recent developments in nanostructured products draw considerable attention to ultrafine grained materials. these materials are normally manufactured by different severe plastic deformation (spd) methods. in the present study, analytical models and finite element method (fem) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ecap). in additio...

the kaolinitic clays have been exploited for more than a hundred years, in the western part of the charentes basin, france, and belong to a paleo-deltaic network. the recent deposits are relatively richer in alumina in comparison with the older ones. the genesis of the kaolin deposits of the charentes basin follows simple geological rules, but their detailed geometry has a great complexity, rei...

background: accurate voxel phantom is needed for dosimetric simulation in radiation therapy for malignant tumors in female pelvic region. however, most of the existing voxel phantoms are constructed on the basis of caucasian or non-chinese population. materials and methods: a computational framework for constructing female pelvic voxel phantom for radiation dosimetry was performed based on chin...

Discrete-event simulation based optimization is the process of finding the optimum design of a stochastic system when the performance measure(s) could only be estimated via simulation. Randomness in simulation outputs often challenges the correct selection of the optimum. We propose an algorithm that merges Ranking and Selection procedures with a large class of random search methods for continu...

BACKGROUND Monte Carlo simulations provide accurate models of nuclear medicine imaging systems as they can properly account for the full physics of photon transport. The accuracy of the model included in the maximum-likelihood-expectation-maximization (ML-EM) reconstruction limits the overall accuracy of the reconstruction results. In this paper, we present a Monte Carlo-based ML-EM reconstruct...

BACKGROUND The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method for further assisting the visual interpretation and to test the concept using simulated MPS images as w...