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Publicações

2015

Frequency-domain parametric coding of wideband speech - A first validation model

Autores
Ferreira, A; Sinha, D;

Publicação
139th Audio Engineering Society International Convention, AES 2015

Abstract
Narrow band parametric speech coding and wideband audio coding represent opposite coding paradigms involving audible information, namely in terms of the specificity of the audio material, target bit rates, audio quality and application scenarios. In this paper we explore a new avenue addressing parametric coding of wideband speech, using the potential and accuracy provided by frequency-domain signal analysis and modeling techniques that typically belong to the realm of high-quality audio coding. A first analysis-synthesis validation framework is described that illustrates the decomposition, parametric representation and synthesis of perceptually and linguistically relevant speech components while preserving naturalness and speaker specific information.

2015

Cost-effective and lightweight mobile units for MixAR: a comparative trial among different setups

Autores
Padua, L; Narciso, D; Adao, T; Cunha, A; Peres, E; Magalhaes, L;

Publicação
CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS/INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT/CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERIS/PROJMAN / HCIST 2015

Abstract
Cultural heritage has arousing the interest of the general public (e.g. tourists), resulting in the increasing number of visitations to archaeological sites. However, many buildings and monuments are severely damaged or completely destroyed, which doesn't allow to get a full experience of "travelling in time". Over the years, several Augmented Reality (AR) approaches were proposed to overcome these issues by providing three-dimensional visualization of reconstructed ancient structures in situ. However, most of these systems were made available through heavy and expensive technological bundles. Alternatively, MixAR intends to be a lightweight and cost-effective Mixed Reality system which aims to provide the visualization of virtual ancient buildings reconstructions in situ, properly superimposed and aligned with real-world ruins. This paper proposes and compares different AR mobile units setups to be used in the MixAR system, with low-cost and lightweight requirements in mind, providing different levels of immersion. It was propounded four different mobile units, based on: a laptop computer, a single-board computer (SBC), a tablet and a smartphone, which underwent a set of tests to evaluate their performances. The results show that mobile units based on laptop computer and SBC reached a good overall performance while mobile units based on tablet and smartphone did not meet such a satisfactory result even though they are acceptable for the intended use. (C) 2015 The Authors. Published by Elsevier B.V.

2015

Kinect v2 Based System for Parkinson's Disease Assessment

Autores
Rocha, AP; Choupina, H; Fernandes, JM; Rosas, MJ; Vaz, R; Silva Cunha, JPS;

Publicação
2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)

Abstract
Human motion analysis can provide valuable information for supporting the clinical assessment of movement disorders, such as Parkinson's disease (PD). In this contribution, we study the suitability of a Kinect v2 based system for supporting PD assessment in a clinical environment, in comparison to the original Kinect (v1). In this study, 3-D body joint data were acquired from both normal subjects, and PD patients treated with deep brain stimulation (DBS). Then, several gait parameters were extracted from the gathered data. The obtained results show that 96% of the considered parameters are appropriate for distinguishing between non-PD subjects, PD patients with DBS stimulator switched on, and PD patients with stimulator switched off (p-value < 0.001, Kruskal-Wallis test). These results are markedly better than the ones obtained using Kinect v1, where only 73% of the parameters are considered appropriate (p-value < 0.001).

2015

Real time monitoring oxidation of transition metals with long period fiber gratings

Autores
Coelho, L; Viegas, D; Santos, JL; de Almeida, JMM;

Publicação
24TH INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS

Abstract
In this paper real time monitoring of oxidation of transition metals using long period fiber gratings (LPFG) is performed for nickel, copper, titanium, chromium and zinc. A thin layer is deposited over the LPFG with physical process deposition and is annealed up to 700 degrees C in air with a small oven. The whole oxidation process can be monitored by tracking the LPFG features of the attenuation band which results in an abrupt change when the oxidation occurs depending on the metal sample. A preliminary study to optimize optical fiber sensors sensitivity allowing choosing the correct oxide layer in a specific application is presented.

2015

Trace Element Content of Monovarietal and Commercial Portuguese Olive Oils

Autores
Gouvinhas, I; Machado, N; Cunha, M; Pereira, M; Matos, C; Gomes, S; Lopes, J; Martins Lopes, P; Barros, AIRNA;

Publicação
JOURNAL OF OLEO SCIENCE

Abstract
Olive (Olea europaea L.) represents one of the most important and ancient crops in the Mediterranean countries, being widely known due to the optimal organoleptic characteristics of its oil, besides the important health benefits assigned to this product in the last few years. Since olive oil composition, respecting specific trace elements, has a direct impact on the quality and safety of this product, eleven monovarietal and twelve commercial olive oils were analysed spectrometrically concerning their metal composition. Regarding quality parameters, the monovarietal olive oils display larger quantities of Mg, Fe, Mn, while the commercial samples are characterized by greater amounts of Na, Ca, Cu and Zn. In which respects to safety parameters, the commercial samples present higher values for Al and Pb, and lower quantities of Cd, respecting the monovarietal ones. The assessment of the values observed for the trace elements, resorting to multivariate statistical methods, allowed to clearly distinguish the type of olive oil production monovarietal or commercial blend. For this purpose, besides Cluster analysis, the data have been subjected to Principal Component Analysis undertaken for either all the evaluated parameters simultaneously, or the quality/safety parameters separately, both data sets allowing the discrimination of the samples.

2015

Accessible options for Deaf people in e-Learning platforms: technology solutions for Sign Language translation

Autores
Martins, P; Rodrigues, H; Rocha, T; Francisco, M; Morgado, L;

Publicação
PROCEEDINGS OF THE 6TH INTERNATIONAL CONFERENCE ON SOFTWARE DEVELOPMENT AND TECHNOLOGIES FOR ENHANCING ACCESSIBILITY AND FIGHTING INFO-EXCLUSION

Abstract
This paper presents a study on potential technology solutions for enhancing the communication process for deaf people on e-learning platforms through translation of Sign Language (SL). Considering SL in its global scope as a spatial-visual language not limited to gestures or hand/forearm movement, but also to other non-dexterity markers such as facial expressions, it is necessary to ascertain whether the existing technology solutions can be effective options for the SL integration on e-learning platforms. Thus, we aim to present a list of potential technology options for the recognition, translation and presentation of SL (and potential problems) through the analysis of assistive technologies, methods and techniques, and ultimately to contribute for the development of the state of the art and ensure digital inclusion of the deaf people in e-learning platforms. The analysis show that some interesting technology solutions are under research and development to be available for digital platforms in general, but yet some critical challenges must solved and an effective integration of these technologies in e-learning platforms in particular is still missing. (C) 2015 The Authors. Published by Elsevier B.V.

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