From Science direct: One of the nanowires was covered with a 2-Hydroxyethyl methacrylate based compound to prevent hydrogen from reaching the wire. The compound was dried by a UV source and tested in chamber for comparison with previous measurements. The results shows that temperature effects can be reduced by a digital signal processing algorithm without measuring temperature near or at the substrate. With this method no additional temperature probes are necessary making this solution a candidate for ultra low power wireless applications.
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from the article: The demand for a wireless CO2 solution is ever increasing. One of the biggest problems with the majority of commercial available CO2 sensors is the high energy consumption which makes them unsuitable for battery operation. Possible candidates for CO2 sensing in a low power wireless application are very limited and show a problematic calibration process. This study focuses on one of those EMF candidates, which is a Ag4RbI5 based sensor. This EMF sensor is based on the potentiometric principle and consumes no energy. The EMF cell was studied in a chamber where humidity, temperature and CO2 level could be controlled. This study gives an detailed insight in the different drift properties of the potentiometric CO2 sensor and a method to amplify the sensors signal. Furthermore, a method to minimize the several types of drift is given. With this method the temperature drift can be decreased by a factor 10, making the sensor a possible candidate for a wireless CO2 sensor network.
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From Springer description: "We present the design considerations of an autonomous wireless sensor and discuss the fabrication and testing of the various components including the energy harvester, the active sensing devices and the power management and sensor interface circuits. A common materials platform, namely, nanowires, enables us to fabricate state-of-the-art components at reduced volume and show chemical sensing within the available energy budget. We demonstrate a photovoltaic mini-module made of silicon nanowire solar cells, each of 0.5 mm2 area, which delivers a power of 260 μW and an open circuit voltage of 2 V at one sun illumination. Using nanowire platforms two sensing applications are presented. Combining functionalised suspended Si nanowires with a novel microfluidic fluid delivery system, fully integrated microfluidic–sensor devices are examined as sensors for streptavidin and pH, whereas, using a microchip modified with Pd nanowires provides a power efficient and fast early hydrogen gas detection method. Finally, an ultra-low power, efficient solar energy harvesting and sensing microsystem augmented with a 6 mAh rechargeable battery allows for less than 20 μW power consumption and 425 h sensor operation even without energy harvesting."
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Author supplied: Abstract—The growing importance and impact of new technologies are changing many industries. This effect is especially noticeable in the manufacturing industry. This paper explores a practical implementation of a hybrid architecture for the newest generation of manufacturing systems. The papers starts with a proposition that envisions reconfigurable systems that work together autonomously to create Manufacturing as a Service (MaaS). It introduces a number of problems in this area and shows the requirements for an architecture that can be the main research platform to solve a number of these problems, including the need for safe and flexible system behaviour and the ability to reconfigure with limited interference to other systems within the manufacturing environment. The paper highlights the infrastructure and architecture itself that can support the requirements to solve the mentioned problems in the future. A concept system named Grid Manufacturing is then introduced that shows both the hardware and software systems to handle the challenges. The paper then moves towards the design of the architecture and introduces all systems involved, including the specific hardware platforms that will be controlled by the software platform called REXOS (Reconfigurable EQuipletS Operating System). The design choices are provided that show why it has become a hybrid platform that uses Java Agent Development Framework (JADE) and Robot Operating System (ROS). Finally, to validate REXOS, the performance is measured and discussed, which shows that REXOS can be used as a practical basis for more specific research for robust autonomous reconfigurable systems and application in industry 4.0. This paper shows practical examples of how to successfully combine several technologies that are meant to lead to a faster adoption and a better business case for autonomous and reconfigurable systems in industry.
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Several studies have suggested that precision livestock farming (PLF) is a useful tool foranimal welfare management and assessment. Location, posture and movement of an individual are key elements in identifying the animal and recording its behaviour. Currently, multiple technologies are available for automated monitoring of the location of individual animals, ranging from Global Navigation Satellite Systems (GNSS) to ultra-wideband (UWB), RFID, wireless sensor networks (WSN) and even computer vision. These techniques and developments all yield potential to manage and assess animal welfare, but also have their constraints, such as range and accuracy. Combining sensors such as accelerometers with any location determining technique into a sensor fusion systemcan give more detailed information on the individual cow, achieving an even more reliable and accurate indication of animal welfare. We conclude that location systems are a promising approach to determining animal welfare, especially when applied in conjunction with additional sensors, but additional research focused on the use of technology in animal welfare monitoring is needed.
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The COVID-19 pandemic has forced higher education (HE) to shift to emergency remote teaching (ERT), subsequently influencing academic belonging and social integration, as well as challenging students' engagement with their studies. This study investigated influences on student engagement during ERT, based on student resilience. Serial mediation analyses were used to test the predictive effects between resilience, academic belonging, social integration, and engagement.
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Twirre is a new architecture for mini-UAV platforms designed for autonomous flight in both GPS-enabled and GPS-deprived applications. The architecture consists of low-cost hardware and software components. High-level control software enables autonomous operation. Exchanging or upgrading hardware components is straightforward and the architecture is an excellent starting point for building low-cost autonomous mini-UAVs for a variety of applications. Experiments with an implementation of the architecture are in development, and preliminary results demonstrate accurate indoor navigation
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In this work, in situ measurements of the radio frequency electromagnetic field exposure have been conducted for an indoor massive MIMO 5G base station operating at 26–28 GHz. Measurements were performed at six different positions (at distances between 9.94 and 14.32 m from the base station), of which four were in line-of-sight and two were in non-line-of-sight. A comparison was performed between the measurements conducted with an omnidirectional probe and with a horn antenna, for scenarios with and without a user equipment used to actively create an antenna traffic beam from the base station towards the measurement location. A maximum exposure of 171.9 mW/m2 was measured at a distance of 9.94 m from the base station. This is below 2% of the ICNIRP reference level. Moreover, the feasibility to measure the power per resource element of the Synchronization Signal Block - which can be used to extrapolate the maximum exposure level - with a conventional spectrum analyzer was shown by comparison with a network decoder.
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Elke periode kent zijn eigen revolutie en elke revolutie brengt zijn eigen organisatorische model met zich mee. We bevinden ons nu in de 4e industri¨ele revolutie, waar het internet van dingen ons verbindt met autonome embedded systemen. Deze systemen zijn actief in de virtuele ’cyber’ wereld, alsook in de echte ’fysieke’ wereld om ons heen. Deze zogenoemde ’Cyber-Fysieke’ Systemen volgen daarmee een modern organisatorisch model, namelijk zelfmanagement, en zijn dan ook in staat zelf proactieve acties te ondernemen. Dit proefschrift belicht productiesystemen vanuit het Cyber-Fysieke perspectief. De productiesystemen zijn hier herconfigureerbaar, autonoom en zeer flexibel. Dit kan enkel worden bereikt door het ontwikkelen van nieuwe methodes en het toepassen van nieuwe technologie¨en die flexibiliteit verder bevorderen. Echter, effici¨entie is ook van belang, bijvoorbeeld door productassemblage zo flexibel te maken dat het daardoor kosteneffici¨ent is om de productie van diverse producten met een lage oplage, zogenaamde high-mix, low volume producten, te automatiseren. De mogelijkheid om zo flexibel te kunnen produceren moet bereikt worden door de creatie van nieuwe methoden en middelen, waarbij nieuwe technologie¨en worden gecombineerd; een belangrijk aspect hierbij is dat dit toepasbaar getest moet worden door gebruik van simulatoren en speciaal hiervoor ontwikkelde productiesystemen. Dit onderzoek zal beginnen met het introduceren van het concept achter de bijbehorende productiemethodologie, welke Grid Manufacturing is genoemd. Grid Manufacturing wordt uitgevoerd door autonome entiteiten (agenten) die zowel de productiesystemen zelf, als de producten representeren. Producten leven dan al in de virtuele cyber wereld voordat zij daadwerkelijk zijn gebouwd, en zijn zich bewust uit welke onderdelen zij gemaakt moeten worden. De producten communiceren en overleggen met de autonome herconfigureerbare productiesystemen, de zogenaamde equiplets. Deze equiplets leveren generieke diensten aan een grote diversiteit aan producten, die hierdoor op elk moment geproduceerd kunnen worden. Het onderzoek focust hierbij specifiek op de equiplets en de technische uitdagingen om dynamisch geautomatiseerde productie mogelijk te maken. Om Grid Manufacturing mogelijk te maken is er een set van technologische uitdagingen onderzocht. De achtergrond, onderzoeksaanpak en concepten zijn dan ook de eerste drie inleidende hoofdstukken. Daarna begint het onderzoek met Hoofdstuk 4 Object Awareness. Dit hoofdstuk beschrijft een dynamische manier waarop informatie uit verschillende autonome systemen gecombineerd wordt om objecten te herkennen, lokaliseren en daarmee te kunnen manipuleren. Hoofdstuk 5 Herconfiguratie beschrijft hoe producten communiceren met de equiplets en welke achterliggende systemen ervoor zorgen dat, ondanks | Dutch Summary 232 dat het product niet bekend is met de hardware van de equiplet, deze toch in staat is acties uit te voeren. Tevens beschrijft het hoofdstuk hoe de equiplets omgaan met verschillende hardwareconfiguraties en ondanks de aanpassingen zichzelf toch kunnen besturen. De equiplet kan dan ook aangepast worden zonder dat deze opnieuw geprogrammeerd hoeft te worden. In Hoofdstuk 6 Architectuur wordt vervolgens dieper ingegaan op de bovenliggende architectuur van de equiplets. Hier worden prestaties gecombineerd met flexibiliteit, waarvoor een hybride architectuur is ontwikkeld die het grid van equiplets controleert door het gebruik van twee platformen: Multi-Agent System (MAS) en Robot Operating System (ROS). Nadat de architectuur is vastgesteld, wordt er in Hoofdstuk 7 onderzocht hoe deze veilig ingezet kan worden. Hierbij wordt een controlesysteem ingevoerd dat het systeemgedrag bepaalt, waarmee het gedrag van de equiplets transparant wordt gemaakt. Tevens zal een simulatie met input van de sensoren uit de fysieke wereld ’live’ controleren of alle bewegingen veilig uitgevoerd kunnen worden. Nadat de basisfunctionaliteit van het Grid nu compleet is, wordt in Hoofdstuk 8 Validatie en Utilisatie gekeken naar hoe Grid Manufacturing gebruikt kan worden en welke nieuwe mogelijkheden deze kan opleveren. Zo wordt er besproken hoe zowel een hi¨erarchische als een heterarchische aanpak, waar alle systemen gelijk zijn, gebruikt kan worden. Daarnaast laat het hoofdstuk o.a. aan de hand van enkele voorbeelden en simulaties zien welke effecten herconfiguratie kan hebben, en welke voordelen deze aanpak zoal kan bieden.. Het proefschrift laat zien hoe met technische middelen geautomatiseerde flexibiliteit mogelijk wordt gemaakt. Hoewel het gehele concept nog volwassen zal moeten worden, worden er enkele aspecten getoond die op de korte termijn toepasbaar zijn in de industrie. Enkele voorbeelden hiervan zijn: (1) het combineren van gegevens uit diverse (autonome) bronnen voor 6D-lokalisatie; (2) een data-gedreven systeem, de zogeheten hardware-abstractielaag, die herconfigureerbare systemen controleert en de mogelijkheid biedt om deze productiesystemen aan te passen zonder deze te hoeven herprogrammeren; en (3) het gebruik van Cyber-Fysieke systemen om de veiligheid te verhogen.
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Quantifying measures of physical loading has been an essential part of performance monitoring within elite able-bodied sport, facilitated through advancing innovative technology. In wheelchair court sports (WCS) the inter-individual variability of physical impairments in the athletes increases the necessity for accurate load and performance measurements, while at the same time standard load monitoring methods (e.g. heart-rate) often fail in this group and dedicated WCS performance measurement methods are scarce. The objective of this review was to provide practitioners and researchers with an overview and recommendations to underpin the selection of suitable technologies for a variety of load and performance monitoring purposes specific to WCS. This review explored the different technologies that have been used for load and performance monitoring in WCS. During structured field testing, magnetic switch based devices, optical encoders and laser systems have all been used to monitor linear aspects of performance. However, movement in WCS is multidirectional, hence accelerations, decelerations and rotational performance and their impact on physiological responses and determination of skill level, is also of interest. Subsequently both for structured field testing as well as match-play and training, inertial measurement units mounted on wheels and frame have emerged as an accurate and practical option for quantifying linear and non-linear movements. In conclusion, each method has its place in load and performance measurement, yet inertial sensors seem most versatile and accurate. However, to add context to load and performance metrics, position-based acquisition devices such as automated image-based processing or local positioning systems are required.
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