Search results for "image processing"
showing 10 items of 3285 documents
Contributions to the physical and experimental validation of a simultaneous PET/MRI system dedicated to small animal imaging
2020
Simultaneous PET/MRI is a dynamic research field of both medical and preclinical domains. The ability of integrated systems to acquire the highly complementarity MR morphological and PET functional data in a single examination paves the way to innovative applications. The hereby document presents a series of experimentations dealing with the performance evaluation and the experimental in vivo capacities of such a device. Physical measurements were implemented based on international standards or inspired by articles of reference. The evaluated system consists of a compact SiPM-based PET subsystem fully integrated in a 7 T preclinical MRI based on the dry magnet technology. Experimentations s…
Detection and Discrimination of Inter-Turn Short Circuit and Demagnetization Faults in PMSMs Based on Structural Analysis
2021
This paper presents a fault diagnosis method based on structural analysis of permanent magnet synchronous motors (PMSMs), focusing on detecting and discriminating two of the most common faults in PMSMs, namely demagnetization and inter-turn short circuit faults. The structural analysis technique uses the dynamic mathematical model of the PMSM in matrix form to evaluate the system’s structural model. After obtaining the analytical redundancy using the over-determined part of the system, it is divided into redundant testable sub-models. Four structured residuals are designed to detect and isolate the investigated faults, which are applied to the system in different time intervals. Finally, th…
Teaching GP to program like a human software developer
2019
Program synthesis is one of the relevant applications of GP with a strong impact on new fields such as genetic improvement. In order for synthesized code to be used in real-world software, the structure of the programs created by GP must be maintainable. We can teach GP how real-world software is built by learning the relevant properties of mined human-coded software - which can be easily accessed through repository hosting services such as GitHub. So combining program synthesis and repository mining is a logical step. In this paper, we analyze if GP can write programs with properties similar to code produced by human software developers. First, we compare the structure of functions generat…
Pettis integrability of fuzzy mappings with values in arbitrary Banach spaces
2017
Abstract In this paper we study the Pettis integral of fuzzy mappings in arbitrary Banach spaces. We present some properties of the Pettis integral of fuzzy mappings and we give conditions under which a scalarly integrable fuzzy mapping is Pettis integrable.
Measurement of edge residual stresses in glass by the phase-shifting method
2011
Abstract Control and measurement of residual stress in glass is of great importance in the industrial field. Since glass is a birefringent material, the residual stress analysis is based mainly on the photoelastic method. This paper considers two methods of automated analysis of membrane residual stress in glass sheets, based on the phase-shifting concept in monochromatic light. In particular these methods are the automated versions of goniometric compensation methods of Tardy and Senarmont. The proposed methods can effectively replace manual methods of compensation (goniometric compensation of Tardy and Senarmont, Babinet and Babinet–Soleil compensators) provided by current standards on th…
Review of RGB photoelasticity
2015
Abstract Automatic methods of photoelasticity have had a significant progress with the development of automatic acquisition and image processing methods. This article concerns RGB photoelasticity, which allows the determination of the photoelastic retardation using, usually, a single acquisition of the isochromatic fringes in white light by a colour camera. In particular, the article presents an overview of the main characteristics of RGB photoelasticity that is influence of the quarter-wave plate error, number of acquisitions, type of light source, determination of low and high fringe orders, methods for searching the retardation, scanning procedures, calibration on a material different fr…
Full-field automatic evaluation of an isoclinic parameter in white light
1997
In this paper, a technique for full-field evaluation of the isoclinic parameter is presented. It combines the phase-shifting method with true color imaging technology to minimize the interaction between isoclinic and isochromatic fringes. The paper also shows how the proposed technique can be suitably integrated with known methods for evaluating the retardations. Furthermore, a digital algorithm for filtering wrapped phase data obtained by general phase-shifting techniques is presented.
Photoelastic Analysis of Edge Residual Stresses in Glass by Automated “Test Fringes” Methods
2011
Since the glass is a birefringent material, the analysis of residual stress in glass is usually carried out by means of photoelastic methods. This paper considers the automation of the “test fringes” method which is based on the use of a Babinet compensator or of a beam subjected to bending. In particular, two automated methods are proposed: the first one is based on the use of the centre fringe method in monochromatic light and the second one is based on the use of RGB photoelasticity in white light. The proposed methods have been applied to the analysis of membranal residual stresses in some tempered glasses, showing that they can effectively replace manual methods of photoelastic analysi…
Phase shifting photoelasticity in white light
2007
The availability of image acquisition systems has led to the development of digital photoelasticity both in monochromatic and white light. In particular white light has been used mainly with the following methods: Spectral Content Analysis, RGB photoelasticity and phase shifting photoelasticity. Phase shifting photoelasticity in the colour domain has been used effectively for the determination of the isoclinic parameter in order to reduce the influence of the isochromatic fringes. The method has been also proposed for the determination of the isochromatic fringe order. This paper concerns the general characteristics of phase shifting photoelasticity in the colour domain. Special attention i…
RGB photoelasticity applied to the analysis of membrane residual stress in glass
2011
The measurement of residual stresses is of great relevance in the glass industry. The analysis of residual stress in glass is usually made by photoelastic methods because glass is a photoelastic material. This paper considers the determination of membrane residual stresses in glass plates by automatic digital photoelasticity in white light (RGB photoelasticity). The proposed method is applied to the analysis of membrane residual stresses in some tempered glass. The proposed method can effectively replace manual methods based on the use of white light, which are currently provided by some technical standards.