Abstract
The description of data is a central task in research data management. Describing datasets requires deep knowledge of both the data and the data creation process to ensure adequate capture of their meaning and context. Metadata schemas are usually followed in resource description to enforce comprehensiveness and interoperability, but they can be hard to understand and adopt by researchers. We propose to address data description using ontologies, which can evolve easily, express semantics at different granularity levels and be directly used in system development. Considering that existing ontologies are often hard to use in a cross domain research data management environment, we present an approach for creating lightweight ontologies to describe research data. We illustrate our process with two ontologies, and then use them as configuration parameters for Dendro, a software platform for research data management currently being developed at the University of Porto.

Abstract
Purpose: Low- and medium-technology sectors' (LMTs) role in modern economies has been overshadowed by the argument relating knowledge creation to R&D and thus to high-tech industries. Nevertheless, whereas a broader definition of innovation has enabled LMTs to emerge as innovative environments, a blind reliance on non-R&D-based indicators may be harmful too by neglecting LMTs' contribution to the development of cutting-edge, R&D-based knowledge. This paper aims to provide answers to the following questions: do LMTs innovate? Do they induce high-tech innovations across other sectors? Do networks have an impact on LMTs' innovation commitment? Can LMTs' innovation commitment be related to a better performance? Design/methodology/approach: The research method used in this work was based on a case study approach using in-depth face-to-face interviews with representatives from two footwear companies and one technology supplier. Findings: Collaboration with relevant stakeholders along the footwear value chain proved fundamental to the creation of innovation opportunities for all parties involved. Both footwear companies have embraced innovation strategies, allowing them to take over new functions along the value chain and build successful international paths. These strategies involved active participation in cutting-edge, high-tech knowledge prompting innovation at higher-tech companies too. Research limitations/implications: The paper fails to establish a clear causative relationship between companies' performance and their R&DI commitment. In addition, due to the number of companies involved in the study, the findings cannot be simply extrapolated to the whole Portuguese footwear sector. Originality/value: The paper highlights the commitment to innovation in a traditional sector and explores an underresearched topic - that of LMTs' involvement in R&D activities. © Emerald Group Publishing Limited.

Abstract
In this paper we address the problem of tracking multiple AUVs using acoustic signals. Using For this challenging scenario, we propose to use a Probability Hypothesis Density Filter and present a suitable implementation of the Sequential Monte Carlo PHD filter. It will be demonstrated that a particle filter implementation of the aforementioned filter can be used to successfully track multiple AUVs, changing in number over time, using range measurements from the vehicles to a set of acoustic beacons. Simulation results will be presented that allow to evaluate the performance of the filter.

Abstract
The current technological and social Era in which our society lives, provides for the necessary background in order for Social Networks Sites (SNS) to be considered an essential and very relevant tool not only for individual social interaction, but also for firms to perform business activities. By analyzing the existent literature on the SNS adoption at firm level, the authors perceived the existence of a knowledge gap on this topic, thus creating the need for a SNS related literature review. In this paper, we present a systematic literature review on the SNS topic, mainly focusing the efforts towards the adoption of this technology at firm level. Some final considerations on future research are also presented in the final section of the article.

Abstract
This article discusses the motion analysis based on dense optical flow fields and for a new generation of robotic moving systems with real-time constraints. It focuses on a surveillance scenario where an especially designed autonomous mobile robot uses a monocular camera for perceiving motion in the environment. The computational resources and the processing-time are two of the most critical aspects in robotics and therefore, two non-parametric techniques are proposed, namely, the Hybrid Hierarchical Optical Flow Segmentation and the Hybrid Density-Based Optical Flow Segmentation. Both methods are able to extract the moving objects by performing two consecutive operations: refining and collecting. During the refining phase, the flow field is decomposed in a set of clusters and based on descriptive motion properties. These properties are used in the collecting stage by a hierarchical or density-based scheme to merge the set of clusters that represent different motion models. In addition, a model selection method is introduced. This novel method analyzes the flow field and estimates the number of distinct moving objects using a Bayesian formulation. The research evaluates the performance achieved by the methods in a realistic surveillance situation. The experiments conducted proved that the proposed methods extract reliable motion information in real-time and without using specialized computers. Moreover, the resulting segmentation is less computationally demanding compared to other recent methods and therefore, they are suitable for most of the robotic or surveillance applications.

Abstract
A sincronização online de ginástica potencia novas possibilidades para melhorar o bem-estar físico e social das pessoas com restrições de deslocação. A nossa proposta passa pela criação de uma plataforma 3D - Online Gym - que permita que os utilizadores interajam e participem em sessões online de ginástica em grupo através do Microsoft Kinect. No presente artigo, com vista à concretização desta proposta, analisamos três alternativas tecnológicas para a implementação de serviços de deteção de movimentos que possam ser integrados em plataformas gráficas multiutilizador. Nos resultados, expõem-se as características de cada uma e o impacte respetivo para sua utilização na concretização desta proposta ou outras iniciativas similares.