检索结果-南通市图书馆

Study of vertically ascending flight of a hawkmoth model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2020年第5期36卷 1031-1045,I0002页

作者： Anh Tuan Nguyen Vu Dan Thanh Le the hung tran V.N.Due Van Binh Phung Faculty of Aerospace Engineering Le Quy Don Technical UniversityHanoiVietnam Institute of Theoretical and Applied Research.Duy Tan University HanoiVietnam Division of Construction Computation Institute for Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

This paper provides insight into the wing kinematics,the power requirement and the dynamic stability characteristics of a hawkmoth model in vertically ascending flight.The wing kinematics of the hawkmoth model is obtained based on the minimum required power assumption.The optimization process is conducted using genetic and simplex algorithms that are coupled with an artificial neural network to rapidly predict the aerodynamic force and required power.The training data for the neural network are generated from an unsteady vortex-lattice method.Compared to hover,the results in this study show the larger flapping frequency and the smaller rotation amplitude of the hawkmoth wing kinematics in ascending flight.Additionally,more power is required when the ascending speed increases.While conducting a dynamic modal analysis based on a cycle-average approach,the certain effect of the ascending speed on the modal structures of the hawkmoth model was observed.

关键词： Hawkmoth Ascending flapping flight-Genetic algorithm Artificial neural network Flight dynamic stability

Defatted black soldier fly (Hermetia illucens) in pikeperch (Sander lucioperca) diets: Effects on growth performance, nutrient digestibility, fillet quality, economic and environmental sustainability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2023年第1期12卷 7-19页

作者： Vlastimil Stejskal hung Quang tran Markéta Prokesová Mahyar Zare Tatyana Gebauer Tomas Policar Christian Caimi Francesco Gai Laura Gasco University of South Bohemia in Ceske Budejovice Faculty of Fisheries and Protection of WatersSouth Bohemian Research Center of Aquaculture and Biodiversity of HydrocenosesHusova tr.458/10237005 CeskéBudějoviceCzech Republic University of Torino Department of AgriculturalForest and Food SciencesLargo P.Braccini 210095 GrugliascoItaly National Research Council Institute of Sciences of Food ProductionLargo P.Braccini 210095 GrugliascoItaly

The use of insect meal in aquafeed formulations has recently gained attention.Detailed knowledge about the inclusion levels for pikeperch(Sander lucioperca),a promising candidate for intensive aquaculture in Europe remains,however,fragmented.In the present study,4 isoproteic(45%dry matter)and isoenergetic(21 MJ/kg)diets were formulated,including a control diet(H0)containing 30%fishmeal(FM)on an as-fed basis and the other 3 diets in which FM protein was replaced by defatted black soldier fly(Hemetia illucens)meal(HIM)at 25%,50%,and 100%(diet abbreviation H9,H18 and H36,corresponding to an inclusion level of 9%,18%and 36%,respectively).The feeding trial was performed in triplicate groups of 50 juvenile pikeperch(mean weight,68.7 g)fed with experimental diets for 84 d during which the growth performance,nutrient digestibility,fillet quality and economic and environmental sustainability of rearing pikeperch were evaluated.Our findings indicated that pikeperch in H0,H9,and H18 groups displayed better results regarding growth performance indices,except for survival rate where no significant difference among groups was recorded(P?0.642).A significantly lower organ-somatic index,including hepatosomatic,viscerosomatic and perivisceral fat index,was found in fish in H18 groups than other groups(P0.05)but did reduce total n-3 fatty acids(P?0.001)and increased total n-6(P<0.001).Increasing inclusion levels of HIM reduced the environmental impacts associated with fish in-to-fish out ratio but entailed heavy burdens on energy use and eutrophication.Low and moderate in

关键词： Alternative feed Digestibility Fish in-to-fish out ratio Insect meal Percids Sustainability

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

在线全文

学校读者我要写书评

暂无评论

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 investigated.The communication protocol is divided into two phases.In 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)technique.Simultaneously,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 performance.Furthermore,the intercept probability(IP)and throughput of the considered IoT architecture are determined.Accordingly,we identify the optimal altitudes for the UR and UJ to enhance the system and secrecy performance.Monte 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

Isolation and Identification of Two Flavonoid Compounds from Acclimatized Angelica acutiloba Kitagawa Growing in Vietnam

在线全文

学校读者我要写书评

暂无评论

World Journal of Traditional Chinese Medicine 2022年第3期8卷 413-416页

作者： Thi Minh Tam Pham Thi Thu Cuc Le Viet hung tran Van Thanh Nguyen Department of Microbiology Institute of Drug Quality ControlDepartment of Analytical Chemistry and Quality ControlUniversity of Medicine and PharmacyHo Chi Minh CityVietnam Department of Analytical Chemistry and Quality Control Nguyen Tat Thanh UniversityHo Chi Minh CityVietnam Department of Microbiology Institute of Drug Quality ControlHo Chi Minh CityVietnam

Traditional Vietnamese Medicine has its own development based on the local endemic herbs,but it also inherits from Traditional Chinese Medicine using Chinese herbal medicines.Throughout the history of cultural exchange between two countries,the adoption of Chinese Danggui,Angelica sinensis(Oliv.)Diels.,has been made by Vietnamese traditional medicine practitioners for a long time.However,the acclimatization has never been successful.Japanese Danggui,or Angelica acutiloba Kitagawa,is recently being acclimatized and cultivated in several Vietnamese regions.Despite the huge climate change between the two countries,the herb adapted exquisitely well to the humid tropical climate.However,so far,there are no studies that have evaluated the effect of acclimatization on the overall quality of this medicinal herb.The aim of our study is screening secondary metabolites of this acclimatized herb for new natural compound(s),if any.The analysis of flavonoid fraction from this herb led to the identification of two known compounds which previously have not been isolated from this species elsewhere.This detection showed that the herb has reacted to the new environment.

关键词： Abiotic stress Angelica acutiloba danggui isoquercitrin rutin

Single-Layer Wideband Circularly Polarized Antenna Using Non-Uniform Metasurface for C-band Applications

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第8期68卷 2487-2498页

作者： Huy hung tran Khoa Nguyen-Dang Niamat Hussain Faculty of Electrical and Electronic Engineering PHENIKAA UniversityHanoi12116Vietnam PHENIKAA Research and Technology Institute(PRATI) A&A Green Phoenix Group JSCCau Giay11313HanoiVietnam Department of Computer and Communication Engineering Chungbuk National UniversityCheongju 28644Korea

A single-layer design of non-uniform metasurface(MS)based circularly polarized(CP)antenna with wideband operation characteristic is proposed and investigated in this paper.The antenna is excited by a truncated corner squared patch as a primary radiating CP source.Then,a non-uniform MS is placed in the same layer with the driven patch.Besides increasing the impedance bandwidth,the non-uniform MS also generates two additional CP bands in the high frequency band,leading to significantly increase the antenna’s overall performances.The use of non-uniform MS distinguishes our design from the other CP MS based antennas in literature,in which the MS is formed by multiple uniform unit cells and placed in different layer with the radiating element.For validation,an antenna prototype,whose overall dimensions of 0.94λ_(o)×0.94λ_(o)×0.06λ_(o) at the center operating frequency,is fabricated and experimentally tested.The measured operating bandwidth with|S11|≤−10 dB and AR≤3 dB is 27.1%(5.1–6.7 GHz)and the broadside gain within this band is from 5.7 to 7.2 dBic.Compared to the other related works,the proposed antenna has advantage of very wideband operation with single-layer design.

关键词： Circular polarization metasurface non-uniform patch antenna wideband

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 quality.Traffic volume is an influential parameter for planning and operating traffic structures.This 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 process.The 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 relationships.Firstly,a dataset for automatic vehicle identification is obtained and utilized in the preprocessing stage of the ensemble empirical mode decomposition model.The second aspect involves predicting traffic volume using the long short-term memory algorithm.Next,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 optimization.Finally,the fusion of the obtained results leads to a final traffic volume prediction.The 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 R-squared.The achieved R-squared value reaches an impressive 98%,while the other evaluation indices surpass the competing.These findings highlight the accuracy of traffic pattern prediction.Consequently,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

Cell-type resolved transcriptomic approaches for dissecting selective vulnerability in neurodgeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1411-1413页

作者： Caleb A.Wood Nicholas M.tran Department of Neuroscience Baylor College of MedicineHoustonTXUSA Department of Molecular and Human Genetics Baylor College of MedicineHoustonTXUSA

A common feature among neurodegenerative conditions is that ce rtain neuronal populations are selectively vulnerable to loss(Fu et al.,2018).By corollary,other neurons are selectively resilient,suggesting they may possess unique features that support their survival.U nderstanding the basis of neuronal resilience or vulnerability would provide a logical strategy to identify factors that could be targeted therapeutically.

关键词： selective targeted

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

在线全文

学校读者我要写书评

暂无评论

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 developed.The mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding stages.The simulation findings are compared to the analytical calculation results in the steady state,and both methods show good agreement.In the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model 2.Meanwhile,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting stage.The established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system operation.It 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

Random vibration analysis of FGM plates subjected to moving load using a refined stochastic finite element method

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 42-56页

作者： Ngoc-Tu Do Trung Thanh tran Faculty of Mechanical Engineering Hanoi University of IndustryHanoiViet Nam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoiViet Nam

The article introduces a finite element procedure using the bilinear quadrilateral element or four-node rectangular element(namely Q4 element) based on a refined first-order shear deformation theory(rFSDT) and Monte Carlo simulation(MCS), so-called refined stochastic finite element method to investigate the random vibration of functionally graded material(FGM) plates subjected to the moving load.The advantage of the proposed method is to use r-FSDT to improve the accuracy of classical FSDT, satisfy the stress-free condition at the plate boundaries, and combine with MCS to analyze the vibration of the FGM plate when the parameter inputs are random quantities following a normal distribution. The obtained results show that the distribution characteristics of the vibration response of the FGM plate depend on the standard deviation of the input parameters and the velocity of the moving load.Furthermore, the numerical results in this study are expected to contribute to improving the understanding of FGM plates subjected to moving loads with uncertain input parameters.

关键词： FGM Moving load R-FSDT Q4 element Monte Carlo simulation Random vibration