Dissertations / Theses on the topic 'Multi level linear modelling'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Multi level linear modelling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Cook, Sarah Elizabeth. "Multi level Monte Carlo methods for atmospheric dispersion modelling." Thesis, University of Bath, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616582.
Full textMarioni, Luca. "Modélisation numerique et couplage électromagnétique-CFD dans les procédés decoulée." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM011/document.
Full textMany of the processes used in thesteelmaking industry (e.g. ingot casting,continuous casting, …) can lead todefects: macro-segregation, poormicrostructure properties, surfacedefects. These issues can be solved bycontrolling the temperature and the flowof molten steel. Electromagnetic stirring(EMS) is a widely used technique to steerthe flow of liquid steel by thesuperimposition of an electro-magneticfield. This application is complex becauseit couples several physical problems:multi-phase flow, solidification, heattransfer and low frequency electromagneticinduction. In addition,experimental work is difficult because ofthe size, environment and cost of theconsidered processes. For thesereasons, efficient and effective numericalsimulations are needed to understandEMS applications and improve theaforementioned processes.The objective of this thesis is to developa robust, efficient and accurate numericalprocedure for the multi-physicssimulation of EMS, especially for in-moldstirring in the framework of continuouscasting of steel. This procedure has beenimplemented in the commercial codeTHERCAST® in order to be used forindustrial applications
Carvalho, Vanessa Viana da Silva. "Generation of multi-level and multi-user games through modelling in hierarchical coloured Petri nets." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13488.
Full textThis work presents a method to generate games with multilevel and multiple users using Hierarchical Coloured Petri Nets. The design of a multiuser game containing multiple navigation environments (multilevel) is made from the model of a Hierarchical Coloured Petri Net, in which are specified all of the rules, properties and structures of the game. The created model for the game can be formally analysed, verifying the existence of deadlocks and invalid paths, for example, and others possible conception problems, that can be done with the tools available on CPN Tools. To validate this method, a tool has been developed, called CPN Games, which allows fast and dynamic development of simple conception games only using Hierarchical Coloured Petri Nets. The XML codes of the designed models in CPN Tools are interpreted by CPN Games following a set of predefined rules to instantiate different games, without additional programing. It is demonstrated the mechanisms of the design, analysis and validation of the models and finally it is presented several examples of games developed by this tool.
Este trabalho apresenta um mÃtodo para geraÃÃo de jogos multinÃveis e com mÃltiplos usuÃrios por meio de modelagem em Redes de Petri Coloridas HierÃrquicas. A concepÃÃo de um jogo multiusuÃrio, contendo mÃltiplos ambientes de navegaÃÃo (multinÃveis), à feita a partir da criaÃÃo de um modelo hierÃrquico em Rede de Petri Colorida, no qual se especificam todas as regras, propriedades e estruturas do jogo. O modelo criado para o jogo pode ser analisado formalmente, verificando-se, por exemplo, a existÃncia de bloqueios e de transiÃÃes mortas (caminhos invÃlidos), entre outros possÃveis problemas de concepÃÃo, o que pode ser feito com a utilizaÃÃo de ferramentas disponÃveis no CPN Tools. Para validar esse mÃtodo, foi concebida uma ferramenta, denominada CPN Games, que permite o desenvolvimento rÃpido e dinÃmico de jogos de concepÃÃo simples exclusivamente por Rede de Petri Colorida HierÃrquica. Os cÃdigos em XML de modelos constituÃdos com o CPN Tools sÃo interpretadas pelo CPN Games seguindo um conjunto de regras prà estabelecidas para instanciar diferentes jogos, sem a necessidade de programaÃÃo adicional. SÃo demonstrados os mecanismos de criaÃÃo, anÃlise e validaÃÃo dos modelos e diferentes exemplos de jogos construÃdos com a ferramenta.
Ghorashi, Ali. "Linear decentralised modelling for H Control of a Multi-Axis simulation table." Thesis, University of Bath, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518127.
Full textHarper, John Stuart. "Analytic cache modelling of numerical programs." Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343887.
Full textAnwar, Muslimin. "Modelling exchange rates and monetary policy in emerging Asian economies : non-linear econometric approach." Thesis, Brunel University, 2007. http://bura.brunel.ac.uk/handle/2438/4865.
Full textParks, Kathrin Ann. "A formula for low achievement using multi-level models to understand the impact of individual level effects and school level effects on mathematics achievement /." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969/172.
Full textCatalán, Pallarés Sandra. "Multithreaded Dense Linear Algebra on Asymmetric Multi-core Processors." Doctoral thesis, Universitat Jaume I, 2018. http://hdl.handle.net/10803/461918.
Full textEsta tesis doctoral aborda dos problemas importantes. El primero es el diseño de kernels DLA de bajo nivel para arquitecturas compuestas por dos (o más) tipos de cores. La principal cuestión en este caso es como obtener un distribución de carga computacional balanceada entre los cores heterogéneos mientras se tiene en cuenta que algunos recursos, en particular los niveles de cache, son bien compartidos o privados. La segunda cuestión está parcialmente relacionada con la primera. Concretamente, en la teis se explora un alternativa a los sistemas basados en runtimes para extraer paralelismo sufciente para operaciones DLA complejas mientras se hace un uso eficiente de la jerarquía de cache de la arquitectura. Por tanto, el objetivo general de esta tesis es el estudio, diseño, desarrollo y análsis de soluciones experimentales que son conscientes de la arquitectura para la ejecución de operaciones DLA en arquitecturas de bajo consumo, más concretamente sistemas asimétricos.
Aggidis, Eur Ing George A. "A sequential multi-level generic decision support modelling tool for the development of energy projects." Thesis, Lancaster University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551648.
Full textPatel, Meena. "Numerical study of non-linear spectroscopy and four-wave-mixing in two and multi-level atoms." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2623.
Full textIn this research, we undertake a numerical study of the interaction between laser beams and two as well as multi-level atoms. The main aim of this research is to obtain a deeper understanding of laser-atom interactions and non-linear processes such as optical four-wave mixing. This work will supplement experiments to be conducted by other members of the group, who are involved in generating entangled photons via four-wave mixing in cold rubidium atoms. We begin by performing a basic study of the interaction between laser beams and two-level atoms as an aid to gain knowledge of numerical techniques, as well as an understanding of the physics behind light-atom interactions. We make use of a semi-classical approach to describe the system where the atoms are treated quantum mechanically and the laser beams are treated classically. We study the interaction between atoms and laser beams using the density matrix operator and Maxwell's equations respectively. By solving the optical Bloch equations for two-level atoms we examine the atomic populations and coherences and present plots of the density matrix elements as a function of time. The e ects of various parameters such as laser intensity, detuning and laser modulation have been tested. The behaviour of the laser beam as it propagates through the atomic sample is also studied. This is determined by Maxwell's equation where the atomic polarization is estimated from the coherence terms of the density matrix elements.
French South African Institute of Technology National Research Foundation
Voice, Thomas David. "Stability of congestion control algorithms with multi-path routing and linear stochastic modelling of congestion control." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614022.
Full textHomenauth, Esha. "Evaluating Multi-level Risk Factors for Malaria and Arboviral Infections in Regions of Tanzania." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35633.
Full textRahman, Mohammad Mahbubur. "Microscale modelling of cellular level transport and deformation during food drying." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120676/1/Mohammad%20Mahbubur_Rahman_Thesis.pdf.
Full textHossari, Ghassan, and hossari7@bigpond net au. "A ratio-based multi-level modelling approach for signalling corporate collapse a study of Australian corporations." Swinburne University of Technology. Australian Graduate School of Entrepreneurship, 2006. http://adt.lib.swin.edu.au./public/adt-VSWT20060320.114422.
Full textAhmed, Nuredin Ali Salem. "System level modelling and design of hypergraph based wireless system area networks for multi-computer systems." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2559/.
Full textTran, Giang Thanh. "Developing a multi-level Gaussian process emulator of an Atmospheric General Circulation Model for palaeoclimate modelling." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/412553/.
Full textHernández, Marco Manuel. "A non-linear quasi-3D model for air management modelling in engines." Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/103683.
Full textEngine modelling has become an essential tool in the design of internal combustion engines, allowing considerable reductions in development time and cost. Classical design methodologies are based on prototype manufacturing and trial-and-error tests, but currently, most of those tests have been replaced by numerical computations, so that only the most promising design options are actually tested on engine bench. For years, one-dimensional gas dynamics codes in the time domain have offered sufficiently good solutions for modelling both engine performance and intake and exhaust noise. However, for a more demanding level of design, a 1D representation may not be sufficient to describe accurately the flow in certain elements. This is especially important in the case of silencers. In the case of duct junctions, the existence of complex 3D flow structures is what sets the applicability limit for a simple zero-dimensional description. In view of these limitations, the first option would typically be the use of a computational fluid dynamics (CFD) model; however, the application of such a model to a complete intake or exhaust system entails an excessive computational time. A possible compromise solution is given by quasi-3D models, based on three-dimensional schemes, but with certain simplifications able to significantly reduce the calculation time without excessively affecting the accuracy. Such solutions have become standard in commercial codes and have been successfully applied to silencers with perforated tubes and absorbing material, both in the linear acoustic regime and in real engine conditions, typically non-linear. The objective of this thesis is the development a new quasi-3D numerical method in a staggered-grid, based on the simplification of the momentum equation, to be included in an existing one-dimensional code. Such method however, is not hassle free. In particular, it is affected by the appearance of non-physical oscillations, specially near significant pressure gradients. From the literature review it is determined that this behaviour is typical among second-order schemes and it can be aggravated by the simplifications adopted. After researching the possible solutions to face this problem, three different flux limiters are developed, based on the MDT, FCT and TVD methodologies. In the case of the two latter methods, its effectiveness is well established for finite differences schemes, thus defining a clear improving line for quasi-3D models. Once the numerical method is defined and its stability assured, proper boundary conditions that allow its use must be developed. With this objective, a pressure pulse inlet and an anechoic termination boundary condition are developed, which allow the simulation of an impulse test rig. It should not be forgotten, however, that the ultimate objective is the connection with a one-dimensional code, therefore the compatibility of the quasi-3D numerical method created with the existing one-dimensional methods has to be tested, showing some preliminary results. Eventually, with a fully operative method, the validation process for the applications which it has been mainly developed for, takes place, namely, mufflers and duct junctions modelling. In the case of mufflers, increasingly complex devices are modelled, from constant section geometries to real geometry systems. The results obtained are validated with both linear and non-linear tools. In the case of duct junctions, the main objective is to establish the potential of the new numerical method against the traditional one-dimensional schemes, consequently, results from both approaches are compared to experimental measures, obtaining promising results.
El modelatge s'ha convertit en els últims anys en una eina essencial en el disseny de motors de combustió interna alternatius, ja que permet reduir considerablement el temps i els costos de desenvolupament. Les metodologies de disseny clàssiques es basen en la fabricació de prototips i la realització de proves d'assaig i error. Actualment, la majoria d'aquestes proves han sigut substituïdes per càlculs numèrics, de manera que només les opcions de disseny més prometedores es proven en realitat en banc motor. Durant anys, els codis unidimensionals de dinàmica de gasos en el domini del temps han sigut suficients per a modelar tant les prestacions i el consum del motor com el soroll d'admissió i escapament. No obstant això, per a un nivell més exigent de disseny, una representació 1D pot no ser prou per a descriure amb precisió el flux en certs elements. Açò és especialment important en el cas de silenciadors, on la hipòtesi unidimensional només es pot aplicar a geometries simples. En el cas de les unions de conductes és l'existència d'estructures tridimensionals de flux complexes el que establix el límit de l'aplicabilitat d'una descripció simple zero-dimensional. En vista d'estes limitacions, la primera opció seria típicament l'ús d'un model de dinàmica de fluids computacional (CFD); no obstant això, l'aplicació comporta un temps de càlcul excessiu. Una possible solució de compromís ve donada pels models quasi-3D, basats en esquemes tridimensionals, però amb certes simplificacions capaços de reduir significativament el temps de càlcul sense afectar excessivament la precisió. Tals solucions s'han convertit en estàndard en codis comercials i s'han aplicat amb èxit als silenciadors, tant per a excitacions acústiques en el règim lineal com en condicions reals de motor, típicament no lineals. Aquesta tesi té com a objectiu el desenvolupament d'un nou mètode numèric quasi-3D en una malla escalonada, basat en la simplificació de l'equació de la quantitat de moviment, per a ser inclòs en un codi unidimensional existent. Tal mètode, però, no està lliure d'inconvenients. En particular, es veu afectat per l'aparició d'oscil·lacions no físiques, especialment en gradients de pressió significatius. De la revisió bibliogràfica es determina que aquest comportament és típic en esquemes de segon ordre i es pot veure accentuat per les simplificacions adoptades. Després d'estudiar les possibles solucions aplicables a aquest problema, es desenvolupen tres limitadors de flux diferents, basats en les metodologies MDT, FCT i TVD. En el cas dels dos últims mètodes, la seua efectivitat està ben establida per als esquemes de diferències finites, la qual cosa definix una clara via de millora per als models quasi-3D. Una vegada definit el mètode numèric i assegurada la seua estabilitat, és necessari desenvolupar les condicions de contorn adequades que permeten la seua utilització. Amb aquest objectiu, es desenvolupen les condicions de pols de pressió d'entrada i d'extrem anecoic, els quals permeten simular un banc d'impuls. No cal oblidar que l'objectiu final és la connexió amb un codi unidimensional, per la qual cosa cal comprovar que el mètode numèric cuasi-3D creat és compatible amb els unidimensionals existents, mostrant alguns resultats preliminars. Finalment, es procedix a la seua validació en les aplicacions per a les que ha sigut dissenyat principalment, les quals són, modelatge de silenciadors i unions de conductes. Per al cas dels silenciadors, es modelen dispositius de complexitat creixent, passant per geometries de secció constant fins a sistemes amb geometries reals. Els resultats obtinguts es validen amb altres eines tant lineals com no lineals. En el cas de les unions de conductes, l'objectiu principal és el d'establir el potencial del nou mètode numèric front als unidimensionals tradicionals, per la qual cosa els resultats d'ambdós es comparen amb dades experim
Hernández Marco, M. (2018). A non-linear quasi-3D model for air management modelling in engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/103683
TESIS
Molino, Nicholas Anthony. "A multi-level trade-off methodology for analyzing collaborative system-of-system alternatives." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53585.
Full textNIMNUAL, SOMKID. "APPLICATION OF MULTI-GROUP DIFFUSION THEORY TO MECHANISTIC MODELLING OF LEACHING BEHAVIOR OF SOLIDIFIED LOW-LEVEL RADIOACTIVE WASTE FORMS." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184088.
Full textZhang, Kai. "Multi-level Modelling of Plastic Anisotropy of Aluminium Alloys Using Crystal Plasticity Models and Advanced Yield Functions." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25197.
Full textSfantos, Georgios. "Boundary element methods for cohesive-frictional non linear problems : applications to wear, contact and multi-scale damage modelling." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439265.
Full textFisco, Stefano. "Modelling of decentral DHW preparation in large multi-family buildings." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18295/.
Full textHope, Elizabeth Jane. "Modelling the farm level effects of set-aside payments and quotas in the UK cereal sector : a linear programming analysis." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481464.
Full textWigelsworth, Michael Robert. "A multi-level approach to assessing the impact of Social and Emotional Learning : Secondary SEAL." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/a-multilevel-approach-to-assessing-the-impact-of-social-and-emotional-learning-secondary-seal(5810bffa-e877-4903-9cc0-0da55a31942a).html.
Full textvan, Lint J. W. C., and S. C. Calvert. "A generic multi-level framework for microscopic traffic simulation—Theory and an example case in modelling driver distraction." Elsevier, 2018. https://publish.fid-move.qucosa.de/id/qucosa%3A72789.
Full textLouati, Dorra. "Couplage de modèles multi-niveau de systèmes complexes : application aux systèmes biologiques." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066630/document.
Full textThe objective of this thesis is to propose an approach for coupling metabolic and ecological levels in a complex biological system. This approach is presented as formal model describing the organism metabolism , which, thanks to DEVS formalism (Discrete Event System Specification), allows a coupling with models of interaction between organisms and between organisms and their environment. A study of the different modeling paradigms allowed us to identify, on the one hand the appropriate paradigm for each level and on the other hand the coupling factors formed by the variables at the interface of individual's internal and external worlds. This coupling explores the effect of lower-level dynamics on the emergence of higher-level characteristics. Two multiagent models, the first on sexual allocation and the second on optimal foraging, concretize the physiology/ecology coupling and show that this coupling makes it possible to connect the individual's internal world with its external world. The strong coupling, in the sense of model integration, explored in a first phase, was improved by the proposal of a formal model, called DEB-DEVS, of the metabolic model (of the Dynamic Energy Budget Theory (DEB)) common to the previous models. This proposal is the result of a reflection on the representation of internal dynamics of agents in ecological models. DEB-DEVS has been illustrated by two classical models of theoretical ecology
Ledolter, Johannes. "Multi-Unit Longitudinal Models with Random Coefficients and Patterned Correlation Structure: Modelling Issues." Department of Statistics and Mathematics, WU Vienna University of Economics and Business, 1999. http://epub.wu.ac.at/432/1/document.pdf.
Full textSeries: Forschungsberichte / Institut für Statistik
Meshack, Enock Obuba. "The Role of School and Motivational Factors in Mathematics Achievement and Self-efficacy: A Multi-level Analysis." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1376065887.
Full textSchafer, Ingo. "Orthogonal and Nonorthogonal Expansions for Multi-Level Logic Synthesis for Nearly Linear Functions and their Application to Field Programmable Gate Array Mapping." PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/1339.
Full textTurnes, Christopher Kowalczyk. "Efficient solutions to Toeplitz-structured linear systems for signal processing." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51878.
Full textCeranic, Boris. "Optimum design of reinforced concrete skeletal systems using non-linear programming techniques." Thesis, University of Derby, 2000. http://hdl.handle.net/10545/583616.
Full textZhu, Xiaoting [Verfasser]. "Simulation of Sea Level Variations in The Tropical Pacific Using A Linear Multi-mode Model with Application to The Emergence of Central Pacific ENSO / Xiaoting Zhu." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1160235422/34.
Full textBörgens, Eva Susanne Ilona [Verfasser], Florian [Akademischer Betreuer] Seitz, Nico [Gutachter] Sneeuw, Per [Gutachter] Knudsen, and Florian [Gutachter] Seitz. "Water Level Modelling of the Mekong River Based on Multi-Mission Altimetry / Eva Susanne Ilona Börgens ; Gutachter: Nico Sneeuw, Per Knudsen, Florian Seitz ; Betreuer: Florian Seitz." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/116631510X/34.
Full textCarpenter, Lewis. "Long-term progression of structural joint damage in early rheumatoid arthritis." Thesis, University of Hertfordshire, 2017. http://hdl.handle.net/2299/18353.
Full textShang, Lei, and lei shang@ieee org. "Modelling of Mobile Fading Channels with Fading Mitigation Techniques." RMIT University. Electrical and Computer Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20061222.113303.
Full textOng, Yongzhi [Verfasser], Winfried [Akademischer Betreuer] Kurth, and Hans-Jörg [Akademischer Betreuer] Kreowski. "Extension of the Rule-Based Programming Language XL by Concepts for Multi-Scaled Modelling and Level-of-Detail Visualization / Yongzhi Ong. Gutachter: Winfried Kurth ; Hans-Jörg Kreowski. Betreuer: Winfried Kurth." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1070423653/34.
Full textThorén, Daniel. "Radar based tank level measurement using machine learning : Agricultural machines." Thesis, Linköpings universitet, Programvara och system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176259.
Full textHe, Qing. "Robust-Intelligent Traffic Signal Control within a Vehicle-to-Infrastructure and Vehicle-to-Vehicle Communication Environment." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/196011.
Full textMartín-Sacristán, Gandía David. "3GPP Long Term Evolution: Performance Analysis and Evolution towards 4G with Coordinated Multi-Point Transmission." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/63261.
Full text[ES] En la actual sociedad, hay una creciente necesidad de acceso a servicios de comunicación de datos de forma ubicua, móvil y a velocidades cada vez más altas. Esta demanda ha motivado el desarrollo de la cuarta generación de comunicaciones móviles (4G) y su evolución hacia la quinta generación (5G). Este desarrollo ha requerido una revolución en la interfaz radio de los sistemas de comunicaciones móviles modificando en gran medida sus capacidades y la forma en la que se gestionan sus recursos. Este es el caso de la tecnología conocida como Long Term Evolution (LTE) y su versión 4G llamada LTE-Advanced. En concreto, esta Tesis Doctoral aborda el modelado, análisis de la gestión de recursos radio y evaluación de prestaciones del enlace descendente de LTE y LTE-Advanced, donde, de entre las características de LTE-Advanced, se ha puesto el foco de atención en la transmisión multipunto coordinada (CoMP). La Tesis proporciona una descripción detallada de las principales características de LTE y LTE-Advanced. La gran complejidad del sistema descrito ha motivado que la metodología de estudio haya sido la simulación mediante ordenador. La Tesis realiza una descripción detallada de dicha metodología y del modelado del sistema empleado, incluyendo algunas aportaciones del autor en este campo. De entre éstas, destaca la provisión de resultados de simulación de nivel de enlace que se usaron en el proyecto europeo WINNER+ para la evaluación de LTE. En cuanto al análisis de la gestión de recursos radio en LTE, en primer lugar, se explican los fundamentos de la adaptación al enlace y el scheduling. En relación con el scheduling, se realiza un estudio del concepto de proportional fairness y de la implementación subóptima típicamente usada en LTE para maximizar esta métrica. Este estudio ha dado como resultado una modificación de la implementación típica que ha demostrado ser capaz de aumentar la proportional fairness en la asignación de recursos con un bajo incremento de complejidad. Además, el análisis de la adaptación al enlace ha revelado el problema del efecto de "luz de flash" consistente en la alta variabilidad de la interferencia debida a rápidos cambios en las decisiones del scheduler. La Tesis demuestra que se pueden mejorar las prestaciones del sistema estabilizando dichas decisiones mediante una implementación concreta. El bloque de análisis de la gestión de recursos se completa con el estudio de CoMP. Específicamente, se estudia una solución con coordinación de scheduling y conformación de haz (CS/CB) que tiene en cuenta suposiciones reales y robustas en cuanto al conocimiento que los puntos coordinados tienen de los canales radio. La Tesis propone esta solución por su sencillez y capacidad de mejorar la eficiencia de los sistemas de comunicaciones móviles, tanto en cobertura de velocidades altas de transmisión como en capacidad, aun teniendo un conocimiento incompleto del canal. En cuanto a la evaluación de LTE y LTE-Advanced, ésta se realiza en dos tipos de escenarios. Por un lado, los escenarios definidos en el proceso de evaluación de IMT-Advanced. En este marco, se evalúa la importancia de diferentes técnicas de transmisión multiantena, incluyendo CoMP, y considerando tráfico de tipo full-buffer. Se ha obtenido una gran mejora de prestaciones por la multiplexación espacial de usuarios y mejoras discretas por el uso de CoMP. El segundo grupo de escenarios son los definidos por el proyecto europeo METIS para evaluación de tecnologías 5G, concretamente se han elegido un escenario de interiores con una oficina, y uno de exteriores con un estadio deportivo. En estos escenarios se utiliza un tráfico realista y se ha demostrado la utilidad de CoMP para mejorar las prestaciones del sistema. En estos escenarios con despliegues menos uniformes, o con un número limitado de transmisores provocando la mayor parte de la interferencia, es donde esta Tesis ha encontrado la mayor u
[CAT] En l'actual societat de la informació, hi ha una creixent necessitat d'accés a serveis de comunicació de dades de forma ubiqua, mòbil i a velocitats cada vegada més altes. Aquesta demanda de la societat, ha motivat el desenrotllament de la quarta generació de comunicacions mòbils (4G) i la seua evolució cap a la quinta generació (5G). Aquest desenrotllament ha requerit una revolució en la interfície ràdio dels sistemes de comunicacions mòbils i ha modificat en gran manera les seues capacitats i la forma en què es gestionen els seus recursos. Aquest és el cas de la tecnologia coneguda com a Long Term Evolution (LTE) i la seua versió 4G anomenada LTE-Advanced. En concret, aquesta Tesi Doctoral aborda el modelatge, anàlisi de la gestió de recursos ràdio i avaluació de prestacions de l'enllaç descendent de LTE i LTE-Advanced, on, d'entre les característiques de LTE-Advanced, s'ha posat el centre d'atenció en la transmissió multipunt coordinada (CoMP). La Tesi proporciona una descripció detallada de les principals característiques de LTE i LTE-Advanced. La gran complexitat del sistema descrit ha motivat que la metodologia d'estudi s'haja basat en simulació per mitjà d'ordinador. La Tesi realitza una descripció detallada de la metodologia de simulació i del modelatge del sistema empleat, incloent-hi algunes aportacions de l'autor en aquest camp. D'entre aquestes, destaca la provisió de resultats de simulació de nivell d'enllaç que es van usar en el projecte europeu WINNER+ per a l'avaluació de LTE. Pel que fa a l'anàlisi de la gestió de recursos ràdio en LTE, en primer lloc, s'expliquen els fonaments de l'adaptació a l'enllaç i el scheduling. En relació amb el scheduling, es realitza un estudi del concepte de proportional fairness i de la implementació subòptima típicament usada en LTE per a maximitzar aquesta mètrica. L'estudi ha donat com a resultat una modificació de la implementació típica que ha demostrat ser capaç d'augmentar la proportional fairness en l'assignació de recursos amb un baix increment de complexitat. A més, l'anàlisi de l'adaptació a l'enllaç ha desvetllat el problema de l'efecte de "llum de flaix" consistent en la alta variabilitat de la interferència deguda a una ràpida variació de les assignacions de recursos. La Tesi demostra que es poden millorar les prestacions del sistema estabilitzant les decisions del scheduler mitjançant una implementació concreta. En el bloc d'anàlisi de la gestió de recursos d'aquesta Tesi es completa amb l'estudi de CoMP. Específicament, s'estudia una solució amb coordinació de scheduling i conformació de feix (CS/CB), que té en compte suposicions reals i robustes quant al coneixement que els punts coordinats tenen dels canals ràdio dels usuaris servits. La Tesi proposa aquesta solució per la seua senzillesa i capacitat de millorar l'eficiència dels sistemes de comunicacions mòbils, tant en cobertura de velocitats altes de transmissió com en capacitat, encara tenint un coneixement incomplet del canal. Quant a l'avaluació de LTE i LTE-Advanced, aquesta es realitza en dos tipus d'escenaris diferents. D'una banda, els escenaris definits dins del procés d'avaluació de tecnologies IMT-Advanced. Dins d'aquest marc, s'avalua la importància de diferents tècniques de transmissió multi-antena, incloent-hi CoMP, i considerant tràfic de tipus full-buffer. S'ha obtingut una gran millora de prestacions amb la multiplexació espacial d'usuaris i una discreta millora amb CoMP. El segon grup d'escenaris són els definits pel projecte europeu METIS per a l'avaluació de tecnologies 5G, concretament s'han triat un escenari d'interiors amb una oficina, i un d'exteriors amb un estadi esportiu, on s'ha utilitzat un tràfic realista. En aquests escenaris amb desplegaments menys uniformes, o amb un nombre limitat de transmissors provocant la major part de la interferència, és on aquesta Tesi ha trobat la utilitat més gran de
Martín-Sacristán Gandía, D. (2016). 3GPP Long Term Evolution: Performance Analysis and Evolution towards 4G with Coordinated Multi-Point Transmission [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63261
TESIS
Abu-Shikhah, Nazih M. "New methods in speech enhancement, and modelling, with applications to low bit rate speech coding." Thesis, Queensland University of Technology, 2001.
Find full textAugusto, Rosângela Aparecida. "Avaliação da efetividade de programa governamental de distribuição de leite fortificado no crescimento de crianças de 6 a 24 meses de famílias de baixa renda, residentes no interior do Estado de São Paulo." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/89/89131/tde-23112009-145933/.
Full textOBJECTIVE: To assess the effectiveness of a state-run food supplementation program for child growth according to childrens nutritional status at enrollment. METHODS: Cohort study including secondary data of 25,433 low-income children aged between 6 and 24 months enrolled in a fortified milk program \"Projeto Vivaleite\" in 311 cities in the State of São Paulo, Brazil, between 2003 and 2008. Children\'s growth was assessed based on weight-for-age (WA) z-scores, estimated following WHO criteria (2006). Data was routinely collected at the program enrollment and every 4 months. Inclusion criteria were: being 6 to 24 months of age at enrollment; having at least two weight measures including the first measure at enrollment; and not having any ill health conditions. At enrollment, children were categorized into three groups based on their z-scores: no compromised weight gain (z> 1); at risk of low weight (-2 ≤z< -1), and low weight (z< -2). Multilevel linear regression analysis (mixed model) was performed for comparison, considering age, of adjusted average z-scores between new children enrolled and those in the program for at least four months, adjusted for correlation between repeat measures. RESULTS: The program had a positive effect on children\'s weight gain. Based on their nutritional status at enrollment, adjusted average weight gain z-score was 0,1827 in children with compromised weight gain, 0,5659 in those at risk of low weight, and 1,0049 in those with low weight. CONCLUSIONS: The milk program is effective for child growth, as measured by WA z-scores. The most pronounced effect was seen among children who showed less favorable levels of weight at enrollment.
Maczka, Melissa May. "Investigations into the effects of neuromodulations on the BOLD-fMRI signal." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:96d46d4d-480b-48d7-9f2d-060e76c5f8aa.
Full textMickelson, Bryan K. "Client Change in Multi-Model Treatment: A Comparison of Change Trajectories in Group, Individual, and Conjoint Formats in a Counseling Center." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2758.pdf.
Full textSouza, Valeska Martins de. "PROJETO DE CONTROLADOR ROBUSTO VIA OTIMIZAÇÃO CONVEXA." Universidade Federal do Maranhão, 2002. http://tedebc.ufma.br:8080/jspui/handle/tede/319.
Full textIn this dissertation a new methodology of based convex optimization in linear matrix inaqualities is proposal as basic instrument for the synthesis of robust controllers of discrete and linear dynamic systems that take care of to the specifications of perturbations of worse case.
Nesta dissertação é proposta uma nova metodologia de otimização convexa baseada em desigualdades matriciais lineares como instrumento básico para a síntese de controladores robustos de sistemas dinâmicos discretos e lineares que atendam às especificações de pertubações de pior caso.
Denimal, Enora. "Prédiction des instabilités de frottement par méta-modélisation et approches fréquentielles : Application au crissement de frein automobile." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC039/document.
Full textBrake squeal is a noise nuisance that represents significant costs for the automotive industry. It originates from complex phenomena at the frictional interface between the brake pads and the disc. The stability analysis remains the preferred method in the industry today to predict the stability of a brake system despite its over- and under-predictive aspects.In order to build a robust brake system, it is necessary to find the technology that limits instabilities despite some uncertain parameters present in the system. Thus, one of the main objectives of the PhD thesis is to develop a method to treat and propagate the uncertainty and variability of some parameters in the finite element brake model with reasonable numerical costs.First, the influence of a first group of parameters corresponding to contacts within the system was studied in order to better understand the physical phenomena involved and their impacts on the squealing phenomenon. An approach based on the use of a genetic algorithm has also been implemented to identify the most unfavourable set of parameters in terms of squeal propensity on the brake system.In a second step, different meta-modelling methods were proposed to predict the stability of the brake system with respect to different parameters that may be design parameters or uncertain parameters related to the environment of the brake system.In a third step, a non-linear analysis method complementary to the stability analysis was proposed and developed. It is based on the tracking of the stability of an approximate vibrational solution and allows the identification of unstable modes present in the dynamic response of the system. This method was applied to a simple academic model before demonstrating its feasibility on the complete industrial brake finite element model under study
Nassiri, Esmail. "Modelling nonlinear behaviour of two-dimensional steel structures subjected to cyclic loading." Thesis, Queensland University of Technology, 1998.
Find full textAmate, Ahmed Mohammed. "Device-device communication and multihop transmission for future cellular networks." Thesis, University of Hertfordshire, 2015. http://hdl.handle.net/2299/16309.
Full textBella, Malika. "Développement d'une approche multi-échelle de modélisation de dispositifs thermoélectriques : application à des systèmes de capteurs sans fils autonomes sur le corps humain." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4755.
Full textThermoelectric devices, capitalizing on waste heat conversion, offer good prospects for the development of autonomous systems. The main challenges for technology development are to obtain flexible, environmentally friendly and low-cost thermoelectric devices with performances sufficient enough to power small electronic devices. The aim of this thesis was thus to propose a methodology for the global analysis of thermoelectric devices for ambient temperature applications. The developed methodology enables the evaluation of key parameters impact on the global system. First, a multiscale approach for thermoelectric devices modelling is developed. In this scope, three parallel levels of modeling are addressed. At the system level, a compact model is developed in order to evaluate overall system efficiency as a function of the thermal environment. At the device level, virtual prototypes of printed devices are built and their performances are evaluated via a finite-element simulation tool. Low temperature gradient has to be dealt with by appropriate architecture design. At the material level, quantum DFT is used in conjunction with semi-classical approach using Boltzmann transport theory to calculate electronic properties. Tetrahedrite and famatinite compounds are chosen due to their promising thermoelectric properties at room temperature and their relative abundance and low cost. Secondly, an experimental work has been conducted on the synthesis of sulphide nanoparticles. Quasi-monodisperse nanoparticles with a size not exceeding 50 nm have successfully been fabricated via a low cost and easily scalable surfactant assisted solvothermal technique
Mkadara, Geneviève. "Contribution à la surveillance des pompes hydrauliques à pistons axiaux pour les hélicoptères, avec un accent particulier sur la modélisation à paramètres localisés." Thesis, Toulouse, INSA, 2020. http://www.theses.fr/2020ISAT0020.
Full textThis dissertation presents a contribution to helicopter axial piston pump monitoring through modelling and simulation. A lumped-parameter model of such pump is developed to serve as a virtual test bench for monitoring studies. As lumped-parameter models of axial piston pumps are less detailed than distributed-parameter models, the author proposes improvements of lumped-parameter modelling state-of-the-art, focusing on the monitoring industrial need. The proposal concentrates on the pressure compensator simulation in degraded conditions, and on the slipper/swashplate leakage computation through a variable gap height. The developed pump model is compared to experimental data. Then, a graphical tool is proposed, (the Damage Identification Curve, DIC), which allows for the isolation of pump degradation within the hydraulic system using discharge and case drain pressure steady-state measurements. The study is concluded by recommendations for increasing the maturity level of the proposed monitoring approach
Giovannone, Carrie Lynn. "A Longitudinal Study of School Practices and Students’ Characteristics that Influence Students' Mathematics and Reading Performance of Arizona Charter Middle Schools." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1288808181.
Full text