Search results for "Engineering sciences"
showing 10 items of 2347 documents
The household location in multicenter urban spaces
1991
In multicenter urban spaces, the household location problem is to find an optimal location taking into account the locations of several economic centers.In this article, we show that the usual model, maximizing a residential utility under a budget spatial constraint, can’t give a satisfactory solution.So, we construct a fuzzy spatial model, including imprecision in consumer’s behavior. This model allows us to find an optimal location in a multicenter urban setting. Then, an empirical study illustrates the performances of the fuzzy model.
A novel hardware accelerator for the HEVC intra prediction
2015
International audience; A novel hardware accelerator for the High Efficiency Video Coding (HEVC) intra prediction is presented in this paper in order to reduce the computation complexity within this standard and to accelerate the concerned calculations. We propose a new pipelined structure that we called Processing Element (PE) to execute all angular modes, and we repeat it in five paths that our architecture composed of. We present also another structure to carry out the Planar mode. This architecture supports all intra prediction modes for all prediction unit sizes. The synthesis results show that our design can run at 213 MHz for Xilinx Virtex 6 and is capable to process real time 120 10…
3D-QSAR study of ligands for a human olfactory receptor
2005
Abstract Only about 350 olfactory receptors (OR) provide a basis for the remarkable ability of humans to recognise and discriminate a large number of odorants. A recent study reports the odorant repertoire of a human class II OR called OR1G1, including both agonists and antagonists. We used these affinity data to perform a 3D molecular modelling study of these ligands using Catalyst/HypoGen software (Catalyst v4.9.1, Accelrys Inc., San Diego, 2004) to propose alignment models for OR1G1 ligands. We obtained a triple-alignment model, which satisfactorily explained the experimental activities and was able both to predict the antagonist effects of some compounds and to identify new potent agoni…
3D-QSAR study of ligands for two human olfactory receptors
2007
National audience
The affect of contact force sensations on user performance in virtual assembly tasks
2007
International audience; Abstract The development of a realistic virtual assemblyenvironment is challenging because of the complexity of the physical processes and the limitation of available VRtechnology. Many research activities in this domain pri-marily focused on particular aspects of the assembly task such as the feasibility of assembly operations in terms of interference between the manipulated parts. The virtualassembly environment reported in this research is focusedon mechanical part assembly. The approach presented ad-dresses the problem of part-to-part contacts during themating phase of assembly tasks. The system describedcalculates contact force sensations by making their inten-s…
Spectral Density Estimate for Stable Processes Observed with an Additive Error
2018
International audience; In this paper, a symmetric alpha stable process where its spectral representation has an additive error is considered. The error is supposed to be constant. A periodogram as estimator of the spectral density and its rate of convergence are given. In order to give an asymptotically unbiased and consistent estimate of the spectral density, this periodogram is smoothed by an adapted spectral window. The rate of convergence is given.
Apertureless scanning near-field optical microscopy: a comparison between homodyne and heterodyne approaches
2006
International audience; In coherent homodyne apertureless scanning near-field optical microscopy (ASNOM) the background field cannot be fully suppressed because of the interference between the different collected fields, making the images difficult to interpret. We show that implementing the heterodyne version of ASNOM allows one to overcome this issue. We present a comparison between homodyne and heterodyne ASNOM through near-field analysis of gold nanowells, integrated waveguides, and a single evanescent wave generated by total internal reflection. The heterodyne approach allows for the control of the interferometric effect with the background light. In particular, the undesirable backgro…
Experimental Sentinel-2 LAI estimation using parametric, non-parametric and physical retrieval methods – A comparison
2015
Abstract Given the forthcoming availability of Sentinel-2 (S2) images, this paper provides a systematic comparison of retrieval accuracy and processing speed of a multitude of parametric, non-parametric and physically-based retrieval methods using simulated S2 data. An experimental field dataset (SPARC), collected at the agricultural site of Barrax (Spain), was used to evaluate different retrieval methods on their ability to estimate leaf area index (LAI). With regard to parametric methods, all possible band combinations for several two-band and three-band index formulations and a linear regression fitting function have been evaluated. From a set of over ten thousand indices evaluated, the …
Modélisation numérique d’impacts à hautes vitesses par la méthode sans maillage Smoothed Particles Hydrodynamics. Application aux micro-impacts dans …
2021
Investigations on the ballistic behaviours of soft tissue materials are significant research in a medical and pharmaceutical framework. They mainly focus on particles penetrating or traveling into the soft materials. For instance, in the needle-free drug delivery, the micro-scale particles as drug powders are injected into skin with high velocity, and several factors should be considered such as the particle diameters, trajectories, and momentum or velocities of projectile in this process. There have been investigated by some experiments, but there is still no study from the numerical insights.The numerical methods are suitable to study these kinds of processes. Although grid-based methods …
Etude et modélisation du comportement des gouttelettes de produits phytosanitaires sur les feuilles de vignes par imagerie ultra-rapide et analyse de…
2013
In the domain of vineyard precision spraying research, one of the most importantobjectives is to minimize the volume of phytosanitary products ejected bya sprayer in order to be more environmentally respectful with more effectivevine leaf treatments. Unfortunaltely, even if lot of works have been carriedout at a parcel scale, mainly on losses caused by drift, less works have beencarried out at the leaf scale in order to understand which parameters influencethe spray quality. Since few years, recent improvements in image processing,sensitivity of imaging systems and cost reduction have increased the interestof high-speed imaging techniques. Analyzing the behavior of droplets afterimpact with…