Search results for "Engineering sciences"
showing 10 items of 2347 documents
Surface modifications induced by nanosecond pulsed Nd:YAG laser irradiation of metallic substrates
2006
International audience; Substrate surface preparation is a key step in coating deposition process. In recent years, pulsed laser cleaning has emerged as a possible technique to challenge the traditional preparation methods (based on degreasing and eventually grit-blasting). The laser operated at short-pulse mode offers high cleaning efficiency and therefore has been largely used. In a specific process named PROTAL®, a nanosecond pulsed laser is introduced to prepare the surface simultaneously to thermal spraying, with the purpose of eliminating the contaminants and generating favorite surface conditions for coating deposition. This study aims at clarifying some fundamental aspects of nanose…
Parameters Analysis Influencing 3D Measurement without Contact by Laser Scanner to Make a Compensation Model
2005
International audience; The 3D measurement is more and more important in industrial applications. There are different applications like 3D inspection or reverse engineering. In the both cases, the classical techniques by contact present the advantage of a good accuracy but the costs are expensive because of the slow progress of the measurement. In an other hand, the without contact technologies have a high cadency of points measurement but with a lower accuracy. We present in this study a methodology to estimate the measurement uncertainties and to correct the systematic error. The global error can be separated in random error (in the order of 25 m for the considered laser scanner) and in …
OLF : RGB-D Adaptive Late Fusion for Robust 6D Pose Estimation
2023
RGB-D 6D pose estimation has recently gained significant research attention due to the complementary information provided by depth data. However, in real-world scenarios, especially in industrial applications, the depth and color images are often more noisy. Existing methods typically employ fusion designs that equally average RGB and depth features, which may not be optimal. In this paper, we propose a novel fusion design that adaptively merges RGB-D cues. Our approach involves assigning two learnable weight α 1 and α 2 to adjust the RGB and depth contributions with respect to the network depth. This enables us to improve the robustness against low-quality depth input in a simple yet effec…
Vine leaf roughness estimation by image processing
2013
International audience; The application of plant protection product has an important role in agricultural production processes. With current pesticides management, a huge amount of them are applied to worldwide orchards. In precision spraying, spray application efficiency depends on the pesticide application method, the phytosanitary product as well as the leaf surface properties. For environmental and economic reasons, the global trend is to reduce the pesticide application rate of the few approved active substances. Under these constraints, one of the challenges is to improve the efficiency of pesticide application. Different parameters can influence pesticide application such as nozzle t…
Architecture-Driven Level Set Optimization: From Clustering to Sub-pixel Image Segmentation
2016
Thanks to their effectiveness, active contour models (ACMs) are of great interest for computer vision scientists. The level set methods (LSMs) refer to the class of geometric active contours. Comparing with the other ACMs, in addition to subpixel accuracy, it has the intrinsic ability to automatically handle topological changes. Nevertheless, the LSMs are computationally expensive. A solution for their time consumption problem can be hardware acceleration using some massively parallel devices such as graphics processing units (GPUs). But the question is: which accuracy can we reach while still maintaining an adequate algorithm to massively parallel architecture? In this paper, we attempt to…
Cis-15 intermediates of biohydrogenation in the duodenal flow of cows receiving linseed
2006
Duodenal samples from a previous experiment (Akraim et al., 2006) were reanalysed for determination of cis-15 intermediates of ruminal biohydrogenation (BH). Three dry Holstein cows fitted with a duodenal cannula received a diet with 14% (dry matter basis) raw linseed. C18 fatty acids (C18FA) represented 6.3% of dietary dry matter, and contained 57.8% of C18:3. After 18 days adaptation, on each cow, twelve samples of duodenal flow were taken over 3 days, composited, and analysed for FA composition. Cis-9,trans-11,cis-15C18:3 and trans-11,cis-15C18:2 (CLnA) were identified by GC-MS. The proportion of CLnA was low, in spite of the high C18:3 intake. The first step of C18:3 BH, isomerisation t…
Antioxidant properties of water-soluble gum from flaxseed hulls
2016
International audience; Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL(-1)), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL(-1)), high reducing power capacity (RPSFG = 5 mg·mL(-1)), and po…
Weld pool surface temperature measurement from polarization state of thermal emission
2014
This paper presents a passive polarimetry method using a division of aperture optical device in order to measure the temperature distribution at the weld pool surface. Thermal emission from a hot liquid metal was investigated at a near-infrared wavelength corresponding to a blind spectral window of a helium plasma generated during gas tungsten arc welding process. The refractive index of liquid metal and the surface radiance are deduced from the polarisation state of thermal emissions. Based upon the knowledge of both characteristics, the temperature distribution can be calculated. Conseil Régional de Bourgogne
On the Literature Divergences of the Humanitarian Supply Chain
2015
International audience; The field of humanitarian logistics has evolved rapidly over the past decade, drawing on contributions from the areas of operations research, business engineering, supply chain management, information systems, and computer sciences. Even more varied are the specific problems that are modeled and addressed, ranging monitoring of the supply chain as a whole to decision support for specific sourcing or distribution decisions. While recently, few studies have presented taxonomies and identified research gaps, there is to this date not yet a clear understanding of how the different methodologies and domains shall be combined to achieve a consistent mix of methods and tool…
Near IR stationary wave Fourier transform lambda meter in lithium niobate: multiplexing and improving optical sampling using spatially shifted nanogr…
2021
Several integrated optics solutions currently exist to develop monolithic, robust, and lightweight high-resolution spectrometers for spatial applications. An interesting option is generating a stationary wave inside a single-mode waveguide, and sampling the interference fringes using dielectric discontinuities on the surface of the waveguide. This allows the recording of the signal on a detector on top of the waveguide, and using dedicated Fourier transform methods to recover the spectrum of the source. All the difficulty is then linked to the length of the interferogram that is sampled. This determines the spectral resolution and the spacing between sampling centers, which are ultimately l…