Search results for " Sensor."

Time synchronization enhancements in wireless networks with ultra wide band communications

2022

The emergence of low cost Ultra Wide Band (UWB) transceivers has enabled the implementation of Wireless Sensor Networks (WSN) based on this communication technology. These networks are composed of distributed autonomous low cost nodes (also known as motes) with their own processing unit, memory and communications. Usually these nodes are power-limited and due to the poor performance and quality of their clocks, time synchronization is in the order of milliseconds and in some specific scenarios till microseconds. The integration of commercial UWB transceivers in these nodes can improve the synchronization accuracy. In particular, we focus on WSN nodes based on off-the-shelf commercial produc…

Real-Life Experiments based on IQRF IoT Testbed: From Sensors to Cloud

2018

Master's thesis Information- and communication technology IKT590 - University of Agder 2018 Internet of things (IoT) is the next generation internet technology which connects devices and objects intelligently to control data collected by diverse types of sensors, radio frequency identification and other physical objects. To address the challenges in IoT such as integrating artificial intelligent techniques with IoT concept, developing green IoT technologies and combining IoT and cloud computing, various platforms which support reliable and low power wireless connectivity are required. IQRF is a recently developed platform for wireless connectivity. It provides low power, low speed, reliable…

Capacity and Energy-Consumption Optimization for the Cluster-Tree Topology in IEEE 802.15.4

2011

International audience; 802.15.4 proposes to use a cluster-tree hierar- chy to organize the transmissions in Wireless Sensor Networks. In this letter, we propose a framework to analyze formally the capacity and the energy consumption of this structure. We derive a Mixed Integer Linear Programming (MILP) formulation to obtain a topology compliant with the standard. This formulation provides the optimal solution for the network capacity: this con- stitutes an upper bound for any distributed algorithms permitting to construct a cluster-tree. This framework can also be used to evaluate the capacity and to compare quantitatively different cluster-tree algorithms.

On-body and off-body transmit power control in IEEE 802.15.6 scheduled access networks

2014

Wireless Body Area Networks (WBANs) have received much attention due to the possibility to be used in healthcare applications. For these applications, energy saving is a critical issue, as in many cases, batteries cannot be easily replaced. A transmit power control scheme, able to adapt to the variations of the wireless body channel, will allow consistent energy saving and longer battery life. In this paper we propose a transmit power control scheme suitable for IEEE 802.15.6 narrowband scheduled access networks, in which the transmission power is modulated frame by frame according to a run-time estimation of the channel propagation conditions. A simple and effective line search algorithm i…

Design of energy efficient MAC protocols in wireless sensor networks

2014

Masteroppgave i Informasjons- og kommunikasjonsteknologi IKT590 Universitetet i Agder 2014 Wireless sensor networks (WSNs) have been used in variety of applications such as in military and defense, process control industry and health monitoring applications. In WSNs, sensors are in small size with limited battery capacity and idle listening is a crucial problem which consumes more energy. Duty cycling (DC) is a technique which is used in many medium access control (MAC) protocols to reduce idle listening. In this thesis, we propose an asynchronous DC protocol, namely energy balancing asynchronous cooperative transmission medium access control (EB-ACT-MAC), which balances the remaining energ…

Naive Bayes classier-based fire detection using smartphone sensors

2014

Masteroppgave i Informasjons- og kommunikasjonsteknologi IKT590 Universitetet i Agder 2014 For many years, smoke detectors have been used as the most crucial _re detection sensors.Although smoke detectors do their job very well, they are not perfect and may causefalse or late alarms. This is because they only rely on one of the _re signs which is smoke.Fire has many other signs as well such as heat and light. It also a_ects its environmentalparameters such as temperature and humidity. But typically, buildings are not equippedwith sensors capable of sensing these changes. Recently, a few smartphone manufacturershave added temperature, humidity, and barometer sensors to their products which c…

Stime rigorose di accuratezza e parallassi residue su blocchi acquisiti industrialmente

2004

Off–on BODIPY-based chemosensors for selective detection of Al3+ and Cr3+versus Fe3+ in aqueous media

2014

[EN] Two new off-on BODIPY-based chemosensors that are highly sensitive for trivalent cations in aqueous solutions are described. Compound 2 exhibits selective sensing of Al3+ and Cr3+ versus Fe3+ through two different channels (UV-vis and fluorescence).

Gatherer: an environmental monitoring application based on IPv6 using wireless sensor networks

2013

In this paper, we present an environmental monitoring application based on IPv6 using wireless sensor networks. We show the guidelines to connect this network to internet using the 6LowPAN standard with a real prototype in the evolution of the Internet of Things. We assign a unique IPv6 address to the different nodes motes of the network. Gatherer is based on TinyOS using IPv6 and UDP protocols and allows the data gathering of temperature and relative humidity from the different motes, requesting specific data from individual motes when required, increasing the accuracy of the measures. We compare the performance of our IPv6-based proposed application against others and show the benefits of…

Oxygen consumption of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in resonse to ocean acidification and warming

2022

Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time…