Search results for "FDM"

On improving the accuracy of Visible Light Positioning system using deep autoencoder

2020

International audience; DC-biased optical Orthogonal Frequency DivisionMultiplexing (DCO-OFDM)-based visible light positioning (VLP)technology along with the Received Signal Strength(RSS) po-sitioning algorithm is widely used to achieve centimeter levelpositioning accuracy for incoming 5G era, especially indoorenvironment. However, the DCO-OFDM has the peak-to-averagepower ratio (PAPR) issue which imposes the nonlinear distortionand it will directly affect the positioning accuracy in the VLPsystem. The PAPR reduction scheme is urgently needed. There-fore, in this paper, the impact of PAPR reduction scheme onpositioning accuracy is investigated. The positioning accuracywith and without the s…

Analysis and performance of FBMC techniques with application to relay networks

2014

Green Composites Based on Hedysarum coronarium with Outstanding FDM Printability and Mechanical Performance

2022

The addition of natural scraps to biodegradable polymers has gained particular interest in recent years, allowing reducing environmental pollution related to traditional plastic. In this work, new composites were fabricated by adding 10% or 20% of Hedysarum coronarium (HC) flour to Poly (lactic acid) (PLA). The two formulations were first produced by twin screw extrusion and the obtained filaments were then employed for the fabrication of composites, either for compression molding (CM) or by fused deposition modeling (FDM), and characterized from a morphological and mechanical point of view. Through FDM it was possible to achieve dense structures with good wettability of the filler that, on…

Hedysarum coronarium-Based Green Composites Prepared by Compression Molding and Fused Deposition Modeling

2022

In this work, an innovative green composite was produced by adding Hedysarum coronarium (HC) flour to a starch-based biodegradable polymer (Mater-Bi®, MB). The flour was obtained by grinding together stems, leaves and flowers and subsequently sieving it, selecting a fraction from 75 μm to 300 μm. Four formulations have been produced by compression molding (CM) and fused deposition modeling (FDM) by adding 5%, 10%, 15% and 20% of HC to MB. The influence of filler content on the processability was tested, and rheological, morphological and mechanical properties of composites were also assessed. Through CM, it was possible to obtain easily homogeneous samples with all filler amounts.…

Spectrum and energy efficient solutions for OFDMA collaborative wireless networks

2013

FLUMO: FLexible Underwater MOdem

2019

The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …

Green Composites Based on Mater-Bi® and Solanum lycopersicum Plant Waste for 3D Printing Applications

2023

3D printability of green composites is currently experiencing a boost in importance and interest, envisaging a way to valorise agricultural waste, in order to obtain affordable fillers for the preparation of biodegradable polymer-based composites with reduced cost and environmental impact, without undermining processability and mechanical performance. In this work, an innovative green composite was prepared by combining a starch-based biodegradable polymer (Mater-Bi®, MB) and a filler obtained from the lignocellulosic waste coming from Solanum lycopersicum (i.e., tomato plant) harvesting. Different processing parameters and different filler amounts were investigated, and the obtained sample…

One-Pot Synthesis, X-ray Single Crystal and Molecular Insight of Enaminone-Based β-Morpholino-/N-Methylpiperazinyl-/Pyrrolidinylpropiophenone

2020

One-pot synthesis of three enaminones, (E)-1-(4-chlorophenyl)-3-morpholinoprop-2-en-1-one 1, (E)-1-(4-chlorophenyl)-3-(4-methylpiperazin-1-yl)prop-2-en-1-one 2, and (E)-1-(4-chlorophenyl)-3-(pyrrolidin-1-yl)prop-2-en-1-one 3 were achieved. The synthetic protocol via three components reaction of p-chloroacetophenone with DMFDMA (N,N-dimethylformamid-dimethylacetal) and the corresponding secondary amines (morpholine/N-methylpiperazine/pyrrolidine) in dioxane under heating for 2.5–4 h at 102 °C yielded the requisite enaminones. This protocol has the advantage of no separation of intermediate, no need for column purification with quantitative yield for the target compounds. The chemical feature…

Synthesis and application of orthogonal signal bases possessing enhanced timefrequency localization for mobile wireless networks

2012

On the evaluation of an optical OFDM radio over FSO system with IM-DD for high-speed indoor communications

2017

En aquest article es proposa un nou sistema híbrid de ràdio sobre fibra (RoF) i òptica d’espai lliure (FSO) basat en la transmissió de senyals òptics OFDM (OOFDM) per proporcionar enllaços de comunicació sense fils òptics d’alta capacitat. Es proposa un esquema de transmissió de baix cost basat en IM-DD per simplificar i reutilitzar la infraestructura existent per desplegar un enllaç FSO d’alt ample de banda. Aquest article mostra els resultats experimentals basats en la implementació de l'esquema proposat sota una transmissió digital OOFDM de 16 QAM a través de 10 km de fibra monomode (SMF) i enllaç FSO de 300 mm. Els resultats mostren la viabilitat de desplegar un sistema de comunicació d…