Visible to the public Biblio

Filters: Author is Santos, A.  [Clear All Filters]
2017-03-08
Gómez-Valverde, J. J., Ortuño, J. E., Guerra, P., Hermann, B., Zabihian, B., Rubio-Guivernau, J. L., Santos, A., Drexler, W., Ledesma-Carbayo, M. J..  2015.  Evaluation of speckle reduction with denoising filtering in optical coherence tomography for dermatology. 2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI). :494–497.

Optical Coherence Tomography (OCT) has shown a great potential as a complementary imaging tool in the diagnosis of skin diseases. Speckle noise is the most prominent artifact present in OCT images and could limit the interpretation and detection capabilities. In this work we evaluate various denoising filters with high edge-preserving potential for the reduction of speckle noise in 256 dermatological OCT B-scans. Our results show that the Enhanced Sigma Filter and the Block Matching 3-D (BM3D) as 2D denoising filters and the Wavelet Multiframe algorithm considering adjacent B-scans achieved the best results in terms of the enhancement quality metrics used. Our results suggest that a combination of 2D filtering followed by a wavelet based compounding algorithm may significantly reduce speckle, increasing signal-to-noise and contrast-to-noise ratios, without the need of extra acquisitions of the same frame.

2015-05-01
Arieta, F., Barabasz, L.T., Santos, A., Nogueira, M..  2014.  Mitigating Flooding Attacks on Mobility in Infrastructure-Based Vehicular Networks. Latin America Transactions, IEEE (Revista IEEE America Latina). 12:475-483.

Infrastructure-based Vehicular Networks can be applied in different social contexts, such as health care, transportation and entertainment. They can easily take advantage of the benefices provided by wireless mesh networks (WMNs) to mobility, since WMNs essentially support technological convergence and resilience, required for the effective operation of services and applications. However, infrastructure-based vehicular networks are prone to attacks such as ARP packets flooding that compromise mobility management and users' network access. Hence, this work proposes MIRF, a secure mobility scheme based on reputation and filtering to mitigate flooding attacks on mobility management. The efficiency of the MIRF scheme has been evaluated by simulations considering urban scenarios with and without attacks. Analyses show that it significantly improves the packet delivery ratio in scenarios with attacks, mitigating their intentional negative effects, as the reduction of malicious ARP requests. Furthermore, improvements have been observed in the number of handoffs on scenarios under attacks, being faster than scenarios without the scheme.