Abstract The detected samples of ICT have variable sizes. Different scanning models and corresponding reconstruction algorithms are designed to enlarge the field of view under the condition of a detector of fixed size, such as rotation off-centered、detector displaced. Generally, rebinning method is applied to rotation off-centered scanning model. Fan beam projections are rebinned to parallel be...

Mean shift algorithm is widely used in 2D images. In this paper a novel 3D corresponding control points estimation using mean shift algorithm is proposed. This algorithm is not a simple extension from 2D to 3D, but computes the probability density function in each slice of the search region and connects them into a whole density function smoothed by Gaussian function. And then we calculate and ...

In this paper, we apply the homotopy perturbation transform method (HPTM) to obtain the solution of linear and nonlinear Schrödinger equations. The HPTM is a combined form of the Laplace transform method with the homotopy perturbation method. This method finds the solution without any discretization or restrictive assumptions and avoids the round-off errors. The fact that this technique solves ...

This document describes a gravitational N-body integration algorithm incorporating the following features: (1) it is exactly (neglecting rounding errors) time-reversible, (2) angular and linear momentum are conserved, (3) smooth switching functions are used to split potential terms into local and weak parts so that weaker long-range forces are evaluated relatively rarely and close interactions ...

We consider the problem of inferring the probability distribution associated with a language, given data consisting of an infinite sequence of elements of the languge. We do this under two assumptions on the algorithms concerned: (i) like a real-life algorothm it has round-off errors, and (ii) it has no roundoff errors. Assuming (i) we (a) consider a probability mass function of the elements of...

This paper describes modifications to many of the standard algorithms used in computing eigenvalues and eigenvectors of matrices. These modifications can dramatically increase the performance of the underlying software on high-performance computers without resorting to assembler language, without significantly influencing the floating-point operation count, and without affecting the roundoff-er...

A restarted nonsymmetric Lanczos algorithm is given for computing eigenvalues and both right and left eigenvectors. The restarting limits the storage so that finding eigenvectors is practical. Restarting also makes it possible to deal with roundoff error in new ways. We give a scheme for avoiding near-breakdown and discuss maintaining biorthogonality. A system of linear equations can be solved ...

A new criterion for selective reorthogonalization in the Gram-Schmidt procedure is given. We establish its comportment in presence of rounding errors when the criterion is used with modified Gram-Schmidt algorithm and show counter-example matrices which prove that standard criteria are not always valid. Experimentally, our criterion is fine also for the classical Gram-Schmidt algorithm with reo...

Front-page news selection is the task of finding important news articles in news aggregators. In this study, we examine news selection for public front pages using raw text, without any meta-attributes such as click counts. A novel algorithm is introduced by jointly considering the importance and diversity of selected news articles and the length of front pages. We estimate the importance of ne...

A timing recovery algorithm is introduced that operates with less than two samples per symbol and provides an enormous complexity reduction. The complexity reduction is due to a synergy with the already existing Fourier transforms in a coherent receiver, an avoidance of terms that are dominated by noise, and a complete elimination of multiplications. A simulation and an experiment with a single...