In this paper we describe a method for computing matrix CR bounds for image reconstruction problems using an iterative algorithm that avoids the intractable inversion of the Fisher matrix required by direct methods. The algorithm produces a close approximation to the CR bound requiring only O(n 2) oating point operations per pixel of interest ; an order of magnitude savings relative to the O(n ...

We investigate iterative implementations of linear receivers for spatial diversity channels. This work has been motivated by recent results concerning iterative implementations of linear multiuser receivers, under the assumption of long random sequences. We explore implementation issues for such iterative methods for f inite system dimensions. We consider the Chebyshev iteration using estimates...

Two techniques are presented for noninvasively determining the intensity field of high-intensity focused ultrasound transducers in a liquid medium. The techniques are based upon the streaming velocity induced in the liquid by the absorbed ultrasound beam. The approaches are similar to an iterative streaming method previously reported, but the present approaches are "direct:" The differential op...

The map-making step of Cosmic Microwave Background data analysis involves linear inversion problems which cannot be performed by a brute force approach for the large timelines of today. We present in this article optimal vector-only map-making methods, which are an iterative COBE method, a Wiener direct filter and a Wiener iterative method. We apply these methods on diverse simulated data, and ...

and Applied Analysis 3 where R is the set of all real numbers; in particular, J(−x) = −J(x) for all x ∈ E ([28]). We say that a Banach space E has a weakly sequentially continuous duality mapping if there exists a gauge function φ such that the duality mapping Jφ is single valued and continuous from the weak topology to the weak topology; that is, for any {xn} ∈ E with xn ⇀ x, Jφ(xn) ∗ ⇀ Jφ(x)....

Direct methods for restoration of images blurred by motion are analyzed and compared. The term direct means that the considered methods are performed in a one-step fashion without any iterative technique. The blurring point-spread function is assumed to be unknown, and therefore the image restoration process is called blind deconvolution. What is believed to be a new direct method, here called ...

Suppose that K is a nonempty closed convex subset of a real uniformly convex and smooth Banach space E with P as a sunny nonexpansive retraction. Let T1,T2 : K → E be two weakly inward and asymptotically nonexpansive mappings with respect to P with sequences {Kn},{ln} ⊂ [1,∞), limn→∞kn = 1, limn→∞ln = 1, F(T1)∩ F(T2) = {x ∈ K : T1x = T2x = x} =∅, respectively. Suppose that {xn} is a sequence in...

begin{abstract} In this paper, we introduce an iterative method for amenable semigroup of non expansive mappings and infinite family of non expansive mappings in the frame work of Hilbert spaces. We prove the strong convergence of the proposed iterative algorithm to the unique solution of a variational inequality, which is the optimality condition for a minimization problem. The results present...

It is of interest in various contexts to nd approximate feasible points to problems that have equality, inequality and bound constraints. For example, in exhaustive search algorithms for global optimization , it is of interest to construct bounds around approximate feasible points, within which a true feasible point is proven to exist. In such exhaustive search algorithms, the approximate feasi...

A method for efficiently planning one-dimensional pop-limited trajectories is presented, along with a direct method for synchronizing trajectories across multiple dimensions. This heuristic is designed for a double integrator utilizing acceleration commands passed through a 4th-order cascaded filter, the model for which is presented along with the system solution for an arbitrary time step and ...