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Structural Characteristics of Allomyrina Dichotoma Beetle＇s Hind Wings for Flapping Wing Micro Air Vehicle

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Journal of Bionic Engineering 2014年第2期11卷 226-235页

作者： Ngoc San Ha quang Tri truong Hoang Vu Phan Nam Seo Goo Hoon Cheol Park Biomimetics and Intelligent Microsystem Laboratory Department of Advanced Technology Fusion Division of Interdisciplinary Studies Konkuk University Seoul 143-701 Republic of Korea

In this study, we present a complete structural analysis ofAllomyrina dichotoma beetle＇s hind wings by investigating their static and dynamic characteristics. The wing was subjected to the static loading to determine its overall flexural stiffness. Dy- namic characteristics such as natural frequency, mode shape, and damping ratio of vibration modes in the operating frequency range were determined using a Bruel ＆ Kjaer fast Fourier transform analyzer along with a laser sensor. The static and dynamic characteristics of natural Allomyrina dichotoma beetle＇s hind wings were compared to those of a fabricated artificial wing. The results indicate that natural frequencies of the natural wing were significantly correlated to the wing surface area density that was defined as the wing mass divided by the hind wing surface area. Moreover, the bending behaviors of the natural wing and artificial wing were similar to that of a cantilever beam. Furthermore, the flexural stiffness of the artificial wing was a little higher than that of the natural one whereas the natural frequency of the natural wing was close to that of the artificial wing. These results provide important information for the biomimetic design of insect-scale artificial wings, with which highly ma- neuverable and efficient micro air vehicles can be designed.

关键词： beetle hind wing flexural stiffness natural frequency mode shape Micro Air Vehicles (MAVs)

A novel approach for synthesis of hierarchical mesoporous Nd2O3 nanomaterials

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Journal of Rare Earths 2017年第7期35卷 677-682页

作者： Le Huu Trinh Dinh quang Khieu Hoang Thai Long Tran Thai Hoa Duong Tuan quang nguyen Duc Cuong College of Sciences Hue University 77 Nguyen Hue Hue City Viet Nam Faculty of Hospitality and Tourism Hue University 22 Lam Hoang Hue CityViet Nam College of Education Hue University 34 Le LoL Hue City Viet Nam

A novel route to the fabrication of hierarchical mesoporous Nd_2O_3 nanostructures including nanospheres and nanoporous network was described. Their structure and morphology evolution of the as-synthesized materials were determined by various techniques such as scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transforminfrared spectra, nitrogen adsorption/desorption isotherm, and a formation mechanism was proposed. The results revealed that the Nd_2O_3 nanospheres had the diameter of 300 nm, which were composed of small primary nanoparticles（NPs） with the size of 10 nm. The nanoporous structure also formed the NPs of ca. 10 nm which were connected with each other to form a three-dimensional（3D） texture. This simple and mild approach to fabricate hierarchical mesoporous Nd_2O_3 nanostructures could be easily scaled up and potentially extended to synthesize other oxide hierarchical structures.

关键词： Nd2O3 hierarchical nanostructures nanospheres nanoporous network rare earths

Taxonomic notes of three tea-plants(Camellia ***)recently described in Vietnam

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Beverage Plant Research 2022年第1期2卷 174-176页

作者： nguyen Trung Thanh Luong Van Dung Le Nguyet Hai Ninh quang Cuong truong Shixiong Yang Faculty of Biology VNU University of Science334 Nguyen TraiHanoi 100000Vietnam Faculty of Biology Dalat UniversityPhu Dong ThienVuong str.01Dalat66106Lam DongVietnam Faculty of Nong Lam Hoa Lu UniversityNinh Binh 40000Vietnam Bidoup Nui Ba National Park Tran Hung Dao str.5EDalat66116Lam DongVietnam CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina

Camellia sinensis *** is a heterotypic synonym of *** *** flosculora and *** were excluded from ***.

关键词： notes Vietnam Camellia

A Novel Method in Wood Identification Based on Anatomical Image Using Hybrid Model

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Computer Systems Science & Engineering 2023年第11期47卷 2381-2396页

作者： nguyen Minh Trieu nguyen truong Thinh College of Technology and Design University of Economics Ho Chi Minh City—UEHHo Chi Minh City72516Vietnam

Nowadays,wood identification is made by experts using hand lenses,wood atlases,and field manuals which take a lot of cost and time for the training *** quantity and species must be strictly set up,and accurate identification of the wood species must be made during exploitation to monitor trade and enforce regulations to stop illegal *** the development of science,wood identification should be supported with technology to enhance the perception of fairness of *** automatic wood identification system and a dataset of 50 commercial wood species from Asia are established,namely,wood anatomical images collected and used to train for the proposed *** the convolutional neural network(CNN),the last layers are usually soft-max functions with dense *** layers contain the most parameters that affect the speed *** reduce the number of parameters in the last layers of the CNN model and enhance the accuracy,the structure of the model should be optimized and ***,a hybrid of convolutional neural network and random forest model(CNN-RF model)is introduced to wood *** accuracy’s hybrid model is more than 98%,and the processing speed is 3 times higher than the CNN *** highest accuracy is 1.00 in some species,and the lowest is *** results show the excellent adaptability of the hybrid model in wood identification based on anatomical *** also facilitates further investigations of wood cells and has implications for wood science.

关键词： Identifying wood anatomical wood hybrid model CNN-RF automatic identification vietnam wood

Assessment of early-age cracking of high-performance concrete in restrained ring specimens

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Water Science and Engineering 2010年第1期3卷 113-120页

作者： quang-phu nguyen Lin-hua JIANG Qiao ZHU College of Mechanics and Materials Hohai University Nanjing 210098 P R. China Faculty of Civil Engineering Water Resources University Hanoi Vietnam

High-performance concrete （HPC） is stronger and more durable than conventional concrete. However, shrinkage and shrinkage cracking are common phenomena in HPC, especially early-age cracking. This study assessed early-age cracking of HPC for two mixtures using restrained ring tests. The two mixtures were produced with water/binder mass ratio （mw/mB） of 0.22 and 0.40, respectively. The results show that, with greater steel thickness, the higher degree of restraint resulted in a higher interface pressure and earlier cracking. With steel thickness of 6 mm, 19 mm, and 30 mm, the age of cracking were, respectively, 12 days, 8 days, and 5.4 days with the mw/mB = 0.22 mixture; and 22.5 days, 12.6 days, and 7.1 days with the mw/mB= 0.40 mixture. Cases of the same steel thickness show that the ring specimens with a thicker concrete wall crack later. With the mw/mB = 0.22 mixture, concrete walls with thicknesses of 37.5 mm, 75 mm, and 112.5 mm cracked at 3.4 days, 8.0 days, and 9.8 days, respectively; with the mw/mB = 0.40 mixture, the ages of cracking were 7.1 days, 12.6 days, and 16.0 days, respectively.

关键词： high-performance concrete shrinkage early-age cracking restrained ring test

Optimization of buckling load for laminated composite plates using adaptive Kriging-improved PSO:A novel hybrid intelligent method

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Defence Technology（防务技术） 2021年第1期17卷 85-99页

作者： Behrooz Keshtegar Trung nguyen-Thoi Tam T.truong Shun-Peng Zhu School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu611731China Department of Civil Engineering Faculty of EngineeringUniversity of ZabolP.B.***ZabolIran Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam

An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial *** this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization *** active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex *** cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data *** buckling load of the LCPs is maximized by utilizing the IPSO *** demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are *** results obtained by proposed method are in good agreement with the literature results,but with less computational *** applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.

关键词： Adaptive kriging Laminated composite plates Buckling optimization Smooth finite element methods Cell-based smoothed discrete shear gap method(CS-DSG3) Improved PSO

An Enhanced Ensemble-Based Long Short-Term Memory Approach for Traffic Volume Prediction

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Computers, Materials & Continua 2024年第3期78卷 3585-3602页

作者： Duy quang Tran Huy Q.Tran Minh Van nguyen Faculty of Civil Engineering Nha Trang UniversityNha Trang650000Vietnam Robotics and Mechatronics Research Group Faculty of Engineering and TechnologyNguyen Tat Thanh UniversityHo Chi Minh City700000Vietnam Department of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City700000Vietnam

With the advancement of artificial intelligence,traffic forecasting is gaining more and more interest in optimizing route planning and enhancing service *** volume is an influential parameter for planning and operating traffic *** study proposed an improved ensemble-based deep learning method to solve traffic volume prediction problems.A set of optimal hyperparameters is also applied for the suggested approach to improve the performance of the learning *** fusion of these methodologies aims to harness ensemble empirical mode decomposition’s capacity to discern complex traffic patterns and long short-term memory’s proficiency in learning temporal ***,a dataset for automatic vehicle identification is obtained and utilized in the preprocessing stage of the ensemble empirical mode decomposition *** second aspect involves predicting traffic volume using the long short-term memory ***,the study employs a trial-and-error approach to select a set of optimal hyperparameters,including the lookback window,the number of neurons in the hidden layers,and the gradient descent ***,the fusion of the obtained results leads to a final traffic volume *** experimental results show that the proposed method outperforms other benchmarks regarding various evaluation measures,including mean absolute error,root mean squared error,mean absolute percentage error,and *** achieved R-squared value reaches an impressive 98%,while the other evaluation indices surpass the *** findings highlight the accuracy of traffic pattern ***,this offers promising prospects for enhancing transportation management systems and urban infrastructure planning.

关键词： Ensemble empirical mode decomposition traffic volume prediction long short-term memory optimal hyperparameters deep learning

Analysis of an Ar plasma jet in a dielectric barrier discharge conjugated with a microsecond pulse

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Plasma Science and Technology 2019年第9期21卷 73-81页

作者： Duc Ba nguyen quang Hung TRINH Won Gyu LEE Young Sun MOK Department of Chemical and Biological Engineering Jeju National University Jeju 63243 Republic of Korea Center for Advanced Chemistry Institute of Research and Development Duy Tan University 03 Quang Trung Da Nang Vietnam Division of Chemical Engineering and Bioengineering Kangwon National University Chuncheon Kangwon 24341 Republic of Korea

In this work, an Ar plasma jet generated by an AC-microsecond-pulse-driven dielectric barrier discharge reactor, which had two ring-shaped electrodes isolated from the ambient atmosphere by transformer oil, was investigated. By special design of the oil insulation, a chemically active Ar plasma jet along with a safe and stable plasma process as well as low emission of CO and NOxwere successfully achieved. The results indicated that applied voltage and frequency were basic factors influencing the jet temperature, discharge power, and jet length, which increased significantly with the two operating parameters. Meanwhile, gas velocity affected the jet temperature in a reverse direction. In comparison with a He plasma jet, the Ar plasma jet had relatively low jet temperature under the same level of the input parameters, being preferable for bio-applications. The Ar plasma jet has been tested to interact with human skin within 5 min without the perception of burnt skin and electrical shock.

关键词： Ar plasma jet atmospheric pressure plasma jet OES of Ar gas emission of Ar plasma jet transformer oil

Tungsten-based nanocatalysts with different structures for visible light responsive photocatalytic degradation of bisphenol A

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Journal of Environmental Sciences 2024年第5期139卷 569-588页

作者： Hai Bang truong Thi Thu Loan Doan nguyen Tien Hoang nguyen Van Tam Minh Kim nguyen Le Gia Trung Jin Seog Gwag nguyen Tien Tran Optical Materials Research Group Science and Technology Advanced InstituteVan Lang UniversityHo Chi Minh CityViet Nam Faculty of Applied Technology School of TechnologyVan Lang UniversityHo Chi Minh CityViet Nam The University of Da Nang University of Science and Technology54 Nguyen Luong BangDa NangViet Nam The University of Da Nang University of Science and Education459 Ton Duc Thang St.Lien ChieuDa Nang 550000Viet Nam Institute of Veterinary Science and Technology 31ha zoneTrau QuyGia LamHa Noi 12400Viet Nam Department of Physics Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea Center for Advanced Chemistry Institute of Research and DevelopmentDuy Tan University03 Quang TrungDa Nang 550000Viet Nam Faculty of Natural Sciences Duy Tan University03 Quang TrungDa Nang 550000Viet Nam

Environmental pollution,such as water contamination,is a critical issue that must be absolutely ***,three different morphologies of tungsten-based photocatalysts(WO_(3)nanorods,WO_(3)/WS_(2)nanobricks,WO_(3)/WS_(2)nanorods)are made using a simple hydrothermal method by changing the solvents(H_(2)O,DMF,aqueous HCl solution).The as-prepared nanocatalysts have excellent thermal stability,large porosity,and high *** results show all materials have good photocatalytic activity in aqueous media,with WO_(3)/WS_(2)nanorods(NRs)having the best activity in the photodegradation of bisphenol A(BPA)under visible-light *** may originate from increased migration of charge carriers and effective prevention of electron–hole recombination in WO_(3)/WS_(2)NRs,whereby this photocatalyst is able to generate more reactive·OH and·O_(2)^(–)species,leading to greater photocatalytic *** 99.6% of BPA is photodegraded within 60 min when using 1.5 g/L WO_(3)/WS_(2)NRs and 5.0 mg/L BPA at pH ***,the optimal conditions(pH,catalyst dosage,initial BPA concentration)for WO_(3)/WS_(2)NRs are also elaborately *** rod-like heterostructures are expressed as potential catalysts with excellent photostability,efficient reusability,and highly active effectivity in different types of *** particular,the removal efficiency of BPA by WO_(3)/WS_(2)NRs reduces by only 1.5% after five recycling runs and even reaches 89.1%in contaminated lake *** study provides promising insights for the nearly complete removal of BPA from wastewater or different water resources,which is advantageous to various applications in environmental remediation.

关键词： Photodegradation Bisphenol A Tungsten-based nanocatalyst Structure Nanorod