4 papers
math.FA2019
New coincidence point and fixed point theorems for essential distances and -metrics
Wei-Shih Du
In this paper, we establish some new fixed point theorems and coincidence point theorems for essential distances and -metrics which generalize and improve Berinde-Berinde's…
math.FA2015
On characterizations of -functions
Wei-Shih Du
In this paper, we introduce and share the new concept of -functions and its some characterizations.
math.FA2015
The Hyers-Ulam stability for nonlinear Volterra integral equations via a generalized Diaz-Margolis's fixed point theorem
Wei-Shih Du
In this work, we prove an existence theorem of the Hyers-Ulam stability for the nonlinear Volterra integral equations which improves and generalizes Castro-Ramos theorem by using s…
math.FA2010
A short note on the paper "Remarks on Caristi's fixed point theorem and Kirk's problem"
Wei-Shih Du
In this paper, we demonstrate that Li's fixed point theorems are indeed equivalent with the primitive Caristi's fixed point theorem, Jachymski's fixed point theorems, Feng and Liu'…