We develop a natural generalization of vector-valued frame theory, which we term operator-valued frame theory, using operator-algebraic methods. This extends work of the second author and D. Han which can be viewed as the multiplicity one case and extends to higher multiplicity their dilation approach. We prove several results for operator-valued frames concerning duality, disjointedness, compl...

We construct a decomposition of the identity operator on the sphere S as a sum of smooth orthogonal projections subordinate to an open cover of S. We give applications of our main result in the study of function spaces and Parseval frames on the sphere.

This paper proposes that the identification of constituents, which is the core problem in grammar induction, can be accomplished by a simple constituency criterion in linguistics: a word/tag sequence which can occur as a fragment is a constituent. Experiment results show that grammar induction by distributional clustering augmented with this criterion achieves good PARSEVAL scores and improves ...

• Pre-Hilbert spaces: definition • Cauchy-Schwarz-Bunyakowski inequality • Example: spaces ` • Triangle inequality, associated metric, continuity issues • Hilbert spaces, completions, infinite sums • Minimum principle • Orthogonal projections to closed subspaces • Orthogonal complements W⊥ • Riesz-Fischer theorem on linear functionals • Orthonormal sets, separability • Parseval equality, Bessel...