronic devices. To get zero reflection in the both perfect absorber and the antireflection coating, the amplitude and phase conditions should be satisfied simultaneously. We have employed the numerical simulation of the structures to verify those conditions for all of the work presented here. As the theoretical retrieval method to extract the effective permittivity and effective permeability of the metamaterial contains air on the both side of the structure, we have dielectric at least on one side practically, that gives a little bit deviated result. We have modified the retrieval method to better fit with the multilayer structure by introducing air on the both side of the resonator using transfer matrix method and use it throughout all the works. We have explained the perfect absorption of the EM wave through Fabry-Perot cavity bounded by the resonator mirror and the metallic film. The metallic film acts as the close boundary whereas the resonator acts as the quasi-open boundary with very high effective permittivity, which leads to the characteristic feature of subwavelength thickness. We have shown numerically that the ultra-thin thickness makes the perfect absorber angular independent. We have also explained the phenomenon of perfect absorption through Impedance Matched Theory and Transmission Line Theory, and showed their matching with TLM. We have also developed the Meta Film Model by considering the resonator as a homogeneous thin film characterized by the effective permittivity and permeability giving rise to the same behavior as the original multilayer structure. We have shown that the resonance of the metamaterial resonator is very far from the resonance of the absorber, it behaves as the medium of high refractive index and very low loss. We have also shown that the density of states of the absorber is increased as compared to the resonator itself. We have investigated that the resonance peaks of the absorber arise from the combination of Fabry- Perot cavity modes and surface plasmon resonance modes. All the modes with increased spacer thickness are assigned with specific names describing the mode profiles. We have shown the application of perfect absorber as a refractive index sensor. It is used as a plasmonic sensor to detect the refractive index change of the chemical and biological samples. To increase the sensitivity, we have etched the dielectric spacer below the resonator, where electric field is localized and enhanced. We have found that the sensitivity (wavelength shift per refractive index change) and the Figure of Merit (FOM*) as an indicator of performance of the device both are enhanced significantly. We have employed metamaterial (MM) anti-reflection (AR) coating to avoid the shortcomings of the conventional thin film coating in three different cases of the structures. At first, we have deployed metamaterial Metal Disk Array (MDA) on the top of conventional coating material (BCB) with homogeneous substrate to enhance the transmission of EM wave. Then conventional AR coating is employed to the dispersive media (metal Hole Array) to enhance the transmission. We have shown that Impedance matched condition has been satisfied not only for homogeneous media, but for dispersive media also. At the end, we have employed the MM AR coating to the MM dispersive media (MHA). The two MM layers may interact with each other and may degrade the SPP wave of the MHA, which is essential to enhance the performance of the devices. To investigate the effect of interaction, we perform the simulation of the MDA, which shows that the resonance of the MDA is far from the antireflection resonance and hence the electric field of the SPP is significantly increased (~30%). With an improved retrieval method, the metasurface is proved to exhibit a high effective permittivity (εeff~30) and extremely low loss (tanδ~0.005). For all of the three AR structures, a classical thin film AR coating mechanism is identified through analytical derivations and numerical simulations. The properly designed εeff and μeff of the meta surface lead to the required phase and amplitude conditions for the AR coating, thereby paving the way for the improved performance of the optoelectronic devices. We have used MHA as a dispersive media to get extraordinary optical transmission (EOT). To understand the behavior of the SPP peaks, we have investigated the shifting and splitting of the spoof SPP resonance by varying the polar angle and azimuthal angle. The amplitude of extraordinary optical transmission also shows angle dependence and exhibits mirror-image or translational symmetries. Our measurements and simulations of the THz spoof SPP waves match very well with the theoretical predictions. The angle dependence results provide the important information for designing THz plasmonic devices in sensor and detector applications.

Most of the Germanic languages developed new tense forms allowing the grammatical expression of fine semantic distinctions, including periphrastic perfects and pluperfects; previously, the preterite alone had been used to express semantic content of this sort. In the absence of robust quantitative data regarding the subsequent development of these forms and distribution in the early Germanic languages, a relatively uncomplicated model has generally been assumed, in which there is little synchronic variation in their use and a steady, though not necessarily continuous, diachronic progress toward the state observed in the modern languages. The goal of this work is to provide accurate quantitative data regarding the apportionment of these semantic domains among the available grammatical forms in Old English and Old Saxon, in order to provide meaningful measurements of the synchronic and diachronic use of the periphrastic forms. Very different patterns were found in the use of these forms in the two languages. In Old Saxon the periphrastic forms are used freely, with a frequency similar to or greater than that of the preterites. In Old English there are no significant diachronic trends, but considerable variation exists synchronically among texts, with some making free use of the periphrastic forms and others preferring the preterite almost exclusively. A number of factors potentially responsible for this variation have been investigated, but none can account for the entire range of observed variation on its own. In the absence of any other account for the observed variation, the hypothesis is proposed that the periphrastic forms and the preterite differed in their perceived stylistic value, in a manner whose exact nature may be no longer recoverable; such a hypothesis would be in keeping with previous findings regarding languages such as Middle English and Middle High German. Old English and Old Saxon would therefore differ in the extent to which they make use of the potential for variation created by the absence of a paradigmatic opposition among the relevant grammatical categories.

The question of adverbs and the meaning of the present perfect across varieties of English is central to sociolinguistic variationist methodologies that have approached the study of the present perfect (Winford, 1993; Tagliamonte, 1997; van Herk, 2008, 2010; Davydova, 2010; Tagliamonte, 2013). This dissertation attempts to disentangle the effect of adverbial support from the three canonical readings of the present perfect (Resultative, Experiential and Continuative). Canadian English, an understudied variety of English, is used to situate the results seen in the Early Modern English data. Early Modern English reflects the time period in which English has acquired the full modern use of the present perfect with the three readings. In order to address both these questions and current controversies over statistical models in sociolinguistics, different statistical models are used: both the traditional Goldvarb X (Sankoff, Tagliamonte and Smith, 2005) and the newer mixed-effects logistic regression (Johnson, 2009). What is missing from the previous literature in sociolinguistics that advocates logistic mixed-effects models, and provided in this dissertation, is a clear statement of where they are inappropriate to use and their limitations. The rate of adverbial marking of the present perfect in Canadian English falls between rates reported for US and British English in previous studies. The data show in both time periods that while adverbs are highly favored in continuative contexts, they are strongly disfavored in experiential and resultative contexts. In Early Modern English, adverbial support functions statistically differently for resultatives and experientials, but that difference collapses in the Canadian English sample. Both this and the other linguistic contexts support a different analysis for each set of data with respect to adverbial independence from the meaning of the present perfect form. Finally, when the focus of the analysis is on linguistic rather than social factors, both the traditional and newer models provide similar results. Where there are differences, however, these can be accounted for by the number of tokens and different estimation techniques for each model.

Orientador : Linda Gentry El-Dash / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-04T01:07:45Z (GMT). No. of bitstreams: 1 Elizi_CesarEduardoDuarte_M.pdf: 195109 bytes, checksum: 20ae879bedc5d26fdf03f2805bcd97c7 (MD5) Previous issue date: 2004 / Resumo: Essa dissertação visa avaliar a utilização de atividades de Foco na Forma na aquisição, por alunos brasileiros, do tempo verbal Present Perfect através de uma comparação com a Abordagem Comunicativa tradicional. Tal abordagem apresenta, apesar de diversas vantagens, uma limitação na competência gramatical final atingida por alunos de línguas estrangeiras. Uma possível causa dessa limitação, além de outras, é a insuficiência do insumo em fornecer ao aprendiz evidência negativa, i.e. informação sobre a agramaticalidade de frases para as quais L2 é um subconjunto de L1. O que vem sendo chamado de Foco na Forma (FonF, do inglês Focus on Form) funciona como uma intervenção em que se direciona a atenção do aprendiz para aspectos de L2 em meio a uma atividade que privilegia a troca de significados. Desta forma, ao contrário do que ocorre com o Foco nas FormaS (seguindo a nomenclatura de Michael Long ), o FonF não interrompe o ato comunicativo para o estudo e prática de itens gramaticais de maneira isolada, mas busca produzir um desvio temporário de atenção, por parte do aprendiz, enquanto este está empenhado em realizar uma tarefa de compreensão ou produção. Descrevemos o Present Perfect como uma estrutura de difícil análise por parte do aluno brasileiro. Isto se deve, em parte, à má qualidade da maioria dos materiais didáticos disponíveis em relação a essa estrutura. O experimento realizado comparou dez salas de aula de quinto estágio de inglês com relação ao desempenho em pré e pós testes que avaliavam a habilidade dos alunos em (a) reconhecer a forma verbal correta para frases em meio a distratores, (b) identificar frases contendo a estrutura alvo como gramaticais ou não e (c) reproduzir por escrito um texto lido pelo professor contendo quatro ocorrências da estrutura alvo. Entre os dois testes utilizou-se três tipos de tratamento : (1) baseado em compreensão de textos; (2) baseado na reprodução escrita de textos e (3) sem Foco na Forma. Os resultados obtidos se mostram favoráveis ao uso de FonF para o Present Perfect e sugerem que atividades de compreensão de texto são mais benéficas que as de reprodução. Uma pergunta de conscientização ( o que você aprendeu?) feita à parte dos grupos dos tratamentos (1) e (2) resultou em uma melhoria de desempenho ainda maior para o grupo de compreensão de textos. Isto nos leva à hipótese de que convidar o aluno a refletir sobre sua aprendizagem auxilia na percepção de elementos novos, possivelmente por ativar processos cognitivos apenas disponíveis (sobretudo no tocante à filtragem de estímulos presentes no insumo) quando o objeto de estudo desperta no aluno um elemento de relevância pessoal / Abstract: The objective of this dissertation is to evaluate the use of Focus on Form in the acquisition of the verb tense Present Perfect by Brazilian students through a comparison with the traditional Communicative approach. This approach presents, despite several advantages, a limitation in the final grammatical competence attained by students. A possible reason for such limitation, among others, is the insufficiency of input alone in providing negative evidence, i.e. information about the agrammaticality of phrases for which L2 is a subset of L1. What has been labeled as Focus on Form, or FonF for short, is an intervention in which we direct students¿ attention to aspects of L2 during an activity aimed at the exchange of meaning. In this way, unlike what happens with Focus on FormS ( following Michael Long¿s terminology), FonF does not interrupt a communicative act in exchange for the isolated study and practice of grammar structures, but tries to divert students¿ attention momentarily, while they are engaged in a meaningful comprehension or production task. The Present Perfect is a structure which presents several difficulties to the Brazilian learner. This is partly due to the misleading explanations presented by most textbooks available. The experiment compared ten groups at level 5 in terms of their performance in pre and post tests. These tests evaluated the students¿ ability to (a) select the correct verb forms for incomplete sentences among distractors; (b) classify sentences containing the target-structure as either grammatically correct or not and (c) reconstruct in writing a text read aloud by the teacher which contained four instances of the target structure. Three different treatments were used : (1) with FonF tasks based on reading comprehension; (2) with FonF tasks based on text reconstruction and (3) without FonF. The results are in favour of the use of FonF activities for the Present Perfect and suggest that reading comprehension tasks are more beneficial than the text reconstruction ones. An awareness-raising question (what did you learn?) which was asked to some of the groups (1) and (2) resulted in an even better performance by the groups working with reading comprehension tasks. This has led to the hypothesis that asking the students to reflect upon their learning facilitates the noticing of new elements, possibly by activating cognitive processes only available ( particularly in what concerns the filtering of stimuli present in the input) when the object of study triggers an element of personal relevance in the student / Mestrado / Mestre em Linguística Aplicada

Dans cette thèse, nous nous intéressons aux équations aux dérivées partielles hyperboliques sous contraintes ; plus particulièrement aux problèmes provenant de la mécanique de la plasticité parfaite. Un bref historique de l'origine mécanique des problèmes de la plasticité parfaite ainsi que des résultats précédemment obtenus sont décrits dans le Chapitre 1. Dans le Chapitre 2, nous concentrons notre attention sur les systèmes hyperboliques avec conditions de bord. Nous développons une théorie faible pour ces problèmes et expliquons dans un cas simplifié le caractère bien posé de cette théorie. Puis, nous introduisons de manière similaire la notion de solution faible pour des systèmes hyperboliques avec condition de bord soumis à une contrainte. Nous nous dédions, dans le chapitre 3, à l'étude d'un modèle simplifié de la dynamique de la plasticité parfaite. Nous confrontons l'approche introduite au chapitre précédent avec celle, plus classique, provenant du calcul des variations qui permet d'obtenir l'existence et l'unicité des solutions pour ce modèle. Cela nous permet de mettre en évidence une nouvelle interaction entre les conditions de bord et les contraintes ainsi que d'aboutir à un théorème de régularité des solutions. Dans le chapitre 4, nous nous intéressons à l'approximation numérique des systèmes hyperboliques sous contraintes grâce à des schémas de type volumes finis. Cela nous permet d'obtenir un résultat de convergence pour les problèmes sans bord et d'illustrer numériquement les interactions entre les conditions de bord et les contraintes sur l'exemple du chapitre 3. / In this thesis, we consider constrained hyperbolic partial differential equations and more precisely mechanical problems coming from perfect plasticity. The goal of this thesis is to study these problems thanks to different approaches, to analyze the interactions between these different points of view and to confront these various analyzes to get new results. A brief review of the mechanical origin of perfect plasticity problems and also of the previous results on these topics are described in Chapter 1. In Chapter 2, we focus our attention on hyperbolic systems with boundary conditions. First, we develop a weak theory for these problems and explain, in a simplified case, why this theory is well-posed. Then, we introduce similarly a notion of weak solutions for constrained hyperbolic systems with boundary conditions. Chapter 3 is devoted to the study of the simplified model of dynamical perfect plasticity. We confront the approach introduced in the previous chapter with the one, more standard, coming from calculus of variations that allows us to obtain existence and uniqueness of the solutions for this model. It allows us to bring to light a new interaction between the boundary conditions and the constraints and to get a short-time regularity theorem. Lastly, in Chapter 4, we are interested in the numerical approximation of constrained hyperbolic systems thanks to finite volume schemes. This work allows us to get a convergence result for problems without boundary condition and to show numerically the link between boundary conditions and constraints on the example of the previous chapter.

付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(経済学) / 甲第22111号 / 経博第604号 / 新制||経||291(附属図書館) / 京都大学大学院経済学研究科経済学専攻 / (主査)教授 依田 高典, 教授 岡 敏弘, 講師 五十川 大也 / 学位規則第4条第1項該当 / Doctor of Economics / Kyoto University / DGAM

As the decline in Arctic sea ice extent makes this region more accessible, the need is increasing for effective seasonal sea ice forecasting to facilitate operational planning. Recently, coupled global climate models (CGCMs) have been used to address the need for effective sea ice forecasting on seasonal time scales. This thesis assesses the operational utility of the Canadian Seasonal to Interannual Prediction System (CanSIPS) for seasonal sea ice forecasting. This assessment consists of two separate studies. The first uses hindcasting to analyze the skill of two versions of CanSIPS, as well as an intermediate version, on the pan-Arctic as well as regional scales. This approach allows for an overall assessment of the system's skill in addition to providing insight with regards to the features in each version which improved that skill. This study finds that the use of a new initialization procedure for sea ice concentration and thickness improved forecast skill on the pan-Arctic scale as well as in the Central Arctic, Barents Sea, Laptev Sea, and Sea of Okhotsk. This study also shows that the substitution of one of the constituent models in the system improved forecast skill on the pan-Arctic scale as well as in the GIN, Barents, Kara, East Siberian, Chukchi, Bering, and Beaufort Seas. Overall, the new version of CanSIPS was found to be generally more skillful than previous versions. The second study conducts a potential predictability experiment on CanCM4, the constituent CGCM common to all versions of CanSIPS considered in this study. This study follows the methodology introduced by \cite{Bushuk2018} which allows for a more complete assessment of the dependency of potential predictability on initialization month than previous studies and for comparisons to be made between potential predictability and operational skill. This analysis is again done on both the pan-Arctic and regional scale. The findings of this experiment show that CanCM4 has relatively low potential predictability relative to other models and explains results previously presented in a multi-model study by \cite{Day2016}. Further, the characteristics of CanCM4's potential predictability share similarities with other models including greater predictability at longer lead times for winter target months than summer target months, greater predictability in the Atlantic sector than the Pacific sector, and the presence of the spring predictability barrier on the pan-Arctic scale as well as in several regions. The comparison of operational skill to potential predictability provides a general overview of the ``skill gap" which may be closed with improvements in initialization procedures and model physics. This comparison does, however, come with some caveats due to differences in the statistical characteristics of the perfect model and the climate system it represents. Together, the operational skill assessment of different versions of CanSIPS and the potential predictability experiment conducted on one of its constituent models, CanCM4, demonstrate that while room for improvement exists, the recent development of this forecast system has clearly increased its operational utility as a seasonal sea ice forecasting tool. / Graduate

The historic portrayal of the teenage girl in cinema as a mythical, sexual, hyper feminine and contemporary creature makes way for a specific but fairly common trope. Namely a trope where the teenage girl is used to elicit nostalgia and romance for the male protagonist, specifically because of her trauma and pain. The connection between the youth, femininity, pain and her status as contemporary is what makes the teenage girl an especially nostalgic object. Sofia Coppola’s The Virgin Suicides is a film that perfectly highlights and exaggerates this trope. By analyzing this film as well as comparing it to earlier examples, this essay will problematize this portrayal and locate its roots. This essay will analyze these examples and compare them to the general portrayal of the teenage girl in cinema during the twentieth century. By looking at The Virgin Suicides through the theory of the male gaze and the female spectacle, Coppola’s highlighting of this trope becomes clear. This essay concludes that it is unclear if Coppola subverts or simply leans into this trope, but it becomes evident that it is a trope built on the fact that pain and deadness is the height of perfect femininity. Perfect femininity in turn can only be achieved during adolescence, and therefore, the trauma of female adolescence becomes nostalgic.