Minimal networks for sensor counting problem using discrete Euler   calculus
  This paper proposes a method to reduce noise in acyclic sensor networks enumerating targets using the integral theory with respect to Euler characteristic. For an acyclic network (a partially ordered set) equipped with sensors detecting targets, we find reducible points for enumerating targets, as a generalization of weak beat points (homotopically reducible points). This theory is useful for improving the reliability and optimization of acyclic sensor networks. 
Kohei Tanaka
math.CO