2021
Authors
Faria C.L.; Martins M.S.; Lima R.; Matos T.; Miranda J.M.; Goncalves L.M.;
Publication
Oceans Conference Record IEEE
Abstract
The present work shows the development of a linear electromagnetic generator (LEG) for applications in marine and fluvial sensors. The LEG was submitted to tests with small oscillating frequencies of 0.1-0.4 Hz, and the output power obtained for these frequencies has allowed to supply energy to at least 6 sensors with a total consumed power of 5.76mW or to charge the batteries when the sensors are in a sleep mode. As a result, it is possible to extend the operation time and reduce the logistic costs for sea or river sensors applications, by using the proposed micro underwater generator.
2021
Authors
Oliveira, A; Leitão, A; Carvalho, L; Dias, L; Guimarães, L; Ribeiro, M;
Publication
IET Conference Proceedings
Abstract
Distribution lines are one of the most critical assets in distribution networks. In fact, overhead lines and subterranean cables are subjected to numerous internal and external factors that can cause failures and degradation over time. To prevent customer disconnection and to ensure continuous electricity delivery, the Distribution System Operator (DSO) strives to minimize the number of distribution line failures by carrying out inspection and preventive maintenance actions. Typically, HV and MV networks cover wide areas of the territory and comprise many lines of different types (overhead & subterranean) and equipment (e.g. conductor, isolator, poles), which makes it difficult to predict when failures will occur, which distribution line will fail and its location. The latter information is especially relevant since some distribution lines can cover a considerable distance. Motivated by a real-world application, this work presents a methodology to predict and locate future HV and MV distribution line failures. The methodology encompasses clustering techniques to group lines sharing similar characteristics, identifying the most relevant factors on the lines' degradation. In addition, historical records are leveraged by a prediction algorithm to estimate the number of failures and the failed section of the line. The approach was validated using data from the Portuguese HV and MV DSO (E-Redes). The results highlight the advantages of the proposed method compared with benchmark approaches. © 2021 The Institution of Engineering and Technology.
2021
Authors
Mehrjerdi, H; Hemmati, R; Shafie khah, M; Catalao, JPS;
Publication
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
Abstract
This article proposes a unified solution to address the energy issues in net-zero energy building (ZEB), as a new contribution to earlier studies. The multicarrier energy system, including hydro-wind-solar-hydrogen-methane-carbon dioxide-thermal energies is integrated and modeled in ZEB. The electrical sector is supplied by hydro-wind-solar, combined heat and power (CHP), and pumped hydro storage (PHS). The thermal sector is supplied by CHP, thermal boiler, and electric heating. The hydrogen storage system and Methanation process operate as the interface energy carriers between the electrical and thermal sectors. The carbon dioxide (CO2) of the ZEB is captured and fed into the Methanation process. The purpose is minimizing the released CO2 to the atmosphere while all the electrical-thermal load demands are successfully supplied considering events and disruptions. The model improves simultaneously the energy resilience and minimizes the environmental pollutions. The results demonstrate that the developed model reduces the CO2 pollution by about 33 451 kg per year. The model is a resilient energy system that can handle all failures of components. The model can efficiently handle 26% increment in the electrical loads and 110% increment in the thermal loads.
2021
Authors
Almeida, F;
Publication
Journal of Management and Business Education
Abstract
2021
Authors
Brito, C; Pinto, L; Marinho, V; Paiva, S; Pinto, P;
Publication
PROCEEDINGS OF 2021 16TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI'2021)
Abstract
The Implanted Medical Devices (IMD) industry has grown over the past few decades and is expected to grow in the coming ones. Being an asset for the health and quality of life of a patient, the availability of IMD-related products, their increasing complexity and advances in communication capabilities do not seem to have been seamlessly accompanied by cybersecurity concerns. Recent IMD can be integrated in the concept of IoT (Internet of Things) and thus, they are also exposed to attacks impacting on privacy and, above all, on the health and even the life of the device users. While in an early stage of the IMD development, the security procedures were based on the existing classic protocols and models and their functional capabilities were the focus of development, recent efforts have been made to address security from the start. In this paper we review the most recent contributions on the cybersecurity of IMD products and we highlight innovative ideas that represent new design and development paradigms of these devices next generations. In this review it is reinforced that the technological evolution and the progressive access of attackers to resources capable of exploiting multiple vulnerabilities can have a crucial impact in the IMD already implanted in the patient's body, designed to remain in operation for many years. Also, it brings the need to develop novel and robust protocols to guarantee security compatible with constrained computing resources and extremely low energy requirements to be feasible. Finally, the security and privacy concerns regarding this kind of devices should be addressed in the design phase and policies must move from damage mitigation to threat prevention.
2021
Authors
Bacelar Silva, GM; Cox, JF; Baptista, HR; Rodrigues, PP;
Publication
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
Abstract
The emergency department (ED) crowding is a critical healthcare issue worldwide that leads to long waits and poorer healthcare outcomes. Goldratt's theory of constraints (TOC) has been used effectively to improve such problematic environments for more than three decades. While most TOC solutions are simple, with many viewing them as purely common sense, they represent paradigm shifts in how to manage complex, uncertain, and silo environments. Goldratt used a simple dice game with a straight flow (I-shape) to illustrate the impact of dependent resources and statistical fluctuations in managing resources. Additionally, games help to overcome resistance to change and gain ownership by having participants develop their solutions. This new cooperative game illustrates an ED environment where patients may follow different care pathways according to their clinical needs, timeliness of care is measured in minutes, the demand is highly uncertain, and treatment must frequently start almost immediately. A Monte Carlo simulation validated the TOC solution to this ED game, achieving results similar to the real TOC's implementations. Moreover, this article provides a thorough process to Socratically introduce TOC to healthcare professionals and others to recognize that the EDs' (like other healthcare systems') core problem is the traditional approach to managing them.
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