P systems with symport/antiport rules of a minimal size (only one object passes in any direction in a communication step) were recently proven to be computationally universal. The proof from [2] uses systems with nine membranes. In this paper we improve this results, by showing that six membranes suffice. The optimality of this result remains open (we believe that the number of membranes can be...

What motivates firms to develop Internet-enabled interfirm communication? We draw upon the work of Alavi et al. (2005–2006) and propose that the use of the Internet in interfirm communication is influenced by a firm’s firm orientation and its internal communities of practice. Based on data collected from 307 international trade firms in the Beijing area, we find that Internet-enabled interfirm ...

The smooth interpolation of keyframes of a rigid body, in particular their orientations, is an important problem in animation . Using the quaternion as a representation for orientation, several papers have solved this problem through the generation of smooth curves on the quaternion sphere. However, none of these methods have constructed rational curves. This paper develops a method for generat...