ESTG - Comunicações em conferências e congressos internacionais
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- Soccer sprint and agility are similar between pre- and postpubescent boys, when ball is consideredPublication . Morouço, P.G.; Dias, R.; Menino, V.Introduction Scientific evidence suggests that specific physiological demands and anthropometrical prerequisites result in the selection of young players based onenhanced physiological performances and anthropometricaladvantage (1). How-ever, the competitive demands are not the same in youth categories, inducing different physical and physiological profiles from those of adult players (2). The purpose of the present study was to analyze possible differences in speed, agility and jump height of pre- and postpubescent soccer players.
- Strength or technique: What should be trained to increase swimming speed?Publication . Morouço, P.G.; Marinho, D.A.; Marques, M.C.Introdution Swimming speed is both dependent on strength and technique. Indeed, the balance between these two major factors may explain the success or failure in competitive events. However, competitive events vary enormously in terms of distance, and therefore time and intensity. Thus, an optimal level of strength is essential for successful performance in swimming (1), varying according to the distance to be swam (2). But how can swimming coaches track the balance between these two factors? And how can be identified if the swimmer must focus in one of them, in detriment of the other?
- EasyBDI: Near Real-Time Data Analytics over Heterogeneous Data SourcesPublication . Silva, Bruno; Moreira, José; Costa, Rogério Luís de C.The large volume of currently available data creates several opportunities for sciences and industry, especially with the application of data analytics. But also raises challenges that make unfeasible the use of batch-based ETL processes. Indeed, near real-time data analytics is a requirement in several domains as an alternative to traditional data warehouses. In the last years, big data platforms have been developed to enable query execution over distributed data sources. However, they do not deal with subject-oriented analysis, do not provide data distribution transparency, or do not assist with schema mapping and integration. In this demonstration, we present EasyBDI. It's a near real-time big data analytics prototype that enables users to run queries over heterogeneous data sources based on global logical abstractions created by the system and provides some usual concepts of data warehouse systems, like facts and dimensions. We use two motivating scenarios, one based on three years of real data on photovoltaic energy production and consumption, and the other based on the SSB+ benchmark. We will also present implementation challenges, issues, solutions, and insights.
- Reconstructing Conimbriga - Digital CantaberPublication . Ferreira, César; Rodrigues, Nuno; Gonçalves, Alexandrino; Hipólito-Correia, VirgílioBeing the ancient cultural heritage structures and artefacts so full of detail and relevance to studies related to our past, it would be desirable to have precise virtual replicas that could be freely explored without endangering important pieces of history. However, the costs to produce three-dimensional environments are sometimes discouraging, due to the significant cost of some 3D authoring tools, and to the time necessary to manually produce the models. This paper presents a low-cost alternative to the classic manual modelling process, towards the production of highly detailed virtual models, by using open source software and a lowcost moving depth camera. The ambition is the dissemination of our cultural heritage legacy, making it accessible, not only to experts, but also to the general public, without requiring any high-performance hardware, authoring software or professional 3D skills. For the visualization, our virtual reconstructions will be available through a three-dimensional live model viewer, based on recent technologies such as HTML5 and WebGL. Those may be triggered from a wide variety of device, contributing in this way to a true democratization of history knowledge. The proposed approach was applied to create a virtual model of the so-called "House of Cantaber".
- The influence of knowledge management on the result of innovation of companies in the mold industriesPublication . Ferreira, Vítor Hugo Santos; Marques, Alzira Maria Ascensão; Espírito Santo, Pedro Manuel do; Silva, Sara Fernandes daIn today's business world, knowledge and innovation are key factors for the success of organizations. Knowledge stock alone does not generate a competitive advantage to companies, but the way it is used might create it. It is through the wide network of relationships that involves the organization that innovations emerge. These two concepts are intertwined, since for the innovation process to be successful, there must first be an effective knowledge management, which involves knowledge acquisition, application and sharing. In this context and based on a sample of 36 companies in the mold making sector in Portugal (one industry where Portugal is the 8th top producer in the world), a confirmatory research work was carried out with the aim of studying the impact of knowledge management on innovation performance. For this purpose, we used a quantitative methodology based on a survey. Through the estimation of a structural equations model, using SmartPLS software, we found that knowledge acquisition has a positive influence on knowledge sharing, which in turn is positively reflected in its application, which positively impacts innovation in performance in Portuguese plastic injection mold making companies-these results are in line with similar studies carried out in different contexts. Consequently, knowledge, considered as an intangible asset, must be managed effectively and efficiently, in order to create value through innovation, a determinant of competitiveness in an activity sector that creates customized solutions for its customers. Despite of the small sample size, these results highlight the importance of effectively managing the acquisition.
- Acoustic Similarity Scores for Keyword SpottingPublication . Veiga, Arlindo; Lopes, Carla; Sá, Luís; Perdigão, FernandoThis paper presents a study on keyword spotting systems based on acoustic similarity between a filler model and keyword model. The ratio between the keyword model likelihood and the generic (filler) model likelihood is used by the classifier to detect relevant peaks values that indicate keyword occurrences. We have changed the standard scheme of keyword spotting system to allow keyword detection in a single forward step. We propose a new loglikelihood ratio normalization to minimize the effect of word length on the classifier performance. Tests show the effectiveness of our normalization method against two other methods. Experiments were performed on continuous speech utterances of the Portuguese TECNOVOZ database (read sentences) with keywords of several lengths.
- How knowledge sharing mediates the effects of internal marketing on customer orientationPublication . Espírito Santo, Pedro Manuel do; Ferreira, Vítor Hugo Santos; Marques, Alzira Maria AscensãoA growing body of research has demonstrated the growing importance given to two areas of business management: internal marketing and knowledge management. Nevertheless, these seldom areas are considered together. This paper explores the importance of knowledge sharing as a mediating variable in the relationship between internal and external marketing. Thus, our research presents an investigation model where the influence of tacit knowledge sharing and explicit knowledge sharing are presented. The data of this research was collected from the employees of a company in the logistics sector, through a face-to-face questionnaire. The proposed research hypotheses were tested empirically through structural equation modeling (PLS-PM) with a bootstrapping procedure. The results demonstrate that internal marketing has a positive effect on knowledge sharing and, consequently, on customer orientation. In this sense, through this paper, managers can verify the importance of knowledge sharing (tacit and explicit) in leveraging the effects of internal marketing in customer orientation.
- A review on the electromagnetic characterisation of building materials at micro- and millimetre wave frequenciesPublication . Ferreira, David; Cuiñas, Iñigo; Caldeirinha, Rafael F. S.; Fernandes, Telmo R.This paper presents a review on some of the most relevant scientific publications on the topic of electromagnetic characterisation of building materials at micro- and millimetre wave frequencies. These published papers provide measurement results and techniques for a wide range of frequencies (2 to 62.4 GHz) for the most common building materials used in today's civil engineering, allowing the extraction of their approximate dielectric parameters such as the relative permittivity value. This review focuses on materials such as bricks, concrete, plasterboard, glass, plywood and chipwood, as these have been characterised by a few different authors. It is the aim of this paper to gather these results and model the dielectric permittivity for various frequencies and material type. Finally, the paper presents a critical analysis on the discrepancy of results found in the literature.
- A mixed time-frequency RF simulation technique based on numerical time-slot partitioningPublication . Oliveira, Jorge F.The increasing complexity of radio frequency (RF) architectures and the continuous push to profit from digital signal-processing techniques, have been addressing new challenges to circuit-level simulation. This paper describes the most relevant details of a time-frequency simulation technique specially conceived for the efficient numerical simulation of circuits whose stimuli are turned on and off for unknown periods of time, as is the case of RF circuits managing signals coded in some on-off digital scheme. The proposed technique is based on a time-slot partition stratagem with automatic switching between different numerical schemes (multitime envelope transient harmonic balance and time-step integration) along the simulation process, according to the on-off state of the circuits’ stimuli. Simulation tests performed in an illustrative application example, an on-off amplitude shift keying (ASK/OOK) transmitter used in low-power applications, as radio frequency identification (RFID) or biomedical imaging, revealed significant gains in computational speed over commercial computer-aided design tools.
- Production and processing of thermoplastic based towpregs for commercial and advanced marketsPublication . Nunes, J.P.; Novo, P.J.; Silva, J.F.; Marques, A.T.In this work continuous fibre reinforced thermoplastic matrix towpregs were produced for commercial markets and advanced markets. The former based on glass fibre reinforced polypropylene matrix (GF/PP) and the latter on carbon fibre Primospire® matrix (CF/P). Primospire® is an amorphous highly aromatic material specifically developed by Solvay Advanced Polymers for application in advanced markets. Both towpregs were processed into composite parts by different technologies. The mechanical properties determined on the final composites were compared with the theoretical predictions and have shown to be acceptable for the targeted markets.