Rank: 298 based on 289 downloads (last 30 days) and 4 files submitted
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Oswaldo Ludwig

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Company/University
KU Leuven

Personal Profile:

Oswaldo Ludwig received the M.Sc. degree in electrical engineering from the Federal University of Bahia, Brazil, in 2004, when he began to teach courses in electrical engineering, such as artificial intelligence, digital control, and digital signal processing. In 2012 he received the PhD degree in electrical engineering from University of Coimbra, where he worked as an assistant professor from 2012 until 2013. Nowadays he is working as a senior researcher at the Department of Computer Science of the KU Leuven. His research interests are in machine learning with application on several fields, such as natural language processing, pedestrian and vehicle detection in the domain of intelligent vehicles, and biomedical data mining.

Professional Interests:
Artificial Intelligence, Machine Learning

 

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Files Posted by Oswaldo View all
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(last 30 days)
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11 Oct 2013 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig neural networks, machine learning, maximummargin princip..., svm, regularization, pattern recognition 56 9
  • 5.0
5.0 | 1 rating
11 Sep 2012 Feature selector based on genetic algorithms and information theory. The algorithm performs the combinatorial optimization by using Genetic Algorithms. Author: Oswaldo Ludwig feature selection, genetic algorithms, artificial intelligen..., information theory, mutual information, pattern recognition 58 7
  • 4.0
4.0 | 5 ratings
17 Mar 2011 HOG descriptor for Matlab Image descriptor based on Histogram of Oriented Gradients for gray-level images Author: Oswaldo Ludwig image descriptor, computer vision, artificial intelligen... 146 20
  • 4.30769
4.3 | 13 ratings
04 Nov 2010 MMGDX: a maximum-margin training method for neural networks Maximum-margin training method applicable to MLP in the context of binary classification. Author: Oswaldo Ludwig neural networks, machine intelligence, machine learning, artificial intelligen..., machine vision 29 1
Comments and Ratings by Oswaldo View all
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05 May 2014 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig

Dear Alweshah,

The best approach is to tune the values of nneu and the punishing parameter C (which can be set in the line 16 of the code) by cross-validation.

28 Oct 2013 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig

Yes, you can download the paper (see Sections 2, 3, and 4): https://www.researchgate.net/publication/256662118_Eigenvalue_decay_a_new_method_for_neural_network_regularization

24 Jan 2013 HOG descriptor for Matlab Image descriptor based on Histogram of Oriented Gradients for gray-level images Author: Oswaldo Ludwig

Could you explain why it was adopted blockwise normalization? From the best of my knowledge, there is no mathematical foundation behind HOG descriptors, only good sense. This is my version, which was made available to be evaluated by the community. Go ahead, you should make the comparison with other algorithms in your case study (Science is not religion, feel free to doubt and inovate).

13 Dec 2012 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig

Mahesh,

Regarding the application of my codes in multi-class problems, the feature selector based on genetic algorithms and information theory can deal with multi-class problem by adopting the target data, y, as a line vector in which each class is represented by a natural number, such as 1 for the first class, 2 for the second... The SVNN can be upgraded to solve multi-class problem by adapting the framework described in "K. Crammer and Y. Singer. On the Algorithmic Implementation of Multi-class SVMs, JMLR, 2001". However, since I finished my PhD, I have no time to work on this research line.

28 Sep 2012 HOG descriptor for Matlab Image descriptor based on Histogram of Oriented Gradients for gray-level images Author: Oswaldo Ludwig

Raul, the number of features depends on the number of cells and histograms bins, see Section II-A of this paper: http://www2.isr.uc.pt/~urbano/PDFs_PUB/Conferencias_Internacionais/2009/[113]2009ITSC09-129-FI.pdf

Comments and Ratings on Oswaldo's Files View all
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08 Jun 2014 Feature selector based on genetic algorithms and information theory. The algorithm performs the combinatorial optimization by using Genetic Algorithms. Author: Oswaldo Ludwig Kaplan, Dmitry

Can you please explain the meaning of the resolucao=15. Why 15?

05 May 2014 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig Ludwig, Oswaldo

Dear Alweshah,

The best approach is to tune the values of nneu and the punishing parameter C (which can be set in the line 16 of the code) by cross-validation.

05 May 2014 Support Vector Neural Network (SVNN) A new training method for MLP neural networks based on the same principles of SVM. Author: Oswaldo Ludwig Alweshah, Mohammed

Dear Dr Ludwig,
Could you help me to know the values of nneu in your code .
SVNN(X,y,nneu)

04 May 2014 HOG descriptor for Matlab Image descriptor based on Histogram of Oriented Gradients for gray-level images Author: Oswaldo Ludwig Sager, Hisham

After taking the HOG of a whole image, and taking the HOG of a 32x32 section, comparing the same location from the whole image HOG and the 32x32 HOG they are not the same. Even in the areas in the middle of the image which are far from the borders.
What is the reason?

31 Mar 2014 HOG descriptor for Matlab Image descriptor based on Histogram of Oriented Gradients for gray-level images Author: Oswaldo Ludwig Gore, Akshay

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