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Publications

Publications by CTM

2014

MobBIO: A Multimodal Database Captured with a Portable Handheld Device

Authors
Sequeira, AF; Monteiro, JC; Rebelo, A; Oliveira, HP;

Publication
PROCEEDINGS OF THE 2014 9TH INTERNATIONAL CONFERENCE ON COMPUTER VISION, THEORY AND APPLICATIONS (VISAPP 2014), VOL 3

Abstract
Biometrics represents a return to a natural way of identification: testing someone by what (s) he is, instead of relying on something (s) he owns or knows seems likely to be the way forward. Biometric systems that include multiple sources of information are known as multimodal. Such systems are generally regarded as an alternative to fight a variety of problems all unimodal systems stumble upon. One of the main challenges found in the development of biometric recognition systems is the shortage of publicly available databases acquired under real unconstrained working conditions. Motivated by such need the MobBIO database was created using an Asus EeePad Transformer tablet, with mobile biometric systems in mind. The proposed database is composed by three modalities: iris, face and voice.

2014

Experimental Setup for Electromagnetically Induced Transparency Observation in Hollow-Core Fibers

Authors
Tiburcio, BD; Fernandes, GM; Monteiro, JM; Rodrigues, S; Carvalho, MI; Facao, M; Ferreira, M; Pinto, AN;

Publication
SECOND INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
We developed a system to investigate resonant nonlinear optical interactions in acetylene molecules, confined in a hollow-core photonic crystal fiber (HC-PCF), using light injection through a low-loss splice from one end of the fiber, allowing us to work at low power. Electromagnetically induced transparency (EIT) was observed in the 1500 nm telecommunications window.

2014

Dynamics of blueshifted floating pulses in gas-filled hollow-core photonic crystal fibers

Authors
Facao, M; Carvalho, MI;

Publication
APPLIED PHYSICS B-LASERS AND OPTICS

Abstract
Frequency blueshifting was recently observed in light pulses propagating on gas-filled hollow-core photonic crystal fibers where a plasma has been produced due to photoionization of the gas. One of the propagation models that is adequate to describe the actual experimental observations is here investigated. It is a nonlinear Schrodinger equation with an extra term, to which we applied a self-similar change of variables and found its accelerating solitons. As in other NLS-related models possessing accelerating solitons, there exist asymmetrical pulses that decay as they propagate in some parameter region that was here well defined.

2014

Wi-Fi Broadband Maritime Communications Using 5.8 GHz Band

Authors
Lopes, MJ; Teixeira, F; Mamede, JB; Campos, R;

Publication
2014 UNDERWATER COMMUNICATIONS AND NETWORKING (UCOMMS)

Abstract
Current maritime communications rely on expensive or proprietary technology, such as satellite, WiMAX, and narrowband HF radios. Broadband communications are limited to the near shore 3G/4G coverage provided by mobile operators. The usage of unlicensed and IEEE 802.11 networks may provide ship owners a low-cost broadband access to the Internet offshore, enabling real-time navigation applications and voice/video communications, while increasing safety onboard. Also, they can support underwater communications by acting as a bridge between shore and devices operating underwater. In this paper we present a performance evaluation of IEEE 802.11n networks in the 5.8 GHz band in a maritime environment. A point-to-point link was established between a fishing ship and shore. From our tests, communication links up to 7 km at 1 Mbit/s are possible, showing the advantage of using long range IEEE 802.11 links for broadband maritime communications.

2014

Considering roughness to describe and generate vertical musical structure in content-based algorithmic-assisted audio composition

Authors
Bernardes, G; Davies, MEP; Guedes, C; Pennycook, B;

Publication
Proceedings - 40th International Computer Music Conference, ICMC 2014 and 11th Sound and Music Computing Conference, SMC 2014 - Music Technology Meets Philosophy: From Digital Echos to Virtual Ethos

Abstract
This paper examines the correlation between musical dissonance and auditory roughness-the most significant factor of psychoacoustic dissonance- and the contribution of the latter to algorithmic composition. We designed an empirical study to assess how auditory roughness correlates with human judgments of dissonance in natural musical stimuli on the sound object time scale. The results showed a statistically significant correlation between roughness and listeners' judgments of dissonance for quasi-harmonic sounds. This paper concludes by presenting two musical applications of auditory roughness in algorithmic composition, in particular to supervise the vertical recombination of sound objects in the software earGram. Copyright:

2014

Composing Music by Selection: Content-based Algorithmic-Assisted Audio Composition

Authors
Gilberto Bernardes de Almeida;

Publication

Abstract

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