This paper explores proofs of the isoperimetric inequality for 4-connected shapes on the integer grid Z, and its geometric meaning. Pictorially, we discuss ways to place a maximal number unit square tiles on a chess board so that the shape they form has a minimal number of unit square neighbors. Previous works have shown that “digital spheres” have a minimum of neighbors for their area. We here...

Abstract. The perimeter functional is known to oppose serious difficulties when it has to be handled within a topology optimization procedure. In this paper, a regularized perimeter functional Perε, defined for 2d and 3d domains, is introduced. On one hand, the convergence of Perε to the exact perimeter when ε tends to zero is proved. On the other hand, the topological differentiability of Perε...

We study the inflated phase of two dimensional lattice polygons, both convex and column-convex, with fixed area A and variable perimeter, when a weight μ exp[−Jb] is associated to a polygon with perimeter t and b bends. The mean perimeter is calculated as a function of the fugacity μ and the bending rigidity J . In the limit μ → 0, the mean perimeter has the asymptotic behaviour 〈t〉/4 √ A ≃ 1−K...

Introduction: Mechanical stimulation of human mesenchymal stem cells has demonstrated changes in many cell behaviours such as adhesion, migration, growth and differentiation through mechanotransductive pathways. These include experiments on effect of nanotopography 1, shear stress, stiffness of extracellular matrix 2, strain, stress and acoustic wave energy 3 on cells. In this research we wer...

An explicit expression is obtained for the perimeter and area generating function G(y, z) = ∑ n>=2 ∑ m>=1 cn,my z, where cn,m is the number of row-convex polygons with area m and perimeter n. A similar expression is obtained for the area-perimeter generating function for staircase polygons. Both expressions contain q-series.