En | Ar
Photo Enseignant

Toni SAYAH

Faculté des sciences (FS)
Unité de recherche : mathématiques et modélisation (UR-MM)

professeur -

(+961) 1 421 000 ext 3373 toni.sayah@usj.edu.lb

1- Formations et titres universitaires

* Habilitation à diriger des recherches en mathématiques, du laboratoire Jacques
Louis-Lions (LJLL) de l'Université Pierre et Marie Curie, Paris VI.

*  Thèse de doctorat en mathématiques appliquées, mention très honorable, du
laboratoire d'analyse numérique de l'Université Pierre et Marie Curie, Paris VI.

*  DEA analyse numérique de l'École Polytechnique (Palaiseau 1994).

*  Diplôme d'ingénieur, Université Libanaise, (Liban 1993).

1- Parcours professionnel

*  Depuis septembre 2013 : professeur au département de mathématiques de la faculté des sciences de l'Université Saint-Joseph de Beyrouth.

 * 2000 - 2008 : maître de conférence à la faculté des sciences de l'Université Saint-Joseph de Beyrouth.

 * 1995 - 2000 : chercheur à la société IMACS, Ecole Polytechnique, 91128 Palaiseau Cedex, France.

*  Diplôme d'ingénieur, Université Libanaise, (Liban 1993).

3- Responsabilités administratives à la faculté des sciences de l'Université Saint-Joseph.

*  Depuis septembre 2014 à la FS-USJ : Directeur de l'unité de recherche "UR-MM : Mathématiques et modélisation".

 * 2012 - 2014 à la FS-USJ :  Responsable du master "Sciences actuarielle et financière".

 * 2006 - 2012 : directeur du département de mathématiques.

* 2005 - 2006 : responsable des masters "Sciences actuarielle et financière" et "Analyse numérique : option équations aux dérivées partielles".

* 2002 - 2005 : responsable du master "Mathématiques et informatique pour la nance".


Domaine d’expertise

• Ingénierie et technologie; Sciences

Thématiques de recherche

Discrétisation des équations aux dérivées partielles et analyse numérique correspondante, avec applications en :

1. Ondes électromagnétiques :
 -Méthodes des équations intégrales pour l'étude des problèmes de diffraction des
ondes électromagnétiques par différents types d'obstacles (obstacle conducteur
parfait, obstacle avec conditions d'impédances, obstacle diélectrique, . . .)
 -Propagation des ondes électromagnétiques dans des guides d'ondes et étude des
jonctions.

2. Mécanique des fluides :
 -Etudes des estimations d'erreur a priori et a posteriori pour différents types de
problèmes de fluide (Stokes, Navier-Stokes, Fluide de grade deux, Problème de
type convection diffusion réaction. . .) stationnaires et instationnaires.
 -Méthode de deux grilles pour les équations de Navier-Stokes.


1- Rim Aldbaissy, Frédéric HECHT, Gihane Mansour, Toni SAYAH and Pierre Henri Tournier, Scalable domain decomposition preconditioner for Navier-Stokes equations coupled with the heat equation, International Journal of Computer Mathematics, https ://doi.org/10.1080/00207160.2021.1925888, (2021).

2- Nancy Chalhoub, Pascal Omnes, Toni Sayah and Rebecca El Zahlaniyeh, A Posteriori error estimates for the time dependent convection-diusion-reaction equation coupled with the Darcy system, "Numerical Algorithms", https ://doi.org/10.1007/s11075-021-01152-3, (2020).

3- Toufic El Arwadi and Toni Sayah, A new regularization of the D-bar Method with complex conductivity, to Complex Variables and Elliptic Equations, 66(5), pp. 826-842, DOI : 10.1080/17476933.2020.1747056, (2021).

4- Jad Dacroub, Joanna Faddoul and Toni Sayah, A posteriori analysis of the Newton method applied to the Navier-Stokes problem, Journal of applied mathematics and computing, 63, pp. 411-437, DOI : 10.1007/s12190-020-01323-w, (2020).

5- Dayana Dib, Séréna Dib and Toni Sayah, A new numerical scheme for Darcy's problem coupled with the heat equation, Computational and applied mathematics, 39 (1), pp :1-16, DOI : 10.1080/17476933.2020.1747056, (2020).

6- Nancy Chalhoub, Pascal Omnes, Toni Sayah and Rebecca Zahlaniyeh, Full discretization of time dependent convection-diffusion-reaction equation coupled with the Darcy system, CALCOLO, 57(4), pp. 3-28, DOI : 10.1007/s10092-019-0352-1, (2020).

7- Séréna Dib, Vivette Girault, Frédéric Hecht and Toni Sayah, A posteriori error
estimate for Darcy's problem coupled with the heat equation, ESIAM : Mathematical Modelling and Numerical Analysis, 53 (6), pp. 2121-2159, (2019).

8- Toufic El Arwadi and Toni Sayah, A Regularization Scheme for 2D Conductivity Imaging by the D-bar Method, Numerical Functional Analysis and Optimization, 40 (12), pp. 1410-1425, DOI :10.1080/01630563.2019.1606011, (2019).

9- Toni Sayah, Adaptive stratified Monte Carlo algorithm for numerical computation of integrals, Mathematics and Computers in Simulation, 157, pp. 143-158, doi.org/10.1016/j.matcom.2018.10.004, (2019).

10- Noura Morcos and Toni Sayah, reduced basis method for the adapted mesh and Monte Carlo methods applied to an elliptic stochastic problem, Computational and Applied Mathematics, 38(93), DOI : 10.1007/s40314-019-0859-8, (2019).

11- Mireille Haddad, Frédéric Hecht, Toni Sayah and Pierre Henri Tournier, Parallel computing investigations for the projection method applied to the interface transport scheme of a two-phase ow by the method of characteristics, Numerical Algorithm, 80(2), pp. 447-467, https ://doi.org/10.1007/s11075-018-0492-4, (2018).

12- Rim Dbaissy, Frédéric Hecht, Gihane Mansour and Toni Sayah, A full discretization of the time-dependent Boussinesq (buoyancy) model with nonlinear viscosity, CLACOLO, 55(44), DOI :10.1007/s10092-018-0285-0 (2018).

13- Séréna Dib, Toni Sayah, Vivette Girault, François Murat, Christine Bernardi and Frédéric Hecht, Finite element method for Darcy's problem coupled with the heat equation, Numerische Mathematik, 139(2), pp. 315-348, DOI10.1007/s00211-017-
0938-y, (2018).

14- Ghina Nassreddine, Toni Sayah, New Results for the A Posteriori Estimates of the Two Dimensional Time Dependent Navier-Stokes Equation, International Journal of Mechanics, 11, pp. 155-165, (2017).

15- Christine Bernardi, Jad Dakroub, Gihane Mansour, Farah Rafei and Toni Sayah, Convergence analysis of two numerical schemes applied to a nonlinear elliptic problem, Journal of Scientic Computing, 71 (1), DOI : 10.1007/s10915-016-0301-y, (2017).

16- Mireille El Haddad, Frédéric Hecht and Toni Sayah, Interface transport scheme of a two-phase ow by the method of characteristics, International Journal for Numerical Methods in Fluids, DOI :10.1002/d.4280, 28, 6, (2017), pp 513-543.

17- Christine Bernardi, Jad Dakroub, Gihane Mansour and Toni Sayah, A posteriori analysis of iterative algoriths for Navier-Stokes Problem, ESIAM : Mathematical Modelling and Numerical Analysis, 50 (4), doi :10.1051/m2an/2015062, (2016), pp. 1035-1055.

18- Toufic El Arwadi and Toni Sayah, An Lp estimate for Dirichlet-to-Neumann operator and application., Electronic Journal of Dierential Equations, Vol. 2015, No.258, pp. 1-8, (2015).

19- Toufic El Arwadi, Serena Dib and Toni Sayah, A piori and a posteriori estimations of a linear elliptic problem with dynamical boudary condition, 9, 6, doi :10.12785/amis/100121, Journal of Applied Mathematics & Information Sciences, (2015), pp 2205-3317.

20- Christine Bernardi and Toni Sayah, A posteriori error analysis of the time dependent Navier-Stokes equations with mixed boundary conditions, 69, 1, DOI 10.1007/s40324-015-0033-1, SeMA Journal (SEMJ), (2015), pp 1-23.

21- Christine Bernardi, Jad Dakroub, Gihane Mansour and Toni Sayah, A posteriori analysis of iterative algorithms for a nonlineair problem, Journal of Scientic Computing, 65, 2, DOI 10.1007/s10915-014-9980-4, (2015), pp 672-697.2

22-  Christine Bernardi and Toni Sayah, A posteriori error analysis of the time dependent Stokes equations with mixed boundary conditions, IMA J Numer Anal, 35, 1, 2015, doi : 10.1093/imanum/drt067(2012), pp 179-198.

23- Fida El Chami, Gihane Mansour et Toni Sayah, Error studies of the Coupling
Darcy-Stokes systems with velocity-pressure formulation, CALCOLO, 49, Issue 2 (2012), Page 73-93.

24- Hyam Abboud, Fida El Chami et Toni Sayah, A priori and a posteriori estimates for three-dimensional Stokes equations with non standard of boundary conditions, Numerical Methods for Partial Differential Equations, Volume 28, (2012), pp 1178-1193.

25- Hyam Abboud, Fida El Chami et Toni Sayah, Error estimates for three-dimensional Stokes problem with non-standard boundary conditions, C. R. Acad. Sci. Paris, Ser. I 349, (2011), pp. 523-528.

26- Touc Abboud et Toni Sayah, Retarded Potential Method for Computational Electromagnetics,
Proceedings of AP2000 Millennium Conference on Antennas & Propagation,
Davos-Switzerland, April 9-14, 2000. ESA Publication, CD-ROM SP-444.

27- Fida El Chami et Toni Sayah, A posteriori error estimators for the fully discrete time dependent Stokes problem with some different boundary conditions , CALCOLO, 47 (2010), pp 169-192.

28- Hyam Abboud, Vivette Girault et Toni Sayah, A second order accuracy in time for a full discretized time-dependent Navier-Stokes equations by a two-grid scheme, Numerische Mathematik, 14, 2 (2009) pp. 189-231.

29- Hyam Abboud et Toni Sayah, Upwind discretisation of a time-dependent two dimensional grade-two uid model, Computers & Mathematics with applications, 57 (2009), pp. 1249-1264.

30- Hyam Abboud et Toni Sayah, A full discretization of the time-dependent Navier-Stokes by two-grid scheme, ESIAM : Mathematical Modelling and Numerical Analysis, vol. 42, No. 1 (2008), pp 141-174.

31- Hyam Abboud, Vivette Girault et Toni Sayah, Two-grid scheme for the fully discrete time-dependent Navier-Stokes problem, C. R. Acad. Sci. Paris , ser.I 341
(2005), pp 451-456.

32- Toni Sayah et Badih Azar, Eect of Junction on Electromagnetic Waveguide transmission, Mathematica Balkanica, vol. 18, No 3-4 (2004), pp 443-452.

33- Toni Sayah et Badih Azar, Coupling finite element method-modal expansion method for the junction of electromagnetic waveguides, International journal of applied mathematics, vol. 12, No 3 (2003), pp 221-234.

34- Toufic Abboud et Toni Sayah, Discretisation of the Engquist-Nedelec approximation of thin layer, International journal of computational and numerical analysis and applications, vol. 3, No 3, (2003), pp 249-261.

35-Toni Sayah, Boundary conditions for the electromagnetic scattering by thin layers, International journal of applied mathematics, vol. 11, No 2 (2002), pp 121-136.

36- Toufic Abboud et Toni Sayah, Retarded Potential Method for Computational Electromagnetics, Proceedings of AP2000 Millennium Conference on Antennas & Propagation, Davos-Switzerland, April 9-14, 2000. ESA Publication, CD-ROM SP-444.

37- Touic Abboud et Toni Sayah, The retarded potential method for computational electromagnetics, Proceedings of the 3rd European Conference on Numerical Mathematics and Advanced Applications, Jyvskyl, Finland, July 26-30, 1999, ed. by P. Neittaanmki, T. Tiihonen and P. Tarvainen, World Scientic, Singapore, 2000, pp. 198-205.

38- Toufic Abboud, Joseph El Gharib, Jean Claude Nédélec et Toni Sayah, An accelerated retarded potential method for the time dependent wave scattering , ASME 15th Biennal Conference on Mechanical Vibration and Noise, Boston, septembre 1995, pp. 3-8.