6,174 research outputs found
From carbon nanotubes and silicate layers to graphene platelets for polymer nanocomposites
In spite of extensive studies conducted on carbon nanotubes and silicate layers for their polymer-based nanocomposites, the rise of graphene now provides a more promising candidate due to its exceptionally high mechanical performance and electrical and thermal conductivities. The present study developed a facile approach to fabricate epoxy–graphene nanocomposites by thermally expanding a commercial product followed by ultrasonication and solution-compounding with epoxy, and investigated their morphologies, mechanical properties, electrical conductivity and thermal mechanical behaviour. Graphene platelets (GnPs) of 3.5
Improved Fair-Zone technique using Mobility Prediction in WSN
The self-organizational ability of ad-hoc Wireless Sensor Networks (WSNs) has
led them to be the most popular choice in ubiquitous computing. Clustering
sensor nodes organizing them hierarchically have proven to be an effective
method to provide better data aggregation and scalability for the sensor
network while conserving limited energy. It has some limitation in energy and
mobility of nodes. In this paper we propose a mobility prediction technique
which tries overcoming above mentioned problems and improves the life time of
the network. The technique used here is Exponential Moving Average for online
updates of nodal contact probability in cluster based network.Comment: 10 pages, 7 figures, Published in International Journal Of Advanced
Smart Sensor Network Systems (IJASSN
EMEEDP: Enhanced Multi-hop Energy Efficient Distributed Protocol for Heterogeneous Wireless Sensor Network
In WSN (Wireless Sensor Network) every sensor node sensed the data and
transmit it to the CH (Cluster head) or BS (Base Station). Sensors are randomly
deployed in unreachable areas, where battery replacement or battery charge is
not possible. For this reason, Energy conservation is the important design goal
while developing a routing and distributed protocol to increase the lifetime of
WSN. In this paper, an enhanced energy efficient distributed protocol for
heterogeneous WSN have been reported. EMEEDP is proposed for heterogeneous WSN
to increase the lifetime of the network. An efficient algorithm is proposed in
the form of flowchart and based on various clustering equation proved that the
proposed work accomplishes longer lifetime with improved QOS parameters
parallel to MEEP. A WSN implemented and tested using Raspberry Pi devices as a
base station, temperature sensors as a node and xively.com as a cloud. Users
use data for decision purpose or business purposes from xively.com using
internet.Comment: 6 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:1409.1412 by other author
Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey
Wireless sensor networks (WSNs) consist of autonomous and resource-limited
devices. The devices cooperate to monitor one or more physical phenomena within
an area of interest. WSNs operate as stochastic systems because of randomness
in the monitored environments. For long service time and low maintenance cost,
WSNs require adaptive and robust methods to address data exchange, topology
formulation, resource and power optimization, sensing coverage and object
detection, and security challenges. In these problems, sensor nodes are to make
optimized decisions from a set of accessible strategies to achieve design
goals. This survey reviews numerous applications of the Markov decision process
(MDP) framework, a powerful decision-making tool to develop adaptive algorithms
and protocols for WSNs. Furthermore, various solution methods are discussed and
compared to serve as a guide for using MDPs in WSNs
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