Notice of RetractionPositive solutions for nonlinear four-order m-point boundary value problems with sign changing nonlinearities

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE\´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

In this paper, we investigate the existence of positive solitions for nonlinear four-order m-point boundary value problem {u⁽⁴⁾(t) = λh(t)f(t,u), 0<;t<;1, β₁u(0) - γ₁u\´(0) = 0, u(1) = Σ_i=1^m-2 a_iu(ξ_i), β₂u"(0)-γ₂u\´"(0)=0 u"(1)=Σ_i=1^m-2 b_iu"(ξ_i), where the nonlinear term f is allowed to change sign.