A matrix A is called completely positive if it can be decomposed as A = BBT with an entrywise nonnegative matrix B. The set of all such matrices is a convex cone which plays a role in certain optimization problems. A characterization of the interior of this cone is provided.

A matrix A is called completely positive if it can be decomposed as A = BBT with an entrywise nonnegative matrix B. The set of all such matrices is a convex cone which plays a role in certain optimization problems. A characterization of the interior of this cone is provided.

Fuchs [6] called a partially-ordered integral domain, say D, division closed if it has the property that whenever a > 0 and ab > 0, then b > 0. He showed that if D is a lattice-ordered division closed field, then D is totally ordered. In fact, it is known that for a lattice-ordered division ring, the following three conditions are equivalent: a) squares are positive, b) the order is total, and ...

Let K be a closed convex cone with the nonempty interior in a real Banach space and cc(K) denote the family of all nonempty convex compact subsets of K. If {F t : t ≥ 0} is a concave iteration semigroup of continuous linear set-valued functions F t : K → cc(K) with F (x) = {x} for x ∈ K, then DtF (x) = F (G(x)) for x ∈ K and t ≥ 0, where DtF (x) denotes the Hukuhara derivative of F (x) with res...

PURPOSE To determine the functional defects in two male patients with progressive cone dystrophy and hybrid L-M cone pigment genes. METHODS Clinical evaluation, standard electroretinography, and electrooculography were performed in two affected patients and two family members. Measurements of spectral sensitivity and transient tritanopia were made in both patients. RESULTS In the patients, ...

Estimates of the density spectrum of the macular pigment (Wyszecki G, Stiles WS. Color Science: Concepts and Methods. Quantitative Data and Formulas. 1st ed. New York: Wiley, 1967); (Vos JJ. Literature review of human macular absorption in the visible and its consequences for the cone receptor primaries. Institute for Perception. Soesterberg, The Netherlands, 1972) are partially based on the di...