ESTG - Comunicações em conferências e congressos internacionais
URI permanente para esta coleção:
Navegar
Percorrer ESTG - Comunicações em conferências e congressos internacionais por Objetivos de Desenvolvimento Sustentável (ODS) "09:Indústria, Inovação e Infraestruturas"
A mostrar 1 - 10 de 156
Resultados por página
Opções de ordenação
- 3D PARTICLE SYSTEMS FOR AUDIO APPLICATIONSPublication . Fonseca, NunoAlthough particle systems are well know for their use in computer graphics, their application in sound is very rare or almost non-existent. This paper presents a conceptual model for the use of particle systems in audio applications, using a full rendering system with virtual microphones: several virtual particles are spread over a virtual 3D space, where each particle reproduces one of the available audio streams (or a modified version), and the overall sound is captured by virtual microphones. Such system can be used on several audio-related areas like sound design, 3D mixing, reverb/impulse response design, granular synthesis, audio up-mixing, and impulse response up-mixing.
- 802.21-MPA-IMS ArchitecturePublication . Rodrigues, Carlos Miguel de Jesus; Rabadão, Carlos; Pereira, AntónioMobility has become a keyword nowadays with the evolution of mobile devices market and proliferation of realtime services. IP Multimedia Subsystem (IMS) is a single, standardized service framework that supports voice, video, data and messaging services, but does not provide seamless mobility for packet based sessions. This paper purposes an IMS architecture with IEEE 802.21 and media-independent pre-authentication (MPA) integrated. IEEE 802.21 can enable this seamless mobility in IMS and, additionally, MPA provides a secure handover optimization scheme, reducing, as a consequence, handover latency. The main goal of this architecture is to provide seamless and secure handovers between different access technologies in an IMS-based environment.
- Accuracy versus complexity of MARG-based filters for remote control pointing devicesPublication . Rasteiro, Miguel ; Costelha, Hugo; Conde Bento, Luis; Assunção, PedroAlthough most current pointing devices rely on relative rotation increments, absolute orientation allows for a more intuitive interaction. However, this is difficult to implement in low-energy consumption devices since accurate fusion filters are computationally intensive. This work presents a comparative study of low-complexity filters and state-of-the-art orientation tracking systems, enabling to access complexity versus portability. A relevant set of different MARG units currently available on the market were studied under systematic tests and human subjective user analysis. Experimental results show that it is possible to obtain similar accuracy using low-complexity filters to the ones observed with state-of-the-art orientation tracking systems. © 2015 IEEE.
- 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.
- Adjustment parameters of an internal combustion engine working with methanePublication . Dimitrov, R.; Bogdanov, K.; Wrobel, R.; Mihaylov, V.; Serrano, Luis; Institute of Physics PublishingThe paper presents a study of the variation of ignition advance when the engine works with methane and a comparison with values when the engine runs on gasoline. It is known that methane has a lower burning velocity than gasoline, and therefore, to obtain a maximal efficiency from the working process (the maximum value of cylinder pressure pz should be 7-15 degrees after TDC), ignition advance should be increased, as for different operating regimes this angle should be increased with different values. A gasoline engine has been studied and were measured and analysed the ignition advance at work with gasoline and methane, with optimal air-fuel ratio (α) for both fuels. Three-dimensional graphics of ignition advance variation across the rpm and load range were made. In conclusion, on the basis of the experiments, a table is produced, which presents the values of coefficients for change of base parameters of ignition advance for all engine operating modes, in dependence on rpm and load of the engine.
- Advances in thermoplastic pultruded compositesPublication . Novo, P.J.; Silva, J.F.; Marques, A.T.Pultrusion is a versatile continuous high speed production technology allowing the production of fibre reinforced complex profiles. Thermosetting resins are normally used as matrices in the production of structural constant cross section profiles. Although only recently thermoplastic matrices have been used in long and continuous fibre reinforced composites replacing with success thermosetting matrices, the number of their applications is increasing due to their better ecological and mechanical performance. Composites with thermoplastic matrices offers increased fracture toughness, higher impact tolerance, short processing cycle time and excellent environmental stability. They are recyclable, post-formable and can be joined by welding. The use of long/continuous fibre reinforced thermoplastic matrix composites involves, however, great technological and scientific challenges since thermoplastics present much higher viscosity than thermosettings, which makes much difficult and complex the impregnation of reinforcements and consolidation tasks. [1] In this work continuous fibres reinforced thermoplastic matrix towpregs were produced using equipment developed by the Institute for Polymers and Composites (IPC). The processing of the towpregs was made by pultrusion, in a developed prototype equipment existing in the Engineering School of the Polytechnic Institute of Porto (ISEP). Different thermoplastic matrices and fibres raw-materials were used in this study to manufacture pultruded composites for commercial applications (glass and carbon fibre/ polypropylene) and for advanced markets (carbon fibre/Primospire®). To improve the temperature distribution profile in heating die, different modifications were performed. In order to optimize both processes, towpregs production and pultruded composites profiles were analysed to determine the influence of the most relevant processing parameters in the final properties. The final pultruded composite profiles were submitted to mechanical tests to obtain the relevant properties
- 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.
- Analysis of the influence of cladding panels in the seismic behaviour of a prc industrial buildingPublication . Ostetto, Liana; Sousa, Romain; Rodrigues, Hugo; Fernandes, PauloRecent reports on the latest earthquakes in Italy and Turkey have highlighted some critical problems in the connections of cladding panels on industrial precast reinforced concrete (PRC) structures. The panel connections did not perform as expected, causing non-structural damages and, in most cases, leading to the panels overturning. The damage and collapse of these elements may result in significant losses of human lives and large socio-economic impacts due to business interruption. Despite being demonstrated that cladding panels can have a significant contribution on seismic response, these elements are often considered as non-structural, ignoring the interaction with the RC frame, and considering that they do not influence the seismic behaviour. Making use of a simplified macro element, this study assesses the seismic capacity of commonly employed claddings-to-structure connections, as well as the interaction of the cladding panels with the PRC industrial buildings. The analyses were carried out considering a PRC building representative of the Portuguese industrial park, studied with and without cladding panels. The seismic behaviour of the structure are assess considering both non-linear static and dynamic procedures.
- An Approach to Assess the Performance of Mobile Applications: A Case Study of Multiplatform Development FrameworksPublication . Mota, Dany; Martinho, RicardoComparative studies between software multiplatform development frameworks lack a proper approach that can be replicated in future performance assessments. Moreover, there is still a deficit in performance comparison tools. Also, performance comparisons realized between mobile applications developed under these multiplatform frameworks should be done with applications running in Release Mode, which ends up not happening in most studies. The objective of this paper is thus to create a whole comparative process as correct and stable as possible, so that we can use it to safely assess performance of mobile applications developed with these frameworks. As a case study, we compare the well-known Flutter and React Native frameworks, and present the obtained results under the proposed approach. With this work, developers can not only assess both these particular frameworks, but also use the approach for further comparisons.
- Architectural Challenges on the Integration of e-Commerce and ERP Systems: A Case StudyPublication . Santos, Fábio; Martinho, RicardoMany retail companies had to go online before their Enterprise Resource Planning (ERP)-type systems were ready to fulfill all business requirements. Their overall daily operation still heavily depends on these highly customized systems often mandatory because of legal obligations, which frequently come without e-commerce “off the shelf” integration. This paper identifies main challenges derived out of the architectural and integration requirements from a case study at an e-tailer company that operates via two sales channels: online store and third-party marketplaces. These challenges led to the definition of a system architecture and implementation considerations for this common integration scenario, which was validated through its implementation. Our proposed approach allows ERP-dependent organizations to start selling online with open-source technologies, avoiding extra ERP licensing and hidden maintenance costs.