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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Chemistry of Extrasolar Planetary Systems

Bond, Jade January 2008 (has links)
This work examines the chemical nature of extrasolar planetary systems, considering both the host star and any potential terrestrial planets located within the system. Extrasolar planetary host stars are found to be enriched over non-host stars in several r- and s-process elements. These enrichments, however, are in keeping with general galactic chemical evolution trends. This implies that host stars have not experienced any unusual chemical processing or pollution and that the observed enrichments are primordial in nature.When combined with detailed chemical models, the dynamical models of O'Brien et al. (2006) are found to produce terrestrial planets with bulk elemental abundances in excellent agreement with observed planetary values. This clearly indicates that the combination of dynamical and chemical modeling applied here is successfully reproducing the terrestrial planets of the Solar System to the first order. Furthermore, these planets are found to form with a considerable amount of water, negating the need for large amounts of exogenous delivery. Little dependence on the orbital properties of Jupiter and Saturn is observed for the main rock-forming elements due to the largely homogenous disk composition calculated.The same modeling approach is applied to known extrasolar planetary systems. Terrestrial planets were found to be ubiquitous, forming in all simulations. Generally, small (< 1ML) terrestrial planets are produced close to their host star with little radial mixing occurring. Planetary compositions are found to be diverse, ranging from Earth-like to refractory dominated and C-dominated, containing significant amounts of carbide material. Based on these simulations, stars with Solar elemental ratios are the best place to focus future Earth-like planet searches as these systems are found to produce the most Earthlike terrestrial planets which are located within the habitable zones of their systems and containing a significant amount of water. C-rich planets, although unusual, are expected to exist in >20% of known extrasolar planetary systems based on their host star photospheric compositions. These planets are unlike any body we have previously observed and provide an exciting avenue for future observation and simulation.
2

Entre discos e lobos: o medo e o insólito revelados pelas ausências nas obras Vinil Verde e Os lobos dentro das paredes / Between disks and wolves: the fear and the unusual revealed by the absences in the works Vinil Verde and Os lobos dentro das paredes

Guimarães, Maria de Lourdes 08 November 2017 (has links)
A presente tese procurou estudar como a ausência, representada por elementos como a incomunicabilidade, a não-identificação, o entre-lugar, a perda e a morte, dentre outros, ajuda a deflagrar atmosferas e emoções de insólito e de medo nas obras Vinil Verde (2004), curta-metragem de Kleber Mendonça, e Os lobos dentro das paredes (2006), narrativa gráfica de Neil Gaiman. Em ambos os enredos, o mundo ficcional dos personagens é desestabilizado por fatos inexplicáveis que se sobrepõem à rotina do cotidiano. A ausência faz parte da existência humana e, como recurso estético, ajuda a construir variados sentimentos, sensações e ambientações, como a solidão e a melancolia. Dentre os efeitos que ela pode provocar, estão os do insólito e o do medo. O insólito na narrativa ficcional carrega a força e a potência de desestruturar a ordem, provocando incômodo, estranhamento e dúvida. O medo, por sua vez, é uma sensação inerente ao ser humano que, no campo ficcional, como experiência estética, tem fascinado crianças, jovens e adultos, o que se traduz pelo grande número de produções literárias e fílmicas que se fundamentam no susto e no pavor. Por um viés comparativo e multidisciplinar, que engloba obras de diferentes suportes (um livro ilustrado e um audiovisual), foram postos em foco os principais recursos estéticos que cada suporte utilizou para revelar os traços de ausência e, como resultado, provocar o estranhamento e o medo. O profícuo diálogo entre as linguagens verbal, visual e sonora, em que a palavra, a imagem e o som se articulam para construir múltiplas significações e múltiplas leituras, proporciona uma rica troca de saberes e uma singular leitura de mundo. / The present thesis aimed to study how the absence, represented by elements such as incommunicability, non-identification, interlacing, loss and death, among others, helps to trigger atmospheres and emotions of unusual and fear in the works Vinil Verde (2004 ), a short film by Kleber Mendonça, and Os lobos dentro das paredes (2006), a graphic narrative by Neil Gaiman. In both scenarios, the fictional world of the characters is destabilized by inexplicable facts that overlap with the routine of everyday life. Absence is part of human existence and, as an aesthetic resource, helps to build different feelings, sensations and settings, such as loneliness and melancholy. Among its effects there are the unusual and the fear. The unusual in the fictional narrative carries the strength and power to eliminate the structure of order, causing annoyance, estrangement and doubt. As for the fear, it is an inherent sensation of the human being which, in the fictional field, as an aesthetic experience, has fascinated children, youth and adults, and is translated by a great number of literary and filmic productions that are based on fright and dread. Through a comparative and multidisciplinary study, which includes works of different supports (illustrated book and audiovisual), the main aesthetic resources that each media used to reveal traces of absence and cause strangeness or fear were highlighted. The fruitful dialogue between verbal, visual and sound languages, in which word, image and sound are articulated to construct multiple meanings and multiple readings, provides a rich exchange of knowledge and a unique \"reading\" of the world.
3

Unika hotell och vandrarhem : En studie om vad som gör unika boenden framgångsrika

Arnbert, Max, Krabbe, Elias January 2019 (has links)
No description available.
4

Detection of unusual fish trajectories from underwater videos

Beyan, Çigdem January 2015 (has links)
Fish behaviour analysis is a fundamental research area in marine ecology as it is helpful for detecting environmental changes by observing unusual fish patterns or new fish behaviours. The traditional way of analysing fish behaviour is by visual inspection using human observers, which is very time consuming and also limits the amount of data that can be processed. Therefore, there is a need for automatic algorithms to identify fish behaviours by using computer vision and machine learning techniques. The aim of this thesis is to help marine biologists with their work. We focus on behaviour understanding and analysis of detected and tracked fish with unusual behaviour detection approaches. Normal fish trajectories exhibit frequently observed behaviours while unusual trajectories are outliers or rare trajectories. This thesis proposes 3 approaches to detecting unusual trajectories: i) a filtering mechanism for normal fish trajectories, ii) an unusual fish trajectory classification method using clustered and labelled data and iii) an unusual fish trajectory classification approach using a clustering based hierarchical decomposition. The rule based trajectory filtering mechanism is proposed to remove normal fish trajectories which potentially helps to increase the accuracy of the unusual fish behaviour detection system. The aim is to reject normal fish trajectories as much as possible while not rejecting unusual fish trajectories. The results show that this method successfully filters out normal trajectories with a low false negative rate. This method is useful to assist building a ground truth data set from a very large fish trajectory repository, especially when the amount of normal fish trajectories greatly dominates the unusual fish trajectories. Moreover, it successfully distinguishes true fish trajectories from false fish trajectories which result from errors by the fish detection and tracking algorithms. A key contribution of this thesis is the proposed flat classifier, which uses an outlier detection method based on cluster cardinalities and a distance function to detect unusual fish trajectories. Clustered and labelled data are used to select feature sets which perform best on a training set. To describe fish trajectories 10 groups of trajectory descriptions are proposed which were not previously used for fish behaviour analysis. The proposed flat classifier improved the performance of unusual fish detection compared to the filtering approach. The performance of the flat classifier is further improved by integrating it into a hierarchical decomposition. This hierarchical decomposition method selects more specific features for different trajectory clusters which is useful considering the trajectory variety. Significantly improved results were obtained using this hierarchical decomposition in comparison to the flat classifier. This hierarchical framework is also applied to classification of more general imbalanced data sets which is a key current topic in machine learning. The experiments showed that the proposed hierarchical decomposition method is significantly better than the state of art classification methods, other outlier detection methods and unusual trajectory detection methods. Furthermore, it is successful at classifying imbalanced data sets even though the majority and minority classes contain varieties, and classes overlap which is frequently seen in real-world applications. Finally, we explored the benefits of active learning in the context of the hierarchical decomposition method, where active learning query strategies choose the most informative training data. A substantial performance gain is possible by using less labelled training data compared to learning from larger labelled data sets. Additionally, active learning with feature selection is investigated. The results show that feature selection has a positive effect on the performance of active learning. However, we show that random selection can be as effective as popular active learning query strategies in combination with active learning and feature selection, especially for imbalanced set classification.
5

O fantástico no contexto sócio-cultural do século XX: José J. Veiga (Brasil) e Mia Couto (Moçambique) / The Fantastic in the socio-cultural the twentieth century: Joseph J. Veiga (Brazil) and Mia Couto (Mozambique)

Rezende, Irene Severina 16 April 2009 (has links)
O desenvolvimento deste trabalho pautou-se em obras artísticas, engajadas politicamente, pertencentes ao macrossistema de Literaturas de língua portuguesa, a saber, uma Moçambicana: Um Rio chamado Tempo, uma Casa chamada Terra, de Mia Couto, e outra brasileira, Sombras de Reis Barbudos, de J.J. Veiga. A partir desse comparativismo entre os dois contextos, chegou-se a uma idéia do que é o fantástico contemporâneo, e procurou-se aprofundar o estudo sócio-cultural ressaltado nos conteúdos das duas obras. A temática \"opressão\" permitiu estudar as relações de poder e submissão entre as personagens das duas obras. Esta temática perpassou a análise crítico-literária fundamentando, filosoficamente, a atuação das personagens, reflexos muitas vezes da situação histórica vivenciada pelos autores. Semanticamente variada e polêmica, a palavra \"opressão\" prestou-se, nesta abordagem, a uma interpretação de possibilidade de um estudo sócio-cultural do momento em que as obras foram escritas, seguindo a linha filosófica desenvolvida pelo pensador alemão Sigmund Freud, no que se refere à interpretação do duplo. A pesquisa serviu-se de teóricos como Todorov, Caillois e Bessière, para a abordagem do gênero fantástico presente nas duas obras. Pelo fato de ter-se pesquisado toda a produção literária dos dois autores, sentiu-se a necessidade de citar outras obras, o que ajudou a estabelecer um diálogo entre as narrativas selecionadas e as demais obras dos dois escritores. Ao estudar as narrativas dos autores, pensou-se que fosse necessário uma inserção na história recente dos dois países cujo levantamento vem inserido nos anexos. Por não esquecer o contexto sócio-cultural da elaboração dos dois textos, é que a pesquisa espelha as circunstâncias históricas da época da criação das mesmas, sem deixar, contudo de perceber que a literatura vai além desse simples espelhar do real, pois a obra literária, além de dialogar com o mundo em que está inserida, dialoga com tempos e espaços outros que não os da realidade. A escolha desse tema se deu também pela indagação de ordem teórica, o que justifica a escolha do corpus, apresentado para estudo. / The development of this work is guided into artwork, politically engaged, belonging to the macrosystem of Literatures in English, namely, a Mozambican: A River called Tempo, a house call Earth, Mia Couto, and another Brazilian, Shadows of Kings Barbuda, from J.J. Veiga. From this comparative between the two contexts, it was an idea of what is the great contemporary, and tried to deepen the socio-cultural study highlighted in the contents of the two works. The theme oppression permitted to study the relationships of power and submission between the characters of the two works. This thematic been present throughout the literary-critical analysis reasons, philosophically, the actions of the characters, often reflected the historical situation experienced by the authors. Semantically varied and controversy, the word oppression is provided in this approach, the possibility of an interpretation of a study of socio-cultural moment in which the works were written, following the philosophical line developed by the German thinker Sigmund Freud, in refers to the interpretation of the double. The research was theoretical served as Todorov, Caillois and Bessière to the approach of gender in this fantastic two works. Because of having to be searched throughout the literature of the two authors, felt the need to quote other works, which helped to establish a dialogue between the narratives and other selected works of the two writers. By studying the narratives of the authors, it was thought it was a necessary insertion in the recent history of two countries whose survey is inserted in the annexes. Why not forget the socio-cultural context of the preparation of the two texts, is that the survey reflects the historical circumstances at the time of their creation, while, however, understand that the literature that goes beyond simple mirror of reality, because the literary work In addition to dialogue with the world around them, and argue with times and places other than the reality. The choice of this theme is also gave the theoretical question of order, hence the choice of the body, submitted for study
6

O modo fantástico em Mário de Sá-Carneiro / The fantastic in Mário de Sá-Carneiro

Bruno da Silva Soares 27 March 2013 (has links)
O presente trabalho discute como os conceitos do Fantástico se desenvolvem na obra em prosa do escritor modernista português Mário de Sá-Carneiro, comparando duas perspectivas teóricas distintivas sobre o tema. Uma dessas possibilidades implica perceber o Fantástico como um gênero literário numa perspectiva histórica , admitindo-o de forma mais restrita e restritiva; outra, como um modo discursivo numa perspectiva a-histórica , de caráter mais abrangente e acolhedor. A partir desses diferentes pressupostos, objetiva-se, estudando um conjunto de quatro narrativas curtas do autor (Loucura e Incesto, do livro Princípio, e A grande sombra e A estranha morte do Professor Antena, de Céu de fogo), averiguar a forma como Sá-Carneiro, valendo-se do recurso às estratégias de construção narrativa do Fantástico, além de poeta, torna-se um ícone da prosa portuguesa na viragem do século XIX para o XX, estabelecendo um referencial para a Literatura Fantástica em Portugal. Para realizar este estudo, foram utilizados conceitos teóricos de Tzvetan Todorov, Filipe Furtado, Irène Bessière e, tangencialmente, de outros variados estudiosos do Fantástico da contemporaneidade / This paper discusses how the concepts of Fantastic develop the prose work of the Portuguese modernist writer Mário de Sá-Carneiro, comparing two distinctive theoretical perspectives on the topic. One such possibility involves realizing Fantastic as a literary genre - a historical perspective - assuming the more restricted and restrictive; another, as a discursive mode - non-historical perspective - has a more comprehensive and welcoming. From these different assumptions, the objective of studying a set of four short stories from the author ("Loucura" and "Incesto" from the book Princípio and "A grande sombra" and "A estranha morte do Professor Antenna" from Céu em fogo, determine how Sá-Carneiro, using resource strategies of narrative construction of the Fantastic, and poet, becomes an icon of Portuguese prose becomes an icon of Portuguese prose at the turn of the nineteenth to the twentieth, establishing a benchmark for the Fantastic Literature in Portugal. To conduct this study, it was used theoretical concepts of Tzvetan Todorov, Filipe Furtado, Irène Bessière and tangentially, other assorted scholars from the Fantastic contemporaneity
7

Intelligent computer vision processing techniques for fall detection in enclosed environments

Rhuma, Adel January 2014 (has links)
Detecting unusual movement (falls) for elderly people in enclosed environments is receiving increasing attention and is likely to have massive potential social and economic impact. In this thesis, new intelligent computer vision processing based techniques are proposed to detect falls in indoor environments for senior citizens living independently, such as in intelligent homes. Different types of features extracted from video-camera recordings are exploited together with both background subtraction analysis and machine learning techniques. Initially, an improved background subtraction method is used to extract the region of a person in the recording of a room environment. A selective updating technique is introduced for adapting the change of the background model to ensure that the human body region will not be absorbed into the background model when it is static for prolonged periods of time. Since two-dimensional features can generate false alarms and are not invariant to different directions, more robust three-dimensional features are next extracted from a three-dimensional person representation formed from video-camera measurements of multiple calibrated video-cameras. The extracted three-dimensional features are applied to construct a single Gaussian model using the maximum likelihood technique. This can be used to distinguish falls from non-fall activity by comparing the model output with a single. In the final works, new fall detection schemes which use only one uncalibrated video-camera are tested in a real elderly person s home environment. These approaches are based on two-dimensional features which describe different human body posture. The extracted features are applied to construct a supervised method for posture classification for abnormal posture detection. Certain rules which are set according to the characteristics of fall activities are lastly used to build a robust fall detection model.
8

Towards Scalable Analysis of Images and Videos

Zhao, Bin 01 September 2014 (has links)
With widespread availability of low-cost devices capable of photo shooting and high-volume video recording, we are facing explosion of both image and video data. The sheer volume of such visual data poses both challenges and opportunities in machine learning and computer vision research. In image classification, most of previous research has focused on small to mediumscale data sets, containing objects from dozens of categories. However, we could easily access images spreading thousands of categories. Unfortunately, despite the well-known advantages and recent advancements of multi-class classification techniques in machine learning, complexity concerns have driven most research on such super large-scale data set back to simple methods such as nearest neighbor search, one-vs-one or one-vs-rest approach. However, facing image classification problem with such huge task space, it is no surprise that these classical algorithms, often favored for their simplicity, will be brought to their knees not only because of the training time and storage cost they incur, but also because of the conceptual awkwardness of such algorithms in massive multi-class paradigms. Therefore, it is our goal to directly address the bigness of image data, not only the large number of training images and high-dimensional image features, but also the large task space. Specifically, we present algorithms capable of efficiently and effectively training classifiers that could differentiate tens of thousands of image classes. Similar to images, one of the major difficulties in video analysis is also the huge amount of data, in the sense that videos could be hours long or even endless. However, it is often true that only a small portion of video contains important information. Consequently, algorithms that could automatically detect unusual events within streaming or archival video would significantly improve the efficiency of video analysis and save valuable human attention for only the most salient contents. Moreover, given lengthy recorded videos, such as those captured by digital cameras on mobile phones, or surveillance cameras, most users do not have the time or energy to edit the video such that only the most salient and interesting part of the original video is kept. To this end, we also develop algorithm for automatic video summarization, without human intervention. Finally, we further extend our research on video summarization into a supervised formulation, where users are asked to generate summaries for a subset of a class of videos of similar nature. Given such manually generated summaries, our algorithm learns the preferred storyline within the given class of videos, and automatically generates summaries for the rest of videos in the class, capturing the similar storyline as in those manually summarized videos.
9

Synthetic, spectroscopic and structural studies of chalcogen peri-substituted heterocycles : a solid-state NMR perspective

Sanz Camacho, Paula January 2016 (has links)
Chalcogen-containing materials are an area of increasing interest for spintronic applications. The synthesis, structures and reactivity of these novel compounds are normally studied by solution-state nuclear magnetic resonance (NMR) spectroscopy, density functional theory (DFT) calculations and single-crystal X-ray diffraction. In this thesis, a range of chalcogen-containing heterocycles has been explored, focussing on the solid-state nature and exploring the bulk samples. Therefore, all materials were studied by powder X-ray diffraction and solid-state NMR, in addition to conventional solution-state NMR and single-crystal X-ray diffraction. DFT calculations were also used to interpret the solid-state NMR spectra and to gain insight into the NMR parameters. In the first chapter of results, a series of mixed Te, Se acenaphthenes is investigated. 77Se and 125Te NMR parameters are explored to determine whether changes in the Te aryl-group have an impact on the local environments of both nuclei. Dynamics and the requirement to consider relativistic effects for calculations of NMR parameters of heavy atoms is discussed. In the second results chapter, a series of novel P-S and P-Se six-membered heterocycles are described in terms of their synthesis, reactivity, and 31P and 77Se local environments. We observed and measured some unusual “through-space” couplings that occur between molecules and which mechanism and pathways are supported by DFT calculations. In the third results chapter, these heterocycles are oxidised with O, S and Se and the NMR parameters are discussed in terms of the structure. Polymorphism, phase transitions and weak interactions are some of the phenomena present in these novel compounds. This thesis demonstrated that solid-state NMR is a very good probe to study Se- and Te-containing materials.
10

Le fantastique chez Baudelaire : la poétique de l'insolite / The fantastic in Baudelaire : the poetics of the unusual

Ouakaoui, Malek 11 April 2012 (has links)
Tzvetan Todorov définit le fantastique comme étant le propre de la nouvelle et non pas de la poésie et c’est un genre qui se situerait entre l’étrange et le merveilleux. Pourtant la poésie baudelairienne semble déroger à cette règle, tant au niveau formel que thématique. Les Petits Poèmes en prose constituent un genre hybride entre le recueil de nouvelles et le recueil de poèmes. Dans Les Fleurs du mal, l’ordre des pièces obéit à la logique d’un récit. Quant aux traductions des œuvres d’Edgar Poe, Baudelaire y injecte de la poésie. Sur le plan thématique, les motifs fantastiques sont présents dans l’œuvre de Baudelaire de manière quasi-systématique. Certains d’entre eux prennent des formes singulières et insolites chez l’écrivain. Et par le fait qu’il exalte la bipolarité formelle et thématique, le romantisme baudelairien n’est pas sans nous rappeler la démarche hoffmannienne de l’écriture. Tout en gardant à l’esprit la théorie de Todorov, nous essayons, pas à pas, de démontrer l’existence d’un fantastique baudelairien dont semble même s’inspirer certaines œuvres cinématographiques. / Tzvetan Todorov defines the fantastic as being a genre at the interface between the strange and the wonderful, a genre characteristic of the novel but not of poetry. Baudelaire's poetry, however, seems to depart from this rule, both formally and thematically. The Little Poems in Prose is a hybrid between the collection of short stories and that of poetry. In The Flowers of Evil, the order of the plays obeys the logic of a narrative. As for the translations of the works of Edgar Allan Poe, Baudelaire indulged into poetry. Thematically, the fantastic patterns are present in Baudelaire's work almost systematically. Some of them are unique and unusual forms to the writer. Given that he exalts the formal and thematic bipolarity, Baudelaire’s romance is not reminiscent of Hoffman's approach to writing. Bearing in mind the theory of Todorov, we attempt, step by step to demonstrate the existence of a Baudelairean fantasy which seems to have inspired even some films.

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