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Publications

2015

Maxwell's Equations based 3D model of Light Scattering in the Retina

Authors
Santos, M; Araujo, A; Barbeiro, S; Caramelo, F; Correia, A; Marques, MI; Morgado, M; Pinto, L; Serranho, P; Bernardes, R;

Publication
2015 IEEE 4TH PORTUGUESE MEETING ON BIOENGINEERING (ENBENG)

Abstract
The goal of this work is to develop a computational model of the human retina and simulate light scattering through its structure aiming to shed light on data obtained by optical coherence tomography in human retinas. Currently, light propagation in scattering media is often described by Mie's solution to Maxwell's equations, which only describes the scattering patterns for homogeneous spheres, thus limiting its application for scatterers of more complex shapes. In this work, we propose a discontinuous Galerkin method combined with a low-storage Runge-Kutta method as an accurate and efficient way to numerically solve the time-dependent Maxwell's equations. In this work, we report on the validation of the proposed methodology by comparison with Mie's solution, a mandatory step before further elaborating the numerical scheme towards the propagation of electromagnetic waves through the human retina.

2015

Distributed Vibration Sensing Over 125 km With Enhanced SNR Using Phi-OTDR Over a URFL Cavity

Authors
Martins, HF; Martin Lopez, S; Corredera, P; Diego Ania Castanon, JD; Frazao, O; Gonzalez Herraez, M;

Publication
JOURNAL OF LIGHTWAVE TECHNOLOGY

Abstract
We describe the use of a phase-sensitive optical time domain reflectometer (phi OTDR) over an ultra-long Raman fiber laser cavity allowing fully distributed detection of vibrations over 125 km. Compared to a first-order Raman-assisted phi OTDR, this scheme shows an enhanced signal-to-noise ratio (SNR). This is due to the fact that the relative intensity noise introduced by the Raman amplification is mostly transferred to a lower frequency range, where the balanced detection implemented in the setup provides better suppression of the common-mode noise. The sensor was able to measure vibrations of up to 380 Hz (limit set by the time of flight of light pulses) in a distance of 125 km with a resolution of 10 m and an average SNR of 8 dB with no postprocessing. This implies a > 3 dB improvement in SNR over a first-order Raman-assisted setup with similar characteristics.

2015

Poster Abstract: Real-Time Support in the Proposal for Fine-Grained Parallelism in Ada

Authors
Pinho, LM; Moore, B; Michell, S; Taft, ST;

Publication
2015 IEEE 36TH REAL-TIME SYSTEMS SYMPOSIUM (RTSS 2015)

Abstract
The Ada language has for long provided support for the development of reliable real-time systems, with a model of computation amenable for real-time analysis. To complement the already existent multiprocessor support in the language, an ongoing effort is underway to extend Ada with a fine-grained parallel programming model also suitable for real-time systems. This paper overviews the model which is being proposed, pointing out the main issues still open and road ahead. © 2015 IEEE.

2015

User Modelling in Scheduling System with Artificial Neural Networks

Authors
Cunha, B; Madureira, A; Pereira, JP;

Publication
PROCEEDINGS OF THE 2015 10TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI 2015)

Abstract
User modelling has become a central subject for anybody interested in understanding how users interact with technology. Personalization is a key issue in an era when there is so much information and so many people interacting in so many ways. Modern users desire a customized experience that adapts itself to their requirements and understands what they need even before they notice it. In order to morph any system into an adapting one, every relevant interaction with its users has to be maintained. Then, a mathematical structure capable of discovering patterns amongst that information is necessary, being able to classify users according to the roles they play. With a correct user categorization, the system knows when, how and what to do to adapt its content, via a mixed-initiative approach. In this paper, an artificial neural network is selected as classifier and users are divided in three roles, from beginners to experts. ADSyS, the target system of this proposal, adapts its content based on who is operating it, providing a higher usability. This guide on how to adapt a system to its users is built as part of ADSyS, but is intended to be generalized as a foundation to other systems.

2015

Orientação a objeto: definição, implementação e análise de recursos de teste e validação

Authors
Vincenzi, AMR;

Publication

Abstract

2015

Proceedings of the 6th Workshop on Parallel Programming and Run-Time Management Techniques for Many-core Architectures and the 4th Workshop on Design Tools and Architectures for Multicore Embedded Computing Platforms, PARMA-DITAM 2015, Amsterdam, Netherlands, January 21, 2015

Authors
Agosta, G; Silvano, C; Cardoso, JMP; Hübner, M;

Publication
PARMA-DITAM@HiPEAC

Abstract

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