Exciton transfer in DNA

Fluorescent risetimes are measured to be less than 20 ps for DNA-acridine orange complexes. This result is consistent with a rapid non-radiative depletion of the excited singlet state of DNA due to exciton-phonon interactions.     

Hermitian pencils with a cubic minimal polynomial

Let A be an n × n complex matrix and write A = H + iK, where H and K are Hermitian matrices. We show that if the minimal polynomial of the pencil xH + yK has degree 3, then there is a unitary matrix U such that U^-1AU is block diagonal with blocks of size 3 × 3 or smaller. This is a special case of a conjecture made by Kippenhahn in 1951.     

A note on node aggregation and Benders' decomposition

Node aggregation methods have been previously studied as a means for approximating large scale transportation problems. In this paper, we show how the approximations inherent in Benders' decomposition method can be combined with node aggregation in optimizing large scale capacitated plant location problems. This research was supported by the National Science Foundation under Grant No. ECS-8117105.