In this paper, some counterexamples are offered to illustrate that some results stated in a recent paper on the oscillatory behavior of solutions of second order nonlinear difference equation are incorrect.
By means of an abstract continuation theory for k-set contraction and continuation theorem of coincidence degree principle, some criteria are established for the existence of positive periodic solutions of following neutral functional differential equation
In this paper, the problenl of absohlte stability for general Lurie control systems with multi- nonlinear feedback terms is investigated. From the Lyapunov function approach. new necessary and sufficient conditious and some practical sufficient conditions of absolute stability are derived. which improve the absolute stability for the set. A numerical examplc illustrates the effectiveness of the proposed results.
The existence of infinitely many solutions to Sturm-Liouville boundary value problem with a Laplacian-like operator is studied by applying generalized polar coordinates.
Wei-ping Sun, Wei-gao GeDepartment of Applied Mathematics, Beijing Institute of Technology, Beijing 100081, China
