2018
Autores
Dragoicea, M; Badr, NG; Cunha, JFE; Oltean, VE;
Publicação
EXPLORING SERVICE SCIENCE
Abstract
This paper describes an exploration process aligned with the core domain of Service Science inside a critical sector of Society, aiming at developing City in a sustainable, responsible, inclusive way. The paper focuses on defining the Public Safety as a Service concept in an inclusive and responsible value co-creation urban design vision for liveable cities. It explains how service intelligence can act on immaterial artefacts to transform data into information to generate value co-creation processes whose outcomes are applied to the evolution of knowledge in public safety services. Public safety is approached within a service ecosystem perspective, following the global targets of the Sendai Framework for Disaster Risk Reduction as an application perspective. Managerial implication are approached from two perspectives: establishment of governance principles with the help of Elinor Ostrom's works, and a Viable Systems Approach on the response to disasters operating rules.
2018
Autores
Sousa, R; Gama, J;
Publicação
33RD ANNUAL ACM SYMPOSIUM ON APPLIED COMPUTING
Abstract
This paper describes the development of a Co-training (semi-supervised approach) method that uses multiple learners for single target regression on data streams. The experimental evaluation was focused on the comparison between a realistic supervised scenario (all unlabelled examples are discarded) and scenarios where unlabelled examples are used to improve the regression model. Results present fair evidences of error measure reduction by using the proposed Co-training method. However, the error reduction still is relatively small.
2018
Autores
Mehrasa, M; Pouresmaeil, E; Pournazarian, B; Sepehr, A; Marzband, M; Catalao, JPS;
Publicação
ENERGIES
Abstract
This paper presents a synchronous resonant control strategy based on the inherent characteristics of permanent magnet synchronous generators (PMSG) for the control of power converters to provide stable operating conditions for the power grid under high penetration of renewable energy resources (RERs). The proposed control technique is based on the small signal linearization of a dynamic model with grid specifications, load-current-based voltages, and power converter currents. A combination of the linearized dynamic model with the PMSG swing equation and resonant controller leads to a control technique with synchronous features and appropriate inertia for the control of converter-based power generators. As the main contribution of this work, an extra functionality is proposed in the control loop of the proposed model to solve the inherent inconveniences of conventional synchronous generators. Also, a comprehensive collaboration between interfaced converter specifications and PMSG features is achieved as another contribution of the proposed control technique, and this can guarantee accurate performance under various conditions. A current perturbation curve is introduced to assess the variations of the grid frequency and voltage magnitude under operation of the interfaced converters controlled by the proposed control technique. Moreover, by taking into account the load-based voltages, the effects of the current perturbation components are investigated. The proposed model is simulated in MATLAB/Simulink environment to verify the high performance of the proposed control technique over the other existing control methods.
2018
Autores
Khanal, SR; Reis, A; Barroso, J; Filipe, V;
Publicação
Trends and Advances in Information Systems and Technologies - Volume 2 [WorldCIST'18, Naples, Italy, March 27-29, 2018]
Abstract
In the later stages of the aging process, an elderly person might need the help of a family member or a caregiver. Technology can be used to help to take care of elderly persons. Autonomous systems, using special interfaces, can collect information from elderly people, which might be useful to predict and recognize health related problems or physical security problems in real time. The emerging technology of image processing, in particular, the emotion recognition, can be a good option to use in elderly care support systems. In this article, we implemented a Microsoft Azure – Emotion SDK to recognize emotion of elderly that able to detect faces and recognize emotions in real time and to be used for elderly care support. The analysis is done with an online video stream, which analyzes facial expression, so that in case of a critical emotion, e.g., if an elderly is very sad or crying, it will inform a caregiver or related entity. From the experiment, we concluded that emotion recognition is a reliable technology to be implemented in real time elderly care. © Springer International Publishing AG, part of Springer Nature 2018.
2018
Autores
Melo, T; Mendonça, AM; Campilho, A;
Publicação
Image Analysis and Recognition - 15th International Conference, ICIAR 2018, Póvoa de Varzim, Portugal, June 27-29, 2018, Proceedings
Abstract
The creation of retinal mosaics from sets of fundus photographs can significantly reduce the time spent on the diabetic retinopathy (DR) screening, because through mosaic analysis the ophthalmologists can examine several portions of the eye at a single glance and, consequently, detect and grade DR more easily. Like most of the methods described in the literature, this methodology includes two main steps: image registration and image blending. In the registration step, relevant keypoints are detected on all images, the transformation matrices are estimated based on the correspondences between those keypoints and the images are reprojected into the same coordinate system. However, the main contributions of this work are in the blending step. In order to combine the overlapping images, a color compensation is applied to those images and a distance-based map of weights is computed for each one. The methodology is applied to two different datasets and the mosaics obtained for one of them are visually compared with the results of two state-of-the-art methods. The mosaics obtained with our method present good quality and they can be used for DR grading. © 2018, Springer International Publishing AG, part of Springer Nature.
2018
Autores
Hashemipour, N; Niknam, T; Aghaei, J; Farahmand, H; Korpas, M; Shafie khah, M; Osorio, GJ; Catalao, JPS;
Publicação
2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)
Abstract
Uncontrolled operation of distributed generation (DG) can cause interference with the operation of other equipment such as tap-changers, and non-optimal use of their capability. Thus, having an appropriate scheduling and control on DGs is a crucial issue for distribution system operators. In this paper, a linear multi-objective model for power distribution system scheduling that coordinates tap-changers, photovoltaics (PVs) and battery energy storage operation is proposed. Accordingly, tap-changers experience lower stress, batteries' state of charge is kept in suitable range and DGs are used more effectively. The objective functions of the proposed model encompass improving voltage profile, minimizing losses and peak load. Epsilon-constraint method is employed for solving the multi-objective problem, generating the Pareto set. A new decision-making method is proposed to select the preferred solution from the Pareto set. The 33-bus IEEE test system is used to test the performance of the model. Conclusions are duly drawn.
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