Search results for " sensor"
showing 10 items of 1714 documents
Evolution of otosclerosis to cochlear implantation.
2011
Abstract Introduction Otosclerosis is an osteodystrophy of the labyrinthine capsule producing conductive hearing loss. If the process invades the cochlea, a sensorineural hearing loss usually takes place. The cochlear implant is a good alternative in these patients. Objective To ascertain the behaviour of cochlear implantation (CI) in otosclerosis. Material and methods We reviewed a database of 250 patients who underwent CI, performing a retrospective study of 13 patients with clinical, audiological and/or imaging findings of bilateral otosclerosis. The 26 ears were studied as to their natural history, previous surgeries, evolution to profound hearing loss, computed tomography (CT) images, …
Improving Children's Coordinative Skills and Executive Functions
2016
Recent studies have focused on the positive influence of regular physical activity on executive functioning in children. Coordinative skills (agility) and executive functions (updating, attention, inhibition and planning processes) were investigated in children before and after 6 months of a Football Exercise Program compared to a control group of sedentary peers. The participants were 44 children aged 8.8 years: Group 1 comprised 24 children in a football (i.e., soccer) exercise program and Group 2 comprised 20 sedentary children. At pre-test and post-test, coordinative skills and executive functions were measured. After the Football Exercise Program, there were significant differences be…
Numerical study for a new methodology of flaws detection in train axles
2013
Train loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20 years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coup…
Closing the sensing-reasoning-actuating loop in resource-constrained WSANs through distributed symbolic processing
2015
Many issues in creating complex applications for pervasive environments are primarily due to the effort required to integrate perception, reasoning and actuating tasks in an efficient and homogeneous way, especially when the underlying infrastructure consists of wirelessly networked embedded devices. To mitigate the complexity of the actual implementation, satisfactory programming paradigms supporting the integration and coordination among heterogeneous devices are required. In this paper we show how a distributed symbolic processing approach that is particularly suited for resource constrained devices, such as the nodes of a Wireless Sensor and Actuator Network (WSAN), may be apt to the pu…
JIFAM Special Issue on Experiential Marketing: Perspectives from the International Agro-food Sector
2022
Globalization in the food sector has increased over the past few decades, resulting in consumers finding little differentiation between food products, and consumers who are less loyal to the brand. To help overcome this problem, food companies are trying to shift the consumer’s attention from the product itself toward other elements, such as the experience they have with the brand/product and the emotions that derive from it, through Experiential Marketing. The rise of Experiential Marketing has led to businesses advertising and selling their offerings based on experiences rather than just the characteristics and quality of the product, meaning consumers are increasingly motivated by emotio…
Energy Harvesting Powered Packet Transmissions in Duty-Cycled WSNs: A DTMC Analysis
2017
Energy harvesting (EH) promises an extended lifetime for wireless sensor networks (WSNs), supplying sensor nodes with accumulated energy from natural sources. Different from battery powered sensors, nodes in EH-enabled WSNs are equipped with an energy harvesting accessory in order to extract energy from surrounding sources. Based upon the harvested energy, sensor nodes perform data exchange activities. In this paper, we develop two discrete time Markov chain (DTMC) models to analyze the performance of packet transmissions in such a WSN while employing a generic synchronous medium access control (MAC) protocol. Using the proposed DTMC models, we investigate the effect of EH over a specific s…
Collision Avoidance in Wake-Up Radio Enabled WSNs: Protocol and Performance Evaluation
2018
In wake-up radio (WuR) enabled wireless sensor networks (WSNs), the envisaged application scenarios are primarily targeted at low traffic load conditions. When applying WuR to medium or heavy traffic load scenarios, however, collisions among wake-up calls (WuCs) may happen, resulting in a lower packet delivery ratio (PDR). In this paper, we propose a media access control protocol for WuR- enabled WSN that is capable of avoiding WuC collisions by activating a contention-based collision avoidance mechanism for WuC transmissions. The performance of the proposed protocol is evaluated by a Markov chain based mathematical model and is compared with a WuR protocol that performs only clear channel as…
Event-Triggered Sleeping for Synchronous DC MAC IN WSNs: Mechanism and DTMC Modeling
2016
Overhearing and idle listening are two primary sources for unnecessary energy consumption in wireless sensor networks. Although introducing duty cycling in medium access control (MAC) reduces idle listening, it cannot avoid overhearing in a network with multiple contending nodes. In this paper, we propose an event-triggered sleeping (ETS) mechanism for synchronous duty-cycled (DC) MAC protocols in order to avoid overhearing when a node is not active. This ETS mechanism applies to any synchronous DC MAC protocols and makes them more energy efficient. Furthermore, we develop a two dimensional discrete time Markov chain model to evaluate the performance of the proposed ETS mechanism by integra…
Energy Efficient Consecutive Packet Transmissions in Receiver-Initiated Wake-Up Radio Enabled WSNs
2018
In wake-up radio (WuR)-enabled wireless sensor networks, data communication among nodes is triggered in an on-demand manner, by either a sender or a receiver. For receiver-initiated WuR (RI-WuR), a receiving node wakes up sending nodes through a wake-up call. Correspondingly sending nodes transmit packets in a traditional way by competing with one another multiple times in a single operational cycle. In this paper, we propose a receiver-initiated consecutive packet transmission WuR (RI-CPT-WuR) medium access control (MAC) protocol, which eliminates multiple competitions to achieve higher energy efficiency. Furthermore, we develop two associated discrete time Markov chains (DTMCs) for evalua…
Bezvadu sensoru tīkla maršrutēšanas protokola izstrāde
2022
Maģistra darba “Bezvadu sensoru tīkla maršrutēšanas protokola izstrāde” mērķis ir izpētīt citu autoru sniegumu maršrutēšanas protokolu modeļu izstrādē, aplūkot maršrutēšanas protokolus, kuri izmanto paredzēšanu, modeļus, kā arī aplūkot bezvadu sensoru tīklu simulatora rīkus, kurus izmanto protokolu izstrādē. Papildus tam, mērķis ir arī izveidot un notestēt savu maršrutēšanas protokolu, kas paredz ziņas piegādes iespējamību konkrētajam mezglam un maršrutēšanas izvēlei izmanto dienu, laika periodu un šo paredzēto vērtību. Bezvadu sensoru tīklos galvenā problēma vienmēr ir bijusi enerģijas patēriņš, tāpēc ar šāda protokola palīdzību mērķis ir samazināt tīklā apraidāmo ziņojumu skaitu, tādā vei…