Introduction

Abstract

It is no exaggeration to say that we are living in a world of contact. Babies learn many things by touching, rubbing and grasping and a lot of times it has been said that one cannot live alone. If someone is isolated from the world, he will feel lonely and will also question his own existence as his emotions and feelings are affected by other people. It is also true that various sorts of friction may appear among people as each person has his own way of contact. Different ways of contact sometimes cause different kinds of friction. Contact and friction are closely related in the human world. These phenomena can also be observed in the physical world and since they are highly nonlinear, it is difficult to find good solutions easily. People are involved in contact problems whether they are small or large and we have to make every effort to solve them.