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IET Cyber-Systems and Robotics 2024年第3期6卷 31-48页

作者： Khanh Nguyen Viet minh do duc Thanh Cao duc Tung Lam Nguyen School of Electrical and Electronic Engineering Hanoi University of Science and TechnologyHanoiVietnam Vietnam Maritime University HaiphongVietnam

The phenomenon of sloshing causes a significantly negative impact on a wide range of industries.A time‐optimal flatness‐based trajectory planning and Lyapunov‐based model predictive control(LMPC)is proposed for trajectory tracking of a transmitting cylindrical container filled with ***,this research presents an equivalent discrete model based on a mass‐spring‐damper ***,after the flatness of the adopted non‐linear model for 2D is established,time‐optimal trajectories are introduced.A control method called LMPC is shown to solve the problem of orbital tracking,which allows setting limits for state *** addition,to ensure system performance,a linear extended state observer(LESO)is integrated to cope with system ***,the efficiency of the proposed approach for liquid sloshing suppression and tracking is illustrated by simulations.

关键词： control dynamic model motion planning

Sediment transport trends and cross-sectional stability of a lagoonal tidal inlet on the Central Coast of Vietnam

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International Journal of Sediment Research 2019年第4期34卷 322-334页

作者： do minh duc Tran Thanh Tung Patrick Mc Laren Tran Ngoc Anh Dinh Thi Quynh Faculty of Geology VNU University of Science Vietnam National University Faculty of Marine and Coastal Engineering Thuyloi University Sed Trend Analysis Limited 4. Faculty of Meteorology Hydrology and Oceanography VNU University of Science Vietnam National University

Lagoonal tidal inlets are a typical morphology of the Central Coast of Vietnam. Recently, navigation channels in these inlets have become increasingly threatened by siltation. This study analyses the relations between sediment distribution and transport trends(using the technique of Sediment Trend Analysis-STAs) in the lagoonal system of the De Gi inlet and then proposes appropriate countermeasures against sand deposition in the navigation channel. The STA identified three types of transport trends in the De Gi inlet, namely dynamic equilibrium, net accretion, and net erosion. Processes associated with the tidal prism have resulted in trends of sediment transport and deposition across the flood and ebb tidal shoals, which maintain a present cross-sectional area of about 1000 m~2. However, longshore sediment transport from north to south resulting from northeast waves cause additional sand deposition in the channel. In addition, the effects of refraction associated with a nearby headland and jetty also increase sedimentation. These processes provide the main reasons for sediment deposition in the De Gi inlet. Short term and regular dredging helps to maintain the navigation channel. A system comprised of three jetties(north, south, and weir) is necessary to ensure the longterm cross-sectional stability of the navigation channel.

关键词： Lagoon Tidal inlet Sediment Trend Analysis (STA) Tidal prism Cross-sectional stability

Stability in Probability and Inverse Optimal Control of Evolution Systems Driven by Levy Processes

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 405-419页

作者： Khac duc do School of Civil and Mechanical Engineering CurtinUniversity

This paper first develops a Lyapunov-type theorem to study global well-posedness(existence and uniqueness of the strong variational solution)and asymptotic stability in probability of nonlinear stochastic evolution systems(SESs)driven by a special class of Levy processes,which consist of Wiener and compensated Poisson *** theorem is then utilized to develop an approach to solve an inverse optimal stabilization problem for SESs driven by Levy *** inverse optimal control design achieves global well-posedness and global asymptotic stability of the closed-loop system,and minimizes a meaningful cost functional that penalizes both states and *** approach does not require to solve a Hamilton-Jacobi-Bellman equation(HJBE).An optimal stabilization of the evolution of the frequency of a certain genetic character from the population is included to illustrate the theoretical developments.

关键词： Evolution system inverse optimal control Levy processes stability in probability well-posedness

Velocity equation for grenades while impacting on dry sand media

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Defence Technology（防务技术） 2024年第5期35卷 168-173页

作者： Martin Macko Xuan Son Bui Kongsathit Phanthavong duc Hung Pham Van Gion do Van minh do Jiri Skala University of Defence BrnoCzech Republic Le Quy don Technical University Ha NoiViet Nam

This paper deals with the collision of sphere shape grenades with sand *** central issue of the article is the establishing of an empirical velocity equation of the grenade while impacting on sand that is used to solve motion equations of the mechanical mechanism inside the impact grenade *** paper focuses on impact velocities that are lower than 5 m s^(-1).An experiment was conducted to study the velocity of the grenade while impacting on dry sand.A high-speed camera video was used to capture the grenade *** grenade velocity in the impact process was generated from these video *** types of fitting curves are used to regress the velocity equation of the grenade while interacting with the sand media and the best-fitting model is *** result shows the regression curve has a high correlation with the experiment data for grenade velocities below 5 m s^(-1).The received regression equation is useful for analyzing the working ability of the inertial mechanism inside the impact grenade or analyzing and choosing the appropriate parameters of each part in the inertial mechanism to meet the required characteristics of the mechanism.

关键词： Dynamic response Impact velocity Impact grenade Low-velocity impact

Kriging-based reliability analysis of the long-term stability of a deep driftconstructed in the Callovo-Oxfordian claystone

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1033-1046页

作者： Ngoc-Tuyen Tran duc-Phi do Dashnor Hoxha minh-Ngoc Vu Gilles Armand Univ.Orléans Univ.ToursINSA CVLLaméEA 7494France Andra R&D Division92298Chatenay-MalabryFrance

Callovo-Oxfordian(COx)claystone has been considered as a potential host rock for geological radioactive waste disposal in France(Cigéo project).During the exploitation phase(100 years),the stability of drifts(***/alveoli)within the disposal is assured by the liner,which includes two layers:concrete arch segment and compressible *** latter exhibits a significant deformation capacity(about 50%)under low stress(<3 MPa).Although the response of these underground structures can be governed by complex thermo-hydro-mechanical coupling,the creep behavior of COx claystone has been considered as the main factor controlling the increase of stress state in the concrete liner and hence the long-term stability of ***,by focusing only on the purely mechanical behavior,this study aims at investigating the uncertainty effect of the COx claystone time-dependent properties on the stability of an alveolus of Cigéo during the exploitation *** describe the creep behavior of COx claystone,we use Lemaitre’s viscoplastic model with three parameters whose uncertainties are identified from laboratory creep *** the reliability analysis,an extension of a well-known Kriging metamodeling technique is proposed to assess the exceedance probability of acceptable stress in the concrete liner of the *** open-source code Code_Aster is chosen for the direct numerical evaluations of the performance *** Kriging-based reliability analysis elucidates the effect of the uncertainty of COx claystone on the long-term stability of the concrete ***,the role of the compressible material layer between the concrete liner and the host rock is also highlighted.

关键词： Reliability analysis Kriging metamodeling Time-dependent behavior Compressible material Callovo-Oxfordian(COx)claystone Long-term stability

A comparative study of three different learning algorithms applied to ANFIS for predicting daily suspended sediment concentration

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International Journal of Sediment Research 2017年第3期32卷 340-350页

作者： Keivan Kaveh minh duc Bui Peter Rutschmann Department of hydraulic and water resource engineering/School of civil engineering Technische Universitt Mnchen (TUM)

The modeling and prediction of suspended sediment in a river are key elements in global water recourses and environment policy and management. In the present study, an Adaptive Neuro-Fuzzy Inference System model trained with the Levenberg-Marquardt learning algorithm is considered for time series modeling of suspended sediment concentration in a river. The model is trained and validated using daily river discharge and suspended sediment concentration data from the Schuylkill River in the United States. The results of the proposed method are evaluated and compared with similar networks trained with the common Hybrid and Back-Propagation algorithms, which are widely used in the literature for prediction of suspended sediment concentration. Obtained results demonstrate that models trained with the Hybrid and Levenberg-Marquardt algorithms are comparable in terms of prediction ***, the networks trained with the Levenberg-Marquardt algorithm perform better than those trained with the Hybrid approach.

关键词： Fuzzy Inference System Hybrid learning rule Levenberg-Marquardt algorithm Schuylkill river Suspended sediments

Structural and luminescent properties of (Eu,Tb) PO_4·H_2O nanorods/nanowires prepared by microwave technique

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Journal of Rare Earths 2011年第12期29卷 1170-1173页

作者： Nguyen Thanh Huong Nguyen duc Van Dinh Manh Tien do Khanh Tung Nguyen Thanh Binh Tran Kim Anh Le Quoc minh Institute of Materials Science Vietnam Academy of Science and Technology University of Engineering and Technology National University HanoiVietnam

Nanowires/nanorods of europium/terbium orthophosphate monohydrate with Eu^3＋ concentration of 6, 11, and 20 at.% were prepared by microwave synthesis method. The effects of Eu^3＋ doping concentration on structure, morphology and optical properties of nanomaterials were also investigated. The results showed that, for all studied Eu^3＋ doping concentrations, a single-crystalline phase of rhabdophane-type （Eu,Tb）PO4·H2O nanowires/nanorods was obtained by using microwave heating of an aqueous solution of terbium（Ⅲ） nitrate, europium（Ⅲ） nitrate and NH4H2PO4 with pH=2. The length and width of these nanowires/nanorods ranged from 150 to 300 nm and from 10 to 50 nm, respectively. The evidence of energy transfer from Tb^3＋ to Eu^3＋ due to the energy overlap between the donor Tb^3＋ and the acceptor Eu^3＋was observed obviously via a significant enhancement in the luminescent intensity of Eu^3＋. Keywords：

关键词： microwave technique nanowires/nanorods energy transfer fluorescence spectroscopy rare earths

An isogeometric approach to free vibration analysis of bi-directional functionally graded porous doubly-curved shallow microshells with variable length-scale parameters

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Frontiers of Structural and Civil Engineering 2023年第12期17卷 1871-1894页

作者： Khuat duc DUONG Dao Nhu MAI Phung Van minh Tran Van KE Faculty of Mechanical Engineering Hanoi University of IndustryHanoi 100000Vietnam Institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 100000Vietnam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi 100000Vietnam

This study uses iso-geometric investigation,which is based on the non-uniform rational B-splines(NURBS)basis function,to investigate natural oscillation of bi-directional functionally graded porous(BFGP)doublycurved shallow microshells placed on Pasternak foundations with any boundary *** characteristics of the present material vary in both thickness and axial directions along the *** be more specific,a material length-scale coefficient of the microshell varies in both thickness and length directions as the material's mechanical *** is able to develop a differential equation system with varying coefficients that regulate the motion of BFGP double-curved shallow microshells by using Hamilton principle,Kirchhoff-Love hypothesis,and modified couple stress *** numerical findings are reported for thin microshells that are spherical,cylindrical,and hyperbolic paraboloidal,with a variety of planforms,including rectangles and *** validity and effectiveness of the established model are shown by comparing the numerical results given by the proposed formulations with previously published findings in many specific *** addition,influences of length scale parameters,power-law indexes,thickness-to-side ratio,and radius ratio on natural oscillation responses of BFGP microshells are investigated in detail.

关键词： Kirchhoff-Love's shell theory isogeometric analysis bi-directional functionally graded free vibration variable length-scale parameter

A new species Lobophora tsengii ***.(Dictyotales;Phaeophyceae)from Bach Long Vy(Bailongwei)Island,Vietnam

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Journal of Oceanology and Limnology 2021年第6期39卷 2363-2369页

作者： Zhongmin SUN minh dong DAO Quoc Toan TRAN duc Tien DAM Department of Marine Organism Taxonomy and Phylogeny Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Graduate University of Science and Technology Vietnam Academy of Science and Technology(VAST)Hanoi 100000Vietnam Institute of Natural Products Chemistry Vietnam Academy of Science and Technology(VAST)Cau GiayHanoi 100000Vietnam Institute of Marine Environment and Resources(IMER) Vietnam Academy of Science and Technology(VAST)Haiphong 180000Vietnam Haiphong University of Medicine and Pharmacy Haiphong 180000Vietnam

A new species Lobophora tsengii is described from Bach Long Vy(Bailongwei)Island,Haiphong Province,*** plants inhabit the subtidal zone and have predominantly erect fan-shaped thalli that attach to the substrate by a basal *** thallus is commonly composed of a single layer of large medullary cells with four layers of cortical cells on either side of the *** newly collected specimens from the island are morphologically similar to those from Hainan Island,China,but differ from the New Caledonian ones in having thicker *** molecular phylogenetic analyses based on concatenated rbcL and cox3 s equences,the specimens from the island were 100%identical to those from Hainan Island,China,and they formed a clade separating from other Lobophora ***,based on analyses of numerous cox3 s equences,our specimens were also distinguished from the closely related taxa occurring in New Caledonia,Kenya,and West *** the morphological and molecular analyses,we conclude that our specimens represent a new species of Lobophora,which is apparently endemic to the Beibu Gulf(Gulf of Tonkin)and adjacent waters.

关键词： Bach Long Vy(Bailongwei)Island cox3 Lobophora molecular phylogeny morphology rbcL

Finite element implementation of coupled hydro-mechanical modeling of transversely isotropic porous media in ***

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 173-184页

作者： Hong-Lam Dang duc-Phi do Faculty of Civil Engineering University of Transport and Communications No.3 Cau Giay HanoiVietnam LaM´e Laboratory F-45072University of Orl´eans University of ToursINSA CVLOrl´eansFrance

In geotechnical engineering,modeling geo-structures is challenging,particularly in cases where the interaction between the structures and soil or rock is *** wellknown commercial modeling software is based on homogenous and isotropic ***,soil and rock are often modeled in heterogeneous and anisotropic media because of the inherent anisotropy of sedimentary rock masses and their stratified *** recent decades,coupled hydro-mechanical(HM)interactions in isotropic porous media have been studied;however,the behavior of transversely isotropic porous media is rarely *** addition,it is difficult for commercial software such as Plaxis and Flac3D to express complex rock formation where the anisotropy of the material and the associated cracks and fractures could be assembled into a single *** this study,a finite element implementation using Differential Equation Analysis Library(***),an open-source library of finite element codes,was developed to model the fully coupled HM behavior of transversely isotropic porous *** proposed implementation can be applied to both isotropic and transversely isotropic porous media based on Biot’s *** developed code can be used to model poroelastic media with(1)equations of linear elasticity for the solid matrix and(2)diffusion equations for fluid flow based on mass and linear-momentum conservation *** verified the performance and accuracy of the code through two examples,i.e.,Mandel’s problem with a compared analytical solution and a tunnel excavation process with the Flac3D *** the basis of these numerical applications,we present the code to model the behavior of various geo-structures such as tunnels and pile–soil interactions with anisotropic materials.

关键词： Coupled hydro-mechanical modeling transversely isotropic porous media Biot’s theory finite element method DEAL.II