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Electromechanical admittance-based automatic damage assessment in plate structures via one-dimensional CNN-based deep learning models

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Frontiers of Structural and Civil Engineering 2024年第11期18卷 1730-1751页

作者： thanh-Canh HUYNH Nhat-Duc HOANG Quang-Quang PHAM Gia Toai truong thanh-truong NGUYEN Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Faculty of Civil Engineering Duy Tan UniversityDa Nang 550000Vietnam Bridge and Road Department Danang Architecture UniversityDa Nang 550000Vietnam Faculty of Civil Engineering and Technology Dong A UniversityDa Nang 550000Vietnam Industrial Maintenance Training Center Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam

The conventional admittance approach utilizing statistical evaluation metrics offers limited information about the damage location,especially when damage introduces nonlinearities in admittance *** study proposes a novel automated damage localization method for plate-like structures based on deep learning of raw admittance signals.A one-dimensional(1D)convolutional neural network(CNN)-based model is designed to automate processing of raw admittance response and prediction of damage probabilities across multiple locations in a monitored *** admittance data set is augmented with white noise to simulate realistic measurement *** K-fold cross-validation technique is employed for training and testing the *** experimental validation of the proposed method shows that the proposed method can accurately identify the state and damage location in the plate with an average accuracy of 98%.Comparing with established 1D CNN models reveals superior performance of the proposed method,with significantly lower testing *** proposed method exhibits the ability to directly handle raw electromechanical admittance responses and extract optimal features,overcoming limitations associated with traditional piezoelectric admittance *** eliminating the need for signal preprocessing,this method holds promise for real-time damage monitoring of plate structures.

关键词： convolutional neural network electromechanical admittance electromechanical impedance piezoelectric transducer damage localization plate structure deep learning structural health monitoring

Development of an automatic and knowledge-infused framework for structural health monitoring based on prompt engineering

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Frontiers of Structural and Civil Engineering 2024年第11期18卷 1752-1774页

作者： truong-Thang NGUYEN Viet-Hung DANG thanh-Tung PHAM Faculty of Building and Industrial Construction Hanoi University of Civil EngineeringHanoi 11600Vietnam Research Group of Development and application of advanced materials and modern technologies in construction Hanoi University of Civil EngineeringHanoi 11600Vietnam

Collecting and analyzing vibration signals from structures under time-varying excitations is a non-destructive structural health monitoring approach that can provide meaningful information about the structures’safety without interrupting their normal *** paper develops a novel framework using prompt engineering for seamlessly integrating users’domain knowledge about vibration signals with the advanced inference ability of well-trained large language models(LLMs)to accurately identify the actual states of *** proposed framework involves formulating collected data into a standardized form,utilizing various prompts to gain useful insights into the dynamic characteristics of vibration signals,and implementing an in-house program with the help of LLMs to perform damage *** advantages,as well as limitations,of the proposed method are qualitatively and quantitatively assessed through two realistic case studies from literature,demonstrating that the present method is a new way to quickly construct practical and reliable structural health monitoring applications without requiring advanced programming/mathematical skills or obscure specialized programs.

关键词： structural health monitoring vibration large language model signal processing prompt engineering

ON BOUNDEDNESS PROPERTY OF SINGULAR INTEGRAL OPERATORS ASSOCIATED TO A SCHRODINGER OPERATOR IN A GENERALIZED MORREY SPACE AND APPLICATIONS

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Acta Mathematica Scientia 2020年第5期40卷 1171-1184页

作者： Xuan truong LE thanh Nhan NGUYEN Ngoc Trong NGUYEN Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Mathematics and Statistics Ton Due Thang UniversityHo Chi Minh CityVietnam Department of Mathematics Ho Chi Minh City University of EducationHo Chi Minh CityVietnam Department of Primary Education Ho Chi Minh City University of EducationHo Chi Minh CityVietnam

In this paper,we provide the boundedness property of the Riesz transforms associated to the Schrodinger operator■=-Δ+V in a new weighted Morrey space which is the generalized version of many previous Morrey type *** additional potential V considered in this paper is a non-negative function satisfying the suitable reverse Holder's *** results are new and general in many cases of *** an application of the boundedness property of these singular integral operators,we obtain some regularity results of solutions to Schrodinger equations in the new Morrey space.

关键词： weighted Morrey spaces Schodinger operator riesz transforms Regularity estima tes

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Atomistic simulation of free transverse vibration of graphene,hexagonal SiC, and BN nanosheets

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Acta Mechanica Sinica 2017年第1期33卷 132-147页

作者： Danh-truong Nguyen Minh-Quy Le thanh-Lam Bui Hai-Le Bui School of Mechanical Engineering Hanoi University of Science and Technology Hanoi 10000 Vietnam International Institute for Computational Science and Engineering Hanoi University of Science and TechnologyHanoi 10000 Vietnam Faculty of Mechanical Engineering Hanoi University of Industry Hanoi 10000 Vietnam

Free transverse vibration of monolayer graphene, boron nitride (BN), and silicon carbide (SiC) sheets is investigated by using molecular dynamics finite element method. Eigenfrequencies and eigenmodes of these three sheets in rectangular shape are studied with different aspect ratios with respect to various boundary conditions. It is found that aspect ratios and boundary conditions affect in a similar way on natural frequencies of graphene, BN, and SiC sheets. Natural frequencies in all modes decrease with an increase of the sheet’s size. Graphene exhibits the highest natural frequencies, and SiC sheet possesses the lowest ones. Missing atoms have minor effects on natural frequencies in this study.

关键词： Atomistic simulation Hexagonal sheet Transverse vibration Molecular dynamics finite element method

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Green Synthesis of Silver Nanoparticles Using Plectranthus Amboinicus Leaf Extract for Preparation of CMC/PVA Nanocomposite Film

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Journal of Renewable Materials 2021年第8期9卷 1393-1411页

作者： Nguyen Thi thanh Thuy Le Hoang Huy truong Thuy Vy Nguyen Thi thanh Tam Bien ThiLan thanh Nguyen Thi My Lan Nong Lam University Ho Chi Minh City Ho Chi Minh City700000Vietnam Industrial University of Ho Chi Minh City Ho Chi Minh City700000Vietnam University of Science Viet Nam National University Ho Chi Minh CityHo Chi Minh City700000Vietnam

In the present study,the biogenic silver nanoparticles have been synthesized using aqueous leaf extract of Plectranthus amboinicus(PA),which acted as both reducing and stabilizing *** PA synthesized silver nanoparticles were blended with carboxymethyl cellulose/polyvinyl alcohol(CMC/PVA)*** prepared AgNPs as well as the biogenic AgNPs incorporated CMC/PVA films were investigated using UV-visible spectrophotometry,Fourier-transform infrared spectroscopy(FT-IR),dynamic light scattering(DLS),scanning electron microscope(SEM),and X–ray diffraction(XRD).The DLS results showed that biogenic AgNPs had the average particle size of 65.70 nm with polydispersity index of *** surface plasmon resonance of AgNPs,which was determined by UV-vis spectrophotometry,showed the value of 410.00 *** results therefore confirmed the reduction Ag+into Ag°and the formation of AgNPs in the *** SEM imaging showed that AgNPs was quasi-spherical and *** XRD peaks at 33.07°,44.19°,64.58°and 77.47°confirmed the crystalline nature and presence of *** CMC/PVA films that incorporated with AgNPs displayed best mechanical strength and morphological properties than the pure CMC/PVA *** film of CMC/PVA-AgNPs exhibited significant antibacterial activities against Bacillus spizizenii,Staphylococcus aureus,Salmonella typhi and Escherichia Coli.

关键词： Carboxymethyl cellulose antibacterial green synthesis silver nanoparticles plectranthus amboinicus polyvinyl alcohol

A comparative study on kinetics and dynamics of two dump truck lifting mechanisms using MATLAB simscape

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 146-156页

作者： Thong Duc Hong Minh Quang Pham Son Cong Tran Lam Quang Tran truong thanh Nguyen Faculty of Transportation Engineering Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam Vietnam National University Ho Chi Minh City(VNU-HCM) Ho Chi Minh City 700000Vietnam Industrial Maintenance Training Center Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam

In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been *** mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding *** simulation findings are compared to the analytical calculation results in the steady state,and both methods show good *** the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model ***,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting *** established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system *** is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.

关键词： Dump truck Lifting mechanism Hydraulic MATLAB Simscape Kinetic dynamic analysis

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Adaptive Nonlinear PD Controller of Two-Wheeled Self-Balancing Robot with External Force

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Computers, Materials & Continua 2024年第11期81卷 2337-2356页

作者： Van-truong Nguyen Dai-Nhan Duong Dinh-Hieu Phan thanh-Lam Bui Xiem HoangVan Phan Xuan Tan Faculty of Mechatronics SMAEHanoi University of IndustryHanoi159999Vietnam Faculty of Electronics and Telecommunications Vietnam National University-University of Engineering and Technology(VNU-UET)Hanoi10000Vietnam College of Engineering Shibaura Institute of TechnologyTokyo135-8548Japan

This paper proposes an adaptive nonlinear proportional-derivative(ANPD)controller for a two-wheeled self-balancing robot(TWSB)modeled by the Lagrange equation with external *** proposed control scheme is designed based on the combination of a nonlinear proportional-derivative(NPD)controller and a genetic algorithm,in which the proportional-derivative(PD)parameters are updated online based on the tracking error and the preset error *** addition,the genetic algorithm is employed to adaptively select initial controller parameters,contributing to system stability and improved control *** proposed controller is basic in design yet simple to *** ANPD controller has the advantage of being computationally lightweight and providing high robustness against external *** stability of the closed-loop system is rigorously analyzed and verified using Lyapunov theory,providing theoretical assurance of its *** and experimental results show that the TWSB robot with the proposed ANPD controller achieves quick balance and tracks target values with very small errors,demonstrating the effectiveness and performance of the proposed *** proposed ANPD controller demonstrates significant improvements in balancing and tracking performance for two-wheeled self-balancing robots,which has great applicability in the field of robot control *** represents a promising solution for applications requiring precise and stable motion control under varying external conditions.

关键词： Two-wheeled self-balancing robot nonlinear PD control external force genetic algorithm

First Record of Sphenomorphus incognitus (Thompson, 1912) (Squamata: Scincidae) from Vietnam with Some Notes on Natural History

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Asian Herpetological Research 2012年第2期3卷 147-150页

作者： truong Quang NGUYEN Tung thanh TRAN Tao Thien NGUYEN Wolfgang BHME Thomas ZIEGLER Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology Present address: Department of Terrestrial Ecology Cologne Biocenter University of Cologne Vinh Phuc College of Education 4. Vietnam National Museum of Nature Vietnam Academy of Science and Technology 5. Zoologisches Forschungsmuseum Alexander Koenig 6. AG Zoologischer Garten Kln

Sphenomorphus incognitus is recorded for the first time outside of China. The new locality record is from the Tay Yen Tu Nature Reserve in Bac Giang Province, northeastern Vietnam at elevations between 200–450 m. Based on the newly collected specimens, we present an expanded description and provide data on the natural history of this species in northern Vietnam.

关键词： new record Sphenomorphus incognitus Tay Yen Tu Nature Reserve Bac Giang Province Vietnam

Prevalence and risk factors associated with long COVID symptoms in children and adolescents in a southern province of Vietnam

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Asian Pacific Journal of Tropical Medicine 2024年第3期17卷 119-128,I0001,I0002页

作者： Huynh Ngoc Linh Nguyen The Tan Le Thi Minh Thu Nguyen Tu Loan Nguyen Thi To Uyen Le thanh Thao Trang truong thanh Nam Doan Hoang Phu Faculty of Medicine Ca Mau Medical CollegeCa Mau 98000Vietnam Ca Mau Obstetrics and Pediatrics Hospital Ca Mau 98000Vietnam Faculty of Basic Science and Public Health Dong Thap Medical CollegeDong Thap 81000Vietnam Graduate University of Sciences and Technology Vietnam Academy of Science and TechnologyHa Noi 10000Vietnam Community Public Health Research Program School of Public HealthWalailak UniversityNakhon Si Thammarat 80160Thailand Faculty Public Health Can Tho University of Medicine and PharmacyCan Tho City 94000Vietnam Doctoral Program in Health Sciences College of Graduate StudiesWalailak UniversityNakhon Si Thammarat 80160Thailand

Objective:To investigate the prevalence and risk factors associated with long COVID symptoms among children and adolescents who have recovered from ***:This study applied a cross-sectional approach within community settings in a southern province of Vietnam.A structured questionnaire featuring socio-demographic information and common long COVID symptoms was *** correlation coefficients assessed associations among pairs of long COVID ***,multivariable logistic regression models were performed to investigate the risk factors of long COVID in recovered COVID-19 children and ***:Among 422 participants,39.3%reported long COVID symptoms,with a prevalence of 45.2%(SD=0.5)in children and 22.2%(SD=0.4)in *** symptoms reported were cough 34.6%(SD=0.5),fatigue 20.6%(SD=0.4),shortness of breath 10.9%(SD=0.3),and lack of appetite 6.6%(SD=0.3).Concerning risk factors of long COVID,a higher risk was observed among demographic groups,including girls(OR 1.25,95%CI 1.15-1.37;P<0.001,reference:boys),children compared to adolescents(OR 1.24,95%CI 1.12-1.37;P<0.001),overweight individuals(OR 1.14,95%CI 1.02-1.27;P=0.018,reference:healthy weight),and participants without any COVID-19 vaccination(OR 1.36,95%CI 1.20-1.54;P<0.001),or have received only one single dose(OR 1.35,95%CI 1.10-1.64;P=0.004)compared to those who have received two ***,patients with a COVID-19 treatment duration exceeding two weeks also had a higher risk of long COVID(OR 1.32,95%CI 1.09-1.60;P=0.003)than those who recovered less than seven ***:The insights from this study provide crucial guidance for predicting the factors associated with the occurrence of long COVID in pediatric patients,contributing to strategic interventions aimed at mitigating the long COVID risks among children and adolescents in Vietnam.

关键词： Long COVID Prevalence Risk factors Children Adolescent Vietnam