10 research outputs found

    Desenvolvimento de um sistema de controlo e monitorização residencial através de tecnologias associadas à Internet das Coisas

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    Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e ComputadoresA presente dissertação visa o desenvolvimento de um sistema de controlo e monitorização residencial baseado numa plataforma IoT (Internet of Things). O sistema assenta numa arquitetura de redes sem fios híbrida que integra vários dispositivos Bluetooth Low Energy (BLE) e/ou Wi-Fi com diferentes funções, como nós sensores, nós atuadores e um hub/gateway. A comunicação entre entidades da plataforma é assegurada pelo protocolo MQTT (Message Queuing Telemetry Transport) através do modelo publish/subscribe. A realização deste projeto assenta em vários aspetos essenciais, dos quais se destacam: especificação da arquitetura enquadrada com as necessidades e funcionalidades desejadas; seleção e programação de dispositivos para controlo e monitorização de equipamentos da smart home; implementação de base de dados local para o armazenamento de dados relevantes; implementação de gateway (BLE-Wi-Fi) de forma a permitir a comunicação entres dispositivos com diferentes protocolos; desenvolvimento de aplicação Android para controlar e monitorizar em tempo real os equipamentos através de uma interface gráfica. Para a validação experimental foram realizados diversos testes para verificar o atraso e a fiabilidade das comunicações num ambiente habitacional. Foi possível verificar que não ocorreram perdas de pacotes e que o atraso máximo em todos os casos foi inferior a 1 segundo, permitindo que o sistema reaja rapidamente a alterações do valor de corrente, evitando que o disjuntor na habitação atue e possibilitando que o utilizador receba/envie dados de forma quase instantânea. A aplicação Android desenvolvida funcionou como pretendido, enviando e recebendo dados através da rede com o protocolo MQTT, e os sensores utilizados funcionaram com a precisão adequada. Um sistema de carregamento de veículos elétricos já existente foi integrado com sucesso no sistema e foi desenvolvido um protótipo de uma tomada elétrica inteligente que calcula os valores eficazes de tensão e corrente e controla o estado de operação do equipamento que a ela estiver ligado. O desenvolvimento do sistema teve em conta a utilização de software/firmware de utilização livre e hardware de baixo custo. Conforme validado com os resultados experimentais, os objetivos estabelecidos inicialmente foram cumpridos.This dissertation aims the development of a home control and monitoring system based on an IoT (Internet of Things) platform. The system is based on a hybrid wireless architecture that integrates multiple Bluetooth Low Energy (BLE) and/or Wi-Fi devices with different functions such as sensor nodes, actuator nodes and a hub/gateway. Communication between platform entities is ensured by the MQTT (Message Queuing Telemetry Transport) protocol through the publish/subscribe model. For the realization of this project it was essential: to specify an architecture that met the needs and desired functionality; select and program devices to efficiently control and monitor smart home equipment; implement a local database for storing relevant data; implement a gateway (BLE-Wi-Fi) to allow communication between devices with different protocols; and develop an Android application to control and monitor equipment in real time through a graphical interface. Experimental tests were performed to verify the delay and reliability of communications in a residential environment. No packet loss occurred and the maximum delay in all cases was less than 1 second, allowing the system to react quickly to changes in current value, preventing the circuit breaker in the home from tripping and allowing the user to receive/send data in a timely manner. The Android application worked as intended by sending and receiving data over the network using the MQTT protocol and the sensors worked with the proper accuracy. An existing electric vehicle charging system has been successfully integrated into the system and a prototype smart electrical socket has been developed to measure the current and voltage and control the operating state of the connected equipment (ON/OFF). The development of the system considered the use of free software/firmware and low-cost hardware. As validated with the experimental results, the initially established objectives were met, allowing even new approaches

    Development and evaluation of smart home IoT systems applied to HVAC monitoring and control

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    This work describes the development and evaluation of two smart home-based Internet of Things (IoT) systems applied to HVAC (Heating, Ventilation and Air Conditioning) monitoring and control, including parameters such as temperature, humidity, air quality, smoke detection, and human presence. These systems are based on a flexible hybrid wireless network architecture combining Bluetooth Low Energy (BLE) and IEEE 802.11/Wi-Fi, in order to adapt to the requirements of different types of sensor and actuator devices. The original implemented network is based on Cypress PSoC 4 BLE boards and HyperText Transfer Protocol (HTTP), whereas the new network uses ESP32 boards and includes Message Queue Telemetry Transport (MQTT), a lightweight messaging protocol suitable for IoT devices which provides additional quality of service (QoS) mechanisms to guarantee the delivery of messages. A smart temperature control system was implemented in the BLE/Wi-Fi gateway (Raspberry Pi) to keep the room temperature inside a user-defined range. An online database was also developed using the Amazon Web Services (AWS) cloud platform, allowing the users to access the HVAC data and control the system parameters, through the Internet, using a mobile app developed for Android devices. Experimental tests were performed to validate the functionalities and performance of the developed systems. The obtained results demonstrate that the new network provides lower delay values compared with the original implementation.This work was supported by FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020

    Efficiency comparison of different DC-DC converter architectures for a power supply of a LiDAR system

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    LiDAR (Light Detection And Ranging) is a technology used to meas-ure distances to objects. Internally, a LiDAR system is constituted by several components, including a power supply, which is responsible to provide the dis-tinct voltage levels necessary for all the components. In this context, this paper presents an efficiency comparison of three different DC-DC converter architec-tures for a LiDAR system, each one composed of three DC-DC converters: in parallel; in cascade; and hybrid (mix of parallel and cascade). The topology of the adopted integrated DC-DC converters is the synchronous buck Switched-Mode Power Supply (SMPS), which is a modified version of the basic buck SMPS topology. Three distinct SMPSs were considered: LM5146-Q1, LM5116, and TPS548A20RVER. These SMPSs were selected according to the require-ments of voltage levels, namely, 12 V, 5 V, and 3.3 V. Along the paper, the prin-ciple of operation of the SMPSs is presented, as well as the evaluation results obtained for different operating powers, allowing to establish a comprehensive efficiency comparison.This work has been supported by national funds through FCT—Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020, and also European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 037902; Funding Reference: POCI-01-0247-FEDER-037902]

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Characterisation of microbial attack on archaeological bone

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    As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

    Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study (Intensive Care Medicine, (2021), 47, 2, (160-169), 10.1007/s00134-020-06234-9)

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    The original version of this article unfortunately contained a mistake. The members of the ESICM Trials Group Collaborators were not shown in the article but only in the ESM. The full list of collaborators is shown below. The original article has been corrected
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