Improving the communication reliability of body sensor networks based on the IEEE 802.15.4 protocol

Body sensor networks (BSNs) enable continuous monitoring of patients anywhere, with minimum constraints to daily life activities. Although the IEEE 802.15.4 and ZigBee® (ZigBee Alliance, San Ramon, CA) standards were mainly developed for use in wireless sensors network (WSN) applications, they are also widely used in BSN applications because of device characteristics such as low power, low cost, and small form factor. However, compared with WSNs, BSNs present some very distinctive characteristics in terms of traffic and mobility patterns, heterogeneity of the nodes, and quality of service requirements. This article evaluates the suitability of the carrier sense multiple access–collision avoidance protocol, used by the IEEE 802.15.4 and ZigBee standards, for data-intensive BSN applications, through the execution of experimental tests in different evaluation scenarios, in order to take into account the effects of contention, clock drift, and hidden nodes on the communication reliability. Results show that the delivery ratio may decrease substantially during transitory periods, which can last for several minutes, to a minimum of 90% with retransmissions and 13% without retransmissions. This article also proposes and evaluates the performance of the BSN contention avoidance mechanism, which was designed to solve the identified reliability problems. This mechanism was able to restore the delivery ratio to 100% even in the scenario without retransmissions.Fundação para a Ciência e a Tecnologia (FCT

A smartphone-based multi-sensor wireless platform for cycling performance monitoring

In recent years there has been a significant evolution regarding applications for mobile devices that provide location-based services. The mobile devices available on the market already provide a set of integrated sensors and it is also possible to acquire data from external sensors. This chapter presents the development and results concerning a mobile sensing platform applied to cycling which performs data collection using both sensors integrated in the smartphone and multiple wireless sensor nodes, which are used to acquire relevant performance parameters. The data collected by the developed mobile app is stored in a local database and also uploaded to a remote database, where it can be accessed later using the mobile app or a web browser. This mobile app allows users to share data with friends, join or create events, locate friends, consult graphs and access past routes in a map. Based on these functionalities, this system aims to provide detailed feedback regarding the user performance and enhance the enjoyment of the cyclists.This work has been supported by FCT (Fundação para a Ciência e Tecnologia) in the scope of the project: UID/EEA/04436/2013.info:eu-repo/semantics/publishedVersio

Experimental evaluation of ZigBee and IEEE 802.15.4 for data-intensive body sensor networks

This paper presents results concerning an experimental performance evaluation of ZigBee and IEEE 802.15.4 networks applied to the transport of data-intensive traffic generated by body sensor network applications. The experimental platform is based on the Z-Stack and TIMAC software stacks and the CC2530 device, from Texas Instruments. Three quality of service metrics are evaluated: goodput, delivery ratio and delay. Results are provided for both star and tree topologies. It was observed that the overhead introduced by the stack implementation has a significant impact on the performance results. Overall, the performance of the ZigBee star topology was very good, even in the worst conditions, provided the acknowledgement mechanism was enabled. A router deadlock problem detected in other ZigBee implementations was not observed with the Z-Stack. However, we identified two different situations, triggered by periods of high traffic load, on which the ZigBee router stops relaying packets, causing a significant degradation on the network performance.Fundação para a Ciência e a Tecnologia (FCT

Detection of azo dyes using carbon dots from olive mill wastes

Azo dyes are widely spread in our day life, being heavily used in cosmetics, healthcare products, textile industries, and as artificial food colorants. This intense industrial activity, which inherently includes their own production, inexorably leads to uncontrolled release of dyes into the environment. As emerging pollutants, their detection, particularly in water systems, is a priority. Herein, a fluorescence-based method was employed for the sensitive and selective detection of anionic and neutral azo dyes. Carbon dots (CDs) synthesized from wet pomace (WP), an abundant semi-solid waste of olive mills, were used as probes. An outstanding capability for detection of azo dyes methyl orange (MO) and methyl red (MR) in aqueous solutions was disclosed, which reached a limit of detection (LOD) of 151 ppb for MO. The selectivity of WP-CDs for the anionic azo dye (MO) was established through competitive experiments with other dyes, either anionic (indigo carmine) or cationic (fuchsin, methylene blue, and rhodamine 6G); perchlorate salts of transition metal cations (Cu(II), Co(II), Fe(II), Fe(III), Hg(II), and Pb(II)); and sodium salts of common anions (NO3-, CO32-, Cl-, and SO42-). Evidence has been collected that supports static quenching as the main transduction event underlying the observed quenching of the probe's fluorescence, combined with a dynamic resonance energy transfer (RET) mechanism at high MO concentrations.info:eu-repo/semantics/publishedVersio

A Theoretical Contribution To Improve The Formation In The Historical Lisbon School Of Architecture - The Forgotten Dimension of the Technological Perspective

This article approaches the problem of the absence of the technology in the didactics of the Architecture´s Design, in the course of School of Architecture of Lisbon, as the subtitle of the article suggests - the forgotten dimension of the technological perspective.Despite of the course contemplates a relevant technological component, however, does not reflect, much less exponent the creative act of the Project. This is first of all a result of the organization, didactics and contents of the Project classes, and not so much, a lack of knowledge provided to the student in the technological disciplines, which are present in quantity in the curricular structure. The situation, analyzed in this article, is a consequence of a blocking of the Project classes to the technology ones, which do not promote, nor allow, the necessary transdisciplinary articulation and integration between the act of designing and the application of technological knowledge, which is fundamental and intrinsic to the act of thinking and conceiving Architecture.The CAD / CAE / CAM digital tools have not only highlighted the fragility of this didactic process in the didactic context of the current teaching, but, in view of the potential of its operative process, impose the future reformulation of the Project's cognitive practice, integrating the component technology in the Design Methodology of the architect's teaching and praxisN/

Sistemas complexos, modelação e geossimulação da evolução do espaço urbano

A utilização da computação na manipulação de modelos, i.e. geosimulação tornou possível o processamento paralelo de inúmeras variáveis e também aplicar regras de crescimento na forma de algoritmos que permitem acrescentar, entre outros factores, elementos aleatórios ao modelo. O trabalho aqui apresentado é um exemplo prático da utilização da modelação aliada a conceitos como a complexidade e a emergência na procura de representações dinâmicas do crescimento urbano. O submodelo preditivo é uma das características principais deste(s) modelo(s), pelo se testaram várias abordagens possíveis para a sua realização, apresentando-se os resultados e as especificidades de cada uma delas.info:eu-repo/semantics/publishedVersio

Data fusion approach for eucalyptus trees identification

UIDB/00066/2020 DSAIPA/AI/0100/2018Remote sensing is based on the extraction of data, acquired by satellites or aircrafts, through multispectral images, that allow their remote analysis and classification. Analysing those images with data fusion techniques is a promising approach for identification and classification of forest types. Fusion techniques can aggregate various sources of heterogeneous information to generate value-added maps, facilitating forest-type classification. This work applies a data fusion algorithm, denoted FIF (Fuzzy Information Fusion), which combines computational intelligence techniques with multicriteria concepts and techniques, to automatically distinguish Eucalyptus trees from satellite images. The algorithm customization was performed with a Portuguese area planted with Eucalyptus. After customizing and validating the approach with several representative scenarios to assess its suitability for automatic classification of Eucalyptus, we tested on a large tile obtaining a sensitivity of 69.61%, with a specificity of 99.43%, and an overall accuracy of 98.19%. This work demonstrates the potential of our approach to automatically classify specific forest types from satellite images, since this is a novel approach dedicated to the identification of eucalyptus trees.publishersversionpublishe

Effect of Dietary Laminaria digitata with Carbohydrases on Broiler Production Performance and Meat Quality, Lipid Profile, and Mineral Composition

This article belongs to the Section Animal Nutrition.Simple Summary: Seaweeds represent promising alternatives to unsustainable conventional feed sources, such as cereals, incorporated in poultry diets. Brown macroalgae (e.g., Laminaria digitata) correspond to the largest cultured algal biomass worldwide and are rich in bioactive polysaccharides, minerals, and antioxidant pigments. However, their utilization as feed ingredients is limited due to the presence of an intricate gel-forming cell wall composed of indigestible carbohydrates, mainly alginate and fucose-containing sulfated polysaccharides. Therefore, supplementation with carbohydrate-active enzymes is required to disrupt the cell wall and allow seaweed nutrients to be digested and absorbed in poultry gut. The present study aimed to evaluate if the dietary inclusion of 15% L. digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing growth performance of broiler chickens. The results show that L. digitata increases antioxidant pigments and n-3 long-chain polyunsaturated fatty acids in meat, thus improving meat nutritional and health values. On the other hand, feeding algae at a high incorporation level impaired growth performance. Feed enzymatic supplementation had only residual effects, although alginate lyase decreased intestinal viscosity caused by dietary L. digitata with potential benefits for broiler digestibility.Abstract: We hypothesized that dietary inclusion of 15% Laminaria digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing animal growth performance. A total of 120 22-day old broilers were fed the following dietary treatments (n = 10) for 14 days: cereal-based diet (control); control diet with 15% L. digitata (LA); LA diet with 0.005% Rovabio® Excel AP (LAR); LA diet with 0.01% alginate lyase (LAE). Final body weight was lower and feed conversion ratio higher with LA diet than with the control. The ileal viscosity increased with LA and LAR diets relative to control but without differences between LAE and control. The pH of thigh meat was higher, and the redness value of breast was lower with LA diet than with control. Meat overall acceptability was positively scored for all treatments. The γ-tocopherol decreased, whereas total chlorophylls and carotenoids increased in meat with alga diets relative to control. The percentage of n-3 polyunsaturated fatty acids (PUFA) and accumulation of bromine and iodine in meat increased with alga diets compared with control. Feeding 15% of L. digitata to broilers impaired growth performance but enhanced meat quality by increasing antioxidant pigments, with beneficial effects on n-3 PUFA and iodine.The study was funded by the Fundação para a Ciência e a Tecnologia, Portugal, through the PTDC/CAL-ZOO/30238/2017 grant, associated with a postdoctoral contract to M.M.C. and a PhD fellowship to D.C. (SFRH/BD/126198/2016), as well as CIISA (UIDB/00276/2020), AL4AnimalS (LA/P/0059/2020), and LEAF (UIDB/04129/2020) grants.info:eu-repo/semantics/publishedVersio

Let's End HepC: modelling public health epidemiological policies applied to Hepatitis C in Spain

Background: The WHO has defined international targets toward the elimination of hepatitis C by 2030. Most countries cannot be on track to achieve this goal unless many challenges are surpassed. The Let's End HepC (LEHC) tool aims to contribute to the control of hepatitis C. The innovation of this tool combines the modelling of public health policies (PHP) focused on hepatitis C with epidemiological modelling of the disease, obtaining a unique result that allows to forecast the impact of policy outcomes. The model was applied to several countries, including Spain. Methods: To address the stated objective, we applied the “Adaptive Conjoint Analysis” for PHP decision-making and Markov Chains in the LEHC modelling tool. The tool also aims to be used as an element of health literacy for patient advocacy through gamification mechanisms and country comparability. The LEHC project has been conducted in several countries, including Spain. The population segments comprised in the project are: People Who Inject Drugs (PWID), prisoners, blood products, remnant population. Results: A total of 24 PHP related to hepatitis C were included in the LEHC project. It was identified that Spain had fully implemented 14 of those policies to control hepatitis C. According to LEHC's model forecast, the WHO's Hepatitis C elimination goal on reducing the number of patients living with Hepatitis C to 10% can be achieved in Spain by 2026 if current policies are maintained. The model estimates that the total population in Spain, by 2026, is expected to comprise 26,367 individuals living with hepatitis C. Moreover, if the 24 PHP considered for this study are fully implemented in Spain, the elimination goal may be achieved in 2024, with 29,615 individuals living with hepatitis C by that year. Conclusion: The findings corroborate the view that Spain has set great efforts in directing PHP toward Hepatitis C Virus (HCV) elimination by 2030. However, there is still room for improvement, namely in further implementing 10 of the 24 PHP considered for the LEHC project. By maintaining the 14 PHP in force, the LEHC model estimates the HCV elimination in the country by 2026, and by 2024 if further measures are employed to control the disease.info:eu-repo/semantics/publishedVersio

A systematic analysis of printed circuit boards bending during in-circuit tests

When performing In-Circuit Tests (ICTs) of Printed Circuit Boards (PCBs), there are certain phenomena related with strain analysis that must be known in order to obtain stronger and more accurate testing results. During testing, PCBs are often subjected to mechanical bending efforts that induce excessive strain. This study focuses on the building of a Finite Elements Analysis (FEA) methodology that prevents excessive bending strain in critical points of a PCB during an ICT. To validate this methodology, a set of experimental tests, matched with a set of FEA, were carried out. Thus, companies, before the development of an ICT machine (fixture), will be able to use this FEA methodology to predict whether the maximum strain of a PCB under study, when subjected to its ICT, will damage it, thus reducing unnecessary production costs. A guideline was thus designed to enable the creation of the most representative Finite Elements Model (FEM) for any PCB, based on its amount and direction of copper traces.This work is co-funded by the European Regional Development Fund (ERDF) through the North Regional Operational Program (NORTE 2020) of the Portugal 2020 Program (Project No. 43922, with acronym “iFixturing”; Funding Reference NORTE-01-0247-FEDER-043922)