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Journal of Hydrodynamics 2013年第5期25卷 788-804页

作者： TRAN KHANH Toan OUAHSINE Abdellatif NACEUR Hakim EL WASSIFI Karima Laboratoire Roberval Université de Technologie de Compiègne Laboratoire LAMIH Université de Valenciennes Université Cadi Ayyad Faculté des Sciences et Techniques

In this paper, a numerical method based on a coupling between a mathematical model of nonlinear transient ship manoeuvring motion in the horizontal plane and Mathematical Programming （MP） techniques is proposed. The aim of the proposed procedure is an efficient estimation of optimal ship hydrodynamic parameters in a dynamic model at the early design stage. The proposed procedure has been validated through turning circle and zigzag manoeuvres based on experimental data of sea trials of the 190 000- dwt oil tanker. Comparisons between experimental and computed data show a good agreement of overall tendency in manoeuvring traiectories.

关键词： ship manoeuvrability hydrodynamics coefficients nonlinear transient dynamics sensitivity analysis mathematical pro- gramming

A deep semantic segmentation-based algorithm to segment crops and weeds in agronomic color images

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Information Processing in Agriculture 2022年第3期9卷 355-364页

作者： Sovi Guillaume Sodjinou Vahid Mohammadi Amadou Tidjani Sanda Mahama Pierre Gouton Institute of Mathematics and Physical sciences University of Aboney CalaviDangboBenin ImViA UFR Sciences et TechniquesUniversite de BourgogneFranche-ComteDijonFrance

In precision agriculture,the accurate segmentation of crops and weeds in agronomic images has always been the center of *** methods have been proposed but still the clean and sharp segmentation of crops and weeds is a challenging issue for the images with a high presence of *** work proposes a segmentation method based on the combination of semantic segmentation and K-means algorithms for the segmenta-tion of crops and weeds in color *** images of two different databases were used for the segmentation *** the thresholding technique,everything except plants was removed from the ***,semantic segmentation was applied using U-net followed by the segmentation of crops and weeds using the K-means subtractive *** comparison of segmentation performance was made for the proposed method and K-Means clustering and superpixels *** proposed algorithm pro-vided more accurate segmentation in comparison to other methods with the maximum accuracy of equivalent to 99.19%.Based on the confusion matrix,the true-positive and true-negative values were 0.9952 and 0.8985 representing the true classification rate of crops and weeds,*** results indicated that the proposed method successfully provided accurate and convincing results for the segmentation of crops and weeds in the images with a complex presence of weeds.

关键词： Weed coverage Semantic segmentation Convolutional neural network Subtractive clustering algorithm Simple Linear Iterative Clustering (SLIC) K-means

Numerical Modelling Point-to-Plane of Negative Corona Discharge in N_2 Under Non-Uniform Electric Field

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Plasma Science and Technology 2015年第6期17卷 469-474页

作者： A.K.FEROUANI M.LEMERINI L.MERAD M.HOUALEF Ecole Préparatoire en sciences et techniques Département de Physique LPT Université A.BelkaidFaculté des SciencesDépartement de Physique Ecole Préparatoire en sciences et techniques Département de Maths

The paper presents a simulation model of the negative corona discharge in N2 under various pressures. The simulated discharge is of a negative point-to-plane mass type, with an inter-electrode separation distance of 20 mm and a symmetry about the axis of discharge. This simulation investigates the behavior of the neutral density and temperature for different pressures in the range of 0.1-10.0 bar. The spatial and temporal evolution of the neutral gas is analyzed based upon the equations of continuity, momentum and energy in a two-dimensional cylindrical geometry model. For that geometry of the system, the FCT （Flux Corrected Transport） technique was adopted. The results show that the pressure plays a significant role of the neutrals dynamics.

关键词： DC corona discharge FCT method numerical simulation

The Consideration of Overlapping Lines in the Calculation of Radiative Power Emitted from CH_4 Thermal Plasma

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Plasma Science and Technology 2012年第12期14卷 1073-1078页

作者： R. BENALLAL B. LIANI Theoretical Physics Laboratory Abou Bekr Belkaid University cole prparatoire des sciences et techniques

Net emission coefficients of radiation were calculated for isothermal plasma of methane as a function of the plasma temperature 5,000 - 30,000 K and the arc radius 0 mm to 10 mm at atmospheric pressure. Calculations take into account continuum and line radiations, special attention has also been given to the influence of overlapping spectral lines. The line shapes in our calculations are given by convolution of Doppler and Lorentz profiles, resulting in a simplified Voigt profile. In the case of a hydrogen profile, we used the Vidal tables, and the four first Lyman lines and the four first Balmer lines were considered. This calculation was carried out on the assumption of local thermodynamic equilibrium and in a nondiffusive environment. The net emission coefficient calculation for pure argon plasma was compared with the experimental results of Evans in our previous work. We used the escape factor, and our results were higher than those of the experiment. In this paper, we explain why, using the escape factor, the radiation is overestimated. The net emission coefficient obtained from a real spectrum was compared with Essoltani work＇s which used the line-by-line method for pure argon plasma.

关键词： thermal plasma radiation net emission coefficient absorption coefficient

New materials based on carbazole for optoelectronic device applications:Theoretical investigation

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Chinese Chemical Letters 2008年第4期19卷 488-492页

作者： K.Hasnaoui H.Zgou M.Hamidi M.Bouachrine Unité de Recherche sur les Macromolécules et Modélisation Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Chimie Théorique AppiquéeFaculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Chimie Théorique Appliquée Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Recherche sur les Macromolécules et Modélisation Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco

A quantum-chemical investigation on the structural and optoelectronic properties of two materials based on carbazole is carried *** purpose is to display the effect of grafting the fluorine atoms on their optoelectronic and physico-chemical *** addition to solubility in the polar solvents and the modification in geometric parameters,the substitution of fluorine destabilizes the HOMO and LUMO levels,decreases the band gap energy and raises conjugation *** properties suggest the substituted fluorine compound as a good candidate for optoelectronic applications.

关键词： Conjugated polymers DFT theoretical investigation Carbazole Optoelectronic applications

Theoretical study of structural and electronic properties of oligo(thiophene-phenylene)s in comparison with oligothiophenes and oligophenylenes

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Chinese Chemical Letters 2008年第1期19卷 123-126页

作者： H.Zgou S.M.Bouzzine S.Bouzakraoui M.Hamidi M.Bouachrine Unité de Recherche sur les Macromolécules et Modélisation Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Chimie Théorique AppliquéeFaculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Chimie Théorique Appliquée Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco Unité de Recherche sur les Macromolécules et Modélisation Faculté des Sciences et TechniquesB.P.509 Boutalamine5200 ErrachidiaMorocco

In this work, a quantum-chemical investigation on the structural and opto-electronic properties of oligo（thiophene-phenylene）（4TP） is carried out. The results are discussed in comparison with the properties of corresponding oligothiophene （8T） and oligophenylene （8P）. As the opto-electronic properties of this type of conducting polymers are governed by their electronic band gap, we shall also present a comparison among HOMO, LUMO and band gap energies of these three materials.

关键词： Conjugated polymers Oligothiophene Oligophenylene Oligo(thiophene-phenylene) DFT

Design and analysis of a recommendation system based on collaborative filtering techniques for big data

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Intelligent and Converged Networks 2023年第4期4卷 296-304页

作者： Najia Khouibiri Yousef Farhaoui Ahmad El Allaoui STI Laboratory IDMT-IDMSFaculty of Sciences and Techniques ErrachidiaMoulay Ismail UniversityMeknes 5003Morocco

Online search has become very popular,and users can easily search for any movie title;however,to easily search for moving titles,users have to select a title that suits their ***,people will have difficulty choosing the film they want to *** process of choosing or searching for a film in a large film database is currently time-consuming and *** spend extensive time on the internet or on several movie viewing sites without success until they find a film that matches their *** happens especially because humans are confused about choosing things and quickly change their ***,the recommendation system becomes *** study aims to reduce user effort and facilitate the movie research ***,we used the root mean square error scale to evaluate and compare different models adopted in this *** models were employed with the aim of developing a classification model for predicting ***,we tested and evaluated several cooperative filtering *** used four approaches to implement sparse matrix completion algorithms:k-nearest neighbors,matrix factorization,co-clustering,and slope-one.

关键词： recommendation system machine learning collaborative filtering(CF) decision support system big data

The magnetic properties of diluted CoFe_2O_4 nanomaterials

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Chinese Physics B 2012年第4期21卷 513-518页

作者： R.Masrour M.Hamedoun A.Benyoussef Laboratory of Materials ProcessesEnvironment and QualityCady Ayyed UniversityNational School of Applied SciencesRoute Sidi Bouzid-BP 6346000 SafiMorocco LMPHE(URAC 12) Facultédes SciencesUniversitéMohamed V-AgdalRabatMorocco Institute for Nanomaterials and Nanotechnologies RabatMAScIRMorocco Academie HassanⅡdes sciences et techniques RabatMorocco Academie HassanⅡdes sciences et techniques RabatMorocco

The magnetic properties of （Cox Fe1-x）A （Zn1-x Fe1＋x）B O4 are studied using mean-field theory and the probability distribution law to obtain the saturation magnetization, the coercive field, the critical temperature, and the exchange interactions with different values of D （nm） and x. High-temperature series expansions （HTSEs） combined with the Pade approximant are used to calculate the critical temperature of （CoxFe1-x）A（Znl-xFe1＋x）BO4, and the critical exponent associated with magnetic susceptibility is obtained.

关键词： (CoxFe1-x)a(Zn1-xFe1+x)BO4 probability law saturation magnetization coercive field high-temperature series expansions

Bifurcation and Stability Analysis in Complex Cross-Diffusion Mathematical Model of Phytoplankton-Fish Dynamics

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Journal of Partial Differential Equations 2019年第3期32卷 207-228页

作者： OUEDRAOGO Hamidou OUEDRAOGO Wendkouni SANGARE Boureima Universite Nazi BONIf Unite de Formation et de Recherche en sciences et techniques(ufr/ST) Departement de Mathematicjues et Informatiques01 BP 1091 Bobo Dsso 01Burkina Faso

In this paper,we propose a nonlinear reaction-diffusion system describing the interaction between toxin-producing phytoplankton and fish *** analyze the effect of cross-diffusion on the dynamics of the *** mathematical study of the model leads us to have an idea on the existence of a solution,the existence of equilibria and the stability of the stationary ***,numerical simulations performed at two-dimensions allowed us to establish the formation of spatial patterns and a threshold of release of the toxin,above which we talk about the phytoplankton blooms.

关键词： Toxin effect populations dynamics predator-prey model reaction-diffusion system bifurcation pattern formation

Phase preservation of orbital angular momentum of light in multiple scattering environment

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Light(Science & Applications) 2024年第10期13卷 2263-2275页

作者： Igor Meglinski Ivan Lopushenko Anton Sdobnov Alexander Bykov College of Engineering and Physical sciences Aston UniversityBirmingham B47ETUK Optoelectronics and Measurement techniques University of OuluOulu FI-90014Finland

Recent advancements in wavefront shaping techniques have facilitated the study of complex structured light’s propagation with orbital angular momentum(OAM)within various *** introduction of spiral phase modulation to the Laguerre–Gaussian(LG)beam during its paraxial propagation is facilitated by the negative gradient of the medium’s refractive index change over time,leading to a notable increase in the rate of phase twist,effectively observed as phase retardation of the *** approach attains remarkable sensitivity to even the slightest variations in the medium’s refractive index(∼10−6).The phase memory of OAM is revealed as the ability of twisted light to preserve the initial helical phase even propagating through the turbid tissue-like multiple scattering *** results confirm fascinating opportunities for exploiting OAM light in biomedical applications,*** as non-invasive trans-cutaneous glucose diagnosis and optical communication through biological tissues and other optically dense media.

关键词： scattering momentum light