Dissertations / Theses on the topic 'Displacement patterns'

The commercial exploitation of Electronic Speckle Pattern Interferometry (ESPI) is now gathering pace with manufacturers marketing products in Europe and the USA. The power of the technique both in a research and an industrial inspection role has brought pressure from the engineering community for an automated fringe analysis system.

Contemporary population displacement trends are impacting cities located in developing countries in unprecedented ways. This scenario is reflected in the Mexican border town of Tijuana, which from May 2016 to January of 2017, experienced the massive arrival of Haitians seeking asylum in the United States. My thesis addresses the Haitians’ patterns of displacement and the actors involved in their migratory processes including governmental and non-governmental authorities in Mexico and the United States. Because of the complexity of displacement today, I argue that in order to comprehend patterns and responses to displacement, it is necessary to use a multi-scalar global perspective that addresses the relationship between time and space as well as the relationship between politics and power. Furthermore, I argue that the Haitians' arrival to the U.S.-Mexico border is an illustration of crisis migration, which views displacement as the result of a combination of social, political, economic, and environmental crises.

After the excavation of a cut slope ongoing deformations on the slope surface can often be measured. These deformations can be induced due to various processes and can also be used as an indicator of slope stability. If the reasons for the deformations are known, selective stabilization methods can help to decelerate, or stop, the movements. The potential for the recognition of displacement patterns in excavated slopes is studied in this dissertation. In the laboratory, the analysis of displacement patterns due to various processes is difficult as identical initial test conditions can hardly be reproduced. Furthermore, measurements of displacements can only be conducted to a limited degree. Therefore, numerical calculations using the finite element method were applied to simulate excavation processes and analyse the displacements. In addition, a suitable mathematical model has to be used to represent the stress-strain behaviour during the unloading process. Three different advanced constitutive soil models were chosen to calculate an excavation process of an idealized slope assuming drained conditions: - elasto-plastic Modified-Cam-Clay model - rate-independent hypoplastic model according to Masin - rate-dependent visco-hypoplastic model according to Niemunis Before conducting the excavation simulation, the soil parameters of the constitutive models were calibrated by means of numerical element tests, depicting the stress paths of conventional laboratory tests. Within the literature, those conventional laboratory tests are recommended for the determination of parameters for the constitutive models. A parameter set for the visco-hypoplastic model was chosen from literature. The parameters were adapted for the remaining models. Thus, all three models predicted approximately the same stress-strain behaviour during conventional laboratory tests. Despite the correlations during the element tests, the constitutive models predicted different displacements during the calculation of the excavation of an idealized slope under drained conditions. Thereupon, load-controlled triaxial compression tests were conducted reproducing the characteristic stress paths during an excavation process. At the same time, numerical calculations were carried out to reproduce the triaxial compression tests, and the measured and calculated displacement behaviour was compared. Different processes such as pure unloading due to excavation, excavation in overconsolidated soil, excavation coupled with consolidation, excavation coupled with previous ground water lowering and consolidation as well as the influence of creep effects were considered in the analysis of the displacement patterns during an excavation. It can be stated that the evaluation of displacements and changes in displacements in a single point on the slope surface cannot provide sufficient information about a certain physical process. Only the combination of displacement paths at different survey points will lead to a reliable conclusion. Thus, representative displacement patterns for different processes are recognizable during and after the excavation, which can be used for the identification. During the numerical simulation of an in-situ model test, where a slope was brought to failure by excavation, the calculated displacements were analysed for identifiable displacement patterns. It can be stated that despite different slope systems, consistencies were found within characteristic survey points. These points can be used to identify patterns within the displacement contours.

Master of Science<br>Department of Civil Engineering<br>Asad Esmaeily<br>Performance-based building design is a necessity in geographic locations where buildings are susceptible to large earthquakes and high winds. This design method requires an analysis of the performance of the structural system with loadings and deflections caused by earthquakes and wind. Current design codes include the load intensity in analysis procedures, but do not consider the effect of load pattern in the performance analysis of reinforced concrete columns. Because a thorough analysis must take into consideration load pattern and load intensity, computer software is ideal to analyze these systems. A computer program was originally developed by Esmaeily (USC_RC), and was revised later to be renamed (KSU_RC) in order to make the analysis of concrete column performance accurate, yet simple for design purposes. This analytical tool used analytical methods and material models, verified against experimental data, to accurately predict the performance of reinforced concrete columns under various loading conditions, including any pattern in lateral direction and independently variable axial load. However, the program was limited to circular, rectangular, hollow circular and rectangular sections and uniaxial lateral curvature and displacement. The next generation of the program, KSU RC 2.0, was developed to overcome the aforesaid limitations.

This thesis is concerned with modeling geometric patterns. Specifically, a clear and practical definition for regular patterns is proposed. Based on this definition, this thesis proposes the following modeling setting to describe the semantic transfer of a model between various forms of pattern regularity: (1) recognition or identification of patterns in digital models of 3D assemblies and scenes, (2) pattern regularization, (3) pattern modification and editing by varying the repetition parameters, and (4) establishing exceptions (designed irregularities) in regular patterns. In line with this setting, this thesis describes a representation and approach for designing and editing hierarchical assemblies based on grouped, nested, and recursively nested patterns. Based on this representation, this thesis presents the OCTOR approach for specifying, recording, and producing exceptions in regular patterns. To support editing of free-form shape patterns on surfaces, this thesis also presents the imprint-mapping approach which can be used to identify, extract, process, and apply relief features on surfaces. Pattern regularization, modification, and exceptions are addressed for the case of relief features on surfaces.

This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.<br>Bachelors<br>Arts and Sciences<br>English Literature

Made available in DSpace on 2016-12-08T16:24:20Z (GMT). No. of bitstreams: 1 PGCA14MA150.pdf: 671118 bytes, checksum: 044e392b9e087c5b498a3cdbdfdf9d62 (MD5) Previous issue date: 2014-09-19<br>The sustainable management of pastures is in evidence in academic circles, looking for a better association between animal performance and natural resources conservation. The aim of this work was to evaluate cattle pattern displament on kikuiu-grass submitted to different heights and the same level of defoliation of 50%. The experiment was carried out at CAV/UDESC during April and May 2013. The experimental design was a complete randomized block design with three replications and four treatments. The treatments were four pre-grazing heights: 25, 20, 15 and 10 centimeters associated which were associated with a level of defoliation of 50%. Animals stand longer on feeding stations in 20 and 25 cm swards during the initial stage of grazing without differences on the final phase of grazings down. At the early stage, on the lower pasture height (10 cm) the animals walked more and moved more quickly when compared to those managed at higher swards heights (5,25 e 4,0, respectively). There was no difference during the final stage of grazings process. The bite number in each feeding station had a linear reduction with the increase in sward height during the initial phase, being minor on the 25 cm height (27 bites.feeding station-1), with no differences at the final stage. Bite rate (bites. min-1) also presented a linear response by reducing according the increase in pasture height, from 42,02 to 35,18 bites.min-1 in pastures with 10 and 25 cm, respectively. During the initial phase of the grazing down the animals presented diferences in displacement patterns, suggesting that swards heights of 20 to 25 cm (in kikuygrass) present better conditions to foraging search. At the final phase, the animals did not present differences among treatments, suggesting that on using 50% of the grazing down is already over the limit when the objective is to minimize forage searching<br>O manejo sustentável das pastagens está ganhando cada vez mais espaço na pesquisa mundial, visando maior desempenho animal aliado à preservação dos recursos naturais. O objetivo deste trabalho foi avaliar os padrões de deslocamento de bovinos em pastos de capim-quicuio, submetidos a diferentes alturas de entrada e mesma severidade de desfolhação de 50%. O experimento foi realizado no setor de bovinocultura leiteira do CAV/UDESC, durante os meses de abril e maio de 2013. O delineamento experimental foi em blocos completos casualizados com três repetições e quatro tratamentos. Os tratamentos eram quatro alturas em pré-pastejo: 25, 20, 15 e 10 cm, associados com uma severidade de desfolhação de 50% destas alturas. O maior tempo de permanência dos animais nas estações alimentares foi encontrado nos pastos mais altos, com 20 e 25 cm de altura, na fase inicial de rebaixamento dos pastos, sem diferenças na fase final do rebaixamento. Os animais caminharam mais (P.min-1) e com maior rapidez (passos entre estações) nos pastos mais baixos (10 cm), durante a fase inicial de rebaixamento destes. Já na fase final não foram observadas alterações. O número de bocados em cada estação alimentar na fase inicial do rebaixamento apresentou uma redução linear com o aumento da altura, sendo menor na altura de 25 cm (27,02), permanecendo sem diferenças na fase final. A taxa de bocados (bocados. min-1) também apresentou uma resposta linear, reduzindo conforme o aumento na altura dos pastos, de 42,02 para 35,18 bocados.min-1, nos pastos com 10 e 25cm, respectivamente. Os animais na fase inicial de rebaixamento dos pastos apresentaram diferenças nos padrões de deslocamento, indicando que alturas de dossel de 20 e 25 cm (em pastos de capim-quicuiu) apresentam melhores condições ao processo de forrageamento. Já na fase final, os animais não apresentaram diferenças entre os tratamentos, sugerindo que utilizando a faixa de 50% de rebaixamento dos pastos os animais já encontram dificuldades no processo de busca por forragem, independente de metas de alturas em pré-pastejo

Although the study of the interaction of acoustic and elastic waves with periodic surfaces and structures has a rich history dating back to Lord Rayleigh, it has recently been attracting new research efforts due to its value in the study of phononic crystals and in methods for ultrasonic non-destructive evaluation (NDE). The objective of the research described in this thesis is to provide new numerical and experimental tools capable of capturing important features that occur due to the diffraction of ultrasound on periodic solid surfaces. This thesis is divided into four main parts. First, the Rayleigh-Fourier (R-F) method will be used to simulate diffracted fields generated by structures containing multiple periodic surfaces and/or multiple solid layers. The second part of this thesis examines diffraction effects and compares ultrasonic NDE techniques for surfaces with imperfect periodicities. The third portion of this thesis focuses on one unusual phenomenon that has been observed on periodic surfaces, namely the lateral backward displacement of a bounded ultrasonic beam along the surface. This effect is currently understood to occur due to backward propagating surface waves that result from diffraction and mode conversion on the surface. The fourth and final part of this thesis describes the diffraction of bulk ultrasonic waves that can occur on the surfaces of phononic crystals.

This thesis deals with techniques for the displacement measurement of fast transient phenomena using ESPI. Four main contributions are presented. First, a computer model for speckle noise and ESPI fringe generation is proposed. An assessment methodology for speckle noise reduction algorithms is then derived using the computer model. Then the noise in the ESPI fringe patterns is analysed using computer generated speckle and several solutions for its reduction are proposed and assessed. Finally, a fast electro-optical system is presented as a solution to the unambiguous phase extraction problem from a single interferogram. With this novel system, whole field transient displacements occurring in time intervals as short as 20ns can be successfully registered and retrieved.

The term Gossamer is used to describe ultra-lightweight spacecraft structures that solve the aerospace challenge of obtaining maximum performance while reducing the launch costs of the spacecraft. Gossamer structures are extremely compliant, which complicates control design and ground testing in full scale. One approach is to design and construct smaller test articles and verify their computational models experimentally, so that similar computational models can be used to predict the dynamic performance of full-scale structures. Though measurement of both in-plane and out-of-plane displacements is required to characterize the dynamic response of the surface of these structures, this thesis lays the groundwork for dynamic measurement of the in-plane component. The measurement of thin films must be performed using non-contacting sensors because any contacting sensor would change the dynamics of the structure. Moreover, the thin films dealt with in this work are coated with either gold or aluminum for special applications making the film optically smooth and therefore requiring a surface pattern. A Krypton Fluoride excimer laser system was selected to fabricate patterns on thin-film mirror test articles. Parameters required for pattern fabrication were investigated. Effects of the pattern on the thin-film dynamics were studied using finite element analysis. Photogrammetry was used to study the static in-plane displacement of the thin-film mirror. This was performed to determine the feasibility of the photogrammetric approach for future dynamic tests. It was concluded that photogrammetry could be used efficiently to quantify dynamic in-plane displacement with high-resolution cameras and sub-pixel target marking.

Que ce soit dans le domaine médical ou en contrôle non destructif, les systèmes d’imagerie ultrasonore sont devenus de plus en plus utilisés de nos jours. Leurs applications ne cessent de s’élargir et des performances toujours plus accrues sont vivement recherchées, afin d’améliorer la qualité des diagnostics réalisés. Nous sommes donc passés de l’utilisation de systèmes à base de transducteurs ultrasonores mono-élément à des systèmes utilisant des réseaux de transducteurs à une dimension (1D) et à deux dimensions (2D) composés d’éléments de plus en plus nombreux et petits. Néanmoins, un phénomène indésirable est fortement présent dans ces réseaux de transducteurs ultrasonores : il s’agit du couplage inter-éléments tendant à limiter leurs performances acoustiques et à modifier leur diagramme de rayonnement. Tout au long de ce travail de recherche, nous avons donc cherché à comprendre ce phénomène parasite et à apporter des solutions pour le réduire voire le supprimer. En se basant sur des modélisations éléments finis 2D et 3D et grâce à la fabrication de prototypes, nous avons d’une part, mis en évidence les différents types de couplages présents dans un réseau de transducteurs (acoustique, mécanique) et d’autre part, deux méthodes de correction basées l’une comme l’autre sur l’application de tensions convenables aux différents éléments du réseau ont été testées. La première méthode utilise les déplacements normaux moyens à la surface de chaque élément du réseau pour évaluer ces tensions, tandis que la deuxième fait appel aux courants motionnels parcourant chaque élément pour les déterminer. Les résultats numériques et expérimentaux concernant les déplacements et les diagrammes de rayonnement sont en bon accord. En outre, les deux méthodes s’avèrent particulièrement efficaces pour réduire le couplage inter-éléments<br>Whether in medicine or in non-destructive testing, ultrasonic imaging systems have become increasingly used nowadays. Their applications continue to expand and good performances are needed to improve the quality of the diagnosis. Moreover, significant progress has been made since these systems were originally based on single element ultrasonic transducers and are now made of mono-dimensional (1D) and bi-dimensional (2D) elements arrays ever more numerous and smaller. However, an undesirable phenomenon is strongly present in the ultrasonic transducer arrays: it is the cross-talk, which limits their acoustic performances and modifies their radiation pattern. Throughout this research, we have attempted on one hand to understand this parasitic phenomenon and on the other hand to provide solutions in order to reduce it or even remove it. To highlight the cross-talk types (acoustic and mechanical) and to test the proposed correction methods, we developed two-dimensional (2D) and three-dimensional (3D) finite element modeling and fabricated some prototypes. Both correction methods rely on the application of suitable voltages to the array elements. The first method uses the average of the normal displacements at the surface of each element to evaluate the voltages, while the second one utilizes the motional currents through each element to determine them. The numerical and experimental results concerning the displacements and the radiation patterns are in good agreement. In addition to this, both methods have been efficiently performed to reduce the cross-talk

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-10-09T21:26:09Z No. of bitstreams: 2 Dissertação - Cristiano Martins da Silva - 2014.pdf: 7341655 bytes, checksum: 226de0d12135f6c83ee0123d4665ca11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)<br>Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-10-09T21:27:26Z (GMT) No. of bitstreams: 2 Dissertação - Cristiano Martins da Silva - 2014.pdf: 7341655 bytes, checksum: 226de0d12135f6c83ee0123d4665ca11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)<br>Made available in DSpace on 2015-10-09T21:27:26Z (GMT). No. of bitstreams: 2 Dissertação - Cristiano Martins da Silva - 2014.pdf: 7341655 bytes, checksum: 226de0d12135f6c83ee0123d4665ca11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-10-03<br>The development of the Brazilian urban networks followed the social and economical development of the regions, which at the same time resulted in a differential pattern in the articulation of the same networks, verifying the functional specificities of the urban centers, the polarizing role of the same and the degree of internal and external articulation of each network. In the same way, the regional inequalities reflect in the inequalities of access to health services. In this way, to understand the possibilities of the access of the population of the state of Goiás to public health equipment becomes important disposing about the spatial distribution of the same, because as said by Levy (2002) mobility becomes an important social capital, thus as Villaça (1998) classifies the location in the same way. The spatialization of the health public equipments comes to reflect these differences, as far from the point of view of the resources destined to the municipalities, as the spatial organization of the structures. In this sense, the reflection proposed in this work is to understand the factors of dispersion and the concentration of health and service equipments in the state of Goiás. Especially, to examine about this offering and demand resulting from the aglutination in the core municipalities. For both, it is intended to analyze the behavior of the displacements originated from the hospitalization during the year of the research comparatively to the patient’s local residence and the municipality of hospitalization, intending to identify the flow used by the users of SUS (Unified Health System known as Sistema Único de Saúde). Furthermore, to identify and to analyse a pattern of mobility of the patients in search of hospital and ambulatory treatment. Simultaneously, as support of our analysis, we aim to identify the conditioning factors of the access to health services, as characterizing the users of SUS, having the mobility as fundamental dimension for the existence of a more fair access and equitative of the health services. By the established considerations along this master thesis, it was recognized an excessive concentration of health services offering specialized in few municipalities, with great highlight for Goiânia. This expressive concentration alerts for the risk that the resident population in vast areas of the state needy of these services have major difficulties of access to more complex procedures in the necessary cases.<br>O desenvolvimento das redes urbanas brasileiras acompanhou o desenvolvimento socioeconômico das regiões, o que concomitantemente resultou em um padrão diferencial na articulação das mesmas, verificando as especificidades funcionais dos centros urbanos, o papel polarizador dos mesmos e o grau de articulação interna e externa de cada rede. De maneira homóloga, as desigualdades regionais se refletem nas desigualdades de acesso aos serviços de saúde na rede SUS. Desta forma, para compreender as possibilidades de acesso da população de Goiás aos equipamentos de saúde pública, torna-se importante dispor da distribuição espacial dos mesmos, pois como já afirmou Levy (2002) à mobilidade torna-se um importante capital social, assim como Villaça (1998) classifica a localização da mesma forma. A espacialização dos equipamentos de saúde pública vem a refletir tais disparidades, tanto do ponto de vista dos recursos destinados aos municípios, como da organização espacial das estruturas. Nesse sentido, a reflexão proposta neste trabalho é compreender os fatores da dispersão e a concentração dos equipamentos e serviço de saúde no estado de Goiás. Sobretudo, examinar a respeito dessa oferta e demanda resultantes da aglutinação nos municípios polos. Para tanto, pretende-se analisar o comportamento dos deslocamentos originados pelas internações hospitalares no decorrer do ano da pesquisa comparativamente ao local de residência do paciente e o município de internação, visando identificar o fluxo utilizado pelos usuários do SUS. Ademais, identificar e traçar um padrão de mobilidade dos pacientes em busca de atendimento hospitalar e ambulatorial. Simultaneamente, como suporte desta análise, identificar os fatores condicionantes do acesso aos serviços de saúde, bem como caracterizar os usuários do SUS, tendo a mobilidade como dimensão fundamental para a existência de um acesso mais justo e equitativo dos serviços de saúde. A partir das considerações estabelecidas ao longo desta dissertação, reconheceu-se que uma excessiva concentração da oferta de serviços de saúde especializados em poucos municípios, com grande destaque para Goiânia. Essa expressiva concentração alerta para o risco de que a população residente em vastas áreas do estado desprovidas desses serviços tenha maiores dificuldades de acesso a procedimentos mais complexos nos casos necessários.

Ce travail de thèse traite de la découverte de connaissances à partir de Séries Temporelles de Champs de Déplacements (STCD) obtenues par imagerie satellitaire. De telles séries occupent aujourd'hui une place centrale dans l'étude et la surveillance de phénomènes naturels tels que les tremblements de terre, les éruptions volcaniques ou bien encore le déplacement des glaciers. En effet, ces séries sont riches d'informations à la fois spatiales et temporelles et peuvent aujourd'hui être produites régulièrement à moindre coût grâce à des programmes spatiaux tels que le programme européen Copernicus et ses satellites phares Sentinel. Nos propositions s'appuient sur l'extraction de motifs Séquentiels Fréquents Groupés (SFG). Ces motifs, à l'origine définis pour l'extraction de connaissances à partir des Séries Temporelles d’Images Satellitaires (STIS), ont montré leur potentiel dans de premiers travaux visant à dépouiller une STCD. Néanmoins, ils ne permettent pas d'utiliser les indices de confiance intrinsèques aux STCD et la méthode de swap randomisation employée pour sélectionner les motifs les plus prometteurs ne tient pas compte de leurs complémentarités spatiotemporelles, chaque motif étant évalué individuellement. Notre contribution est ainsi double. Une première proposition vise tout d'abord à associer une mesure de fiabilité à chaque motif en utilisant les indices de confiance. Cette mesure permet de sélectionner les motifs portés par des données qui sont en moyenne suffisamment fiables. Nous proposons un algorithme correspondant pour réaliser les extractions sous contrainte de fiabilité. Celui-ci s'appuie notamment sur une recherche efficace des occurrences les plus fiables par programmation dynamique et sur un élagage de l'espace de recherche grâce à une stratégie de push partiel, ce qui permet de considérer des STCD conséquentes. Cette nouvelle méthode a été implémentée sur la base du prototype existant SITS-P2miner, développé au sein du LISTIC et du LIRIS pour extraire et classer des motifs SFG. Une deuxième contribution visant à sélectionner les motifs les plus prometteurs est également présentée. Celle-ci, basée sur un critère informationnel, permet de prendre en compte à la fois les indices de confiance et la façon dont les motifs se complètent spatialement et temporellement. Pour ce faire, les indices de confiance sont interprétés comme des probabilités, et les STCD comme des bases de données probabilistes dont les distributions ne sont que partielles. Le gain informationnel associé à un motif est alors défini en fonction de la capacité de ses occurrences à compléter/affiner les distributions caractérisant les données. Sur cette base, une heuristique est proposée afin de sélectionner des motifs informatifs et complémentaires. Cette méthode permet de fournir un ensemble de motifs faiblement redondants et donc plus faciles à interpréter que ceux fournis par swap randomisation. Elle a été implémentée au sein d'un prototype dédié. Les deux propositions sont évaluées à la fois quantitativement et qualitativement en utilisant une STCD de référence couvrant des glaciers du Groenland construite à partir de données optiques Landsat. Une autre STCD que nous avons construite à partir de données radar TerraSAR-X couvrant le massif du Mont-Blanc est également utilisée. Outre le fait d'être construites à partir de données et de techniques de télédétection différentes, ces séries se différencient drastiquement en termes d'indices de confiance, la série couvrant le massif du Mont-Blanc se situant à des niveaux de confiance très faibles. Pour les deux STCD, les méthodes proposées ont été mises en œuvre dans des conditions standards au niveau consommation de ressources (temps, espace), et les connaissances des experts sur les zones étudiées ont été confirmées et complétées<br>This PhD thesis deals with knowledge discovery from Displacement Field Time Series (DFTS) obtained by satellite imagery. Such series now occupy a central place in the study and monitoring of natural phenomena such as earthquakes, volcanic eruptions and glacier displacements. These series are indeed rich in both spatial and temporal information and can now be produced regularly at a lower cost thanks to spatial programs such as the European Copernicus program and its famous Sentinel satellites. Our proposals are based on the extraction of grouped frequent sequential patterns. These patterns, originally defined for the extraction of knowledge from Satellite Image Time Series (SITS), have shown their potential in early work to analyze a DFTS. Nevertheless, they cannot use the confidence indices coming along with DFTS and the swap method used to select the most promising patterns does not take into account their spatiotemporal complementarities, each pattern being evaluated individually. Our contribution is thus double. A first proposal aims to associate a measure of reliability with each pattern by using the confidence indices. This measure allows to select patterns having occurrences in the data that are on average sufficiently reliable. We propose a corresponding constraint-based extraction algorithm. It relies on an efficient search of the most reliable occurrences by dynamic programming and on a pruning of the search space provided by a partial push strategy. This new method has been implemented on the basis of the existing prototype SITS-P2miner, developed by the LISTIC and LIRIS laboratories to extract and rank grouped frequent sequential patterns. A second contribution for the selection of the most promising patterns is also made. This one, based on an informational criterion, makes it possible to take into account at the same time the confidence indices and the way the patterns complement each other spatially and temporally. For this aim, the confidence indices are interpreted as probabilities, and the DFTS are seen as probabilistic databases whose distributions are only partial. The informational gain associated with a pattern is then defined according to the ability of its occurrences to complete/refine the distributions characterizing the data. On this basis, a heuristic is proposed to select informative and complementary patterns. This method provides a set of weakly redundant patterns and therefore easier to interpret than those provided by swap randomization. It has been implemented in a dedicated prototype. Both proposals are evaluated quantitatively and qualitatively using a reference DFTS covering Greenland glaciers constructed from Landsat optical data. Another DFTS that we built from TerraSAR-X radar data covering the Mont-Blanc massif is also used. In addition to being constructed from different data and remote sensing techniques, these series differ drastically in terms of confidence indices, the series covering the Mont-Blanc massif being at very low levels of confidence. In both cases, the proposed methods operate under standard conditions of resource consumption (time, space), and experts’ knowledge of the studied areas is confirmed and completed

The great social and economic impact of earthquakes has made necessary the development of novel structural health monitoring (SHM) solutions for increasing the level of structural safety and assessment. SHM is the process of comparing the current state of a structure’s condition relative to a healthy baseline state to detect the existence, location, and degree of likely damage during or after a damaging input, such as an earthquake. Many SHM algorithms have been proposed in the literature. However, a large majority of these algorithms cannot be implemented in real time. Therefore, their results would not be available during or immediately after a major event for urgent post-event response and decision making. Further, these off-line techniques are not capable of providing the input information required for structural control systems for damage mitigation. The small number of real-time SHM (RT-SHM) methods proposed in the past, resolve these issues. However, these approaches have significant computational complexity and typically do not manage nonlinear cases directly associated with relevant damage metrics. Finally, many available SHM methods require full structural response measurement, including velocities and displacements, which are typically difficult to measure. All these issues make implementation of many existing SHM algorithms very difficult if not impossible. This thesis proposes simpler, more suitable algorithms utilising a nonlinear Bouc-Wen hysteretic baseline model for RT-SHM of a large class of nonlinear hysteretic structures. The RT-SHM algorithms are devised so that they can accommodate different levels of the availability of design data or measured structural responses, and therefore, are applicable to both existing and new structures. The second focus of the thesis is on developing a high-speed, high-resolution, seismic structural displacement measurement sensor to enable these methods and many other SHM approaches by using line-scan cameras as a low-cost and powerful means of measuring structural displacements at high sampling rates and high resolution. Overall, the results presented are thus significant steps towards developing smart, damage-free structures and providing more reliable information for post-event decision making.

After the excavation of a cut slope ongoing deformations on the slope surface can often be measured. These deformations can be induced due to various processes and can also be used as an indicator of slope stability. If the reasons for the deformations are known, selective stabilization methods can help to decelerate, or stop, the movements. The potential for the recognition of displacement patterns in excavated slopes is studied in this dissertation. In the laboratory, the analysis of displacement patterns due to various processes is difficult as identical initial test conditions can hardly be reproduced. Furthermore, measurements of displacements can only be conducted to a limited degree. Therefore, numerical calculations using the finite element method were applied to simulate excavation processes and analyse the displacements. In addition, a suitable mathematical model has to be used to represent the stress-strain behaviour during the unloading process. Three different advanced constitutive soil models were chosen to calculate an excavation process of an idealized slope assuming drained conditions: - elasto-plastic Modified-Cam-Clay model - rate-independent hypoplastic model according to Masin - rate-dependent visco-hypoplastic model according to Niemunis Before conducting the excavation simulation, the soil parameters of the constitutive models were calibrated by means of numerical element tests, depicting the stress paths of conventional laboratory tests. Within the literature, those conventional laboratory tests are recommended for the determination of parameters for the constitutive models. A parameter set for the visco-hypoplastic model was chosen from literature. The parameters were adapted for the remaining models. Thus, all three models predicted approximately the same stress-strain behaviour during conventional laboratory tests. Despite the correlations during the element tests, the constitutive models predicted different displacements during the calculation of the excavation of an idealized slope under drained conditions. Thereupon, load-controlled triaxial compression tests were conducted reproducing the characteristic stress paths during an excavation process. At the same time, numerical calculations were carried out to reproduce the triaxial compression tests, and the measured and calculated displacement behaviour was compared. Different processes such as pure unloading due to excavation, excavation in overconsolidated soil, excavation coupled with consolidation, excavation coupled with previous ground water lowering and consolidation as well as the influence of creep effects were considered in the analysis of the displacement patterns during an excavation. It can be stated that the evaluation of displacements and changes in displacements in a single point on the slope surface cannot provide sufficient information about a certain physical process. Only the combination of displacement paths at different survey points will lead to a reliable conclusion. Thus, representative displacement patterns for different processes are recognizable during and after the excavation, which can be used for the identification. During the numerical simulation of an in-situ model test, where a slope was brought to failure by excavation, the calculated displacements were analysed for identifiable displacement patterns. It can be stated that despite different slope systems, consistencies were found within characteristic survey points. These points can be used to identify patterns within the displacement contours.

博士<br>國立中正大學<br>地震研究所<br>92<br>The rheology of the Earth’s lithosphere is one of the important factors in causing time dependent deformation and stress variations following the large earthquake. For the analysis of tectonics beneath Taiwan, there is evidence to suggest that the lower crust underneath Taiwan display a ductile behavior. If so, then the ductile behavior of the lower crust must be involved in studies of postseismic deformations, transfer of stress and earthquake triggering. So far, this situation was never explored in this area. Consideration of models with viscous flow in the lower crust will help improve the understanding of information about the mechanics of controlling the time-dependent process and will be needed in order to accurately decipher this problem. The crust around the rupture zone of the 1999 Chi-Chi earthquake has tangible broad-scale postseismic deformations with a short relaxation time. In this work, we first study the mechanism of crustal early (97 days and 15 months after quake) postseismic deformation due to dip-slip earthquake. Taking into account the fault slip model, we calculate postseismic surface displacements caused by Chi-Chi earthquake in the central Taiwan using a three-dimensional finite element method for different assumed multi-layered Earth’s models. In order to determine the mechanism for early postseismic deformation and the evolution of stress for 2-year period following the earthquake the comparison of GPS data and theoretical calculations allows us to establish reasonable regional Earth’s model and rheological parameters of lower crust and upper mantle. Concerning the comparison of model result with real field observations, including spatial distribution of GPS surface measurements and aftershocks response to time dependent stress field, we could provide a more realistic rheological Earth’s model and explain phenomena previously not understood. Moreover, pattern dynamics will be applied to detect a non-local seismicity pattern prior to large-size earthquakes in Taiwan. We attempt to evaluate seismicity pattern of the future earthquake in Taiwan employing the catalogue for 1973-2000. Based on the exploration of the possible mechanism containing both the viscoelastic response model and the afterslip model in the early postseismic deformation of 1999 Chi-Chi quake, we compare theoretical surface displacements for each of the two models that we evaluate. The results reveal that there is little double, that while neither of these models alone are able to predict the GPS measurements well in a 97-day period, the combination of the two models improve the predictions considerably. We conclude that the afterslip mainly dominated Chi-Chi postseismic deformation in the rupture area, while the viscoelastic model did so elsewhere. Further consideration of tectonic loading in conjuction with postseismic deformation within the central Taiwan suggests that this effect may be negligible after 97 days, but it is significant for the long-term effect that we examined with 15-month GPS data. Combined with a Coulomb failure criterion we seek to validate our calculations of the static coseismic stress changes and time-dependent postseismic stress changes by comparing them to the observed seismicity rate changes associated with the Chi-Chi earthquake. In these calculations, we have considered the effect of a regional compressional stress field whose maximum principal axis is horizontal and oriented N119°E. The results show that static coseismic stress changes explain the apparent triggering of aftershocks by mainshock, especially those that occurred in the upper crust after the first several Maxwell times of the mainshock. The relaxation of the stress in the lower part of the crust can transfer stress up to the upper crust with a roughly steady rate. This means that the viscoelastic relaxation may be responsible for the triggering of aftershocks in the upper part (10 km) of crust in the long term. Finally, we investigate the non-local seismicity patterns in Taiwan by pattern dynamics. Most of the larger-size earthquakes occurred in areas of probability increase, yielding evidence for space-time patterns of seismic activity which reflect the existence of correlations in underlying stress or strain field.

碩士<br>國立臺灣大學<br>土木工程學研究所<br>104<br>In this stage, the analysis of tunnels is based on the study of “stress-strain relationship around a hole in an elasto-plasticity media” and “closed convergence curve concept”. These theories of underground excavation are mostly proposed by European and American countries. Because of their old geological ages and high strength and excellent cement of rock mass, the tunnels there can be operated stably as long as the construction is fully completed. However, the tunnels constructed in Japan and Taiwan, are deformed to give some impacts to their operation, due to the young geological ages of Japan and Taiwan. Thus, the theories above cannot be fully applied in the cases in Taiwan, and how to keep the operation of tunnels stable becomes one important issue in tunnel engineering of Taiwan. In the tunnel, there are different kinds of defect can be observed on the lining, for the reason that there are various kinds of way to detect the tunnel. The most common issue in the operation of tunnels is how to deal with cracks on the linings. Since the patterns of cracks seem related to the relevant causes, it is generally viewed as an effective way to deal with the cracks for maintaining tunnels in operation by observing, recording and explaining the pattern and development of cracks. In this study, one finite element model with one tunnel and the surrounding rock mass is proposed to survey the relationship between the patterns of cracks and different conditions of displacements of lining induced by the movements of surrounding rock mass. Besides, the impacts of different cross-section geometry and length of tunnels, different number of construction joints and stiffness of surrounding rock mass to the development of cracks are investigated, and one case study is demonstrated. The results show that the different conditions of displacements of surrounding rock mass would induce distinct patterns of cracks of linings, and the crack patterns would not alter caused by different condition of tunnels. The case study also shows that the patterns and the positions of cracks on the model in this study are consistent with the in-situ record.

碩士<br>國立中正大學<br>機械系<br>91<br>This research presents the construction and operation of an electronic speckle pattern interferometer (ESPI) applied to sandwich plates with inserts. Proposed ESPI is a full-field and non—destructive testing that can measures tiny out-of-plane displacement in the elastic region, without wasting specimen. ESPI has never been applied on measurement of sandwich plates with inserts. In the experiment of this study, a modified Michelson interferometer is shown. There are two results of the experiment in this study. The first result indicates that the strength of single-inserted sandwich will increase as the diameter of potting material is increasing, but having the penalty of weight increase. The second result indicates that the out-of-plane displacements for two-inserted sandwich loaded by the same forces will decrease as the spatial interval of the two inserts is increasing. For validation purpose, the finite element method (FEM) analysis was introduced to compare with the result of ESPI. Comparison between the results of ESPI and FEM revealed a convincing agreement. The results of this study could be applied on designing the sandwich with inserts in the future.

碩士<br>國立臺灣大學<br>生態學與演化生物學研究所<br>101<br>Character displacement hypothesis states: when species with character similarity coexist in the same community, the population in sympatric location would displace in one or more characters. The increased differences in character space would reduce the strength of inter-specific competition for limited resources. Both Japalura swinhonis and Japalura polygonata xanthostoma occur in northern Taiwan. The two congeners have similar morphology and ecology, yet different macro-habitats. I applied species distribution model to identify environmental features that describe their differences in macrohabitat use, and predict the potential contact zone of the two species. Then use the latter to examine the pattern of character displacement. The results of species distribution modeling showed the distance to human-use area and total area of forest contribute the most to the distribution of the two species. The models allowed me to successfully locate four main regions of species coexistence. I found evidence for character displacement in most sympatric locations of Japalura swinhonis and Japalura polygonata xanthostoma. In four of the sympatric locations I surveyed, three of them showed significant intra-specific differences in their morphology between sympatric and allopatric locations. The head related parameters were consistently smaller for both species. While inter-specific difference of bite force related characters were greater in the sympatric than allopatric locations, characters related to sprint speed were more similar in the sympatric locations. Character displacement may be effect by inter-specific competition and predation risk in sympatric location, therefore, the characters related to sprint speed would be more similar.

碩士<br>國立中正大學<br>機械工程所<br>94<br>Sandwich honeycomb structures are used extensively for aircraft structures and flying vehicles, due to which have the advantage of characteristic for low mass and could be accept higher strength, and structure of the sandwich honeycomb plate with potting material and insert which can increase the strength of the structure, improve the local stress concentration and increase the loading point. This research presents the construction and operation of an electronic speckle pattern interferometry (ESPI) applied to sandwich plates with inserts. Proposed ESPI is a full-field and non-destructive testing that can measures tiny out-of-plane and in-plane displacement in the elastic region. The experimental construction is to integrate out-of-plane and in-plane measurement into an optical system, to measure the three-dimensional displacement of the sandwich plates. There are two main results of the experiment. The first result indicates that the strength of the sandwich plate will increase as the core thickness is increasing, but the displacement will decrease. The second result indicates that the displacement will decrease as the diameter of insert is increasing, but the strength will increase. For validation purpose, the analytical analysis was introduced to compare with the result of ESPI. Comparison between the results of ESPI and analytical revealed a convincing agreement. The results of this study could be applied on designing the sandwich structure with insert in the future.