Dissertations / Theses on the topic 'Geodesic structure'

From Birkoff's theorem, the geometry in four spacetime dimensions outside a spherically symmetric and static, gravitating source must be given by the Schwarzschild metric. This metric therefore satisfies the Einstein vacuum equations. If the mass which gives rise to the Schwarzschild spacetime geometry is concentrated within a radius of r=2M, a black hole will form. Non-accelerating particles (freely falling) traveling through this geometry will do so along parametrized curves called geodesics, which are curved space generalizations of straight paths. These geodesics can be found by solving the geodesic equation. In this thesis, the geodesic structure in the Schwarzschild geometry is investigated with an attempt to generalize the solution to higher dimensions.

[No abstract supplied with this thesis - The first page (of three) of the Introduction follows] ¶ This thesis is largely concerned with the changing representations of 'boundary' or 'ideal' points of a pseudo-Riemannian manifold -- and our primary interest is in the space-times of general relativity. In particular, we are interested in the following question: What assumptions about the 'nature' of 'portions' of a certain 'ideal boundary' construction (essentially the 'abstract boundary' of Scott and Szekeres (1994)) allow us to define precisely the topological type of these 'portions', i.e., to show that different representations of this ideal boundary, corresponding to different embeddings of the manifold into others, have corresponding 'portions' that are homeomorphic? ¶ Certain topological properties of these 'portions' are preserved, even allowing for quite unpleasant properties of the metric (Fama and Scott 1995). These results are given in Appendix D, since they are not used elsewhere and, as well as representing the main portion of work undertaken under the supervision of Scott, which deserves recognition, may serve as an interesting example of the relative ease with which certain simple results about the abstract boundary can be obtained. ¶ An answer to a more precisely formulated version of this question appears very diffcult in general. However, we can give a rather complete answer in certain cases, where we dictate certain 'generalised regularity' requirements for our embeddings, but make no demands on the precise functional form of our metrics apart from these. For example, we get a complete answer to our question for abstract boundary sets which do not 'wiggle about' too much -- i.e., they satisfy a certain Lipschitz condition -- and through which the metric can be extended in a manner which is not required to be differentiable (C[superscript1]), but is continuous and non--degenerate. We allow similar freedoms on the interior of the manifold, thereby bringing gravitational wave space-times within our sphere of discussion. In fact, in the course of developing these results in progressively greater generality, we get, almost 'free', certain abilities to begin looking at geodesic structure on quite general pseudo-Riemannian manifolds. ¶ It is possible to delineate most of this work cleanly into two major parts. Firstly, there are results which use classical geometric constructs and can be given for the original abstract boundary construction, which requires differentiability of both manifolds and metrics, and which we summarise below. The second -- and significantly longer -- part involves extensions of those constructs and results to more general metrics.

The diploma thesis covers a design and an assesment of a timber bearing structure of sports hall. The plan of the hall is round, i.e. the object is shaped as a dome. The structure is designed in two ways: geodesic and ribbed dome. Both options are made of glued laminated timber and structural timber.

Ce travail étudie les variétés pseudo-riemanniennes compactes localement homogènes à travers le prisme des (G,X)-structures, introduites par Thurston dans son programme de géométrisation. Nous commençons par présenter la problématique générale et discutons notamment du rapport entre la complétude géodésique de ces variétés et une autre notion de complétude propre aux (G,X)-structures. Nous donnons également dans le chapitre 1 une nouvelle preuve d’un théorème de Bromberg et Medina qui classifie les métriques lorentziennes invariantes à gauche sur SL(2,R) dont le flot géodésique est complet. Conjecturalement, toute (G,X)-structure pseudo-riemannienne sur une variété compacte est complète. Nous prouvons ici que cela est vrai pour certaines géométries, sous l’hypothèse que la (G,X)-structure est a priori kleinienne. On en déduit que, pour ces géométries, la complétude est une condition fermée. Lorsque X est un groupe de Lie de rang 1 muni de sa métrique de Killing, ce résultat complète un théorème de Guéritaud–Guichard–Kassel–Wienhard selon lequel la complétude est une condition ouverte. Nous nous tournons ensuite vers l’étude des représentations d’un groupe de surface à valeurs dans les isométries d’une variété riemannienne M complète simplement connexe de courbure sectionnelle inférieure à -1. Étant donnée une telle représentation ρ, nous montrons que l’ensemble des représentations fuchsiennes j telles qu’il existe une application (j,ρ)-équivariante et contractante de H2 dans M est un ouvert non vide et contractile de l’espace de Teichmüller (sauf lorsque ρ est elle-même fuchsienne). Ce résultat nous permet de décrire l’espace des métriques lorentziennes de courbure constante -1 sur un fibré en cercle au-dessus d’une surface compacte. Nous montrons que cet espace possède un nombre fini de composantes connexes classifiées par un invariant que nous appelons longueur de la fibre. Nous prouvons également que le volume total de ces métriques ne dépend que de la topologie du fibré et de la longueur de la fibre
In this work, we study closed locally homogeneous pseudo-Riemannian manifolds through the notion of (G,X)-structure, introduced by Thurston in his geometrization program. We start by presenting the general problem. In particular, we discuss the link between geodesical completeness of those manifolds and another notion of completeness specific to (G,X)-structures. In chapter 1, we also give a new proof of a theorem by Bromberg and Medina which classifies left invariant Lorentz metrics on SL(2,R) that are geodesically complete. Conjecturally, every pseudo-riemannian (G,X)-structure on a closed manifold is complete. Here we prove that it holds for certain geometries, provided that the (G,X )-structure is a priori Kleinian . This implies that, for such geometries, completeness is a closed condition. When X is a Lie group of rank 1 handled with its Killing metric, this result complements a theorem of Guéritaud–Guichard–Kassel–Wienhard, acording to which completeness is an open condition. We then turn to the study of representations of surface groups into the isometry group of a complete simply connected Riemannian manifold M of curvature less than or equal to -1. Given such a representation ρ, we prove that the set of Fuchsian representations j for which there exists a (j,ρ)-equivariant contracting map from H2 to M is a non-empty open contractible subset of the Teichmüller space (unless ρ itself is Fuchsian). This result allows us to describe the space of Lorentz metrics of constant curvature -1 on a circle bundle over a closed surface. We show that this space has finitely many connected components, classified by an invariant that we call the length of the fiber. We also prove that the total volume of those metrics only depends on the topology of the bundle and on the length of the fiber

Cette thèse est consacrée à l’étude du problème de transport de Monge pour le coût quadratique en géométrie sous-Riemannienne et des conditions essentielles à l’obtention des résultats d’existence et et d’unicité de solutions. Ces travaux consistent à étendre ces résultats au cas des structures sous-Riemanniennes admettant des géodésiques minimisantes singulières. Dans une première partie, on développe des techniques inspirées de travaux de Cavalletti et Huesmann pour d’obtenir des résultats significatifs pour des structures de rang 2 en dimension 4. Dans une deuxième partie, on étudie des outils analytiques de la h-semiconcavité de la distance sousriemannienne et on montre comment ce type de régularité peut aboutit à l’obtention d’existence et d’unicité de solutions dans un cas général
This thesis is devoted to the study of the Monge transport problem for the quadratic cost in sub-Riemannian geometry and the essential conditions to obtain existence and uniqueness of solutions. These works consist in extending these results to the case of sub-Riemannian structures admitting singular minimizing geodesics. In a first part, we develop techniques inspired by works by Cavalletti and Huesmann in order to obtain significant results for structures of rank 2 in dimension 4. In a second part, we study analytical tools of the h-semiconcavity of the sub-Riemannian distance and we show how this type of regularity can lead to the well-posedness of the Monge problem in general cases

Three-dimensional mapping and modeling can contribute to knowledge about the real world. Techniques are largely driven by available technology and typically involve expensive equipment and expert skill. Recent advances have led to low-cost remotely sensed data collection and generation of 3D terrain models using Uninhabited Aerial Vehicles (UAV) and Structure from Motion (SfM) processing software. This research presents a low-cost alternative to 3D mapping by pairing UAV collection methods with three SfM processing techniques. Surface models are generated from the same image set captured from a low-cost UAV coupled with a digital camera. Accuracy of resulting models identifies strengths and weaknesses of each technique. Analysis of different slope ranges investigates the divide at which surfaces generated become less reliable. This research provides a deeper understanding of the strengths and limitations of emerging technologies used together in a fresh approach to photogrammetry.

A monitoração dinâmica de pontes rodoviárias através da determinação de deslocamentos espaciais é uma das atuais áreas de interesse da geodésia. A tecnologia de posicionamento por satélite é uma das ferramentas disponíveis para este fim e foi avaliada nesta pesquisa. Verifica-se que o GNSS pode contribuir para com o monitoramento dinâmico de estruturas e nos últimos anos se observam aplicações em grandes pontes estaiadas na Ásia, na Europa e na América do Norte. No presente estudo analisou-se a aplicação desta tecnologia em uma estrutura mais rígida, sob vinculo com uma rede de referência única e sob as condições apresentadas pela região brasileira. Foram realizados ensaios em um shaker, na Base de Calibração de Instrumentos Geodésicos da USP e na estrutura do Viaduto Ascendente 19 da rodovia dos Imigrantes, empregando-se a tecnologia GPS e análise modal. A partir de determinações no método relativo cinemático obtiveram-se os deslocamentos tridimensionais e a freqüências do primeiro modo de vibração da estrutura. A metodologia aplicada e os resultados obtidos demonstram a potencialidade do método também para estruturas mais rígidas e sob condições características da região brasileira, que diferem de outras partes do globo no que tange a tecnologia GPS. Ao final é sugerida uma Proposta Básica de Metodologia para a Monitoração de Estrutura com Carga Dinâmica pela Utilização de GNSS.
The dynamic monitoring of road bridges though spatial displacements is one of the geodetic areas of interests. The satellite positioning technologies are one of the disposed tools for this task and were evaluate by present research. One verifies that GNSS can contribute for the dynamic monitoring of structures, and has applied for this task in the last years to large cable stayed bridges on Asia, on Europe and on North America. On the present study, one analyses the use of this technology in a more rigid structure, tied to a unique reference network and under Brazilian region conditions. Were realized essays over a shaker on USP Geodetic Instrumental Calibration Base and over the Imigrantes Roadway Ascending Viaduct 19 employing the GPS technology and modal analysis. By determinations in the kinematics relative method ones obtain the tridimensional displacements and the frequency of first modal shape of the structure. The applied methodology and its obtained results demonstrate the potentiality of this method for more rigid structure too, and under Brazilian region characteristics. At the end is proponed a Methodological Basic Proposal for Dynamic Charged Structure Monitoring thru GNSS Employment.

Dans les domaines de l’imagerie médicale et de la vision par ordinateur, la segmentation joue un rôle crucial dans le but d’extraire les composantes intéressantes d’une image ou d’une séquence d’images. Elle est à l’intermédiaire entre le traitement d’images de bas niveau et les applications cliniques et celles de la vision par ordinateur de haut niveau. Ces applications de haut niveau peuvent inclure le diagnostic, la planification de la thérapie, la détection et la reconnaissance d'objet, etc. Parmi les méthodes de segmentation existantes, les courbes géodésiques minimales possèdent des avantages théoriques et pratiques importants tels que le minimum global de l’énergie géodésique et la méthode bien connue de Fast Marching pour obtenir une solution numérique. Dans cette thèse, nous nous concentrons sur les méthodes géodésiques basées sur l’équation aux dérivées partielles, l’équation Eikonale, afin d’étudier des méthodes précises, rapides et robustes, pour l’extraction de structures tubulaires et la segmentation d’image, en développant diverses métriques géodésiques locales pour des applications cliniques et la segmentation d’images en général
In the fields of medical imaging and computer vision, segmentation plays a crucial role with the goal of separating the interesting components from one image or a sequence of image frames. It bridges the gaps between the low-level image processing and high level clinical and computer vision applications. Among the existing segmentation methods, minimal geodesics have important theoretical and practical advantages such as the global minimum of the geodesic energy and the well-established fast marching method for numerical solution. In this thesis, we focus on the Eikonal partial differential equation based geodesic methods to investigate accurate, fast and robust tubular structure extraction and image segmentation methods, by developing various local geodesic metrics for types of clinical and segmentation tasks. This thesis aims to applying different geodesic metrics based on the Eikonal framework to solve different image segmentation problems especially for tubularity segmentation and region-based active contours models, by making use of more information from the image feature and prior clinical knowledges. The designed geodesic metrics basically take advantages of the geodesic orientation or anisotropy, the image feature consistency, the geodesic curvature and the geodesic asymmetry property to deal with various difficulties suffered by the classical minimal geodesic models and the active contours models. The main contributions of this thesis lie at the deep study of the various geodesic metrics and their applications in medical imaging and image segmentation. Experiments on medical images and nature images show the effectiveness of the presented contributions

Riparian vegetation restoration efforts demand cost effective, accurate, and replicable impact assessments. In this thesis a method is presented using an Unmanned Aerial Vehicle (UAV) equipped with a GoPro digital camera to collect photogrammetric data of a 2.02-acre riparian restoration. A three-dimensional point cloud was created from the photos using Structure from Motion (SfM) techniques. The point cloud was analyzed and compared to traditional, ground-based monitoring techniques. Ground truth data collected using the status-quo approach was collected on 6.3% of the study site and averaged across the entire site to report stem heights in stems/acre in three height classes, 0-3 feet, 3-7 feet, and greater than 7 feet. The project site was divided into four analysis sections, one for derivation of parameters used in the UAV data analysis, and the remaining three sections reserved for method validation. The most conservative of several methods tested comparing the ground truth data to the UAV generated data produced an overall error of 21.6% and indicated an r² value of 0.98. A Bland Altman analysis indicated a 99% probability that the UAV stems/plot result will be within 159 stems/plot of the ground truth data. The ground truth data is reported with an 80% confidence interval of +/- 844 stems/plot, thus the UAV was able to estimate stems well within this confidence interval. Further research is required to validate this method longitudinally at this same site and across varying ecologies. These results suggest that UAV derived environmental impact assessments at riparian restoration sites may offer competitive performance and value.

The design of several variants of the structure of the planetarium in Brno is the subject of the diploma thesis . The building has a ground plan size of 30x30 meters. The main supporting material is S235 steel. The bearing structure of the object consists of columns, joists and beams. The bearing structure of the dome consists of a spatial structure, which is formed as a half-globe above the diameter of 18 meters. 3 versions of this dome have been processed. The resulting design is Geodetic Dome. Part of the work is an assessment of the main structural elements and selected details. The Scia engineer 2016 version 16.1.3033 was used to calculate internal forces.

In Iceland, glaciers cover approximately 11% of the land surface and comprise the country's largest reservoir of freshwater. Increases in summer temperatures since the mid-1980s have led to rapid mass loss from the Icelandic ice caps of 9.5-11.4 Gt/yr, and continuously operating GPS stations nationwide have recorded rapid and accelerating surface uplift. Understanding the behavior of Icelandic ice caps-and their relationship to surface uplift, which is modulated by the rheological structure of the crust and upper mantle-has important implications for water resource management and geohazards analysis. The goals of this study are twofold. First, we aim improve the current estimates of glacial isostatic adjustment (GIA)-related uplift in Iceland and to examine if and how uplift rates have changed over the last several decades. Secondly, we explore the utility of motion recorded by continuously operating Global Positioning System stations (cGPS) as an independent measure of ice cap mass variation over both decadal and annual time scales. We take advantage of the now longstanding cGPS network in Iceland and consider position time series from 62 stations across the entire island. Observations made by cGPS stations from 1995-2014.7 show a broad region of rapid uplift in central Iceland with near zero uplift observed along the coastal regions to the north and west. The most rapid uplift and uplift accelerations occur near the center of the island, between the Vatnajökull and Hofsjökull ice caps, with rates exceeding 30 mm/yr and accelerations of 1-2 mm/yr². Statistically significant uplift and uplift accelerations are recorded at 27 of the 62 cGPS stations, and estimates for the timing of uplift initiation correlate with Arctic warming trends and observations of increasing summer temperatures since the mid-1980s. These results represent a significant improvement over previous uplift estimates and indicate a likely relationship between accelerated ice cap melting and contemporaneous changes in uplift rates. Incorporating cGPS-recorded information about modern-day uplift rates affects estimates of mantle viscosity. Ice cap thinning rates are computed by a weighted least squares estimation scheme utilizing cGPS-derived secular uplift rates and accelerations and Green's functions for an elastic layer over a Maxwell viscoelastic half-space. We test a range of viscosities from 8 x 10¹⁷ and 1 x 10²⁰ Pa·s and find that thinning rates computed with low viscosities between 2 x 10¹⁸ and 1 x 10¹⁹ Pa·s match independently derived ice cap thinning rates best, in accordance with previous upper mantle viscosity estimates. Similar estimation techniques demonstrate the utility of cGPS to provide a seasonal mass variation time series as a potential low-cost compliment to traditional field-based mass balance measurements. We use estimates of secular site velocity and acceleration to reduce the time series and focus only on the annual periodic motion. The increased temporal resolution afforded by the daily cGPS position estimates recovers the interannual variability in the timing and magnitude of accumulation and melt seasons with a small RMS reduction relative to a sinusoidal model. We also find we are able to identify of the effects of both ice cap insulation as well as reduced surface albedo following volcanic eruptions.

A segurança dos empreendimentos civis tem se tornado fator preponderante na viabilidade econômica das obras, uma vez que impacta o preço dos seguros cobrados. Dentro deste contexto, um dos aspectos importantes a serem considerados na elaboração de um projeto, notadamente no de grandes estruturas, é a instrumentação. Assim, ao se tratar com grandes barragens, a concatenação da instrumentação civil com a geodésica se faz necessária. Um dos métodos geodésicos utilizados para a verificação da estabilidade de uma estrutura é a ressecção, que consiste na medição das distâncias entre as estações de referência, com coordenadas conhecidas e estáveis, e os alvos. Esta medição pressupõe, também, a intervisibilidade entre as estações de referência e entre conjuntos estações de referência-alvos. Assim, as estações devem ser instaladas nas proximidades da barragem e sobre rocha sã, fora do polígono de deformação previsto para o substrato rochoso, o que nem sempre é possível. Dessa forma, a metodologia GNSS, por não necessitar de intervisibilidade entre quaisquer estações, é aplicável mesmo que a ocorrência de rocha aflorada e sã seja afastada da barragem, não importando se a montante ou a jusante. A pesquisa pretende provar a compatibilidade entre as medições realizadas por ressecção e GNSS; provando, assim, a viabilidade da utilização do GNSS para o monitoramento de barragens, independentemente da solução estrutural adotada
The security of the civil undertakings has become predominant factor in the economical viability of the enterprises, because it impacts the price of the collected insurances. Inside this context, one of the important aspects that are being considered in the preparation of a project, especially in that of great structures, is the instrumentation. So, while negotiating with great dams, the concatenation of the civil instrumentation with the geodetic one is made necessary. One of the geodetic methods used for the checking of the stability of a structure is the resection, which consists of the measurement of the distances between the stations of reference, with known and stable coordinates, and the targets. This measurement presupposes, also, the intervisibility between the stations of reference and between sets stations of white-reference. So, the stations must be installed in the proximities of the dam and on healthy rock, out of the polygon of deformation predicted for the rocky substrate, which not always is possible. In this form, because of not needing intervisibility between any stations, the methodology GNSS is applicable same that the incident of emerged and healthy rock is removed of the dam, not mattering if to amount or downstream. The inquiry intends to prove the compatibility between the measurements carried out by resection and GNSS; proving, so, the viability of the use of the GNSS for the monitorament of dams, independently of the structural adopted solution

Home…that space so personal, so distinct, so intrinsic to the human/place relationship that “lies right at the heart of human geography” (Cresswell, 2004, p. 93). Studying the connection people feel toward certain places through concepts of emotion, experience, and attachment to meaning stems outward from the phenomenological and humanist branches of geography (Holt-Jensen, 2009). With every person’s version of home a space unto itself, is it possible for a place so intimate to be studied and defined? My answer is yes. This phenomenological case study investigates the perceptions and emotions of a newly designated conservation neighborhood, the second of its kind in Reno, Nevada. In an area usually looked at as a site for economic development and perhaps initiatives in historic preservation, there is little research undertaken through a cultural geographic lens aiming to understand how different communities in the area view their own home ground in transition and the implications of place creation. This project navigates the allegory of home through the voices and drawn maps of the Wells Avenue Neighborhood Conservation District (WANCD) and is approached through the impressions and attitudes of community groups, merchants, and a patchwork of residents diverse in both their backgrounds and their stories about the place they live. Through the construction of sense of place inside and around the WANCD and with the usage of Geographic Information Systems as a tool for qualitative data collection and comunication, this study investigates how personal experiences and perceptions, community connections and common goals, and specifically-identified areas of personal meaning play into the way in which these different stakeholders experience, participate in, and envision their neighborhood.

Understanding spatial and temporal variations in strain accumulation and release along plate boundaries is a fundamental problem in tectonics. Short-term and long-term slip rates are expected to be equal if the regional stress field remains unchanged over time, yet discrepancies between modern geodetic (decadal time scale) slip rates and long-term geologic (10^3 to 10^6 years) slip rates have been observed on parts of the Pacific-North American plate boundary system. Contemporary geodetic slip rates are observed to be ~2 times greater than late Pleistocene geologic slip rates across the southern Walker Lane. I use a combination of GPS geodesy, detailed field geologic mapping, high-resolution LiDAR geodetic imaging, and terrestrial cosmogenic nuclide geochronology to investigate the observed discrepancy between long- and short-term slip rates. I find that the present day slip rate derived from GPS geodesy across the Walker Lane at ~37.5°N is 10.6 ± 0.5 mm/yr. GPS data suggest that much of the observed discrepancy occurs west of the White Mountains fault zone. New dextral slip rates on the White Mountains fault zone of 1.1 ± 0.1 mm/yr since 755 ka, 1.9 +0.5/-0.4 mm/yr since 75-115 ka, 1.9 +0.5/-0.4 mm/yr since 38.4 ± 9.0 ka, and 1.8 +2.8/-0.7 mm/yr since 6.2 ± 3.8 ka are significantly faster than previous estimates and suggest that slip rates there have remained constant since the middle Pleistocene. On the Lone Mountain fault I calculate slip rates of 0.8 ± 0.1 mm/yr since 14.6 ± 1.0 ka and 0.7 ± 0.1 mm/yr since 8.0 ± 0.5 ka, which suggest that extension in the Silver Peak-Lone Mountain extensional complex has increased dramatically since the late Pleistocene.

Cette thèse est divisée en trois parties. Dans la première, on étudie des systèmes articulés (mécanismes formés de tiges rigides) dont l'espace ambiant n'est pas le plan, mais diverses variétés riemanniennes. On étudie la question de l'universalité des mécanismes : cette notion correspond à l'idée que toute courbe serait tracée par un sommet d'un mécanisme, et que toute variété différentiable serait l'espace de configuration d'un mécanisme. On étend les théorèmes d'universalité au plan de Minkowski, au plan hyperbolique et enfin à la sphère.Toute surface dans R^3 peut être aplatie selon l'axe des z, et la surface aplatie s'approche d'une table de billard dans R^2. Dans la seconde partie, on montre que, sous certaines hypothèses, le flot géodésique de la surface converge localement uniformément vers le flot de billard. De plus, si le billard est dispersif, les propriétés chaotiques du billard remontent au flot géodésique : on montre qu'il est alors Anosov. En appliquant ce résultat à la théorie des systèmes articulés, on obtient un nouvel exemple de systèmes articulé Anosov, comportant cinq tiges.Dans la troisième partie, on s'intéresse aux variétés munies de connexions localement métriques, c'est-à-dire de connexions qui sont localement des connexions de Levi-Civita de métriques riemanniennes ; on donne dans ce cadre un analogue du théorème de décomposition de De Rham, qui s'applique habituellement aux variétés riemanniennes. Dans le cas où une telle connexion préserve une structure conforme, on montre que cette décomposition comporte au plus deux facteurs ; de plus, lorsqu'il y a exactement deux facteurs, l'un des deux est l'espace euclidien R^q. La démonstration des résultats de cette partie passe par l'étude des feuilletages munis d'une structure de similitude transverse. Sur ces feuilletages, on montre un résultat de rigidité qui peut être vu indépendamment des autres: ils sont soit transversalement plats, soit transversalement riemanniens
This thesis is divided into three parts. In the first part, we study linkages (mechanisms made of rigid rods) whose ambiant space is no longer the plane, but various Riemannian manifolds. We study the question of the universality of linkages: this notion corresponds to the idea that every curve would be traced out by a vertex of some linkage, and that any differentiable manifold would be the configuration space of some linkage. We extend universality theorems to the Minkowski plane, the hyperbolic plane, and finally the sphere.Any surface in R^3 can be flattened with respect to the z-axis, and the flattened surface gets close to a billiard table in R^2. In the second part, we show that, under some hypotheses, the geodesic flow of the surface converges locally uniformly to the billiard flow. Moreover, if the billiard is dispersing, the chaotic properties of the billiard also apply to the geodesic flow: we show that it is Anosov in this case. By applying this result to the theory of linkages, we obtain a new example of Anosov linkage, made of five rods.In the third part, we first consider manifolds with locally metric connections, that is, connections which are locally Levi-Civita connections of Riemannian metrics; we give in this framework an analog of De Rham's decomposition theorem, which usually applies to Riemannian manifolds. In the case such a connection also preserves a conformal structure, we show that this decomposition has at most two factors; moreover, when there are exactly two factors, one of them is the Euclidean space R^q. The proofs of the results of this part use foliations with transverse similarity structures. On these foliations, we give a rigidity theorem of independant interest: they are either transversally flat, or transversally Riemannian

L'objectif de cette thèse était de caractériser la déformation récente, tant dans son style que dans son partitionnement, d'un arc orogénique lent à travers une approche pluridisciplinaire à grande échelle.La déformation récente et actuelle de l'arc du Jura a été caractérisée par l'analyse des indices géomorphologiques le long des profils de rivières ainsi qu'à travers le traitement des données sismiques et géodésiques. Les essais de caractérisation et de datation des évènements tectoniques et sismiques à travers l'analyse des failles décrochantes tardives et des enregistrements spéléologiques n'ont pas permis d'apporter de nouvelles données sur la néotectonique du Jura. Cependant la combinaison des données et observations géomorphologiques, géophysiques et géodésiques confrontée aux données des précédentes études nous permets de proposer un modèle de répartition de la déformation dans le système orogénique Alpes occidentales-Jura. [...]
No abstract available

[ES] Esta tesis aborda el desarrollo de métodos de procesado y análisis de datos ALSFW para la caracterización de la estructura vertical del bosque y, en particular, del sotobosque. Para responder a este objetivo general, se establecieron seis objetivos específicos: En primer lugar, se analiza la influencia de la densidad de pulso, de los parámetros de voxelización (tamaño de vóxel y valor de asignación) y de los métodos de regresión sobre los valores de las métricas ALSFW y sobre la estimación de atributos de estructura del bosque. Para ello, se redujo aleatoriamente la densidad de pulsos y se modificaron los parámetros de voxelización, obteniendo los valores de las métricas ALSFW para las diferentes combinaciones de parámetros. Estas mismas métricas ALSFW se emplearon para la estimación de atributos de la estructura del bosque mediante diferentes métodos de regresión. En segundo lugar, se integran métodos de procesado y análisis de datos ALSFW en una nueva herramienta llamada WoLFeX (Waveform Lidar for Forestry eXtraction) que incluye los procesos de recorte, corrección radiométrica relativa, voxelización y extracción de métricas a partir de los datos ALSFW, así como nuevas métricas descriptoras del sotobosque. En tercer lugar, se evalúa la influencia del ángulo de escaneo utilizado en la adquisición de datos ALS y la corrección radiométrica en la extracción de métricas ALSFW y en la estimación de atributos de combustibilidad forestal. Para ello, se extrajeron métricas ALSFW con y sin corrección radiométrica relativa y empleando diferentes ángulos de escaneo. En cuarto lugar, se caracteriza la oclusión de la señal a lo largo de la estructura vertical del bosque empleando y comparando tres tipos diferentes de láser escáner (ALSFW, ALSD y láser escáner terrestre: TLS, por sus siglas en inglés), determinando así sus limitaciones en la detección de material vegetativo en dos ecosistemas forestales diferenciados: el boreal y el mediterráneo. Para cuantificar la oclusión de la señal a lo largo de la estructura vertical del bosque se propone un nuevo parámetro, la tasa de reducción del pulso, basada en el porcentaje de haces láser bloqueados antes de alcanzar una posición dada. En quinto lugar, se evalúa la forma en que se detectan y determinan las clases de densidad de sotobosque mediante los diferentes tipos de ALS. Se compararon los perfiles de distribución vertical en los estratos inferiores descritos por el ALSFW y el ALSD con respecto a los descritos por el TLS, utilizando este último como referencia. Asimismo, se determinaron las clases de densidad de sotobosque aplicando la curva Lorenz y el índice Gini a partir de los perfiles de distribución vertical descritos por ALSFW y ALSD. Finalmente, se aplican y evalúan las nuevas métricas ALSFW basadas en la voxelización, utilizando como referencia los atributos extraídos a partir del TLS, para estimar la altura, la cobertura y el volumen del sotobosque en un ecosistema mediterráneo.
[EN] This thesis addresses the development of ALSFW processing and analysis methods to characterize the vertical forest structure, in particular, the understory vegetation. To answer this overarching goal, a total of six specific objectives were established: Firstly, the influence of pulse density, voxel parameters (i.e., voxel size and assignation value) and regression methods on ALSFW metric values and on estimates of forest structure attributes are analyzed. To do this, pulse density was randomly reduced and voxel parameters modified, obtaining ALSFW metric values for the different parameter combinations. These ALSFW metrics were used to estimate forest structure attributes with different regression methods. Secondly, a set of ALSFW data processing and analysis methods are integrated in a new software named WoLFeX (Waveform Lidar for Forestry eXtraction), including clipping, relative radiometric correction, voxelization and ALSFW metric extraction, and proposing new metrics for understory vegetation. Thirdly, the influence of the scan angle of ALS data acquisition and radiometric correction on the extraction of ALSFW metrics and on modeling forest fuel attributes is assessed. To do this, ALSFW metrics were extracted applying and without applying relative radiometric correction and using different scan angles. Fourthly, signal occlusion is characterized along the vertical forest structure using and comparing three different laser scanning configurations (ALSFW, ALSD and terrestrial laser scanning: TLS), determining their limitations in the detection of vegetative material in two contrasted forest ecosystems: boreal and Mediterranean. To quantify signal occlusion along the vertical forest structure, a new parameter based on the percentage of laser beams blocked prior to reach a given location, the rate of pulse reduction, is proposed. Fifthly, the assessment of how understory vegetation density classes are detected and determined by different ALS configurations is done. Vertical distribution profiles at the lower strata described by ALSFW and ALSD are compared with those described by TLS as reference. Moreover, understory vegetation density classes are determined by applying the Lorenz curve and Gini index from the vertical distribution profiles described by ALSFW and ALSD. Finally, the new proposed voxel-based ALSFW metrics are applied and evaluated, using TLS-based attributes as a reference, to estimate understory height, cover and volume in a Mediterranean ecosystem.
[CA] Aquesta tesi aborda el desenvolupament de mètodes de processament i anàlisi de dades ALSFW per a la caracterització de l'estructura vertical del bosc i, en particular, del sotabosc. Per a respondre a aquest objectiu general, s'establiren sis objectius específics: En primer lloc, s'analitza la influència de la densitat de pols, dels paràmetres de voxelització (grandària de vóxel i valor d'assignació) i dels mètodes de regressió sobre els valors de les mètriques ALSFW i sobre l'estimació dels atributs d'estructura del bosc. Per a això, es reduí aleatòriament la densitat de polsos i es modificaren els paràmetres de voxelització, obtenint els valors de les mètriques ALSFW per a les diferents combinacions de paràmetres. Aquestes mètriques ALSFW s'empraren per a l'estimació d'atributs de l'estructura del bosc mitjançant diferents mètodes de regressió. En segon lloc, s'integraren mètodes de processament i d'anàlisi de dades ALSFW en una nova eina anomenada WoLFeX (Waveform Lidar for Forestry eXtraction) que inclou el processos de retallada, correcció radiomètrica relativa, voxelització i extracció de mètriques a partir de les dades ALSFW, així com noves mètriques descriptores del sotabosc. En tercer lloc, s'avalua la influència de l'angle de escaneig emprat en l'adquisició de les dades ALS i la correcció radiomètrica en l'extracció de mètriques ALSFW i en l'estimació d'atributs de combustibilitat forestal. Per a això, s'extragueren mètriques ALSFW amb i sense correcció radiomètrica relativa i emprant diferents angles d'escaneig. En quart lloc, es caracteritza l'oclusió del senyal al llarg de l'estructura vertical del bosc emprant i comparant tres tipus diferents de làser escàner (ALSFW, ALSD i làser escàner terrestre: TLS, per les seues sigles en anglès), determinant així les seues limitacions en la detecció de material vegetatiu en dos ecosistemes diferenciats: un boreal i un mediterrani. Per a quantificar l'oclusió del senyal al llarg de l'estructura vertical del bosc es proposa un nou paràmetre, la taxa de reducció del pols, basada en el percentatge de rajos làser bloquejats abans d'arribar a una posició donada. En cinquè lloc, s'avalua la manera en la qual es detecten i determinen les classes de densitat de sotabosc mitjançant els diferents tipus d'ALS. Es compararen els perfils de distribució vertical en estrats inferiors descrits per l'ALSFW i l'ALSD respecte als descrits pel TLS, emprant aquest últim com a referència. A més a més, es determinaren les classes de densitat de sotabosc aplicant la corba Lorenz i l'índex Gini a partir dels perfils de distribució vertical descrits per l'ALSFW i l'ALSD. Finalment, s'apliquen i avaluen les noves mètriques ALSFW basades en la voxelització, emprant com a referència els atributs extrets a partir del TLS, per a estimar l'alçada, la cobertura i el volum del sotabosc en un ecosistema mediterrani.
Crespo Peremarch, P. (2020). Processing and analysis of airborne fullwaveform laser scanning data for the characterization of forest structure and fuel properties [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153715
TESIS

Depuis le début du vingtième siècle, l’observation des variations de rotation de la Terre par les techniques astro-géodésiques permet de dévoiler les propriétés rhéologiques globales de la Terre. En particulier, les paramètres des modes d'oscillation libre de l'axe de rotation, qui sont aussi des paramètres de résonance - reflètent les défauts d'élasticité de la Terre solide, la réponse de l’océan au forçage externe et les propriétés de la graine fluide, éventuellement du noyau solide. On peut obtenir de meilleures contraintes sur ces paramètres de résonance en confrontant le mouvement terrestre du pôle de rotation observé (mouvement du pôle) – et aussi la nutation en tant que mouvement du pôle en rétrograde diurne - à l’excitation modélisée qui le produit. Les propriétés rhéologiques de la Terre sont d'autant mieux déterminées que le mouvement du pôle (y compris dans la bande diurne) est observé précisément et l’excitation modélisée correctement. A l'heure actuelle, si la précision du mouvement du pôle est légèrement meilleure au delà de 2 jours, la meilleure reconstitution du forçage concerne la bande de nutation (la bande rétrograde diurne), car il est procède alors des marées gravimétriques luni-solaires, lesquelles sont modélisées avec une grande précision). C'est pourquoi notre travail est d'abord consacré à l'ajustement direct des composantes luni-solaires périodiques de la nutation à partir des retards du VLBI, puis à l'estimation des paramètres de résonances dans la fonction de transfert entre ces termes de nutation observés et ceux modélisés pour une terre rigide, lesquels reflètent le forçage luni-solaire. Les résultats obtenus confirme notamment le raccourcissement d’environ 40-50 jours de la période de résonance du mouvement du pôle dans la bande rétrograde diurne. Nous montrons comment cette diminution s'explique par la réponse dynamique des océans à la marée du pôle, laquelle est étudiée à l'aune des modèles de marées océaniques diurnes . Nous prédisons également un changement des paramètres de résonance du mouvement du pôle à proximité de la fréquence de résonance de la nutation libre du noyau; cette modification semble confirmée par la détermination de ces paramètres à partir des termes de nutation. Notre étude des paramètres de résonance s'étend au delà de la bande de nutation. D'une part, nous réexaminons l’estimation des paramètres de résonance du mouvement du pôle dans la bande saisonnière, dominée par l’oscillation de Chandler, en utilisant les derniers modèles hydro-atmosphériques. D'autre part, nous étudions la résonance du mouvement du pôle à la bande prograde diurne, où l’excitation est dominée par la marée océanique. Nous obtenons une période de résonance de l’ordre de 393 jours, corroboré par notre modélisation fondée sur les modèles de marée océanique. L'ensemble des résultats obtenus permet d'apporter des contraintes sur la dépendance en fréquence du nombre de Love et du nombre de Love océanique caractérisant respectivement la réponse de la Terre solide et des océans à un potentiel externe de degré 2
Since the beginning of the 20th century, the observation of the Earth rotation variations through astro-geodetic techniques enables to investigate the global rheological properties of the Earth, in particular, the resonance parameters of the free rotation modes reflect the solid Earth anelasticity, the ocean response to an external forcing, and the properties of the fluid inner core, eventually of the solid inner core. Better constraints on these resonance parameters can be obtained by confronting the observed terrestrial motion of the rotation pole (the so-called polar motion) - including nutation as a retrograde diurnal polar motion - to the modelled excitation producing it. The more precise the modelled excitation and the observed polar motion are, the better the Earth rheological properties will be determined. For now, the best precision are reached in the nutation band. So, our work is first dedicated to a direct adjustment of the nutation components from VLBI delays, then the adjustment of the resonance parameters in the transfer function between the observed nutation terms and the corresponding rigid nutation terms that reflects the luni-solar forcing. The obtained resonance parameters confirms in particular the shortening of the polar motion resonance period of about 40 - 50 day in the retrograde diurnal band. Then, we show that the dynamical behaviour of the oceans in the diurnal band is mostly responsible for that. We also predicted a supplementary change of the resonance parameters in the vicinity of the free core nutation resonance, as expected from the solid Earth response, and confirmed by the adjustment of these parameters through the nutation terms. In addition to the nutation band, we revisit the estimation of the polar motion resonance parameters in the seasonal band, dominated by the Chandler wobble, in light of the most recent global circulation models of the hydro-atmospheric layers. Finally, we extend the investigation of polar motion resonance to the prograde diurnal polar motion, where the excitations mostly result from the ocean tides. We obtain a resonance period of about 393 days, and confirmed by our prediction based on the ocean tidal models. These results allow us to impose constraints on the frequency dependence of the body Love number and the Love number oceanic, characterizing respectively the response of the solid Earth and the oceans to an external potential of degree 2

Healthcare access is a highly reported problem for immigrant populations in the United States, especially for Hispanic migrants at the US-Mexico border. This statement holds particularly true for populations living in unincorporated communities known as colonias in the borderland region. Residents of a colonia are estimated to suffer from preventable or treatable illnesses including tuberculosis, hepatitis A, cholera, hypertension, type 2 diabetes, depression, substance abuse, among other health problems, at two to four times the national average (Matthiesen 1997; Anders et al. 2010:366; Mier et al. 2013:208; Sharkey et al. 2011; Davidhizar 1999). This apparent disparity is a result of unequal healthcare access due to social, legal, economic, and physical/spatial barriers. Using a structural violence framework as a lens, this study attempted to determine the barriers impeding access to healthcare for colonia residents, as well as analyze the interrelationships between the types of barriers. This study utilized semi-structured interviews to gain an understanding of perceived social, legal, spatial/physical, and other suggested barriers preventing healthcare access in El Paso County, TX colonias. In order to fully demonstrate the role of spatial/physical barriers on access to care, this study utilized Geographic Information Systems (GIS) to map obstacles in the targeted communities.

Nous définissons des formes normales géodésiques pour les séries générales des groupes de réflexions complexes G(de,e,n). Ceci nécessite l'élaboration d'une technique combinatoire afin de déterminer des décompositions réduites et de calculer la longueur des éléments de G(de,e,n) sur un ensemble générateur donné. En utilisant ces formes normales géodésiques, nous construisons des intervalles dans G(e,e,n) qui permettent d'obtenir des groupes de Garside. Certains de ces groupes correspondent au groupe de tresses complexe B(e,e,n). Pour les autres groupes de Garside, nous étudions certaines de leurs propriétés et nous calculons leurs groupes d'homologie sur Z d'ordre 2. Inspirés par les formes normales géodésiques, nous définissons aussi de nouvelles présentations et de nouvelles bases pour les algèbres de Hecke associées aux groupes de réflexions complexes G(e,e,n) et G(d,1,n) ce qui permet d'obtenir une nouvelle preuve de la conjecture de liberté de BMR (Broué-Malle-Rouquier) pour ces deux cas. Ensuite, nous définissons des algèbres de BMW (Birman-Murakami-Wenzl) et de Brauer pour le type (e,e,n). Ceci nous permet de construire des représentations de Krammer explicites pour des cas particuliers des groupes de tresses complexes B(e,e,n). Nous conjecturons que ces représentations sont fidèles. Enfin, en se basant sur nos calculs heuristiques, nous proposons une conjecture sur la structure de l'algèbre de BMW
We define geodesic normal forms for the general series of complex reflection groups G(de,e,n). This requires the elaboration of a combinatorial technique in order to determine minimal word representatives and to compute the length of the elements of G(de,e,n) over some generating set. Using these geodesic normal forms, we construct intervals in G(e,e,n) that give rise to Garside groups. Some of these groups correspond to the complex braid group B(e,e,n). For the other Garside groups that appear, we study some of their properties and compute their second integral homology groups. Inspired by the geodesic normal forms, we also define new presentations and new bases for the Hecke algebras associated to the complex reflection groups G(e,e,n) and G(d,1,n) which lead to a new proof of the BMR (Broué-Malle-Rouquier) freeness conjecture for these two cases. Next, we define a BMW (Birman-Murakami-Wenzl) and Brauer algebras for type (e,e,n). This enables us to construct explicit Krammer's representations for some cases of the complex braid groups B(e,e,n). We conjecture that these representations are faithful. Finally, based on our heuristic computations, we propose a conjecture about the structure of the BMW algebra

[EN] Hydric soil erosion is an economic and ecological problem throughout the world. Current investigation of the processes intervening in the erosion needs detailed information about the soil's surface topography appropriate in resolution and precision for the work's scale. Part of the studies trying to model and quantify the erosive processes are carried out in laboratories, in detailed scales (millimetric), and need methods capable of giving accurate measurements of the surface, in an efficient way. Experiments carried out in a laboratory to measure hydric erosion are based on the use of rain simulators on small soil plots. Soil's rugosity or micro relief influences considerably the distribution of rain water among infiltration and run-off, and is a key factor when modelling erosive processes. Accurate measurement of the plot's relief before and after the rain simulation allows estimation based on the volume differences. In recent years there is an increasing demand for accurate topographical data in the area of geomorphological science. Reproduction of the soil's surface is done by means of Digital Elevation Models (DEM), generated from massive altimetric data acquired by means of laser scanners or image-based photogrammetric techniques. These data have been collected by means of classical photogrammetric techniques (among others) up until recently; it is not, however, an easy task, and furthermore, to achieve the necessary accuracy, a strict methodology is needed, taking into account all the error sources in the process. Advances in digital photogrammetry and related fields, such as image processing and computer vision, have brought new software tools with potential application in various fields, such as geomorphology and erosion study. Structure from Motion (SfM) method produces automatically a 3D model of an object from multiple converging images, using automatic image to image registry methods and image correspondence algorithms, which allow a great degree of automatization and a greater ease of use, with a very low cost. This thesis tries to establish a DEM collection methodology of an experimental zone in a laboratory after repeated episodes of simulated rain by means of photogrammetric techniques based on SfM. Based on the obtained DEM, an estimation of the erosion using DEM of Difference (DoD) techniques will be carried out, comparing these estimations with the results of the obtained run-off and infiltration to validate the method. The results show the suitability of this technique for laboratory erosion studies.
[ES] La erosión hídrica del suelo es hoy un problema económico y ecológico en todo el mundo. La investigación actual de los procesos que intervienen en la erosión requiere información detallada sobre la topografía de la superficie del suelo con resolución y precisión adecuadas a la escala de trabajo. Una parte de los estudios que se realizan para la modelización y cuantificación de los procesos erosivos se llevan a cabo en laboratorio, a escalas de detalle (milimétricas), y necesitan métodos capaces de proporcionar mediciones precisas de la superficie, de una manera eficiente. Los experimentos realizados en laboratorio para la medición de la erosión hídrica se basan en el uso de simuladores de lluvia sobre parcelas de suelo de reducidas dimensiones. La rugosidad o microrrelieve del suelo influye considerablemente en el reparto de agua de lluvia entre infiltración y escorrentía, y es un parámetro importante para la modelización de procesos erosivos. La medición precisa del relieve de la parcela antes y después de la simulación de la lluvia permite estimar la erosión a partir de las diferencias de volumen. Así, en los últimos años se ha producido una creciente demanda de datos topográficos de precisión en el ámbito de las ciencias geomorfológicas. La representación de la superficie del suelo se realiza a través de Modelos Digitales de Elevaciones (MDE), generados a partir de datos altimétricos masivos, adquiridos mediante escáneres láser o por técnicas fotogramétricas basadas en imágenes. La obtención de estos datos se ha realizado mediante técnicas fotogramétricas clásicas (entre otras) hasta hace poco; sin embargo, no es una tarea trivial, y además para conseguir las precisiones necesarias se ha de trabajar con una metodología rigurosa que tenga en cuenta todas las fuentes de error en el proceso. Los avances experimentados en fotogrametría digital y otros ámbitos relacionados, como el procesamiento de imágenes y la visión por computador, han proporcionado nuevas herramientas software disponibles con gran potencial de aplicación en muchas y variadas disciplinas, entre ellas la geomorfología y el estudio de la erosión. El método Structure from Motion (SfM) obtiene de forma automática un modelo 3D de un objeto a partir de múltiples imágenes convergentes empleando métodos automáticos de registro imagen a imagen y algoritmos de correspondencia de imágenes, lo que permite un alto nivel de automatización y una mayor facilidad de uso, con un coste muy bajo. En esta tesis se pretende establecer una metodología para la obtención de MDE de una zona experimental en laboratorio tras sucesivos episodios de simulación de lluvia mediante técnicas fotogramétricas basadas en SfM. A partir de los MDE obtenidos se realizará una estimación de la erosión aplicando técnicas de diferencias de MDE (DoD), contrastando estas estimaciones con los resultados de los sedimentos arrastrados por la escorrentía y la infiltración para validar el método. Los resultados han demostrado la idoneidad de esta técnica en los estudios de erosión en laboratorio.
[CAT] L'erosió hídrica del sòl és actualment un problema econòmic i ecològic en tot el món. La investigació actual dels processos que intervenen en l'erosió requereix informació detallada sobre la topografia de la superfície del sòl amb resolució i precisió adequades a l'escala de treball. Una part dels estudis que es realitzen per a la modelització i quantificació dels processos erosius es duen a terme en laboratori, a escales de detall (mil·limètriques) , i necessiten mètodes capaços de proporcionar mesuraments precisos de la superfície, d'una manera eficient. Els experiments realitzats en laboratori per al mesurament de l'erosió hídrica es basen en l'ús de simuladors de pluja sobre parcel·les de sòl de reduïdes dimensions. La rugositat o microrrelleu del sòl influeix considerablement en el repartiment d'aigua de pluja entre infiltració i escolament, i és un paràmetre important per a la modelització de processos erosius. La medició precisa del relleu de la parcel·la abans i després de la simulació de la pluja permet estimar l'erosió a partir de les diferències de volum. Així, en els últims anys s'ha produït una creixent demanda de dades topogràfiques de precisió en l'àmbit de les ciències geomorfològiques. La representació de la superfície del sòl es realitza a través de Models Digitals d'Elevacions (MDE) , generats a partir de dades altimètriques massives, adquirides per mitjà d'escàners làser o per tècniques fotogramètriques basades en imatges. La obtenció d'estes dades s'ha realitzat amb tècniques fotogramètriques clàssiques (entre altres) fins fa poc; no obstant això, no és una tasca trivial, i a més per a aconseguir les precisions necessàries s'ha de treballar amb una metodologia rigorosa que tinga en compte totes les fonts d'error en el procés. Els avanços experimentats en fotogrametria digital i altres àmbits relacionats, com el processament d'imatges i la visió per computador, han proporcionat noves ferramentes disponibles amb gran potencial d'aplicació en moltes i variades disciplines, entre elles la geomorfologia i l'estudi de l'erosió. El mètode Structure from Motion (SfM) obté de forma automàtica un model 3D d'un objecte a partir de múltiples imatges convergents emprant mètodes automàtics de registre imatge a imatge i algoritmes de correspondència d'imatges, la qual cosa permet un alt nivell d'automatització i una major facilitat d'ús, amb un cost molt baix. En esta tesi es pretén establir una metodologia per a l'obtenció de MDE d'una zona experimental en laboratori després de successius episodis de simulació de pluja per mitjà de tècniques fotogramètriques basades en SfM. A partir dels MDE obtinguts es realitzarà una estimació de l'erosió aplicant tècniques de diferències de MDE (DoD) , contrastant estes estimacions amb els resultats dels sediments arrossegats per l'escolament i la infiltració per a validar el mètode. Els resultats han demostrat la idoneïtat d'esta tècnica en els estudis d'erosió en laboratori.
Balaguer Puig, M. (2015). Análisis empírico de soluciones fotogramétricas en estudios de erosión hídrica en laboratorio [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58989
TESIS

A esfera é utilizada como domínio computacional na modelagem de diversos fenômenos físicos, como em previsão numérica do tempo. Sua discretização pode ser feita de diversas formas, sendo comum o uso de malha regulares em latitude/longitude. Recentemente, também para melhor uso de computação paralela, há uma tendência ao uso de malhas mais isotrópicas, dentre as quais a icosaédrica. Apesar de já existirem modelos atmosféricos que usam malhas icosaédricas, não há consenso sobre as metodologias mais adequadas a esse tipo de malha. Nos propusemos, portanto, a estudar em detalhe diversos fatores envolvidos no desenvolvimento de modelos atmosféricos globais usando malhas geodésicas icosaédricas. A discretização usual por volumes finitos para divergente de um campo vetorial utiliza como base o Teorema da Divergência e a regra do ponto médio nas arestas das células computacionais. A distribuição do erro obtida com esse método apresenta uma forte relação com características geométricas da malha. Definimos o conceito geométrico de alinhamento de células computacionais e desenvolvemos uma teoria que serve de base para explicar interferências de malha na discretização usual do divergente. Destacamos os impactos de certas relações de alinhamento das células na ordem da discretização do método. A teoria desenvolvida se aplica a qualquer malha geodésica e também pode ser usada para os operadores rotacional e laplaciano. Investigamos diversos métodos de interpolação na esfera adequados a malhas icosaédricas, e abordamos o problema de interpolação e reconstrução vetorial na esfera em malhas deslocadas. Usamos métodos alternativos de reconstrução vetorial aos usados na literatura, em particular, desenvolvemos um método híbrido de baixo custo e boa precisão. Por fim, utilizamos as técnicas de discretização, interpolação e reconstrução vetorial analisadas em um método semi-lagrangiano para o transporte na esfera em malhas geodésicas icosaédricas. Realizamos experimentos computacionais de transporte, incluindo testes de deformações na distribuição do campo transportado, que mostraram a adequação da metodologia para uso em modelos atmosféricos globais. A plataforma computacional desenvolvida nesta tese, incluindo geração de malhas, interpolações, reconstruções vetoriais e um modelo de transporte, fornece uma base para o futuro desenvolvimento de um modelo atmosférico global em malhas icosaédricas.
Spherical domains are used to model many physical phenomena, as, for instance, global numerical weather prediction. The sphere can be discretized in several ways, as for example a regular latitude-longitude grid. Recently, also motivated by a better use of parallel computers, more isotropic grids have been adopted in atmospheric global circulation models. Among those, the icosahedral grids are promising. Which kind of discretization methods and interpolation schemes are the best to use on those grids are still a research subject. Discretization of the sphere may be done in many ways and, recently, to make better use of computational resources, researchers are adopting more isotropic grids, such as the icosahedral one. In this thesis, we investigate in detail the numerical methodology to be used in atmospheric models on icosahedral grids. The usual finite volume method of discretization of the divergence of a vector field is based on the divergence theorem and makes use of the midpoint rule for integration on the edges of computational cells. The error distribution obtained with this method usually presents a strong correlation with some characteristics of the icosahedral grid. We introduced the concept of cell alignment and developed a theory which explains the grid imprinting patterns observed with the usual divergence discretization. We show how grid alignment impacts in the order of the divergence discretization. The theory developed applies to any geodesic grid and can also be used for other operators such as curl and Laplacian. Several interpolation schemes suitable for icosahedral grids were analysed, including the vector interpolation and reconstruction problem on staggered grids. We considered alternative vector reconstruction methods, in particular, we developed a hybrid low cost and good precision method. Finally, employing the discretizations and interpolations previously analysed, we developed a semi-Lagrangian transport method for geodesic icosahedral grids. Several tests were carried out, including deformational test cases, which demonstrated that the methodology is suitable to use in global atmospheric models. The computational platform developed in this thesis, including mesh generation, interpolation, vector reconstruction and the transport model, provides a basis for future development of global atmospheric models on icosahedral grids.

La sismotectonique de deux zones de collision continentale en iran a ete etudiee. Dans le zagros central au sud de l'iran, nous utilisons des donnees microsismiques et geodesiques. A l'aide d'un reseau de 30 stations qui ont fonctionne en novembre et decembre 1997, 416 microseismes ont ete localises et 79 solutions focales calculees. La structure de la croute dans cette partie du zagros a ete determinee en utilisant la methode d'inversion 1-d et la methode de fonction de transfert. Il montre qu'une couche de sediments de 11 km est placee au dessus d'une croute d'epaisseur totale de 48 km. La microsismicite observee dans cette region est superficielle (8-16 km) et elle est situee dans le socle metamorphique precambrien sous l'epaisse couche de sediments. Cette sismicite montre plusieurs alignements paralleles aux axes des plis orientes nw-se avec un pendage fort vers le sw. L'analyse des mecanismes au foyer montre des mecanismes en coulissage (dextre sur un plan oriente nw-se) et des mecanismes en chevauchement. La deformation de cette region est aussi etudiee a partir de donnees geodesiques (gps) de deux campagnes successives en 1997 et 2000. Le resultat montre un raccourcissement d'environ 1 cm/an affectant la largeur totale du zagros suivant une direction n-ne, a peu pres parallele a la direction de mouvement de l'arabie par rapport a l'eurasie. Dans l'alborz, au nord de l'iran un reseau de 30 stations a fonctionne en juin et juillet 1998 dans la region de roudbar ou un seisme destructeur a eu lieu en 1990. La structure crustale a ete determinee par inversion 1-d et par la methode de fonction de transfert et montre une croute a 35 km d'epaisseur. La sismicite dans cette region est superficielle (4-16 km) et elle se situe plutot dans le socle cristallin. Elle montre un alignement oriente nw-se associe probablement aux failles chevauchantes de manjil et klishoum et aux failles coulissantes de kabateh et zardgoli. Des mecanismes au foyer indiquent des failles inverses et de coulissage.

This thesis is largely concerned with the changing representations of 'boundary' or 'ideal' points of a pseudo-Riemannian manifold -- and our primary interest is in the space-times of general relativity. In particular, we are interested in the following question: What assumptions about the 'nature' of 'portions' of a certain 'ideal boundary' construction (essentially the 'abstract boundary' of Scott and Szekeres (1994)) allow us to define precisely the topological type of these 'portions', i.e., to show that different representations of this ideal boundary, corresponding to different embeddings of the manifold into others, have corresponding 'portions' that are homeomorphic?

The aim of this thesis is to construct exact, axially symmetric solutions of Einstein- Maxwell(-dilaton) equations, which possess a discrete translational symmetry along an axis. We present two possible approaches to their construction. The first one is to solve Einstein-Maxwell equations, the second one relies on a dimensional reduction from a higher dimension. We examine the geometry of the solutions, their horizons and singu- larities, motions of charged test particles and compare them. 1

Aerospace structures comprising of metals and composites are exposed to extreme loading and environmental conditions which necessitates regular inspection and maintenance to verify and monitor overall structural integrity. The timely and accurate detection, characterization and monitoring of structural cracking, corrosion, delaminating, material degradation and other types of damage are of major concern in the operational environment. Along with these, stringent requirements of safety and operational reliability have lead to evolutionary methods for evaluation of structural integrity. As a result, conventional nondestructive evaluation methods have moved towards a new concept, Structural Health Monitoring (SHM). SHM provides in-situ information a bout the occurrence of damage if any, location and severity of damage and residual life of the structure and also helps in improving the safety, reliability and confidence levels of critical engineering structures. While the concepts underlying SHM are well understood, development of methods is still in a nascent stage which requires extensive research that is challenging and has been the main motivating factor for undertaking the work reported in the thesis. Under the scope of the investigations carried out in this thesis, an integrated approach using Ultrasonic (active) and Acoustic Emission (passive) methods has been explored for SHM of metallic and composite plate structures using a distributed array of surface bonded circular piezoelectric wafer active sensors(PWAS). In ultrasonic method, PWAS is used for actuation and reception of Lamb waves in plate structures. The damage detection is based on the interaction of waves with defects resulting in reflection, mode conversion and scattering. In acoustic emission (AE) technique, the same sensor is used to pick up the stress waves generated by initiation or growth of defects or damage. Thus, both the active and passive damage detection methods are used in this work for detection, location and characterization of defects and damage in metallic and composite plates with complex geometries and structural discontinuities. And, thus the strategy adopted is to use time-frequency analysis and time reversal technique to extract the information from Lamb wave signals for damage detection and a geodesic based Lamb wave approach for location of the damage in the structure. To start with experiments were conducted on aluminum plates to study the interaction of Lamb waves with cracks oriented at different angles and on a titanium turbine blade of complex geometry with a fine surface crack. Further, the interaction of Lamb wave modes with multiple layer delaminations in glass fiber epoxy composite laminates was studied. The data acquired from these experiments yielded complex sets of signals which were not easily discern able for obtaining the information required regarding the defects and damage. So, to obtain a basic understanding of the wave patterns, Spectral finite element method has been employed for simulation of wave propagation in composite beams with damages like delamination and material degradation. Following this, time-frequency analysis of a number of simulated and experimental signals due to elastic wave scattering from defects and damage were performed using wavelet transform (WT) and Hilbert-Huang transform(HHT).And, a comparison of their performances in the context of quantifying the damages has given detailed insight into the problem of identifying localized damages, dispersion of multi-frequency non-stationary signals after their interaction with different types of defects and damage, finally leading to quantification. Conventional Lamb wave based damage detection methods look for the presence of defects and damage in a structure by comparing the signal obtained with the baseline signal acquired under healthy conditions. The environmental conditions like change in temperature can alter the Lamb wave signals and when compared with baseline signals may lead to false damage prediction. So, in order to make Lamb wave based damage detection baseline free, in the present work, the time reversal technique has been utilized. And, experiments were conducted on metallic and composite plates to study the time reversal behavior ofA0 andS0Lamb wave modes. Damage in the form of a notch was introduced in an aluminum plate to study the changes in the characteristics of the time reversed Lamb wave modes experimentally. This experimental study showed that there is no change in the shape of the time reversed Lamb wave in the presence of defect implying no breakage of time reversibility. Time reversal experiments were further carried out on a carbon/epoxy composite T-pull specimen representing a typical structure. And, the specimen was subjected to a tensile loading in a Universal testing machine. PWAS sensor measurements were carried out at no load as also during different stages of delamination due to tensile loading. Application of time reversed A 0 and S0 modes for both healthy and delaminated specimens and studying the change in shape of the time reversed Lamb wave signals has resulted in successful detection of the presence of delamination. The aim of this study has been to show the effectiveness of Lamb wave time reversal technique for damage detection in health monitoring applications. The next step in SHM is to identify the damage location after the confirmation of presence of damage in the structure. Wave based acoustic damage detection methods (UT and AE) employing triangulation technique are not suitable for locating damage in a structure which has complicated geometry and contains structural discontinuities. And, the problem further gets compounded if the material of the structure is anisotropic warranting complex analytical velocity models. In this work, a novel geodesic approach using Lamb waves is proposed to locate the AE source/damage in plate like structures. The approach is based on the fact that the wave takes minimum energy path to travel from the source to any other point in the connected domain. The geodesics are computed numerically on the meshed surface of the structure using Dijkstra’s algorithm. By propagating the waves in reverse virtually from these sensors along the geodesic path and by locating the first inter section point of these waves, one can get the AE source/damage location. Experiments have been conducted on metallic and composite plate specimens of simple and complex geometry to validate this approach. And, the results obtained using this approach has demonstrated the advantages for a practicable source location solution with arbitrary surfaces containing finite discontinuities. The drawback of Dijkstra’s algorithm is that the geodesics are allowed to travel along the edges of the triangular mesh and not inside them. To overcome this limitation, the simpler Dijkstra’s algorithm has been replaced by a Fast Marching Method (FMM) which allows geodesic path to travel inside the triangular domain. The results obtained using FMM showed that one can accurately compute the geodesic path taken by the elastic waves in composite plates from the AE source/damage to the sensor array, thus obtaining a more accurate damage location. Finally, a new triangulation technique based on geodesic concept is proposed to locate damage in metallic and composite plates. The performances of triangulaton technique are then compared with the geodesic approach in terms of damage location results and their suitability to health monitoring applications is studied.

The aim of this dissertation is to give explicit descriptions of the set of proper holomorphic mappings between two complex manifolds with reasonable restrictions on the domain and target spaces. Without any restrictions, this problem is intractable even when posed for do-mains in . We give partial results for special classes of manifolds. We study, broadly, two types of structure results: Descriptive. The first result of this thesis is a structure theorem for finite proper holomorphic mappings between products of connected, hyperbolic open subsets of compact Riemann surfaces. A special case of our result follows from the techniques used in a classical result due to Remmert and Stein, adapted to the above setting. However, the presence of factors that have no boundary or boundaries that consist of a discrete set of points necessitates the use of techniques that are quite divergent from those used by Remmert and Stein. We make use of a finiteness theorem of Imayoshi to deal with these factors. Rigidity. A famous theorem of H. Alexander proves the non-existence of non-injective proper holomorphic self-maps of the unit ball in . ,n >1. Several extensions of this result for various classes of domains have been established since the appearance of Alexander’s result, and it is conjectured that the result is true for all bounded domains in . , n > 1, whose boundary is C2-smooth. This conjecture is still very far from being settled. Our first rigidity result establishes the non-existence of non-injective proper holomorphic self-maps of bounded, balanced pseudo convex domains of finite type (in the sense of D’Angelo) in ,n >1. This generalizes a result in 2, by Coupet, Pan and Sukhov, to higher dimensions. As in Coupet–Pan–Sukhov, the aforementioned domains need not have real-analytic boundaries. However, in higher dimensions, several aspects of their argument do not work. Instead, we exploit the circular symmetry and a recent result in complex dynamics by Opshtein. Our next rigidity result is for bounded symmetric domains. We prove that a proper holomorphic map between two non-planar bounded symmetric domains of the same dimension, one of them being irreducible, is a biholomorphism. Our methods allow us to give a single, all-encompassing argument that unifies the various special cases in which this result is known. Furthermore, our proof of this result does not rely on the fine structure (in the sense of Wolf et al.) of bounded symmetric domains. Thus, we are able to apply our techniques to more general classes of domains. We illustrate this by proving a rigidity result for certain convex balanced domains whose automorphism groups are assumed to only be non-compact. For bounded symmetric domains, our key tool is that of Jordan triple systems, which is used to describe the boundary geometry.

碩士
國立中央大學
應用地質研究所
93
Global Positioning System(GPS) is commonly used in geodetic survey. In this reason, we use GPS geodesy to study crustal deformation and fault`s displacement in Tungshiau、Yuanli、sanyi of MiaoLi and Dajia of TaiChung and to interpret the relationship of crustal deformation of the Tienchenshan anticline and subsurface Futoukeng fault. This study comprise two parts. First, we assemble the field survey GPS data from Central Geological Survey and NCU and continuously recording GPS stations. GPS data is proceeded using Bernese GPS software v.4.2 to obtain repeatable quantity of baseline and annual horizontal slip velocities. Secondly, we use Poly3D and Poly3dinv software to infer the subsurface structure. Poly3D assume that the mass is an elasticity body, which establishes one or more discontinuity planes composed by polygonal elements. We can made displacement by giving stress on these discontinuity planes, proceed to calculate the surface displacement. Then we apply Poly3Dinv to model the fault displacement using surface velocity. An interaction of Comparing modeled displacement with observed GPS data we can better constrain the subsurface geometry of the Futokeng fault.

碩士
國立成功大學
測量及空間資訊學系
105
Geodetic data between 2002 and 2015, composed of 65 campaign-mode GPS stations, 35 dual-frequency and 9 single-frequency continuous GPS stations and 10 leveling routes and PSInSAR, were collected in this study to understand the present-day kinematics of active structures in SW Taiwan. All velocities are relative to the station KMNM. The azimuths of horizontal velocities represent an apparent counterclockwise rotation from EW to WSW. Average horizontal velocity east of the Chishan fault is about 55.3 mm/yr, N260° - N270°. To the west, velocities gradually decrease westward to about 24.9 mm/yr, N250° - N260°. An obvious velocity gradient of 20 - 30 μstrain/yr is shown between the Chishan fault and the Longchuan - Hsiaokangshan faults. For the vertical velocity field, velocity west of the Hsiaokangshan fault is close to zero, while the velocity east of the Hsiaokangshan fault is approximately 10 - 20 mm/yr. An obvious uplift is shown between the Chishan fault and the Longchuan fault. The maximum uplift is about 80 - 90 mm/yr. The uplift rate west of Chishan fault is about 5 - 10 mm/yr, while the velocity east of Chishan fault is close to zero. For the PSInSAR result, an obvious deformation is toward southwest from the Longchuan fault to the east of the Youchang fault. The deformation in the west of Hsiaokangshan fault is less than other places. From the GPS velocities and PSInSAR sesult, an obvious velocity gradient is shown the Gunshuiping mud volcano toward the Tadishan mud volcano on both sides. Subsequent analysis named this faulted fault as the Tadishan fault. And the Longchuan fault may be extended westward to connect with the Youchang fault. The Hsiaokangshan fault and the Gutingkeng fault extend southwestward. From the analysis, the mud diapirs cause the footwall of Chishan fault upliftingand acting as normal faulting near the Chuongliao Tunnel and Tianliao Viaduct. Finally, through the velocity and strain rate analysis, in this study area we proposed that the surface deformation in SW Taiwan is affected by the interaction between the kinematics of the faults and the upward motion of the mud diapirs.

碩士
國立臺灣大學
地質科學研究所
100
Earthquake magnitude and coseismic deformation are strongly related to the geometry of the seismogenic fault. Consequently, the construction of a comprehensive 3-D fault geometry model for the linkage and interaction of fault systems becomes one of the essential topics in neotectonic studies. The Western Foothills of Taiwan is undergoing an active deformation of the Taiwan orogeny demonstrated by the frequent seismicity and destructive earthquake events. The study region includes several faults-and-folds systems from Hsinchu and Hsincheng faults in the north to Okungchi and Hoping faults in the south in the internal and external western Foothills in Hsinchu area. The structures in Hsinchu area show wide and gentle folds associated with NNW-SSW trending thrust faults in internal Foothills and tide and steep folds associated with the E-W trending thrust faults in external Foothills. From the seimostectonic viewpoint, the earthquakes frequently occur in internal Foothills than external Foothills. Therefore, the main purpose of this study is to investigate the linkage of subsurface structures between internal and external western Foothills in Hsinchu area. To this purpose, we restore a cross-section across Hsinchu and Hsincheng faults, and clarify the overall structural evolution of major fault systems based on this restoration. By integrating eleven CPC geological cross-sections and the profile in this study, we use GeoSec 3D software to construct 3D fault geometry model beneath Hsinchu area. Finally, we use GOCAD software to integrate 3D relocated seismicity and 3D fault model in order to explore the relationships between active structures and seismicities. In terms of the profile reconstruction, the thickness of strata gradually increasing eastward was induced by abundant normal faults activating in early Miocene. However, Talu shale pinched out instead. According to restoration of balanced cross section, the Juanchiao fault, Chutung fault and Peipu fault are in-sequence fault systems, meanwhile the Hsinchu and Hsincheng faults are out-of-sequence fault systems. The Chingtsaohu anticline formed following the Peipu fault. After that, Hsinchu fault cut through the Chingtsaohu anticline and Hsincheng fault, bedding fault, formed in the end. The displacements along the Hsinchu and Hsincheng fauts are 1318 m and 887 m, respectively. We assumed the faults formed after the deposition of Cholan formation, therefore, the long term slip rates for Hsinchu and Hsincheng faults are 0.43 mm/yr and 0.37 mm/yr respectively. Also, short term slip rate of Hsincheng fault is larger than 0.37 mm/yr. As a result, it implies Hsincheng fault is possible a recently active structure in Hsinchu area. The average strain rate across Hsincheng fault is -0.05 μ strain/yr, and the coseismic strain drop divided by strain rate gets 600-6000 years. Therefore, we suggest the recurrence interval of Hsincheng fault is 600-6000 years. Base on the analysis of seismicity and geological profiles, the numbers of earthquakes are larger in internal than external foothills. Clusters at the bend of Juanchiao fault at depth imply that it is the location of stress generating. According to 3D seismicity and fault model, earthquake events occur northward in 1999, 2007, 2003, 2006. The 3D fault model indicates faults at depth become gentler in internal foothills, while faults in external foothills turn into steeper. The boundary fault, Juanchiao fault, shows subsurface high angle thrust and stepped fault geometry at depth. Furthermore, the detachment becomes deeper eastward, from 6-7 km to 10 km.

This thesis attempts to resolve the contradictory relationship between the ecological merits of wood construction and the significant material intensity of recent free form timber surface structures. The building industry is now adept in the design and construction of freeform surface architecture, however new challenges have been introduced with the environmentally conscious desire to build these structures in wood. Lacking the formal versatility of steel and concrete, wood introduces a great deal of difficulty in the realization of complex form at an architectural scale. Powerful digital design and fabrication tools have recently made it possible to model, analyze and construct these buildings, but at the cost of heavy structural solutions that involve energy intensive fabrication processes and significant material waste. This approach contradicts the ecological benefits of wood, and raises the question of whether it is possible to achieve free and expressive form in timber surface architecture while maintaining an economy of means and material. This question is addressed through the development of a generative design tool for the creation of material conscious free form timber surface architecture. The formation of the tool is informed by the field of computational morphogenesis, which draws from the natural growth processes of biological structures in the virtual synthesis of form. The tool is conceived as a morphogenetic material system, which consists of a generative algorithm that integrates material, structure and form in a single computational process. Specific material saving techniques deployed in the algorithm draw from existing research in timber shell design and material optimization. Established methods in the use of geodesic lines for the structural patterning of wood shells and stress driven material distribution make up the core concepts deployed in the algorithm. The material system is developed, refined and tested through the design and construction of an experimental free form timber lattice.

Στην παρούσα διατριβή διερευνήθηκε η δυνατότητα του GPS-RTS στη μελέτη ταλαντώσεων ως προς την ακρίβεια προσδιορισμού του εύρους και της συχνότητας ταλάντωσης και το διάστημα των συχνοτήτων που μπορούν να καταγραφούν, με βάση συσκευή παραγωγής ελεγχόμενων εξαναγκασμένων ταλαντώσεων και ακολουθήθηκε στατιστική ανάλυση δεδομένων. Τα πειράματα βασίστηκαν στην σύγκριση των καταγραφών ταλαντώσεων γνωστών χαρακτηριστικών που δημιούργησε η συσκευή και την σύγχρονη καταγραφή τους με τα όργανα GPS και RTS και εν μέρη άμεση οπτική παρατήρηση. Κατά την φάση των πειραμάτων αντιμετωπίστηκαν προβλήματα απώλειας των μετρήσεων τα οποία εκτιμάται ότι μπορούν να αντιμετωπιστούν με κατάλληλη συνδεσμολογία για το GPS και κατάλληλο λογισμικό για το RTS Οι χρονοσειρές που προέκυψαν από περισσότερα από 100 πειράματα αναλύθηκαν με συμβατικές στατιστικές μεθόδους (π.χ. έλεγχο χονδροειδών σφαλμάτων) και φασματική ανάλυση με βάση τις μεθόδους: FFT, το περιοδόγραμμα Lomb και την Φασματική Ανάλυση Ελαχίστων Τετραγώνων (LSSA). Με βάση τις προτεινόμενες μεθόδους αναλύσεων προέκυψαν τα παρακάτω: • το GPS μπορεί να καταγράψει με ακρίβεια ταλαντώσεις με συνολικό εύρος ≥4cm για συχνότητες διέγερσης ≤4 Hz ενώ μπορεί να προσδιορίσει την συχνότητα ταλάντωσης ακόμα για διέγερση των 4 Hz και • το RTS μπορεί να καταγράψει με ακρίβεια ταλάντωσης με συνολικό εύρος ταλάντωσης της τάξης του 1 cm και μπορεί να προσδιορίσει με ακρίβεια την συχνότητα διέγερσης για χαμηλόσυχνές ταλαντώσεις (μέχρι και 1 Hz). Συμπερασματικά, οι μέθοδοι επίγειων αλλά και δορυφορικών μεθόδων μπορούν να χρησιμοποιηθούν για την παρακολούθηση των ταλαντώσεων/μετακινήσεων των εύκαμπτων κατασκευών, ενώ με βελτίωση των διατάξεών τους και των λογισμικών τους με στόχο να αντιμετωπιστούν τα προβλήματα που παρουσιάστηκαν, αναμένεται ακόμα καλύτερη ακρίβεια.
At the present study, the ability of GPS-RTS was examined for the oscillation monitoring.At the present thesis, the performance of the modern geodetic methods, GPS and RTS, for the oscillation monitoring was examined. In order to assess the performance of the two methods the study was based on known oscillations which were produced by a special oscillation device and the records of GPS and RTS which were monitoring the oscillations. The estimate of the performance was based on the comparison of the known oscillation characteristics (displacement and frequency) and those which were arose by the analysis of the GPS-RTS records. During the oscillation experiments many problems were faced and especially with interruptions at the GPS and RTS records, which can be solved by a more appropriate connection between the antenna and the receiver of the GPS system and the use of a more advanced software for the RTS. Time series, based on the GPS-RTS records of more than 100 oscillations experiments, were analysed with compatible statistical and frequency domain analysis methods: FFT, LSSA (Least Square Spectrum Analysis) and Lomb. According to the analysis: • GPS can define accurately the total oscillation displacement when it is ≥4cm and the frequency when it is ≤4 Hz and • RTS can define accurately the total oscillation displacement when it is ≥1cm and the frequency when it is ≤1 Hz. According to the analysis, the two geodetic methods proved to be very accurate for the oscillation monitoring of flexible structures and their performance can be improved with the use of more sophisticated software for the RTS and connections for the GPS.

abstract: I investigate the Black Canyon City landslide (BCC landslide), a prominent deep-seated landslide located northeast of Black Canyon City, Arizona. Although the landslide does not appear to pose a significant hazard to structures, its prominent features and high topographic relief make it an excellent site to study the geologic setting under which such features develop. This study has the potential to contribute toward understanding the landscape evolution in similar geologic and topographic settings, and for characterizing the underlying structural processes of this deep-seated feature. We use field and remotely-based surface geology and geomorphological mapping to characterize the landslide geometry and its surface displacement. We use the Structure from Motion (SfM) method to generate a 0.2 m resolution digital elevation model and rectified ortho-photo imagery from unmanned aerial vehicle (UAV) - and balloon-based images and used them as the base map for our mapping. The ~0.6 km2 landslide is easily identified through remotely-sensed imagery and in the field because of the prominent east-west trending fractures defining its upper extensional portion. The landslide displaces a series of Early and Middle Miocene volcanic and sedimentary rocks. The main head scarp is ~600 m long and oriented E-W with some NW-SE oriented minor scarps. Numerous fractures varying from millimeters to meters in opening were identified throughout the landslide body (mostly with longitudinal orientation). The occurrence of a distinctive layer of dark reddish basalt presents a key displaced marker to estimate the long-term deformation of the slide mass. Using this marker, the total vertical displacement is estimated to be ~70 m, with maximum movement of ~95 m to the SE. This study indicates that the landslide motion is translational with a slight rotational character. We estimate the rate of the slide motion by resurvey of monuments on and off the slide, and examination of disturbed vegetation located along the fractures. The analysis indicates a slow integrated average landslide velocity of 10-60 mm/yr. The slide motion is probably driven during annual wet periods when increased saturation of the slide mass weakens the basal slip surface and the overall mass of the slide is increased. Results from our study suggest that the slide is stable and does not pose significant hazard for the surrounding area given no extreme changes in the environmental condition. Although the landslide is categorized as very slow (according to Cruden and Varnes, 1996), monitoring the landslide is still necessary.
Dissertation/Thesis
Masters Thesis Geological Sciences 2016

The subject of study of this thesis is the Kerr-Newman-(anti-)de Sitter space- time, a rotating and charged exact black-hole solution of the Einstein-Maxwell equations with a non-zero cosmological constant. In the first part of the thesis we examine admissible extremal configurations, present the corresponding Penrose diagrams, and investigate the effects of frame-dragging. In the second part, we follow the motion of charged particles via the Lagrangian formalism, focusing on the equatorial plane and the axis where we arrived at some analytic results con- cerning the trajectories. Static particles, effective potentials and - in the case of the equatorial plane - stationary circular orbits are examined. We also perform numerical simulations of particle motion to be able to check our analytic results and also to foster our intuition regarding the behaviour of the test particles. The last part concerns quantum tunnelling of particles through the space-time's hori- zons, specifically the null geodesic method. The main goal of these computations is to obtain horizon temperatures, in which we succeed up to a constant multi- plicative factor. We discuss various pitfalls of the method and stake out a possible approach when applying it to the extreme horizons present in KN(a)dS. 1