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Frontiers of Structural and Civil Engineering 2024年第4期18卷 551-567页

作者： dinh-Nhat TRUONG Van-Lan TO Gia toai TRUONG Hyoun-Seung JANG Department of Civil Engineering University of Architecture Ho Chi Minh CityHo Chi Minh City 700000Vietnam Faculty of Civil Engineering and Technology Dong A UniversityDa Nang City 550000Vietnam School of Architecture Seoul National University of Science and TechnologySeoul 01811Republic of Korea

Reinforced concrete(RC)flat slabs,a popular choice in construction due to their flexibility,are susceptible to sudden and brittle punching shear *** design methods often exhibit significant bias and *** estimation of punching shear strength in RC flat slabs is crucial for effective concrete structure design and *** study introduces a novel computation method,the jellyfish-least square support vector machine(JS-LSSVR)hybrid model,to predict punching shear *** combining machine learning(LSSVR)with jellyfish swarm(JS)intelligence,this hybrid model ensures precise and reliable *** model’s development utilizes a real-world experimental data *** with seven established optimizers,including artificial bee colony(ABC),differential evolution(DE),genetic algorithm(GA),and others,as well as existing machine learning(ML)-based models and design codes,validates the superiority of the JS-LSSVR hybrid *** innovative approach significantly enhances prediction accuracy,providing valuable support for civil engineers in estimating RC flat slab punching shear strength.

关键词： punching shear strength reinforced concrete flat slabs machine learning jellyfish search support vector machine

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

Application of machine learning technique for predicting and evaluating chloride ingress in concrete

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Frontiers of Structural and Civil Engineering 2022年第9期16卷 1153-1169页

作者： Van Quan TRAN Van Loi GIAP dinh Phien vu Riya Catherine GEORGE Lanh Si HO Department of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Civil and Environmental Engineering Program Graduate School of Advanced Science and EngineeringHiroshima UniversityHiroshima 739-8527Japan

The degradation of concrete structure in the marine environment is often related to chloride-induced corrosion of reinforcement ***,the chloride concentration in concrete is a vital parameter for estimating the corrosion level of reinforcement *** research aims at predicting the chloride content in concrete using three hybrid models of gradient boosting(GB),artificial neural network(ANN),and random forest(RF)in combination with particle swarm optimization(PSO).The input variables for modeling include exposure condition,water/binder ratio(W/B),cement content,silica fume,time exposure,and depth of *** results indicate that three models performed well with high accuracy of prediction(R2⩾0.90).Among three hybrid models,the model using GB_PSO achieved the highest prediction accuracy(R2=0.9551,RMSE=0.0327,and MAE=0.0181).Based on the results of sensitivity analysis using SHapley Additive exPlanation(SHAP)and partial dependence plots 1D(PDP-1D),it was found that the exposure condition and depth of measurement were the two most vital variables affecting the prediction of chloride *** the number of different exposure conditions is larger than two,the exposure significantly impacted the chloride content of concrete because the chloride ion ingress is affected by both chemical and physical *** study provides an insight into the evaluation and prediction of the chloride content of concrete in the marine environment.

关键词： gradient boosting random forest chloride content concrete sensitivity analysis

Eye Strain Detection During Online Learning

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Intelligent Automation & Soft Computing 2023年第3期35卷 3517-3530页

作者： Le Quang Thao Duong Duc Cuong vu Manh Hung Le Thanh Vinh Doan Trong Nghia dinh Ha Hai Nguyen Nhan Nhi Faculty of Physics VNU University of ScienceHanoi100000Vietnam University of Science Vietnam National UniversityHanoi100000Vietnam VNU-HUS High School for Gifted StudentsHanoi100000Vietnam Hanoi-Amsterdam High School for the Gifted Hanoi100000Vietnam

The recent outbreak of the coronavirus disease of 2019(Covid-19)has been causing many disruptions among the education systems worldwide,most of them due to the abrupt transition to online *** sudden upsurge in digital electronic devices usage,namely personal computers,laptops,tablets and smart-phones is unprecedented,which leads to a new wave of both mental and physical health problems among students,for example eye-related *** overexpo-sure to electronic devices,extended screen time usage and lack of outdoor sun-light have put a consequential strain on the student’s ophthalmic health because of their young age and a relative lack of responsibility on their own *** to take appropriate external measures to mitigate the negative effects of this pro-cess could lead to common ophthalmic illnesses such as myopia or more serious *** remedy this situation,we propose a software solution that is able to track and capture images of its users’eyes to detect symptoms of eye illnesses while simultaneously giving them warnings and even offering *** meet the requirements of a small and light model that is operable on low-end devices without information loss,we optimized the original MobileNetV2 model with depth-wise separable convolutions by altering the parameters in the last layers with an aim to minimize the resizing of the input image and obtained a new model which we call *** with applying the knowledge distillation tech-nique and ResNet-18 as a teacher model to train the student model,we have suc-cessfully increased the accuracy of the EyeNet model up to 87.16%and support the development of a model compatible with embedded systems with limited computing power,accessible to all students.

关键词： Digital eye strain Covid-19 online study knowledge distillation eye care EyeNet

Propagation Path Loss Models at 28 GHz Using K-Nearest Neighbor Algorithm

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通讯和计算机（中英文版） 2022年第1期19卷 1-8页

作者： vu Thanh Quang dinh Van Linh To Thi Thao Hanoi University of Science and Technology No.1 Dai Co Viet roadHanoiVietnam Academy of Cryptography Techniques 141 Chien Thang RoadHanoiVietnam Post and Telecommunications Institute HanoiVietnamKm 10Nguyen Trai RoadHanoiVietnam

In this paper,we develop and apply K-Nearest Neighbor algorithm to propagation pathloss *** path loss models present the dependency of attenuation value on distance using machine learning algorithms based on the experimental *** algorithm is performed by choosing k nearest points and training dataset to find the optimal k *** proposed method is applied to impove and adjust pathloss model at 28 GHz in Keangnam area,Hanoi,*** experiments in both line-of-sight and non-line-of-sight scenarios used many combinations of transmit and receive antennas at different transmit antenna heights and random locations of receive antenna have been carried out using Wireless Insite *** results have been compared with 3GPP and NYU Wireless Path Loss Models in order to verify the performance of the proposed approach.

关键词： K-nearest neighbor regression 5G millimeter waves path loss

Genetic diversity in two threatened species in Vietnam:Taxus chinensis and Taxus wallichiana

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Journal of Forestry Research 2017年第2期28卷 265-272页

作者： dinh Duy vu Thi Tuyet Xuan Bui Minh Tam Nguyen dinh Giap vu Minh Duc Nguyen Van Thang Bui Xiaohua Huang Yi Zhang College of Forestry Northwest A&F UniversityYangling 712100ShaanxiPeople's Republic of China Vietnam National Museum of Nature Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Ecology and Biological Resource(VAST) 18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Natural Products Chemistry(VAST) 18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Forest Biotechnology Vietnam Forestry UniversityXuan MaiChuong MyHanoiVietnam

Taxus chinensis and T. wallichiana in have been threatened in their distribution areas in recent decades because of their over-exploitation and reduction and destruction of native habitats. Determining the genetic diversity in populations of the two species will provide guidelines for their protection and preservation. Two hundred and fifteen trees from six populations of T. chinensis and150 sampled trees of T. wallichiana were sampled. Six microsatellite primer pairs selected from 16 primer pairs were used to investigate genetic variation at the population and species levels. Five yielded polymorphic alleles, and among the 13 putative alleles amplified, 11 were polymorphic（accounting for 76.33 %）.Shannon＇s information index（I） and percentage of polymorphic bands（PPB）（I = 0.202 and PPB = 67.22 % for T. chinensis; I = 0.217 and PPB = 65.03 % for T. wallichiana）. Both species had low levels of genetic diversity（mean Ho= 0.107, He= 0.121 for T. chinensis; Ho= 0.095, He= 0.109 for T. wallichiana）. Genetic differentiation among populations was higher（FST= 0.189） for T. chinensis and lower（0.156） for ***, indicating limited gene flow（Nm） among populations for T. chinensis（0.68） and T. wallichiana（0.65）.Variation among individuals of T. chinensis was 63.59 and73.12 % for T. wallichiana. Thus, the threatened status of the two conifers is related to a lack of genetic diversity. All populations are isolated in small forest remnants. An ex situ conservation site should be established with a new population for these species that comprises all the genetic groups for the best chance to improve their fitness under environmental stresses.

关键词： Taxus populations alleles polymorphic microsatellite Vietnam primer accounting putative destruction

Genetic diversity and conservation of two threatened dipterocarps(Dipterocarpaceae) in southeast Vietnam

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Journal of Forestry Research 2019年第5期30卷 1823-1831页

作者： dinh-Duy vu Thi Tuyet-Xuan Bui Minh-Duc Nguyen Syed Noor Muhammad Shah dinh-Giap vu Yi Zhang Minh-Tam Nguyen Xiao-Hua Huang College of Forestry Northwest A&F UniversityYanglingShaanxi 712100People’s Republic of China Vietnam National Museum of Nature Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Ecology and Biological Resource Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Department of Horticulture Faculty of AgricultureGomal UniversityDera Ismail KhanPakistan Institute of Natural Products Chemistry Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam

Two threatened dipterocarp species,Dipterocarpus costatus and Dipterocarpus alatus are well-known endangered species in lowland forests of southeastern Vietnam,primarily from habitat loss and over-exploitation of their *** develop conservation strategies for these species,we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of *** and three of ***,representing the natural range of dipterocarps in Southeast *** indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for *** and 0.152 for *** of bottleneck tests indicated a reduction in population size of both species(P>0.05).Genetic differentiation among populations was high(FST=0.347 for *** and 0.274 for ***),indicating limited gene flow(Nm=0.662 for *** and 0.47 for ***)and isolated populations related to geographical *** of molecular variance showed high genetic variation within populations(72.92%for *** and 60.81%for ***)compared to among *** analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical *** results will provide a platform for the conservation,management and restoration of these species.

关键词： Dipterocarps Genetic conservation Gene diversity SSR primers

Evaluation of Interaction between Surface Water and Groundwater in the South of Hanoi City by Stable Isotope Technique

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Journal of Environmental Protection 2022年第11期13卷 870-880页

作者： Vo Thi Anh Tran Khanh Minh Ha Lan Anh Mai dinh Kien vu Hoai Dang Duc Nhan Institute for Nuclear Science and Technology Hanoi Vietnam

The δ18O and δ2H stable isotope techniques for studying properties of groundwater and surface help us to understand more clearly about the distribution and movement of groundwater in the South of Hanoi area. There were 68 water samples from the studying area and analyzed by a Liquid Water Isotope Analyzer (LWIA-24D). The stable isotope values of the groundwater from Pleistocene aquifers were range from -3.21‰ to -9.55‰ δ18O and -35.32‰ to -67.44‰ δ2H;rainwater from -8.18‰ to -4.13‰ δ18O and -61.19‰ to -17.93‰ δ2H;Red river water from -7.51‰ to -5.29‰ δ18O and -51.60‰ to -38.99‰ δ2H. Based on stable isotope characteristics, the results show that there was a relationship between surface water and groundwater in the South of Hanoi city. It is that groundwater recharges for river water in the dry season with 74%, and in the rainfall season groundwater is recharged from river with 87%.

关键词： Stable Isotopes Groundwater Surface Water River Water Precipitation Recharge

Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

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Rice science 2018年第1期25卷 52-56页

作者： Hue Thi NGUYEN Quang Hong vu Tan Van MAI Thu Thi NGUYEN Lam Duc vu Tung Thanh NGUYEN Long Viet NGUYEN Hien Thu Thi vu Hue Thi NONG Trung Nguyen dinh Nakano TOSHITSUGU Liet Van vu Crop Research and Development Institute Vietnam National University of Agriculture Trau Qui Gia Lam Hanoi 10000 Vietnam Faculty of Agronomy Vietnam National University of Agriculture Trau Qui Gia Lam Hanoi 10000 Vietnam Faculty of Biotechnology Vietnam National University of Agriculture Trau Qui Gia Lam Hanoi 10000 Vietnam Faculty of Land Management Vietnam National University of Agriculture Trau Qui Gia Lam Hanoi 10000 Vietnam Japan International Cooperation Agency 16 Phan Chu Trinh Hoan Kiem Hanoi 10000 Vietnam

Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient ***21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC_3F_3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC_3F_3 5.***.5.1, BC_3F_3 5.***.5.12, BC_3F_3 8.***.6.44, BC_3F_3 9.***.4.1 and BC_3F_3 9.***.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

关键词： rice backcrossing bacterial leaf blight marker-assisted selection

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