Search results for " electronics"
showing 10 items of 580 documents
Optimal energy management in the smart grid
2017
In this chapter, the problem of energy management in smart grids is outlined. Optimized energy management is considered here as the operation of energy and power flow control in the aim of attaining minimum cost or minimum power losses while meeting technical constraints. Of course, according to the type of energy system in which such operation is carried out, the meaningful variables and objectives in the problem may largely change. As the extension of the system increases, the influence of the physical behaviour of the electrical power lines takes a more important role. Power electronics takes instead an increasing influence, as the dimension of the power system decreases although Kirchho…
Donor/acceptor heterojunction organic solar cells
2017
Organic solar cells (OSCs) have made very good improvements in recent years, reaching power conversion efficiencies above 10% [1]. This have been achieved through chemical synthesis of new organic materials with improved properties and also by new and more or less complex structures such as donor/acceptor (D/A) or bulk heterojunction OSCs. Here we report the results of initial development of OSCs based on the simple D/A heterojunction [2]. Copper phtalocyanine (CuPc) is used as donor organic material, whereas perylenetetracarboxylic dianhydride (PTCDA) and fullerene (C60) as acceptor organic materials. Moreover bathocuproine (BCP) is used as exciton blocking layer. Devices are fabricated by…
Cloaking In-Plane Elastic Waves with Swiss Rolls
2020
We propose a design of cylindrical cloak for coupled in-plane shear waves consisting of concentric layers of sub-wavelength resonant stress-free inclusions shaped as Swiss rolls. The scaling factor between inclusions&rsquo
Comparison between SiC and GaN switching devices in fast-recharging systems for electric vehicles
2023
Recently, the improvement of the semiconductor devices to achieve higher efficiency and higher power density has risen to interest. Si carbide and gallium nitride offer faster switching frequency and lower losses; however, the knowledge of the behaviour of these devices is not mature. In this paper, a system for fast charging of batteries for electric vehicles based on an isolated DC-DC converter equipped with both SiC and GaN devices is presented and an interesting experimental comparison among these two technologies will be given in terms of dynamic performances, electromagnetic compatibility, stability, efficiency, and so on.
A Spatial-Temporal Correlation Approach for Data Reduction in Cluster-Based Sensor Networks
2019
International audience; In a resource-constrained Wireless Sensor Networks (WSNs), the optimization of the sampling and the transmission rates of each individual node is a crucial issue. A high volume of redundant data transmitted through the network will result in collisions, data loss, and energy dissipation. This paper proposes a novel data reduction scheme, that exploits the spatial-temporal correlation among sensor data in order to determine the optimal sampling strategy for the deployed sensor nodes. This strategy reduces the overall sampling/transmission rates while preserving the quality of the data. Moreover, a back-end reconstruction algorithm is deployed on the workstation (Sink)…
Adapting to Dynamic LEO-B5G Systems : Meta-Critic Learning Based Efficient Resource Scheduling
2022
Low earth orbit (LEO) satellite-assisted communications have been considered as one of key elements in beyond 5G systems to provide wide coverage and cost-efficient data services. Such dynamic space-terrestrial topologies impose exponential increase in the degrees of freedom in network management. In this paper, we address two practical issues for an over-loaded LEO-terrestrial system. The first challenge is how to efficiently schedule resources to serve the massive number of connected users, such that more data and users can be delivered/served. The second challenge is how to make the algorithmic solution more resilient in adapting to dynamic wireless environments.To address them, we first…
Installation and commissioning of the TileCal Read-Out Drivers
2007
TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The main component of the TileCal back-end electronics is the Read-Out Driver (ROD). The ROD system is placed between the first and the second level trigger and it is the responsible for processing the data gathered by the detector. The principal devices of the RODs are the Digital Signal Processors (DSPs) mounted in the Processing Units (PUs) daughterboards. The architecture and functionality of the RODs are briefly explained. Then, it is presented the ROD system installation in the ATLAS electronics cavern. Currently, the RODs are being used for the detector commissioning. It is detailed the Detector and Verific…
Signal processing and frequency-dependent associative memory based on nanoswitches
2008
A signal processing concept based on nanoscale switches whose conductance can be tuned by an external stimulus between two (ON and OFF) states is proposed and analyzed theoretically. The building block of the system is formed by a metal nanoparticle linked to two electrodes by an organic ligand and a molecular switch. When we apply an alternating potential to the system of the same frequency as the periodic variation between the ON and OFF states induced on the switch, the net charge delivered by the system exhibits a sharp resonance. This resonance can be used to process an external signal by selectively extracting the weight of the different harmonics. In addition, a frequency-dependent a…
Applying Cathegorical Metrics on Fuzzy Systems
2007
This work analyzes the categorical metrics usage on a very specific subset of Intelligent Systems: Fuzzy Systems. Several characteristics for such systems must be carefully evaluated when metrics and indicators are defined, in order to consider the fuzzy essence as part of the evaluation result. A set of metrics and indicators are defined and applied to the classical inverted pendulum problem. The paper does not intend to provide an exhaustive analysis of the quality evaluation on soft computing problem. It just presents a way to start the study of quality measure in that area.
Polymer-Functionalised Nanograins of Mg-Doped Amorphous Calcium Carbonate via a Flow-Chemistry Approach
2019
Calcareous biominerals typically feature a hybrid nanogranular structure consisting of calcium carbonate nanograins coated with organic matrices. This nanogranular organisation has a beneficial effect on the functionality of these bioceramics. In this feasibility study, we successfully employed a flow-chemistry approach to precipitate Mg-doped amorphous calcium carbonate particles functionalized by negatively charged polyelectrolytes&mdash