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[pt] O presente estudo propõe modelos numéricos robustos para simular os fenômenos presentes nos problemas de propagação de fraturas e migração de fluidos em formações fraturadas. Uma técnica de fragmentação de malha com uma abordagem de zona poro-coesiva é desenvolvida para simular a propagação não planar de fraturas em formações fraturadas. O modelo proposto permite estudar os efeitos dos parâmetros primários sobre a interação de fraturas hidráulicas e naturais. O trabalho desenvolve uma nova formulação hidromecânica 3D do dupla porosidade e dupla permeabilidade aprimorada para a representação mais realista do médio fraturado em simulações de reservatório. O modelo permite estudar o impacto de fraturas naturais de múltiplas escalas e orientações no desempenho do reservatório. Finalmente, o trabalho propõe uma nova metodologia que integra os modelos robustos de propagação de fratura e simulação de reservatório, para aprimorando a avaliação do desempenho da produção. Foram simulados múltiplos cenários de fraturamento hidráulico para avaliar a produção dos reservatórios. Também foram integrados modelos de fratura discreta e dupla porosidade-dupla permeabilidade para estudar os efeitos de fraturas de múltiplas escalas no reservatório estimulado hidraulicamente. Os modelos desenvolvidos foram comparados com testes experimentais, soluções analíticas e numéricas. Os resultados mostram excelente concordância e validam as formulações hidromecânicas. A partir dos resultados numéricos, se identificaram os parâmetros dominantes que influenciam o resultado do fraturamento hidráulico e a produção dos depósitos hidraulicamente estimulados. / [en] The presented study proposes robust numerical models to simulate the phenomena present in fracture propagation and fluid migration problems in fractured media. An innovative mesh fragmentation technique with an intrinsic pore-cohesive zone approach is developed to simulate unrestricted hydraulic fracture propagation in fractured media. The proposed method allows studying the effect of some primary parameters on hydraulic and natural fracture interaction. A new 3D hydromechanical formulation for an enhanced dual-porosity/dual-permeability model is proposed to represent a fractured porous formation more realistically in reservoir simulations. The new model allows the study of the impacts of natural fractures with different orientations at multiple scales on the hydromechanical behavior of the reservoir. Finally, this research work proposes a new methodology that integrates a robust fracture propagation model and reservoir simulation, improving the evaluation of production performance. We simulate several hydraulic fracturing scenarios for the assessment of the cumulative production of the reservoir. Moreover, we combined discrete fracture and enhanced dual porosity-dual permeability models to study the effects of fractures of multiple lengths on the hydraulically stimulated reservoir. The developed models are compared against experimental tests, analytical and numerical solutions. The comparative results show excellent agreement and validate the fully coupled hydromechanical formulations. From the numerical results, it was possible to identify the dominant parameters that influence hydraulic fracturing and the production performance of the hydraulically stimulated deposits.

Cette thèse fait l'étude expérimentale de dynamiques de relaxations ultrarapides au sein d'atomes et de molécules (Ar, NO2, C2H2). Les méthodes expérimentales qui sont utilisées sont basées sur l'interaction d'un rayonnement laser avec le système atomique ou moléculaire étudié et font intervenir le processus de génération d'harmoniques d'ordres élevés, ainsi que la spectrométrie d'imagerie de vecteur vitesse. Au cours de cette thèse, deux approchesexpérimentales de type pompe-sonde ont été mises en œuvre. Une première approche exploitela sensibilité du processus de génération d'harmoniques à la structure électronique dumilieu pour la sonder. Cette méthode a été utilisée sur la molécule de dioxyde d'azote pourobserver sa relaxation électronique à travers l'intersection conique des états X2A1-A2B2suite à une excitation autour de 400 nm. Une seconde approche utilise le rayonnementharmonique comme source de photons dans le domaine de l'extrême ultraviolet (EUV)pour exciter ou sonder les espèces d'intérêt. Cette approche a été couplée avec l'utilisationd'un spectromètre d'imagerie de vecteur vitesse (VMIS), qui a été développé durant lathèse. Des expériences menées sur un système modèle comme l'argon ont permis de validerle dispositif expérimental, qui a ensuite été mis en application pour étudier la photodissociationde la molécule d'acétylène, après excitation autour de 9,3 eV du complexe deRydberg 3d-4s. Les deux méthodes mises en œuvre permettent toutes-deux de réaliserdes études dynamiques résolues en temps à l'échelle femtoseconde. / Ultrafast atomic and molecular dynamics (Ar, NO2, C2H2) have been experimentally studied during this PhD. The employed techniques use the laser interaction with the atomic or molecular system produced in gas phase. High harmonic generation (HHG) pump-probe studies allow resolving dynamics on a femtosecond scale. Two applications of high harmonic generation have been implemented here. In the first one, the harmonic generation process is the probe of a vibronic relaxation induced by a pump pulse. This application is currently labeled high harmonic spectroscopy. The sensibility of the high harmonic process to the geometry of the atomic or molecular orbitals is exploited to obtain information about the electronic structure of the generating medium. This method have been used to reveal the electronic relaxation of the nitrogen dioxide molecule (NO2) through the X2A1-A2B2 conical intersection.A second way consists to use the harmonic radiation like a source of XUV photons. The produced XUV radiation permits thus to reach electronically excited energy levels of atoms or molecules, pumping only with a one photon transition. XUV photons can also be used like a probe to ionize products of a molecular reaction. Velocity map imaging spectrometer (VMIS) have been designed and built to complete this fs-VUV source. Above threshold ionization (ATI) experiments and pump-probe XUV-400 nm studies have been performed on reference system like Argon to characterize the built experimental setup. The last excitation scheme has been also applied to study the photodissociation of the Acetylene excited in the 3d-4s Rydberg complex.

在無線網狀網路(Wireless Mesh Network)中，每個節點須幫助相鄰節點轉送資料及提供使用者網路存取，例如WLAN(IEEE 802.11s)、WMAN(IEEE 802.16)等，皆可利用多跳接方式將資料轉送至通訊閘道器(Gateway)。在無線網狀網路中，常利用密集佈建的方式來解決通訊死角的問題。當網路節點的密度增加時，無線訊號的干擾也會增強，並且各節點的效能會顯著下降。 在本研究中，將利用幾何學概念，解決網路干擾問題，並提出拓樸重建演算法來重建路徑，使網路干擾達到最小化。我們試著最小化節點與節點間的干擾，以提升整體無線網狀網路效能。我們將網路問題轉換成幾何問題，並定義在幾何圖形中線段交錯問題，之後驗證在幾何圖形中是否有線段交錯的現象發生。若發生線段交錯時，則將此線段從幾何圖形中移除，並且利用三角化演算法將此區域線段重新規劃，使相鄰節點間的干擾最小。當網路拓樸建立完成後，我們利用標準差公式將干擾較大的連線移除，使得網路效能提升。上述測試線段交錯及三角化多邊形演算法可在時間複雜度O(n log n)內找到干擾最小的解。最後，我們將利用網路模擬器(Network Simulator)驗證所提出的方法是否能達到預期的系統效能指標。 / In wireless mesh networks, such as WLAN (IEEE 802.11s), WMAN (IEEE 802.16), etc., each node should forward packets of neighboring nodes toward gateway using multi-hop routing mechanism. In wireless mesh network, as the density of network nodes increases, the RF interference will increase and the throughput of each node will drop rapidly. In our research, we use the geometry to resolve the RF interference problem by rebuilding network topology. We try to minimize the interference between neighboring nodes and improve the throughput in wireless mesh network. We transform the network topology problem into geometry problem and define the line intersection problem in geometric graph, then check path intersection in the geometric graph. If line intersection occurs in the graph, we remove the intersection line from the graph and re-plan the region by triangulation algorithm. When the network topology is built up, we use a standard deviation formula to improve network performance by removing longer links. The line intersection algorithm and triangulation algorithm, both of time complexity O(n log n), are used to find the minimal interference solution. At the end of our research, we use network simulator to verify if the proposed methods can help to meet all those performance expectations.

Cette thèse fait l'étude expérimentale de dynamiques de relaxations ultrarapides au sein d'atomes et de molécules (Ar, NO2, C2H2). Les méthodes expérimentales qui sont utilisées sont basées sur l'interaction d'un rayonnement laser avec le système atomique ou moléculaire étudié et font intervenir le processus de génération d'harmoniques d'ordres élevés, ainsi que la spectrométrie d'imagerie de vecteur vitesse. Au cours de cette thèse, deux approchesexpérimentales de type pompe-sonde ont été mises en œuvre. Une première approche exploitela sensibilité du processus de génération d'harmoniques à la structure électronique dumilieu pour la sonder. Cette méthode a été utilisée sur la molécule de dioxyde d'azote pourobserver sa relaxation électronique à travers l'intersection conique des états X2A1-A2B2suite à une excitation autour de 400 nm. Une seconde approche utilise le rayonnementharmonique comme source de photons dans le domaine de l'extrême ultraviolet (EUV)pour exciter ou sonder les espèces d'intérêt. Cette approche a été couplée avec l'utilisationd'un spectromètre d'imagerie de vecteur vitesse (VMIS), qui a été développé durant lathèse. Des expériences menées sur un système modèle comme l'argon ont permis de validerle dispositif expérimental, qui a ensuite été mis en application pour étudier la photodissociationde la molécule d'acétylène, après excitation autour de 9,3 eV du complexe deRydberg 3d-4s. Les deux méthodes mises en œuvre permettent toutes-deux de réaliserdes études dynamiques résolues en temps à l'échelle femtoseconde.

The geometrical structure of a tree can consist of thousands, even millions, of branches, twigs and leaves in complex arrangements. The structure contains a lot of useful information and can be used for example to assess a tree's health or calculate parameters such as total wood volume or branch size distribution. Because of the complexity, capturing the structure of an entire tree used to be nearly impossible, but the increased availability and quality of particularly digital cameras and Light Detection and Ranging (LIDAR) instruments is making it increasingly possible. A set of digital images of a tree, or a point cloud of a tree from a LIDAR scan, contains a lot of data, but the information about the tree structure has to be extracted from this data through analysis. This work presents a method of reconstructing 3D models of trees from point clouds. The model is constructed from cylindrical segments which are added one by one. Bayesian inference is used to determine how to optimize the parameters of model segment candidates and whether or not to accept them as part of the model. A Hough transform for finding cylinders in point clouds is presented, and used as a heuristic to guide the proposals of model segment candidates. Previous related works have mainly focused on high density point clouds of sparse trees, whereas the objective of this work was to analyze low resolution point clouds of dense almond trees. The method is evaluated on artificial and real datasets and works rather well on high quality data, but performs poorly on low resolution data with gaps and occlusions.

This thesis presents a safety inspection in selected places in the Vysocina region of the Czech Republic. Six intersections in rural and municipal areas, plus three rural road sections were selected for the inspection and an accident rate analysis. The places selected were compared in terms of the accident rate and one case of each group was then selected for a detailed safety inspection encompassing visual inspection and identification of possible hazards. By eliminating such safety hazards, it is possible to ensure a traffic fluency and to preclude traffic accidents or at least minimize the harm caused by it.

This diploma thesis deals with the proposal of an alternative solution to the intersection of Mohelnice North crossroads. It compares the current junction design, which is considered inappropriate, with two new proposals for circular intersections. The aim of the thesis is to propose the resultant junction cheaper, smaller and simpler for users.

The thesis deals with design of the tram power collecting route and the tram track of the route no. 3 in reconstruction area recently called “Zbrojovka Brno”. Connection to the present infrastructure is also considered. Housing, resting, administration sectors and tram stops are designed for easy availability in the new area. Because the railroad bounds the area on the East and will be extended in the future, joining the tram transport with integrated transport system in Židenice is possible. Design includes the new bridge across Svitava river and connection with surrounding areas. If we divide individual car transport (IAD) from the tram route, the trolley car transportation is designed in place IAD.