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Modelling of sediment movement in the surf and swash zones

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Acta Oceanologica Sinica 2015年第2期34卷 137-142页

作者： TOKPOHOZIN N.B. KOUNOUHEWA B. AVOSSEVOU G.Y.H. HOUEKPOHEHAM A. AWANOU C.N. institut de mathématiques et de sciences physiques (IMSP/UAC) Centre Béninois de la Recherche Scientifique et Technique (CBRST) Laboratoire de Physique du Rayonnement (LPR/FAST-UAC)

Under the action of marine currents,non-cohesive sediments evolve by bed-load,by saltation or suspension depending on their *** authors have considered that the movement of sediment is bidimensional and modelized the effects of swell by a constant velocitynear the *** we have studied the velocity profile of fluctuating currents near the seabed and studied the movement of sediment in *** results show that in the areas of study（surf and swash）the movement of sediment occurs in a volume,and the evolution of sediment varies from an areato *** obtained theoretical profiles of the position and velocity vectors confirm the observations of several authors.

关键词： non-cohesive sediments sediment dynamics swell trajectory of sediment velocity drive

Symmetrically Harmonic Kaluza-Klein Metrics on Tangent Bundles

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Journal of Applied mathematics and Physics 2022年第12期10卷 3548-3561页

作者： Serge degla Leonard Todjihounde institut de mathématiques et de sciences physiques Porto-Novo Benin institut de mathématiques et de sciences physiques Porto-Novo Benin

Let (M, g) be a Riemannian manifold and G be a Kaluza-Klein metric on its tangent bundle TM. A metric H on TM is said to be symmetrically harmonic to G if the metrics G and H are harmonic w.r.t. each other;that is the identity maps id: (TM,G) → (TM,H) and id: (TM,H) → (TM,G) are both harmonic maps. In this work we study Kaluza-Klein metrics H on TM which are symmetrically harmonic to G. In particular, we characterize and determine horizontally and vertically conformal Kaluza-Klein metrics H on TM, which are symmetrically harmonic to G.

关键词： Harmonic Maps Kaluza-Klein Metrics Conformal Metrics

BEST APPROXIMATION FOR WEIERSTRASS TRANSFORM CONNECTED WITH SPHERICAL MEAN OPERATOR

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Acta mathematica Scientia 2012年第2期32卷 455-470页

作者： L.T.Rachdi N.Msehli Département de math'ematiques Facult'e des Sciences de Tunis2092 El-ManarTunisia Département de mathématiques et d'informatique Institut National des Sciences Appliquées et de Technologie de Tunis1080 TunisTunisia

Using reproducing kernels for Hilbert spaces, we give best approximation for Weierstrass transform associated with spherical mean operator. Also, estimates of extremal functions are checked.

关键词： Weierstrass transform spherical mean operator best approximation repro-ducing kernel extremal function

Reconstructing f(T) modified gravity from ECHde and ECNAde models

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Communications in Theoretical Physics 2020年第9期72卷 75-88页

作者： A E Godonou Ines G Salako M J S Houndjo etienne Baffou Joel Tossa institut de mathematiques et de sciences physiques(IMSP) 01 BP 613 Porto-NovoBenin Ecole de Genie Rural(EGR) 01 BP 55 KetouBenin Faculte des sciences et Techniques de Natitingou(FAST) BP 72NatitingouBenin

We investigate alternative candidates to dark energy(de) that can explain the current state of the Universe in the framework of the generalized teleparallel theory of gravity f(T), where T denotes the torsion scalar. To achieve this, we carry out a series of reconstructions taking into account the ordinary and entropy-corrected versions of the holographic and new agegraphic de *** models are used as alternatives to de in the literature in order to describe the current state of our Universe. It is remarked that the proposed models indicate behavior akin to phantom or quintessence models. Furthermore, we also generate the parameters of the equation of state associated with entropy-corrected models and we observe a phase transition between the quintessence state and phantom state as it is shown by the recent observational data. We also investigate the stability of these models and we create the {r-s} trajectories and compare with the ΛCDM limit. The behavior of certain physical parameters such as the speed of sound and the Statefinder diagnostic pair {r-s} is compatible with the current observational data.

关键词： teleparallel gravity ECHde ECNAde

Practical stabilization of a class of uncertain time-varying nonlinear delay systems

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控制理论与应用（英文版） 2009年第2期7卷 175-180页

作者： Bassem Ben HAMED Mohamed Ali HAMMAMI institut Supérieur des sciences Appliquées et de Technologie de Gabès Département de MathématiquesRue Amor Ben El Khatab 6029 GabèsTunisia Faculté des sciences de Sfax Département de Mathématiques BP 802 Route Soukra km 4 Sfax 3018Tunisia

In this paper we deal with a class of uncertain time-varying nonlinear systems with a state delay. Under some assumptions, we construct some stabilizing continuous feedback, i.e. linear and nonlinear in the state, which can guarantee global uniform exponential stability and global uniform practical convergence of the considered system. The quadratic Lyapunov function for the nominal stable system is used as a Lyapunov candidate function for the global system. The results developed in this note are applicable to a class of dynamical systems with uncertain time-delay. Our result is illustrated by a numerical example.

关键词： Nonlinear system Time-delay Feedbacks Practical convergence Lyapunov function

Implementation of Network Intrusion detection System Using Soft Computing Algorithms (Self Organizing Feature Map and Genetic Algorithm)

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Journal of Information Security 2019年第1期10卷 1-24页

作者： Joel T.Hounsou Thierry Nsabimana Jules degila institut de mathématiques et de sciences physiques Porto-NovoBeninUniversitéd’Abomey Calavi

In today’s world, computer network is evolving very rapidly. Most public or/and private companies set up their own local networks system for the purpose of promoting communication and data sharing within the companies. Unfortunately, their data and local networks system are under risks. With the advanced computer networks, the unauthorized users attempt to access their local networks system so as to compromise the integrity, confidentiality and availability of resources. Multiple methods and approaches have to be applied to protect their data and local networks system against malicious attacks. The main aim of our paper is to provide an intrusion detection system based on soft computing algorithms such as Self Organizing Feature Map Artificial Neural Network and Genetic Algorithm to network intrusion detection system. KDD Cup 99 and 1998 DARPA dataset were employed for training and testing the intrusion detection rules. However, GA’s traditional Fitness Function was improved in order to evaluate the efficiency and effectiveness of the algorithm in classifying network attacks from KDD Cup 99 and 1998 DARPA dataset. SOFM ANN and GA training parameters were discussed and implemented for performance evaluation. The experimental results demonstrated that SOFM ANN achieved better performance than GA, where in SOFM ANN high attack detection rate is 99.98%, 99.89%, 100%, 100%, 100% and low false positive rate is 0.01%, 0.1%, 0%, 0%, 0% for DoS, R2L, Probe, U2R attacks, and Normal traffic respectively.

关键词： SOFM Intrusion detection Systems False Positive Rate detection Rate KDD Cup 99 GA

Global strong solutions to 3-D Navier-Stokes system with strong dissipation in one direction dedicated to Professor Jean-Yves Chemin on the Occasion of His 60th Birthday

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Science China mathematics 2019年第6期62卷 1175-1204页

作者： Marius Paicu Ping Zhang institut de mathématiques de Bordeaux Université Bordeaux 1 Academy of mathematics and Systems Science and Hua Loo-Keng Key Laboratory of mathematics Chinese Academy of Sciences School of mathematical sciences University of Chinese Academy of Sciences

We consider three-dimensional incompressible Navier-Stokes equations(NS) with different viscous coefficients in the vertical and horizontal variables. In particular, when one of these viscous coefficients is large enough compared with the initial data, we prove the global well-posedness of this system. In fact, we obtain the existence of a global strong solution to(NS) when the initial data verifies an anisotropic smallness condition which takes into account the different roles of the horizontal and vertical viscosity.

关键词： anisotropic Navier-Stokes equations Littlewood-Paley theory well-posedness

Active Control of Chaotic Oscillations in Nonlinear Chemical Dynamics

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Journal of Applied mathematics and Physics 2019年第3期7卷 547-558页

作者： Dagbégnon Luc Olabodé Batablinlè Lamboni Jean Bio Chabi Orou Laboratoire de Mécanique des Fluides de la Dynamique Nonlinéaire et de la Modélisation des Systèmes Biologiques (LMFDNMSB) institut de mathématiques et de sciences physiques (IMSP) Porto-Novo Bénin institut de mathématiques et de sciences physiques (IMSP) Porto-Novo Bénin

Abstract: This work studies the active control of chemical oscillations governed by a forced modified Van der Pol-Duffing oscillator. We considered the dynamics of nonlinear chemical systems subjected to an external sinusoidal excitation. The approximative solution to the first order of the modified Van der Pol-Duffing oscillator is found using the Lindstedt’s perturbation method. The harmonic balance method is used to find the amplitudes of the oscillatory states of the system under control. The effects of the constraint parameter and the control parameter of the model on the amplitude of oscillations are presented. The effects of the active control on the behaviors of the model are analyzed and it appears that with the appropriate selection of the coupling parameter, the chaotic behavior of the model has given way to periodic movements. Numerical simulations are used to validate and complete the analytical results obtained.

关键词： Forced Modified Van der Pol-Duffing Oscillator Chemical Dynamics Active Control and Bifurcations

Asymptotic Analysis in a Gas-Solid Combustion Model with Pattern Formation

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Chinese Annals of mathematics,Series B 2013年第1期34卷 65-88页

作者： Claude-Michel BRAUNER Lina HU Luca LORENZI School of mathematical sciences Xiamen University institut de mathématiques de Bordeaux Université de Bordeaux Dipartimento di Matematica e Informatica Università degli Studi di ParmaParco Area delle Scienze 53/A

The authors consider a free interface problem which stems from a gas-solid model in combustion with pattern formation. A third-order, fully nonlinear, self-consistent equation for the flame front is derived. Asymptotic methods reveal that the interface approaches a solution to the Kuramoto-Sivashinsky equation. Numerical results which illustrate the dynamics are presented.

关键词： Asymptotics Free interface Kuramoto-Sivashinsky equation Pseudo-differential operator Spectral method