Myocardial perfusion SPECT is one of the most common imaging techniques performed in nuclear medicine departments. To avoid misleading interpretation, it is necessary to address the quality control and technical problems. The truncation artifact occurs when the patient size is large relative to the field of view of the camera, causing false perfusion defects in the LV myocardium, misinterpreted...

Recently introduced combined PET/MR scanners need to handle the specific problem that a limited MR field of view sometimes truncates arm or body contours, which prevents an accurate calculation of PET attenuation correction maps. Such maps of attenuation coefficients over body structures are required for a quantitatively correct PET image reconstruction. This paper addresses this problem by pre...

We consider the problem of computing stable/unstable manifolds attached to periodic orbits of maps, and develop quasi-numerical methods for polynomial approximation of the manifolds to any desired order. The methods avoid function compositions by exploiting an idea inspired by multiple shooting schemes for periodic orbits. We consider a system of conjugacy equations which characterize chart map...

This paper addresses model reduction and extends balanced truncation to the class of switched affine systems with endogenous switching. The switched affine system is rewritten as a switched linear one with state resets that account for the affine terms. Balanced truncation can then be applied to each mode dynamics, independently. As a result, different reduced state vectors are associated with ...

In this paper, the concept of intuitionistic fuzzy mapping as a generalization of fuzzy mapping is presented, and its' relationship with intuitionistic fuzzy relations is derived. Moreover, some basicoperations of intuitionistic fuzzy mappings are defined, hence we can conclude that all of intuitionistic fuzzy mappings constitute a soft algebrawith respect to these operations. Afterwards, the A...

The Diierential Algebraic Methods, a natural tool for the description and determination of the solution of diierential equations, have proven useful for the computation of aberrations of any desired order in any particle optical system. Besides conventional symplectic systems based on strongly or weakly focusing elements including fringe elds, they also readily allow the treatment of spin dynam...

The effect of noise on self-similar set is studied. The iteratie procedure used to generate the self-similar set is moidified by adding a stochastic variable to the diameter of generating sets at each iteration. The noise may causes the generating set to collapse to a point. Distribution functions are found describing the probability that any generating set collapse. The effect of chaotic distu...

We study different strategies for the truncation of computational domains in the simulation of eddy current probes of elongated axisymmetric tubes. For axial fictitious boundaries, an exact Dirichlet-to-Neumann (DtN) map is proposed and mathematically justified via the analysis of a nonselfadjoint spectral problem. We rely of results from the spectral theory of compact perturbations of selfadjo...

A k-orbit map is a map with k flag-orbits under the action of its automorphism group. We give a basic theory of k-orbit maps and classify them up to k 6 4. “Hurwitz-like” upper bounds for the cardinality of the automorphism groups of 2orbit and 3-orbit maps on surfaces are given. Furthermore, we consider effects of operations like medial and truncation on k-orbit maps and use them in classifyin...

In this paper, we first define an equivalence relation on the sequence space $\Sigma _{2}$. Then equip quotient set _{2}/_{\sim}$ with a metric $d_1$. We also determine isometry map between spaces $(\Sigma _{2}/_{\sim},d_1)$ and $([0,1],d_{eucl})$. Finally, investigate symmetry conditions respect to some points compare truncation errors for computations which is obtained by metrics $d_{eucl}$