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- Use of User Generated Content to Support the Creation of Smart Tourist DestinationsPublication . Sousa, M. C. P. Belchior; Fernandes, A. L.; Pequeno, V. M.The Covid-19 pandemic had an unprecedented impact on the tourism industry. It is believed that the recovery of the sector goes through a strong investment in technologies that allow creating and managing tourists' perception of the virtual image of tourist destinations. This article proposes a discussion about the relevance of User Generated Content (UGC) to reveal the virtual image of a tourist destination, in order to contribute to the creation of a Smart Tourism Destination (STD). The virtual image is studied from the perspective of the public transport system due to the fact that its improvement is one of the objectives of the Tourism of Portugal strategic plan for the creation of a STD in the decade 2017 - 2027. The methodology used was qualitative, through a bibliographical research, in which the key factors of this theme were addressed. After the study carried out it was concluded that the exploration of UGCs can allow managers and regulatory and tourism promoting entities to extract a lot of interesting information about how to take better advantage of the technologies adopted to create value for tourists.
- A Sub-1 µA Low-Power, LowNoise Amplifier with Tunable Gain and Bandwidth for EMG and EOG Biopotential SignalsPublication . Vieira, Rafael; Martins, Ricardo; Horta, Nuno; Lourenço, Nuno; Póvoa, RicardoThis paper presents the design of a low-power low-noise amplifier for biomedical and healthcare applications, focusing on electromyography and electrooculography. The signals operate in different broad bands, yet follow an impulse-shape transmission, being suitable to be applied and detected by the same receiver. The biopotential sensing amplifiers usually have a major impact in power and noise performance of an analog front end; hence, the development of a low-noise amplifier with low-power consumption is of great importance. In this paper, the state-of-the-art amplifiers for biomedical applications are overviewed, and the proposed solution is presented. The proposed design has tunable cutoff frequency (FC) and gain, being adjustable for each type of signal. The circuit is designed in UMC 130 nm CMOS technology, supplied by 1.2 V, and consumes less than 1 μA. Post-layout simulation results show that, at the high FC of 2 kHz, the gain is 34 dB, presenting an input-referred noise of 1.476 μVrms corresponding to a noise efficiency factor (NEF) of 1.27. Whereas at the low FC of 20.91 Hz, the gain is 52.35 dB, the input-referred noise is 0.202 μVrms, and the NEF is 1.70.
- Edge Computing and Internet of Things Based Platform to Improve the Quality of Life of the Silver Economy on Leisure Cruise ShipsPublication . Plaza-Hernández, Marta; Sittón-Candanedo, Inés; Alonso, Ricardo S.; Martínez-de Iturrate, Luis C.; Prieto, Javier; Kravari, KalliopiToday, the Internet of Things, Big Data and Machine Learning are a regular part of people's daily lives, especially for the elderly or the so-called Silver Economy. There are more and more applications in which collecting and storing information about users (and their context) to produce classifications and predictions allows the optimisation of the services offered, improving the life quality of the citizens. In this sense, leisure cruises represent environments where it is necessary to provide quality services for a reasonable price. This requires understandings the behaviour of users both locally (i.e. each cruise) and globally (i.e. all cruises). In this respect, IoT, Big Data and Machine Learning are presented as ideal technologies for prediction-making and the improvement of the quality of services. However, on ships at sea the transfer rate of the Internet connection is limited. In this sense, Edge Computing allows taking part in the application computing to the Edge of the network, closer to the IoT layer. Data can be filtered and pre-processed in the Edge before it is transmitted to the Cloud, reducing its volume and the associated costs of its computing and storage in the Cloud. Machine Learning algorithms can also be applied to recognise patterns and anomalies on the Edge itself, even if the connectivity with the Cloud is lost. In this paper, we propose the design of a platform which aims to improve the quality of life of the elderly on leisure cruises.
- Publishing and Consuming Semantic Views for Construction of Knowledge GraphsPublication . Arruda, Narciso; Venceslau, Amanda; Lima da Cruz, Matheus Mayron; Vidal, Vânia Maria P.; Pequeno, ValériaThe main goal of semantic integration is to provide a virtual semantic view that is semantically connected to data so that applications can have integrated access to data sources through the virtual Knowledge Graph. A semantic view can be published on a semantic portal to make it reusable for building Knowledge Graphs for different applications. This paper takes the first step towards publishing a semantic view on a semantic portal. This paper has three main contributions. First, we introduce a vocabulary for specifying semantic views. Then, we introduce a vocabulary for specification and quality assessment of Knowledge Graph. Third, we describe an approach to automatize the construction of a high-quality Knowledge Graph reusing a semantic view.
- Ontologybased Question Answering Systems over Knowledge Bases: A Survey.Publication . Franco, Wellington; Avila, Caio Viktor Artur Oliveira S.; Maia, Gilvan; Brayner, Ângelo; Vidal, Vânia Maria P.; Carvalho, Fernando; Pequeno, Valéria M.Searching relevant, specific information in big data volumes is quite a challenging task. Despite the numerous strategies in the literature to tackle this problem, this task is usually carried out by resorting to a Question Answering (QA) systems. There are many ways to build a QA system, such as heuristic approaches, machine learning, and ontologies. Recent research focused their efforts on ontology-based methods since the resulting QA systems can benefit from knowledge modeling. In this paper, we present a systematic literature survey on ontology-based QA systems regarding any questions. We also detail the evaluation process carried out in these systems and discuss how each approach differs from the others in terms of the challenges faced and strategies employed. Finally, we present the most prominent research issues still open in the field.
- Towards Semi-automatic Generation of R2R MappingsPublication . Pequeno, Valéria M.; Vidal, Vânia M. P.; Vinuto, Tiago da SilvaTranslating data from linked data sources to the vocabulary that is expected by a linked data application requires a large number of mappings and can require a lot of structural transformations as well as complex property value transformations. The R2R mapping language is a language based on SPARQL for publishing expressive mappings on the web. However, the specification of R2R mappings is not an easy task. This paper therefore proposes the use of mapping patterns to semi-automatically generate R2R mappings between RDF vocabularies. In this paper, we first specify a mapping language with a high level of abstraction to transform data from a source ontology to a target ontology vocabulary. Second, we introduce the proposed mapping patterns. Finally, we present a method to semi-automatically generate R2R mappings using the mapping patterns.
- Effect of Fused Filament Fabrication Processing Parameters on The Mechanical Properties of PLA ComponentsPublication . Marat-Mendes, R.; Guedes, M.; Leite, M.; Baptista, R.This paper studies the influence of Fused Filament Fabrication processing parameters upon mechanical properties and microstructural features of processed PLA parts. The effect of extrusion temperature and raster angle were tested upon two PLA filaments of different trademarks, DoWire and BQ, using a commercial fused deposition extruder. The filling density, layer thickness and velocity were kept constant at 60 %, 0.2 mm and 40 mm/s, respectively. Results allowed to determine fused filament fabrication parameters resulting in increased mechanical performance of manufactured parts. Mechanical performance is higher when material is stored under controlled atmosphere before use, and when material deposition direction is aligned with applied load. Increasing the extrusion temperature also increases performance, by increasing deformation ability of PLA molecules. Obtained results contribute to accumulation of a property database and provide design guidance to the procurement of additive manufacturing products with enhanced mechanical strength.
- Experimental and Numerical Characterization of Stress-Strain Fields on Sandwich Beams, Subjected to 3PB and 4PBPublication . Marat-Mendes, R.; Martins, R.; Reis, L.
- LIF and SFS techniques for early detection of biofilms harmful for cultural heritagePublication . Utkin, A.B.; Chaves, Paulo; Fernades, L.; I.V., Pinto; Revez, M.J.Specific LIF (laser induced fluorescence) and SFS (spectral fluorescence signature) sensors have been developed for detecting biofilms colonizing the surface of cultural heritage artefacts. The sensors contribute to a large-scale monitoring and decision supporting system, which is being deployed for historical monument protection within the framework of the European project STORM.
- Efficient Yield Optimization Method using a Variable K-Means Algorithm for Analog IC SizingPublication . Canelas, A.; Martins, R.; Póvoa, R.; Lourenço, N.; Horta, N.This paper presents the study and implementation of a new efficient yield optimization technique for multi-objective optimization-based automatic analog integrated circuit sizing. The approach uses a commercial electrical simulator and standard process design kit (PDK) models to perform, during the optimization process, the same Monte Carlo (MC) simulations that designers use. The proposed yield estimation technique reduces the number of required MC simulations by using the k-means algorithm, with a variable number of clusters, to select only a handful potential solutions where the MC simulations are performed. Due to the use of a commercial simulator tool and foundry supplied PDK models the developed methodology provides the most accurate and reliable results, and also, the variable k-means algorithm is able to achieve 91% reduction in the total number of the MC simulations required for an optimization, when considering MC simulations for all solutions. Moreover, this new approach presents a 50% increase in speed performance when comparing to a previous yield optimization technique also using k-means and MC simulations.
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