Search results for "frequency [modulation]"
showing 10 items of 569 documents
Reduced herbicide use does not increase crop yield loss if it is compensated by alternative preventive and curative measures
2018
Herbicide use must be reduced because of environmental and health issues. This raises the question of whether weeds and the resulting crop yield loss will increase. Previous studies analysing relationships between herbicide use intensity, weeds and yield loss suffer from methodological shortcomings in terms of weed flora and farm diversity as well as temporal scales. Here, we collected data on 272 arable cropping systems from one Spanish and six French regions, from farm surveys, the Biovigilance-Flore network, expert opinion, cropping system trials, crop advisors and scientists. Each system was simulated over 27 years and with 10 weather repetitions, using the virtual-field model FlorSys. …
Changes in the frequency of the Weather Regimes over the Euro-Atlantic and Mediterranean sector and their relation to the anomalous temperatures over…
2013
19 pages; International audience; An exercise has been carried out to assess to what extent the Euro-Atlantic Weather Regimes (WR),described from the ERA-interim Reanalysis in the summer season, projects onto a pool of AGCMAMIPsimulations in which sea surface temperatures (SST) are prescribed from observations.Although the model simulations present some biases in the spatial structure and seasonality of WRs,exhibiting also less variability, they are able to capture main WR over the region in summer season:+Middle East –Middle East, +NAO, -NAO. WR paradigm is used to quantify changes in theatmosphere under warmer/colder than normal conditions over the Mediterranean Sea. To addressthis proble…
Descriptive methods based on citation frequency
2010
International audience; The limitations of intensity scoring when describing the odor characteristics of a complex product have been documented in the literature. Wine is indeed aromatically complex. This presentation aims to present another descriptive approach based merely on the presence/absence of odorant notes in wines. To test the interest of this method, we carried out the sensory description of odor for 12 Burgundy Pinot Noir wines by two independent panels, one with an intensity-based method (conventional descriptive analysis, DA) and the other with a citation frequency-based method. Three criteria were compared: similarity of the sensory maps, control of panel performance and prac…
Terahertz Biomedical Imaging: From Multivariate Analysis and Detection to Material Parameter Extraction
2017
Terahertz imaging is an interesting route for biomedical analysis. In particular, cancer imaging is a subject of study for different teams [1,2]. A work is done in Bordeaux in partnership with a hospital to do terahertz analysis of breast tissue. This work is done in reflection with time domain imaging setup with fresh samples. The aim is to accurately assess tumor margins and which could in the future allow a quick validation of the precision of the surgical procedure and know if new surgery should be performed. We have presented in a previous paper [3] the use of automatic methods of image generation with different parameters [4] in order to explore the different contrasts that exist in t…
Reducing pesticide use through crop diversification
2022
Managing pests while reducing pesticide use is a major challenge to improve cropping system sustainability. Crop diversification appears as a promising tool to promote ecosystem services such as pest control (Tamburini et al., 2020; Beillouin et al., 2021). Lechenet et al. (2016) identified crop sequence and crop diversity, among other management practices, as important factors to reduce pesticide use in most French production situations. Crop diversification could allow the reduction of pesticide use at the cropping system level through: i) the introduction of crops with low intrinsic pesticide use (i.e. grassland, sunflower,…) and ii) the disruption of biological cycles of pests and disea…
Equivalence of Open-Loop and Closed-Loop Operation of SAW Resonators and Delay Lines
2019
International audience; Surface acoustic wave (SAW) sensors in the form of two-port resonators or delay lines are widely used in various fields of application. The readout of such sensors is achieved by electronic systems operating either in an open-loop or in a closed-loop configuration. The mode of operation of the sensor system is usually chosen based on requirements like, e.g., bandwidth, dynamic range, linearity, costs, and immunity against environmental influences. Because the limit of detection (LOD) at the output of a sensor system is often one of the most important figures of merit, both readout structures, i.e., open-loop and closed-loop systems, are analyzed in terms of the minim…
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…
Extremely Low Frequency Magnetic Fields Do Not Affect LTP-Like Plasticity in Healthy Humans.
2020
Introduction: Several studies explored, in vitro, the biological effects of extremely low-frequency magnetic fields (ELF-MFs) and reported the induction of functional changes in neuronal activity. In particular, ELF-MFs can influence synaptic plasticity both in-vitro and in animal models. Indeed, some studies reported an increase in long-term potentiation (LTP) whereas others suggested its reduction. However, no specific study has investigated such effect in humans. Aims: To evaluate whether ELF-MFs affect the propensity of the human cortex to undergo LTP-like plasticity. Methods: We designed a randomized, single-blind, sham-controlled, cross-over study on 10 healthy subjects. Cortical plas…
Object Classification Technique for mmWave FMCW Radars using Range-FFT Features
2021
In this article, we present a novel target classification technique by mmWave frequency modulated continuous wave (FMCW) Radars using the Machine Learning on raw data features obtained from range fast Fourier transform (FFT) plot. FFT plots are extracted from the measured raw data obtained with a Radar operating in the frequency range of 77- 81 GHz. The features such as peak, width, area, standard deviation, and range on range FFT plot peaks are extracted and fed to a machine learning model. Two light weight classification models such as Logistic Regression, Naive Bayes are explored to assess the performance. Based on the results, we demonstrate and achieve an accuracy of 86.9% using Logist…
Reconstruction Improvement in Integral Fourier Holography by Micro-Scanning Method
2015
Although integral holography has many promising advantages in the field of 3D imaging, the resolution of reconstructed holographic image is still limited by the insufficient information captured. To improve the reconstruction quality, an integral Fourier holographic imaging method based on micro-scanning of the micro-lens array is proposed in this paper. The micro-scanning of the micro-lens array can increase the sampling rate in spatial frequency domain and the information of the generated Fourier hologram, which will eventually eliminate the overlapping effect in the reconstructed 3D image. Experiments for different micro-scanning modes are carried out to verify the feasibility of the pro…