Professor of Mathematics

The University of Texas at San Antonio

Office: 210-458-4758

E-Mail: sahmad@utsa.edu

E-Mail: sahmad@utsa.edu

B.S. (Math), University of Utah, June, 1960

M.S. (Math), University of Utah, June, 1962

Ph.D. (Math), Case Western Reserve University, January, 1968.

M.S. (Math), University of Utah, June, 1962

Ph.D. (Math), Case Western Reserve University, January, 1968.

Professor, Mathematics |
University of Texas at San Antonio | 1995 – Present |

Head, Mathematics and Statistics Department |
Mississippi State University | January – May, 1999 |

Director, Mathematics Computer Science, Statistics |
University of Texas at San Antonio | 1989 – 1995 |

Chair, Department of Mathematics and Computer Sciences |
University of Miami | 1987 – 1989 |

Dean of Arts and Sciences |
University of West Florida | 1986 – 1987 |

Chair, Department of Mathematics and Computer Science |
University of Miami | 1980 – 1986 |

Chair, Department of Mathematics |
Oklahoma State University | 1978 – 1980 |

Professor, Department of Mathematics |
Oklahoma State University | 1975 – 1978 |

Associate Professor |
Oklahoma State University | 1970 – 1975 |

Assistant Professor |
Oklahoma State University | 1968 – 1970 |

Instructor |
Case Western Reserve University | 1966 – 1968 |

Assistant Professor |
University of North Dakota | 1965 – 1966 |

Instructor |
South Dakota State University | 1962 – 1964 |

S. Ahmad, A.C. Lazer, and A. Tineo, Traveling waves for a system, to appear In *Nonlinear Analysis.*

S. Ahmad, A. Tineo, Three-dimensional population systems, to appear in*Non-linear Analysis -RWA.*

S. Ahmad and I. Stamova, Asymptotic stability of an N-dimensional impulsive competitive systems,*Nonlinear Analysis- RWA 8 (2007). *

S. Ahmad and I. Stamova, Survival and extinction in competitive systems, to appear in*Nonlinear Analysis-RWA.*

S. Ahmad and A.C. Lazer, Average growth and total permanence,*Annali di Matematica Pura ed Applicata 185, S47-S67 (2006).*

S. Ahmad and I. Stamova, Partial persistence and survival in N-dimensional competitive systems,*Nonlinear Analysis- 60 (2005).*

S. Ahmad and A.C. Lazer, Average growth and extinction in a competitive Lotka-Volterra System,*Nonlinear Analysis 62 (2005).*

S. Ahmad and I. Stamova, Almost necessary and sufficient conditions for survival of Species,*Nonlinear Analysis-Real World Applications 5 ( 2004).*

S. Ahmad and A.C. Lazer, On persistence and extinction of species, Summer School on Mathematical Biology,*Centro Internacionale de Matematica 20, Portugal (2002). *

S. Ahmad and F.M. de Oca, Average growth and extinction in a two dimensional Lotka-Volterra system,*Dynamics of Continuous, Discrete, and Impulsive Systems 9 No.2 (2002). *

S. Ahmad and A.C. Lazer, Average conditions for global asymptotic stability in a nonautonomous Lotka-Volterra system,* Nonlinear Analysis 40 (2000).*

S. Ahmad, Extinction of species in nonautonomous Lotka-Volterra systems,*Proc. Amer. Math. Soc 127 No.10 (1999).*

S. Ahmad and M. R. M. Rao, Ordinary Differential Equations (book),*Affiliated East-West Press PVT, Ltd., India (1999).*

S. Ahmad and A.C. Lazer, On a property of nonautonomous Lotka-Volterra competition model,*Nonlinear Analysis 37 (1999).*

__________. Necessary and sufficient average growth in a Lotka-Volterra system,*Nonlinear Analysis 34 (1998).*

S. Ahmad and F. M. de Oca, Extinction in nonantonomous T-periodic competitive Lotka-Volterra systems,*Applied Mathematics and Computation 90 (1998).*

S. Ahmad and M.R.M. Rao, Stability of Volterra diffusion equations with time delay to appear in*Applied Mathematics and Computations 90 (1998).*

S. Ahmad and A. Tineo, Almost periodic solutions of second order systems*Applicable Analysis 63 (1996).*

S. Ahmad and A.C. Lazer, One species extinction in an autonomous competition model,*Proceedings of The First World Congress on Nonlinear Analysis*, Walter de Gruyter, Berlin, 1996.

Proceedings of Dynamic Systems and Applications, Vol. 2,*Dynamic Publishers Inc*., 1996 (member of editorial committee).

S. Ahmad and A. C. Lazer, On the nonautonomous N-competing species problem,* Applicable Analysis 57 (1995).*

S. Ahmad and M. R. M. Rao, Asymptotically periodic solutions of N-competing species problem with time delay,*J. of Math. Anal. and Appl., 186 No. 2 (1994).*

__________, Stability criteria for N-competing species problem with time delays,*Nonlinear World 1 (1994).*

S. Ahmad, On the nonautonomous Volterra - Lotka competition equations,*Proc. of the AMS 117, No. 1 (1993).*

__________, A nonstandard resonance problem for ODE,*Trans. of the AMS 323, No. 2 (1991).*

S. Ahmad and A. C. Lazer, An elementary approach to traveling front solutions to a system of N competition - diffusion equations,*J. of Nonlinear Analysis 16 No. 10 (1991).*

__________, The No Retraction Theorem and comparison of focal points of second-order nonselfadjoint systems,*Revista de Matematicas Aplicadas No. 11 (1990).*

__________, Asymptotic behavior of solutions of periodic competition diffusion systems,* J. of Nonlinear Analysis 13, No. 3 (1989).*

S. Ahmad, On almost periodic solutions of the competing species problems,*Proc. of the AMS, 102 No. 4 (1988).*

__________, Convergence and ultimate bounds of solutions of nonautonomous Volterra-Lotka competition equations,* J. of Math. Anal. and Appl., 127, No. 2 (1987).*

__________, Multiple nontrivial solutions of resonant and nonresonant asymptotically linear problems,* Proc. of the AMS 96, No. 3 (1986).*

__________, Nonselfadjoint resonance problems with unbounded perturbations,*J. of Nonlinear Analysis 10, No. 2 (1986)*. (Also published as a technical report, Sonderforschungsbereich 72, University of Bonn).

__________, A resonance problem in which nonlinearity may grow linearly,* Proc. of the AMS 92, No. 3 (1984).*

S. Ahmad and A. C. Lazer, Critical point theory and a theorem of Amaral and Pera,*Boll. U. M. I. 6 3-B (1984).*

S. Ahmad and F. M. de Oca, Nonconstant periodic solutions of second order autonomous systems,*Proceedings of the Vth International Conference on Trends in Theory and Practice on Nonlinear Differential Equations*, Marcel Dekker, Inc. (1983).

__________, On existence of nonconstant periodic solutions I,* J. of Nonlinear Analysis 7, No. 11 (1983).*

S. Ahmad, On existence of nonconstant periodic solutions II,* J. of Nonlinear Analysis 7, No. 11 (1983).*

__________, On Sturmian theory for second order systems,* Proc. of the AMS 87, No. 4 (1983).*

S. Ahmad and A. C. Lazer, On an extension of Sturm’s Comparison Theorem, SIAM*J. of Math. Anal. 12, No. 1 (1981).*

S. Ahmad and A. S. Vatsala, Comparison results or reaction-diffusion equations with delay in abstract cones,*Rend. Sem. Math. Univ. Padova 65 (1981).*

S. Ahmad and J. Salazar, Conjugate points and second order systems,*J. of Math. Anal. and Appl. 84, No. 1 (1981).*

__________, On existence of periodic solutions of nonlinearly perturbed conservative systems, Proc. of the Eighth Fall Conference on Differential Equations, Academic Press (1980).

S. Ahmad and A. C. Lazer, On nth order Sturmian theory,* J. of Differential Equations 35, No. 1 (1980).*

S. Ahmad, M. S. Keener and A. C. Lazer, eds., Proc. of the Eighth Fall Conference on Differential Equations,*Academic Press (1980).*

S. Ahmad and A. C. Lazer, On the role of Hopf’s Maximum Principle in elliptic Sturmian theory, Houston* J. of Math. 5, No. 2 (1979).*

S. Ahmad, On positivity of solutions and conjugate points of nonselfadjoint systems,*Bull. de l’Academie Polonaise des Sciences, XXVII, No. 1 (1970).*

S. Ahmad and A. C. Lazer, A new generalization of the Sturm comparison theorem to selfadjoint systems,*Proc. of the AMS 68, No. 2 (1978).*

S. Ahmad and C. Travis, Oscillation criteria for second-order differential systems,*Proc. of the AMS 71, No. 2 (1978).*

S. Ahmad and J. Sarabia, On nonwandering continuous flows,*Funck. Ekvac. 21, No. 3 (1978).*

S. Ahmad and A. C. Lazer, An N-dimensional extension of the Sturm Separation and Comparison theorems to a class of nonselfadjoint systems, SIAM* J. of Math. Anal. 9, No. 6 (1978).*

__________, Positive operators and Sturmian theory of nonselfadjoint second-order systems,*Nonlinear Equations in Abstract Spaces, Academic Press (1978).*

__________, On the components of extremal solutions of second-order systems, SIAM* J. of Math. Anal., 8, No. 1 (1977).*

S. Ahmad, Asymptotic properties of linear fourth order differential equations,* Proc. of the AMS 59, No. 1 (1976).*

S. Ahmad, A. C. Lazer and J. L. Paul, Elementary critical point theory and perturbations of elliptic boundary value problems at resonance, Indiana Univ. Math.* J. 25, No. 10 (1976).*

S. Ahmad and A. C. Lazer, Component properties of second order linear systems,*Bull. of the AMS, 82, No. 2 (1976).*

S. Ahmad and Abdelali Benharbit, Some oscillation properties of third order linear homogeneous differential equations,*Annal. Polon. Math. 31 (1975).*

S. Ahmad, Oscillation properties of third order linear differential equations and their adjoints,*J. of Math. and Phys. Sci. 8, No. 3 (1974).*

__________, Periodically perturbed conservative systems,* Bull. of the AMS 80, No. 1 (1974).*

__________, An existence theorem for periodically perturbed conservative systems, Mich. Math.* J., 20 (1973).*

__________, Strong attraction and classification of certain continuous flows,* Lecture Notes in Math., Springer-Verlang 5, No. 2 (1971).*

__________, Flows of Characteristic O+,*Math. Systems Th. 5, No. 1 (197*

__________, Dynamical systems of characteristic O+, Pac. Math.*J. 32, No. 3 (1970).*

__________, On the oscillation of solutions of a class of linear fourth order differential equations, Pac. Math.*J. 34, No. 2 (1970).*

__________, Split dilations of finite groups with applications to finite fields, Duke Math*. J., 38, No. 3 (1970).*

__________, On Ura’s axioms and local dynamical systems,*Funck. Ekvac. 12, No. 2 (1969).*

S. Ahmad and A. C. Lazer, On the oscillatory behavior of a class of linear third order differential equations,*J. of Math. Anal. and Appl. 28, No. 3 (1969).*

S. Ahmad, Cycle structure of finite cyclic groups,*Combinatorial Theory 6, No. 4 (1969).*

__________, Absolute independency axioms for the derived set operator,*Amer. Math. Monthly 73, No. 4 (1966).*

__________, The Kuratowski closure axioms,* Math. Magazine 37, No. 5 (1964).*

S. Ahmad, A. Tineo, Three-dimensional population systems, to appear in

S. Ahmad and I. Stamova, Asymptotic stability of an N-dimensional impulsive competitive systems,

S. Ahmad and I. Stamova, Survival and extinction in competitive systems, to appear in

S. Ahmad and A.C. Lazer, Average growth and total permanence,

S. Ahmad and I. Stamova, Partial persistence and survival in N-dimensional competitive systems,

S. Ahmad and A.C. Lazer, Average growth and extinction in a competitive Lotka-Volterra System,

S. Ahmad and I. Stamova, Almost necessary and sufficient conditions for survival of Species,

S. Ahmad and A.C. Lazer, On persistence and extinction of species, Summer School on Mathematical Biology,

S. Ahmad and F.M. de Oca, Average growth and extinction in a two dimensional Lotka-Volterra system,

S. Ahmad and A.C. Lazer, Average conditions for global asymptotic stability in a nonautonomous Lotka-Volterra system,

S. Ahmad, Extinction of species in nonautonomous Lotka-Volterra systems,

S. Ahmad and M. R. M. Rao, Ordinary Differential Equations (book),

S. Ahmad and A.C. Lazer, On a property of nonautonomous Lotka-Volterra competition model,

__________. Necessary and sufficient average growth in a Lotka-Volterra system,

S. Ahmad and F. M. de Oca, Extinction in nonantonomous T-periodic competitive Lotka-Volterra systems,

S. Ahmad and M.R.M. Rao, Stability of Volterra diffusion equations with time delay to appear in

S. Ahmad and A. Tineo, Almost periodic solutions of second order systems

S. Ahmad and A.C. Lazer, One species extinction in an autonomous competition model,

Proceedings of Dynamic Systems and Applications, Vol. 2,

S. Ahmad and A. C. Lazer, On the nonautonomous N-competing species problem,

S. Ahmad and M. R. M. Rao, Asymptotically periodic solutions of N-competing species problem with time delay,

__________, Stability criteria for N-competing species problem with time delays,

S. Ahmad, On the nonautonomous Volterra - Lotka competition equations,

__________, A nonstandard resonance problem for ODE,

S. Ahmad and A. C. Lazer, An elementary approach to traveling front solutions to a system of N competition - diffusion equations,

__________, The No Retraction Theorem and comparison of focal points of second-order nonselfadjoint systems,

__________, Asymptotic behavior of solutions of periodic competition diffusion systems,

S. Ahmad, On almost periodic solutions of the competing species problems,

__________, Convergence and ultimate bounds of solutions of nonautonomous Volterra-Lotka competition equations,

__________, Multiple nontrivial solutions of resonant and nonresonant asymptotically linear problems,

__________, Nonselfadjoint resonance problems with unbounded perturbations,

__________, A resonance problem in which nonlinearity may grow linearly,

S. Ahmad and A. C. Lazer, Critical point theory and a theorem of Amaral and Pera,

S. Ahmad and F. M. de Oca, Nonconstant periodic solutions of second order autonomous systems,

__________, On existence of nonconstant periodic solutions I,

S. Ahmad, On existence of nonconstant periodic solutions II,

__________, On Sturmian theory for second order systems,

S. Ahmad and A. C. Lazer, On an extension of Sturm’s Comparison Theorem, SIAM

S. Ahmad and A. S. Vatsala, Comparison results or reaction-diffusion equations with delay in abstract cones,

S. Ahmad and J. Salazar, Conjugate points and second order systems,

__________, On existence of periodic solutions of nonlinearly perturbed conservative systems, Proc. of the Eighth Fall Conference on Differential Equations, Academic Press (1980).

S. Ahmad and A. C. Lazer, On nth order Sturmian theory,

S. Ahmad, M. S. Keener and A. C. Lazer, eds., Proc. of the Eighth Fall Conference on Differential Equations,

S. Ahmad and A. C. Lazer, On the role of Hopf’s Maximum Principle in elliptic Sturmian theory, Houston

S. Ahmad, On positivity of solutions and conjugate points of nonselfadjoint systems,

S. Ahmad and A. C. Lazer, A new generalization of the Sturm comparison theorem to selfadjoint systems,

S. Ahmad and C. Travis, Oscillation criteria for second-order differential systems,

S. Ahmad and J. Sarabia, On nonwandering continuous flows,

S. Ahmad and A. C. Lazer, An N-dimensional extension of the Sturm Separation and Comparison theorems to a class of nonselfadjoint systems, SIAM

__________, Positive operators and Sturmian theory of nonselfadjoint second-order systems,

__________, On the components of extremal solutions of second-order systems, SIAM

S. Ahmad, Asymptotic properties of linear fourth order differential equations,

S. Ahmad, A. C. Lazer and J. L. Paul, Elementary critical point theory and perturbations of elliptic boundary value problems at resonance, Indiana Univ. Math.

S. Ahmad and A. C. Lazer, Component properties of second order linear systems,

S. Ahmad and Abdelali Benharbit, Some oscillation properties of third order linear homogeneous differential equations,

S. Ahmad, Oscillation properties of third order linear differential equations and their adjoints,

__________, Periodically perturbed conservative systems,

__________, An existence theorem for periodically perturbed conservative systems, Mich. Math.

__________, Strong attraction and classification of certain continuous flows,

__________, Flows of Characteristic O+,

__________, Dynamical systems of characteristic O+, Pac. Math.

__________, On the oscillation of solutions of a class of linear fourth order differential equations, Pac. Math.

__________, Split dilations of finite groups with applications to finite fields, Duke Math

__________, On Ura’s axioms and local dynamical systems,

S. Ahmad and A. C. Lazer, On the oscillatory behavior of a class of linear third order differential equations,

S. Ahmad, Cycle structure of finite cyclic groups,

__________, Absolute independency axioms for the derived set operator,

__________, The Kuratowski closure axioms,