Model Conceptualization is the most important activity in the development of a system dynamics model. Since Randers’ classic paper 23 years ago, researchers in the field have worked in the development and refinement of tools and methods to improve the process. Although progress has been made, we still lack understanding of the process itself. The purpose of the paper is to review the progress i...

In this paper we study the two-dimensional complex Finsler spaces with (α, β)-metrics by using the complex Berwald frame. A special approach is dedicated to the complex Berwald spaces with (α, β) metrics. We establish the necessary and sufficient condition so that the complex Randers and Kropina spaces should be complex Berwald spaces, and we will illustrate the existence of these spaces in som...

Abstract Given a complete non-compact Riemannian manifold ( M , g ) with certain curvature restrictions, we introduce an expansion condition concerning group of isometries G that characterizes the coerciveness in sense Skrzypczak and Tintarev (Arch Math 101(3): 259–268, 2013). Furthermore, under these conditions, compact Sobolev-type embeddings à la Berestycki-Lions are proved for full range ad...