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Evseev I.G.,Federal University of Technology of Parana | Schelin H.R.,Federal University of Technology of Parana | Paschuk S.A.,Federal University of Technology of Parana | Milhoretto E.,Federal University of Technology of Parana | And 6 more authors.
Applied Radiation and Isotopes | Year: 2010

Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation. © 2009 Elsevier Ltd. All rights reserved. Source


Rivas F.R.,Clinica Central Cira Garcia | Mesa G.,CEADEN
IFMBE Proceedings | Year: 2013

This work attempts to develop a functional prototype for stimulating biological systems with visible light. This system consists of different technologies (Power PSoC, EZ-Color, PrISM, CapSense) which help in controlling radiation parameters. Each of them have been implemented taking advantage of the on-chip programmable device CY8CLED04 of Cypress Semiconductor and are controlled through PSoC Express 3 software. This software offers an easily adaptable visual interface that permits the development of applications dynamically. PSoC Express 3 makes use of the chromatic diagram CIE 1931 to select the different wavelength to stimulate which are generated by three high brightness light emission diodes (HB-LEDs): red, green and blue (RGB). This light passes through a diffuser that favors the homogeneity of the resulting radiation. © 2013 Springer. Source


Cerello P.,National Institute of Nuclear Physics, Italy | Christian Cheran S.,National Institute of Nuclear Physics, Italy | Bagnasco S.,National Institute of Nuclear Physics, Italy | Bellotti R.,University of Bari | And 11 more authors.
Pattern Recognition | Year: 2010

3-D object segmentation is an important and challenging topic in computer vision that could be tackled with artificial life models. A Channeler Ant Model (CAM), based on the natural ant capabilities of dealing with 3-D environments through self-organization and emergent behaviours, is proposed. Ant colonies, defined in terms of moving, pheromone laying, reproduction, death and deviating behaviours rules, is able to segment artificially generated objects of different shape, intensity, background. The model depends on few parameters and provides an elegant solution for the segmentation of 3-D structures in noisy environments with unknown range of image intensities: even when there is a partial overlap between the intensity and noise range, it provides a complete segmentation with negligible contamination (i.e., fraction of segmented voxels that do not belong to the object). The CAM is already in use for the automated detection of nodules in lung Computed Tomographies. © 2009 Elsevier Ltd. All rights reserved. Source


Garcia-Basabe Y.,University of Habana | Garcia-Basabe Y.,University of Matanzas | Gomez A.,University of Guelph | Rodriguez-Iznaga I.,University of Habana | And 4 more authors.
Journal of Physical Chemistry C | Year: 2010

The location of extra-framework cations in low-silica zeolites is determined from in-house X-ray powder diffraction pattern by a successful implementation of a newly developed methodology. The method combines reciprocal and direct space methods plus a cost function that accounts for simultaneous fit of the chemical composition and the X-ray diffractogram. We demonstrated that the iterative combination of relaxation methods (Monte Carlo exploration and lattice energy minimization) helps to improve the structural refinement. The methodology is successfully applied to the study of natural clinoptilolite samples enriched with Ni and Co; in both cases, two different cation sites were found octahedrally coordinated to water molecules. The most populated site is located in the center of the A channel, while the second one is found in the window of the B channel. This result was validated using XANES and EXAFS spectroscopies. © 2010 American Chemical Society. Source


Camarlinghi N.,University of Pisa | Camarlinghi N.,National Institute of Nuclear Physics, Italy | Gori I.,Bracco Imaging Spa | Retico A.,National Institute of Nuclear Physics, Italy | And 14 more authors.
International Journal of Computer Assisted Radiology and Surgery | Year: 2012

Purpose The aim of this work is to evaluate the potential of combining different computer-aided detection (CADe) methods to increase the actual support for radiologists of automated systems in the identification of pulmonary nodules in CT scans. Methods The outputs of three different CADe systems developed by researchers of the Italian MAGIC-5 collaboration were combined. The systems are: the CAMCADe (based on a Channeler-Ant-Model which segments vessel tree and nodule candidates and a neural classifier), the RGVPCADe (a Region-Growing- Volume-Plateau algorithm detects nodule candidates and a neural network reduces false positives); the VBNACADe (two dedicated procedures, based respectively on a 3D dot-enhancement algorithm and on intersections of pleura surface normals, identifies internal and juxtapleural nodules, and a Voxel-Based-Neural-Approach reduces false positives. A dedicated OsiriX plugin implemented with the Cocoa environments of MacOSX allows annotating nodules and visualizing singles and combined CADe findings. Results The combined CADe has been tested on thin slice (lower than 2 mm) CTs of the LIDC public research database and the results have been compared with those obtained by the single systems. The FROC (Free Receiver Operating Characteristic) curves show better results than the best of the single approaches. Conclusions Has been demonstrated that the combination of different approaches offers better results than each single CADe system. A clinical validation of the combined CADe as second reader is being addressed bymeans of the dedicated OsiriX plugin. © 2011 CARS. Source

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