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Publicações

2013

Differential Evolutionary Particle Swarm Optimization (DEEPSO): a successful hybrid

Autores
Miranda, V; Alves, R;

Publicação
2013 1ST BRICS COUNTRIES CONGRESS ON COMPUTATIONAL INTELLIGENCE AND 11TH BRAZILIAN CONGRESS ON COMPUTATIONAL INTELLIGENCE (BRICS-CCI & CBIC)

Abstract
This paper explores, with numerical case studies, the performance of an optimization algorithm that is a variant of EPSO, the Evolutionary Particle Swarm Optimization method. EPSO is already a hybrid approach that may be seen as a PSO with self-adaptive weights or an Evolutionary Programming approach with a self-adaptive recombination operator. The new hybrid DEEPSO retains the self-adaptive properties of EPSO but borrows the concept of rough gradient from Differential Evolution algorithms. The performance of DEEPSO is compared to a well-performing EPSO algorithm in the optimization of problems of the fixed cost type, showing consistently better results in the cases presented.

2013

Optical inclinometer based on phase-shifted Bragg grating in a taper configuration

Autores
Moura, JPP; Silva, SO; Becker, M; Rothardt, M; Bartelt, H; Frazao, O;

Publicação
FIFTH EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS

Abstract
A simple optical inclinometer based on phase-shifted Bragg grating in a taper configuration is proposed. The phase-shifted FBG was fabricated using a DUV femtosecond laser technique in the taper region. The sensing head was characterized for different angle curvatures and also to strain. The angle and strain sensitivities of the inclinometer are 13.15 pm/degree and 8.96 pm/mu epsilon.

2013

Numerical study on spectral domain optical coherence tomography spectral calibration and re-sampling importance

Autores
Hosseiny, H; Carmelo Rosa, C;

Publicação
Photonic Sensors

Abstract
A spectral calibration technique, a data processing method and the importance of calibration and re-sampling methods for the spectral domain optical coherence tomography system were numerically studied, targeted to optical coherence tomography (OCT) signal processing implementation under graphics processing unit (GPU) architecture. Accurately, assigning the wavelength to each pixel of the detector is of paramount importance to obtain high quality images and increase signal to noise ratio (SNR). High quality imaging can be achieved by proper calibration methods, here performed by phase calibration and interpolation. SNR was assessed employing two approaches, single spectrum moving window averaging and consecutive spectra data averaging, to investigate the optimized method and factor for background noise reduction. It was demonstrated that the consecutive spectra averaging had better SNR performance. © 2012 The Author(s).

2013

Next generation of Fabry-Perot sensors for high-temperature

Autores
Ferreira, MS; Roriz, P; Silva, SO; Santos, JL; Frazao, O;

Publicação
OPTICAL FIBER TECHNOLOGY

Abstract
This paper presents an overview of optical fiber sensors based on Fabry-Perot interferometers with a focus on high temperature applications. The next generation of these fiber types interferometers are based in photonic crystal fibers, microfabrication as well as by chemical etching of special structures. High temperature measurements with linear behavior are observed namely in un-doped fibers, i.e., with a pure silica composition. Three new configurations are presented as possible solutions to be considered in extreme conditions.

2013

Wireless IEEE 802.11-based networking approaches for industrial networked systems

Autores
Moraes, R; Vasques, F;

Publicação
Embedded Computing Systems: Applications, Optimization, and Advanced Design

Abstract
During the last few years, the demand for Real-Time (RT) communication has been steadily increasing due to a wide range of new applications. Remarkable examples are VoIP (Voice over IP) and Networked Control Systems (NCS). For such RT applications, the support of timely communication services is one of the major requirements. The purpose of this chapter is to survey the state-of-the-art on RT communication in CSMA-based networks and to identify the most suitable approaches to deal with the requirements imposed by next generation communication systems. This chapter focuses on one of the most relevant solutions that operate in shared broadcast environments, according to the CSMA medium access protocol, the IEEE 802.11 standard. From this survey, it becomes clear that traditional CSMA-based networks are not able to deal with the requirements imposed by next generation communication systems. More specifically, they are not able to handle uncontrolled traffic sources sharing the same broadcast environment. © 2013, IGI Global.

2013

An Empirical Study on Immersive Prototyping Dimensions

Autores
Moreira, S; José, R; Campos, JC;

Publicação
HCI (1)

Abstract
Many aspects of the human experience of ubiquitous computing in built environments must be explored in the context of the target environment. However, delaying evaluation until a version of the system can be deployed can make redesign too costly. Prototypes have the potential to solve this problem by enabling evaluation before actual deployment. This paper presents a study of the design space of immersive prototyping for ubiquitous computing. It provides a framework to guide the alignment between specific evaluation goals and specific prototype properties. The goal is to understand the potential added-value of 3D simulation as a prototyping tool in the development process of ubiquitous computing environments. © 2013 Springer-Verlag.

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