Fine-scale urban land cover information is important for a number of applications, including urban tree canopy mapping, green space analysis, and urban hydrologic modeling. Land cover information has traditionally been extracted from satellite or aerial images using automated image classification techniques, which classify pixels into different categories of land cover based on their spectral characteristics. However, in fine spatial resolution images (4 meters or better), the high degree of within-class spectral variability and between-class spectral similarity of many types of land cover leads to low classification accuracy when pixel-based, purely spectral classification techniques are used. Object-based classification methods, which involve segmenting an image into relatively homogeneous regions (i.e. image segments) prior to classification, have been shown to increase classification accuracy by incorporating the spectral (e.g. mean, standard deviation) and non-spectral (e.g. te xture, size, shape) information of image segments for classification. One difficulty with the object-based method, however, is that a segmentation parameter (or set of parameters), which determines the average size of segments (i.e. the segmentation scale), is difficult to choose. Some studies use one segmentation scale to segment and classify all types of land cover, while others use multiple scales due to the fact that different types of land cover typically vary in size. In this dissertation, two multi-scale object-based classification methods were developed and tested for classifying high resolution images of Deerfield Beach, FL and Houston, TX. These multi-scale methods achieved higher overall classification accuracies and Kappa coefficients than single-scale object-based classification methods. / Since the two dissertation methods used an automated algorithm (Random Forest) for image classification, they are also less subjective and easier to apply to other study areas than most existing multi-scale object-based methods that rely on expert knowledge (i.e. decision rules developed based on detailed visual inspection of image segments) for classifying each type of land cover. / by Brian A. Johnson. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Reliable geographic intelligence is essential for urban areas; land-cover classification creates the data for urban spatial decision making. This research tested a methodology to create a land-cover map for the main campus of Florida Atlantic University in Boca Raton, Florida. The accuracy of nine separate land-cover classification results were tested; the one with the highest accuracy was chosen for the final map. Object-based image segmentation was applied to fused and LiDAR point cloud (elevation and intensity) data and aerial imagery. These were classified by Random Forest, k-Nearest Neighbor and Support Vector Machines classifiers. Shadow features were reclassified hierarchically in order to create a complete map. The Random Forest classifier used with the fused data set gave the highest overall accuracy at 82.3%, and a Kappa value at 0.77. When combined with the results from the shadow reclassification, the overall accuracy increased to 86.3% and the Kappa value improved to 0.82. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Lin, Hualiang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 140-177). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

The microbial communities found in soils are inherently heterogeneous and often exhibit spatial variations on a small scale. Becker et al. (2006) investigate this phenomenon and present statistical analyses to support their findings. In this project, alternative statistical methods and models are considered and employed in a re-analysis of the data from Becker. First, parametric nested random effects models are considered as an alternative to the nonparametric semivariogram models and kriging methods employed by Becker to analyze patterns of spatial variation. Second, multiple logistic regression models are employed to investigate factors influencing microbial community structure as an alternative to the simple logistic models used by Becker. Additionally, the microbial community profile data of Becker were unobservable at several points in the spatial grid. The Becker analysis assumes that the data are missing completely at random and as such have relatively little impact on inference. In this re-analysis, this assumption is investigated and it is shown that the pattern of missingness is correlated with both metabolic potential and spatial coordinates and thus provides useful information that was previously ignored by Becker. Multiple imputation methods are employed to incorporate the information present in the missing data pattern and results are compared with those of Becker.

Made available in DSpace on 2017-05-12T14:47:11Z (GMT). No. of bitstreams: 1 Claudia Regina Hezel.pdf: 2628130 bytes, checksum: f776400a56686d4085b790f2d9436120 (MD5) Previous issue date: 2007-07-16 / In engineering it is always looked to construct resistant structures, safe and economically viable. The safe and economic project of the structures is function of the imposed actions; in the case of silos it does not have a Brazilian norm that it prescribes on its projects and action, moreover, some divergences are observed between the foreign norms. This main work as objective the comparative analysis of the lapsings of the international norms: ENV (1995), the 3774 (1996), ACI 313 (1991), DIN 1055 (1987) and BMHB (1985), becoming an analysis statistics between them, being elaborated an electronic spread sheet of calculation of the pressures, being able itself to vary the properties, to facilitate to the analysis and the development of an theoretician-experimental study. It still has as purpose to present a theoretical study of the pressures in vertical silos, for this, a state of the art of the theories of pressures proposals for the most important researchers was developed and finally the modeling of a silo to be analyzed through Ansys® software. The comparative analysis statistics of the main foreign norms showed the existence of sufficiently significant differences between the gotten values, being that in the case of the horizontal pressures it has differences of up to 59% (between norm BMHB and DIN) and that in the average the lesser values are gotten in the British and the greaters in the German. It was still verified that the majority of the foreign norms adopts the theory of Janssen for the determination of the horizontal pressures. In relation to the vertical pressures, the difference between the norms arrived 400% almost (between norms ENV and), in average the lesser values is gotten in the European norm and the greaters in the Australian, were still observed that the model of Janssen, without no alteration are considered by norm ACI. E in the case of the pressures of attrition with the wall the lesser values are gotten in norm BMHB and the greaters in the DIN, having arrived themselves it 59% differences (between norm BMHB and DIN). In relation to the use of the Ansys® program an initial plan of modeling of a silo was sketched, observing itself that the program and the methodology are useful, being able itself to make a refinement, to compare the results and to vary the in agreement pressure the diverse existing norms, being able to be developed in a future work, becoming a comparative degree between practical theoretician and with silo use archetype and cells of pressure. / Na engenharia, procura-se sempre construir estruturas resistentes, seguras e economicamente viáveis. O projeto seguro e econômico das estruturas é função das ações impostas; no caso de silos, não há uma norma brasileira que prescreva sobre seus projetos e ações, além disso, algumas divergências são observadas entre as normas estrangeiras. Este trabalho tem como objetivo principal a análise comparativa das prescrições das normas internacionais: ENV (1995), AS 3774 (1996), ACI 313 (1991), DIN 1055 (1987) e BMHB (1985), fazendo-se uma análise estatística entre elas, sendo elaborada uma planilha eletrônica de cálculo das pressões, podendo-se variar as propriedades, facilitar a análise e o desenvolvimento de um estudo teórico-experimental. Tem ainda como finalidade apresentar um estudo teórico das pressões em silos verticais, para isso, um estado da arte das teorias de pressões propostas pelos mais importantes pesquisadores foi desenvolvido e por último a modelagem de um silo para ser analisado através do software Ansys®. A análise comparativa estatística das principais normas estrangeiras mostrou a existência de diferenças bastante significativas entre os valores obtidos, sendo que no caso das pressões horizontais há diferenças de até 59% (entre norma BMHB e DIN) e que na média os menores valores são obtidos na Britânica e os maiores na Alemã. Verificou-se ainda que a maioria das normas estrangeiras adota a teoria de Janssen para a determinação das pressões horizontais. Em relação às pressões verticais, a diferença entre as normas chegou a quase 400% (entre normas ENV e AS), em média os menores valores são obtidos na norma Européia e os maiores na Australiana, observou-se ainda que o modelo de Janssen, sem nenhuma alteração é proposto pela norma ACI. E no caso das pressões de atrito com a parede os menores valores são obtidos na norma BMHB e os maiores na DIN, chegando-se a diferenças de 59% (entre norma BMHB e DIN). Em relação ao uso do programa Ansys® esboçou-se um plano inicial de modelagem de um silo, observando-se que o programa e a metodologia são úteis, podendo-se fazer um refinamento, comparar os resultados e variar a pressão conforme as diversas normas existentes, podendo ser desenvolvido em um trabalho futuro, fazendo-se um comparativo entre teórico e prático com uso de silo protótipo e células de pressão.

Abstract not available

Dans ce manuscrit, nous illustrons les concepts de capillarité et de métastabilité avec des exemples mettant en jeu surtout l'hélium ou l'eau. L'étude de liquides métastables peut apporter des informations originales sur leur structure. Dans le cas de l'eau, nous avons mesuré à quel degré le liquide pouvait être porté au-delà de l'équilibre avec la vapeur : nous avons ainsi exploré la région des pressions négatives, où le liquide est mis sous tension mécanique, à densité réduite. Nos résultats indiquent une nouvelle anomalie de l'eau dans cette région. Dans l'hélium, nous avons exploré une autre sorte de métastabilité, cette fois en appliquant une pression supérieure à la pression de cristallisation : le liquide devient plus dense et métastable comparé au solide. Cela soulève des questions intéressantes à propos du maintien de la superfluidité. Tout d'abord, nous nous intéressons à la capillarité, en portant une attention particulière à l'interface liquide-solide de l'hélium et à l'interface liquide-vapeur de l'eau. Nous présentons également quelques éléments concernant l'adsorption dans des pores. Ensuite nous discutons la métastabilité d'un point de vue théorique ; nous donnons une relation quantitative avec la capillarité et faisons le lien entre la cavitation et certaines anomalies de l'hélium et de l'eau. Nous traitons aussi des propriétés quantiques de l'hélium métastable et faisons une brève digression à propos de la nucléation en géométrie confinée. Enfin, nous récapitulons nos expériences sur la cavitation dans l'eau et la cristallisation dans l'hélium, basées sur la même technique acoustique.

Nous passons en revue certains résultats obtenus dans quatre thèmes: les équations de Navier-Stokes stochastiques en deux dimensions, la loi de Fourier dans les chaines d'oscillateurs anharmoniques, les grandes déviations de ces systèmes et finalement, les dynamiques de collision locales.

Ce manuscrit présente une étude des cinétiques de réactions ligand-récepteur sur des surfaces en regard, fondée sur l'utilisation de particules magnétiques colloïdales. Notre démarche repose sur la mesure de cinétiques de formation de doublets indépendants de particules, déclenchée par l'application d'un champ magnétique. Ces mesures sont directement reliées aux constantes cinétiques du couple ligand-récepteur à la surface des particules magnétiques. En considérant le couple streptavidine-biotine, nous avons validé notre approche et mis en évidence une source de variabilité des constantes d'association en surface : le degré de confinement des réactifs sur les surfaces. Pour les configurations les plus rapides, nous avons appréhendé la constante d'association comme limitée par des processus de diffusion, associés à la dynamique des particules colloïdales. Pour les configurations les plus lentes, où les réactifs sont les plus confinés en surface, le ralentissement observé est attribué à une diminution de l'efficacité des rencontres entre réactifs. Nous avons également étudié la cinétique d'association entre cadhérines, molécules directement impliquées dans l'adhésion cellulaire. Nous avons mis en évidence l'influence des conditions de contact sur l'état d'adhésion entre cadhérines. Pour les deux états d'adhésion « profonds » observés, nous avons mesuré une constante cinétique d'association plus lente que celle de l'interaction streptavidine-biotine.

Dans le domaine du Chaos Ondulatoire, les statistiques des systèmes fermés sont à l'heure ac- tuelle bien comprises. Cependant, il en est tout autrement pour les systèmes ouverts, c'est-à-dire pour des systèmes dont le couplage avec l'environnement ne peut plus être négligé. En appli- quant la Théorie des Matrices Aléatoires au formalisme de l'hamiltonien effectif, les statistiques spectrales et spatiales de systèmes chaotiques ouverts sont étudiées analytiquement. De plus, les prédictions théoriques sont systématiquement vérifiées par des simulations numériques de type matrices aléatoires. Dans le domaine spectral, les modifications engendrées par le couplage sur les écarts et les croisements évités sont illustrées par le phénomène de piégeage des résonances. Les distributions bien connues des écarts et des croisements évités sont généralisées aux systèmes chaotiques ouverts, permettant d'expliquer des résultats expérimentaux obtenus avec une cavité électromagnétique. Dans le domaine spatial, les statistiques du paramètre de non-orthogonalité, qui mesure l'effet du couplage sur les fonctions d'onde propres de l'hamiltonien effectif, sont dérivées analytiquement et sont vérifiées par des simulations numériques modélisant des cavités électromagnétiques chaotiques. Pour des systèmes dont le couplage varie, une relation entre la largeur spectrale et le paramètre de non-orthogonalité associés à une même résonance est aussi obtenue. Cette prédiction est confirmée par des expériences en élastodynamique.