Dynamic Thresholds for a Reliable Diagnosis of Switched Systems

Safety, availability and reliability are the main concern of many industries. Thus, fault detection and isolation of industrial machines, which are in most cases switched systems, is a primary task in many companies. The presented paper proposes a new diagnostic approach for switched systems using two powerful tools: bond graph and observer. A diagnostic layer detects model errors using bond graph, and a smart algorithm identifies and locates faults using observer. Although observers serve as fault detectors, they also have their own errors caused by convergence delay of calculations; even in the case of no sensor defect, the residue does not converge to zero. In this paper, we propose a new method to solve this problem by integrating dynamic thresholds in the detection procedure, which helped to avoid false alarms and ensure a highly reliable diagnosis.

Evaluation of a new user-centric sensor-based lighting control approach for circulation areas

Suitable lighting control strategies are essential for energy efficiency in buildings. Occupancy sensors are highly promoted by the building codes as one of the most cost-effective solutions in the sector. However, widespread use of these systems is still limited due to lack of user satisfaction. In this study, it is hypothesized that the “conventional use” of occupancy sensors (where user steps inside a dark area, and only afterwards the area becomes lit) is the reason behind the dissatisfaction. To overcome this problem, a new user-centric sensor-based lighting control approach is proposed in this study where users walk into an already lit area. An experiment was carried out in the circulation areas of a university building to test the feasibility of the proposed scenarios along with a conventional occupancy sensor scenario and the existing “no sensor” scenario. The main results revealed that the conventional use of occupancy sensors was not favoured by the participants in circulation areas while use of the proposed user-centric approach was as favourable as the existing constantly lit situation. It is the claim of this study that both energy efficiency and user satisfaction can be provided by the use of user-centric control systems.

Manejo autônomo da irrigação do tomateiro utilizando sensores Irrigás® de solo

O objetivo deste estudo foi avaliar e validar o uso do sensor Irrigas® de solo no manejo autônomo da irrigação do tomateiro, na região de Caçador, SC. Na safra 2016/17 foi conduzido um experimento em ambiente protegido avaliando cinco tensões de umidade do solo (20, 30, 40, 50 e 60 kPa) para o início da irrigação. Na safra 2017/18 foi conduzido um experimento a campo avaliando três manejos da irrigação (manejo autônomo da irrigação baseado nos sensores Irrigás®; manejo da irrigação baseado na tensiometria convencional; e manejo da irrigação sem critério técnico). Na safra 2018/19 foram avaliados os mesmos manejos da irrigação da safra anterior, com exceção do manejo da irrigação sem critério técnico. Por fim, na safra 2019/2020 foi conduzida uma unidade de validação em ambiente protegido avaliando o manejo autônomo da irrigação do tomateiro baseado no sensor Irrigás®. Na safra 2016/17 a maior produção de frutos comercializáveis (10,9 kg planta-1) foi obtida na tensão de umidade do solo estimada de 44 kPa. Na safra 2017/18 não houve diferenças entre os manejos de irrigação avaliados. Já na safra 2018/19 o manejo da irrigação baseado no sensor Irrigás® obteve produtividade de frutos comercializáveis 18% superior ao manejo baseado na tensiometria convencional. Os sensores Irrigás® permitiram o manejo autônomo da irrigação do tomateiro cultivado em ambiente protegido durante todo o ciclo.

Laser-Based, Optical, and Traditional Diagnostics of NO and Temperature in 400 kW Pilot-Scale Furnace

A fast sensor for simultaneous high temperature (above 800 K) diagnostics of nitrogen oxide (NO) concentration and gas temperature (T) based on the spectral fitting of low-resolution NO UV absorption near 226 nm was applied in pilot-scale LKAB’s Experimental Combustion Furnace (ECF). The experiments were performed in plasma and/or fuel preheated air at temperatures up to 1550 K, which is about 200 K higher than the maximal temperature used for the validation of the developed UV NO sensor previously. The UV absorption NO and T measurements are compared with NO probe and temperature measurements via suction pyrometry and tuneable diode laser absorption (TDL) using H2O transitions at 1398 nm, respectively. The agreement between the NO UV and NO probe measurements was better than 15%. There is also a good agreement between the temperatures obtained using laser-based, optical, and suction pyrometer measurements. Comparison of the TDL H2O measurements with the calculated H2O concentrations demonstrated an excellent agreement and confirms the accuracy of TDL H2O measurements (better than 10%). The ability of the optical and laser techniques to resolve various variations in the process parameters is demonstrated.

The accuracy and precision of interface pressure measuring devices: A systematic review

Introduction Interface pressure measuring devices are used to assess the pressures exerted by compression. Their performance, however, has not been considered as a contributing factor to reported inconsistences in the application of compression. A systematic review was undertaken to investigate the performance of commercially available devices used to measure interface pressure. Methods Six databases were searched identifying 17 devices, grouped into five sensor categories. Results A range of methodologies assessed the devices’ accuracy and precision, including method of pressure application, device calibration and type of surface used. No sensor category outperformed the others, however some individual sensors showed higher accuracy and/or precision compared to others. Two major factors influenced the performance of a number of sensors: the amount of applied pressure and the calibration method used. Conclusion Inconsistences in the application of compression may reflect, in part, issues related to accuracy and precision of the devices used to assess compression.

Glycemic Outcome Associated With Insulin Pump and Glucose Sensor Use in Children and Adolescents With Type 1 Diabetes. Data From the International Pediatric Registry SWEET

OBJECTIVE <p>This study aims to examine insulin delivery methods, glucose monitoring modalities and related outcomes in a large, international, diverse cohort of children and adolescents with type 1 diabetes from the SWEET-Registry</p> <p> </p> <p>RESEARCH DESIGN AND METHODS</p> <p>Participants with type 1 diabetes of <u>></u>1 year of duration, aged ≤18y and documented pump/sensor usage during the period August 2017-July 2019 were stratified into four categories: injections-no sensor (reference); injections+sensor; pump-no sensor; pump+sensor. HbA_1c and proportion of patients with DKA or SH were analyzed; linear and logistic regression models adjusted for demographics, region and gross-domestic-product (GDP)-per capita were applied.</p> <p> </p> <p>RESULTS</p> <p>Data of 25,654 subjects were analyzed. Injections-no sensor: 37.44% [adjusted-HbA_1c 8.72 (95%CI 8.68-8.75)]; injections+sensor: 14.98% [adjusted-HbA_1c 8.30 (8.25-8.35)]; pump-no sensor: 17.22% [adjusted-HbA_1c 8.07 (8.03-8.12)]; pump+sensor: 30.35% [adjusted-HbA_1c 7.81 (7.77-7.84)]. HbA_1c was lower in all categories of subjects using pump and/or sensor compared to injections-no sensor treatment method (p<0.001, respectively). Proportion of DKA episodes was lower in subjects with pump+sensor [1.98 (1.64-2.48); p<0.001] and pump-no sensor [2.02 (1.64-2.48); p<0.05)] when compared to injections-no sensor [2.91 (2.59-3.31)]. Proportion of SH was lower in pump-no sensor [1.10 (0.85-1.43); p<0.001] but higher in the injections+sensor [4.25 (3.65-4.95); p<0.001] compared to injections-no sensor [2.35 (2.04-2.71)].</p> <p> </p> <p>CONCLUSIONS</p> Lower HbA_1c and fewer DKA episodes were observed in subjects using either a pump, CGM or both. Pump use was associated with lower rate of SH. Across SWEET centers, use of pumps and CGM is increasing. The concomitant use of pump and CGM was found to be associated with an additive benefit.

Glycemic Outcome Associated With Insulin Pump and Glucose Sensor Use in Children and Adolescents With Type 1 Diabetes. Data From the International Pediatric Registry SWEET

OBJECTIVE <p>This study aims to examine insulin delivery methods, glucose monitoring modalities and related outcomes in a large, international, diverse cohort of children and adolescents with type 1 diabetes from the SWEET-Registry</p> <p> </p> <p>RESEARCH DESIGN AND METHODS</p> <p>Participants with type 1 diabetes of <u>></u>1 year of duration, aged ≤18y and documented pump/sensor usage during the period August 2017-July 2019 were stratified into four categories: injections-no sensor (reference); injections+sensor; pump-no sensor; pump+sensor. HbA_1c and proportion of patients with DKA or SH were analyzed; linear and logistic regression models adjusted for demographics, region and gross-domestic-product (GDP)-per capita were applied.</p> <p> </p> <p>RESULTS</p> <p>Data of 25,654 subjects were analyzed. Injections-no sensor: 37.44% [adjusted-HbA_1c 8.72 (95%CI 8.68-8.75)]; injections+sensor: 14.98% [adjusted-HbA_1c 8.30 (8.25-8.35)]; pump-no sensor: 17.22% [adjusted-HbA_1c 8.07 (8.03-8.12)]; pump+sensor: 30.35% [adjusted-HbA_1c 7.81 (7.77-7.84)]. HbA_1c was lower in all categories of subjects using pump and/or sensor compared to injections-no sensor treatment method (p<0.001, respectively). Proportion of DKA episodes was lower in subjects with pump+sensor [1.98 (1.64-2.48); p<0.001] and pump-no sensor [2.02 (1.64-2.48); p<0.05)] when compared to injections-no sensor [2.91 (2.59-3.31)]. Proportion of SH was lower in pump-no sensor [1.10 (0.85-1.43); p<0.001] but higher in the injections+sensor [4.25 (3.65-4.95); p<0.001] compared to injections-no sensor [2.35 (2.04-2.71)].</p> <p> </p> <p>CONCLUSIONS</p> Lower HbA_1c and fewer DKA episodes were observed in subjects using either a pump, CGM or both. Pump use was associated with lower rate of SH. Across SWEET centers, use of pumps and CGM is increasing. The concomitant use of pump and CGM was found to be associated with an additive benefit.

Glycemic Outcome Associated With Insulin Pump and Glucose Sensor Use in Children and Adolescents With Type 1 Diabetes. Data From the International Pediatric Registry SWEET

OBJECTIVE <p>This study aims to examine insulin delivery methods, glucose monitoring modalities and related outcomes in a large, international, diverse cohort of children and adolescents with type 1 diabetes from the SWEET-Registry</p> <p> </p> <p>RESEARCH DESIGN AND METHODS</p> <p>Participants with type 1 diabetes of <u>></u>1 year of duration, aged ≤18y and documented pump/sensor usage during the period August 2017-July 2019 were stratified into four categories: injections-no sensor (reference); injections+sensor; pump-no sensor; pump+sensor. HbA_1c and proportion of patients with DKA or SH were analyzed; linear and logistic regression models adjusted for demographics, region and gross-domestic-product (GDP)-per capita were applied.</p> <p> </p> <p>RESULTS</p> <p>Data of 25,654 subjects were analyzed. Injections-no sensor: 37.44% [adjusted-HbA_1c 8.72 (95%CI 8.68-8.75)]; injections+sensor: 14.98% [adjusted-HbA_1c 8.30 (8.25-8.35)]; pump-no sensor: 17.22% [adjusted-HbA_1c 8.07 (8.03-8.12)]; pump+sensor: 30.35% [adjusted-HbA_1c 7.81 (7.77-7.84)]. HbA_1c was lower in all categories of subjects using pump and/or sensor compared to injections-no sensor treatment method (p<0.001, respectively). Proportion of DKA episodes was lower in subjects with pump+sensor [1.98 (1.64-2.48); p<0.001] and pump-no sensor [2.02 (1.64-2.48); p<0.05)] when compared to injections-no sensor [2.91 (2.59-3.31)]. Proportion of SH was lower in pump-no sensor [1.10 (0.85-1.43); p<0.001] but higher in the injections+sensor [4.25 (3.65-4.95); p<0.001] compared to injections-no sensor [2.35 (2.04-2.71)].</p> <p> </p> <p>CONCLUSIONS</p> Lower HbA_1c and fewer DKA episodes were observed in subjects using either a pump, CGM or both. Pump use was associated with lower rate of SH. Across SWEET centers, use of pumps and CGM is increasing. The concomitant use of pump and CGM was found to be associated with an additive benefit.

Fusão Hierárquica de Dados para Sistemas de Computação em Névoa

O paradigma da computação em névoa possibilita que os recursos computacionais sejam levados para a borda da rede, de forma que a latência e a largura de banda resultantes da computação em nuvem possam ser reduzidas. A combinação desse paradigma com técnicas de fusão de dados e processamento de eventos, a partir da aquisição de dados brutos, tem grande potencial de uso para gerar conhecimento de valor e ajudar a tomada de decisão em sistemas de IoT. Nesse contexto, foi proposta uma arquitetura de fusão de dados em três níveis (nó sensor, névoa e nuvem) que, aliada ao uso de técnicas de processamento de eventos complexos, promove a tomada de decisões com rapidez, enquanto reduz o custo de transmissão de dados na rede. Os experimentos mostram uma redução de 77% no tempo médio de envio de mensagens na rede e 82% de melhoria na vazão média com a utilização da arquitetura proposta.