Abstract
Monitor, control and process data on top of distributed networks has been a trending topic in the past few years, with ubiquity being adjective to computing and, gradually, the Internet of Things becoming a reality in home and factory automation or Ambient Assisted Living (aal). Still, there is a general lack of knowledge and best practices on how to build systems that integrate devices and services from third-parties which connect dynamically with each other. Recurring problems such as security, clustering, message passing, deployment and other orchestration details also lack a standardized solution. The authors describe a platform that simplifies the bootstrap and maintenance of such complex systems, presenting its application in an aal scenario. Such platform could orchestrate most distributed systems, possibly setting a pattern for distributed ubiquitous computing. © 2013 Springer-Verlag Berlin Heidelberg.

Abstract
Virtual Environments (VE) systems may provide a new way to deliver information and services in many areas, for example in tourism, urban planning and education. In urban VE there is a close link between the virtual environment and the urban environment that are intended to represent. These VE can be an intuitive way to access a set of services with a direct association to the real object or entity to which they are related. In this article, we describe a case study that aimed at exploring the possibility of using new interfaces to exploit and use services in urban VE with a greater sense of immersiveness. The results indicate that the VE interfaces are a natural and intuitive access to digital services. While users have felt a greater difficulty in performing some of the tasks in immersive scenario, the majority considered that this scenario provided a greater sense of immersion and realism.

Abstract
Image quality assessment as perceived by humans is of crucial importance in numerous fields of image processing. Transmission and storage of digital media require efficient methods to reduce the large number of bits to store an image, while maintaining sufficiently high quality compared to the original image. Since subjective evaluations cannot be performed in various scenarios, it is necessary to have objective metrics that predict image quality consistent with human perception. However, objective metrics that considers high levels of the human visual system are still limited. In this paper, we investigate the possibility of automatically predict, based on saliency maps, the minimum image quality threshold from which humans can perceive the elements on a compressed image. We conducted a series of experimental subjective tests where human observers have been exposed to compressed images with decreasing compression rates. To measure the difference between the saliency maps of the compressed and the original image it was used the normalized absolute error metric. Our results indicate that the elements on the image are only perceived by most of the human subjects not at a specific compressed image quality level, but depending on a saliency map difference threshold.

Abstract

Abstract
Falling is a very serious problem for our society, as it affects one out of three older adults. Currently, this is a well-known problem and therefore multiple ICT-based solutions for falls management exist. In addition, a small part of them are said to help preventing falls, but most of the reviewed solutions doesn't seem to have their focus in reducing specific fall risk factors like loss of muscle mass or a poor balance. The proposed ICT-based fall prevention solution is based on an existing fall prevention exercise programme specifically designed for the Portuguese population. It takes advantage of the smartphone processing capabilities as well as its built-in inertial sensors to evaluate the movements performed during the execution of specific exercises. Using only a simple smartphone it is possible to provide a friendly and inexpensive solution capable of increasing seniors' adherence to fall prevention exercises as well as raise their motivation to properly execute the exercises in their home environment. © 2013 IEEE.

Abstract
O crescimento da Web trouxe vários problemas aos utilizadores. A grande quantidade de informação existente hoje em dia em alguns sítios Web torna a procura de informação útil muito difícil. Os objetivos dos proprietários dos sítios Web e dos utilizadores nem sempre coincidem. O conhecimento dos padrões de visitas dos utilizadores é crucial para que os proprietários possam transformar e adaptar o sítio Web. Este é o princípio do sítio Web adaptativo: o sítio Web adapta-se de forma a melhorar a experiência do utilizador. Alguns algoritmos foram propostos para adaptar um sítio da Web. Neste artigo, descrevemos uma proposta de um sistema de recomendação Web baseado em agentes que combina dois algoritmos: regras de associação e filtragem colaborativa. Ambos os algoritmos são incrementais e funcionam com dados binários. Os resultados mostram que, em algumas situações, a abordagem multiagente melhora a capacidade preditiva quando comparada com os agentes individuais.;
The growth of the Web has brought several problems for users. Today the vast amount of information on some web sites makes useful information finding very difficult. The objectives of the owners of the web sites and users do not always coincide. The knowledge of patterns of user visits is crucial to the owners to transform and adapt their web site. This is the adaptive website principle: the website adapts to improve the user experience. Some algorithms have been proposed to tailor a website. In this paper, we describe a proposal for a web recommendation system based on agents that combines two algorithms: association rules and collaborative filtering. Both algorithms are incremental and work with binary data. The results show that, in some situations, the multi-agent approach overcomes the predictive capacity of individual agents.