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Tilings of convex polygons

Richard Kenyon (1997)

Annales de l'institut Fourier

Call a polygon rational if every pair of side lengths has rational ratio. We show that a convex polygon can be tiled with rational polygons if and only if it is itself rational. Furthermore we give a necessary condition for an arbitrary polygon to be tileable with rational polygons: we associate to any polygon P a quadratic form q ( P ) , which must be positive semidefinite if P is tileable with rational polygons.The above results also hold replacing the rationality condition with the following: a polygon...

Topology of arrangements and position of singularities

Enrique Artal Bartolo (2014)

Annales de la faculté des sciences de Toulouse Mathématiques

This work contains an extended version of a course given in Arrangements in Pyrénées. School on hyperplane arrangements and related topics held at Pau (France) in June 2012. In the first part, we recall the computation of the fundamental group of the complement of a line arrangement. In the second part, we deal with characteristic varieties of line arrangements focusing on two aspects: the relationship with the position of the singular points (relative to projective curves of some prescribed degrees)...

Towards Sub-cellular Modeling with Delaunay Triangulation

G. Grise, M. Meyer-Hermann (2010)

Mathematical Modelling of Natural Phenomena

In this article a novel model framework to simulate cells and their internal structure is described. The model is agent-based and suitable to simulate single cells with a detailed internal structure as well as multi-cellular compounds. Cells are simulated as a set of many interacting particles, with neighborhood relations defined via a Delaunay triangulation. The interacting sub-particles of a cell can assume specific roles – i.e., membrane sub-particle, internal sub-particle, organelles, etc –,...

Translative packing of a square with sequences of squares

Janusz Januszewski (2010)

Colloquium Mathematicae

Let S be a square and let S' be a square of unit area with a diagonal parallel to a side of S. Any (finite or infinite) sequence of homothetic copies of S whose total area does not exceed 4/9 can be packed translatively into S'.

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