An equiangular tight frame (ETF) is a sequence of vectors in Hilbert space that achieves equality the Welch bound and so has minimal coherence. More generally, an equichordal fusion (ECTFF) equi-dimensional subspaces Conway, Hardin Sloane’s simplex bound. Every ECTFF type optimal Grassmannian code, is, packing space. We construct ECTFFs by exploiting new relationships between known ETFs. Harmon...

Characterizing the performance of Optical Character Recognition (OCR) systems is crucial for monitoring technical progress, predicting OCR performance, providing scientiic explanations for system behavior and identifying open problems. While research has been done in the past to compare the performances of OCR systems, all methods assume that the accuracies achieved on individual documents in a...