Parameter Tuning
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. MULTIVARIABLE OPTIMAL CONTROL OF A HEAT EXCHANGER NETWORK WITH BYPASSES
Abstract Heat exchanger networks present an interesting control problem due to coupling among process streams. In this work, the linear quadratic regulator (LQR), a feedback optimal control technique, is used to control stream temperatures on a laboratory scale heat exchanger network, through bypass manipulation, in a multivariable system. The LQR design was
Braz. J. Chem. Eng.. Publicado em: 2016-03
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2. Optimizing the control system of cement milling: process modeling and controller tuning based on loop shaping procedures and process simulations
Based on a dynamical model of the grinding process in closed circuit mills, efficient efforts have been made to optimize PID controllers of cement milling. The process simulation is combined with an autoregressive model of the errors between the actual process values and the computed ones. Long term industrial data have been used to determine the model param
Braz. J. Chem. Eng.. Publicado em: 2014-03
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3. Relationship of lambda and overshoot of step response for a direct synthesis PI controller
The direct synthesis (DS) tuning method is a model-based method for a feedback controller. The main principle of this method is to obtain the controller settings based on a predetermined desired closed loop response. The main advantage is that there is only one parameter to be adjusted, which is lambda (λ), the speed of the desired closed loop response. The
Braz. J. Chem. Eng.. Publicado em: 2012-09
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4. Studying the effect of Building Block Shape on Sierpinski tetrahedron fractal antenna behavior using FDTD-equivalent electric circuits
This research aims to study the effect of the modification in the Building Block Shape (BBS) on the frequency response of Sierpinski three dimensional pre-fractal antenna using conventional circuit analysis. Three different shapes of BBS's are used to build the antenna. The surface current is analyzed and compared for every BBS. A simple model was devised us
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2012-06
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5. Integrating Ridge-type regularization in fuzzy nonlinear regression
In this paper, we deal with the ridge-type estimator for fuzzy nonlinear regression models using fuzzy numbers and Gaussian basis functions. Shrinkage regularization methods are used in linear and nonlinear regression models to yield consistent estimators. Here, we propose a weighted ridge penalty on a fuzzy nonlinear regression model, then select the number
Comput. Appl. Math.. Publicado em: 2012
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6. ComitÃs de Classificadores Baseados nas Redes SOM e Fuzzy ART com Sintonia de ParÃmetros e SeleÃÃo de Atributos via MetaheurÃsticas EvolucionÃrias / Ensembles of classifiers based on SOM and Fuzzy ART networks with parameter tuning and feature selection through evolutionary metaheuristics.
O paradigma de classificaÃÃo baseada em comitÃs tem recebido considerÃvel atenÃÃo na literatura cientÃfica em anos recentes. Neste contexto, redes neurais supervisionadas tÃm sido a escolha mais comum para compor os classificadores base dos comitÃs. Esta dissertaÃÃo tem a intenÃÃo de projetar e avaliar comitÃs de classificadores obtidos atravÃ
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/11/2011
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7. Iterative feedback tuning of uncertain state space systems
Iterative Feedback Tuning is a purely data driven tuning algorithm for optimizing control parameters based on closed loop data. The algorithm is designed to produce an unbiased estimate of the performance cost function gradient for iteratively improving the control parameters to achieve optimal loop performance. This tuning method has been developed for syst
Brazilian Journal of Chemical Engineering. Publicado em: 2010-09
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8. Bioinspired parameter tuning of classifiers / Ajuste de parâmetros de técnicas de classificação por algoritmos bioinspirados
Aprendizado de máquina é uma área de pesquisa na qual se investiga como desenvolver sistemas capazes de aprender com a experiência. Muitos algoritmos de aprendizado possuem parâmetros cujos valores devem ser especificados pelo usuário. Em geral, esses valores influenciam diretamente no processo de aquisição do conhecimento, podendo gerar diferentes m
Publicado em: 2009
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9. Variable selection for survival models based on penalized likelihood / Seleção de covariáveis para modelos de sobrevivência via verossimilhança penalizada
Variable selection is an important step when setting a parsimonious model. However, the most popular variable selection techniques, such as the best subset variable selection and the stepwise method, do not take into account inherent stochastic errors in the variable selection step. This work presents a study of alternative procedures to more popular methods
Publicado em: 2009
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10. Avaliação de técnicas calorimétricas aplicadas ao monitoramento de processos químicos. / Calorimetric technique evaluation applied for chemical processes monitoring.
The increasing demand for the production of polymers with more tight properties has placed great emphasis on the development of accurate and robust online monitoring techniques of polymerization reactions. Unfortunately, most of the main characteristics are not measurable online from analytical methodologies currently available and, therefore, in practice, t
Publicado em: 2009
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11. Comparative study of the performance of fuzzy and conventional controllers applied in a bioprocess / Estudo comparativo do desempenho de controladores fuzzy e convencional aplicados em um bioprocesso
The use of fuzzy controllers in bioprocesses has increased greatly in the last few years. In conventional controllers, assumptions and simplifications are often made to build a precise mathematical model that may be far from the real situation. In contrast, fuzzy controllers are an attractive technique for the control of plants that are ill-defined or non-li
Publicado em: 2007
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12. SPIN AND CORRELATION EFFECTS IN NANOSCOPIC TRANSPORT / EFEITOS DE SPIN E CORRELAÇÃO EM TRANSPORTE NANOSCÓPICO
We investigated spin polarized transport properties through a quantum dot connected with two terminals. An electric current that circulates in our system can have its polarization modulated with an external potential that controls the spin orbit coupling (Rashba effect). We studied the effect of spin polarization n a transistor constituted by a quantum dot w
Publicado em: 2005