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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.
101

(Des)apre(e)nder o ver com a paisagem: a expedição pela Paragem das Conchas

Junqueira, Lilian Maus January 2016 (has links)
Esta pesquisa nasce do encontro do olhar-expedicionário, sempre curioso e disposto a relacionar arte e ciência, com a Paragem das Conchas - nome atribuído à primeira sesmaria do Rio Grande do Sul, que corresponde hoje a um conjunto de municípios, dentre os quais, está Osório – lugar onde se desenvolvem as incursões aqui analisadas, entre os anos de 2012 e 2016. As experiências começam no ateliê, que funciona como um jardim onde se cultiva a linguagem do desenho, até que este lugar de produção de imagens abre-se e passa a ser compreendido como um observatório da natureza, fundindo-se, ao final, com a própria floresta. A principal pergunta que surge daí é: como se dá essa relação entre o ver e o conhecer a partir das experiências fenomenológicas com a paisagem que o meu trabalho artístico (obras em desenho, poesia, fotografia, objetos e instalação) proporciona? As rotas e o instrumental utilizados para as observações foram sendo redefinidos no próprio andar, como se fosse um Caminho de Peabiru, esse conjunto de trilhas indígenas cultivadas pelos Incas, que ligavam o Oceano Pacífico ao Atlântico. No andamento, foi preciso desaprender a ver o que eu pensava saber e aprender a ver o que não sabia que existia. O conjunto de trabalhos aqui apresentados forma um atlas onde procuro transmutar essas vivências por meio da linguagem poética. A narrativa divide a expedição em três momentos: Estudos sobre a terra | Estudos sobre a água | Estudos sobre o vento. A ação de expedir é interpretada em seu sentido literal de “liberar os pés das cadeias”. A pesquisa está dividida em dois volumes. No TOMO I apresento um percurso teórico em que o sol metaforiza, inicialmente, a relação entre o ver e o conhecer e, passo a passo, vai sendo eclipsado pela imagem da fogueira, que provoca uma queima de arquivo em que é necessário transmutar as memórias. O TOMO II é um livro de artista concebido a partir das travessias por TERRA (“Inventário de Fauna e Flora” e “Herbarium”), ÁGUA (“Travessia de Beija-Flor por águas doces”) e AR (“Tipologia do Mar – Escala Beaufort” e “Tipologia das nuvens – L. Howard”). / This research was created from the meeting of the expeditionary perspective, always curious and open to connect art and science, and Paragem das Conchas - the name given to the first sesmaria in Rio Grande do Sul - which today corresponds to a few different cities, amongst them Osório - the chosen spot for this expedition, which took place between 2012 and 2016. The experiences begin in the studio, which acts as a garden to cultivate the drawing language, till this image-production site opens up to be acknowledged as a nature observatory, ultimately merging with the forest itself. The main question that arises from that is: how does the relationship between seeing and knowing from phenomenological experiences in the landscape that my artistic work (drawing, poetry, photography, objects and art installation) provides me presents itself? The routes and instruments used in the observational trips were redefined while they were happening, such as in Caminho de Peabiru, the indigenous trails created by the Incas connecting the Pacific Ocean to the Atlantic. As the project went on, I had to unlearn how to see what I thought I knew and learn how to see what I did not know existed. The body of work presented here forms an atlas where I seek to transmute those experiences into a poetic narrative. The expedition was divided between three installments: Studies of the earth | Studies of the water | Studies of the wind. “Expedition” is interpreted here in a literal sense, that of “freeing the feet from the chains.” The research is divided in two volumes. In TOME I the theoretical path is presented, initially, in a way in which the sun acts as a metaphor of the relationship between seeing and knowing and, gradually, is eclipsed by the image of the bonfire, which leads to an indispensable documentation burning in order to transmute memories. TOME II is an artistic book created from crossings through land (“Inventário de Fauna e Flora” and “Herbarium”), water (“Travessia de Beija-Flor por águas doces”) and air (“Tipologia do Mar – Escala Beaufort” and “Tipologia das nuvens – L. Howard”).
102

Desconexão longitudinal de habitats em riachos neotropicais: ictiocenose sob influência de tubulações / Longitudinal disconnection of habitats in neotropical streams: fish assemblages under the influence of culverts

Mariano, José Roberto 19 August 2011 (has links)
Made available in DSpace on 2017-07-10T18:13:30Z (GMT). No. of bitstreams: 1 Jose Roberto Mariano.pdf: 761006 bytes, checksum: 1ff3542b379bbf2cc1b28957af1d8d39 (MD5) Previous issue date: 2011-08-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The insertion of culverts in streams may cause habitat degradation, changing patterns of migration and dispersal of species, causing deterioration of biological diversity over time, favoring the disconnection of the habitat. This study aimed to evaluate the fish assemblages between the upstream and downstream segments of box and circular culverts in neotropical streams. Specifically we intend to analyze the composition and structure of the ichthyofauna and its possible spatial patterns, as well as the occurrence of spawning. Sampling for fish fauna were carried out monthly between November 2009 and October 2010, with various fishing gear such as gillnet, sieve, rod and castnet. Samples of ichthyoplankton were conducted between October 2009 and March 2010, with plankton net. During the period 2220 individuals were collected, with 901 fish in segments of circular culvert and 1,310 fish in segments of box culvert, belonging to 33 species. Catches were similar in both upstream and downstream segments of the circular culvert, whereas in the box culvert the fish abundance was just over in the upstream segment against downstream. The Characiformes dominated with a larger number of individuals in the upstream stretch of both culverts. On the other hand, the Siluriformes were abundant in the downstream stretch of the circular culvert, with similar abundances among the sections of box culvert. The richness and diversity of species differed among the sections of circular culvert (higher value in downstream), while values were similar to portions of the box culvert. The most abundant species were Astyanax altiparanae, A. paranae, A. fasciatus, Ancistrus sp., and Hypostomus sp., but with differences in the occurrence of the latter two species: these were more abundant in downstream segment of the circular culvert, and similar in sections of box culvert. The ichthyoplankton sampled was very low, with records of 36 eggs, 05 juveniles and 03 larvae, especially in the downstream section of the culverts. The ichthyofauna obtained distinct patterns among the culverts and in particular between the upstream and downstream sections of circular culvert. The data presented here showed that the circular culvert seems to provoke more limitation to fish movement, acting as a barrier to the species, especially for the Siluriformes, which reflects the variations that exist in abundance, richness and diversity of species. This indicates the need for further studies in neotropical streams intercepted by culverts, aimed to assemblies of fish and their movement. Such studies may subsidize the responsible sectors for the implementation of these structures to propose possible solutions to improve the habitat conditions, adapting the engineering biology of the species. / A implantação de tubulações em riachos pode causar a degradação do habitat, alterando os padrões de migração e dispersão das espécies, gerando deterioração da diversidade biológica ao longo do tempo, favorecendo a desconexão do habitat. O presente estudo teve como objetivo avaliar a influência das assembléias de peixes entre os segmentos de montante e jusante de tubulações quadrada e circular em riachos neotropicais. Especificamente pretende-se analisar a composição e a estrutura das da ictiofauna e seus possíveis padrões espaciais, bem como a ocorrência de desovas. As amostragens para a ictiofauna foram realizadas mensalmente, entre novembro de 2009 e outubro de 2010, com diversos apetrechos de pesca como rede, peneirão, caniço e tarrafa. As amostragens do ictioplâncton foram realizadas entre o outubro de 2009 e março de 2010, com uma rede de plâncton. Durante o período foram coletados 2.220 indivíduos, sendo 901 peixes nos trechos da tubulação circular e 1.310 peixes nos trechos da tubulação quadrada, pertencentes a 33 espécies. As capturas foram semelhantes nos trechos de montante e jusante na tubulação circular, enquanto que para a tubulação quadrada a abundância de peixes foi um pouco superior no trecho a montante em relação a jusante. Os Characiformes predominaram com maior número de indivíduos no trecho a montante de ambas as tubulações. Por outro lado, os Siluriformes foram abundantes no trecho a jusante da tubulação circular, com abundâncias similares entre os trechos da tubulação quadrada. A riqueza e a diversidade de espécies diferiram entre os trechos da tubulação circular (maior valor a jusante), enquanto que os valores foram similares para os trechos da tubulação quadrada. As espécies mais abundantes foram Astyanax altiparanae, A. paranae, A. fasciatus, Ancistrus sp. e Hypostomus sp., porém com diferenças constatadas na ocorrência das duas últimas espécies: estas foram mais abundantes a jusante da tubulação circular, e similares nos trechos da tubulação quadrada. O ictioplâncton amostrado foi pouco expressivo, com registros de 36 ovos, 05 jovens e 03 larvas especialmente no trecho de jusante das tubulações. A ictiofauna obteve padrões distintos entre as tubulações e em especial entre os trechos de montante e jusante da tubulação circular. Os dados aqui apresentados evidenciam que a tubulação circular parece exercer maior limitação ao movimento dos peixes, atuando como uma barreira para as espécies, em especial aos Siluriformes, o que reflete nas variações existentes na abundância, riqueza e diversidade das espécies. Isso indica a necessidade de maiores estudos em riachos neotropicais interceptados por tubulações, voltados às assembleias de peixes e sua movimentação. Esses estudos poderão subsidiar os setores responsáveis pela implantação dessas estruturas no sentido de propor possíveis soluções para a melhoria das condições dos habitats, adequando a engenharia a biologia das espécies.
103

Les possibilités de dispersion et éléments d'habitat-refuge dans un paysage d'agriculture intensive fragmenté par un réseau routier dense : le cas de la petite faune dans la plaine du Bas-Rhin / Dispersal possibilities and refugial habitats in a intensive agricultural landscape fragmented by a dense road network : the case of small animals in the Bas-Rhin plain

Jumeau, Jonathan 16 October 2017 (has links)
La fragmentation des paysages et des habitats induite par les infrastructures linéaires de transport terrestres est une des principales causes de la perte de biodiversité actuelle. Parmi ces infrastructures, la route est un acteur majeur de fragmentation, d’autant plus qu’elle possède des effets propres dus au trafic circulant qui induit des collisions véhicule-faune et une pollution des paysages. Afin de diminuer ces effets négatifs, des mesures de réduction sont mises en place, notamment des passages à faune permettant de faire traverser la faune de part et d’autre des voies. La route crée aussi de nouveaux habitats potentiels pour les espèces de la petite faune dans des paysages anthropisés et fragmentés. Dans ce mémoire sont démontrées (1) la potentialité d’habitat de différents éléments routiers ; (2) la possibilité de prédire les collisions véhicule-faune afin de positionner au mieux les mesures de réduction ; (3) l’importance de la méthodologie dans l’évaluation de l’efficacité des passages à faune ; et (4) la possibilité d’améliorer les passages à faune existants. Ces résultats permettront d’améliorer les stratégies de défragmentation des paysages. / Habitats and landscape fragmentation, caused by linear land transports infrastructures, is one of the major cause for the current loss of biodiversity. Among those infrastructures, road is a major cause of fragmentation, especially as it possess specific traffic-linked effects, which induces wildlife-vehicles collisions and landscape pollution. In order to decrease those negative effects, mitigation measures are taken, among which wildlife crossings, enabling wildlife to cross the road. Road also creates new potential habitats for small wildlife species in anthropogenic and fragmented landscapes. In this essay are shown (1) the potential as habitat of different road-linked elements; (2) the possibility to anticipate wildlife-vehicles collisions in order to improve the position of mitigation measures; (3) the importance of methodology in the evaluation of wildlife crossings effectiveness; and (4) the possibility to improve existing wildlife crossings. Those results will allow improving landscape defragmentation strategies.
104

Border Crossings and Transnational Movements in Sandra Cisneros’ Spatial Narratives Offer Alternatives to Dominant Discourse

Vallecillo, Raquel D 30 March 2017 (has links)
My study aims to reveal how ideologies, the way we perceive our world, what we believe, and our value judgments inextricably linked to a dominant discourse, have real and material consequences. In addition to explicating how these ideologies stem from a Western philosophical tradition, this thesis examines this thought-system alongside selections from Sandra Cisneros’ Woman Hollering Creek and Caramelo or Puro Cuento. My project reveals how Cisneros’ spatial narratives challenge ideologies concerning the border separating the United States and Mexico, which proves significant as the project of decolonization and understanding of identity formation is fundamentally tied to these geographical spaces. Through the main chapters in this thesis, it is proposed that Cisneros’ storytelling does not attempt to counter fixed ideas of spaces and identity or an alleged objective Truth and single History by presenting a true or better version, but offers alternative narratives as a form of resistance to dominant discourse.
105

Spectral And Temporal Zero-Crossings-Based Signal Analysis

Shenoy, Ravi R 01 1900 (has links) (PDF)
We consider real zero-crossing analysis of the real/imaginary parts of the spectrum, namely, spectral zero-crossings (SZCs). The two major contributions are to show that: (i) SZCs provide enable temporal localization of transients; and (b) SZCs are suitable for modeling transient signals. We develop a spectral dual of Kedem’s result linking temporal zero-crossing rate (ZCR) to the spectral centroid. The key requirement is stationarity, which we achieve through random-phase modulations of the time-domain signal. Transient signals are not amenable to modelling in the time domain since they are bursts of energy localized in time and lack structure. We show that the spectrum of transient signals have a rich modulation structure, which leads to an amplitude-modulation – frequency-modulation (AM-FM) model of the spectrum. We generalize Kedem’s arc-cosine formula for lags greater than one. For the specific case of a sinusoid in white Gaussian noise, He and Kedem devised an iterative filtering algorithm, which leads to a contraction mapping. An autoregressive filter of order one is employed and the location of the pole is the parameter that is updated based on the filtered output. We use the higher-order property, which relates the autocorrelation to the expected ZCR of the filtered process, between lagged ZCR and higher-lag autocorrelation to develop an iterative higher-order autoregressive-filtering scheme, which stabilizes the ZCR and consequently provides robust estimates of the autocorrelation at higher lags. Next, we investigate ZC properties of critically sampled outputs of a maximally decimated M-channel power complementary analysis filterbank (PCAF) and derive the relationship between the ZCR of the input Gaussian process at lags that are integer multiples of M in terms of the subband ZCRs. Based on this result, we propose a robust autocorrelation estimator for a signal consisting of a sum of sinusoids of fixed amplitudes and uniformly distributed random phases. Robust subband ZCRs are obtained through iterative filtering and the subband variances are estimated using the method-of-moments estimator. We compare the performance of the proposed estimator with the sample auto-correlation estimate in terms of bias, variance, and mean-squared error, and show through simulations that the performance of the proposed estimator is better than the sample auto- correlation for medium to low SNR. We then consider the ZC statistics of the real/imaginary parts of the discrete Fourier spectrum. We introduce the notion of the spectral zero-crossing rate (SZCR) and show that, for transients, it gives information regarding the location of the transient. We also demonstrate the utility of SZCR to estimate interaural time delay between the left and right head-related impulse responses. The accuracy of interaural time delay plays a vital role in binaural synthesis and a comparison of the performance of the SZCR estimates with that of the cross-correlation estimates illustrate that spectral zeros alone contain enough information for accurately estimating interaural time delay. We provide a mathematical formalism for establishing the dual of the link between zero-crossing rate and spectral centroid. Specifically, we show that the expected SZCR of a stationary spectrum is a temporal centroid. For a deterministic sequence, we obtain the stationary spectrum by modulating the sequence with a random phase unit amplitude sequence and then computing the spectrum. The notion of a stationary spectrum is necessary for deriving counterparts of the results available in temporal zero-crossings literature. The robustness of location information embedded in SZCR is analyzed in presence of a second transient within the observation window, and also in the presence of additive white Gaussian noise. A spectral-domain iterative filtering scheme based on autoregressive filters is presented and improvement in the robustness of the location estimates is demonstrated. As an application, we consider epoch estimation in voiced speech signals and show that the location information is accurately estimated using spectral zeros than other techniques. The relationship between temporal centroid and SZCR also finds applications in frequency-domain linear prediction (FDLP), which is used in audio compression. The prediction coefficients are estimated by solving the Yule-Walker equations constructed from the spectral autocorrelation. We use the relationship between the spectral autocorrelation and temporal centroid to obtain the spectral autocorrelation directly by time-domain windowing without explicitly computing the spectrum. The proposed method leads to identical results as the standard FDLP method but with reduced computational load. We then develop a SZCs-based spectral-envelope and group-delay (SEGD) model, which finds applications in modelling of non-stationary signals such as Castanets. Taking into account the modulation structure and spectral continuity, local polynomial regression is performed to estimate the GD from the real spectral zeros. The SE is estimated based on the phase function computed from the estimated GD. Since the GD estimate is parametric, the degree of smoothness can be controlled directly. Simulation results based on synthetic transient signals are presented to analyze the noise-robustness of the SE-GD model. Applications to castanet modeling, transient compression, and estimation of the glottal closure instants in speech are shown.
106

Design d'interaction pour un "contact" à distance : suppléance perceptive du toucher et médiatisation de l'attente conjointe / Interaction design for a remote "contact" : perceptual supplementation of touch and joint attention mediatisation

Le Bihan, Gabrielle 04 December 2014 (has links)
Notre recherche se concentre sur la conception d’interfaces pour la communication émotionnelle à distance. Notre travail s’inscrit notamment dans le cadre de l’élaboration d’espaces numériques d’interactions tactiles, rendus possibles par la connexion en réseau de dispositifs de suppléance perceptive. Nous adoptons une approche énactive et interactionniste de la cognition sociale. Nous utilisons de plus la méthodologie minimaliste, qui offre une opportunité originale d’étudier la constitution des rencontres interpersonnelles au sein d’espaces mettant en place des couplages sensori-Moteurs inédits. Nous déroulons deux méthodologies, en articulant les domaines de la recherche fondamentale, de l’étude expérimentale et du design.Dans un premier temps, nous partons de la théorie autour du thème du toucher, avant de proposer une solution d’interface : l’application smartphone Touch Through. Elle permet une suppléance perceptive du toucher en se basant sur des propriétés fonctionnelles de ce sens. Touch Through sert ensuite à une expérimentation basée autour d’un test de Turing minimaliste, afin de tester la possibilité d’un sentiment de présence à distance avec notre application et de la mettre entre les mains d’utilisateurs.Dans un second temps, nous adressons la question de l’attention conjointe avant de mettre en place une étude expérimentale autour de ce thème (tâche de distinction entre des objets privés et des objets communs). Forts des résultats, nous proposons alors un prototype d’interface pour le réseau social facebook, en mettant en avant des possibilités d’attention conjointe au sein du site et en offrant une interaction inédite autour des posts. / Our research is aimed at designing interfaces for the remote communication of emotions. In particular our work is part of the development of tactile interaction digital spaces. These are made possible by a network connection between perceptual supplementation devices. We consider an enactive and interactionist approach of social cognition. In addition, we use a minimalist methodology. This offers an original opportunity to study the very constitution of interpersonal encounters within spaces where unprecedented sensorimotor couplings happen. We work through two methodologies, each articulating the fields of fundamental research, experimental study and design.In a first phase, we start from theory around the theme of touch, before proposing an interface solution – the smartphone application ‘Touch Through’. This application allows a perceptual supplementation of touch using its functional properties. ‘Touch Through’ is then used in a experimental study based on a minimalist Turing test. This experiment is about testing the possibility of a presence in absence feeling through our application. It was also an opportunity to have users handling it.In the second phase we address the question of joint attention. After a study of this question, we design an experiment where we propose a task of discrimination between private and common objects. Based on the outcome of this experiment, we then propose an interface prototype for the social network ‘facebook’. With this prototype interface, the facebook website is enhanced with possibilities of joint attention. In addition, facebook users can take part in an original interaction around posts.
107

Discrepancies in European Union policies towards illegal immigration : The securitisation of the visa-overstayer and the irregular migrant

Hansen, Frida January 2020 (has links)
Visa-liberalisation agreements are commonly used as an incentive by the EU to encourage cooperation within the realm of border and migration management with its neighbouring countries. The ultimate aim of these agreements is to reduce irregular migration to Schengen territory, something that has been percieved as an increasingly urgent issue for European policy makers in the wake of the 2015 'migration crisis'. However, the use of visa liberalisation agreements in such a fashion appears contradictory considering that most irregular migrants in the EU most likely are visa-overstayers. This essay takes of in this apparent puzzle and argues that securitisation theory might help us better understand this discrepancy. While the construction of the migrant as a security threat in Europe has been thoroughly examined, differences in securitisation between grups of irregular migrants are often left out of the discussion or only implicitly mentioned. By examining the discourse and practices of a central EU agency in regard to border and migration management, FRONTEX, this thesis shows that visa-overstayers are routinely left out of the securitised discussion on irregular migration, thus rendering EU policies asymmetrically occupied with irregular migration by means of 'illegal entry'. However, the thesis also uncovers a more conplex set of ideas that show that although visa-overstayers are not conceptulised as threats to security in discourse on par with other categories of irregular migrants, visa-goers and other travellers are, too, incresingly subjected to a rationale of survaillance and risk.
108

Vícesvodová rozhodovací pravidla v rozměřování signálů EKG / Multilead decision rules in delineation of ECG signals

Richter, Zdeněk January 2012 (has links)
This work deals with ECG signal measuring and methods of its processing. It compares some of the QRS detection methods and describes some of the testing databases. In this work a detector of QRS complex is realized, it is based on the approach of zero crossings. Next section makes combination of results from separate leads to one, which improves efficiency of detection. One section of this work deals with design and realization delination of ECG signal. In the last part outputs of this delineation are compared with the results of the other authors.
109

Návrh rekonstrukce železničních stanic Šternberk a Bohuňovice / Design of reconstruction of railway stations Šternberk nad Bohuňovice

Šatánek, Jan January 2017 (has links)
The design of reconstruction of railway stations Šternberk and Bohuňovice comprises the proposal to increase the line speed of the main track to the maximum possible value, the design of station tracks and reconstruction of railway switches and crossings, the design of the new platforms, which implements the requirements for people with reduced mobility and the design of new drainage system. Next, the design of reconstruction comprises the design of the railway superstructure and substructure and the design of railway level crossings.
110

Accurate Band Energies of Metals with Quadratic Integration

Jorgensen, Jeremy John 18 April 2022 (has links)
Materials play an important role in society. Historically, and even at present, materials have been discovered by trial and error, and many of the most useful materials have been discovered by chance. The high-throughput approach aims to remove (as much as possible) chance and guesswork at the experimental level by filtering out materials candidates that are not predicted to exist. Many successes have been recorded. In the high-throughput approach to materials discovery, machined-learned models of materials are created from databases of theoretical materials. These databases are the result of millions of density-functional-theory (DFT) simulations. The size and accuracy of the data in the databases (and, consequently, the predictions of machined-learned models) are most affected by the band energy calculation; most of the computation of a DFT simulation is computing the band energy in the self-consistency cycle, and most of the error in the simulation comes from band energy error. The band energy is obtained from a two-part multidimensional numerical integral over the Brillouin or irreducible Brillouin zone. A quadratic approximation and integration algorithm for computing the band energy in 2D and 3D is described. Analytic and semi-analytic integration of quadratic polynomials over simplices improves the accuracy and efficiency of the calculation. A method is proposed for estimating the error bounds of the quadratic approximation that does not require additional eigenvalues. Error propagation of approximation errors leads to an adaptive refinement approach that is driven by band energy error. Because adaptive meshes have little symmetry, integration is performed within the irreducible Brillouin zone, and a general algorithm for computing the irreducible Brillouin zone is described. The efficiency of quadratic integration is tested on realistic empirical pseudopotentials. When compared to current integration methods, uniform quadratic integration over the irreducible Brillouin zone sometimes results in fewer k-points for a given accuracy. Adaptive refinement fails to improve integration performance because band energy error bounds are inaccurate, especially at accidental crossings at the Fermi level.

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