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Publications

2020

Manipulation of the Fundamental Frequency Micro-Variations using a Fully Parametric and Computationally Efficient Speech Model

Authors
Silva, JP; Oliveira, MA; Cardoso, CF; Ferreira, AJ;

Publication
IEEE Workshop on Signal Processing Systems, SiPS: Design and Implementation

Abstract
In this paper, we present a computationally efficient and fully parametric harmonic speech model that is suitable for real-time flexible frame-based analysis and synthesis implementation in the frequency domain. We carry out a performance comparison between this vocoder and similar ones, such as WORLD and HPMD. Then, a deliberate manipulation of the speaker's fundamental frequency micro-variations is performed in order to understand in which way it conveys prosodic and idiosyncratic information. We conclude our discussion by evaluating the impact of these manipulations through the realization of perceptual tests. © 2020 IEEE.

2020

Electronic games as a touristic promotional tool

Authors
Esteves F.; Brito P.Q.;

Publication
Handbook of Research on Resident and Tourist Perspectives on Travel Destinations

Abstract
According to the World Tourism Organization (UNWTO), in 2017 tourism had the greatest international growth in seven years, and in 2018, international tourism grew 5% reaching the mark of 1.4 billion, a figure reached two years earlier than predicted. At the same time, in the last 40 years, the video game industry has grown steadily, with games beginning to be seen as one of the primary sources of entertainment. However, there are still few studies analyzing the impact of advertising tourist destinations on digital platforms such as video games. The use of video games in the tourist context may be an inspirational tool, supporting the development of new advertising strategies for tourism marketing. Although the connection between tourism and cinema is widely documented, little research has demonstrated a credible correlation between video games and tourists' attitude towards destinations.

2020

GNAO: An MCAO facility for Gemini North

Authors
Sivo G.; Palmer D.; Scahrwächter J.; Andersen M.; Provost N.; Marin E.; Van Dam M.; Chinn B.; Chirre E.; Cavedoni C.; Schneider T.; Kang S.; Hirst P.; Rambold W.; Ebbers A.; Gigoux P.; Catala L.; Hayward T.; Blakeslee J.; Roe H.; Lotz J.; Kleinman S.; Sivanandam S.; Krause A.; Ammons M.; Trujillo C.; Packham C.; Marchis F.; Christou J.; Jee J.; Bally J.; Pierce M.; Puzia T.; Turri P.; Kim H.; Schwamb M.; Dupuy T.; Diaz R.; Carrasco R.; Neichel B.; Correia C.; Steinbring E.; Rigaut F.; Véran J.P.; Chun M.; Lamb M.; Chapman S.; Esposito S.; Fusco T.;

Publication
Proceedings of SPIE - The International Society for Optical Engineering

Abstract
Gemini Observatory has been awarded a major funding from the National Science Foundation to build a complete new state of the art multi-conjugate adaptive optics system for Gemini North. The system will be designed to provide an MCAO facility delivering close to diffraction limit correction in the near-infrared over a 2 arcminutes field of view and feed imaging and spectroscopic instruments. We present in this paper the results of the conceptual design phase with details on the new proposed laser guide star facilities and adaptive optics bench. We will present results on the performance simulation assessments as well as the developed selected science cases.

2020

A Study on Imbalanced Data Streams

Authors
Aminian, E; Ribeiro, RP; Gama, J;

Publication
MACHINE LEARNING AND KNOWLEDGE DISCOVERY IN DATABASES, ECML PKDD 2019, PT II

Abstract
Data are growing fast in today's world and great portion of that is in the form of stream. In many situations, data streams are imbalanced making it difficult to use with classical data mining methods. However, mining these special kinds of streams is one of the most attractive research area. In this paper, we propose two algorithms for learning from imbalanced regression data streams. Both methods are based on Chebychev's inequality but in a different way. The first method, under-samples from the frequent target value examples while the second method over-samples the rare and extreme target value examples. This way, the learner will focus in the rare and more difficult cases. We applied our methods to train regression models using two benchmark datasets and two well-known regression algorithms: Perceptron and FIMT-DD. Our obtained results from the simulations indicate the usefulness of our proposed methods.

2020

Biot-Granier Sensor: A Novel Strategy to Measuring Sap Flow in Trees

Authors
Siqueira, JM; Paco, TA; da Silva, JM; Silvestre, JC;

Publication
SENSORS

Abstract
The Biot-Granier (Gbt) is a new thermal dissipation-based sap flow measurement methodology, comprising sensors, data management and automatic data processing. It relies on the conventional Granier (Gcv) methodology upgraded with a modified Granier sensor set, as well as on an algorithm to measure the absolute temperatures in the two observation points and perform the Biot number approach. The work described herein addresses the construction details of the Gbt sensors and the characterization of the overall performance of the Gbt method after comparison with a commercial sap flow sensor and independent data (i.e., volumetric water content, vapor pressure deficit and eddy covariance technique). Its performance was evaluated in three trials: potted olive trees in a greenhouse and two vineyards. The trial with olive trees in a greenhouse showed that the transpiration measures provided by the Gbt sensors showed better agreement with the gravimetric approach, compared to those provided by the Gcv sensors. These tended to overestimate sap flow rates as much as 4 times, while Gbt sensors overestimated gravimetric values 1.5 times. The adjustments based on the Biot equations obtained with Gbt sensors contribute to reduce the overestimates yielded by the conventional approach. On the other hand, the heating capacity of the Gbt sensor provided a minimum of around 7 degrees C and maximum about 9 degrees C, contrasting with a minimum around 6 degrees C and a maximum of 12 degrees C given by the Gcv sensors. The positioning of the temperature sensor on the tip of the sap flow needle proposed in the Gbt sensors, closer to the sap measurement spot, allow to capture sap induced temperature variations more accurately. This explains the higher resolution and sensitivity of the Gbt sensor. Overall, the alternative Biot approach showed a significant improvement in sap flow estimations, contributing to adjust the Granier sap flow index, a vulnerability of that methodology.

2020

BMI, waist-to-height ratio and body fat mass in older adults: results from the Pronutrisenior project

Authors
Correia, F; Oliveira, BMPM; Poinhos, R; Sorokina, A; Afonso, C; Franchini, B; Pereira, B; Fonseca, L; Sousa, M; Monteiro, A; de Almeida, MDV;

Publication
PROCEEDINGS OF THE NUTRITION SOCIETY

Abstract
AbstractNear 20% of the Portuguese population is aged 65 years or above, a value similar to most developed countries. This older adult population also suffers from obesity and obesity-related pathologies. The environment encompasses a set of obesity determinants and knowing the associations between the environment and obesity may help health professionals and caregivers to provide for the older adults.In this study, we aimed to relate anthropometric measures with socio-demographic data in older adults.This is a cross-sectional study using data from the Pronutrisenior project, collected in Vila Nova de Gaia, Portugal. The sample consists of 456 older adults, aged 65 to 92 years without cognitive impairment. The sample consisted of older adults living at their homes. Socio-demographic, clinical, geographical, and anthropometric data was collected. The statistical analysis used IBM-SPSS-22.0 and consisted on descriptive statistics, Pearson correlations and UniANOVA. Significantly results (p < 0.05) are reported.These older adults were mostly females (54.2%) with a mean age of 73.8 years (sd = 6.3), mean body mass index (BMI) of 29.1kg/m2 (sd = 4.8), mean waist-to-height ratio (WHtR) of 0.623 (sd = 0.073) and mean percentage of body fat mass (%BFM) of 40.7% (sd = 8.9%) for females and 30.2% (sd = 8.5%) for males. BMI, WHtR and %BFM were positively correlated. In this sample of older adults, higher values of these measures were associated to being female, younger, less educated; to having articular pains and respiratory problems, and not having insomnia, hypertension, chewing problems nor hearing problems; to drink more liquids but not consuming dairy products daily; to not take nutritional supplements but to take more medicines; to be without somebody to talk to and to be more dependent; and to live in a house without stairs to climb and to live near other older adults, and in a more urbanized area with streets with steeper slopes.In this sample of older adults, obesity is related with health characteristics and those are related with socio-demographic and geographical characteristics of the area of residence. Besides the identification of risk factors for the older adult population, this information may help designing health care policies that takes in consideration the physical and geographical characteristics of the neighbourhood of the area of residence of the older adults.

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