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.
- 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.
- 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.
- Biofuel for the energy efficiency on a building with small CCHPPublication . Galvão, João; Leitão, S.; Malheiro, S.; Gaio, T.This document reports the development of a technical and economical study related to the use of a renewable energy source - biomass for electricity and heat production. It is a hybrid and autonomous system with solar PV panels and environment friendly process aiming the reduction of energy demand, costs and emissions. This energy model is a new sustainable standard about efficiency consumption energy (electrical and thermal demands) of a small hotel building, with the biomass gasification cogeneration technology. This system is one relevant contribute to certify the building agree to the new national legislation of building thermal behaviour.
- Business Intelligence in higher education: Enhancing the teaching-learning process with a SRM systemPublication . Piedade, Maria Beatriz; Santos, Maribel YasminaPromoting students success requires the implementation of processes and mechanisms that allows the closely monitoring of the students academic activities. Although essential, the activities involved in this complex process do not take place in many higher education institutions due to the lack of appropriate practices and an adequate technological support that sustain these practices. To overcome this complex problem, a conceptual and a technological infrastructure was proposed and integrated into a Student Relationship Management (SRM) system. The SRM system is associated with Business Intelligence concepts and technologies used to obtain knowledge about the students and to support the decision making process. To validate the SRM system relevance, a set of applications cases were carried out in real contexts and supported by the implemented prototype. This paper presents some of the results obtained through the prototype implementation and on the analysis of the several actions that were carried out under the principles of the SRM practice.
- Characterization and testing of a shock absorber embedded sensorPublication . Ferreira, C.; Ventura, P.; Grinde, C.; Morais, R.; Valente, A.; Neves, C.; Reis, M.This article presents the characterization of a shock absorber embedded sensor (SAES) for real-time monitoring of the condition of vehicle shock absorbers in everyday use. A prototype system was built using a custom designed monolithic silicon combined accelerometer, pressure and temperature sensors. The characterization of the SAES was performed and the obtained results meet and even outperform the specification requirements. The SAES was installed in a shock absorber, with adjustable damping properties, and submitted to road tests. Results show that the condition of a shock absorber can be effectively assessed with the presented SAES. Ensuring that shock absorbers are replaced before reach unacceptable condition, this system will increase onboard comfort and vehicle safety.
- Clock Repeater Characterization for Jitter-Aware Clock Tree SynthesisPublication . Figueiredo, Monica; Aguiar, Rui L.This paper presents a simple jitter model for clock repeaters. The model is scalable and technology independent, which makes it suitable for integration in current clock tree synthesis algorithms. It is based on the timing characterization of a reference inverter, which can be performed for different process corners to account for process variability. Simulation results show that the model is accurate to within 10% for the most common inverter and NAND based repeaters.