On the existence of singular solutions.
On the exponential stability of a certain Lurie system
On the Floquet theory of differential equations with a complex coefficient of the real variable
On the focal points of solutions of a certain fourth order differential equation
On the generalized Floquet theory of disconjugate differential equations
On the global dynamics of the cancer AIDS-related mathematical model
In this paper we examine some features of the global dynamics of the four-dimensional system created by Lou, Ruggeri and Ma in 2007 which describes the behavior of the AIDS-related cancer dynamic model in vivo. We give upper and lower ultimate bounds for concentrations of cell populations and the free HIV-1 involved in this model. We show for this dynamics that there is a positively invariant polytope and we find a few surfaces containing omega-limit sets for positive half trajectories in the positive...
On the integrability of quasihomogeneous systems and quasidegenerate infinity systems.
On the intersection of groups of dispersions of the equation and of its accompanying equation
On the intersection of groups of increasing dispersions in two second order oscillatory differential equations
On the intersection of the set of solutions of two Kummer's differential equations
On the isospectral beams.
On the -boundedness of solutions for products of quasi-integro differential equations.
On the -solutions to general second-order nonsymmetric differential equations.
On the limit cycle of the Liénard equation
In the paper, we give an existence theorem of periodic solution for Liénard equation , . As a result, we estimate the amplitude (maximal -value) of the limit cycle of the van der Pol equation , from above by for every . The result is an improvement of the author’s previous estimation .
On the limit cycle of the van der Pol equation
On the Limit Point Classification of Second Order Differential Equations.
On the Limit-Point and Strong Limit-Point Classification of 2 n-th Order Differential Expressions with Widly Oscillating Coefficients.
On the linearization of second-order differential and difference equations.
On the Liouville-type transformation for differential systems
On the Location of Zeros of Solutions of f'' + A(z)f = 0 where A(z) is Entire.