Hedi Sakli - Profile on Academia.edu (original) (raw)

Papers by Hedi Sakli

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Progress in Electromagnetics Research M, 2010

In microwaves, ferrites are characterized by a tensorial permeability which represents their anis... more In microwaves, ferrites are characterized by a tensorial permeability which represents their anisotropy under a constant magnetic field. We present, in this article, a rigorous study of the formulation of the transverse operator method (TOM) with an extension to the case of the guides of rectangular waves partially charged with longitudinally magnetized ferrite. We show the existence of the complex modes in these types of structures with ferrite. A good agreement of the constant of propagation with the literature is obtained.

Despite the vaccination campaigns in most countries in the world, we see horrible numbers of cont... more Despite the vaccination campaigns in most countries in the world, we see horrible numbers of contaminations and even deaths daily. According to the WHO, 181 521 067 confirmed cases including 3 937 437 deaths. As of 30 June 2021, a total of 2 915 585 482 vaccine doses have been administered. Although efforts to raise awareness of the severity of the corona virus, many people no longer respect the health protocol, which manifests through wearing a mask and respecting physical distancing. Research laboratories have spared no effort to find an effective vaccine. This will help minimize the effects of the virus and save the lives of those infected. On the other hand, COVID-19 patients admitted to hospitals ensure permanent control of their health conditions and intervene at the right time. Saving the lives of these is a necessity, and we are all cooperating to bring life back to its normal pattern before pandemic, which took a toll on countries' economies. This research focuses on the development of an intelligent system based on the IOT for remotely control the covid-19 patient from a monitoring unit. This solution will be very useful for treating patients during COVID-19 outbreak. It is a question of exchanging clinical information between medical staff thanks to new technologies and of putting the patient under permanent control. The virtualized treatment guarantees a healthy environment for personnel.

IEEE Access, 2021

This paper presents a method for designing a new two-element ultra-wideband (UWB) multiple-input-... more This paper presents a method for designing a new two-element ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna. We propose the design of an ultra-wideband antenna has been proposed with a study of its properties. An isolation technique using well-designed metamaterials is presented to achieve the miniaturization and performance of the two antennas and ensure proper operation of the MIMO system with a very small spacing between radiating elements (λ/12) where λ is the length waves in a vacuum. The metamaterials used considerably reduce the coupling of multi-antennas. The application of these materials called split-ring resonator (SRR) on the antenna patch plane has contributed to the increase in the performance of the antenna studied in terms of S parameters, multiplexing efficiency, diversity gain (DG), radiation properties and envelope correlation coefficient (ECC). This increases the transmission rate. This antenna system offers advantages such as reduction in weight and bulk, which facilitates its integration into a receiver, dedicated to 5G and connected objects.

In this chapter, we present an extension of the rigorous analysis of the propagation of electroma... more In this chapter, we present an extension of the rigorous analysis of the propagation of electromagnetic waves in magnetic transverse (TM) and transverse electric (TE) modes in a metallic circular waveguide partially filled with anisotropic metamaterial. In our analysis, the design of waveguide filters with uniaxial discontinuities is based on the determination of the higher-order modes, which have been analyzed and exploited. Below the cutoff frequency, the back backward waves can propagate in an anisotropic material. The numerical results with our MATLAB code for TM and TE modes were compared to theoretical predictions. Good agreements have been obtained. We analyzed a waveguide filters filled with partially anisotropic metamaterial using the mode matching (MM) technique based on the Scattering Matrix Approach (SMA), which, from the decomposition of the modal fields (TE and TM modes), are used to determine the dispersion matrix and thus the characterization of a discontinuity in waveguide. We extended the application of MM technique to the anisotropic material. By using modal analysis, our approach has considerably reduced the computation time compared to High Frequency Structure Simulator (HFSS) software.

Methodology for Quantifying Metamaterial Stored Energy Using Theory of Characteristic Mode

Metamaterials are artificial materials tailored to mold the flow of waves. Selecting a metamateri... more Metamaterials are artificial materials tailored to mold the flow of waves. Selecting a metamaterial for practical application is dependent on its effective parameter which classifies it as being electric or magnetic. This paper presents a theory of characteristic modes based quantitative approach for classifying metamaterial unit cell by means of stored energy. The presented results are promising for systematic design approaches for association of metamaterial unit cell to antennas such as in the design of metamaterial-inspired antennas.

Research Square (Research Square), May 23, 2023

Ultrasound imaging is commonly used to aid in fetal development. It has the advantage of being re... more Ultrasound imaging is commonly used to aid in fetal development. It has the advantage of being realtime, low-cost, non-invasive, and easy to use. However, fetal organ detection is a challenging task for obstetricians, it depends on several factors, such as the position of the fetus, the habitus of the mother, and the imaging technique. In addition, image interpretation must be performed by a trained healthcare professional who can take into account all relevant clinical factors. Arti cial intelligence is playing an increasingly important role in medical imaging and can help solve many of the challenges associated with fetal organ classi cation. In this paper, we propose a deep-learning model for automating fetal organ classi cation from ultrasound images. We trained and tested the model on a dataset of fetal ultrasound images, including two datasets from different regions, and recorded them with different machines to ensure the effective detection of fetal organs. We performed a training process on a labeled dataset with annotations for fetal organs such as the brain, abdomen, femur, and thorax, as well as the maternal cervical part. The model was trained to detect these organs from fetal ultrasound images using a deep convolutional neural network architecture. Following the training process, the model, DenseNet169, was assessed on a separate test dataset. The results were promising, with an accuracy of 99.84%, which is an impressive result. The F1 score was 99.84% and the AUC was 98.95%. Our study showed that the proposed model outperformed traditional methods that relied on the manual interpretation of ultrasound images by experienced clinicians. In addition, it also outperformed other deep learning-based methods that used different network architectures and training strategies. This study may contribute to the development of more accessible and effective maternal health services around the world and improve the health status of mothers and their newborns worldwide.

Electronics, Feb 17, 2021

This paper presents an extension of the formulation of wave propagation in transverse electric (T... more This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes for the case of metallic cylindrical waveguides filled with longitudinally magnetized ferrite. The higher order modes were exploited. We externally controlled the cut-off frequency through the application of DC magnetic fields. The numerical results of dispersion diagrams for TE and TM modes were obtained and analyzed. We analyzed a waveguide antenna filled with partially magnetized ferrite using the mode matching (MM) technique based on the TE and TM modes. By using modal analysis, our approach considerably reduced the computation time compared to HFSS. Ferrites are important for various industrial applications, such as circulators, isolators, antennas and filters.

Dispersion in the microwave planar dispositif with ferrite

In this paper, a rigorous study of the formulation of the transverse operator method (TOM) is des... more In this paper, a rigorous study of the formulation of the transverse operator method (TOM) is described for studying general propagating structures with transverse inhomogeneity and anisotropy. The dispersion characteristics of some multi-dielectric waveguide structures have been obtained. Other dielectric waveguides with arbitrary cross-sections can be studied by using this procedure with no modifications. The advantage of this method is that it has a fast convergence. The results are compared to those previously published and show a good agreement. The results presented here show that not only the transverse operator formulation is an elegant theoretical form, but it is also a powerful and efficient analysis method, it is useful to solve a number of the propagation problems in electromagnetics.

A new design of wideband microstrip antenna, where slots are placed on structure, is proposed. Al... more A new design of wideband microstrip antenna, where slots are placed on structure, is proposed. Also, a newly structure of a monopole antenna based on the noches form is designed using the HFSS. It has been found that the characteristics of new microstrip antenna are comparable to the conventional patch antennas, whereas its gain, directivity, and radiating efficiency are remarkably improved which make it to be useful in RFID chipless applications. The proposed antenna operates from 11.45 to 13.28 GHz, and 14.61 to 19.55 GHz can be used in RFID chipless applications, and it has a bandwidth about 677 MHz. The return loss of the proposed antenna is indeed below -10 dB. Prototype for all antennas are fabricated and measured and a good agreement between the measured and simulated results is achieved.

Propagation Constant of a Rectangular Waveguides Completely Full of Ferrite Magnetized Longitudinally

Journal of Infrared, Millimeter, and Terahertz Waves, May 5, 2009

ABSTRACT This paper is an analysis of rectangular waveguide completely full of ferrite magnetized... more ABSTRACT This paper is an analysis of rectangular waveguide completely full of ferrite magnetized longitudinally. The analysis is based on the formulation of the transverse operator method (TOM), followed by the application of the Galerkin method. We obtain an eigenvalue equation system. The propagation constant of some homogenous and anisotropic waveguide structures with ferrite has been obtained. The results presented here show that the transverse operator formulation is not only an elegant theoretical form, but also a powerful and efficient analysis method, it is useful to solve a number of the propagation problems in electromagnetic. One advantage of this method is that it presents a fast convergence. Numerical examples are given for different cases and compared with the published results. A good agreement is obtained.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2008

In hyper-frequencies, the ferrites are characterized by a tonsorial permeability which represents... more In hyper-frequencies, the ferrites are characterized by a tonsorial permeability which represents their inducted anisotropy under a magnetic field. This specific property makes the good formulation of the "Maxwell equation" harder. In this paper, a rigorous study of the formulation of the transverse operation method (TOM) is presented by a homogeneous rectangular structure of ferrites with transverse anisotropy which will be followed by the application of the Galerkin Method. Our study essentially focuses on the determination of the propagation constants and the electromagnetic fields in a rectangular wave-guide of ferrites magnetized longitudinally by a static magnetic field. Hence, we'll show the existence of complex modes in the ferrite structure.

Applied sciences, Mar 18, 2021

Thoracic radiography (chest X-ray) is an inexpensive but effective and widely used medical imagin... more Thoracic radiography (chest X-ray) is an inexpensive but effective and widely used medical imaging procedure. However, a lack of qualified radiologists severely limits the applicability of the technique. Even current Deep Learning-based approaches often require strong supervision, e.g., annotated bounding boxes, to train such systems, which is impossible to harvest on a large scale. In this work, we proposed the classification and prediction of lung pathologies of frontal thoracic X-rays using a modified model MobileNet V2. We considered using transfer learning with metadata leverage. We used the NIH Chest-Xray-14 database, and we did a comparison of performance of our approach to other state-of-the-art methods for pathology classification. The main comparison was by Area under the Receiver Operating Characteristic Curve (AUC) statistics and analyzed the differences between classifiers. Overall, we notice a considerable spread in the achieved result with an average AUC of 0.811 and an accuracy above 90%. We conclude that resampling the dataset gives a huge improvement to the model performance. In this work, we intended to create a model that is capable of being trained, and modified devices with low computing power because they can be implemented into smaller IoT devices.

In this paper, we propose a variant of the least squares boundary residual (LSBR) method which ta... more In this paper, we propose a variant of the least squares boundary residual (LSBR) method which takes into account the singularities of the electromagnetic field in the metal-dielectric edge due to the existence of the Gibbs phenomenon. A Systematic weight functions are employed in this method permitting to obtain accurate and efficient numerical results with an accelerated convergence. We present the extension of the modified LSBR method to the study of the dispersion of the planar structures partially full of ferrite longitudinally magnetized by a static magnetic field 0 H , containing conductors of negligible thickness in the interfaces. We modelise the strutures of the microstrip and finlines by a proposed general configuration.

Ferrite Image Lines Studies by Transverse Operator Method

HAL (Le Centre pour la Communication Scientifique Directe), 2009

In this paper, a rigorous study of the transverse operator method (TOM) formula- tion is presente... more In this paper, a rigorous study of the transverse operator method (TOM) formula- tion is presented by an inhomogeneous rectangular structure of ferrite with transverse anisotropy which will be followed by the application of the Galerkin method. Our study is essentially focused on the determination of the propagation constant in a ferrite image line magnetized longitudinally by a static magnetic fleld. The transverse operator method has been applied to a generalized multidielectric waveguide structure. Our results were obtained for the dielectric image line and compared with others approaches and good agreement with well kow analysis was obtained. 1. INTRODUCTION The formulation based on the study of the transverse components of the electric and magnetic flelds has been applied to dielectric waveguide problem by K. Ogusu (1). The TOM was developed and applied to a number of multidielectric waveguides (2,3). In this paper, the formulation of TOM will be presented for the ferrite image line. Our results are in good agreement with those previously published (4). The transverse operator which is another formulation of the Maxwell equations is here used to deflne the rectangular waveguide characteristics charged of ferrites. This method consists on eliminating the longitudinal components and resolving the propagation equation by developing the transverse flelds in series of modes of a closed structure (empty metal guide). The elimination of the longitudinal flelds in the Maxwell equations lets appear an operator L named the transverse operator. The resolution of the propagation equation by the Galerkin method leads to an eigenvalues equations. 2. THEORY At the microwaves frequencies, the ferrites are characterized by a tensorial permeability which rep- resents their induced anisotropy under a magnetic fleld. The permeability of the ferrite magnetised longitudinally is described by the Polder tensor:

Progress in Electromagnetics Research C, 2013

We hybridize vector Finite Element Method (FEM) and a Modified Multimodal Variational Formulation... more We hybridize vector Finite Element Method (FEM) and a Modified Multimodal Variational Formulation (MMVF) to the accurate and fast design of complex isotropic rectangular filters. The MMVF is applied to the full-wave description in the rectangular waveguides while the FEM characterizes waves in the arbitrarily shaped discontinuities. The proposed hybrid method is applied to the full-wave analysis of circuits with great practical interest (i.e., cross-shaped iris and multimode filters), thus improving CPU time and memory storage against several full-wave FEM based Computer Aided Design (CAD) tools (i.e., HFSS High Frequency Structural Simulator). The performances of the proposed hybrid method are validated with experimental results and HFSS simulations.

Sustainability

Road accidents occur everywhere in the world and the numbers of people dead or injured increase f... more Road accidents occur everywhere in the world and the numbers of people dead or injured increase from time to time. People hope that emergency vehicles and medical staff will arrive as soon as possible at the scene of the accident. The development of recent technologies such as the Internet of Things (IoT) allows us to find solutions to ensure rapid movement by road in emergencies. Integrating the healthcare sector and smart vehicles, IoT ensures this objective. This integration gives rise to two paradigms: the Internet of Vehicles (IoV) and the Internet of Medical Things (IoMT), where smart devices collect medical data from patients and transmit them to medical staff in real time. These data are extremely sensitive and must be managed securely. This paper proposes a system design that brings together the three concepts of Blockchain technology (BC), IoMT and IoV to address the problem mentioned above. The designed system is composed of three main parts: a list of hospitals, patient ...

Electronics

One of the most expensive and fatal natural disasters in the world is forest fires. For this reas... more One of the most expensive and fatal natural disasters in the world is forest fires. For this reason, early discovery of forest fires helps minimize mortality and harm to ecosystems and forest life. The present research enriches the body of knowledge by evaluating the effectiveness of an efficient wildfire and smoke detection solution implementing ensembles of multiple convolutional neural network architectures tackling two different computer vision tasks in a stage format. The proposed architecture combines the YOLO architecture with two weights with a voting ensemble CNN architecture. The pipeline works in two stages. If the CNN detects the existence of abnormality in the frame, then the YOLO architecture localizes the smoke or fire. The addressed tasks are classification and detection in the presented method. The obtained model’s weights achieve very decent results during training and testing. The classification model achieves a 0.95 F1-score, 0.99 accuracy, and 0.98e sensitivity....

A Rigorous Study of Some Planar Structures With Ferrite Magnetized Longitudinally by Modified LSBR Method

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2009

Electronics

A medical record is an important part of a patient’s follow-up. It comprises healthcare professio... more A medical record is an important part of a patient’s follow-up. It comprises healthcare professionals’ views, prescriptions, analyses, and all information about the patient. Several players, including the patient, the doctor, and the pharmacist, are involved in the process of sharing, and managing this file. Any authorized individual can access the electronic medical record (EMR) from anywhere, and the data are shared among various health service providers. Sharing the EMR requires various conditions, such as security and confidentiality. However, existing medical systems may be exposed to system failure and malicious intrusions, making it difficult to deliver dependable services. Additionally, the features of these systems represent a challenge for centralized access control methods. This paper presents SEMRAchain a system based on Access control (Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC)) and a smart contract approach. This fusion enables decentralize...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Progress in Electromagnetics Research M, 2010

In microwaves, ferrites are characterized by a tensorial permeability which represents their anis... more In microwaves, ferrites are characterized by a tensorial permeability which represents their anisotropy under a constant magnetic field. We present, in this article, a rigorous study of the formulation of the transverse operator method (TOM) with an extension to the case of the guides of rectangular waves partially charged with longitudinally magnetized ferrite. We show the existence of the complex modes in these types of structures with ferrite. A good agreement of the constant of propagation with the literature is obtained.

Despite the vaccination campaigns in most countries in the world, we see horrible numbers of cont... more Despite the vaccination campaigns in most countries in the world, we see horrible numbers of contaminations and even deaths daily. According to the WHO, 181 521 067 confirmed cases including 3 937 437 deaths. As of 30 June 2021, a total of 2 915 585 482 vaccine doses have been administered. Although efforts to raise awareness of the severity of the corona virus, many people no longer respect the health protocol, which manifests through wearing a mask and respecting physical distancing. Research laboratories have spared no effort to find an effective vaccine. This will help minimize the effects of the virus and save the lives of those infected. On the other hand, COVID-19 patients admitted to hospitals ensure permanent control of their health conditions and intervene at the right time. Saving the lives of these is a necessity, and we are all cooperating to bring life back to its normal pattern before pandemic, which took a toll on countries' economies. This research focuses on the development of an intelligent system based on the IOT for remotely control the covid-19 patient from a monitoring unit. This solution will be very useful for treating patients during COVID-19 outbreak. It is a question of exchanging clinical information between medical staff thanks to new technologies and of putting the patient under permanent control. The virtualized treatment guarantees a healthy environment for personnel.

IEEE Access, 2021

This paper presents a method for designing a new two-element ultra-wideband (UWB) multiple-input-... more This paper presents a method for designing a new two-element ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna. We propose the design of an ultra-wideband antenna has been proposed with a study of its properties. An isolation technique using well-designed metamaterials is presented to achieve the miniaturization and performance of the two antennas and ensure proper operation of the MIMO system with a very small spacing between radiating elements (λ/12) where λ is the length waves in a vacuum. The metamaterials used considerably reduce the coupling of multi-antennas. The application of these materials called split-ring resonator (SRR) on the antenna patch plane has contributed to the increase in the performance of the antenna studied in terms of S parameters, multiplexing efficiency, diversity gain (DG), radiation properties and envelope correlation coefficient (ECC). This increases the transmission rate. This antenna system offers advantages such as reduction in weight and bulk, which facilitates its integration into a receiver, dedicated to 5G and connected objects.

In this chapter, we present an extension of the rigorous analysis of the propagation of electroma... more In this chapter, we present an extension of the rigorous analysis of the propagation of electromagnetic waves in magnetic transverse (TM) and transverse electric (TE) modes in a metallic circular waveguide partially filled with anisotropic metamaterial. In our analysis, the design of waveguide filters with uniaxial discontinuities is based on the determination of the higher-order modes, which have been analyzed and exploited. Below the cutoff frequency, the back backward waves can propagate in an anisotropic material. The numerical results with our MATLAB code for TM and TE modes were compared to theoretical predictions. Good agreements have been obtained. We analyzed a waveguide filters filled with partially anisotropic metamaterial using the mode matching (MM) technique based on the Scattering Matrix Approach (SMA), which, from the decomposition of the modal fields (TE and TM modes), are used to determine the dispersion matrix and thus the characterization of a discontinuity in waveguide. We extended the application of MM technique to the anisotropic material. By using modal analysis, our approach has considerably reduced the computation time compared to High Frequency Structure Simulator (HFSS) software.

Methodology for Quantifying Metamaterial Stored Energy Using Theory of Characteristic Mode

Metamaterials are artificial materials tailored to mold the flow of waves. Selecting a metamateri... more Metamaterials are artificial materials tailored to mold the flow of waves. Selecting a metamaterial for practical application is dependent on its effective parameter which classifies it as being electric or magnetic. This paper presents a theory of characteristic modes based quantitative approach for classifying metamaterial unit cell by means of stored energy. The presented results are promising for systematic design approaches for association of metamaterial unit cell to antennas such as in the design of metamaterial-inspired antennas.

Research Square (Research Square), May 23, 2023

Ultrasound imaging is commonly used to aid in fetal development. It has the advantage of being re... more Ultrasound imaging is commonly used to aid in fetal development. It has the advantage of being realtime, low-cost, non-invasive, and easy to use. However, fetal organ detection is a challenging task for obstetricians, it depends on several factors, such as the position of the fetus, the habitus of the mother, and the imaging technique. In addition, image interpretation must be performed by a trained healthcare professional who can take into account all relevant clinical factors. Arti cial intelligence is playing an increasingly important role in medical imaging and can help solve many of the challenges associated with fetal organ classi cation. In this paper, we propose a deep-learning model for automating fetal organ classi cation from ultrasound images. We trained and tested the model on a dataset of fetal ultrasound images, including two datasets from different regions, and recorded them with different machines to ensure the effective detection of fetal organs. We performed a training process on a labeled dataset with annotations for fetal organs such as the brain, abdomen, femur, and thorax, as well as the maternal cervical part. The model was trained to detect these organs from fetal ultrasound images using a deep convolutional neural network architecture. Following the training process, the model, DenseNet169, was assessed on a separate test dataset. The results were promising, with an accuracy of 99.84%, which is an impressive result. The F1 score was 99.84% and the AUC was 98.95%. Our study showed that the proposed model outperformed traditional methods that relied on the manual interpretation of ultrasound images by experienced clinicians. In addition, it also outperformed other deep learning-based methods that used different network architectures and training strategies. This study may contribute to the development of more accessible and effective maternal health services around the world and improve the health status of mothers and their newborns worldwide.

Electronics, Feb 17, 2021

This paper presents an extension of the formulation of wave propagation in transverse electric (T... more This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes for the case of metallic cylindrical waveguides filled with longitudinally magnetized ferrite. The higher order modes were exploited. We externally controlled the cut-off frequency through the application of DC magnetic fields. The numerical results of dispersion diagrams for TE and TM modes were obtained and analyzed. We analyzed a waveguide antenna filled with partially magnetized ferrite using the mode matching (MM) technique based on the TE and TM modes. By using modal analysis, our approach considerably reduced the computation time compared to HFSS. Ferrites are important for various industrial applications, such as circulators, isolators, antennas and filters.

Dispersion in the microwave planar dispositif with ferrite

In this paper, a rigorous study of the formulation of the transverse operator method (TOM) is des... more In this paper, a rigorous study of the formulation of the transverse operator method (TOM) is described for studying general propagating structures with transverse inhomogeneity and anisotropy. The dispersion characteristics of some multi-dielectric waveguide structures have been obtained. Other dielectric waveguides with arbitrary cross-sections can be studied by using this procedure with no modifications. The advantage of this method is that it has a fast convergence. The results are compared to those previously published and show a good agreement. The results presented here show that not only the transverse operator formulation is an elegant theoretical form, but it is also a powerful and efficient analysis method, it is useful to solve a number of the propagation problems in electromagnetics.

A new design of wideband microstrip antenna, where slots are placed on structure, is proposed. Al... more A new design of wideband microstrip antenna, where slots are placed on structure, is proposed. Also, a newly structure of a monopole antenna based on the noches form is designed using the HFSS. It has been found that the characteristics of new microstrip antenna are comparable to the conventional patch antennas, whereas its gain, directivity, and radiating efficiency are remarkably improved which make it to be useful in RFID chipless applications. The proposed antenna operates from 11.45 to 13.28 GHz, and 14.61 to 19.55 GHz can be used in RFID chipless applications, and it has a bandwidth about 677 MHz. The return loss of the proposed antenna is indeed below -10 dB. Prototype for all antennas are fabricated and measured and a good agreement between the measured and simulated results is achieved.

Propagation Constant of a Rectangular Waveguides Completely Full of Ferrite Magnetized Longitudinally

Journal of Infrared, Millimeter, and Terahertz Waves, May 5, 2009

ABSTRACT This paper is an analysis of rectangular waveguide completely full of ferrite magnetized... more ABSTRACT This paper is an analysis of rectangular waveguide completely full of ferrite magnetized longitudinally. The analysis is based on the formulation of the transverse operator method (TOM), followed by the application of the Galerkin method. We obtain an eigenvalue equation system. The propagation constant of some homogenous and anisotropic waveguide structures with ferrite has been obtained. The results presented here show that the transverse operator formulation is not only an elegant theoretical form, but also a powerful and efficient analysis method, it is useful to solve a number of the propagation problems in electromagnetic. One advantage of this method is that it presents a fast convergence. Numerical examples are given for different cases and compared with the published results. A good agreement is obtained.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2008

In hyper-frequencies, the ferrites are characterized by a tonsorial permeability which represents... more In hyper-frequencies, the ferrites are characterized by a tonsorial permeability which represents their inducted anisotropy under a magnetic field. This specific property makes the good formulation of the "Maxwell equation" harder. In this paper, a rigorous study of the formulation of the transverse operation method (TOM) is presented by a homogeneous rectangular structure of ferrites with transverse anisotropy which will be followed by the application of the Galerkin Method. Our study essentially focuses on the determination of the propagation constants and the electromagnetic fields in a rectangular wave-guide of ferrites magnetized longitudinally by a static magnetic field. Hence, we'll show the existence of complex modes in the ferrite structure.

Applied sciences, Mar 18, 2021

Thoracic radiography (chest X-ray) is an inexpensive but effective and widely used medical imagin... more Thoracic radiography (chest X-ray) is an inexpensive but effective and widely used medical imaging procedure. However, a lack of qualified radiologists severely limits the applicability of the technique. Even current Deep Learning-based approaches often require strong supervision, e.g., annotated bounding boxes, to train such systems, which is impossible to harvest on a large scale. In this work, we proposed the classification and prediction of lung pathologies of frontal thoracic X-rays using a modified model MobileNet V2. We considered using transfer learning with metadata leverage. We used the NIH Chest-Xray-14 database, and we did a comparison of performance of our approach to other state-of-the-art methods for pathology classification. The main comparison was by Area under the Receiver Operating Characteristic Curve (AUC) statistics and analyzed the differences between classifiers. Overall, we notice a considerable spread in the achieved result with an average AUC of 0.811 and an accuracy above 90%. We conclude that resampling the dataset gives a huge improvement to the model performance. In this work, we intended to create a model that is capable of being trained, and modified devices with low computing power because they can be implemented into smaller IoT devices.

In this paper, we propose a variant of the least squares boundary residual (LSBR) method which ta... more In this paper, we propose a variant of the least squares boundary residual (LSBR) method which takes into account the singularities of the electromagnetic field in the metal-dielectric edge due to the existence of the Gibbs phenomenon. A Systematic weight functions are employed in this method permitting to obtain accurate and efficient numerical results with an accelerated convergence. We present the extension of the modified LSBR method to the study of the dispersion of the planar structures partially full of ferrite longitudinally magnetized by a static magnetic field 0 H , containing conductors of negligible thickness in the interfaces. We modelise the strutures of the microstrip and finlines by a proposed general configuration.

Ferrite Image Lines Studies by Transverse Operator Method

HAL (Le Centre pour la Communication Scientifique Directe), 2009

In this paper, a rigorous study of the transverse operator method (TOM) formula- tion is presente... more In this paper, a rigorous study of the transverse operator method (TOM) formula- tion is presented by an inhomogeneous rectangular structure of ferrite with transverse anisotropy which will be followed by the application of the Galerkin method. Our study is essentially focused on the determination of the propagation constant in a ferrite image line magnetized longitudinally by a static magnetic fleld. The transverse operator method has been applied to a generalized multidielectric waveguide structure. Our results were obtained for the dielectric image line and compared with others approaches and good agreement with well kow analysis was obtained. 1. INTRODUCTION The formulation based on the study of the transverse components of the electric and magnetic flelds has been applied to dielectric waveguide problem by K. Ogusu (1). The TOM was developed and applied to a number of multidielectric waveguides (2,3). In this paper, the formulation of TOM will be presented for the ferrite image line. Our results are in good agreement with those previously published (4). The transverse operator which is another formulation of the Maxwell equations is here used to deflne the rectangular waveguide characteristics charged of ferrites. This method consists on eliminating the longitudinal components and resolving the propagation equation by developing the transverse flelds in series of modes of a closed structure (empty metal guide). The elimination of the longitudinal flelds in the Maxwell equations lets appear an operator L named the transverse operator. The resolution of the propagation equation by the Galerkin method leads to an eigenvalues equations. 2. THEORY At the microwaves frequencies, the ferrites are characterized by a tensorial permeability which rep- resents their induced anisotropy under a magnetic fleld. The permeability of the ferrite magnetised longitudinally is described by the Polder tensor:

Progress in Electromagnetics Research C, 2013

We hybridize vector Finite Element Method (FEM) and a Modified Multimodal Variational Formulation... more We hybridize vector Finite Element Method (FEM) and a Modified Multimodal Variational Formulation (MMVF) to the accurate and fast design of complex isotropic rectangular filters. The MMVF is applied to the full-wave description in the rectangular waveguides while the FEM characterizes waves in the arbitrarily shaped discontinuities. The proposed hybrid method is applied to the full-wave analysis of circuits with great practical interest (i.e., cross-shaped iris and multimode filters), thus improving CPU time and memory storage against several full-wave FEM based Computer Aided Design (CAD) tools (i.e., HFSS High Frequency Structural Simulator). The performances of the proposed hybrid method are validated with experimental results and HFSS simulations.

Sustainability

Road accidents occur everywhere in the world and the numbers of people dead or injured increase f... more Road accidents occur everywhere in the world and the numbers of people dead or injured increase from time to time. People hope that emergency vehicles and medical staff will arrive as soon as possible at the scene of the accident. The development of recent technologies such as the Internet of Things (IoT) allows us to find solutions to ensure rapid movement by road in emergencies. Integrating the healthcare sector and smart vehicles, IoT ensures this objective. This integration gives rise to two paradigms: the Internet of Vehicles (IoV) and the Internet of Medical Things (IoMT), where smart devices collect medical data from patients and transmit them to medical staff in real time. These data are extremely sensitive and must be managed securely. This paper proposes a system design that brings together the three concepts of Blockchain technology (BC), IoMT and IoV to address the problem mentioned above. The designed system is composed of three main parts: a list of hospitals, patient ...

Electronics

One of the most expensive and fatal natural disasters in the world is forest fires. For this reas... more One of the most expensive and fatal natural disasters in the world is forest fires. For this reason, early discovery of forest fires helps minimize mortality and harm to ecosystems and forest life. The present research enriches the body of knowledge by evaluating the effectiveness of an efficient wildfire and smoke detection solution implementing ensembles of multiple convolutional neural network architectures tackling two different computer vision tasks in a stage format. The proposed architecture combines the YOLO architecture with two weights with a voting ensemble CNN architecture. The pipeline works in two stages. If the CNN detects the existence of abnormality in the frame, then the YOLO architecture localizes the smoke or fire. The addressed tasks are classification and detection in the presented method. The obtained model’s weights achieve very decent results during training and testing. The classification model achieves a 0.95 F1-score, 0.99 accuracy, and 0.98e sensitivity....

A Rigorous Study of Some Planar Structures With Ferrite Magnetized Longitudinally by Modified LSBR Method

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2009

Electronics

A medical record is an important part of a patient’s follow-up. It comprises healthcare professio... more A medical record is an important part of a patient’s follow-up. It comprises healthcare professionals’ views, prescriptions, analyses, and all information about the patient. Several players, including the patient, the doctor, and the pharmacist, are involved in the process of sharing, and managing this file. Any authorized individual can access the electronic medical record (EMR) from anywhere, and the data are shared among various health service providers. Sharing the EMR requires various conditions, such as security and confidentiality. However, existing medical systems may be exposed to system failure and malicious intrusions, making it difficult to deliver dependable services. Additionally, the features of these systems represent a challenge for centralized access control methods. This paper presents SEMRAchain a system based on Access control (Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC)) and a smart contract approach. This fusion enables decentralize...