Rafael Krummenauer

Dr. Rafael Krummenauer

Universidade Estadual de Maringá, Maringá, Paraná, Brazil
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2012 in Signal Processing
Verified
Journal Article
Closed access
LBLevy Boccato
Levy Boccato
RKRafael Krummenauer
Rafael Krummenauer
RARomis Attux
Romis Attux
ALAmauri Lopes
Amauri Lopes

30 October 2015 in Geophysics
Verified
Journal Article
Closed access
TBTiago Barros
Tiago Barros
RFRafael Ferrari
Rafael Ferrari
RKRafael Krummenauer
Rafael Krummenauer
RLRenato da Rocha Lopes
Renato da Rocha Lopes
The common-reflection surface (CRS) method is a sophisticated alternative to the traditional common-midpoint stacking because its traveltime approximation allows for the use of more traces than the normal moveout. This in turn requires more parameters for the moveout description, thus increasing the computational burden of the parameter estimation. In the literature, a suboptimal strategy is often used, which decreases the complexity but, as we found in this work, compromises the accuracy of the parameters in some cases. To cope with this problem, in this work, we have devised detailed information for efficient estimation of the CRS parameters using the differential evolution (DE) global optimization algorithm. Because we used data sets with low fold and low signal-to-noise ratio, from which no reliable velocity analysis could be easily performed, we applied this algorithm in a fully automatic global search, i.e., without any velocity guide. The results for a 2D real data set from Brazil indicated that the global strategy yielded good results, both in terms of image quality as in the quality of the parameter volumes, especially the stacking velocity estimates, while keeping the computational costs relatively low. We also developed a convergence and a sensitivity analysis of the DE that shows its computational efficiency and the robustness of the optimization method with respect to the choice of the control parameters of the algorithm.

1 May 2010 in Signal Processing
Verified
Journal Article
Closed access
RKRafael Krummenauer
Rafael Krummenauer
MCM. Cazarotto
M. Cazarotto
ALA. Lopes
A. Lopes
PLP. Larzabal
P. Larzabal
PFP. Forster
P. Forster

28 March 2013 in Circuits, Systems, and Signal Processing
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Journal Article
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PDF file
RKRafael Krummenauer
Rafael Krummenauer
RFRafael Ferrari
Rafael Ferrari
RSRicardo Suyama
Ricardo Suyama
RARomis Attux
Romis Attux
CJCynthia Junqueira
Cynthia Junqueira
ALAmauri Lopes
Amauri Lopes

9 October 2023 in Agriengineering
Verified
Journal Article
Open access
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MGMatheus Gremes
Matheus Gremes
IFIgor Rossi Fermo
Igor Rossi Fermo
RKRafael Krummenauer
Rafael Krummenauer
FFFranklin César Flores
Franklin César Flores
CACid Marcos Gonçalves Andrade
Cid Marcos Gonçalves Andrade
OLOswaldo Curty da Motta Lima
Oswaldo Curty da Motta Lima
Agriculture is one of the most essential activities for humanity. Systems capable of automatically harvesting a crop using robots or performing a reasonable production estimate can reduce costs and increase production efficiency. With the advancement of computer vision, image processing methods are becoming increasingly viable in solving agricultural problems. Thus, this work aims to count green oranges directly from trees through video footage filmed in line along a row of orange trees on a plantation. For the video image processing flow, a solution was proposed integrating the YOLOv4 network with object-tracking algorithms. In order to compare the performance of the counting algorithm using the YOLOv4 network, an optimal object detector was simulated in which frame-by-frame corrected detections were used in which all oranges in all video frames were detected, and there were no erroneous detections. Being the scientific and technological innovation the possibility of distinguishing the green color of the fruits from the green color of the leaves. The use of YOLOv4 together with object detectors managed to reduce the number of double counting errors and obtained a count close to the actual number of oranges visible in the video. The results were promising, with an mAP50 of 80.16%, mAP50:95 of 53.83%, precision of 0.92, recall of 0.93, F1-score of 0.93, and average IoU of 82.08%. Additionally, the counting algorithm successfully identified and counted 204 oranges, closely approaching the actual count of 208. The study also resulted in a database with an amount of 644 images containing 43,109 orange annotations that can be used in future works.

25 August 2023 in Inventions
Verified
Journal Article
Open access
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LPLucas Lima Provensi
Lucas Lima Provensi
RSRenata Mariane de Souza
Renata Mariane de Souza
GGGabriel Henrique Grala
Gabriel Henrique Grala
RBRosângela Bergamasco
Rosângela Bergamasco
RKRafael Krummenauer
Rafael Krummenauer
CACid Marcos Gonçalves Andrade
Cid Marcos Gonçalves Andrade
This research aims to employ and qualify the bio-inspired algorithms: Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Differential Evolution Algorithm (DE) in the extraction of the parameters of the circuit equivalent to a photovoltaic module in the models of a diode and five parameters (1D5P) and two diodes and seven parameters (2D7P) in order to simulate the I-V characteristics curves for any irradiation and temperature scenarios. The peculiarity of this study stands in the exclusive use of information present in the module’s datasheet to carry out the full extraction and simulation process without depending on external sources of data or experimental data. To validate the methods, a comparison was made between the data obtained by the simulations with data from the module manufacturer in different scenarios of irradiation and temperature. The algorithm bound to the model with the highest accuracy was DE 1D5P, with a maximum relative error of 0.4% in conditions close to the reference and 3.61% for scenarios far from the reference. On the other hand, the algorithm that obtained the worst result in extracting parameters was the GA in the 2D7P model, which presented a maximum relative error of 9.59% in conditions far from the reference.