Combinatorial Calabi flows on surfaces

For triangulated surfaces, we introduce the combinatorial Calabi flow which is an analogue of smooth Calabi flow. We prove that the solution of combinatorial Calabi flow exists for all time. Moreover, the solution converges if and only if Thurston's circle packing exists. As a consequence, combinatorial Calabi flow provides a new algorithm to find circle packings with prescribed curvatures. The proofs rely on careful analysis of combinatorial Calabi energy, combinatorial Ricci potential and discrete dual-Laplacians.Comment: 17 pages, 5 figure

Anomalous minimum and scaling behavior of localization length near an isolated flat band

Using one-dimensional tight-binding lattices and an analytical expression based on the Green's matrix, we show that anomalous minimum of the localization length near an isolated flat band, previously found for evanescent waves in a defect-free photonic crystal waveguide, is a generic feature and exists in the Anderson regime as well, i.e., in the presence of disorder. Our finding reveals a scaling behavior of the localization length in terms of the disorder strength, as well as a summation rule of the inverse localization length in terms of the density of states in different bands. Most interesting, the latter indicates the possibility of having two localization minima inside a band gap, if this band gap is formed by two flat bands such as in a double-sided Lieb lattice.Comment: 8 pages, 9 figure

Evaluation "Risk analyses of agroparks"

Dit TransForum project richt zich op analyse van de onzekerheden en mogelijkheden van agroparken. Dit heeft geleid tot een risicomodel dat de kwalitatieve en/of kwantitatieve onzekerheden van een agropark project in kaart brengt. Daarmee kunnen maatregelen en managementstrategiën worden geïdentificeerd. Zo worden potentiële risico's omgezet in hanteerbare mogelijkheden

Henry Y. H. Zhao. The uneasy narrator : Chinese fiction from the traditional to the modern

This article reviews the book The Uneasy Narrator: Chinese Fiction from the Traditional to the Modern , written by Henry Y.H. Zhao