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Publications

2017

Technologies for ageing in place to support the empowerment of patients with chronic diseases

Authors
Queirós, A; Pereira, L; Santos, M; Rocha, NP;

Publication
Advances in Intelligent Systems and Computing

Abstract
Objectives - This study aimed to identify: (i) the most relevant chronic diseases in terms of the application of technologies for ageing in place to promote the empowerment of patients; and (ii) types, outcomes and impacts of technologies for ageing in place being used to promote the empowerment of patients with chronic diseases. Methods - A systematic review of reviews and meta-analysis was performed based on a search of the literature. Results - A total of 34 reviews and meta-analysis across several chronic diseases were retrieved. These studies compare the empowerment of patients supported by different technologies with usual care. Conclusion - Technologies for ageing in place have positive effects on various health related outcomes, but further research is required to allow their incorporation in the clinical practice. © Springer International Publishing AG 2017.

2017

Multi-Robot Planning for Perception of Multiple Regions of Interest

Authors
Sousa Pereira, TRd; Mendes Moreira, APG; Veloso, MM;

Publication
ROBOT (1)

Abstract
In this paper we address the allocation of perception tasks among a set of multiple robots, for tasks such as inspection, surveillance, or search in structured environments. We consider a set of target regions of interest in a mapped environment that need to be sensed by any of the robots, and the problem is to find paths for the robots that cover all the target regions with minimal cost. We consider not only sensing range when determining paths for the robots to perceive the targets, but also a sensor cost function that can be adapted to each robot’s sensor. Thus the planning has to search for paths with minimal motion and perception cost, instead of the traditional approach where line-of-sight is the only requirement in a motion cost minimization problem. Our contribution is to use planning to determine possible perception positions for every robot, which we cluster and then use as possible waypoints that can be used to construct paths for all the robots. Given the combinatorial characteristics of path determination in this setting, we contribute a construction heuristic to find paths that guarantee full coverage of all the feasible perception target regions, while minimizing the overall cost. We assume robots are heterogeneous regarding their geometric properties, such as size and maximum perception range. We consider simulated scenarios where we show the benefits of our approach, enabling multi-robot path planning for perception of multiple regions of interest.

2017

Two-Tier Reactive Power and Voltage Control Strategy Based on ARMA Renewable Power Forecasting Models

Authors
Lu, JL; Wang, B; Ren, H; Zhao, DQ; Wang, F; Shafie khah, M; Catalao, JPS;

Publication
ENERGIES

Abstract
To address the static voltage stability issue and suppress the voltage fluctuation caused by the increasing integration of wind farms and solar photovoltaic (PV) power plants, a two-tier reactive power and voltage control strategy based on ARMA power forecasting models for wind and solar plants is proposed in this paper. Firstly, ARMA models are established to forecast the output of wind farms and solar PV plants. Secondly, the discrete equipment is pre-regulated based on the single-step prediction information from ARMA forecasting models according to the optimization result. Thirdly, a multi-objective optimization model is presented and solved by particle swarm optimization (PSO) according to the measured data and the proposed static voltage stability index. Finally, the IEEE14 bus system including a wind farm and solar PV plant is utilized to test the effectiveness of the proposed strategy. The results show that the proposed strategy can suppress voltage fluctuation and improve the static voltage stability under the condition of high penetration of renewables including wind and solar power.

2017

Data Mining in HIV-AIDS Surveillance System Application to Portuguese Data

Authors
Oliveira, A; Faria, BM; Rita Gaio, AR; Reis, LP;

Publication
JOURNAL OF MEDICAL SYSTEMS

Abstract
The Human Immunodeficiency Virus (HIV) is an infectious agent that attacks the immune system cells. Without a strong immune system, the body becomes very susceptible to serious life threatening opportunistic diseases. In spite of the great progresses on medication and prevention over the last years, HIV infection continues to be a major global public health issue, having claimed more than 36 million lives over the last 35 years since the recognition of the disease. Monitoring, through registries, of HIV-AIDS cases is vital to assess general health care needs and to support long-term health-policy control planning. Surveillance systems are therefore established in almost all developed countries. Typically, this is a complex system depending on several stakeholders, such as health care providers, the general population and laboratories, which challenges an efficient and effective reporting of diagnosed cases. One issue that often arises is the administrative delay in reports of diagnosed cases. This paper aims to identify the main factors influencing reporting delays of HIV-AIDS cases within the portuguese surveillance system. The used methodologies included multilayer artificial neural networks (MLP), naive bayesian classifiers (NB), support vector machines (SVM) and the k-nearest neighbor algorithm (KNN). The highest classification accuracy, precision and recall were obtained for MLP and the results suggested homogeneous administrative and clinical practices within the reporting process. Guidelines for reductions of the delays should therefore be developed nationwise and transversally to all stakeholders.

2017

Quantifying telescope phase discontinuities external to adaptive optics systems by use of phase diversity and focal plane sharpening

Authors
Lamb, MP; Correia, C; Sauvage, JF; Véran, JP; Andersen, DR; Vigan, A; Wizinowich, PL; van Dam, MA; Mugnier, L; Bond, C;

Publication
JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS

Abstract
We propose and apply two methods to estimate pupil plane phase discontinuities for two realistic scenarios on the very large telescope (VLT) and Keck. The methods use both phase diversity and a form of image sharpening. For the case of VLT, we simulate the "low wind effect" (LWE) that is responsible for focal plane errors in the spectro-polarimetric high contrast exoplanet research (SPHERE) system in low wind and good seeing conditions. We successfully estimate the simulated LWE using both methods and show that they are complimentary to one another. We also demonstrate that single image phase diversity (also known as phase retrieval with diversity) is also capable of estimating the simulated LWE when using the natural defocus on the SPHERE/differential tip tilt sensor (DTTS) imager. We demonstrate that phase diversity can estimate the LWE to within 30-nm root mean square wavefront error (RMS WFE), which is within the allowable tolerances to achieve a target SPHERE contrast of 10-6. Finally, we simulate 153-nm RMS of piston errors on the mirror segments of Keck and produce NIRC2 images subject to these effects. We show that a single, diverse image with 1.5 waves (peak-to-valley) of focus can be used to estimate this error to within 29-nm RMS WFE, and a perfect correction of our estimation would increase the Strehl ratio of an NIRC2 image by 12%.

2017

Ontologies for the Interoperability of Heterogeneous Multi-agent Systems in the Scope of Power and Energy Systems

Authors
Santos, G; Pinto, T; Vale, ZA;

Publication
PAAMS (Special Sessions)

Abstract
One of the main challenges in power & energy systems is the development of decision support tools which approach the problem as a whole. In this scope, this work contributes to the increase of the interoperability between heterogeneous agent based systems through the use of ontologies, enabling semantic communications.

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