Search results for "Computer-aided"
showing 10 items of 416 documents
Thermal buckling optimization of composite laminates by evolution strategies
2000
Abstract Thermal buckling optimization of laminated composite plates subject to a temperature rise is presented in this paper. Aerospace structures require such components that are able to withstand the external environment loads without loss of stability. The discrete optimal design problem, formulated under strain and ply contiguity constraints is solved using evolution strategies, a guided random-search method. Two different constraint handling methods are investigated and compared: the disregarding infeasible solutions and the classical penalty function approach. The results are also compared with an exact enumerative study conducted on the problem, showing the effectiveness and perform…
Accuracy of 4 digital scanning systems on prepared teeth digitally isolated from a complete dental arch
2018
Abstract Statement of problem The accuracy of digital scanners is acceptable for scanning a complete dental arch. However, whether that accuracy is sufficient for only 1 tooth within the dental scan of a complete dental arch is unclear. Purpose The purpose of this in vitro study was to evaluate and compare the accuracy of 4 intraoral scanners on a complete dental arch and on prepared teeth digitally isolated from the digital scan in terms of trueness and precision. Material and methods A model of a complete dental arch with tooth preparations was scanned 40 times with each of the 4 digital scanners. Their accuracy was evaluated by using 3-dimensional (3D) software to compare the test models…
A visual framework to create photorealistic retinal vessels for diagnosis purposes
2020
The methods developed in recent years for synthesising an ocular fundus can be been divided into two main categories. The first category of methods involves the development of an anatomical model of the eye, where artificial images are generated using appropriate parameters for modelling the vascular networks and fundus. The second type of method has been made possible by the development of deep learning techniques and improvements in the performance of hardware (especially graphics cards equipped with a large number of cores). The methodology proposed here to produce high-resolution synthetic fundus images is intended to be an alternative to the increasingly widespread use of generative ad…
A distributed genetic algorithm for restoration of vertical line scratches
2008
This paper reports a distributed algorithm for the restoration of still frames corrupted by vertical line scratches. The restoration is here approached as an optimisation problem, and is solved using an ad-hoc Genetic Algorithm. The distributed algorithm is designed following a pipeline logical structure. The front end is a network of standard workstations with heterogeneous operating systems. The quality of image is appreciable and the computational time is quite low with respect the sequential version.
A solution process for simulation-based multiobjective design optimization with an application in the paper industry
2014
In this paper, we address some computational challenges arising in complex simulation-based design optimization problems. High computational cost, black-box formulation and stochasticity are some of the challenges related to optimization of design problems involving the simulation of complex mathematical models. Solving becomes even more challenging in case of multiple conflicting objectives that must be optimized simultaneously. In such cases, application of multiobjective optimization methods is necessary in order to gain an understanding of which design offers the best possible trade-off. We apply a three-stage solution process to meet the challenges mentioned above. As our case study, w…
Computer-aided diagnosis in digital mammography: comparison of two commercial systems
2014
Aim: Within this work, a comparative analysis of two commercial computer-aided detection or diagnosis (CAD) systems, CyclopusCAD® mammo (v. 6.0) produced by CyclopusCAD Ltd (Palermo, Italy) and SecondLook® (v. 6.1C) produced by iCAD Inc. (OH, USA) is performed by evaluating the results of both systems application on an unique set of mammographic digital images routinely acquired in a hospital structure. Materials & methods: The two CAD systems have been separately applied on a sample set of 126 mammographic digital cases, having been independently diagnosed by two senior radiologists. According to the human diagnosis, the cases in the sample reference set are divided into 61 negatives and 6…
Computer-Assisted Classification Patterns in Autoimmune Diagnostics: The AIDA Project.
2016
International audience; Antinuclear antibodies (ANAs) are significant biomarkers in the diagnosis of autoimmune diseases in humans, done by mean of Indirect ImmunoFluorescence (IIF) method, and performed by analyzing patterns and fluorescence intensity. This paper introduces the AIDA Project (autoimmunity: diagnosis assisted by computer) developed in the framework of an Italy-Tunisia cross-border cooperation and its preliminary results. A database of interpreted IIF images is being collected through the exchange of images and double reporting and a Gold Standard database, containing around 1000 double reported images, has been settled. The Gold Standard database is used for optimization of …
Introduction to molecular topology: basic concepts and application to drug design.
2012
In this review it is dealt the use of molecular topology (MT) in the selection and design of new drugs. After an introduction of the actual methods used for drug design, the basic concepts of MT are defined, including examples of calculation of topological indices, which are numerical descriptors of molecular structures. The goal is making this calculation familiar to the potential students and allowing a straightforward comprehension of the topic. Finally, the achievements obtained in this field are detailed, so that the reader can figure out the great interest of this approach.
Twofold coordinated Ge defects induced by gamma-ray irradiation in Ge-doped SiO2
2008
We report an experimental study by photoluminescence, optical absorption and Electron Paramagnetic Resonance measurements on the effects of exposure of Ge-doped amorphous SiO2 to gamma ray radiation at room temperature. We have evidenced that irradiation at doses of the order of 1 MGy is able to generate Ge-related defects, recognizable from their optical properties as twofold coordinated Ge centers. Until now, such centers, responsible for photosensitivity of Ge-doped SiO2, have been induced only in synthesis procedures of materials. The found result evidences a role played by gamma radiation in generating photosensitive defects and could furnish a novel basis for photosensitive pattern wr…
The FiR 1 photon beam model adjustment according to in-air spectrum measurements with the Mg(Ar) ionization chamber.
2014
Abstract The mixed neutron–photon beam of FiR 1 reactor is used for boron–neutron capture therapy (BNCT) in Finland. A beam model has been defined for patient treatment planning and dosimetric calculations. The neutron beam model has been validated with an activation foil measurements. The photon beam model has not been thoroughly validated against measurements, due to the fact that the beam photon dose rate is low, at most only 2% of the total weighted patient dose at FiR 1. However, improvement of the photon dose detection accuracy is worthwhile, since the beam photon dose is of concern in the beam dosimetry. In this study, we have performed ionization chamber measurements with multiple b…