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A BOUNDARY INTEGRAL METHOD FOR COMPUTING ELASTIC MOMENT TENSORS FOR ELLIPSES AND ELLIPSOIDS

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Journal of Computational Mathematics 2007年第1期25卷 2-12页

作者： habib ammari HyeonbaeKang HyundaeLee Centre de Mathématiques Appliquées CNRS UMR 7641 and Ecole Polytechnique91128 Palaiseau CedexFrance Department of Mathematical Sciences and RIM Seoul National UniversitySeoul 151-747Korea

The concept of elastic moment tensor occurs in several interesting contexts, in particular in imaging small elastic inclusions and in asymptotic models of dilute elastic composites. In this paper, we compute the elastic moment tensors for ellipses and ellipsoids by using a systematic method based on layer potentials. Our computations reveal an underlying elegant relation between the elastic moment tensors and the single layer potential.

关键词： Elastic moment tensor Explicit formulae Integral equations.

SENSITIVITY ANALYSIS WITH RESPECT TO THE ELECTRICAL CONDUCTIVITY

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Journal of Computational Mathematics 2007年第3期25卷 244-251页

作者： habib ammari Cedex France Hyeonbae Kang Centre de Mathématiques Appliquées CNRS UMR 7641 and Ecole Polytechnique91128 Palaiseau School of Mathematical Sciences Seoul National UniversitySeoul 151-747Korea Habib Zribi Centre de Mathématiques AppliquéesCNRS UMR 7641 and Ecole Polytechnique91128 Palaiseau CedexFrance

In this paper, we consider conductivity inclusions inside a homogeneous background conductor. We provide a complete asymptotic expansion of the solution of such problems in terms of small variations in the electrical conductivity of the inclusion. Our method is based on a boundary integral perturbation theory. Our results are valid for both high and low contrast inclusions.

关键词： High contrast material Full-asymptotic expansions Boundary integral equa-tion.

SEPARATION OF SCALES IN ELASTICITY IMAGING:A NUMERICAL STUDY

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Journal of Computational Mathematics 2010年第3期28卷 354-370页

作者： habib ammari Pierre Garapon Franois Jouve Institut Langevin Laboratoire Ondes et Acoustique Laboratoire J.L.Lions Universite Paris Ⅶ Laboratoire J.L.Lions Université Paris Ⅶ

In magnetic resonance elastography, one seeks to reconstruct the shear modulus from measurements of the displacement field in the whole body. In this paper, we present an optimization approach which solves the problem by simply minimizing a discrepancy functional. In order to recover a complex anomaly in a homogenous medium, we first observe that the information contained in the wavefield should be decomposed into two parts, a ＂near-field＂ part in the region around the anomaly and a ＂far-field＂ part in the region away from the anomaly. As will be justified both theoretically and numerically, separating these scales provides a local and precise reconstruction.

关键词： Elastography multi-scale imaging anomaly reconstruction.

Approximate Boundary Conditions for Patch Antennas Mounted on Thin Dielectric Layers

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Communications in Computational Physics 2006年第6期1卷 1076-1095页

作者： habib ammari Hyeonbae Kang Eunjoo Kim Centre de Math´ematiques Appliqu´ees CNRS UMR 7641 and Ecole Polytechnique91128 Palaiseau CedexFrance Department of Mathematical Sciences and RIM Seoul National UniversitySeoul 151-747Korea

In this paper we discuss scattering problems inherent in curved microstrip structures mounted on thin dielectric *** provide approximate boundary conditions for such structures in the framework of integral equations.

关键词： Approximate boundary conditions boundary integral method thin dielectric layer patch antenna

Asymptotic Formulas for Thermography Based Recovery of Anomalies

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Numerical Mathematics(Theory,Methods and Applications) 2009年第1期2卷 18-42页

作者： habib ammari Anastasia Kozhemyak Darko Volkov Laboratoire Ondes et Acoustique CNRS UMR 7587ESPCI10 rue Vauquelin75231 Paris Cedex 05France. Centre de Mathématiques Appliquées CNRS UMR 7641Ecole Polytechnique91128 PalaiseauFrance. Department of Mathematical Sciences Worcester Polytechnic InstituteWorcester MA 01609USA.

We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design noniterative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.

关键词： Thermography imaging asymptotic formulas small anomalies direct imaging algorithms half-space problem.

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-Hun Jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance Industrial requirement

Pseudo-linear inertial navigation algorithm

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Chinese Journal of Aeronautics 2021年第2期34卷 191-200页

作者： habib GHANBARPOURASL Department of Mechcitronics University of Turkish Aeronautical AssociationAnkara 06790Turkey

A new method is illustrated for processing the output of a set of triad orthogonal rate gyros and accelerometers to reconstruct vehicle navigation parameters(attitude, velocity, and position). The paper introduces two vectors with dimensions 4×1 as velocity and position *** navigation equations for strapdown systems are nonlinear but after using these parameters, the navigation equations are converted into a pseudo-linear system. The new set of navigation equations has an analytical solution and the state transition matrix is used to solve the linear timevarying differential equations through time series. The navigation parameters are updated using the new formulation for strapdown navigation equations. Finally, the quaternions of velocity and position are converted into the original position and velocity vectors. The combination of the coning motion and a translational oscillatory trajectory is used to evaluate the accuracy of the proposed algorithm. The simulations show significant improvement in the accuracy of the inertial navigation system, which is achieved through the mentioned algorithm.

关键词： Inertial navigation algorithm Integrating algorithm Position quaternion Pseudo-linear inertial navigation equation Quaternions Velocity quaternion

Phylogenetic and morphometric relationships between two species of genus Auxis from the South China Sea and Java Sea

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Acta Oceanologica Sinica 2016年第10期35卷 76-82页

作者： habib Ahasan Environmental and Life Sciences Programme Faculty of ScienceUniversiti Brunei DarussalamJalan TungkuGadong BE 1410Brunei Darussalam Department of Fisheries and Marine Science Noakhali Science and Technology UniversitySonapur-3814NoakhaliBangladesh Universiti Teknologi Brunei Jalan TungkuGadong BE 1410Brunei Darussalam

This study was aimed at examining the phylogenetic and morphometric relationship of frigate tuna（Auxis thazard） and bullet tuna（Auxis rochei） using mt DNA D-loop（control） region sequences and truss measurements,respectively. Maximum-likelihood（ML） tree and median-joining network showed that haplotypes from Auxis populations grouped separately. Discriminant function analyses and non-metric multidimensional scaling of morphometric data showed that bullet and frigate tuna were differed mainly with respect to truss measurements on the anterior region, suggesting adaptation to different diets available in different environments. Historic demographic analyses of sequence data showed that both bullet and frigate tuna had not undergone a significant sudden population expansion recently. Non-significant value of Tajimas＇ s D and Fu＇s F_S were indicated an effective large and stable population size for longer period of both species in South China Sea and Java Sea species. This study gives first report on the complementary relationship between morphometric and genetic analysis in stock discrimination of genus Auxis.

关键词： phylogenetic relationship mtDNA D-loop morphometric analysis Auxis thazard Auxis rochei

Body Mass Index and Body Fat Percentage in Assessment of Obesity Prevalence in Saudi Adults

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Biomedical and Environmental Sciences 2013年第2期26卷 94-99页

作者： Syed Shahid habib Department of Physiology College of Medicine&King Khalid University HospitalKing Saud University

Objective To assess the obesity prevalence in body mass index （BMI） and body fat percentage Saudi adults according to the international standards of （BF%）. Methods Five hundred and thirty healthy Saudi adults aged 18-72 years （mean 36.91＋15.22 years） were enrolled in this study. Their body composition was assessed by bioelectrical impendence analysis with a commercially available body composition analyzer. Standard BMI and BF% values were used to define obesity. Results The prevalence of underweight, normal underweight, overweight and obesity in Saudi adults according to the BMI criteria （〈18.5 kg/mz, 18.5-24.4 kg/m2, 25-29.9 kg/m2, 30 k＆/m2 and above, respectively） was 2.5%, 30.2%, 33.6%, and 33.8%, respectively, whereas the obesity prevalence was 60% （n=31g） in Saudi adults according to the BF% criteria （25% for males and 30% for females）, which was significantly higher than that according to BMI criteria. However, it was 50.6% （n=268） when the BMI cutoff point was 27.5 kg/m2, proposed by WHO for the Asian population. Kappa analysis showed that the obesity prevalence defined by BMI and BF% was higher in females than in males （k=0.530 vs k=0.418, P〈O.O001）. The sensitivity and specificity of BMI （30 kg/m2 and 27.5 kg/m2） were 54.1% and 96.7% and 76.4% and 88.2%, respectively, for obesity. A lower BMI cutoff point （26.60 kg/m2） was proposed in this study, which gave the maximum sensitivity （84.3%） and specificity （85.4%）, with a moderate kappa agreement （k=0.686）. Moreover, the obesity prevalence at this cutoff point （56.4%） was significantly higher than that recommended by WHO. Conclusion The specificity of BMI for obesity is high and its sensitivity is low in both sexes. Its sensitivity can be increased by changing BMI cutoff to a lower value. The choice of BF% reference is of great influence for the assessment of obesity prevalence according to the BMI.

关键词： Body composition Obesity Body mass index Body fat percentage Kappa analysis