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Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 180-196页

作者： H.C.Nguyen t.vo-minh Department of civil and environmental engineering imperial college londonuk Department of civil engineering and industrial design university of liverpoolliverpooluk Faculty of civil engineering ho chi minh city university of technology(hutech)ho chi minh cityviet nam

the node-based smoothed finite element method(NS-FEM)is shortly presented for calculations of the static and seismic bearing capacities of shallow strip footings.A series of computations has been performed to assess variations in seismic bearing capacity factors with both horizontal and vertical seismic *** results obtained agree very well with those using the slip-line method,revealing that the magnitude of the seismic bearing capacity is highly dependent upon the combinations of various directions of both components of the seismic *** upward vertical seismic acceleration reduces the seismic bearing capacity compared to the downward vertical seismic acceleration in *** addition,particular emphasis is placed on a separate estimation of the effects of soil and superstructure inertia on each seismic bearing capacity *** the effect of inertia forces arising in the soil on the seismic bearing capacity is non-trivial,and the superstructure inertia is the major contributor to reductions in the seismic bearing *** tables and charts are given for practical application to the seismic design of the foundations.

关键词： Limit analysis Node-based smoothed finite element method(NS-FEM) Second-order cone programming(SOCP) Seismic bearing capacity Strip footing

Bubble-enhanced quadrilateral finite element formulation for nonlinear analysis of geotechnical problems

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Underground Space 2018年第3期3卷 229-242页

作者： t.Vu-Hoang t.vo-minh H.Nguyen-Xuan Department of Civil Engineering HCMC University of TechnologyHo Chi Minh CityViet Nam Department of Civil Engineering Hutech UniversityHo Chi Minh CityViet Nam Center for Interdisciplinary Research in technology Hutech UniversityHo Chi Minh CityViet Nam

We investigate a new numerical procedure based on a bubble-enriched finite element formulation in combination with the implicit backward Euler scheme for nonlinear analysis of strip footings and stability of *** soil body is modeled as a perfect plastic Mohr-Coulomb *** displacement field is approximated by a 4-node quadrilateral element discretization enhanced with bubble *** loads and failure mechanisms in cohesive frictional soil are determined by solving a few Newton-Raphson *** results of the present approach are verified by both analytical solutions and other numerical solutions available in the literature.

关键词： Material nonlinear analysis Backward Euler scheme Bearing capacity Slope stability Bubble functions Finite elements

Free vibration analysis of laminated FG-CNt reinforced composite beams using finite element method

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Frontiers of Structural and Civil Engineering 2019年第2期13卷 324-336页

作者： t.vo-DUY V.HO-HUU t.NGUYEN-tHOI Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

In the present study, the free vibration of laminated functionally graded carbon nanotube reinforced composite beams is analyzed. the laminated beam is made of perfectly bonded carbon nanotubes reinforced composite (CNtRC) layers. In each layer, single-walled carbon nanotubes are assumed to be unifonnly distributed (UD) or functionally graded (FG) distributed along the thickness direction. Effective material properties of the two-phase composites, a mixture of carbon nanotubes (CNts) and an isotropic polymer, are calculated using the extended nile of mixture. the first-order shear deformation theory is used to formulate a governing equation for predicting free vibration of laminated functionally graded carbon nanotubes reinforced composite (FG?CNtRC) beams. the governing equation is solved by the finite element method with various boundary conditions. Several numerical tests are perfbnned to investigate the influence of the CNts volume fractions, CNts distributions, CNts orientation angles, boundary conditions, length-to-thickness ratios and the numbers of layers on the frequencies of the laminated FG-CNtRC beams. Moreover, a laminated composite beam combined by various distribution types of CNts is also studied.

关键词： free vibration analysis laminated FG-CNtRC beam finite element method first-order shear deformation theory composite material

Mental health around retirement:evidence of Ashenfelter’s dip

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Global Health Research and Policy 2023年第1期8卷 184-199页

作者： thang t.vo tran t.Phu-Duyen Health and Agricultural Policy Research Institute 279 Nguyen Tri PhuongDistrict 1072406 Ho Chi Minh CityVietnam School of Economics University of Economics HCMC279 Nguyen Tri PhuongDistrict 1072406 Ho Chi Minh CityVietnam

Background Mental health issues among retirees have become increasingly concerning because the aging population presents a significant challenge globally,particularly in Western *** studies on this issue are plagued with bias owing to lacking panel data and estimation *** study investigated the depression levels of European adults around the time of *** We used data obtained from Waves 1-7 of the Survey of Health,Ageing,and Retirement in Europe(SHARE)to create panel data covering the 2004-2017 *** 3(SHARELIFE)was excluded from the sample because it provided mismatched ***-effects(FE)and fixed-effects instrumental variables(FE-IV)models with multiple imputations were employed to examine the impacts of retirement on mental health before and after retirement,where being over pension age(normal and early)was used as the instrument *** Our results indicated that retirement based on aspirational motivations(β=−0.115,ptive circumstances(β=−0.038,ptly reduced depression,whereas retiring under negative circumstances could deteriorate one’s mental health(β=0.087,pted that overall,retiring reduced retirees’depression(β=−0.096,ptively).the results of FE-IV models showed that adults planning to retire in the next two years experienced less depression compared with others in the workforce(λ=−0.313,pthese adults must have adjusted their lifestyles in response to their impending retirement,thereby evincing Ashenfelter’s *** years after retirement,when the“honeymoon”phase was over,retirees may have completely adapted to their new lives and the effect of retirement was no longer *** Retirement improves mental health before it happens,but not *** the pension eligibility age may postpone the beneficial effects of retirement on ***,policy implications should be

关键词： Retirement Mental health Instrumental variable SHARE Panel data Ashenfelter’s dip

A combination of damage locating vector method （DLV） and differential evolution algorithm （DE） for structural damage assessment

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Frontiers of Structural and Civil Engineering 2018年第1期12卷 92-108页

作者： t. NGUYEN-tHOI A. tRAN-VIEt N. NGUYEN-minh t. vo-DUY V. HO-HUU Division of Computational Mathematics and Engineering Institute for Computational Science Ton Duc Thang University Hochiminh City Vietnam Division of Construction Computation Institute for Computational Science Ton Duc Thang University Hochiminh City Vietnam Faculty of Civil Engineering Ton Duc Thang University Hochiminh City Vietnam

In this study, a two-stage method is presented for identifying multiple damage scenarios. In the first stage, the damage locating vector （DLV） method using normalized cumulative energy （nce） is employed for damage localization in structures. In the second stage, the differential evolution algorithm （DE） is used for damage severity of the structures. In addition, in the second stage, a modification of an available objective function is made for handing the issue of symmetric structures. to verify the effectiveness of the present technique, numerical examples of a 72-bar space truss and a one-span steel portal frame are considered. In addition, the effect of noise on the performance of the identification results is also investigated. the numerical results show that the proposed combination gives good assessment of damage location and extent for multiple structural damage cases.

关键词： damage assessment damage locating vector method (DLV) differential evolution (DE) multiple damagelocation assurance criterion (MDLAC) mode shape error function

Damage assessment of laminated composite beam structures using damage locating vector （DLV） method

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Frontiers of Structural and Civil Engineering 2015年第4期9卷 457-465页

作者： t. vo-DUY Division of Computational Mathematics and Engineering (CME) Institute for Computational Science (INCOS) Ton Duc ThangUniversity Hochiminh City Vietnam Division of Construction Computation (DCC) Institute for Computational Science (INCOS) Ton Duc Thang University HochiminhCity vietnam Faculty of Civil Engineering Ton Duc Thang University Hochiminh City Vietnam

In this paper, the damage locating vector (DLV) method using normalized cumulative energy (nce) is employed to locate multiple damage sites in laminated composite beam structures. Numerical simulations of two laminated composite beams are employed to investigate several damage scenarios in which the degradation of elements is modeled by the reduction in the longitudinal Young’s modulus and transverse Young’s modulus of beam layers. the results show that the DLV method gives good performance for this kind of structure.

关键词： damage locating vector method (DLV) laminated composite beam structure normalized cumulative energy structural health monitoring (SHM)

A Cyborg Insect Reveals a Function of a Muscle in Free Flight

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Cyborg and Bionic Systems 2022年第1期2022卷 98-108页

作者： t.thang vo-Doan V.than Dung Hirotaka Sato Nanyang technological University School of Mechanical and Aerospace EngineeringSingapore University of Freiburg Institute of Biology I Germany

While engineers put lots of effort,resources,and time in building insect scale micro aerial vehicles(MAVs)that fly like insects,insects themselves are the real masters of *** if we would use living insect as platform for MAV instead?Here,we reported a flight control via electrical stimulation of a flight musde of an insect-computer hybrid robot,which is the interface of a mountable wireless backpack controller and a living *** beetle uses indirect flight muscles to drive wing flapping and three major direct flight muscles(basalar,subalar,and third axilliary(3Ax)muscles)to control the kinematics of the wings for flight *** turning control was already achieved by stimulating basalar and 3Ax muscles,electrical stimu lation of subalar musdes resulted in braking and elevation control in *** also demonstrated around 20 degrees of contralateral yaw and roll by stimulating individual subalar *** both subalar muscles lead to an increase of 20 degrees in pitch and decelerate the flight by 1.5 m/s2 as well as an induce in elevation of 2m/s.

关键词： robot computer mount

Enhanced Intrusion Detection System for an EH Iot Architecture Using a Cooperative UAV Relay and Friendly UAV Jammer

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IEEE/CAA Journal of Automatica Sinica 2021年第11期8卷 1786-1799页

作者： Van Nhan vo Hung tran Chakchai So-In Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Faculty of Information technology Duy Tan UniversityDa Nang 550000Vietnam Applied Network technology Laboratory Department of Computer ScienceFaculty of ScienceKhon Kaen UniversityKhon Kaen 40002Thailand Faculty of Computer Science Phenikaa UniversityHanoi 100000Vietnam

In this paper,the detection capabilities and system performance of an energy harvesting(EH)Internet of things(Io t)architecture in the presence of an unmanned aerial vehicle(UAV)eavesdropper(UE)are *** communication protocol is divided into two *** the first phase,a UAV relay(UR)cooperates with a friendly UAV jammer(UJ)to detect the UE,and the UR and UJ harvest energy from a power beacon(PB).In the second phase,a ground base station(GBS)sends a confidential signal to the UR using non-orthogonal multiple access(NOMA);the UR then uses its harvested energy to forward this confidential signal to Iot destinations(IDs)using the decode-and-forward(DF)***,the UJ uses its harvested energy to emit an artificial signal to combat the detected UE.A closed-form expression for the probability of detecting the UE(the detection probability,DP)is derived to analyze the detection ***,the intercept probability(IP)and throughput of the considered Iot architecture are ***,we identify the optimal altitudes for the UR and UJ to enhance the system and secrecy *** Carlo simulations are employed to verify our approach.

关键词： Detection probability(DP) energy harvesting(EH) friendly UAV jammer Internet of things(Iot) system performance UAV detection

Radiative decays D*(s)→ D(s)γ in covariant confined quark model

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Chinese Physics C 2024年第2期48卷 45-56页

作者： C.t.tran M.A.Ivanov P.Santorelli Q.C.vo Department of Physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of theoretical Physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.Pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢ*** radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by *** compare our results with other theoretical studies and experimental *** couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).the most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.

关键词： covariant quark model radiative decay charmed meson

Monitoring and modeling of urban sprawl through remote sensing and GIS in Kuala Lumpur, Malaysia

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Ecological Processes 2015年第1期4卷 165-174页

作者： Mukesh Singh Boori Maik Netzband Komal Choudhary Vít.voženílek Palacky University Olomouc 17.listopadu 5077146 OlomoucCzech Republic Geographical Institute Ruhr University BochumBochumGermany Samara State Aerospace University SamaraRussia

Introduction:Kuala Lumpur is currently experiencing a large-scale urban *** study explores a multi-buffer ring method to investigate the spatial and temporal dynamics of urban growth in the Kuala Lumpur metropolitan area by using Geographical Information Systems(GIS)and remote sensing imageries from1989 to ***:the first Landsat images from 1989,2001,and 2014 were classified with maximum likelihood classification to produce land cover maps and identify four types of land cover:urban/built-up,agriculture,forest,and ***,the area coverage for all the land use types at different points in time were measured and combined with distance from the city *** on,urbanization densities from the city center to the outside for every 1-km distance from 1 to 50 km are ***:City density on the distance of 5,8,15,20,and 30 km was very high in the years 1989 and ***,urban expansion shows fast and slow growth stages with high-speed growth shifting to the east side of the ***:In general,the population,traffic conditions,industrialization,and policy are the major factors thatinfluenced the urban expansion.

关键词： Urbanization Landsat Change detection Remote Sensing GIS