43 research outputs found
A characterization of the essential pseudospectra and application to a transport equation
In this paper, we introduce and study the essential pseudospectra of closed, densely defined linear operators in the Banach space. We start by giving the definition and we investigate the characterization, the stability and some properties of this essential pseudospectra. The obtained results are used to describe the essential pseudospectra of transport operators.peerReviewe
Fredholm theory for demicompact linear relations
[EN] We first attempt to determine conditions on a linear relation T such
that ”T becomes a demicompact linear relation for each ” â [0, 1) (see
Theorems 2.4 and 2.5). Second, we display some results on Fredholm
and upper semi-Fredholm linear relations involving a demicompact one
(see Theorems 3.1 and 3.2). Finally, we provide some results in which
a block matrix of linear relations becomes a demicompact block matrix
of linear relations (see Theorems 4.2 and 4.3).Ammar, A.; Fakhfakh, S.; Jeribi, A. (2022). Fredholm theory for demicompact linear relations. Applied General Topology. 23(2):425-436. https://doi.org/10.4995/agt.2022.1694042543623
Modélisation et Optimisation d'un Générateur Synchrone à Double Excitation de Forte Puissance
Alliant flexibilité de contrÎle et bon rendement, les Machines Synchrone à Double Excitation (MSDE) sont de plus en plus investiguées pour diverses applications de petites et moyennes puissances et rarement pour des applications de fortes puissances. Cette thÚse a pour objectif l étude d un Générateur Synchrone à Double Excitation (GSDE) de forte puissance. Un modÚle de comportement a été établi. Des méthodes analytiques et semi-analytiques ont été utilisées pour la modélisation multi-physique de la machine. Ce modÚle a été validé, dans un premier temps, par comparaison aux résultats d un modÚle éléments finis.Comparé à un Générateur Synchrone à PÎles Saillants (GSPS), le GSDE offre des solutions plus intéressantes énergétiquement et économiquement, que ce soit en fonctionnement à vitesse constante ou à vitesse variable. Dans le cadre d un fonctionnement en générateur éolien, l augmentation du nombre d encoche par pÎle et par phase et l augmentation de la fréquence d alimentation contribuent à l amélioration des performances de la GSDE. Cependant il faudrait tenir compte des impacts sur l électronique de puissance et le multiplicateur mécanique. En plus, la distribution de Weibull et le bon choix de la plage utile de variation de la vitesse du vent, jouent un rÎle important sur le dimensionnement optimal du générateur éolien.Un prototype de GSDE d une puissance d 1MVA a été dimensionné, optimisé et fabriqué. Tout d abord, le prototype a servi à la validation du modÚle multi-physique. En plus la réalisation des essais sur deux étapes (avant et aprÚs le collage des aimants permanents) a montré l apport énergétique du GSDE par rapport au GSPSThe use of Hybrid Excitation Synchronous Machine (HESM) can widely be extended to any size of power applications in regards to its high efficiency and simplicity of flux control. The aim of this thesis consists to analyze different design constraints and develop optimization processes of a Hybrid Excitation Synchronous Generator (HESG).Analytical and lumped models were used with reasonable level of accuracy and minimum computation time. The model has been validated by comparing the result to those achieved by FEM.The study shows the technical and economical advantages of the use of HESG compare to the conventional Salient Pole Synchronous Generator (SPSG). The comparison between the two generator topologies was considered for constant and variable speed applications such as wind energy. The influence of several parameters such as frequency and the number of slot per pole and per phase was investigated. For the case of wind energy application the study shows the importance of Weibull distribution and the speed range when looking for the optimized generator.In order to validate the multi-physics model, a 1MVA HESG was considered and a prototype produced. To highlight the advantages and performances of HESG generator a test program was carried out into steps. A first set of tests have been made before bounding the permanent magnets and the second set of tests have been made after bounding the permanent magnetsVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF
ESSENTIALLY SEMI-REGULAR LINEAR RELATIONS
In this paper, we study the essentially semi-regular linear relation operators everywhere defined in Hilbert space. We establish a Kato-type decomposition of essentially semi-regular relations in Hilbert spaces. The result is then applied to study and give some properties of the Samuel-multiplicity
Modélisation et Optimisation d'un Générateur Synchrone à Double Excitation de Forte Puissance
Alliant flexibilité de contrÎle et bon rendement, les Machines Synchrone à Double Excitation (MSDE) sont de plus en plus investiguées pour diverses applications de petites et moyennes puissances et rarement pour des applications de fortes puissances. Cette thÚse a pour objectif l étude d un Générateur Synchrone à Double Excitation (GSDE) de forte puissance. Un modÚle de comportement a été établi. Des méthodes analytiques et semi-analytiques ont été utilisées pour la modélisation multi-physique de la machine. Ce modÚle a été validé, dans un premier temps, par comparaison aux résultats d un modÚle éléments finis.Comparé à un Générateur Synchrone à PÎles Saillants (GSPS), le GSDE offre des solutions plus intéressantes énergétiquement et économiquement, que ce soit en fonctionnement à vitesse constante ou à vitesse variable. Dans le cadre d un fonctionnement en générateur éolien, l augmentation du nombre d encoche par pÎle et par phase et l augmentation de la fréquence d alimentation contribuent à l amélioration des performances de la GSDE. Cependant il faudrait tenir compte des impacts sur l électronique de puissance et le multiplicateur mécanique. En plus, la distribution de Weibull et le bon choix de la plage utile de variation de la vitesse du vent, jouent un rÎle important sur le dimensionnement optimal du générateur éolien.Un prototype de GSDE d une puissance d 1MVA a été dimensionné, optimisé et fabriqué. Tout d abord, le prototype a servi à la validation du modÚle multi-physique. En plus la réalisation des essais sur deux étapes (avant et aprÚs le collage des aimants permanents) a montré l apport énergétique du GSDE par rapport au GSPSThe use of Hybrid Excitation Synchronous Machine (HESM) can widely be extended to any size of power applications in regards to its high efficiency and simplicity of flux control. The aim of this thesis consists to analyze different design constraints and develop optimization processes of a Hybrid Excitation Synchronous Generator (HESG).Analytical and lumped models were used with reasonable level of accuracy and minimum computation time. The model has been validated by comparing the result to those achieved by FEM.The study shows the technical and economical advantages of the use of HESG compare to the conventional Salient Pole Synchronous Generator (SPSG). The comparison between the two generator topologies was considered for constant and variable speed applications such as wind energy. The influence of several parameters such as frequency and the number of slot per pole and per phase was investigated. For the case of wind energy application the study shows the importance of Weibull distribution and the speed range when looking for the optimized generator.In order to validate the multi-physics model, a 1MVA HESG was considered and a prototype produced. To highlight the advantages and performances of HESG generator a test program was carried out into steps. A first set of tests have been made before bounding the permanent magnets and the second set of tests have been made after bounding the permanent magnetsVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF
The Essential Spectrum of a Sequence of Linear Operators in Banach Spaces
In this work we introduce some essential spectra of a sequence of closed linear operators on Banach space, we prove that if converges in the generalized sense to a closed linear operator , then there exists such that, for every , we have , where is a bounded linear operator, and . The same treatment is made when converges to zero compactly.</p
Interpretation of immunofluorescence slides by deep learning techniques: anti-nuclear antibodies case study
Nowadays, diseases are increasing in numbers and severity by the hour.
Immunity diseases, affecting 8\% of the world population in 2017 according to
the World Health Organization (WHO), is a field in medicine worth attention due
to the high rate of disease occurrence classified under this category. This
work presents an up-to-date review of state-of-the-art immune diseases
healthcare solutions. We focus on tackling the issue with modern solutions such
as Deep Learning to detect anomalies in the early stages hence providing health
practitioners with efficient tools. We rely on advanced deep learning
techniques such as Convolutional Neural Networks (CNN) to fulfill our objective
of providing an efficient tool while providing a proficient analysis of this
solution. The proposed solution was tested and evaluated by the immunology
department in the Principal Military Hospital of Instruction of Tunis, which
considered it a very helpful tool
Secret Technique To Hiding Image After Compression In Cover Image
This paper presents a technique for image compression and hiding in image of a high secret has been applied to wavelet transform and wavelet transform packet first apply two dimensional wavelet transform packet on the cover image was analysis and resorting to (Secret Sub bands level) of the cover image has secret algorithm either the image you want to hide has been compressed using two dimensional wavelet transform and then the application (Hard Thresholding) in order to reduce the values of the image and was also re-sorting to the transactions analysis (Secret Sub-band level) of the secret image(compressed image) Through a secret algorithm and then was minimized transaction values of sub bands level of image want to hide, the key used (random generated Key )to hide the secret, and this system has the property of the secret high in the process of concealment and the distribution of transactions analyzed for the image want to hide After the hit was so secret key and collected(adding) with the sub band level of the cover image on the adoption of the proposal are known algorithm with the secret key for both the sender and the receiver
Modeling and Optimization of a large Hybrid Excitation Synchronous Generator
Alliant flexibilitĂ© de contrĂŽle et bon rendement, les Machines Synchrone Ă Double Excitation (MSDE) sont de plus en plus investiguĂ©es pour diverses applications de petites et moyennes puissances et rarement pour des applications de fortes puissances. Cette thĂšse a pour objectif lâĂ©tude dâun GĂ©nĂ©rateur Synchrone Ă Double Excitation (GSDE) de forte puissance. Un modĂšle de comportement a Ă©tĂ© Ă©tabli. Des mĂ©thodes analytiques et semi-analytiques ont Ă©tĂ© utilisĂ©es pour la modĂ©lisation multi-physique de la machine. Ce modĂšle a Ă©tĂ© validĂ©, dans un premier temps, par comparaison aux rĂ©sultats dâun modĂšle Ă©lĂ©ments finis.ComparĂ© Ă un GĂ©nĂ©rateur Synchrone Ă PĂŽles Saillants (GSPS), le GSDE offre des solutions plus intĂ©ressantes Ă©nergĂ©tiquement et Ă©conomiquement, que ce soit en fonctionnement Ă vitesse constante ou Ă vitesse variable. Dans le cadre dâun fonctionnement en gĂ©nĂ©rateur Ă©olien, lâaugmentation du nombre dâencoche par pĂŽle et par phase et lâaugmentation de la frĂ©quence dâalimentation contribuent Ă lâamĂ©lioration des performances de la GSDE. Cependant il faudrait tenir compte des impacts sur lâĂ©lectronique de puissance et le multiplicateur mĂ©canique. En plus, la distribution de Weibull et le bon choix de la plage utile de variation de la vitesse du vent, jouent un rĂŽle important sur le dimensionnement optimal du gĂ©nĂ©rateur Ă©olien.Un prototype de GSDE dâune puissance dâ1MVA a Ă©tĂ© dimensionnĂ©, optimisĂ© et fabriquĂ©. Tout dâabord, le prototype a servi Ă la validation du modĂšle multi-physique. En plus la rĂ©alisation des essais sur deux Ă©tapes (avant et aprĂšs le collage des aimants permanents) a montrĂ© lâapport Ă©nergĂ©tique du GSDE par rapport au GSPSThe use of Hybrid Excitation Synchronous Machine (HESM) can widely be extended to any size of power applications in regards to its high efficiency and simplicity of flux control. The aim of this thesis consists to analyze different design constraints and develop optimization processes of a Hybrid Excitation Synchronous Generator (HESG).Analytical and lumped models were used with reasonable level of accuracy and minimum computation time. The model has been validated by comparing the result to those achieved by FEM.The study shows the technical and economical advantages of the use of HESG compare to the conventional Salient Pole Synchronous Generator (SPSG). The comparison between the two generator topologies was considered for constant and variable speed applications such as wind energy. The influence of several parameters such as frequency and the number of slot per pole and per phase was investigated. For the case of wind energy application the study shows the importance of Weibull distribution and the speed range when looking for the optimized generator.In order to validate the multi-physics model, a 1MVA HESG was considered and a prototype produced. To highlight the advantages and performances of HESG generator a test program was carried out into steps. A first set of tests have been made before bounding the permanent magnets and the second set of tests have been made after bounding the permanent magnet
Modélisation et Optimisation d'un Générateur Synchrone à Double Excitation de Forte Puissance
The use of Hybrid Excitation Synchronous Machine (HESM) can widely be extended to any size of power applications in regards to its high efficiency and simplicity of flux control. The aim of this thesis consists to analyze different design constraints and develop optimization processes of a Hybrid Excitation Synchronous Generator (HESG).Analytical and lumped models were used with reasonable level of accuracy and minimum computation time. The model has been validated by comparing the result to those achieved by FEM.The study shows the technical and economical advantages of the use of HESG compare to the conventional Salient Pole Synchronous Generator (SPSG). The comparison between the two generator topologies was considered for constant and variable speed applications such as wind energy. The influence of several parameters such as frequency and the number of slot per pole and per phase was investigated. For the case of wind energy application the study shows the importance of Weibull distribution and the speed range when looking for the optimized generator.In order to validate the multi-physics model, a 1MVA HESG was considered and a prototype produced. To highlight the advantages and performances of HESG generator a test program was carried out into steps. A first set of tests have been made before bounding the permanent magnets and the second set of tests have been made after bounding the permanent magnetsAlliant flexibilitĂ© de contrĂŽle et bon rendement, les Machines Synchrone Ă Double Excitation (MSDE) sont de plus en plus investiguĂ©es pour diverses applications de petites et moyennes puissances et rarement pour des applications de fortes puissances. Cette thĂšse a pour objectif lâĂ©tude dâun GĂ©nĂ©rateur Synchrone Ă Double Excitation (GSDE) de forte puissance. Un modĂšle de comportement a Ă©tĂ© Ă©tabli. Des mĂ©thodes analytiques et semi-analytiques ont Ă©tĂ© utilisĂ©es pour la modĂ©lisation multi-physique de la machine. Ce modĂšle a Ă©tĂ© validĂ©, dans un premier temps, par comparaison aux rĂ©sultats dâun modĂšle Ă©lĂ©ments finis.ComparĂ© Ă un GĂ©nĂ©rateur Synchrone Ă PĂŽles Saillants (GSPS), le GSDE offre des solutions plus intĂ©ressantes Ă©nergĂ©tiquement et Ă©conomiquement, que ce soit en fonctionnement Ă vitesse constante ou Ă vitesse variable. Dans le cadre dâun fonctionnement en gĂ©nĂ©rateur Ă©olien, lâaugmentation du nombre dâencoche par pĂŽle et par phase et lâaugmentation de la frĂ©quence dâalimentation contribuent Ă lâamĂ©lioration des performances de la GSDE. Cependant il faudrait tenir compte des impacts sur lâĂ©lectronique de puissance et le multiplicateur mĂ©canique. En plus, la distribution de Weibull et le bon choix de la plage utile de variation de la vitesse du vent, jouent un rĂŽle important sur le dimensionnement optimal du gĂ©nĂ©rateur Ă©olien.Un prototype de GSDE dâune puissance dâ1MVA a Ă©tĂ© dimensionnĂ©, optimisĂ© et fabriquĂ©. Tout dâabord, le prototype a servi Ă la validation du modĂšle multi-physique. En plus la rĂ©alisation des essais sur deux Ă©tapes (avant et aprĂšs le collage des aimants permanents) a montrĂ© lâapport Ă©nergĂ©tique du GSDE par rapport au GSP