Omar Mansouri - Academia.edu (original) (raw)

Papers by Omar Mansouri

ITM Web of Conferences, 2022

One of the most common medical imaging methods is a chest x-ray, as it contributes to the early d... more One of the most common medical imaging methods is a chest x-ray, as it contributes to the early detection of lung cancer compared to other methods. this work presents the use of a generative adversarial network to perform lung chest x-ray image segmentation. The network is two frameworks neural (generator and discriminator). In our work the generator is trained to generate a mask for the input of a given original image, the discriminator distinguishes between the original mask and the generated mask, the final objective is to generate masks for the input. The model is trained and evaluated, well generalized experimental results of the JSRT dataset reveal that the proposed model can a dice score of 0.9778, which is better than other reported state-of-the-art results.

Perhaps the most straightforward classifier in the arsenal or machine learning techniques is the ... more Perhaps the most straightforward classifier in the arsenal or machine learning techniques is the Nearest Neighbour Classifier-classification is achieved by identifying the nearest neighbours to a query example and using those neighbours to determine the class of the query. This approach to classification is of particular importance because issues of poor run-time performance is not such a problem these days with the computational power that is available. This paper presents an overview of techniques for Nearest Neighbour classification focusing on; mechanisms for assessing similarity (distance), computational issues in identifying nearest neighbours and mechanisms for reducing the dimension of the data. This paper is the second edition of a paper previously published as a technical report [14]. Sections on similarity measures for time-series, retrieval speed-up and intrinsic dimensionality have been added. An Appendix is included providing access to Python code for the key methods.

Due to the absence of guidelines for evaluating bonded anchors exposed to fire, only the existing... more Due to the absence of guidelines for evaluating bonded anchors exposed to fire, only the existing method for mechanical anchors (without resin) is applicable. This method only covers steel failure mode for bonded anchors. Pull-out failure mode occurs more often than other failure modes for bonded anchors at high temperatures. This paper presents a numerical study of different parameters linked to the existing evaluation method by means of 3D heat transfer analysis. First, the model is validated for experimental data in the literature. Then, other parameters are investigated to assess their influence on the precision of pull-out fire tests. Studied parameters are: embedded part of the anchor, extended length of the anchor and concrete element insulation. Results show that the embedded depth has a significant influence on temperature profiles along the bond. Moreover, the external length of the anchor influences temperature profiles, but not beyond lengths beyond 20 mm from the concre...

In this paper, we will present an analytical modelling of a one-turn coil dedicated to magnetic-p... more In this paper, we will present an analytical modelling of a one-turn coil dedicated to magnetic-pulse technologies. The goal is to be able to determine the main useful parameters of an inductor by calculating the magnetic vector potential “A” diffusion. The concerned parameters are electromagnetic (electromagnetic fields, magnetic flux and electric current densities), electrical (resistance and inductance, maximum field coefficient) and electromechanical (Lorentz force density and maximum force coefficient). The results obtained will then be compared to numerical computations performed onto some test cases. In order to get an approximate but robust analytical solution, it is proposed to assume an axial symmetry and to solve the problem in the harmonic working condition before studying the transient state.

Cette these est composee de deux volets. Le premier volet est consacre a l’etude et la realisatio... more Cette these est composee de deux volets. Le premier volet est consacre a l’etude et la realisation d’une boucle d’autopilotage sans capteur mecanique d’un actionneur electromagnetique direct applique aux milieux confines. Le but est de supprimer toute la chaine cinematique afin de transmettre directement le couple a la charge mecanique au travers d’une paroi amagnetique de confinement. Les applications visees concernent toutes les industries a ambiance controlee ou on doit soit proteger l’homme de la matiere (nucleaire), soit proteger la matiere de l’homme (pharmaceutique, cosmetique, agroalimentaire). Cet actionneur doit etre adapte a une situation d’exploitation preexistante en traitement de dechets radioactifs. Afin d’optimiser le couple electromagnetique transmis, de controler la vitesse et d’eviter le decrochage, nous avons mis au point un nouveau capteur statique de position. Ce capteur inductif est compose de trois enroulements disposes dans la partie naturelle. Un circuit el...

Structural Concrete, 2021

Construction and Building Materials, 2020

Abstract Digital construction of concrete elements using 3D printing technology has been undergoi... more Abstract Digital construction of concrete elements using 3D printing technology has been undergoing an exponential growth in terms of research activities and demonstration projects. Though, most researches focused on the behavior of the cementitious materials used in 3D printing, without deeply immersing in the reinforcement of printed elements. In this paper, a detailed experimental program is presented to characterize the quality of the bond developed between concrete and steel bars through a series of pull-out tests. These tests are performed over printed and non-printed samples as well. When printed, the layers orientation, whether parallel or perpendicular to the steel bar is taken into consideration. Hence, it was found that a highly thixotropic material did not undermine the developed bond between printed concrete and rebar. In addition, vibrated concrete (non-printed) gave better resistance to pull-out stresses succeeded by the parallel then the perpendicular samples. Yet, the overall performance of 3D printed concrete in terms of the bond generated with steel could be rated as satisfactory.

Materials, 2021

Post-installed rebars (PIRs) using mortar can offer bond strength at ambient temperature equal or... more Post-installed rebars (PIRs) using mortar can offer bond strength at ambient temperature equal or higher to that of cast-in place rebars. However, high temperatures have the effect of weakening the bond, typically governed by the chemical and physical properties of the mortar which is often sensitive to temperature increase. Therefore, the behavior of PIRs in a fire situation becomes vulnerable. Moreover, after exposure of PIRs to high temperature, the heat transfer continues during the post-fire phase, which might endanger the construction after a fire event. In order to evaluate the evolution of the pull-out capacity during fire, Pinoteau et al. have developed the bond resistance integration method (Pinoteau’s RIM) to predict the bond resistance value of a rebar subjected to various temperatures in accordance with the fire exposure curves. Therefore, accurate temperature profiles during the post-fire phase are needed to ensure a correct calculation of the post-fire behavior of the...

Applied Sciences, 2021

Fire design of cast-in place and post-installed anchors in concrete under fire is covered by EN 1... more Fire design of cast-in place and post-installed anchors in concrete under fire is covered by EN 1992-4, Annex D, allowing steel- and concrete-related failure modes of anchors to be calculated. This informative annex of EN 1992-4 is limited to cast-in place or mechanical anchors, whereas post-installed adhesive anchors remain out of its scope. This paper presents a study of the applicability of the more flexible resistance integration method (RIM), proposed originally for the design of the pull-out resistance of post-installed reinforcement (PIR) by Pinoteau, on bonded anchors in uncracked concrete. This method is validated from a comparison of test results obtained from two research projects conducted at CSTB and TU Kaiserslautern on bonded anchors in uncracked concrete under ISO 834-1 fire conditions. The data considered include tests conducted on anchor sizes from M8-M30 using three different adhesives (two epoxy adhesives and one cementitious mortar). Design of the pull-out resis...

International Journal of Applied Electromagnetics and Mechanics, 2019

Frattura ed Integrità Strutturale, 2019

In this paper an additional criterion was introduced to evaluate the composite repair systems usi... more In this paper an additional criterion was introduced to evaluate the composite repair systems using the limit load analysis. The plastic collapse pressure of API 5L X65 PSL2 steel pressure vessel structure with crack defect is numerically investigated after the structure was been repaired by composite overwrap. The objective of this study was the analysis of the efficiency of composite repair systems using this additional criterion to gain more confidence on it taking into account, the cracks and the overwrap geometries. The material of the pipe is elastic perfectly plastic for the plastic collapse pressure criterion and elastic-plastic using the Romberg Osgood model for fracture mechanic criterion. The additional criterion allows us to compare the uncracked and cracked pipe to estimate the repair efficiency. Moreover, the composite overwrap could restore 90% of the plastic collapse pressure for cracked pipes.

Engineering Structures, 2019

Journal of Materials Processing Technology, 2019

In this paper, we propose an analytical electromagnetic modelling and an electromechanical coupli... more In this paper, we propose an analytical electromagnetic modelling and an electromechanical coupling of the 1-turn bulk coil with a cut, made of conducting steel or copper alloys, and used in the electromagnetic forming technology. The electromagnetic part of the work is the one created beyond the state of the art. Such analytical models that can quickly solve for key process parameters are extremely desirable but must be completed with a mechanical model able to calculate in the end the deformation. An existing mechanical model to calculate the deformation is used and coupled to our electromagnetic model. First, the basic electromagnetic theory will be summarised and then the One-Dimensional (1-D) axi-symmetrical approximation discussed (part 2). The goal is to be able to determine the magnetic vector potential A diffusion, that will quickly lead to all the parameters needed to characterize, qualify, feed and optimize the use of the coil (ex.: magnetic flux density, equivalent inductance, force coefficients, …). Then the pseudoharmonic solution of the 1D-problem is expanded with the help of Bessel basis functions, including some specific limit conditions and constraints (part 3). The results are compared to numerical 2-D and 3-D computations, performed, thanks to the Finite Element Method, onto some test cases without and with a tube to deform. The proposed model does not only give the numerical value of each parameter, but it provides analytical formulae, with explicit dependences upon some key geometrical and physical variables (ex.: changeable air-gap between the coil and the tube linked to the deformation). The use of a pseudo harmonic working condition will be justified by comparing it to the transient working condition for which the model is improved. Experimental measurements will be carried out with and without a tube but with no deformation (part 4). The results are close and coherent and useful when sizing the coil with respect to performance criteria and performing an equivalent electrical circuit and an electro-mechanical coupling solution, usable with deformation in the transient working conditions (part 5).

Anti-Corrosion Methods and Materials, 2016

Purpose – The purpose of this paper was to find a simple and easy-operated method for filtering e... more Purpose – The purpose of this paper was to find a simple and easy-operated method for filtering eco-friendly corrosion inhibitors. Design/methodology/approach – The molecular structures and atomic electronegativities of the four kinds of natural reagents, iota-Carrageenan, sodium alginate, sodium dodecanesulphonate (SDS) and sodium dodecylbenzene sulfonate were calculated by Gaussian and Natural Bond Orbital, and the corrosion inhibition rates were forecasted by the calculated results. Then, the realistic corrosion inhibition efficiency were confirmed by electrochemical impedance spectroscopy and potentiodynamic polarization tests in 3.5 Wt.% sodium chloride corrosive solutions. At the same time, the function of pefloxacin mesylate (PM) was explored in this paper polarization tests in 3.5 Wt.% sodium chloride corrosive solutions. Findings – Results showed that the order calculated by the chemical software was correct, and the corrosion inhibition of SDS was the best. Optimum additio...

This paper presents a new method for static power factor correction (SPFC). A static system is us... more This paper presents a new method for static power factor correction (SPFC). A static system is used to compensate four-quadrant reactive power using only small component (capacitance) values. As such, SPFC is able to deal with inductive and/or capacitive load characteristics. The proposed SPFC method combines a passive filter and an inverter with pre-calculated pulse-width modulation (PWM) switching angles. The obtained system produces low harmonic distortion thus providing reliable and long lasting system components. Simulation results show that the system is able to provide variable positive and negative true and reactive powers while keeping the passive system components values constant.

2008 34th Annual Conference of IEEE Industrial Electronics, 2008

ABSTRACT This paper presents a new topology of three phases voltage with three levels inverter (N... more ABSTRACT This paper presents a new topology of three phases voltage with three levels inverter (NTTPTVLI) using precalculated voltage levels and switching angles. We have developed a computing model which calculates the voltage levels and the switching angles only in the one-sixth of period. Voltage levels and switching angles are deduced in the remaining five- sixth of period by symmetries. The voltage levels and the switching angles are precalculated so as to eliminate a maximum number of successive low ranked harmonics for a given fundamental magnitude voltage and a given number of switching per one-sixth period. This approach allows us to use, in the same time, a reduced number of switching per period and a small capacitance passive filter. Consequently, the total harmonics distortion (THD) in the output voltage, the power loses in the inverter are also reduced. Simulation results show a substantial reduction of the (THD) rate and the effectiveness of the proposed method.

31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005., 2005

... Kamal Meghriche 1 , Omar Mansouri 2 , Abderrezzak Cherifi 3 ... 37753779. [11] Werner H. Wöl... more ... Kamal Meghriche 1 , Omar Mansouri 2 , Abderrezzak Cherifi 3 ... 37753779. [11] Werner H. Wölfle, William G. Hurley, Quasi-active power factor correction with a variable inductive filter: theory, design and practice, IEEE Transactions on Power Electronics, vol. 18, no. ...