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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
721

Mobility Management in New Internet Architectures / Gestion de la mobilité IP dans les nouvelle architectures Internet

Tantayakul, Kuljaree 17 September 2018 (has links)
L’intégration logicielle avec les nouvelles architectures réseau via l’axe SDN (Software-Defined Network) apparaît comme une évolution majeure des réseaux. Bien que ce paradigme ait été principalement développé pour faciliter la configuration du réseau, sa capacité à intégrer les services doit également être prise en compte. Ainsi, le service de mobilité pour lequel des solutions ont été proposées dans des architectures classiques en définissant des protocoles normalisés devrait être repensé en termes de service SDN. Les appareils mobiles peuvent utiliser ou se déplacer dans le réseau SDN. Dans cette thèse, nous avons propose une nouvelle approche de gestion de la mobilité appelée "SDN-Mobility" et montré que SDN peut alors sans protocole de mobilité IP fournir une mobilité comme Proxy Mobile IPv6 (PMIPv6) qui est la solution adoptée par 3GPP, avec un gain de performance. Toutefois, PMIPv6 et SDN-Mobility présentent des pertes de paquets lors du transfert du noeud mobile (MN). Ainsi, dans cette thèse, nous avons proposé un nouveau paradigme basé sur la fonction de mise en cache pour améliorer la qualité du transfert lors du déplacement du mobile. La stratégie de mise en cache coopère avec le contrôleur SDN pour la mise en mémoire tampon automatique des données pendant le transfert. Nous avons proposé deux politiques de mise en cache qui sont comparées à travers une analyse de performance concernant la qualité du transfert pour l’utilisateur et pour l’opérateur. Cette thèse a également présenté que SDN-Mobility avec la politique de mise en cache peut être facilement appliquée pour gérer la mobilité dans des architectures de réseau hétérogènes capables d’intégrer le futur Internet basé sur les réseaux centrés sur l’information (ICN). / The software integration with new network architectures via Software-Defined Networking (SDN) axis appears to be a major evolution of networks. While this paradigm was primarily developed for easy network setup, its ability to integrate services has also to be considered. Thus, the mobility service for which solutions have been proposed in conventional architectures by defining standardized protocols should be rethought in terms of SDN service. Mobile devices might use or move in SDN network. In this thesis, we proposed a new mobility management approach which called "SDN-Mobility" and has shown that SDN can be implemented without IP mobility protocol for providing mobility like as Proxy Mobile IPv6 (PMIPv6) that is the solution adopted by 3GPP, with some performance gain. However, PMIPv6 and SDN-Mobility have some packets loss during Mobile Node (MN) handover. Thus, in this thesis, we proposed a new paradigm based on caching function to improve the quality of transfer during handover. Caching policy cooperates with SDN controller for automatic buffering of the data during the handover. We proposed two caching policies that are compared through a performance analysis regarding the quality of transfer for the user and for the operator. This thesis also presented that SDN-Mobility with caching policy can be applied easily for mobility management in heterogeneous network architectures able to integrate the future Internet based on the Information-Centric Networking (ICN).
722

Mobilidade intergeracional de educação no Brasil / Intergenerational schooling mobility in Brazil

Paschoal, Izabela Palma 14 February 2008 (has links)
Estudos sobre mobilidade intergeracional de educação sugerem que países subdesenvolvidos apresentam menor mobilidade intergeracional que países desenvolvidos e especificamente para o Brasil, o grau de persistência estimado é ao redor de 0.7, podendo apresentar diferentes graus ao longo da distribuição de educação. Este estudo apresenta uma nova abordagem para a mensuração da mobilidade intergeracional utilizando Regressões Quantílicas. Especificamente, é proposta uma medida de distância entre os quantis condicionais para analisar a mobilidade intergeracional. Como resultado, é obtido um conjunto de matrizes que descrevem o padrão da mobilidade intergeracional em diferentes pontos da distribuição condicional de escolaridade. Utilizando dados para o Brasil, encontra-se que a mobilidade intergeracional tende a ser maior nas caudas da distribuição de escolaridade para filhos e filhas relativo à educação de pais e mães. Comparando filhos e filhas, os filhos tendem a ter menor mobilidade intergeracional que as mulheres relativo à educação de seus pais. Além do mais, a educação das mães tem maior efeito em magnitude do que a educação dos pais tanto para filhos quanto para as filhas. Também se encontrou que a educação dos filhos depende mais da educação do pai e a educação das filhas depende mais da educação das mães, indicando que os filhos tendem a ter educação similar à de seus pais e as filhas tendem a ter educação similar à de suas mães. / Studies on intergenerational educational mobility suggest that underdevelopment countries presents lower intergenerational mobility than developed countries and specifically for Brazil, the estimated degree of persistence is around 0.7 with possible different degrees on the overall distribution of education. This study presents a new approach to measuring intergenerational mobility using quantile regression. Specifically, it is proposed the use of a measure of distance between conditional quantiles to analyze intergenerational mobility. As a result, is obtained a set of matrices which describe the patterns of intergenerational mobility at different points of the conditional distribution of schooling. Using Brazilian Data (PNAD 1996) it is found that intergenerational mobility seems to be higher at the tails of the distribution of schooling for sons and daughters relative to father\'s and mother\'s education. Comparing each other, sons tend to have less mobility than daughters relative to father\'s education. Moreover, mother\'s education has stronger effects than father\'s on both sons and daughters education. It was also found that son\'s education depends more on father\'s education and daughter\'s education depends more on mother\'s education, indicating that sons tends to have education similar to their fathers and daughters tends to have education similar to their mothers.
723

Kukràdjà : territorialidade e estratégias de mobilização social entre os Mẽtyktire (Kayapó) /

Mariano, Michelle Carlesso. January 2019 (has links)
Orientador: Laercio Fidelis Dias / Banca: Antônio Mendes da Costa Braga / Banca: Miriam Cláudia Lourenção Simonetti / Banca: Roque de Barros Laraia / Banca: Mônica Celeida Rabelo Nogueira / Resumo: A presente tese é um estudo etnográfico do grupo Mẽtyktire (Kayapó), na Terra Indígena Capoto/Jarina, aldeia Piaraçú, Norte do estado de Mato Grosso, a partir da categoria vernácula kukràdjà que, etimologicamente, significa algo que leva muito tempo para aprender. Por um lado, o termo é correlacionado com o significado de 'cultura', com aspas, um produto da autoconsciência étnica e um operador nos processos de demanda por direitos. Por outro, significa o "modo de ser", a maneira como os sujeitos veem o mundo a partir de sua cosmologia, um sistema de incorporação significativo dinâmico, como experimentam o vivido enquanto ser/estar no tempo/espaço e como agem para preservar o próprio modo de vida, articulando as mudanças de maneira a reproduzir criativamente a ordem cultural que se atualiza, mantendo a coerência do sistema que o engendra. Parte-se de uma descrição e análise do território, material e simbólico, e dos processos de territorialização entendidos como "modos de estar". Busca-se nas reproduções sociais presentes na ritualística, no cotidiano e no xamanismo, assim como em suas estratégias de mobilização social, elementos para pensar a aparente ambiguidade entre kukràdjà e (meta)cultura enquanto discurso. Os resultados apresentam o kukràdjà como um todo cultural que não se esgota e não se enrijece em processos identitários, visto que é do próprio "modo de ser" apropriar-se de elementos Outros para utilizar em seus próprios termos. / Abstract: The present thesis is an ethnographic study of the Mẽtyktire group (Kayapó), in the Capoto/Jarina Indigenous Territory, Piaraçú village, in the north of the State of Mato Grosso, from the vernacular category kukràdjà which, etymologically, means something that takes a lot of time to learn. On the one hand, the term is correlated with the meaning of 'culture', with quotation marks, a product of ethnic self-consciousness and an operator in the demand for rights processes. On the other hand, it means the "modes of being", the way subjects see the world from their cosmology, a system of significant dynamic incorporation, how they experience the lived as being in time/space and how they act to preserve their own way of life, articulating the changes in a way to creatively reproduce the cultural order that is updated, maintaining the coherence of the system which engenders it. It begins with a description and analysis of the territory, material and symbolic, and the processes of territorialization understood as "modes of being". The social reproductions present in rituals, daily life and shamanism, as well as in their strategies of social mobilization, are used to think the apparent ambiguity between kukràdjà and (meta)culture as a discourse. The results present the kukràdjà as a cultural whole that is not exhaustive and does not become rigid in identity processes, since it is of the own "way of being" to take possession of Other elements to use in its own terms. / Doutor
724

Mobility Optimization for Energy-Efficient 5G Networks : Optimering av Mobilitet för Energieffektiva 5G Nätverk

Gustafsson, Oskar January 2019 (has links)
With the upcoming of the fifth generation of cellular networks there are several perfor- mance requirements that need to be satisfied. This thesis focuses on the topic of mobility which allows users to move through the network using the concept of handovers to switch between base stations. However, the thesis also keeps the energy efficiency in mind and investigates a strategy of reducing the energy consumption. Moving across base stations will inevitably lead to some handover failures, a goal of the system developers is to reduce these, but there exists a tradeoff between too early and too late handover failures. This thesis investigates two approaches of lowering the number of failures by letting the net- work self-optimize parameters in the handover procedure based upon the tradeoff. The first approach includes a parameter adaption to an estimated velocity of the users and the second one making a parameter more granular. Simulating different scenarios in a detailed network simulator shows performance gain by adapting handover parameters to the esti- mated velocity, but gathering more data regarding failures is needed before generalizing the conclusions.
725

Assessing the Impact of Incorporating Residential Histories into the Spatial Analysis of Cancer Risk

Joseph, Anny-Claude 01 January 2019 (has links)
In many spatial epidemiologic studies, investigators use residential location at diagnosis as a surrogate for unknown environmental exposures or as a geographic basis for assigning measured exposures. Inherently, they make assumptions about the timing and location of pertinent exposures which may prove problematic when studying long latency diseases such as cancer. In this work we explored how the association between environmental exposures and disease risk for long-latency health outcomes like cancer is affected by residential mobility. We used simulation studies conditioned on real data to evaluate the extent to which the commonly held assumption of no residential mobility 1) affected the ability of generalized additive models to detect areas of significantly elevated historic environmental exposure and 2) increased bias in the estimates of the relationship between environmental exposures and disease in a case-control study. While the literature suggests that some researchers have begun to develop methods to incorporate historic locations in studies of health outcomes, a number of questions remain. One reason for the knowledge gap is that residential histories have not been collected in most U.S. epidemiologic studies. In our work we evaluated the impact of using public-record database generated histories to estimate the effects of exposure in lieu of using subject-reported addresses collected during a study. Finally, we evaluated the effect of environmental exposure on cancer risk in a case-control study using an approach that combined a multiple membership conditional autoregressive (CAR) model with an environmental exposure index for temporally correlated time-varying exposure assigned based on residential histories. We used this model in a data application to explain bladder cancer risk in the New England Bladder Cancer Study. We included a temporal arsenic exposure index in the model to assess a large number of correlated arsenic exposures.
726

Study of Proteoforms, DNA and Complexes using Trapped Ion Mobility Spectrometry-Mass Spectrometry

Garabedian, Alyssa Lynn 26 March 2018 (has links)
The characterization of biomolecules and biomolecular complexes represents an area of significant research activity because of the link between structure and function. Drug development relies on structural information in order to target certain domains. Many traditional biochemical techniques, however, are limited by their ability to characterize only certain stable forms of a molecule. As a result, multidimensional approaches, such as ion mobility mass spectrometry coupled to mass spectrometry (IMS-MS), are becoming very attractive tools as they provide fast separation, detection and identification of molecules, in addition to providing three-dimensional shape for structural elucidation. The present work expands the use and application of trapped ion mobility spectrometry-coupled to mass spectrometry (TIMS-MS) by analyzing a range of biomolecules (including proteoforms, intrinsically disordered peptides, DNA and molecular complexes). The aim is to i) evaluate the TIMS platform measuring sensitivity, selectivity, and separation of targeted compounds, ii) pioneer new applications of TIMS for a more efficient and higher throughput methodologies for identification and characterization of biomolecular ions, and iii) characterize the dynamics of selected biomolecules for insight into the folding pathways and the intra-or intermolecular interactions that define their conformational space.
727

Exploring the binding of small guest molecules in sodium deoxycholate hydrogels

Seyedalikhani, Mehraveh 03 November 2016 (has links)
Bile salts are supramolecules with amphiphilic properties. Bile salts form aggregates in aqueous solutions. The primary aggregates of bile salts are hydrophobic and the secondary aggregates which form at higher concentrations are relatively hydrophilic. Among bile salts, sodium deoxycholate (NaDC) has been known to form hydrogels at pHs close to the neutral pH and within a certain concentration range. The aim of this work was to provide insight into the properties of a NaDC hydrogel as a supramolecular gel system through three different projects. Pyrene is a hydrophobic polycyclic aromatic compound which was used as a fluorescent probe and the guest for these projects. 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindodicarbocyanine perchlorate (DiD) is another fluorescent compound which was used as another guest. The objective of the first project was to understand the mobility of a small guest molecule in NaDC gel in the presence of cucurbit[6]uril (CB[6]) compound as an additive for the gel. Cucurbit[n]urils are macrocyclic compounds with a hydrophobic cavity and two hydrophilic portals. The presence of CB[6] provides another binding site for pyrene in addition to the primary aggregates of the bile salts. The results showed that the mobility of the guest from water and CB[6] to the bile salts network happens when the temperature is raised. The release of the guest back into the water happens when the gel is cooled. The objective of the second project was to investigate the effect of surfaces with different hydrophilicity on the NaDC gel properties. The results of fluorescence correlation spectroscopy (FCS) experiments revealed that either the hydrophilicity of the surface does not affect the NaDC gel network or the FCS is insensitive to the structural changes induced by the hydrophilicity of the surface. These experiments depicted that the aggregates involved in the gel’s network are the same as those formed in the aqueous solutions. Moreover, results of the steady-state and time-resolved fluorescence experiments showed that the bulk gel properties are not affected by the hydrophilicity of the surface. The objective of the last project was to determine the effect of ions on NaDC gel properties. The results showed that cations with different charge density have different effects on the gel formation and properties. The presence of inorganic salts with a monovalent cation leads to the formation of a kinetically favored gel sample within a few hours after sample preparation. The extension of the network occurs overtime and a thermodynamically stable gel forms a couple of days after sample preparation. / Graduate / 2020-10-20
728

Integration of deformable tire-soil interaction simulation capabilities in physics-based off-road mobility solver

Peterson, Bryan 01 December 2016 (has links)
The objective of this study is to integrate a continuum-based deformable tire and terrain interaction model into a general-use physics-based simulation environment capable of off-road vehicle mobility analysis and high-performance computing potential. Specifically, the physics-based deformable tire and terrain models which were recently proposed and validated by Yamashita, et al. will be implemented into the structure of the multi-physics simulation engine Chrono. In off-road vehicle mobility analysis, empirical and analytical models have been commonly used for vehicle-terrain interaction. While these models utilize experimental data or terramechanics theories to create quick predictive mobility models, they are unable to capture the highly nonlinear behavior of soft soil deformation, which can lead to inaccurate or unreliable results. In order to resolve these limitations, the use of physics-based numerical approaches have been proposed. These methods make use of finite element and discrete element simulations to describe the interaction between the vehicle and deformable terrain. Continuum-based finite element models transfer tire forces to the terrain and model the deformation with elasto-plastic constitutive models. Discrete element soil uses a large number of small rigid body particles to describe the microscale behavior of granular terrain, with the deformation of the soil represented by the motion and contact of the particles. While these physics-based models offer a more accurate vehicle-terrain interaction model, the solution procedure can become complex and computationally expensive since co-simulation techniques are often used. To address these issues, the analysis of physics-based full vehicle dynamics simulations utilizing high-fidelity deformable tire and terrain models in a multi-physics engine with high-performance computing capability is desired. To this end, a continuum mechanics based shear deformable laminated composite shell element proposed by Yamashita, et al. was integrated into the flexible body dynamics simulation framework of Chrono. This element was based on the absolute nodal coordinate formulation and is defined by the global position coordinates and the transverse gradient coordinates of its four nodes. Element lockings are eliminated with the incorporation of the enhanced assumed strain (EAS) and assumed natural strain approaches (ANS). The element formulation includes an extension to model laminated composite materials. Additionally, a locking-free 9-node brick element was integrated into the Chrono framework that makes use of the curvature coordinates at the center of the element. This element is formulated with the Hencky strain measure such that multiplicative finite strain plasticity theory can be used to incorporate soil plasticity models, such as the capped Drucker-Prager failed criterion. With the shear deformable laminated composite shell element and plastic soil brick element integrated into the Chrono multi-physics simulation engine, an off-road deformable tire and terrain interaction model was developed using the vehicle dynamics simulation module Chrono::Vehicle. An off-road deformable tire model was parameterized based on commercial tire properties and generated as an interchangeable tire model option in the full vehicle dynamics system. Benchmark verification tests were performed to ensure the accuracy of tire deformation and tire force characteristics. Further tests were performed to validate a deformable tire model with a deformable tread pattern constructed from shear deformable shell elements and co-rotational tetrahedral elements. The deformable soil model was also integrated as a terrain option in Chrono::Vehicle and numerical tests were carried out to demonstrate its interaction with rigid and deformable tire models. To make use of the computational performance enhancements available in Chrono, Open Multi-Processing (OpenMP) and Advanced Vector Extensions (AVX) were applied to the evaluation of the elastic force/Jacobian matrix and large matrix operations of flexible bodies, respectively, in order to reduce the computation time by nearly 60%.
729

The dehydration of pharmaceutical hydrates under mechanical load

Friedman, Ross Aaron 01 August 2014 (has links)
Nearly one-third of all pharmaceutical substances on the market are able to sorb water into their crystal lattices to form hydrates, which can often compromise stability during processing and/or storage[1]. The tendency of a hydrate to lose its water of crystallization during the manufacturing process of tablet compression is of particular concern to formulation scientists. The amount of water freed as a function of increasing compaction pressure can be explained by the mobility of water within the compact. The mobility of water is determined by the size and shape of the crystal lattice, the numbers and strengths of the hydrogen bonds, and the presence of high-energy sites of disorder[2]. Due to their differing crystal structures, theophylline monohydrate (THM), citric acid monohydrate (CAM), theophylline-water-citric acid cocrystal hydrate (CATHP hydrate), and dicalcium phosphate dihydrate (DCPD) make for interesting model systems to examine the dehydration under mechanical load. The thermal dehydration of both powders and tablets was carried out via thermal gravimetric analysis (TGA). By comparing the temperatures required to start removal of water loss from the powder to that of the tablet, the average amount of water of crystallization that is freed by the compaction process may be quantified. The average amount of water freed by the compaction process results from a competition between the mechanically-induced disorder of the crystal structure that increases the molecular mobility of water within the tablets, and the trapping of water within the interparticulate void spaces at high compaction pressures. The compressibilities, compactabilities, and tabletabilities of the materials were calculated as a function of increasing compaction pressure. The consolidation of the powder bed under pressure was modeled by out-of-die Heckel Analysis which demonstrated the ease of deformation of the model compounds. XRD was utilized to show the decrease in overall order of the crystal lattice as a result of compression as well as anisotropy within the tablets. Crystallographic approaches were utilized to demonstrate the compactness of the crystal structure, and how it affects water mobility. Relaxation pulse experiments (T1, T2) utilizing solid-state NMR were used to directly probe the mobilities of the water molecules within the crystal lattice of THM. The results from T1 and T2 relaxation experiments directly measure the change in molecular mobility of water within the tablets as a function of compaction pressure. This provided independent verification of the trends in molecular mobility and average water freed as a function of compaction pressure observed during TGA dehydration. Raman spectroscopy was used to indirectly measure the polarizability and vibrational motions of THM, and these results corroborate those obtained from ssNMR and TGA dehydration experiments. Overall, this work highlights the potential impact that tablet compression can have on API hydrate stability. 1. Hilfiker R (editor). 2006. Polymorphism in the Pharmaceutical Industry. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co, KGaA. 2. Byrn SR, Pfeiffer RR, Stowell JG. 1999. Solid-state chemistry of drugs. SSCI, Inc.
730

An examination of the educational aspirations parents have for their children

Reed, Eric Jon 01 May 2012 (has links)
I use unique longitudinal data to examine, with greater detail than previously achieved by quantitative researchers, variation in parents' educational aspirations. More specifically, I examine the effects of background characteristics (including demographic, geographic, and socioeconomic origin characteristics), socioeconomic status characteristics, such as education attainment and household income, and social-psychological characteristics, such as locus of control, job-satisfaction, and subjective well-being, on parents' odds of having high educational aspirations for their children (i.e. wanting their children to attain a Graduate or Professional degree).

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