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J J Lima

Publications and source records attributed to J J Lima.

2 recordsLinked to original sources

X-Ray cardiac angiographic vessel segmentation based on pixel classification using machine learning and region growing

This work proposes a pixel-classification approach for vessel segmentation in x-ray angiograms. The proposal uses textural features such as anisotropic diffusion, features based on the Hessian matrix, mathematical morphology and statistics. These features are extracted from the neighborhood of each pixel. The approach also uses the ELEMENT methodology, which consists of creating a pixel-classification controlled by region-growing where the result of the classification affects further classifications of pixels. The Random Forests classifier is used to predict whether the pixel belongs to the vessel structure. The approach achieved the best accuracy in the literature (95.48%) outperforming unsupervised state-of-the-art approaches.

cs.CV

On Nonlinear Dynamics Of A Nonideal Magnetic System With Shape Memory Alloy To Energy Harvesting Using Uncertainty Exponent And Entropy Of Basin Of Attractions Approaches

In this paper, we dealt the dynamic behavior of a magnetic structure, considering a shape memory spring and a non-ideal motor as excitation. It has fractal behavior of tits basins of attraction, for a set of parameters for energy harvesting. We also considered a set of initial conditions and performed the nonlinear dynamics analysis of the dimensionless mathematical model, and then established their chaotic and periodic regions. We also established the regions of maximum and minimum average power output, which was generated by the vibrations, caused by the considered non-ideal motor.

nlin.CD