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101.
Christophe Dematte?¨ Nicolas Molinari Jean-Pierre Daurès 《Computational statistics & data analysis》2007,51(8):3931-3945
An original method is proposed for spatial cluster detection of case event data. A selection order and the distance from the nearest neighbour are attributed to each point, once pre-selected points have been taken into account. This distance is weighted by the expected distance under the uniform distribution hypothesis. Potential clusters are located by modelling the multiple structural change of the distances on the selection order and the best model (containing one or several potential clusters) is selected using the double maximum test. Finally a p-value is obtained for each potential cluster. With this method multiple clusters of any shape can be detected. 相似文献
102.
George Isabella; Vernier Baptiste; Richard Jean-Pierre; Hausberger Martine; Cousillas Hugo 《Canadian Metallurgical Quarterly》2004,118(3):597
Although evidence exists for a lateralization of song production, few studies have focused on the perceptual aspect of lateralization in songbirds. In the present study, the authors recorded neuronal responses to a variety of species-specific and artificial, nonspecific stimuli in both hemispheres of awake and anesthetized male starlings (Sturnus vulgaris). Recordings were made in the primary auditory area of the songbird brain, the Field L complex. The right hemisphere exhibited significantly more responsive units than the left hemisphere in awake birds, and this difference was significantly reduced in anesthetized birds. Furthermore, clear hemispheric specialization toward categories of behaviorally relevant stimuli and precise parameters of these stimuli were found. The main auditory area of the starling's brain thus appears to show some degree of lateralization. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Theoretical coupling efficiency between a channel waveguide and a single-mode optical fibre using a ball lens is optimized by varying the parameters of the optical system such as the relative position of the components, the refractive index and the size of the lens. A specific software has been used for the optimization. Numerical calculations have been done under the Gaussian approximation of the fields distributions. The losses due to waveguides misalignments with respect to their ideal position have been evaluated. All these theoretical results are compared with those obtained from buttcoupling. 相似文献
104.
通过灌浆管钻孔可以获得有助于后期隧道建设的辅助性岩土信息。以海上勘探技术为基础发展起来的陆上钻孔测量系统(instrumenteddrillingsystem)已经通过了实地岩土勘探的检验。该系统通过在设备液压回路(hydrauliccircuits)的不同位置安装一组压力传感器,检测其分辨地层的能力。从理论上讲,随着灌浆钻孔的逐层深入,本方法可以应用于几乎所有土壤类型的生成变化的定性解析(qualitativeinterpretation)。鉴于此法的取样间隔较小,约5mm,所以能够分析为传统实地勘测方法所忽略的岩土结构局部变化。本次研究分别在伦敦的坎宁顿公园(KenningtonPark)和朱比利地铁延长线(JubileeLineEx tension)两地对上述系统进行了实地检验,并在之后对从该系统得到的分析结果与获得的岩心样本进行了比对研究。我们对钻机的零部件以及钻孔方法的选择进行了研究和标准化,以便将来获得全球适用的有意义的数据。此外,通过对几组标准化和非标准化的钻孔设备和方法进行交叉相关分析,我们还量化了不一致的钻孔设备和方法对数据质量的影响程度。 相似文献
105.
Experimental study of heat transfer in oscillating flow 总被引:2,自引:0,他引:2
Pascale Bouvier Jean-Pierre Bardon 《International Journal of Heat and Mass Transfer》2005,48(12):2473-2482
This paper describes an experimental study of heat transfer in oscillating flow inside a cylindrical tube. Profiles of temperature are taken inside the wall and in the fluid from an instrumented test rig, in different conditions of oscillating flow. Profiles obtained allow the observation of the wall effect on heat transfer. A method using the inverse heat conduction principle allows the characterization of local heat transfers at the fluid-solid interface. Finally, a comparison between global and local approaches of heat transfer shows the difficulty of defining a dimensionless heat flux density to model local heat transfer in oscillating flow. 相似文献
106.
In this paper we describe a new function to determine the number of electrons transferred by alloying. HF, the new function proposed, is given by the difference of the partial enthalpies of the two constituents, i.e. HF = h(i) - h(j) - h(i)o and is called the Fermi enthalpy. It is retrieved from data calorimetrically measured. In some way, it describes the change in the enthalpic part of the Fermi energy on alloying. This function is determined for Pd + Ga, Pd + In, Ni + Ga, Ni + In, Pt + In, Au + Al and Ag + Al. The corresponding number of electrons transferred is calculated on stoichiometric considerations. 相似文献
107.
Stimulating Cooperation in Self-Organizing Mobile Ad Hoc Networks 总被引:24,自引:0,他引:24
In military and rescue applications of mobile ad hoc networks, all the nodes belong to the same authority; therefore, they are motivated to cooperate in order to support the basic functions of the network. In this paper, we consider the case when each node is its own authority and tries to maximize the benefits it gets from the network. More precisely, we assume that the nodes are not willing to forward packets for the benefit of other nodes. This problem may arise in civilian applications of mobile ad hoc networks. In order to stimulate the nodes for packet forwarding, we propose a simple mechanism based on a counter in each node. We study the behavior of the proposed mechanism analytically and by means of simulations, and detail the way in which it could be protected against misuse. 相似文献
108.
Jean-Pierre Timmermans Dirk Adriaensen 《电子显微学报》2001,20(1):1-10
1.IntroductionOverthelastfourdecades,fluorescencemicroscopyhasexperiencedatremendousinnovat-ingevolutionandisnowadaysawellestablishedtechniqueinmanyareasofbiomedicalre-search.Inaddition,fluorescencemicroscopicalimaginghasprovenanessentialtoolforstudy-ingbothcellstructureanddynamicprocessestakingplacewithinonecellorbetweenneigh-bouringcells.Thepresentshortreviewwillfocusonthemostrecentdevelopmentsinthisfieldofmicroscopy.2.ConventionalfluorescencemicroscopyTheterm“fluorescence”denotestheprope… 相似文献
109.
Jean-Pierre Guin Tanguy Rouxel Jean-Christophe Sanglebuf Isabelle Melscoët Jacques Lucas 《Journal of the American Ceramic Society》2002,85(6):1545-1552
Ge–Se chalcogenide glasses are characterized by relatively low hardness (0.39–2.35 GPa) and low fracture toughness (0.1–0.28 MPa·m1/2 ). Actually, the hardness of chalcogen-rich glasses is low enough so that the brittleness parameter, B = H / K c , is lower than that of silicate glasses. Whereas hardness and Young's modulus increase with increasing germanium contents, fracture toughness follows a trend similar to that of the density and exhibits a maximum for the Ge20 Se80 composition, which corresponds to the rigidity percolation threshold. Optical microscopy and atomic force microscopy observations suggest that the indentation deformation proceeds by a localized shear deformation phenomenon. Glasses in the chalcogen-rich region behave viscoelastically at room temperature. As a consequence, an increase of the loading time results in a decrease of hardness and toughness. 相似文献
110.
Jean-Pierre Larpin Jean-Claude Colson Denise Delafosse 《Materials Research Bulletin》1976,11(6):713-719
The sulfurisation of cuprous bromides and iodides in hydrogen sulfide, at low pressure, leads to the formation of a porous chalcosine layer, as already investigated in the case of chlorides. The step which fixes the conversion rate is the diffusion of the gaseous reagents in the pores of the sulfide formed. Experimental activation energies are 15 and 34 kcal.Mole?1 respectively, at every step of the reaction. 相似文献