Abstract
The rise of the Internet of Things and the growth of the IP cameras market are making Wireless Video Sensor Networks (WVSNs) popular. In turn, Wi-Fi is becoming the enabling technology for WVSNs due to its flexibility, high bitrates provided and low cost; however, these networks suffer from three major problems: bad performance, throughput unfairness, and energy inefficiency. In order to address the lack of holistic solutions to solve these problems, we propose the FM-WiFIX+ solution. This solution uses FM radio as an out-of-band control channel to signal when a video sensor should turn its IEEE 802.11 interface OFF, thus saving energy. The results obtained with a proof-of-concept prototype show that for a network with 7 nodes the proposed solution can achieve gains of energy up to 48 %, while maintaining good levels of performance and throughput fairness.

Abstract
In the last three decades with the Information Technologies advent and the growth of the concept of Virtual Environments, a set of new ways to perform tasks have emerged, in the most diversified areas of society. The main focus of this work was to verify if it was possible to increase the sense of presence through multi-sensory stimulation, creating a virtual environment of simulation that causes stress in exposure therapy, in this case in people who have a fear of heights. The evaluation of the sense of presence was made using the Portuguese version of a previously validated IPQ (Igroup Presence Questionnaire) and also through direct observation of the movements caused by oculomotor reflexes. Although the achievement results that were not very significant between the two tested groups, the multisensory simulation environment obtained better results in terms of involvement in relation to space and realism, which increased concentration in the experience. The obtained results seem to indicate that the alone addition of further stimuli does not lead to an increased feeling of presence, therefore existing the need to understand which are the critical stimuli for each assessment situation.

Abstract
Any computing system can be described as executing sequences of actions, with an action being any relevant change in the state of the system. For example, reading a file to memory, modifying the contents of the file in memory, or writing the new contents to the file are relevant actions for a text editor. In a distributed system, actions execute in multiple locations; in this context, actions are often called events. Examples of events in distributed systems include sending or receiving messages, or changing some state in a node. Not all events are related, but some events can cause and influence how other, later events occur. For example, a reply to a received mail message is influenced by that message, and maybe by prior messages received.

Abstract

Abstract
This work demonstrates the viability of using a cavity ring-down technique (CRD) for remote sensing. A conventional CRD configuration is used where and optical circulator is added inside the fibre loop to couple 20 km of optical fibre with a gold mirror at its end with the purpose of remote sensing. As a proof-of-concept, an intensity sensor based on an eight-figure configuration is used at the end of the 20 km of fibre for displacement sensing. In this case, a commercial OTDR is used as modulated light source to send impulses down to the fibre ring.

Abstract
Currently, a learning management system (LMS) plays a central role in any e-learning environment. These environments include systems to handle the pedagogic aspects of the teaching-learning process (e.g. specialized tutors, simulation games) and the academic aspects (e.g. academic management systems). Thus, the potential for interoperability is an important, although over looked, aspect of an LMS. In this paper, we make a comparative study of the interoperability level of the most relevant LMS. We start by defining an application and a specification model. For the application model, we create a basic application that acts as a tool provider for LMS integration. The specification model acts as the API that the LMS should implement to communicate with the tool provider. Based on researches, we select the Learning Tools Interoperability (LTI) from IMS. Finally, we compare the LMS interoperability level defined as the effort made to integrate the application on the study LMS.