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Dynamic Modelling of a Hybrid Variable Reluctance Machine Using the 3D Finite Element method

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journal of Electromagnetic Analysis and Applications 2024年第7期16卷 103-113页

作者： Dingamadji Hilaire Belemdara jérôme Mbaïnaïbeye Department of Physics and Engineering Sciences University of NDjamena NDjamena Chad Department of Physics University of Moundou Moundou Chad

This paper presents the work carried out to evaluate the dynamic performance of the Hybrid Variable Reluctance Motor (HVRM). The fourth-order Runge-Kutta integration algorithm was employed to solve the equations of the dynamic model, in conjunction with the three-dimensional finite element method. The 3D numerical data was calculated using Comsol Multiphysics, which accounts for the nonlinearity of the ferromagnetic material and the 3D nature of the HVRM. The outcomes of this study are precise and accurately predict the dynamic behaviour of the HVRM in terms of rotor position response, rotational speed and torque. The distinctive contribution of this work lies in the 3D numerical modelling of the HVRM and the subsequent evaluation and analysis of its dynamic operation. Analytical and numerical 2D studies are less resource-intensive and time-consuming, and are more straightforward and rapid to analyse and interpret. However, they are constrained in their capacity to examine spatial, volumetric interactions and intricate dynamics such as flux studies where three 3D effects cannot be disregarded, winding end effects and the configuration and positioning of the interposed permanent magnet.

关键词： Numerical Computing Complex Dynamic Flux Linkage 3D Effects Equilibrium Position

Analysis of mid-spatial frequency wavefront distortions from a liquid-cooled flash-lamp pumped Nd:phosphate laser amplifier

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High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien G.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

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Intelligent Detection and Identification of Attacks in IoT Networks Based on the Combination of DNN and LSTM methods with a Set of Classifiers

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Open journal of Applied Sciences 2024年第8期14卷 2296-2319页

作者： Brou Médard Kouassi Vincent Monsan Kablan jérôme Adou Department of Mathematics and Computer Science University Felix Houphouet-Boigny Abidjan Cte dIvoire

Internet of Things (IoT) networks present unique cybersecurity challenges due to their distributed and heterogeneous nature. Our study explores the effectiveness of two types of deep learning models, long-term memory neural networks (LSTMs) and deep neural networks (DNNs), for detecting attacks in IoT networks. We evaluated the performance of six hybrid models combining LSTM or DNN feature extractors with classifiers such as Random Forest, k-Nearest Neighbors and XGBoost. The LSTM-RF and LSTM-XGBoost models showed lower accuracy variability in the face of different types of attack, indicating greater robustness. The LSTM-RF and LSTM-XGBoost models show variability in results, with accuracies between 58% and 99% for attack types, while LSTM-KNN has higher but more variable accuracies, between 72% and 99%. The DNN-RF and DNN-XGBoost models show lower variability in their results, with accuracies between 59% and 99%, while DNN-KNN has higher but more variable accuracies, between 71% and 99%. LSTM-based models are proving to be more effective for detecting attacks in IoT networks, particularly for sophisticated attacks. However, the final choice of model depends on the constraints of the application, taking into account a trade-off between accuracy and complexity.

关键词： Internet of Things Machine Learning Attack Detection jamming Deep Learning

Contribution to the Full 3D Finite Element Modelling of a Hybrid Stepping Motor with and without Current in the Coils

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journal of Electromagnetic Analysis and Applications 2024年第2期16卷 11-23页

作者： Belemdara Dingamadji Hilaire Mbaïnaïbeye jérôme Guidkaya Golam Department of Physics and Engineering Sciences University of N&#8217Djamena N&#8217Djamena Chad Department of Physics University of Moundou Moundou Chad Department of Physics University of Ngaoundere Ngaoundere Cameroon

The paper presents our contribution to the full 3D finite element modelling of a hybrid stepping motor using COMSOL Multiphysics software. This type of four-phase motor has a permanent magnet interposed between the two identical and coaxial half stators. The calculation of the field with or without current in the windings (respectively with or without permanent magnet) is done using a mixed formulation with strong coupling. In addition, the local high saturation of the ferromagnetic material and the radial and axial components of the magnetic flux are taken into account. The results obtained make it possible to clearly observe, as a function of the intensity of the bus current or the remanent induction, the saturation zones, the lines, the orientations and the magnetic flux densities. 3D finite element modelling provide more accurate numerical data on the magnetic field through multiphysics analysis. This analysis considers the actual operating conditions and leads to the design of an optimized machine structure, with or without current in the windings and/or permanent magnet.

关键词： Modelling 3D Finite Elements Magnetic Flux Hybrid Stepping Motor

Comparison of Two Recurrent Neural Networks for Rainfall-Runoff Modeling in the Zou River Basin at Atchérigbé (Bénin)

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journal of Geoscience and Environment Protection 2024年第9期12卷 167-181页

作者： Iboukoun Eliézer Biao Oscar Houessou Pierre jérôme Zohou Adéchina Eric Alamou National School of Mathematical Engineering and Modeling National University of Sciences Technology Engineering and Mathematics Abomey Benin LaGEA National School of Public Works National University of Sciences Technology Engineering and Mathematics Abomey Benin International Chair of Mathematical Physics and Applications (ICMPA-UNESCO Chair) University of Abomey-Calavi Abomey-Calavi Bnin

Hydrological models are developed to simulate river flows over a watershed for many practical applications in the field of water resource management. The present paper compares the performance of two recurrent neural networks for rainfall-runoff modeling in the Zou River basin at Atchérigbé outlet. To this end, we used daily precipitation data over the period 1988-2010 as input of the models, such as the Long Short-Term memory (LSTM) and Recurrent Gate Networks (GRU) to simulate river discharge in the study area. The investigated models give good results in calibration (R2 = 0.888, NSE = 0.886, and RMSE = 0.42 for LSTM;R2 = 0.9, NSE = 0.9 and RMSE = 0.397 for GRU) and in validation (R2 = 0.865, NSE = 0.851, and RMSE = 0.329 for LSTM;R2 = 0.9, NSE = 0.865 and RMSE = 0.301 for GRU). This good performance of LSTM and GRU models confirms the importance of models based on machine learning in modeling hydrological phenomena for better decision-making.

关键词： Supervised Learning Modeling Zou Basin Long and Short-Term memory Gated Recurrent Unit Hyperparameters Optimization

Unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neuropathology and behavioral deficits in parkinsonian rats withα-synucleinopathy

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Neural Regeneration Research 2024年第9期19卷 2057-2067页

作者： Bismark Gatica-Garcia Michael j.Bannon Irma Alicia Martínez-Dávila Luis O.Soto-Rojas David Reyes-Corona Lourdes Escobedo Minerva Maldonado-Berny me Gutierrez-Castillo Armando j.Espadas-Alvarez Manuel A.Fernandez-Parrilla juan U.Mascotte-Cruz CP Rodríguez-Oviedo Irais E.Valenzuela-Arzeta Claudia Luna-Herrera Francisco E.Lopez-Salas jaime Santoyo-Salazar Daniel Martinez-Fong Departamento de Fisiología Biofísica y NeurocienciasCentro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Department of Pharmacology Wayne State University School of MedicineDetroitMIUSA Laboratorio de Patogénesis Molecular Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico Red de medicina para la Educación y Desarrollo y la Investigación Científica de Iztacala(Red meDICI) Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico Nanoparticle Therapy Institute AguascalientesMéxico Departamento de Biociencias e Ingeniería Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y DesarrolloInstituto Politécnico NacionalCiudad de MéxicoMéxico Escuela Nacional de medicina y Homeopatía Instituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Fisiología Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Biología Molecular y Biotecnología Instituto de Investigaciones BiomédicasUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMéxico Departamento de Física Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Programa de Nanociencias y Nanotecnología Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico

Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-*** Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 *** study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced ***,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the *** addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia *** effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor *** results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor *** neurotrophic astrocytes and

关键词： A1 astrocytes A2 astrocytes gene therapy microglia motor deficits nanoparticles neurodegeneration neuroinflammation senescence α-synuclein aggregates

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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David j.Bottjer Department of Earth Sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Are hydrides under high-pressure-high-temperature superconductors?

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National Science Review 2024年第7期11卷 9-12页

作者： j.E.Hirsch Department of Physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides

Factors Associated with Overweight among Workers of the Ministry of Labor and Public Service in Benin in 2023

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Open journal of Internal medicine 2024年第3期14卷 299-318页

作者： Lucile T. S. Bedie Toïhen Géraud Padonou Charles jérôme Sossa Bayédjè Evrard Koutchoro Sègnon Eurydice Elvire Djossou Coovi Nonwanou Ignace Tokpanoude Badirou Aguemon Ministry of Labor and Public Service Cotonou Benin Faculty of Health Sciences (FSS) University of Abomey-Calavi (UAC) Cotonou Benin Health Promotion Department Regional Institute of Public Health Ouidah Benin

Introduction: The problem of excess weight is pandemic and affects the majority of nations, regardless of their level of development. However, the prevalence of overweight among workers in Benin is very poorly documented. To fill this gap, the present study aimed to determine the prevalence and factors associated with overweight among workers of the Ministry of Labor and Public Service (MTFP) in 2023 in Benin. Materials and methods: This is a descriptive cross-sectional study with analytical purposes carried out from August 16 to December 17, 2023, among MINISTRY OF LABOR AND PUBLIC SERVICE staff. The variables studied were overweight, sociodemographic, occupational and dietary characteristics, lifestyle, anthropometric factors and family history of obesity. An exhaustive recruitment of workers meeting our inclusion criteria and a questionnaire survey was carried out. Data were analyzed using R 4.0.4 software. A bivariate analysis followed by a multivariable analysis made it possible to identify the factors associated with overweight at the p Results: In total, 379 workers were included in our study. The average age of the surveyed workers was 44.86 years ± 7.67 years, with 202 (53.30%) workers at least 45 years old. men predominated with a number of 228 (60.16%). The prevalence of overweight was 63.32% (95% CI: [58.23 - 68.15]) and the associated factors after multivariate analysis were: female sex (ORa = 4.00;95% CI [2.11 - 7.76];p Conclusion: The prevalence of overweight is high among ministry of labor and public service workers. Education and awareness in the professional environment on the prevention and management of risk factors are essential for a long-term impact on a notable regression of this public health phenomenon.

关键词： Overweight Associated Factors Workers-Benin