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Publicações

2018

Immersive Edition of Multisensory 360 Videos

Autores
Coelho, H; Melo, M; Barbosa, L; Martins, J; Teixeira, MS; Bessa, M;

Publicação
Trends and Advances in Information Systems and Technologies - Volume 2 [WorldCIST'18, Naples, Italy, March 27-29, 2018]

Abstract
The current technologic proliferation has originated new paradigms concerning the production and consumption of multimedia content. This paper proposes a multisensory 360 video editor that allows producers to edit such contents with high levels of customization. This authoring tool allows the edition and visualization of 360 video with the novelty of allowing to complement the 360 video with multiple stimuli such as audio, haptics, and olfactory. In addition to this multisensory feature, the authoring tool allows customizing individually each of the stimuli to provide an optimal multisensory user experience. A usability evaluation has revealed the pertinence of the editor, where it was verified an effectiveness rate of 100%, only one help request out of 10 participants, and positive efficiency. Satisfaction-wise, results equally revealed high level of satisfaction as the average score was 8.3 out of 10. © Springer International Publishing AG, part of Springer Nature 2018.

2018

Context-aware tourism technologies

Autores
Leal, F; Malheiro, B; Burguillo, JC;

Publicação
KNOWLEDGE ENGINEERING REVIEW

Abstract
Nowadays travellers can benefit from the computing capabilities, collection of on board sensors and ubiquitous Internet access provided by mobile devices. These are the three pillars of any tourist support system since they provide the power, means and data to establish the local user context, to access remote services and to provide value-added user-centred context-aware applications. However, making sense of the user context data is not straightforward, as it requires dedicated knowledge acquisition and knowledge representation solutions. Besides, the range and diversity of available data sources is huge, requiring appropriate knowledge processing techniques to provide addequated tourism services. This article presents an updated review, and a comparison of recent context-aware tourism applications (CATA), including supporting technologies; and considering four possible dimensions: knowledge acquisition, knowledge representation, knowledge processing and knowledge-based services. We propose and apply a CATA analysis framework, contemplating these four dimensions to the applications found in the literature. This survey constitutes, not only, a state of the art review on tourism mobile applications, but, also, anticipates the latest development trends in tourism-related applications.

2018

Deep Image Segmentation by Quality Inference

Autores
Fernandes, K; Cruz, R; Cardoso, JS;

Publicação
2018 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS (IJCNN)

Abstract
Traditionally, convolutional neural networks are trained for semantic segmentation by having an image given as input and the segmented mask as output. In this work, we propose a neural network trained by being given an image and mask pair, with the output being the quality of that pairing. The segmentation is then created afterwards through backpropagation on the mask. This allows enriching training with semi-supervised synthetic variations on the ground-truth. The proposed iterative segmentation technique allows improving an existing segmentation or creating one from scratch. We compare the performance of the proposed methodology with state-of-the-art deep architectures for image segmentation and achieve competitive results, being able to improve their segmentations. © 2018 IEEE.

2018

Consumo de Canábis: craving e a relação com ansiedade, stresse e depressão

Autores
Vasconcelos-Raposo, J; Couto, S; Formiga, N; Teixeira, CM;

Publicação
Actualidades en Psicología

Abstract
A canábis é a substância ilícita mais consumida em Portugal com um início de consumo muito precoce. O craving é considerado um dos factores fundamentais ligados ao consumo de canábis, associando-se à depressão, a ansiedade e ao stresse. Espera-se que nível de craving e sexo se relacionem com a depressão, ansiedade e stresse numa amostra de consumidores portugueses. A amostra foi constituída por 143 consumidores da zona Norte do país e os dados recolhidos através de questionários online (DASS-21 e o MCQ-SF). Os resultados permitem concluir que a emocionalidade, a intencionalidade e a compulsividade relacionaram-se positivamente com o nível do craving, bem como, com o stresse e a depressão. Quanto ao número de anos de consumo, constatou-se um efeito significativo, de dimensão média, na ansiedade.

2018

An indoor navigation architecture using variable data sources for blind and visually impaired persons

Autores
Gomes, JP; Sousa, JP; Cunha, CR; Morais, EP;

Publicação
2018 13TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)

Abstract
Contrary to outdoor positioning and navigation systems, there isn't a counterpart global solution for indoor environments. Usually, the deployment of an indoor positioning system must be adapted case by case, according to the infrastructure and the objective of the localization. A particularly delicate case is related with persons who are blind or visually impaired. A robust and easy to use indoor navigation solution would be extremely useful, but this would also be particularly difficult to develop, given the special requirements of the system that would have to be more accurate and user friendly than a general solution This paper presents a contribute to this subject, by proposing a hybrid indoor positioning system adaptable to the surrounding indoor structure, and dealing with different types of signals to increase accuracy. This would permit lower the deployment costs, since it could be done gradually, beginning with the likely existing Wi-Fi infrastructure to get a fairy accuracy up to a high accuracy using visual tags and NFC tags when necessary and possible.

2018

Single-Phase AC-DC-AC Multilevel Converter for Grid Overvoltage Based on an H-Bridge Connected in Series to the Five-Leg Converter

Autores
Queiroz, ADD; Jacobina, CB; Maia, ACN; Melo, VFMB; de Freitas, NB; Carlos, GAD;

Publicação
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS

Abstract
In this work, an ac-dc-ac multilevel power converter for grid overvoltage is investigated. The developed configuration is composed of one single-phase ac-dc-ac three-leg module and two H-bridges. One of them is connected to the shared part of the system to generate multilevel voltages at the input and output of the structure, and the other one is connected to the grid side to compensate the grid overvoltage. The converter can be employed in applications with same input and output frequency, such as uninterrupted power supply and unified power quality conditioner without isolation transformer. System model, a space vector pulsewidth modulation strategy to balance the individual dc-link voltages, and an overall control strategy to adjust the grid power factor, the amplitude, and the frequency of the load voltage are presented. The proposed converter is compared in terms of harmonic distortion and semiconductor losses with conventional structures. Simulation and experimental results demonstrate the operation of the proposed topology.

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