Search results for " sensor"
showing 10 items of 1714 documents
An Intra-Subject Approach Based on the Application of HMM to Predict Concentration in Educational Contexts from Nonintrusive Physiological Signals in…
2021
Previous research has proven the strong influence of emotions on student engagement and motivation. Therefore, emotion recognition is becoming very relevant in educational scenarios, but there is no standard method for predicting students’ affects. However, physiological signals have been widely used in educational contexts. Some physiological signals have shown a high accuracy in detecting emotions because they reflect spontaneous affect-related information, which is fresh and does not require additional control or interpretation. Most proposed works use measuring equipment for which applicability in real-world scenarios is limited because of its high cost and intrusiveness. To tackle this…
Characterization of impervious layers using scale models and an inverse method
2009
We describe a novel procedure that uses an inverse method to determine unknown parameters for impervious layers used in multilayer structures. The proposed model of the multilayer structure is limited to an ideal double plate separated by an unbonded, fibrous, sound-absorbing material. Experimental data were obtained by nearfield acoustic holography for the calculation of the transmission loss of various multilayer structures mounted in a window in a wooden box designed specifically for this purpose. We used the Trochidis and Kalaroutis forecast model of acoustic insulation for multilayer structures, which is based on a spatial Fourier transform. The experimental pressure and velocity data …
Optical Plasmonic Nanoantenna-MWCNT diode Energy Harvester for Solar Powered Wireless Sensors
2021
This paper presents the design of an optical energy-harvester (EH) to power wireless IoT sensors. For the first time, the simulation results of the complete nanorectenna-electronic system are reported, consisting of an N*M Ag-Ti arrow bowtie nanoantenna - MWCNT-I-M diode array, a low-pass filter, and a DC-DC converter. An output voltage value of 3.3 V and an output current of 10 mA were obtained with a 49498*14286 optical array with an area of about 63, 64 mm2. The proposed optical EH paves the way for the replacement of batteries with solar energy, overcoming the limit of photovoltaic applications in wireless IoT sensors.
Development of a Low-Cost IoT System for Lightning Strike Detection and Location
2019
Lightning and thunder are some of the most violent natural phenomena. They generate a great deal of expenditure and economic loss, especially when they strike in cities. The identification of the concrete geographic area where they strike is of critical importance for emergency services in order to enhance their effectiveness by doing an intensive coverage of the affected area. To achieve this purpose at the city scale, this paper proposes the design, prototype, and validation of a distributed network of Internet of Things (IoT) devices. The IoT devices are empowered with lightning detection capabilities and are synchronized with the other devices in the sensor network. All of them cooperat…
A data aggregation strategy based on wavelet for the internet of things
2017
The advent of emerging information and communication technologies, such as RFID, small size sensors and sensor networks, has made accessible a huge amount of information that requires sophisticated and efficient search algorithms to support queries on that data. In this paper we focus on the problem of aggregating data collected from these devices to efficiently support queries, inferences or statistics on them. In general, data aggregation techniques are necessary to efficiently collect information in a compact and cost-effective way. Some current solutions try to meet the above criteria, by exploiting different data aggregation techniques, for instance BitVector or Q_Digest. In this manus…
Classification of Actual Sensor Network Deployments in Research Studies from 2013 to 2017
2020
Technologies, such as Wireless Sensor Networks (WSN) and Internet of Things (IoT), have captured the imagination of researchers, businesses, and general public, due to breakthroughs in embedded system development, sensing technologies, and ubiquitous connectivity in recent years. That resulted in the emergence of an enormous, difficult-to-navigate body of work related to WSN and IoT. In an ongoing research effort to highlight trends and developments in these technologies and to see whether they are actually deployed rather than subjects of theoretical research with presumed potential use cases, we gathered and codified a dataset of scientific publications from a five-year period from 2013 t…
Structure Monitoring with BIM and IoT: The Case Study of a Bridge Beam Model
2022
The diffusion of Building Information Modelling (BIM) as a reference methodology, applied to the world of construction, leads to important changes in the design and the management of big constructions and infrastructures. However, although the BIM approach is necessary for managing the entire life cycle of a construction, today, this methodology is still rarely adopted beyond the design phase. This represents a major flaw because the management of every phase of the life cycle of buildings needs accurate preliminary planning. Certainly, one of the most complex and important phases of the life cycle of a construction is the monitoring phase, which represents a fundamental aspect for the main…
Demo abstract: Cross-technology TDMA synchronization using energy pattern beacons
2017
When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and require technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, an architecture that allows cross-technology medium access by means of a Time Division Multiple Access (TDMA) scheme was devised. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon is trans…
Desarrollo y análisis de sensores inalámbricos y sistemas asociados de IoT
2023
En los últimos años, la tecnología del Internet de las cosas (IoT) se ha vuelto cada vez más importante. Al ofrecer un medio para conectar dispositivos y establecer conexiones en tiempo real, el IoT ha facilitado el monitoreo y la gestión de entidades tangibles, como electrodomésticos, vehículos y edificios. Típicamente, un sistema IoT incorpora numerosos dispositivos que se comunican entre sí a través de gateways y servidores en la nube que alojan aplicaciones web y móviles. Los usuarios finales pueden interactuar sin problemas con sus dispositivos IoT, lo que les otorga una mayor accesibilidad y conveniencia. Dado su capacidad para proporcionar control y automatización en tiempo real, el …
LoRaWAN datu pārraides tīkla veiktspējas novērtējums Rīgas pilsētā un tās apkaimē
2018
Zemas enerģijas patēriņa, plaša pārklājuma datu pārraides tehnoloģijas (LPWAN) pēdējo gadu laikā arvien vairāk tiek izmantotas dažādu tautsaimniecības problēmu risināšanai. Paralēli noris aktīvi šo tehnoloģiju pētījumi un attīstība, kā arī meklēti praktiski tehnoloģiju pielietojumi lietu interneta (Internet of Things jeb IoT) vidē. Darba mērķis ir izpētīt zemas enerģijas patēriņa, liela pārklājuma bezvadu datu pārraides tehnoloģijas un to realizāciju ar LoRaWAN tehnoloģijas palīdzību. Papildu teorētiskajiem pētījumiem, darba mērķis ir praktiski pārbaudīt, vai LoRaWAN datu pārraides pārklājums atbilst dokumentācijā aprakstītajam, ka pilsētā tas var sasniegt līdz pat 8 km distanci. Darba prak…