Parameter Uncertainties
Mostrando 13-24 de 39 artigos, teses e dissertações.
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13. Rate control system algorithm developed in state space for models with parameter uncertainties
Abstract researching in weightlessness above the atmosphere needs a payload to carry the experiments. To achieve the weightlessness, the payload uses a rate control system (RCS) in order to reduce the centripetal acceleration within the payload. The rate control system normally has actuators that supply a constant force when they are turned on. The developme
J. Aerosp. Technol. Manag.. Publicado em: 2011-12
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14. Model uncertainties of flexible structures vibrations induced by internal flows
In many situations analysts use incomplete models to design a system, or to make decisions. These models are incomplete due to unmodeled phenomena, which means that some features are not included in the model (either because it was not previously thought about or because it would be too expensive to include). These uncertainties related to the model are diff
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-09
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15. Transições de fase hádron-quark em estrelas de nêutrons
Recent advances on the field of high energy physics have enabled the study of matter under extreme conditions and, in this context, new states of matter are being discovered and speculated upon. Among these hypothetical states of matter is the one of deconfined quarks in high densities and/or temperatures. An environment with extreme densities and low temper
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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16. ROBUST VARIABLE STRUCTURE MODEL REFERENCE ADAPTIVE CONTROL APPLIED TO ACTIVE POWER FILTERS / CONTROLE ADAPTATIVO ROBUSTO DE ESTRUTURA VARIÁVEL POR MODELO DE REFERÊNCIA APLICADO A FILTROS ATIVOS DE POTÊNCIA
This works presents a Robust Variable Structure Model Reference Adaptive Control scheme denoted VSRMRAC. In this adaptive control strategy, each parameter of the control law is obtained by the sum of two other adaptive terms. One of them is associated with the RMRAC algorithm, while the other is composed of an adaptive gain rated by an approximated sign func
Publicado em: 2010
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17. Inverse problem in proton-proton elastic scattering in the impact parameter representations / Problema inverso do espalhamento elastico proton-proton na representacao de parametro de impacto
The Impact Parameter and Eikonal Representations are investigated by means of an empirical analysis of the experimental data on proton-proton elastic scattering, at the highest energy region with experimental information available (six data sets at center of mass energies 19.4 - 62.5 GeV). Making use of a novel model-independent parametrization for the scatt
Publicado em: 2009
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18. Control and filtering of time-varying linear systems via parameter dependent Lyapunov functions / Controle e filtragem de sistemas lineares variantes no tempo por meio de funções de Lyapunov dependentes de parametros
The main contribution of this dissertation is to propose conditions for linear filter and controller design, considering both robust and parameter dependent structures, for discrete time-varying systems. The controllers, or filters, are obtained through the solution of optimization problems, formulated in terms of bilinear matrix inequalities, using a method
Publicado em: 2009
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19. Control of dynamic systems : absolute stability, saturation and bilinearity / Controle de sistemas dinamicos : estabilidade absoluta, saturação e bilinearidade
This thesis presents contributions to the solution of the problems of stability analysis and synthesis of state feedback controllers for dynamic systems with non-linear elements, by means of conditions based on linear matrix inequalities and Lyapunov functions. For switched systems subject to saturation in the actuators, convex conditions to design switched
Publicado em: 2009
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20. Filtros de Kalman robustos para sistemas dinâmicos singulares em tempo discreto / Robust Kalman filters for discrete-time singular systems
This thesis considers the optimal robust estimates problem for discrete-time singular dymanic systems. New recursive algorithms are developed for the Kalman filtered and predicted estimated recursions with the corresponding Riccati equations. The singular robust Kalman type filter and the corresponding recursive Riccati equation arer obtained in their most g
Publicado em: 2009
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21. Estimativa de áreas queimadas com produtos modis como subsídio à estimativa de emissões de gases de efeito estufa pela queima de biomassa na Amazônia e Cerrado Brasileiros / Burned area estimation using MODIS fire products as a subsidy for greenhouse gases emissions estimation due biomass burning in the Brazilian Amazon and Cerrado.
At present, the estimates of parameters used in global emissions models are based on low and moderate spatial resolution satellite data, and even though those was an advanced since the rising of the first orbital platforms, it is still necessary to reduce the uncertainty of these estimates. This improvement depends basically, on the capacity of the scientifi
Publicado em: 2009
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22. Timoshenko beam with uncertainty on the boundary conditions
In mechanical system modeling, uncertainties are present and, to improve the predictability of the models, they should be taken into account. This work discusses uncertainties present in boundary conditions using the model of a vibrating Timoshenko beam, free in one end and pinned with rotation constrained by a linear elastic torsional spring in the other en
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2008-12
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23. Radiative transfer model for regular and discontinuous canopies (GRART): application in tree coffee canopies / Modelo de transferência radiativa para dosséis descontínuos regulares (GRART): aplicação para dosséis de café
Regularly displaced discontinuous plant stands such as coffee tree stands, citrus orchards, eucalyptus forests and annual crops at the beginning of their phenological cycle (row structured) are known as highly anisotropic remote sensing targets. Operational parameter estimate upon this kind of remote sensing targets requires a physically-based canopy reflect
Publicado em: 2008
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24. Metodologia para ajuste de historico de produção em campos de petroleo utilizando dados de saturação de perfis / Methodology for production history matching of petroleum fields utilizing logging saturation data
In the production history matching process, the reservoir simulation model is modified in a way that it becomes consistent with production data, keeping the observed restrictions of the geological characterization phase. This technique is limited, mainly in mature fields, when the production history is not reliable, or in the beginning of production, when th
Publicado em: 2008