Search results for "Telecommunication"
showing 10 items of 1769 documents
A Novel Plasmonic Nanoantenna for High Efficiency Energy Harvesting Applications
2020
In this paper, the results of a geometric investigation of plasmonic nanoantennas for energy harvesting applications in terms of field enhancement and available power are presented. Optimum performances are obtained by a particular arrow-shaped bowtie nanoantennas geometry. The novel nanoantenna geometry is here presented. The simulations of the novel nanoantennas made of aluminium, on a three-layers substrate, composed by silicon, silicon oxide, and aluminium, carried out with CST 2018 tool, are reported and compared with the classical bowtie nanoantennas ones. This study can guide both the engineering and the fabrication of plasmonic nanoantennas.
What?s new in intelligent transportation systems?: An overview of European projects and initiatives
2013
This article is a taxonomy of recent intelligent transportation systems (ITS) initiatives/projects in Europe, and it covers nearly all of the main segments of the transportation sector. The purpose is to appraise the milestones that have been reached so far in the area of ITS. Furthermore, this article will help in identifying directions for future research. By highlighting the potential advantages users get through deployed ITS solutions, this article stimulates the interest of users and relevant stakeholders in the uptake of this technology. Finally, it will also serve as a useful resource for those agents of the scientific community who are interested in taking part in the European Commi…
Economie assessments on the use of wired and wireless recharging systems in Italian and European market
2017
The conductive charging method for the electric vehicles is the most widespread, since it is the simplest and has higher returns. In the last years, alternative charging technologies have been investigated. Between these wireless charging systems have been large diffusion and have been commercialized by some manufacturer. Wireless charging systems for electric vehicles have some advantages respect the wired ones, not obliging the user to connect physically the vehicle to the electric charging station. Assuming the efficiency declared by the manufacturer of wireless systems the authors, in this paper, estimate the maximum cost that wireless recharging systems can have to be, however, more fa…
Economic analysis on the use of wired and wireless recharging systems
2017
Wireless charging systems for electric vehicles have some advantages respect the wired ones, not obliging the user to connect physically the vehicle to the electric charging station. However, at the same time, they have disadvantages linked to issues of electromagnetic compatibility and low efficiency. This study considers some scenarios for which both wired and wireless recharging systems can be adopted, with the aim of estimate the efficiency that must be guaranteed by wireless systems, so that its realization could be more favorable with respect to wired one. The estimation is developed by means of classical economic indexes, in the framework of Italian end European markets. Results repo…
LaCoDa: Layered connected topology for massive data centers
2017
One of the fundamental challenges of existing data centers is to design a network that interconnects massive number of servers, and therefore providing an efficient and fault-tolerant routing service to upper-layer applications. Several solutions have been proposed (e.g. FatTree, DCell and BCube), however they either scale too fast (i.e., double exponentially) or too slow. This paper proposes a new data center topology, called LaCoDa, that combines the advantages of previous topologies while avoiding their limitations. LaCoDa uses a small node degree that matches physical restriction for servers, and it also interconnects a large number of servers while reducing the wiring complexity and wi…
Improving the Performance Metric of Wireless Sensor Networks with Clustering Markov Chain Model and Multilevel Fusion
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/783543 Open access The paper proposes a performance metric evaluation for a distributed detection wireless sensor network with respect to IEEE 802.15.4 standard. A distributed detection scheme is considered with presence of the fusion node and organized sensors into the clustering and non-clustering networks. Sensors are distributed in clusters uniformly and nonuniformly and network has multilevel fusion centers. Fusion centers act as heads of clusters for decision making based on majority-like received signal strength (RSS) with comparis…
Adapting Downlink Power in Fronthaul-Constrained Hierarchical Software-Defined RANs
2017
Abstract The proof-of-concept software-defined radio access network (RAN) is not flexible enough due to the inherent delay and the necessity of high-capacity fronthaul links. We are hence motivated to propose a hierarchical software-defined RAN architecture, over which the base stations (BSs) are abstracted into multiple virtual local controllers while these local controllers are administered by a high-level controller. Under such a hierarchical network architecture, we particularly investigate in this paper how to adapt the BS transmit power over a long term according to the network dynamics under the constraints of mobile user queue stability and limited fronthaul capacity. We first formu…
A new proposed cloud computing based architecture for space ground data systems
2018
International audience; Many companies decided to move towards the cloud computing technology in order to manage, monitor and explore huge space data amount in the space ground data systems. The corresponding transition adaptation needs a study to classify each space related service in the appropriate cloud computing service model layer; SaaS, PaaS and IaaS. In this paper, we specify a representation of proposed cloud computing based ground data system architecture for earth observation missions. The proposed architecture takes into consideration the collaboration aspect between multiple space agencies. We evaluate the time, storage and processing performance when using the cloud computing …
Graph Filtering with Quantization over Random Time-varying Graphs
2019
Distributed graph filters can be implemented over wireless sensor networks by means of cooperation and exchanges among nodes. However, in practice, the performance of such graph filters is deeply affected by the quantization errors that are accumulated when the messages are transmitted. The latter is paramount to overcome the limitations in terms of bandwidth and computation capabilities in sensor nodes. In addition to quantization errors, distributed graph filters are also affected by random packet losses due to interferences and background noise, leading to the degradation of the performance in terms of the filtering accuracy. In this work, we consider the problem of designing graph filte…
A trust-based security enforcement in disruption-tolerant networks
2017
We propose an approach to enforce security in disruption- and delay-tolerant networks (DTNs) where long delays, high packet drop rates, unavailability of central trusted entity etc. make traditional approaches unfeasible. We use trust model based on subjective logic to continuously evaluate trustworthiness of security credentials issued in distributed manner by network participants to deal with absence of centralised trusted authorities.