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World Journal of Nuclear Science and Technology 2015年第3期5卷 183-191页

作者： Nguyen Tuan Khai do xuan anh Le Dinh Cuong Duong Duc Thang Vuong Thu Bac Nguyen Thi Thu Ha Nguyen Quang Long Trinh Van Giap Nguyen Hao Quang Institute for Nuclear Science and Technology (INST) Hanoi Vietnam Vietnam Atomic Energy Institute (VINATOM) Hanoi Vietnam

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC), our research concentrates in assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCdose72 provided by the USNRC. The database including the released radioactive nuclides, meteorology, terrain, population and agricultural production activities have been collected and processed to build the input data for the model calculation. The wind rose distribution obtained from the meteorological data in a five-year period from 2009-2013 showed that the radioactive nuclides released to environment spread in two main wind directions which are North East and South West. The X/Q (s/m3) and D/Q (s/m2) qualities which are, respectively, the ratio of activity concentration to release rate and that of deposition density of radioactive nuclides to release rate were calculated within an area of 80 km radius from the NPP site using XOQdoQ. Population doses were calculated using GASPAR. The XOQdoQ and GASPAR are two specific softwares in NRCdose72 package.

关键词： NPP Radioactive Release Radiation dose Population dose X/Q and D/Q

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

STRONG CONVERGENCE OF AN INERTIAL EXTRAGRADIENT METHOD WITH AN ADAPTIVE NONDECREASING STEP SIZE FOR SOLVING VARIATIONAL INEQUALITIES

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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

Physical activity,COVID-19,and respiratory comorbidities:The good,the bad,and the ugly

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Journal of Sport and Health Science 2023年第2期12卷 216-218页

作者： anh-Tuan Dinh-xuan Thõng Hua-Huy Sven Günther Lung Function&Respiratory Physiology Units Department of Respiratory Physiology and Sleep MedicineAssistance Publique-Hôpitaux de ParisCochin&George Pompidou HospitalsUniversity Paris CitéParis 75006France

Almost 3 years after the outbreak of the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)responsible for the coronavirus disease 2019(COVID-19)that has caused more than 6 million deaths worldwide,1the pandemic persists and hampers our daily *** are at least 2 main reasons explaining why we still struggle to terminate this ***,novel variants of concern of SARS-CoV-2unceasingly emerge despite almost 12 billion doses of vaccinebeing administered to date.

关键词： respiratory doses acute

Building 3D CityGML models of mining industrial structures using integrated UAV and TLS point clouds

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International Journal of Coal Science & Technology 2023年第5期10卷 158-177页

作者： Canh Le Van Cuong xuan Cao anh Ngoc Nguyen Chung Van Pham Long Quoc Nguyen Department of Mine Surveying Hanoi University of Mining and GeologyHanoiVietnam Viettel Group Viettel Cyberspace CenterHanoiVietnam

Mining industrial areas with anthropogenic engineering structures are one of the most distinctive features of the real world.3D models of the real world have been increasingly popular with numerous applications,such as digital twins and smart factory *** this study,3D models of mining engineering structures were built based on the CityGML *** collecting spatial data,the two most popular geospatial technologies,namely UAV-SfM and TLS were *** accuracy of the UAV survey was at the centimeter level,and it satisfied the absolute positional accuracy requirement of creat-ing all levels of detail(LoD)according to the CityGML ***,the UAV-SfM point cloud dataset was used to build LoD 2 *** addition,the comparison between the UAV-SfM and TLS sub-clouds of facades and roofs indicates that the UAV-SfM and TLS point clouds of these objects are highly consistent,therefore,point clouds with a higher level of detail and accuracy provided by the integration of UAV-SfM and TLS were used to build LoD 3 *** resulting 3D CityGML models include 39 buildings at LoD 2,and two mine shafts with hoistrooms,headframes,and sheave wheels at LoD3.

关键词： 3D modelling CityGML-Mining industry UAV Terrestrial laser scanning Point cloud

Investigation of Polymorphisms in Coding Region of OsHKT1in Relation to Salinity in Rice

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Rice science 2016年第6期23卷 334-338页

作者： pham quynh-hoa tran xuan-an nguyen thi-nha-trang tran thi-thuy-anh hoang hai-yen nguyen thi-hong-van tang thi-hanh do thi-phuc Faculty of Biology VNU University of ScienceHanoi334 Nguyen TraiThanh XuanHanoiVietnam Faculty of Agronomy Vietnam National University of AgricultureNgo Xuan Quang StreetTrau QuyGia LamHanoiVietnam

Rice （Oryza sativa） is sensitive to salinity, but the salt tolerance level differs among cultivars,which might result from natural variations in the genes that are responsible for salt tolerance. High-affinitypotassium transporter （HKTs） has been proven to be involved in salt tolerance in plants. Therefore, wescreened for natural nucleotide polymorphism in the coding sequence of OsHKT1, which encodes the HKTprotein in eight Vietnamese rice cultivars differing in salt tolerance level. In total, seven nucleotidesubstitutions in coding sequence of OsHKT1 were found, including two non-synonymous and five synonymoussubstitutions. Further analysis revealed that these two non-synonymous nucleotide substitutions （G50Tand T1209A） caused changes in amino acids （Gly17Val and Asp403Glu） at signal peptide and the loop ofthe sixth transmembrane domain, respectively. To assess the potential effect of these substitutions on theprotein function, the 3D structure of HKT protein variants was modelled by using PHYRE2 webserver. Theresults showed that no difference was observed when compared those predicted 3D structure of HKTprotein variants with each other. In addition, the codon bias of synonymous substitutions cannot clearlyshow correlation with salt tolerance level. It might be interesting to further investigate the functional roles ofdetected non-synonymous substitutions as it might correlate to salt tolerance in rice.

关键词： polymorphism salt stress OsHKT1 gene rice

Effect of Poly-Alkylene-Glycol Quenchant on the Distortion, Hardness, and Microstructure of 65Mn Steel

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Computers, Materials & Continua 2021年第6期67卷 3249-3264页

作者： Thi xuan Tran xuan Phuong Nguyen Duong Nam Nguyen Dinh Toai Vu Minh Quang Chau Osamah Ibrahim Khalaf anh Tuan Hoang Hanoi University of Science and Technology HanoiVietnam Ho Chi Minh City University of Transport Ho Chi Minh CityVietnam Vietnam Maritime University HaiphongVietnam Industrial University of Ho Chi Minh City(IUH) Ho Chi Minh CityVietnam Al-Nahrain Nanorenewable Energy Research Center Al-Nahrain UniversityBaghdadIraq Ho Chi Minh city University of Technology(HUTECH) Ho Chi Minh CityVietnam

Currently,the 65Mn steel is quenched mainly by oil *** though the lower cooling rate of oil compared to water reduces the hardness of steel post quenching,the deforming and cracking of parts are often *** the other hand,the oil media also has the disadvantage of being ammable,creating smoke that adversely affects the *** poly alkylene glycol(PAG)polymer quenchant is commonly used for quenching a variety of steels based on its advantages such as non-ammability and exible cooling rate subjected to varying concentration and stirring *** article examines the effect of PAG polymer quenching solution(with concentrations of 10%and 20%)on deformation,hardness,and microstructure of C-ring samples made of 65Mn ***,the performance of PAG polymer quenchant is also compared with those of two common quenching solutions:Water and *** cooling in water,the C-ring samples had the largest deformation and 2 times higher than the results obtained when a 10%PAG solution was *** particular,similar levels of deformation on the C-ring samples were observed in both cases of 20%PAG solution and oil as the primary quenching ***,the hardness level measured between the sampled parts quenched in the 20%PAG solution appeared to be more uniform than that obtained from the oil-quenched *** study of the microscopic structure of steel by optical microscopy combined with X-ray diffraction showed that the water hardened sample exhibited cracks and comprised of two phases,martensite and retained *** to the results of Electron Back Scattering Diffraction(EBSD)analysis and backscattering electronic image(BSE),the content of austenite residue in the sample when the sample was cooled in PAG 10 and 20%solution was 3.21%and 4.73%,respectively and smaller than the measurements obtained from oil quenching ***,the 65Mn steel is cooled in 20%PAG solution for high hardness and more evenly distributed than when it is q

关键词： Polyethylene glycol electron backscattering diffraction quenching media cooling rate backscattering electronic image

Thermodynamic Simulation on the Change in Phase for Carburizing Process

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Computers, Materials & Continua 2021年第7期68卷 1129-1145页

作者： anh Tuan Hoang xuan Phuong Nguyen Osamah Ibrahim Khalaf Thi xuan Tran Minh Quang Chau Thi Minh Hao dong Duong Nam Nguyen Ho Chi Minh city University of Technology(HUTECH) HoVietnam Ho Chi Minh city University of Transport Ho Chi Minh cityVietnam Al-Nahrain University Al-Nahrain Nanorenewable Energy Research CenterBaghdadIraq Hanoi University of Science and Technology HanoiVietnam Industrial University of Ho Chi Minh City(IUH) Ho Chi Minh cityVietnam Vietnam Maritime University HaiphongVietnam

The type of technology used to strengthen the surface structure of machine parts,typically by carbon-permeation,has made a great contribution to the mechanical engineering industry because of its outstanding advantages in corrosion resistance and enhanced mechanical and physical ***,carbon permeation is considered as an optimal method of heat treatment through the diffusion of carbon atoms into the surface of alloy *** study presented research results on the thermodynamic calculation and simulation of the carbon permeability *** Fick’s law,the paper calculated the distribution of carbon concentration in the alloy steel after it is absorbed from the surface into the internal of the *** the SYSWELD software,an analysis was performed on the carbon permeability process to determine the distribution of carbon concentrations in 20CrMo steel that was then followed by a detailed analysis of the microstructure of the sample post the carburizing *** to the calculation results,the surface carbon content was 0.9%and steadily decreased into the *** 3 hours,the depth of the absorbent layer was measured at 0.5 mm for both the cylindrical and cubic *** analyzing the phase,the distribution of martensite phases such as ferrite/pearlite and residual austenite was also determined after the carburizing process.

关键词： Carburizing process 20CrMo steel thermodynamic analysis microstructure formation carbon concentration

Synthesis and characterization of core/shell structured nanophosphors CePO_4:Tb@LaPO_4 by solvothermal method

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Journal of Rare Earths 2011年第12期29卷 1147-1151页

作者： Dinh xuan Loc Tran Thi Kim Chi Tran Thu Huong Nguyen Vu Tran Kim anh Wieslaw Strek Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology Institute of Low Temperature and Structure Research Polish Academy of Sciences(PAN) University of Engineering and Technology

Core/shell structured CePO4：Tb（Ⅲ）@LaPO4 and CePOa：Tb（Ⅲ） were successfully synthesized in tris（2-ethylhexyl） phosphate （TEHP） and diethylene glycol （DEG） solvents for comparison of the two techniques in open air and closed reaction vessel. Morphology and crystal structure of the core/shell nanophosphors were determined by using X-ray diffraction （XRD） and transmission electron microscopy （TEM）, which showed that nanophosphors had diameter of about 5-10 nm with the monoclinic monazite phase. The nanophosphors obtained by close vessel procedure showed smaller size, more homogeneity and pure crystallite. The luminescent measurements were done upon the different excitation wavelengths in ultraviolet region and at room temperatm＇e to elucidate the influences of the used solvents and the reaction temperatures. It was found that CePO4：Tb@LaPO4 preparedby the close vessel synthesis showed the intensity of green band of the transfer from 5D4 to 7F5 energy level, which was strongly increased, and the luminescent decay time was 3.2 ms, which was longer than that of naked CePO4：Tb phosphor.

关键词： solvothermal synthesis luminescence CePOn:Tb CePOa:Tb@LaPO4 rare earths

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