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Description de contenu vidéo : mouvements et élasticité temporelle / Description of video content : motion and temporal elasticityBlanc, Katy 17 December 2018 (has links)
La reconnaissance en vidéo atteint de meilleures performances ces dernières années, notamment grâce à l'amélioration des réseaux de neurones profonds sur les images. Pourtant l'explosion des taux de reconnaissance en images ne s'est pas directement répercuté sur les taux en reconnaissance vidéo. Cela est dû à cette dimension supplémentaire qu'est le temps et dont il est encore difficile d'extraire une description robuste. Les réseaux de neurones récurrents introduisent une temporalité mais ils ont une mémoire limitée dans le temps. Les méthodes de description vidéo de l'état de l'art gèrent généralement le temps comme une dimension spatiale supplémentaire et la combinaison de plusieurs méthodes de description vidéo apportent les meilleures performances actuelles. Or la dimension temporelle possède une élasticité propre, différente des dimensions spatiales. En effet, la dimension temporelle peut être déformée localement : une dilatation partielle provoquera un ralentissement visuel de la vidéo sans en changer la compréhension, à l'inverse d'une dilatation spatiale sur une image qui modifierait les proportions des objets. On peut donc espérer améliorer encore la classification de contenu vidéo par la conception d'une description invariante aux changements de vitesse. Cette thèse porte sur la problématique d'une description robuste de vidéo en considérant l'élasticité de la dimension temporelle sous trois angles différents. Dans un premier temps, nous avons décrit localement et explicitement les informations de mouvements. Des singularités sont détectées sur le flot optique, puis traquées et agrégées dans une chaîne pour décrire des portions de vidéos. Nous avons utilisé cette description sur du contenu sportif. Puis nous avons extrait des descriptions globales implicites grâce aux décompositions tensorielles. Les tenseurs permettent de considérer une vidéo comme un tableau de données multi-dimensionnelles. Les descriptions extraites sont évaluées dans une tache de classification. Pour finir, nous avons étudié les méthodes de normalisation de la dimension temporelle. Nous avons utilisé les méthodes de déformations temporelles dynamiques des séquences. Nous avons montré que cette normalisation aide à une meilleure classification. / Video recognition gain in performance during the last years, especially due to the improvement in the deep learning performances on images. However the jump in recognition rate on images does not directly impact the recognition rate on videos. This limitation is certainly due to this added dimension, the time, on which a robust description is still hard to extract. The recurrent neural networks introduce temporality but they have a limited memory. State of the art methods for video description usually handle time as a spatial dimension and the combination of video description methods reach the current best accuracies. However the temporal dimension has its own elasticity, different from the spatial dimensions. Indeed, the temporal dimension of a video can be locally deformed: a partial dilatation produces a visual slow down during the video, without changing the understanding, in contrast with a spatial dilatation on an image which will modify the proportions of the shown objects. We can thus expect to improve the video content classification by creating an invariant description to these speed changes. This thesis focus on the question of a robust video description considering the elasticity of the temporal dimension under three different angles. First, we have locally and explicitly described the motion content. Singularities are detected in the optical flow, then tracked along the time axis and organized in chain to describe video part. We have used this description on sport content. Then we have extracted global and implicit description thanks to tensor decompositions. Tensor enables to consider a video as a multi-dimensional data table. The extracted description are evaluated in a classification task. Finally, we have studied speed normalization method thanks to Dynamical Time Warping methods on series. We have showed that this normalization improve the classification rates.
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Towards Malleable Distributed Storage Systems˸ From Models to Practice / Malléabilité des Systèmes de Stockage Distribués ˸ Des Modèles à la PratiqueCheriere, Nathanaël 05 November 2019 (has links)
Le Cloud, avec son modèle économique, offre la possibilité d’un gestion élastique des ressources; les utilisateurs peuvent louer des ressources selon leurs besoins. Cette élasticité permet de réduire les coûts énergétiques et financiers, et aide les applications à s’adapter aux charges de travail variables.Les applications manipulant de grandes quantités de données exécutées dans le Cloud ou sur des supercalculateurs sont souvent colocalisées avec un système de stockage distribué pour garantir un accès rapide aux données. Bien que de nombreux travaux aient été proposés pour redimensionner dynamiquement les capacités de calcul pour s’ajuster à la charge de travail, le stockage n’est pas considéré comme malléable (capable d’être redimensionné dynamiquement) puisque les transferts de grandes quantités de données nécessaires sont considérés trop lents. Cependant, le matériel et les techniques de stockage ont évolué et cette hypothèse doit être réévaluée.Dans cette thèse, nous présentons une étude sous différents angles des opérations de redimensionnement des systèmes de stockage distribués.Nous commençons par modéliser la durée minimale de ces opérations pour évaluer leur vitesse potentielle. Puis, nous développons un benchmark conçu pour mesurer la viabilité de la malléabilité d’un système de stockage sur une plateforme donnée. Finalement, nous implémentons un gestionnaire d’opérations de redimensionnement pour systèmes de stockage distribués qui décide et organise les transferts de données requis par ces opérations. / The Cloud, with its pay-as-you-go model, gives the possibility of elastic resource management; users can claim and release resources as needed. This elasticity leads to financial and energetical cost reductions, and helps applications to cope with varying workloads.Distributed cloud and HPC applications processing large amounts of data are often co-located with a distributed storage system in order to ensure fast data accesses. Although many works have been proposed to dynamically rescale the processing part of such systems to match their workload, the storage is never considered as malleable (able to be dynamically rescaled) since moving massive amounts of data around is assumed to be too slow in practice. However, in recent years hardware and storage techniques have evolved and this assumption needs to be revisited.In this thesis, we present a study of the rescaling operations in distributed storage systems approached from different angles. We start by modeling the minimal duration of rescaling operations to estimate their potential speed. Then, we develop a benchmark to measure the viability of distributed storage system malleability on a given platform. Last, we implement a rescaling manager for distributed storage systems that decides and organizes the data transfers required during a rescaling operation.
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CoCoS - Computation of Corner SingularitiesPester, Cornelia 06 September 2006 (has links)
This is a documentation of the software package COCOS. The purpose of COCOS is the computation of corner singularities of elliptic equations in polyhedral corners and crack tips. COCOS provides a self-contained library for the generation of structured 2D finite element meshes, including various routines for mesh manipulation, as well as several algorithms for the solution of quadratic eigenvalue problems with Hamiltonian structure. These and further features will be described in this documentation.
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Semiflexible Polymer Networks and Persistence Length: Macroscopic vs. Microscopic ElasticitySchuldt, Carsten 01 October 2018 (has links)
In der vorliegenden Arbeit wird die Mechanik von Netzwerken semiflexibler Polymere behandelt. Insbesondere wird der Zusammenhang zwischen der Steifigkeit des Einzelfilaments und der Steifigkeit des Gesamtnetzwerks experimentell untersucht.
Der Hintergrund aktueller, einschlägiger theoretische Modelle wird zusammengefasst. Die Möglichkeiten und Limitierungen bisheriger experimenteller Modellsysteme werden diskutiert. Zur Untersuchung des eingangs genannten Zusammenhangs wird ein neuartiges, vielfältiges Modellsystem für semiflexible Polymere auf Basis von DNA Röhren
eingeführt und umfassend auf Einzelfilament- und Netzwerkebene charakterisiert. Die Steifigkeit des Netzwerks lässt sich damit und unter Einsatz von Quervernetzern über einen weiten Bereich einstellen.
Es zeigt sich, dass bisherige einschlägige Modelle in der korrekten Vorhersage des o.g. Zusammenhangs scheitern. Mögliche Auswege in der Modellierung werden skizziert, sowie konkrete, weitere Anwendungen der DNA Röhren benannt.:Chapter 1 Introduction
Chapter 2 Background
Section 2.1 Theoretical Models
Section 2.2 Rheology
Section 2.3 Experimental Model Systems
Section 2.4 Existing G_0(l_p) Studies
Chapter 3 Materials & Methods
Section 3.1 Microscopy
Section 3.2 Atomic Force Microscopy
Section 3.3 Shear Rheology
Section 3.4 Actin
Section 3.5 DNA Assembly
Section 3.6 Statistical Analysis Tools
Chapter 4 Results
Section 4.1 Persistence Length of Individual Filaments
Section 4.2 Entangled Networks
Section 4.3 Reptation
Section 4.4 Inextensibility
Section 4.5 Cross-Linked DNA n-Helix Tubes
Chapter 5 Discussion
Section 5.1 Limitations of Established Semiflexible Model Systems
Section 5.2 DNA $n$-Helix Tubes as a Tunable Model System
Section 5.3 Validation as an Entangled Semiflexible Model System
Section 5.4 Impact on Existing Theories
Section 5.5 DNA n-Helix Tubes as a Tunable Material
Section 5.6 Summary
Section 5.7 Outlook
Chapter A Further Calculations
Section A.1 Detailed Calculations on Worm-Like Chains.
Chapter B Protocols
Section B.1 Actin
Section B.2 DNA n-Helix Tubes
Chapter Bibliography
Chapter List of Own Publications
Chapter Acknowledgments
Chapter Zusammenfassung nach §11(4) Promotionsordnung
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Vliv hyperkinetické zátěže na vybrané mechanické změny axiálního systému člověka. / Influence of Hyperkinetic Load on Selected Mechanical Changes of Human Axial System.Panská, Šárka January 2019 (has links)
Title: Influence of Hyperkinetic Load on Selected Mechanical Changes of Human Axial System. Objectives: The main aim of this thesis is to determine the influence of hyperkinetic load on the change of selected mechanical properties of the rhythmic gymnastic axial system based on the sophisticated use of the Transfer Vibration through Spine (TVS) method. Methods: The following experimental methods were used to identify changes in rheological properties of AS and to assess load intensity: 1) TVS method; 2) software for evaluating and analyzing vibration tests of heterogeneous systems; 3) kinematic and dynamic motion analysis using: 2D motion video recording, QUALISYS 3D motion analysis system, KISTLER, to analyze dynamic human-surroundings interactions. Results: Pilot studies and the main experimental part of the thesis have shown that the use of the TVS method can identify both short-term and longitudinal changes of AS mechanical properties. Due to the hyperkinetic load, the selected mechanical properties of the rhythmic AS are changed. The gymnastic apparatus reacts to the training load by reducing the rheological parameters, especially the damping coefficient b and the viscosity µ. After regeneration, which is on the following day, the parameters return to the default values. The impact load...
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Efekt kosmetických přípravků s různým pH na vlastnosti kůže mužů a žen / The effect of cosmetic products with different pH on the skin properties of men and womenDrabová, Veronika January 2019 (has links)
The aim of this diploma thesis was to summarize the basic knowledge of human skin and it's biophysical parameters. Attention was focused on influence of cosmetic products with different pH on the change of skin parameters especially. The first part describes the anatomical and histological structure of the skin, it's basic functions and development. In the following chapters of this work is mentioned physiological representation of microorganisms found on the skin surface and general characteristics of cosmetic products. There are used in everyday skin care that affect the natural skin surface pH value. Optimum surface pH is important for the proper functioning of human skin. The final chapters of the described the characteristics of the basic biophysical parameters of the skin (hydration, TEWL, pH, sebum) and methods for their measurement. Key words: skin, transepidermal water loss, pH, hydration, sebum, microbiome
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Textile Hybrids : Exploring knitted textiles by challenging properties of elasticity and flexibility through combinations with wood.Becerra Venegas, Francisca January 2020 (has links)
Textile Hybrids explores knitted textiles by challenging properties of elasticity and flexibility through yarn composition, technical construction and combinations with wood. This study is placed in the field of textile spatial design and suggests experimental ways to explore three-dimensionality in a knitted textile by changing its properties through material synergies. The outcome is a three piece series of modular three-dimensional, standalone textile objects. The construction, assembly and flexibility of each piece make it possible to separate all components for reassembly, recycling or reusing, suggesting further research possibilities into more tangible contexts within textile spatial design, architecture, furniture design and product design. This study is derived from an interest to explore different ways a textile can exist on its own in a spatial context such as the home, without solely being the material covering a load-bearing framework i.e a couch or a chair.
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Health in the Developing World : A panel data study on the determinants of health expenditures in the world’s least developed countriesBergman, Johan January 2020 (has links)
The determinants of health expenditures have been studied extensively for the past 50 years and income has been seen as the major driver. The focus has rarely left developed countries which raises the question as to whether the same positive relationship exists in developing countries as well. The purpose of this thesis is to answer this question by conducting a fixed effect regression on a sample of 38 countries labelled as the least developed in the world by the United Nations with data stretching between 2000 to 2017. The results indicate a weaker relationship in the sample compared to estimates on developed countries. However, due to a lack of theoretical guidance on how health expenditures are determined and indications that omitted variable bias is present, the results do not provide definitive conclusions.
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Stabilisering av betongstommar : Beräkning av en ekvivalent beräkningsmodul med hänsyn till samverkande kort- och långtidslast / Stabilization of concrete structures : Calculation of an equivalent modulus of elasticity taking into account interaction of short- and long-term loadsPersson, Anna, Strand, Martin January 2013 (has links)
Vid stabilisering av betongstommar är det komplicerat att välja en korrekt elasticitetsmodul. Detta då stommens laster verkar under både kort och lång tid. I detta examensarbete utförs en noggrann kryptalsberäkning för varje plans vertikala element, där hänsyn tas till den varierande byggtiden. Utifrån det analyseras kort- och långtidslaster med respektive elasticitetsmodul för att erhålla en ekvivalent elasticitetsmodul som tar hänsyn till de olika belastningstiderna. Denna elasticitetsmodul bestäms efter förhållandet mellan stommens knäcksäkerhet, snedställning och den vindlast som verkar på byggnaden. Den ekvivalenta elasticitetsmodulen ligger till grund för mer noggrann indata än tidigare vid stabilitetsberäkningar och redovisas i diagram som sedan kan användas i det praktiska ingenjörsarbetet. Där inget annat anges utförs beräkningar enligt Eurokod 2.Där inget annat anges är figurerna ritade av författarna. / When considering stabilization of concrete structures it is difficult to assign a correct modulus of elasticity to the structure. This is due to the presence of both short- and long-term loads. In this thesis a detailed calculation of each vertical elements creep coefficient is performed, which takes into account the varying construction time. Furthermore short and long term loads with respective modulus of elasticity are analyzed to obtain an equivalent modulus of elasticity corresponding to the two previously mentioned. The equivalent modulus of elasticity is determined by the relationship between the buckling resistance of the structure, initial imperfections and the wind load acting on the building. The equivalent modulus of elasticity is the basis for a more accurate input for stability calculations and is presented in graphs that can be used in the practice of engineering. Unless otherwise stated, calculations are performed according to Eurocode 2.Unless otherwise stated, the figures are drawn by the authors.
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Soil-structure interaction for integral bridges and culvertsBayoglu Flener, Esra January 2004 (has links)
No description available.
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