ESTG - Comunicações em conferências e congressos internacionais
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Percorrer ESTG - Comunicações em conferências e congressos internacionais por Objetivos de Desenvolvimento Sustentável (ODS) "07:Energias Renováveis e Acessíveis"
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- A 1.2V 900nW conductance converterPublication . Miranda, Nuno; Morais, RaulThis article describes a new electrical conductance converter method suitable for very low power applications, where energy constraints prevails over speed and measurement accuracy. Method idea gather voltage time integration and shopper stabilization techniques to process noisy low amplitude signals and to overcome severe limitations of weak inversion channel CMOS circuitry. Main features and tradeoffs are exploited. A 1.2V ASIC implementation on standard 0.35μm CMOS schematics is also presented. Post-layout simulations shows a total power consumption lower than 900nW including current source excitation inherent to the conductance measurement. Such low power consumption allows the measurement of several physical parameters on self-powered wireless networks.
- 3D video shot boundary detection based on clustering of depth-temporal featuresPublication . Ferreira, Lino; Assunção, Pedro; Cruz, Luis A. da SilvaThis paper proposes an algorithm for automatic detection of 3D video shots with different perceptual features. The proposed algorithm is able to identify distinct three-dimensional visual scenes by detecting 3D video shot boundaries based on clustering of depth-temporal features. A combination of texture variation along the temporal dimension and depth variance is used by K-means clustering to find the stereo frames which comprised the 3D scene boundaries. An important characteristic of the proposed algorithm in comparison with others published in the literature for temporal segmentation of classic 2D video is that no thresholds are used in the decision processes neither training data sets. The experimental results show that the proposed method is capable of achieving high recall (e.g., 0.95) and precision rate (e.g., 1.0) in video sequences with both sharp and smooth 3D scene transitions.
- A European Portuguese Children Speech Database for Computer Aided Speech TherapyPublication . Lopes, Carla, Alexandra Calado Lopes; Veiga, Arlindo; Perdigão, FernandoThis paper introduces a European Portuguese speech database containing spoken material recorded from children. The need for such database arose from the need of train phone models for the development of a computer aided speech therapy system. Articulatory disorders affect a significant number of children in pre-school age. We propose a system intended to assist and reinforce the conventional speech therapy programs. Through the systematic use of games, it learns the phones where the child has more difficulty to pronounce. The child is then taken to train the production of those phones by playing games. Another interest of a children speech database is that accurate children's phone recognition is only possible using training data that reflects the population of users. It is a difficult task due to the high pitch of children's speech
- ACTIVE CFRP-BASED CONFINEMENT STRATEGIES FOR RC COLUMNS WITH RECTANGULAR CROSS SECTIONSPublication . Agante, Marta; Júlio, Eduardo N. B. S.; Barros, Joaquim A. O.; Santos, João M. C.FRP wrapping is a strengthening technique for RC columns mostly used when a significant confinement increase is required. This technique is extremely effective in the case of circular cross-sections, but of marginally effectiveness for rectangular cross-sections columns. The use of post-tensioned CFRP jackets was an attempt to improve the confinement effectiveness for rectangular RC columns, but the level of success has been quite limited. This paper analyzes the viability of using an expansive resin to introduce some level of post-tension in CFRP jacket. In a first step, the optimal percentage of water added to trigger the resin expansion was analyzed. Using the obtained optimal value of water, the influence on the level of jacket post-tension of the width of the gap between the concrete surface and the CFRP jacket was investigated, and its timedependent sensitivity was assessed. Finally, the compression behaviour of specimens confined with this technique was assessed by performing experimental tests. The obtained results revealed that the adopted expansive resin is not an effective technique to assure high levels of post-tension in CFRP jackets for the concrete confinement.
- Ad-hoc changes in IoT-aware business processesPublication . Domingos, Dulce; Martins, Francisco; Martinho, Ricardo; Silva, MárioThe Internet of Things makes it possible to adapt the behaviour of business processes in response to real-time context updates. In addition, physical items can run and validate parts of the business processes and optimise their execution, while reducing message transmissions. State-of-the-art event-driven, service-oriented architecture approaches contribute to enabling inter-organisational collaboration and interoperability of heterogeneous hardware, but their applicability is limited to preplanned, well-structured processes. We take a step forward by supporting ad-hoc changes within business processes, considering changes in the state of the Things; likewise, whenever needed, the software controlling the behaviour of sensors may be dynamically reconfigured as a result of changes in the functional specifications of business processes.
- Adaptive coding tree for complexity control of high efficiency video encodersPublication . Correa, G.; Assunção, P.; Silva Cruz, L. A. da; Agostini, L.The emerging HEVC standard introduces several techniques which increase compression efficiency in comparison to its predecessors. However, such advances are accompanied by increases in computational complexity, limiting the encoder use in computational or power-constrained devices. This paper proposes a novel complexity control method for the future HEVC encoders based on a dynamic adjustment of the newly proposed coding tree structures. The relationship between coding tree depths and the encoding complexity is explored to selectively constrain encoding possibilities in order to not exceed a predefined complexity target. Experimental results show that the encoder computational complexity can be downscaled to 60% with a bit rate increase under 3.5% and a PSNR decrease under 0.1 dB.
- Agile Accessibility Assessment: Development and Evaluation of Native SoftwarePublication . de Sousa e Silva, João; Pereira, António; Ferreira, Rui Bragança; Gonçalves, RamiroThe information and communication technologies (ICT) have the potential to improve the quality of life of individual with functional particularities, potentiating their activity in society, as well supplying the conditions for a prolonged active life, counter acting the natural age related lost of faculties. As such, the software component – of ICT – is lacking a good and attentive construction to these functioning details which, often, are of difficult assessment. Adding to these constrains, the existing information is, not exclusively but especially, focused on Web contents. Attending to these matters, a checklist of proposals has been elaborated, and presented in this paper, that tries to cover these flaws, allowing for an evaluation of the accessibility of Integrated Development Environments (IDE), their capacity of generating accessible software – native software and not Web contents -, and even the accessibility of the final product – the native software. Conceived through the reutilization and inspired on the general knowledge created by the Web Accessibility Initiative (WAI), the drafts of this checklist are easily understandable and applicable. With the objective of facilitating the work of information systems technician who may already have concerns regarding these topics, it further has the important potential of encouraging agents to initiate themselves into the cares that this are requires.
- Application for monitoring primary energy resources based on open source softwarePublication . Álvarez, Marcelo; Ortiz, Diego; Sánchez, Wilson; Rivas, David; Aimacaña, Sixto; Sango, Wilson; Granizo, Rosa; Vayas, Germania; Toasa, RenatoIn the project a monitoring system where a study or analysis of the quantity, availability and performance of the primary energy resource is made, for which a monitoring system of primary energy resources developed in the General campus Guillermo Rodriguez Lara is implemented of the Universidad de las Fuerzas Armadas - ESPE, for which sophisticated equipment that capture the signals of environmental variables is used, the objective is to develop a software-based open source handling such information application, and allows obtaining and storing environmental data, to conduct an analysis of them favoring decision-making, incorporating them into a web platform, the application also calculates the energy produced the day before, thus achieving construct an assessment tool parameters for future projects, which serve the information obtained in the feasibility analysis to implement projects related to renewable energy, thus contributing to energy development.
- Assessing the influence of uncertainty in land cover mapping and digital elevation models on flood risk mappingPublication . Gonçalves, Luísa M.S.; Fonte, Cidália C.; Gomes, RicardoThis paper proposes an approach to assess the influence of the uncertainty present in the parameters dependent on the land cover and elevation data over the peak flow values and the subsequent delineation of flooded areas. The proposed approach was applied to produce vulnerability and risk maps that integrate uncertainty for the urban area of Leiria, Portugal. A SPOT-4 satellite image and DEMs of the region were used. The peak flow was computed using the Soil Conservation Service method and HECHMS, HEC-RAS, Matlab and ArcGIS software programs were used. The analysis of the results obtained for the presented case study enables the identification of the order of magnitude of uncertainty associated to the watershed peak flow value and the identification of the areas which are more susceptible to flood risk to be identified.
- Asymmetric 3D video coding using regions of perceptual relevancePublication . Pinto, Luis; Assunção, PedroThis paper proposes an extension of the concept of asymmetric coding by introducing region-based asymmetry in the spatial dimension of stereoscopic video. The method relies on stereo image regions with different relevance for 3D perception defined by spatial binary masks. It is demonstrated that to a certain extent, regions with lower perceptual relevance can be encoded with lower quality than the remaining ones without harming the perceived quality. 3D video streams with different asymmetric quality combinations were produced and then evaluated through subjective testing. The results show that it is possible to further exploit traditional asymmetric coding while maintaining the same perceptual quality. Depending on the sequence content, this work leads to the conclusion that it is possible to reduce the bitrate of the auxiliary view up to 20 percent without being perceived by users.