Abstract

Abstract
This paper focuses on the combination of 360-degree video and virtual reality for improving the touristic experience. Three scenarios were considered in this study: two 360-degree video visualizations, each one related to different touristic places, both presented in an immersive way, followed by an actual visit to those places. By comparing these situations, it was intended to determine the degree of perceived similarity between the virtual and the corresponding real sites, and to analyze if the users' expectancy was fulfilled. This research comprised a qualitative analysis using data collection based on questionnaires, which were applied to a sample consisted of 45 participants. The independent variables of the study were the participants' age and level of education. The results show no statistically significant impact between the two independent variables (users' age and level of education) and perceived similarity and users' expectancy. Our findings suggest that virtual tourism can act as an efficient promotion tool, considering that users' perceived destination image is not compromised regarding their age or level of education.

Abstract
In this paper, a game interface for children with learning difficulties designed to enable learning and training the interaction with a QWERTY keyboard, therefore enhancing digital literacy and inclusion, is presented. Specifically, the interface presented writing activities with several difficulty levels, from monosyllabic to polysyllabic words, allowing the training with the QWERTY Keyboard. To assess usability of the interface we performed a preliminary user test with ten children with learning disabilities and it was register the following usability variables: efficiency, effectiveness and satisfaction. The main results showed that children improved their performance with the keyboard throughout the activities but showed spelling difficulties in higher difficulty levels. These difficulties were not in interaction with the QWERTY keyboard but in the word spelling. Still, all conclude tasks with success, no one dropout.

Abstract
O ensino e aprendizagem da programação de computadores em ambiente e-learning constitui uma área que tem vindo a atrair um interesse crescente tanto por parte das universidades de ensino em rede como pelos investigadores do e-learning. Aprender a programar computadores requer o desenvolvimento de raciocínio lógico da parte do estudante, enquanto aprende a dominar as potencialidades de uma determinada linguagem de programação, a construir estruturas de dados e a desenvolver uma estratégia de resolução de problemas pela sua divisão e modularização em problemas mais simples de mais fácil conquista. Adicionalmente importa que o estudante desenvolva competências de trabalho em grupo, de estudo individual com elevados níveis de concentração para realizar trabalho de revisão e depuração de código fonte. O ensino on-line de programação de computadores é constituído por estes aspetos, exigindo um elevado grau de interação entre estudantes e destes com o professor. Neste artigo, apresentamos um conjunto de reflexões e propostas concretas de estratégias de implementação do ensino e aprendizagem da programação de computadores, de nível universitário, explorando o método de “design” de instruções como uma abordagem do diálogo, uma adaptação da taxonomia de Bloom, com base na experiência e no modelo pedagógico virtual da Universidade Aberta de Portugal.

Abstract
The design, development and deployment of autonomous sustainable ocean platforms for exploration and monitoring can provide researchers and decision makers with valuable data, trends and insights into the largest ecosystem on Earth. Although these outcomes can be used to prevent, identify and minimise problems, as well as to drive multiple market sectors, the design and development of such platforms remains an open challenge. In particular, energy efficiency, control and robustness are major concerns with implications for autonomy and sustainability. Rigid wingsails allow autonomous boats to navigate with increased autonomy due to lower power consumption and increased robustness as a result of mechanically simpler control compared to traditional sails. These platforms are currently the subject of deep interest, but several important research problems remain open. In order to foster dissemination and identify future trends, this paper presents a survey of the latest developments in the field of rigid wing sailboats, describing the main academic and commercial solutions both in terms of hardware and software.

Abstract
The paper deals with a robust constrained control based on extended state observer (ESO) and state controller design using integral plant models of step-wise increasing complexity. The presented approach is used to enforce and consolidate the student's skills by repeating the state observer and state controller design for several modifications of the plant model. Importance of the control design evaluation by appropriate performance measures is also stressed. Thereby, this approach may help in discovering new interesting properties of this type of control.