Frederico G. Guimarães

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To explore the ventral medial prefrontal cortex (vMPFC) involvement in behavioral and autonomic fear-conditioned responses to context, vMPFC synaptic transmission was temporarily inhibited by bilateral microinjections of 200 nL of the nonselective synapse blocker CoCl(2) (1 mM). Behavioral activity (freezing, motor activity and rearing) as well as evoked(More)
The Differential Evolution (DE) algorithm was ini­ tially proposed for continuous numerical optimization, but it has been applied with success in many combinatorial optimization problems, particularly permutation-based integer combinatorial problems. In this paper, a new and general approach for combinatorial optimization is proposed using the Differential(More)
We utilize optimization algorithms inspired by the immune system for treating the mixed H2=H1 control problem. Both precisely known systems and uncertain systems with polytopic uncertainties are investigated. For the latter, a novel methodology is proposed to compute the worst case norms within the polytope of matrices. This methodology consists in defining(More)
In this paper, we analyze four dominance criteria in terms of their ability to adequately order sets of points in multiand many-objective optimization problems. The use of relaxed and alternative dominance relationships has been an important tool for improving the performance of multiobjective evolutionary optimization algorithms, and their ordering ability(More)
This paper presents a new operator for genetic algorithms that enhances their convergence in the case of nonlinear problems with nonlinear equality constraints. The proposed operator, named CQA (Constraint Quadratic Approximation), can be interpreted as both a local search engine (that employs quadratic approximations of both objective and constraint(More)
This paper proposes a local search optimizer that, employed as an additional operator in multiobjective evolutionary techniques, can help to find more precise estimates of the Pareto-optimal surface with a smaller cost of function evaluation. The new operator employs quadratic approximations of the objective functions and constraints, which are built using(More)
This paper describes a multiobjective approach for melody harmonization in evolutionary music. There are numerous methods and a myriad of results to a process of harmonization of a given melody. Some implicit rules can be extracted from musical theory, but some harmonic aspects can only be defined by preferences of a composer. Thus, a multiobjective(More)
This paper introduces the concept of Aggregation Trees for the visualization of the results of high-dimensional multi-objective optimization problems, or many-objective problems and as a means of performing dimension reduction. The high dimensionality of manyobjective optimization makes it difficult to represent the relationship between objectives and(More)
In contrast to speech recognition, whose speech features have been extensively explored in the research literature, feature extraction in Sign Language Recognition (SLR) is still a very challenging problem. In this paper we present a methodology for feature extraction in Brazilian Sign Language (BSL, or LIBRAS in Portuguese) that explores the phonological(More)