International Professional University of Technology in Nagoya Repository
Not a member yet
15131 research outputs found
Sort by
Synthesis, structural, optical and morphological characterization ofhematite through the precipitation method: Effect of varying thenature of the base
No full textInternational audienceIron oxide (a-Fe2O3) nanoparticles were synthesized using the precipitation synthesis method focusingonly on (FeCl3, 6H2O), NaOH, KOH and NH4OH as raw materials. The impact of varying the nature of thebase on the crystalline phase, size and morphology of a-Fe2O3 products was explored. XRD spectrarevealed that samples crystallize in the rhombohedral (hexagonal) system at 800 C.The TransmissionElectron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to detect themorphology of synthesized nanoparticles and specify their sizes.However, the Fourier Transform Infra-Red (FT-IR) spectroscopy has permitted the observation of vibrationband Fe-O. Raman spectroscopy was used not only to prove that we have synthesized hematitebut also to identify their phonon modes. The Thermo Gravimetric Analysis (TGA) findings allow thethermal cycle determination of samples whereas Differential Thermal Analysis (DTA) findings allow thephase transition temperature identification. Besides, the optical investigation revealed that samples havean optical gap of about 2.1 eV. Findings highlight that the nature of the agent precipitant plays a significantrole in the morphology of the products and the formation of the crystalline phase. Hematitesynthesis with the base NH4OH brought about much stronger, sharper and wider diffraction peaks of a-Fe2O3. The morphology of samples are spherical with a size of about 61 nm while the size of thenanoparticles of hematite which we have synthesized with NaOH and KOH is respectively of the order of82 and 79 nm
Projected Alternating Direction Method of Multipliers for Hybrid Systems
No full textInternational audienceIn large-scale control optimization problems, a decentralized control structure can offer great scalability and rapidity advantages over a centralized implantation. Alternating Direction Method of Multipliers (ADMM) is a decentralized optimization algorithm which has the important benefit of being quite general in its scope and applicability in continuous systems. In this paper, a new projected ADMM algorithm is defined and it can work in hybrid systems. The key point is to add a convexification and a projection process during each iteration of ADMM algorithm. We have applied it to a charging control problem of electric vehicles. Simulation results show that the proposed algorithm can converge to a similar result as a centralized control within a limited iteration time. Due to its availability, simplicity and scalability, the projected ADMM algorithm may be attractive in some practical engineering application
Tunable Schiffman Phase Shifter for Continuous Beam Steering Antenna
No full textInternational audienceThis paper proposes a compact and tunablephase shifter based on Schiffman topology for beam steeringantenna in Ku band. The achievement of the tunability iscarried out by placing capacitors on the phase shifter tocontrol the phase shift variation. For this, two configurationshave been developed and optimized with ADS softwaresimulator, the first used two capacitors and the second usedthree capacitors. By adjusting the capacitances, the phaseshifters provides a continuously tunable phase shift of 70.66°and 94.4° at 12.7 GHz in two and three compensatedcapacitors structure, respectively. The phase shiftercompensated with two and three capacitances is able to achievea beam steering angle of 14° and 20°, respectively. Simulationsresults show a good performance with excellent phase shiftcharacteristics over a wide bandwidth
Greyscale Image Vectorization from Geometric Digital Contour Representations
No full textInternational audienceIn the field of digital geometry, numerous advances have been recently made to efficiently represent a simple polygonal shape; from dominant points of a curvature-based representation, a binary shape is efficiently represented even in presence of noise. In this article, we exploit recent results of such digital contour representations and propose an image vectorization algorithm allowing a geometric quality control. All the results presented in this paper can also be reproduced online
Experimental assessment of qualitative microwave imaging using a 3-D realistic breast phantom
No full textInternational audienc
An application of the KMT construction to the pathwise weak error in the Euler approximation of one-dimensional diffusion process with linear diffusion coefficient
No full textInternational audienceIt is well known that the strong error approximation in the space of continuous paths equipped with the supremum norm between a diffusion process, with smooth coefficients, and its Euler approximation with step 1/n is O(n−1/2) and that the weak error estimation between the marginal laws at the terminal time T is O(n−1). An analysis of the weak trajectorial error has been developed by Alfonsi, Jourdain and Kohatsu-Higa [Ann. Appl. Probab. 24 (2014) 1049–1080], through the study of the p-Wasserstein distance between the two processes. For a one-dimensional diffusion, they obtained an intermediate rate for the pathwise Wasserstein distance of order n−2/3+ε. Using the Komlós, Major and Tusnády construction, we improve this bound assuming that the diffusion coefficient is linear and we obtain a rate of order logn/n
Definition of requirements for accessing multilingual information opinions
No full textInternational audienceIn this paper, we will present a study concerning the understanding of the needs of people using Internet in order to access to multilingual information. In fact, in the framework of AMIS (Accessing Multilingual Information and opinionS), a Chist-Era project, we propose to develop a system which will help to understand the main idea of a video in a foreign language. In order to design a useful system, a survey allowing to specify the profile of potential users of AMIS has been conducted. The study concerned 170 people from different countries: Poland, Spain and France. The sample is composed of people of different ages and different culture and languages.The results, in terms of requirements, achieved from this study show differences depending on how often the people watch the news on TV or review them on the Internet, and on the age of the target group. These concrete results help us in several decisions concerning how to build a realistic architecture of AMIS
Analysis and Automatic Classification of Some Discourse Particles on a Large Set of French Spoken Corpora
No full textInternational audienceIn French, quite a number of words and expressions are frequently used as discourse particles in spoken language, especially in spontaneous speech. The semantic load of these words or expressions differ whether they are used as discourse particles or not. Therefore, the correct identification of their discourse function remains of great importance. In this paper the distribution of the discourse function (or not discourse function), and of the detailed discourse functions of some of these words, is studied on a large set of French corpora ranging from prepared speech (e.g. storytelling and broadcast news) to spontaneous speech (e.g. interviews and interactions between people). The paper is focused on a subset of discourse particles that are recurrent in the considered corpora. The discourse function of a few thousand occurrences of these words have been manually annotated. A statistical analysis of the functions of the words is presented and discussed with respect to the types of spoken corpora. Finally, some statistics with respect to a few prosodic correlates of the discourse particles are presented, as well as some results of automatic classification and detection of the word function (discourse particle or not) using prosodic features
Innovative simplified array design for wireless power transmission
No full textInternational audienceIn this paper, the synthesis of arrays for long-distance wireless power transmission (WPT) based on unconventional architectures is addressed. A subarraying technique based on an enhanced version of the Contiguous Partition Method suitably customized in order to efficiently deal with a WPT scenario is presented, and a Compressive Sensing-based method developed in a multi-task Bayesian framework is proposed for designing sparse WPT arrays. Selected numerical results are reported to highlight the effectiveness of the proposed techniques