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Acta Mathematica Scientia 2022年第2期42卷 795-812页

作者： nguyen xuan linh Duong Viet THONG Prasit CHOLAMJIAK Pham Anh TUAN Luong Van LONG Department of Mathematics Mathematics Falcuty of Information TechnologyNational University of Civil Engineering Division of Applied Mathematics Thu Dau Mot UniversityBinh Duong ProvinceVietnam School of Science University of PhayaoPhayao 56000Thailand Paculty of Mathematical Economics National Economics UniversityHanoi CityVietnam

In this work,we investigate a classical pseudomonotone and Lipschitz continuous variational inequality in the setting of Hilbert space,and present a projection-type approximation method for solving this *** method requires only to compute one projection onto the feasible set per iteration and without any linesearch procedure or additional projections as well as does not need to the prior knowledge of the Lipschitz constant and the sequentially weakly continuity of the variational inequality mapping.A strong convergence is established for the proposed method to a solution of a variational inequality problem under certain mild ***,we give some numerical experiments illustrating the performance of the proposed method for variational inequality problems.

关键词： Inertial method Tseng’s extragradient viscosity method variational inequality problem pseudomonotone mapping strong convergence

Hybrid model to optimize object-based land cover classification by meta-heuristic algorithm:an example for supporting urban management in Ha Noi,Viet Nam

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International Journal of Digital Earth 2019年第10期12卷 1118-1132页

作者： Quang-Thanh Bui Manh Pham Van nguyen Thi Thuy Hang Quoc-Huy nguyen nguyen xuan linh Pham Minh Hai Tran Anh Tuan Pham Van Cu Center for Applied Research in Remote sensing and GIS(CARGIS) VNU University of ScienceHa NoiViet Nam VNU University of Science Ha NoiViet Nam Vietnam Institute of Geodesy and Cartography Ha NoiViet Nam Ministry of Education and Training Ha NoiViet Nam

This study proposed a novel object-based hybrid classification model named GMNN that combines Grasshopper Optimization Algorithm(GOA)and the multiple-class Neural network(MNN)for urban pattern detection in Hanoi,*** bands of SPOT 7 image and derivable NDVI,NDWI were used to generate image segments with associated attributes by PCI Geomatics *** segments were classified into four urban surface types(namely water,impervious surface,vegetation and bare soil)by the proposed ***,three training and validation datasets of different sizes were used to verify the robustness of this *** all tests,the overall accuracies of the classification were approximately 87%,and the Area under Receiver Operating Characteristic curves for each land cover type was ***,the performance of this model was examined by comparing several statistical indicators with common benchmark *** results showed that GMNN out-performed established methods in all comparable *** results suggested that our hybrid model was successfully deployed in the study area and could be used as an alternative classification method for urban land cover *** a broader sense,classification methods will be enriched with the active and fast-growing contribution of metaheuristic algorithms.

关键词： Urban remote sensing object-based classification neural network grasshopper optimization algorithm

An Efficient Adaptive Hierarchical Sliding Mode Control Strategy Using Neural Networks for 3D Overhead Cranes

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International Journal of Automation and computing 2019年第5期16卷 614-627页

作者： Viet-Anh Le Hai-xuan Le linh nguyen Minh-xuan Phan Department of Automatic Control Hanoi University of Science and TechnologyHanoi 10000Vietnam Centre for Autonomous Systems University of Technology SydneyNew South Wales 2007Australia

In this paper, a new adaptive hierarchical sliding mode control scheme for a 3D overhead crane system is proposed. A controller is first designed by the use of a hierarchical structure of two first-order sliding surfaces represented by two actuated and un-actuated subsystems in the bridge crane. Parameters of the controller are then intelligently estimated, where uncertain parameters due to disturbances in the 3D overhead crane dynamic model are proposed to be represented by radial basis function networks whose weights are derived from a Lyapunov function. The proposed approach allows the crane system to be robust under uncertainty conditions in which some uncertain and unknown parameters are highly difficult to determine. Moreover, stability of the sliding surfaces is proved to be guaranteed. Effectiveness of the proposed approach is then demonstrated by implementing the algorithm in both synthetic and reallife systems, where the results obtained by our method are highly promising.

关键词： 3D overhead crane adaptive control hierarchical sliding mode control neural network radial basis function

Shear strength model of the reinforced concrete beams with embedded through-section strengthening bars

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Frontiers of Structural and Civil Engineering 2022年第7期16卷 843-857页

作者： linh Van Hong BUI Phuoc Trong nguyen Faculty of Civil Engineering Ho Chi Minh City Open UniversityHo Chi Minh City 700000Vietnam

In this study,finite element(FE)analysis is utilized to investigate the shear capacity of reinforced concrete(RC)beams strengthened with embedded through-section(ETS)*** of critical variables on the beam shear strength,including the compressive strength of concrete,stiffness ratio between ETS bars and steel stirrups,and use of ETS strengthening system alone,are parametrically investigated.A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened *** expression for the maximum bond stress of the ETS bars to concrete is *** new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion *** results obtained from the FE models and analytical models are validated by comparison with those measured from the ***,the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing *** results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.

关键词： embedded through-section strengthening fiber-reinforced polymer finite element shear strength model bond mechanism

Understanding gastric metastasis of small cell lung carcinoma:Insights from case reports and clinical implications

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World Journal of Gastroenterology 2024年第47期30卷 5092-5096页

作者： Nhi Thi Y nguyen Thang Viet Luong Dat xuan nguyen linh Duy Le Hai nguyen Ngoc Dang Department of Internal Medicine University of Medicine and PharmacyHue UniversityHue 530000Viet Nam Faculty of Medicine Duy Tan UniversityDa Nang 550000Viet Nam

Small cell lung cancer(SCLC)is a common type of primary lung cancer that contributes to approximately 15%of *** is closely associated with tobacco risk *** is also known as a type of lung cancer that has a high mortality rate within a short time due to its rapid growth rate(with tumor doubling time of 30 days)and its tendency to metastasize early in the disease *** primary sites of metastasis in SCLC are similar to those in other primary lung cancers and often include the brain,bones,adrenal glands,liver,and lymph ***,there are a few clinical reports of uncommon metastases,such as gastric metastasis from *** the incidence of this clinical presentation is very low,reported cases have generally resulted in early mortality due to inadequate *** purpose of this letter is to discuss the knowledge related to gastric metastasis from SCLC and remind clinical doctors not to miss atypical symptoms,thereby providing the right attitude to improve the prognosis for these patients.

关键词： Gastric metastasis Small cell lung cancer Primary lung cancer Immunohistochemistry Clinical cases

Landslide Susceptibility Mapping Using RBFN-Based Ensemble Machine Learning Models

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 467-500页

作者： Landslide Susceptibility Mapping Using RBFN-Based Ensemble Machine Learning Models Duc-Dam nguyen nguyen Viet Tiep Quynh-Anh Thi Bui Hiep Van Le Indra Prakash Romulus Costache Manish Pandey Binh Thai Pham Faculty of Civil Engineering University of Transport TechnologyThanh XuanHa Noi100000Vietnam Faculty of Hydraulic Engineering Hanoi University of Civil EngineeringHa Noi100000Vietnam DDG(R)Geological Survey of India Gandhinagar382010India Research Institute of the University of Bucharest Bucharest050663Romania National Institute of Hydrology and Water Management Bucharest013686Romania Department of Civil Engineering Transilvania University of BrasovBrasov500152Romania Danube Delta National Institute for Research and Development Tulcea820112Romania Marwadi University Research Center(MURC) Marwadi UniversityRajkotGujaratBharat360003India Department of Civil Engineering Faculty of Engineering&TechnologyMarwadi UniversityRajkotGujaratBharat360003India

This study was aimed to prepare landslide susceptibility maps for the Pithoragarh district in Uttarakhand,India,using advanced ensemble models that combined Radial Basis Function Networks(RBFN)with three ensemble learning techniques:DAGGING(DG),MULTIBOOST(MB),and ADABOOST(AB).This combination resulted in three distinct ensemble models:DG-RBFN,MB-RBFN,and ***,a traditional weighted method,Information Value(IV),and a benchmark machine learning(ML)model,Multilayer Perceptron Neural Network(MLP),were employed for comparison and *** models were developed using ten landslide conditioning factors,which included slope,aspect,elevation,curvature,land cover,geomorphology,overburden depth,lithology,distance to rivers and distance to *** factors were instrumental in predicting the output variable,which was the probability of landslide *** analysis of the models’performance indicated that the DG-RBFN model,with an Area Under ROC Curve(AUC)of 0.931,outperformed the other *** AB-RBFN model achieved an AUC of 0.929,the MB-RBFN model had an AUC of 0.913,and the MLP model recorded an AUC of *** results suggest that the advanced ensemble ML model DG-RBFN was more accurate than traditional statistical model,single MLP model,and other ensemble models in preparing trustworthy landslide susceptibility maps,thereby enhancing land use planning and decision-making.

关键词： Landslide susceptibility map spatial analysis ensemble modelling information values(IV)

Concentrations of Heavy Metals in Muscle with Relation to the Growth of Two Marine Fish Species

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生态毒理学报 2015年第3期10卷 304-310页

作者： Le Quang Dung nguyen Viet linh nguyen xuan Thanh nguyen Duc Cu Vu Van Tu3 Takaomi Arai Institute of Marine Environment and Resources Vietnam Academic of Science and Technology Haiphong Vietnam Institute of Oceanography and Environment Universiti Malaysia Terengganu Kuala Terengganu Malaysia Institute of Environmental Technology Vietnam Academic of Science and Technology Hanoi Vietnam

Heavy metal concentrations in muscle and their relation to thegrowth of two marine fish species,including tonguefish( Cynoglossus arel) and mullet( Mugil cephalus),were studied. The samples were collected in Bach Dang estuary andconcentrations of heavy metals( As,Cd,Co,Mn,Cu,Zn,Pb,and V) in muscle of the fisheswere determined. The result showed that the accumulated trend of heavy metal is different between fish species. The concentration of As,Zn,Mn,V,Cu,Pb,Co and Cd in tonguefish were 73. 7 ± 30. 6,22. 82 ± 4.87,3. 44 ± 2. 13,1. 61 ± 0. 15,0. 71 ± 0. 13,0. 45 ± 0. 24,0. 03 ± 0. 02 and 0. 02 ± 0. 02 mg·g-1,respectively. Meanwhile the concentration of Zn,As,V,Mn,Cu,Pb,Co and Cd in mullet were 83. 41 ±19. 68,9. 78 ± 1. 92,1. 36 ± 0. 54,1. 29 ± 0. 51,0. 65 ± 0. 12,0. 42 ± 0. 20,0. 06 ± 0. 03 and0. 03 ± 0. 01mg·g-1,respectively. Comparison of metal levels among thesespecies indicated that the concentrations of As and Mn in tonguefish were significantly higher than those in mullet,whereas Zn levels in mullet were found to be higher than that in tonguefish. There is no significant differences of Cd,Co,Cu,Pb and V levels in muscle between two species. Significant inversed relationshipsbetween concentration levels of metals and lengths of tonguefish were found for Mn,Cu and Zn,butnot for As,Cd,Pb,and V. There were no significant relationships between the heavy metal concentrations and the length of mullet. In general,decreasesof the heavy metal concentrations corresponded to the increases of fish body lengths,particularly for As,Co,Cu,Mn and V and the exception for Cd. Terefore reduced risks were associated with consuming biggermullet fish,and increased risks of As and Cd were associated with consuming bigger tonguefish in Bach Dang river mouth.

关键词： heavy metals concentration levels marine fish health risk Vietnam

Liouvillian Solutions of Algebraic Ordinary Differential Equations of Order One of Genus Zero

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Journal of Systems Science & Complexity 2023年第2期36卷 884-893页

作者： nguyen Tri Dat NGO Lam xuan Chau Faculty of Basic Science Ho Chi Minh City University of TransportHo Chi Minh CityVietnam Department of Mathematics and Statistics Quy Nhon UniversityQuy Nhon CityVietnam

This paper considers the class of autonomous algebraic ordinary differential equations(AODEs)of order one,and studies their Liouvillian general *** particular,let F(y,w)=0 be a rational algebraic curve over *** authors give necessary and sufficient conditions for the autonomous first-order AODE F(y,y′)=0 to have a Liouvillian solution over ***,the authors show that a Liouvillian solutionαof this equation is either an algebraic function over C(x)or an algebraic function over C(exp(ax)).As a byproduct,these results lead to an algorithm for determining a Liouvillian general solution of an autonomous AODE of order one of genus *** parametrizations of rational algebraic curves play an important role on this method.

关键词： Algebraic ordinary differential equation autonomous differential equation Liouvillian solution rational algebraic curve rational parametrizations

Discrete-time sliding mode control with power rate exponential reaching law of a pneumatic artificial muscle system

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Control Theory and Technology 2022年第4期20卷 514-524页

作者： Quy-Thinh Dao Trung-Kien Le Tri Van-Anh nguyen Manh-linh nguyen School of Electrical and Electronic Engineering Hanoi University of Science and TechnologyDai Co VietHanoi 11615Vietnam

This paper develops a discrete-time sliding mode controller with a power rate exponential reaching law approach to enhance the performance of a pneumatic artificial muscle system in both reaching time and chattering *** proposed method dynamically adapts to the variation of the switching function,which is based on an exponential term and a power rate term of the sliding ***,the controlled system can achieve high tracking performance while still obtain chattering-free ***,the effectiveness of the proposed method is validated through multiple experimental tests,focused on a dual pneumatic artificial muscle ***,experimental results show the effectiveness of the proposed approach in this paper.

关键词： Pneumatic artificial muscle Discrete-time sliding mode control Exponential reaching law Chattering

Assessment by microsatellite analysis of genetic diversity and population structure of Enhalus acoroides from the coast of Khanh Hoa Province, Vietnam

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Acta Oceanologica Sinica 2019年第1期38卷 144-150页

作者： xuan-Vy nguyen Papenbrock Jutta Department of Marine Botany Institute of Oceanography Vietnam Academy of Science and Technology Graduate University of Science and Technology Institute of Botany Leibniz University Hannover

Seagrass beds degraded significantly since the last century on both, global and local scale. The seagrass species Enhalus acoroides(Linnaeus f.) Royle is a common species found in almost all marine ecosystems including bays,lagoons and around offshore islands in tropical regions of the West Pacific. It was shown that genetic diversity is an essential indicator of the conditions of ecosystems. In the present study, microsatellite markers were used to assess the genetic diversity and population structure of six distinct seagrass beds along the coast of the Khanh Hoa Province, Vietnam. The results indicate that the genetic diversity of the populations in the open sea is higher than in the lagoon. Seagrass beds occurring in disturbed sites show reduced genetic diversity. The fixing index value(FST) depicts a relatively high genetic structure among populations. Structure analysis clusters the populations into open sea and lagoon populations and cluster analysis and AMOVA indicate a significant difference between the two groups. There are low but non-significant positive correlations between geographic and genetic *** different habitats of the open sea and the lagoon are probably responsible for forming two groups.

关键词： Enhalus acoroides genetic diversity lagoon open sea population structure