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A 3d Source Fingerprinting-Based localization System

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Journal of Computer and Communications 2018年第1期6卷 213-218页

作者： Nadia Aloui Kosai Raoof Youssef Serrestou The laboratoire d’acoustique de l’université du mans Le Mans Université Le Mans France

In recent years, indoor localization becomes more and more essential in our daily life thanks to its interesting applications that cover all domains including security, tourism. Unfortunately, the existing outdoor localization systems fails in indoor environment, which has motivated researchers to develop new localization systems that challenge the indoor environments. In our work, we propose a 3d fingerprinting-based localization system that estimates a source position using acoustic signals. The latter has the advantage of being used in almost roaming devices. No dedicated infrastructure is necessary and the existing infrastructures can then be reused for indoor purposes. The proposed system has been evaluated in experimental tests in an area of dimensions 1.5 m * 1.5 m * 2 m when four microphones were placed at known positions and an artificial fan is turned on. Results show that turbulence affects the precision of estimating the source position by 7% for an accuracy of 8.5 cm.

关键词： 3d Sound Signals Fingerprinting Technique Source location System Turbulence

Melt pool monitoring in laser beam melting with two-wavelength holographic imaging

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light(Advanced Manufacturing) 2022年第1期3卷 154-165页

作者： Matthieu Piniard Beatrice Sorrente Gilles Hug Pascal Picart dOTA ONERAUniversitéParis Saclay91123 PalaiseauFrance laboratoire d’Étude des Microstructures ONERA-CNRSUMR 10429 Avenue de la Division Leclerc92320 ChâtillonFrance laboratoire d’acoustique de l’universitédu mans CNRS 6613Institut d’Acoustique-Graduate School(IAGS)Le Mans UniversitéAvenue Olivier Messiaen72085 Le MansFrance

Over the past two decades, laser beam melting has emerged as the leading metal additive manufacturing process for producing small- and medium-size structures. However, a key obstacle for the application of this technique in industry is the lack of reliability and qualification mainly because of melt pool instabilities during the laser-powder interaction, which degrade the quality of the manufactured components. In this paper, we propose multi- wavelength digital holography as a proof of concept for in situ real-time investigation of the melt pool morphology. A two-wavelength digital holographic setup was co-axially implemented in a laser beam melting facility. The solidified aluminum tracks and melt pools during the manufacturing of 316l were obtained with full- field one-shot acquisitions at short exposure times and various scanning velocities. The evaluation of the complex coherence factor of digital holograms allowed the quality assessment of the phase reconstruction. The motion blur was analyzed by scanning the dynamic melt pool.

关键词： laser beam melting Optical diagnostic digital holography Multi-wavelength holography

Path probability for a Brownian motion

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Chinese Science Bulletin 2011年第34期56卷 3736-3740页

作者： lIN Tongling PUJOS Cyril OU CongJie BI WenPing CAlVAYRAC Florent WANG Qiuping Alexandre lUNAM universite ISMANS Laboratoire de Physique Statistique et Systemes Complexes 44 Avenue F.A. Bartholdi 72000 Le Mans France lPEC Universite du Maine Ave. O. Messiaen 72035 Le Mans France College of Information Science and Engineering Huaqiao University Quanzhou 362021 China laboratoire d＇acoustique Universite du Maine Ave. O. Messiaen 72085 Le Mans Cedex 9 France

This work reports on numerical simulations of Brownian motion in the non-dissipative limit. The objective was to prove the existence of path probability and to compute probability values for some sample paths. By simulating a large number of particles moving from point to point under Gaussian noise and conservative forces, we numerically determine that the path probability decreases exponentially with increasing lagrangian action of the paths.

关键词：样本路径布朗运动概率值数值模拟高斯噪声拉格朗日非耗散点对点

Comparative study using MS and XRd of Fe_(80)Al_(20) alloy produced by mechanical alloying

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Science China(Physics,Mechanics & Astronomy) 2013年第8期56卷 1504-1507页

作者： HAdeF F. OTMANI A. GRENèCHE J.M. laboratoire de Recherche sur la Physico-Chimie des Surfaces et Interfaces LRPCSIUniversité 20 Ao t 1955BP 26Route d'El-HaddaiekSkikda 21000Algérie lUNAM Université du MaineInstitut des Molécules et Matériaux du MansIMMM UMR CNRS 628372085 Le MansFrance

An X-ray diffraction and 57Fe MOssbauer effect study of mechanically alloyed Fe80Al20 is presented. X-ray measurements indicate that the disordered bcc α-Fe（A1） solid solution was formed after 2 h of milling, while the analysis of Mrssbauer spectra suggested that total dissolution of aluminium is achieved after 10 h of milling. These differences can be attributed to：（i） rapid nanocrystallization of aluminium and/or （ii） small particles with small amounts of aluminium cannot be detected by the X-ray diffraction technique.

关键词： nanostructured materials Fe-AI alloys mechanical alloying X-ray diffraction M6ssbauer spectrometry

Eliminating Zero-order diffraction in the digital Holography Wavefront Reconstruction with Adjustable Magnification

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Eliminating Zero-order Diffraction in the Digital Holography...

Evolution of a Holocene banner bank controlled by morphodynamics and structural setting of a macrotidal coast: Saint-Brieuc Bay (NW-Europe)

2010亚洲光电子会议全息、衍射光学和应用分会场

作者： TANKAM Patrice PICART Pascal lAUM-laboratoire d’acoustique de l’université du Maine CNRSAvenue Olivier Messiaen72085 LE MANSFrance ENSIM-école Nationale Supérieure d’Ingénieurs du mans rue Aristote72085 LE MANSFrance

The method of digital holography wavefront reconstruction with adjustable magnification is *** there is strong zero-order diffraction interference on the reconstruction plane,three different methods are proposed to eliminate zero-order diffraction interference,and compared through *** experimental results demonstrated that the mean subtracted from a hologram is an effective method.

关键词： digital holography,wavefront reconstruction,zero-order diffraction interference

来源： cnki会议评论

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Geoscience Frontiers 2021年第5期12卷 166-181页

作者： Kalil Traoréa david Menier Erwan Gensac Pascal le Roy Clément lambert Paul Bessin Kevin Pedoja Anne duperret Romain le Gall laboratoire Géoscience Océan UMR 6538CNRSUniversitéBretagne SudCampus de Tohannic56000 VannesFrance laboratoire Géoscience Océan UMR 6538CNRSIUEMUniversitéBretagne Occidentale29280 PlouzanéFrance laboratoire de Planétologie et Géodynamique UMR 6112CNRSLe Mans UniversitéAvenue Olivier Messiaen72085 Le Mans CEDEX 9France laboratoire Morphodynamique Continentale et Côtière UMR 6143CNRSUniversitéCaen Normandiecampus 12-4Rue des Tilleuls14000 Caen cedexFrance laboratoire Ondes et Milieux Complexes UMR 6294CNRSUniversitéLe Havre Normandie53 rue de PronyCS8054076058 Le Havre cedexFrance

The morphology and internal structure of the Horaine Bank(Bay of Saint-Brieuc,NW France)are described based on multibeam echosounder and high-resolution seismic datasets coupled with vibro-core *** Horaine Bank shows large-scale bedforms in the lee of a submerged rocky shoal,which allowed defining it as a Banner *** internal structure of the sandbank reveals four seismic units(U1-U4)on a Cambrian basement(U0).The basal unit U1 is interpreted as reworked lowstand fluvial sediments those infilled micro incised valleys during a rise in sea *** unit is overlain by paleo-coastal barrier sand-spit(U2)whose development was controlled by swell in the context of a rapid rise in sea *** successive prograding unit(U3)is interpreted as flooding deposits in continuity with unit *** unit U4 is characterized by oblique reflectors oriented in two opposite *** last unit,dated post 3500 yr BP,corresponds to migrating dunes superimposed on the bank and observable in the high-resolution bathymetric *** strong correlation between tidal currents and the apparent clockwise migration of dune crests suggests the presence of a tidal gyre controlling the present-day dynamics of most of the Horaine bank *** study proposes a new model for the construction of banner banks characterized by the gradual transition of a sand spit to a banner bank during marine transgression and ensuing hydrodynamic variability.

关键词： Sand banks Banner bank Holocene climate Geomorphology Sea level rise Tidal gyre

On approximation of BSde and multi-step MlE-processes

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Probability, Uncertainty and Quantitative Risk 2016年第1期1卷 86-107页

作者： Yu A.Kutoyants laboratoire Manceau des Mathematiques Universite du Maine Le MansFrance and National Research University“MPEI”MoscowRussia

We consider the problem of approximation of the solution of the backward stochastic differential equations in Markovian *** suppose that the forward equation depends on some unknown finite-dimensional *** approximation is based on the solution of the partial differential equations and multi-step estimator-processes of the unknown *** the model of observations of the forward equation we take a diffusion process with small *** we establish a lower bound on the errors of all approximations and then we propose an approximation which is asymptotically efficient in the sense of this *** obtained results are illustrated on the example of the Black and Scholes model.

关键词： Backward stochastic differential equation Parameter estimation Multi-step MlE-process Small noise Black and Scholes model

limit behaviour of the minimal solution of a BSde with singular terminal condition in the non Markovian setting

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Probability, Uncertainty and Quantitative Risk 2020年第1期5卷 1-24页

作者： dmytro Marushkevych Alexandre Popier laboratoire Manceaude Mathematiques Le Mans UniversiteAvenue Olivier Messiaen72085 Le Mans cedex 9France

We use the functional Ito calculus to prove that the solution of a BSde with singular terminal condition verifies at the terminal time:lim inf_(t→T)Y(t)=ξ=Y(T).Hence,we extend known results for a non-Markovian termi... 详细信息

关键词： Backward stochastic differential equations Functional stochastic calculus Singularity

English and Chinese language frequency time series analysis

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Chinese Science Bulletin 2011年第34期56卷 3717-3722页

作者： deNG WeiBing WANG duJuan lI Wei WANG Qiuping Alexandre lUNAM universitY ISMANS Laboratoire de Physique Statistique et Systemes Complexes 44 Ave. Bartholdi 72000 Le Mans France Complexity Science Center Institute of Particle Physics Central China Normal University Wuhan 430079 China lUNAM universitY Universite du Maine LPEC UMR CNRS 6087 72085 Le Mans France Max-Planck-lnstitutefor Mathematics in the Sciences Leipzig 04103 Germany

English and Chinese language frequency time series (lFTS) were constructed based on an English and two Chinese novels. Methods of statistical hypothesis testing were adopted to test the nonlinear properties of the lFTS. Results suggest the series exhibited non-normal, auto-correlative, and stationary characteristics. Moreover, we found that lFTS follow the power law distributions, and thereby we investigated the fractal structure, long range correlation, and intermittency, which indicated the self-similarity features of lFTS, and also provided hints that human societies are likely to share some universal properties.

关键词：时间序列分析频率语言中文英文统计假设检验非线性特性长程相关性