4 resultados para Mobility and roaming
em Repositório Institucional da Universidade de Aveiro - Portugal
Resumo:
The purpose of this study is to understand, impact and evaluate the development of intercultural communicative competencies among European credit-seeking exchange students and other sojourners through purposeful intercultural pedagogy. This pedagogy encompasses intentional intercultural- educational approaches which aim to support and enhance sojourners’ intercultural learning throughout the study abroad cycle (pre-departure, in-country and reentry phases). To test and validate these pedagogies a 20-hour intervention was designed and implemented among two cohorts of 31 sojourners during the in-country phase of their sojourn in Portugal. The process to develop and validate the intercultural intervention was driven by a mixed-methods methodology which combined quantitative and qualitative data to triangulate, complement and expand research results from a pragmatic stance. The mixed methods research design adopted is multi-phased and encompasses a multi-case study and an evaluative component. The multi-case component is embodied by sojourner cohorts: (1) the primary case study involves 19 incoming students at the University of Aveiro (Portugal) as participants in the European exchange program Campus Europae; (2) the second case study comprises three incoming Erasmus students and nine highly skilled immigrants at the same university. All 31 sojourners attended two intermediate Portuguese as Foreign Language classrooms where the intervention was employed. Data collection was extensive and involved collecting, analyzing and mixing quantitative and qualitative strands across four research phases. These phases refer to the: (1) development, (2) implementation and (3) evaluation of the intervention, as well as to (4) a stakeholder analysis of the external value of the intervention and of the Campus Europae program. Data collection instruments included pre and posttest questionnaires and semi-structured interviews. Results confirm the intercultural effectiveness of the intervention and the positive impact upon research participants’ intercultural gains. This impact was, however, greater in case study 2. Among explanatory variables, three stand out: (1) participant meaning-making abilities, (2) host language proficiency and related variables, and (3) type of sojourn or exchange programs. Implications for further research highlight the need to systematize purposeful intercultural pedagogy in sojourner populations in general, and in European credit student mobility in particular. In the latter case, these pedagogies should be part of the design and delivery of credit-bearing exchange programs in pre- departure, in-country and re-entry phases. Implications for practice point to the urge to improve intercultural practices in: macro (higher education institutions), mezzo (exchange programs) and micro (sojourner language classrooms) contexts where this research took place, and wider social scenarios they represent.
Resumo:
In this paper, the authors, as teachers of the Virtual Mobility and Learning ERASMUS Intensive Programme (VML–IP), put forward an analysis of the student’s final evaluation of the Programme as to the most important competences they have developed. In terms of methodology, this study has an exploratory and descriptive nature; hence, being based on empiric evidence. Thus, in the last face-to-face session, students were asked by the Programme’s coordination to present an overall evaluation of their experience in the VML–IP. Data were collected in loco, i.e. through the posters created by each group, as well as the video of the students’ oral presentations. They were later analysed using content analysis as data analysis technique. The results unveil that, although the main goal was fulfilled – i.e. to be able to design and implement a course on a ‘Virtual Mobility and Learning’ topic underpinned by solid theoretical background in the area –, the fact is that every group also pointed out several soft competences as a very important part of their experiences, and crucial for their development as students and future professionals.
Resumo:
Nowadays, wireless communications systems demand for greater mobility and higher data rates. Moreover, the need for spectral efficiency requires the use of non-constant envelope modulation schemes. Hence, power amplifier designers have to build highly efficient, broadband and linear amplifiers. In order to fulfil these strict requirements, the practical Doherty amplifier seems to be the most promising technique. However, due to its complex operation, its nonlinear distortion generation mechanisms are not yet fully understood. Currently, only heuristic interpretations are being used to justify the observed phenomena. Therefore, the main objective of this work is to provide a model capable of describing the Doherty power amplifier nonlinear distortion generation mechanisms, allowing the optimization of its design according to linearity and efficiency criteria. Besides that, this approach will allow a bridge between two different worlds: power amplifier design and digital pre-distortion since the knowledge gathered from the Doherty operation will serve to select the most suitable pre-distortion models.
Resumo:
The last couple of decades have been the stage for the introduction of new telecommunication networks. It is expected that in the future all types of vehicles, such as cars, buses and trucks have the ability to intercommunicate and form a vehicular network. Vehicular networks display particularities when compared to other networks due to their continuous node mobility and their wide geographical dispersion, leading to a permanent network fragmentation. Therefore, the main challenges that this type of network entails relate to the intermittent connectivity and the long and variable delay in information delivery. To address the problems related to the intermittent connectivity, a new concept was introduced – Delay Tolerant Network (DTN). This architecture is built on a Store-Carry-and-Forward (SCF) mechanism in order to assure the delivery of information when there is no end-to-end path defined. Vehicular networks support a multiplicity of services, including the transportation of non-urgent information. Therefore, it is possible to conclude that the use of a DTN for the dissemination of non-urgent information is able to surpass the aforementioned challenges. The work developed focused on the use of DTNs for the dissemination of non-urgent information. This information is originated in the network service provider and should be available on mobile network terminals during a limited period of time. In order to do so, four different strategies were deployed: Random, Least Number of Hops First (LNHF), Local Rarest Bundle First (LRBF) e Local Rarest Generation First (LRGF). All of these strategies have a common goal: to disseminate content into the network in the shortest period of time and minimizing network congestion. This work also contemplates the analysis and implementation of techniques that reduce network congestion. The design, implementation and validation of the proposed strategies was divided into three stages. The first stage focused on creating a Matlab emulator for the fast implementation and strategy validation. This stage resulted in the four strategies that were afterwards implemented in the DTNs software Helix – developed in a partnership between Instituto de Telecomunicac¸˜oes (IT) and Veniam R , which are responsible for the largest operating vehicular network worldwide that is located in Oporto city. The strategies were later evaluated on an emulator that was built for the largescale testing of DTN. Both emulators account for vehicular mobility based on information previously collected from the real platform. Finally, the strategy that presented the best overall performance was tested on a real platform – in a lab environment – for concept and operability demonstration. It is possible to conclude that two of the implemented strategies (LRBF and LRGF) can be deployed in the real network and guarantee a significant delivery rate. The LRBF strategy has the best performance in terms of delivery. However, it needs to add a significant overhead to the network in order to work. In the future, tests of scalability should be conducted in a real environment in order to confirm the emulator results. The real implementation of the strategies should be accompanied by the introduction of new types of services for content distribution.