D. Shafer

发表

Leonid Antonovich Cherkas

V. I. Mironenko, I. Gaishun, N. Vulpe, 2011 .

Cyclicity of polynomial nondegenerate centers on center manifolds

I. A. García, D. Shafer, Susanna Maza, 2018, Journal of Differential Equations.

Cyclicity of a class of polynomial nilpotent center singularities

I. A. García, D. Shafer, 2015 .

Asymptotics and stability of the delayed Duffing equation

D. Shafer, David R. C. Hill, 2018, Journal of Differential Equations.

Gradient vectorfields near degenerate singularities

Douglas S. Shafer, D. Shafer, 1980 .

Structure and Stability of Gradient Polynomial Vector Fields

D. Shafer, 1990 .

Integral invariants and limit sets of planar vector fields

I. A. García, D. Shafer, 2005 .

Structural Stability of Planar Polynomial Foliations

J. Llibre, D. Shafer, X. Jarque, 2005 .

Weak Singularities of Planar Vector Fields Under Weak Perturbation

D. Shafer, 2004 .

Multiple bifurcation in a predator–prey system with nonmonotonic predator response

F. Rothe, Douglas S. Shafer, D. Shafer, 1992, Proceedings of the Royal Society of Edinburgh: Section A Mathematics.

Bifurcation in a quartic polynomial system arising in biology

F. Rothe, Douglas S. Shafer, D. Shafer, 1990 .

Topological conjugacy of singularities of vector fields

D. Shafer, R. B. Walker, Richard Swanson, 1986 .

Singularities of gradient vectorfields in R3

D. Shafer, 1983 .

Separatrix and limit cycles of quadratic systems and Dulac’s theorem

Carmen Chicone, C. Chicone, Douglas S. Shafer, 1983 .

Quadratic Morse-Smale vector fields which are not structurally stable

C. Chicone, D. Shafer, 1982 .

Topological equivalence of gradient vectorfields

D. Shafer, 1980 .

Bifurcation of critical periods of polynomial systems

V. Romanovski, D. Shafer, V. Levandovskyy, 2015 .

The Center and Cyclicity Problems: A Computational Algebra Approach

Valery G. Romanovski, V. Romanovski, Douglas S. Shafer, 2009 .

Vertices of planar curves under the action of linear transformations

D. Shafer, A. Zegeling, 2002 .

SEPARATRIX AND LIMIT CYCLES OF

C. Chicone, D. Shafer, Quadratic Systems, 2016 .

The center problem on a center manifold in R^3

Valery G. Romanovski, Victor F. Edneral, V. Romanovski, 2012 .

Geometry of cycles in quadratic systems

D. Shafer, A. Zegeling, 2002 .

Properties of Monodromic Points on Center Manifolds in $${\mathbb {R}}^3$$R3 via Lie Symmetries

I. A. García, D. Shafer, Susanna Maza, 2013 .

Properties of Monodromic Points on Center Manifolds in R 3 via Lie Symmetries

I. A. García, D. Shafer, Susanna Maza, 2013 .

Center cyclicity of Lorenz, Chen and Lü systems

I. A. García, D. Shafer, Susanna Maza, 2019, Nonlinear Analysis.

Separatrix and limit cycles of quadratic systems and Dulac’s theorem

C. Chicone, D. Shafer, 1983 .

Symbolic computation and the cyclicity problem for singularities

Douglas S. Shafer, D. Shafer, 2012, J. Symb. Comput..

The cyclicity of a cubic system with nonradical Bautin ideal

V. Romanovski, D. Shafer, V. Levandovskyy, 2009 .

The 1: -q resonant center problem for certain cubic Lotka-Volterra systems

Xingwu Chen, V. Romanovski, J. Giné, 2012, Appl. Math. Comput..

On the Center Problem for $p:-q$ Resonant Polynomial Vector Fields

Valery G. Romanovski, V. Romanovski, Douglas S. Shafer, 2008 .

1: -3 resonant centers on C2 with homogeneous cubic nonlinearities

Valery G. Romanovski, Douglas S. Shafer, Zhaoping Hu, 2008, Comput. Math. Appl..

STABILITY AND PERIODIC OSCILLATIONS IN THE MOON-RAND SYSTEMS

Valery G. Romanovski, V. Romanovski, Adam Mahdi, 2013 .

Symbolic Iterative Solution of Volterra Integral Equations

D. Shafer, Hamid Semiyari, 2016, 1611.04062.

Symbolic Iterative Solution of Two-Point Boundary Value Problems

D. Shafer, Hamid Semiyari, 2016, 1610.07232.

BIFURCATION OF LIMIT CYCLES FROM QUADRATIC CENTERS

D. Shafer, A. Zegeling, D. S. Shafer, 1995 .