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71.
Sebastien Destercke 《国际智能系统杂志》2011,26(5):426-443
Information is said to be bipolar when it has a positive and a negative part. The problem of representing and processing such bipolar information has recently received a lot of attention in uncertainty theories. In this paper, we are concerned with the representation of asymmetric bipolarity, i.e., with situations where positive and negative information are unrelated and processed in parallel. In this latter case, positive information consists of observations of experiment results, showing what values are possible, whereas negative information consists of constraints (e.g., provided by an expert), restricting the range of possible variable values. Up to now, there are no proposition as to how such bipolar information can be treated in the framework of imprecise probability theory, i.e., when information is represented by convex sets of probabilities. In this paper, we propose the basis of such a framework and provide some illustrative examples. © 2011 Wiley Periodicals, Inc. 相似文献
72.
Mingxin Huang Olivier Bouaziz David Barbier Sebastien Allain 《Journal of Materials Science》2011,46(23):7410-7414
In this article, a physical model describing the deformation behaviour of Twinning Induced Plasticity (TWIP) steels has been
extended to include the effect of carbon content. The experimental validation and the analysis show that carbon mainly controls
the maximum number of dislocations piled up at the twin boundary, resulting in the increase of back-stresses (i.e. kinematic
hardening) and therefore the work hardening rate. This explanation seems to be in agreement with recent TEM observations. 相似文献
73.
74.
Craster RV Kaplunov J Nolde E Guenneau S 《Journal of the Optical Society of America. A, Optics, image science, and vision》2011,28(6):1032-1040
The counterintuitive properties of photonic crystals, such as all-angle negative refraction (AANR) [J. Mod. Opt.34, 1589 (1987)] and high-directivity via ultrarefraction [Phys. Rev. Lett.89, 213902 (2002)], as well as localized defect modes, are known to be associated with anomalous dispersion near the edge of stop bands. We explore the implications of an asymptotic approach to uncover the underlying structure behind these phenomena. Conventional homogenization is widely assumed to be ineffective for modeling photonic crystals as it is limited to low frequencies when the wavelength is long relative to the microstructural length scales. Here a recently developed high-frequency homogenization (HFH) theory [Proc. R. Soc. Lond. A466, 2341 (2010)] is used to generate effective partial differential equations on a macroscale, which have the microscale embedded within them through averaged quantities, for checkerboard media. For physical applications, ultrarefraction is well described by an equivalent homogeneous medium with an effective refractive index given by the HFH procedure, the decay behavior of localized defect modes is characterized completely, and frequencies at which AANR occurs are all determined analytically. We illustrate our findings numerically with a finite-size checkerboard using finite elements, and we emphasize that conventional effective medium theory cannot handle such high frequencies. Finally, we look at light confinement effects in finite-size checkerboards behaving as open resonators when the condition for AANR is met [J. Phys. Condens. Matter 15, 6345 (2003)]. 相似文献
75.
76.
Peter Sjvall Sebastien Gregoire William Wargniez Lisa Skedung Gustavo S. Luengo 《International journal of molecular sciences》2022,23(22)
The crucial barrier properties of the stratum corneum (SC) depend critically on the design and integrity of its layered molecular structure. However, analysis methods capable of spatially resolved molecular characterization of the SC are scarce and fraught with severe limitations, e.g., regarding molecular specificity or spatial resolution. Here, we used 3D time-of-flight secondary ion mass spectrometry to characterize the spatial distribution of skin lipids in corneocyte multilayer squams obtained by tape stripping. Depth profiles of specific skin lipids display an oscillatory behavior that is consistent with successive monitoring of individual lipid and corneocyte layers of the SC structure. Whereas the most common skin lipids, i.e., ceramides, C24:0 and C26:0 fatty acids and cholesteryl sulfate, are similarly organized, a distinct 3D distribution was observed for cholesteryl oleate, suggesting a different localization of cholesteryl esters compared to the lipid matrix separating the corneocyte layers. The possibility to monitor the composition and spatial distribution of endogenous lipids as well as active drug and cosmetic substances in individual lipid and corneocyte layers has the potential to provide important contributions to the basic understanding of barrier function and penetration in the SC. 相似文献
77.
We present the first quantitative experiment on the equilibrium shape of crystals under nonhydrostatic stress. By studying very pure helium-4 crystals, evidence was obtained that small nonhydrostatic stresses produce a macroscopic melting, as predicted by calculations based on elastic theory [1]. Furthermore, above a certain threshold in strain, large grooves appear on the crystal surface, in agreement with the instability first predicted by Grinfeld [2]. Our results also agree with a more qualitative study done by M. Thiel et al.[3]. We finally discuss the relaxation of stresses as a possible consequence of the motion of crystal defects. 相似文献
78.
Doriane Del Frari Sebastien Diliberto Nicolas Stein Clotilde Boulanger Jean-Marie Lecuire 《Journal of Applied Electrochemistry》2006,36(4):449-454
(Bi1-xSbx)2Te3 thermoelectric thin films were deposited on stainless steel discs in 1 M perchloric acid and 0.1 M tartaric acid by pulse electrodeposition in order to optimize the grain growth. The influence of the electrolyte composition,
the cathodic current density and the cathodic pulse time on film stoichiometry were studied. The results show that it is necessary
to increase the Sb content in the electrolyte to obtain the (Bi0.25Sb0.75)2Te3 film stoichiometry. Pulse plating reduced the grain size and the roughness, compared with continuous plating. Thermoelectric
and electrical properties were also studied and it was found that the Seebeck coefficient and electrical resistivity were
related to two parameters: the cathodic pulse current density and the films thickness. 相似文献
79.
An Above-Elbow Prosthesis Employing Programmed Linkages 总被引:1,自引:0,他引:1
Gibbons David T. O''riain Micheal D. Philippe-Auguste Sebastien 《IEEE transactions on bio-medical engineering》1987,(7):493-498
The use of EMG signals from residual muscles to control an above-elbow prosthesis has been tried, but presents many problems, not the least being that the prosthesis is under open-loop control. A more satisfactory control technique is extended physiological proprioception where the inherent proprioceptive feedback present within an intact joint is used to provide closed-loop control. We have developed a prototype of a self-contained above-elbow prosthesis which has electric-powered wrist and elbow joints controlled by an Intel 8751 microcomputer. Our technique is to control the positioning of this above-elbow prosthesis using the motion of the intact shoulder. Grasp, which does not involve positioning in space, is separately controlled using EMG signals from biceps and triceps muscles. The relationship between output (wrist and elbow positions) and input (shoulder position) can be set according to a program or linkage stored in the microcomputer memory. A choice from a range of linkages can enable the user to perform different tasks in different situations. We have verified experimentally that after an amputee has learned to associate the position of the wrist and elbow joints of the prosthesis with his shoulder position, the prosthesis will become a very useful aid. Also, because of the repeatability of operation and the inherent closed-loop nature of the prosthesis, the amputee will be motivated to wear it every day. 相似文献
80.
Ferry A Dugravot S Delattre T Christides JP Auger J Bagnères AG Poinsot D Cortesero AM 《Journal of chemical ecology》2007,33(11):2064-2077
Dimethyl disulfide (DMDS) was identified as a major volatile constituent of Brassica napus roots heavily infested by Delia radicum, the cabbage root fly. Attractiveness of this widespread compound was tested in the field in a naturally complex odorous
environment. By using an original setup especially designed for ground dwelling beetles, different concentrations of the pure
molecule as well as attractiveness of the natural blend emitted by the rotten part of infested roots were tested simultaneously.
The use of general linear model (GLM) statistics permitted us to finely discriminate the responses among the different treatments.
The main predators of D. radicum (i.e., two staphylinids Aleochara bilineata and Aleochara bipustulata and carabid beetles of the genus Bembidion) were significantly attracted by DMDS, but responded in different ways to the natural blend and to the different concentrations
tested. The dose–response curves were similar for the two staphylinids. However, whereas A. bilineata was more attracted by the natural volatile blend than by its preferred DMDS concentration, A. bipustulata was attracted as much by the natural blend as by its preferred DMDS concentration. Carabid beetles exhibited a different
response. They were not attracted by the natural blend, but responded to a wider range of DMDS concentrations that included
low concentrations that did not attract the staphylinid beetles. These results are discussed according to the potential resources
searched by each taxon studied and their specificity for the resources. The possible use of DMDS for enhancing biological
control of D. radicum is mentioned. 相似文献