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A Cell-based Smoothed Finite Element Method for Modal Analysis of non-Woven Fabrics

Computers, Materials & Continua 2021年第6期67卷 2765-2795页

作者： nguyen T.Quyen n.Dourado A.J.P.Gomes F.b.n.Ferreira C2T—Centro de Ciência e Tecnologia Têxtil Departamento de Engenharia TêxtilUniversidade do MinhoCampus de AzurémGuimarães4804-533Portugal CMEMS-UMinho Departamento de Engenharia MecânicaUniversidade do MinhoCampus de AzurémGuimarães4804-533Portugal Department of Computer Science Universidade da Beira InteriorConvento de Sto.AntónioCovilhã6201-001Portugal Instituto de Telecomunicações R.Marquês deÁvila e BolamaCovilhã6201-001Portugal

The combination of a 4-node quadrilateral mixed interpolation of tensorial components element(MITC4)and the cell-based smoothed finite element method(CSFEM)was formulated and implemented in this work for the analysis of free vibration and unidirectional buckling of shell *** formulation was applied to numerous numerical examples of non-woven *** CSFEM schemes do not require coordinate transformation,spurious modes and numerical instabilities are prevented using bilinear quadrilateral element subdivided into two,three and four smoothing *** improvement of the original CSFEM formulation was made regarding the calculation of outward unit normal vectors,which allowed to remove the integral operator in the strain smoothing *** procedure conducted both to the simplification of the developed formulation and the reduction of computational cost.A wide range of values for the thickness-to-length ratio and edge boundary conditions were *** developed numerical model proved to overcome the shear locking phenomenon with success,revealing both reduced implementation effort and computational cost in comparison to the conventional FEM *** cell-based strain smoothing technique used in this work yields accurate results and generally attains higher convergence rate in energy at low computational cost.

关键词： Mindlin-Reissner theory of plates shear-locking gradient/strain smoothing technique non-woven fabric

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Positron Energy Levels in Cd-based Semiconductors

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Communications in Theoretical Physics 2013年第6期59卷 756-762页

作者： b.Abbar S.Mécabih S.Amari n.benosman b.bouhafs Laboratoire de Modélisation et de Simulation en Sciences des Département de Physique Université Djillali Liabès

Using the full potential linearized augmented plane wave FP-LAPW method within local density ap-proximation LDA, we have studied positron diffusion and surface emission in Cd-based semiconductors. This requires the calculation of electron and positron band structures. In the absence of experimental and theoretical data for CdX (X=S,Se,Te) we have treated the Si, which has been studied by several authors, as a test case. Predictive results on positron effective masses, deformation potentials, positron work functions, diffusion constants and positron mobilities are presented for CdX (X=S, Se, Te). Our calculated data for Si are compared with experimental and recent theoretical results.

关键词： DFT FP-LAPW semiconductors positron diffusion

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A Deep Convolutional Architectural Framework for Radiograph Image Processing at bit Plane Level for Gender&Age Assessment

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Computers, Materials & Continua 2020年第2期62卷 679-694页

作者： n.Shobha Rani M.Chandrajith b.R.Pushpa b.J.bipin nair Department of Computer Science Amrita School of Arts and SciencesMysuruAmrita Vishwa VidyapeethamIndia Maharaja Institute of Technology MysuruIndia

Assessing the age of an individual via bones serves as a fool proof method in true determination of individual *** attempts are reported in the past for assessment of chronological age of an individual based on variety of discriminative features found in wrist radiograph *** permutation and combination of these features realized satisfactory accuracies for a set of limited *** this paper,assessment of gender for individuals of chronological age between 1-17 years is performed using left hand wrist radiograph images.A fully automated approach is proposed for removal of noise persisted due to non-uniform illumination during the process of radiograph acquisition *** to this a computational technique for extraction of wrist region is proposed using operations on specific bit planes of image.A framework called Genet of deep convolutional neural network is applied for classification of extracted wrist regions into male and *** experimentations are conducted on the datasets of Radiological Society of north America(RSnA)of about 12442 *** of preprocessing and segmentation techniques resulted into a correlation of about 99.09%.Performance of Genet is evaluated on the extracted wrist regions resulting into an accuracy of 82.18%.

关键词： bit plane processing automated segmentation deep convolutional network

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Dynamics of SVEIS epidemic model with distinct incidence

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International Journal of biomathematics 2015年第6期8卷 99-117页

作者： n. nyamoradi M. Javidi b. Ahmad Department of Mathematics Faculty of Sciences Razi University 67149 Kermanshah Iran Faculty of Mathematical SciencesUniversity of Tabriz Tabriz Iran Department of Mathematics Faculty of Science King Abdulaziz University P. O. Box 80203 Yeddah 21589 Saudi Arabia

In this paper, we study the global dynamics of a SVEIS epidemic model with distinct incidence for exposed and infectives. The model is analyzed for stability and bifurcation behavior. To account for the realistic phenomenon of non-homogeneous mixing, the effect of diffusion on different population subclasses is considered. The diffusive model is analyzed using matrix stability theory and conditions for Turing bifurcation are derived. numerical simulations support our analytical results on the dynamic behavior of tile model.

关键词： SVEIS epidemic model diffusion Turing bifurcation stability basic repro-duction number numerical simulation.

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Micromechanical investigation of granular ratcheting using a discrete model of polygonal particles

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Particuology 2008年第6期6卷 390-403页

作者： Fernando Alonso-Marroquín Hans b. Mhlhaus Hans J. Herrmann Earth Systems Science Computational Centre & School of Physical Sciences The University of Queensland Earth Systems Science Computational Centre The University of Queensland Institut fr baustoffe ETH-HenggerbergZrich

We use a two-dimensional model of polygonal particles to investigate granular ratcheting. Ratcheting is a long-term response of granular materials under cyclic loading, where the same amount of permanent deformation is accumulated after each cycle. We report on ratcheting for low frequencies and extremely small loading amplitudes. The evolution of the sub-network of sliding contacts allows us to understand the micromechanics of ratcheting. We show that the contact network evolves almost periodically under cyclic loading as the sub-network of the sliding contacts reaches different stages of anisotropy in each cycle. Sliding contacts lead to a monotonic accumulation of permanent deformation per cycle in each particle. The distribution of these deformations appears to be correlated in form of vortices inside the granular assembly.

关键词： Granular systems Dynamics and kinematics of rigid bodies Molecular dynamics methods

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Atomistic material behavior at extreme pressures

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npj Computational Materials 2016年第1期2卷 93-96页

作者： Laurent Karim béland Yuri n Osetsky Roger E Stoller Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTNUSA

Computer simulations are routinely performed to model the response of materials to extreme environments,such as neutron(or ion)*** latter involves high-energy collisions from which a recoiling atom creates a so-called atomic displacement *** cascades involve coordinated motion of atoms in the form of supersonic *** shockwaves are characterized by local atomic pressures 415 GPa and interatomic distances o2Å.Similar pressures and interatomic distances are observed in other extreme environment,including short-pulse laser ablation,high-impact ballistic collisions and diamond anvil *** cascade simulations using four different force fields,with initial kinetic energies ranging from 1 to 40 keV,show that there is a direct relationship between these high-pressure states and stable defect *** important shortcoming in the modeling of interatomic interactions at these short distances,which in turn determines final defect production,is brought to light.

关键词： extreme defect latter

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numerical simulation of the effect of gold doping on the resistance to neutron irradiation of silicon diodes

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Journal of Semiconductors 2015年第1期36卷 47-51页

作者： K.bekhouche n.Sengouga b.K.Jones Laboratory of Metallic and Semiconducting Materials (LMSM) Université de Biskra 07000 Biskra Algeria Department of Physics Lancaster University Lancaster LA5 9LX UK

We have carried out a numerical simulation of the effect of gold doping on the electrical characteristics of long silicon diodes exposed to neutron irradiation. The aim is to investigate the effect of gold on the hardness of the irradiated diodes. The reverse current voltage and capacitance voltage characteristics of doped and undoped diodes are calculated for different irradiation doses. The leakage current and the effective doping density are extracted from these two characteristics respectively. The hardness of the diodes is evaluated from the evolution of the leakage current and the effective doping density with irradiation doses. It was found that diodes doped with gold are less sensitive to irradiation than undoped ones. Thus gold appears to stabilise the electrical properties on irradiation. The conduction mechanism is studied by the evolution of the current with temperature. The evaluated activation energy indicates that as the gold doping or irradiation dose increases, the current switches from the basic diffusion to the generation-recombination process, and that it can even become ohmic for very high gold densities or irradiation doses.

关键词： silicon diodes gold doping numerical simulation

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On Injectors of a Hartley Set of a Finite Group

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Algebra Colloquium 2018年第4期25卷 671-680页

作者： nanying Yang n.T.Vorob'ev T.b.Vasilevich School of Science Jiangnan UniversityWuxiJiangsu 214122China Department of Mathematics Masherov Vitebsk State University

Let G be a finite group andНbe a Hartley set of *** this paper,we prove the existence and conjugacy ofН-injectors of G and describe the characterization of injectors via *** applications,some known results are direc... 详细信息

关键词： Hartley set injector h-radical H-function

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Acoustic stop bands in almost-periodic and weakly randomized stratified media:perturbation analysis

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Acta Mechanica Sinica 2008年第5期24卷 549-556页

作者： S.Guenneau A.b.Movchan n.V.Movchan J.Trebicki Department of Mathematical Sciences University of LiverpoolPeach StreetLiverpool L69 3BXUK Polish Academy of Sciences Institute of Fundamental Technology ResearchSwietokrzyska 21Warsaw 00049Poland

In this paper, we analyze the effect of both deter- ministic and random perturbations of a regular multi-layered elastic structure on its stop band properties. The tool of choice is the transfer matrix method, which is both versatile and easy to implement. In both cases, we find that the stop-bands widen. We observe the appearance of very narrow pass-bands within the stop-bands, which can be observed in other instances in optics.

关键词： Transmission problem Small random perturbations Stop bands

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Structure of Some 4f Rare Earth Liquid Metals --A Charged Hard Sphere Approach

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Communications in Theoretical Physics 2006年第2X期46卷 337-342页

作者： P.b. Thakor P.n. Gajjar A.R. Jani Department of Physics Veer Nazmad South Gujarat University Udhana Magdalla Road Surat 395 007 Gujarat India Department of Physics Oujarat University Ahmedabd Oujarat India Department of Physics Sardar Patel University Vallabh Vidyanagar 388 120 Gujarat India

A well-established pseodopotential is used to study the structure of some 4f rare earth liquid metals （Ce, Pr, Eu, Gd, Tb, and Yb）. The structure factor S（q）, pair distribution function g（r）, interatomic distance r1, and coordination number n1 are calculated using Charged Hard Sphere （CHS） reference system. To introduce the exchange and correlation effects, the local field correction due to Sarkar et al. （S） is applied. The present investigation is successful in generating the structural information of Ce, Pr, Eu, Gd, Tb, and Yb 4f rare earth liquid metals.

关键词： pseudopotential structure factor pair distribution function interatomic distance

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