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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

Prediction of Shear Bond Strength of Asphalt Concrete Pavement Using Machine Learning Models and Grid Search Optimization Technique

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 691-712页

作者： Quynh-Anh Thi Bui Dam Duc Nguyen Hiep van Le Indra Prakash Binh Thai pham Civil Engineering Department University of Transport Technology54 Trieu KhucThanh XuanHanoi100000Vietnam DDG(R)Geological Survey of India Gandhinagar382010India

Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement *** study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Extra Trees(ET),and Light Gradient Boosting Machine(LGBM),to predict SBS based on easily determinable input ***,the Grid Search technique was employed for hyper-parameter tuning of the ML models,and cross-validation and learning curve analysis were used for training the *** models were built on a database of 240 experimental results and three input variables:temperature,normal pressure,and tack coat *** validation was performed using three statistical criteria:the coefficient of determination(R2),the Root Mean Square Error(RMSE),and the mean absolute error(MAE).Additionally,SHAP analysis was also used to validate the importance of the input variables in the prediction of the *** show that these models accurately predict SBS,with LGBM providing outstanding ***(Shapley Additive explanation)analysis for LGBM indicates that temperature is the most influential factor on ***,the proposed ML models can quickly and accurately predict SBS between two layers of asphalt concrete,serving practical applications in flexible pavement structure design.

关键词： Shear bond asphalt pavement grid search optimization machine learning

Cellular models of stress resistance may pave ways to fight neurodegenerative diseases

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Neural Regeneration Research 2025年第9期20卷 2579-2580页

作者： Thu Nguyen Minh pham Christian Behl Institute of Pathobiochemistry University Medical Center of the Johannes Gutenberg UniversityMainzGermany

Alzheimer's disease(AD),the most common form of neurodegeneration,is characterized by selective neuronal vulnerability and brain regionselective neuron *** entorhinal cortex and hippoc,ampal CA1 projection neurons are at greater risk in AD whereas other regions display resistance to ***,the cerebellum,a phylogenetically very old region,is affected only very late in the disease progression.

关键词： cortex resistance Alzheimer

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)

Performance Comparison of Chemically Modified Sugarcane Bagasse for Removing Cd(II) in Water Environment

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Journal of Renewable Materials 2019年第5期7卷 415-428页

作者： manh Khai Nguyen Minh Trang Hoang Thi Thuy pham Bart van der Bruggen Falculty of Environmental Science VNU University of Science334 Nguyen TraiHanoiVietnam Laboratory for Process Engineering for Sustainable Systems Department of Chemical EngineeringKU LeuvenBelgiumCelestijnenlaan 200F3001 LeuvenBelgium

This paper evaluates the adsorption capacity of chemically sugarcane bagasses with sodium hydroxide(SHS),citric acid(CAS),tartaric acid(TAS)and unmodified sugarcane bagasse(SB)for cadmium adsorption in water *** results prove adsorption capacity for Cd(II)increases after chemical modification and the adsorption fits perfectly with the Langmuir *** had the highest maximum adsorption capacity of 45.45 mg/g followed by TAS with 38.46 mg/g and SHS with 29.41 at optimum pH 5.0 and 120 minutes equilibrium time while 1 g SB removed 18.8 mg Cd(II)in the same *** kinetics study of the process followed a pseudo-secondorder rate expression,that indicated a strong interaction between the biosorbents and *** sugarcane bagasse and modified sugarcane bagasse were characterized by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)*** chemical modification was confirmed by the presence of carboxyl and esters groups created at 1,738 *** estimation of acid groups in modified materials shows the enhancement of this group after *** the other hand,desorption studies showed the high leaching of cadmium ion from the biosorbent leading to the efficient reutilization of materials.

关键词： Cadmium chemical modification citric acid sugarcane bagasse

Effect of heating time on structural,morphology,optical,and photocatalytic properties of g-C3N4 nanosheets

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Chinese Physics B 2020年第5期29卷 504-508页

作者： Nguyen manh Hung Le Thi Mai Oanh Lam Thi Hang pham Do Chung pham Thi Duyen Dao Viet Thang Nguyen van Minh Center for Nano Science and Technology Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi100000Vietnam Department of Physics Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi100000Vietnam Faculty of Basic Sciences Hanoi University of Natural Resources and Environment41A Phu Dien RoadNorth Tu LiemHanoi100000Vietnam Hanoi University of Mining and Geology Duc Thang wardNorth Tu Liem DistrictHanoi100000Vietnam Military science Academy 322 Le Trong Tan streetDinh CongHoang MaiHanoi100000Vietnam

Effect of heating time on the structural,morphology,optical,and photocatalytic properties of graphitic carbon nitride(g-C3N4)nanosheets prepared at 550℃in Ar atmosphere is *** investigations are carried out by using x-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier-transform infrared spectroscopy(FTIR),UV-vis absorption,and photoluminescence(PL).At a heating temperature of 550℃,g-C3N4 nanocrystals are formed after 0.5 h and become more orderly as the heating time *** surface area of the g-C3N4 nanosheets significantly increases as the preparation time *** g-C3N4 prepared in 2.5 h shows the highest photocatalytic performance,decomposing completely 10 ppm RhB solution under xenon lamp irradiation for 2.0 h.

关键词： nanosheets photocatalytic heating time Ar atmosphere

New design of single-symbol decodable STBCs for MIMO communication system

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The Journal of China Universities of Posts and Telecommunications 2011年第6期18卷 44-50页

作者： pham van-bien Department of Communication Engineering Nanjing University of Science and Technology

Single-symbol maximum-likelihood （ML） decodable space-time block codes （SSDCs） can achieve a maximal symbol rate of 6/7 for multiple-input multiple-output （MIMO） communication system with five or six transmit antennas by using rate-efficient generalized coordinate interleaved orthogonal designs （RE-GCIODs）. Unfortunately, there are many zero entries in the eodeword matrix of RE-GCIODs. The zero entries result in high peak-to-average power ratio （PAPR） and also impose a severe constraint on hardware implementation. In this paper, for MIMO communication systems with five or six transmit antennas and one receive antenna, a new SSDC is proposed. By combining Alamouti code and orthogonal space-time block code （OSTBC）, desirable properties like RE-GCIODs can be achieved and are derived, including maximal symbol rate up to 6/7, full diversity and single-symbol ML decodability. Moreover, by reducing the number of zero entries in the codeword matrix, the peak-to-average power ratio （PAPR） of our proposed code is lower than RE-GCIODs. Simulation results show that the proposed codes outperform RE-GCIODs under peak power constraint while performing almost same under average power constraint.

关键词： space-time block code (STBC) full diversity MIMO PAPR

New design of no-zero-entry single symbol ML decodable STBCs based on group precoding

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 70-75页

作者： pham van-bien Department of Communication Engineering Nanjing University of Science and Technology

In multiple-input multiple-output （MIMO） systems, space-time block codes （STBCs） from orthogonal designs （ODs） and coordinate interleaved orthogonal designs （CLOD） have been attracting wider attention due to their amenability for fast （single symbol） maximum-likelihood （ML） decoding, and full-rate with full-rank over quasi-static fading channels. However, most of these codes, for transmitting antennas more than 4, have large number of zero entries in their codeword matrix. Due to the zero entries in the design, the transmitting antennas need to be switched on and off imposing severe hardware constraints. To solve this problem, we propose a method to generate a new class of no-zero-entry single symbol maximum likelihood decodable STBCs （NZESSDCs）, which is based on coordinate interleaving and group precoding technique. The ability of the proposed group precoding based NZESSDCs （called G-NZESSDCs） on single symbol ML Decoding and full diversity are analyzed and derived. The performance evaluation is accomplished by numerical simulation and is compared with recently reported NZESSDCs （called C-NZESSDCs）. Compared with C-NZESSDCs, the proposed G-NZESSDCs have same bit-error-rate （BER） performance and better peak-to-average ratio （PAPR） performance.

关键词： space time block code full diversity MIMO

Finite element analysis of functionally graded sandwich plates with porosity via a new hyperbolic shear deformation theory

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Defence Technology（防务技术） 2022年第3期18卷 490-508页

作者： pham van Vinh Le Quang Huy Department of Solid Mechanics Le Quy Don Technical University236 Hoang Quoc VietHanoiViet Nam Institute of Techniques for Special Engineering Le Quy Don Technical University236 Hoang Quoc VietHanoiViet Nam

This study focusses on establishing the finite element model based on a new hyperbolic sheareformation theory to investigate the static bending,free vibration,and buckling of the functionally graded sandwich plates with *** novel sandwich plate consists of one homogenous ceramic core and two different functionally graded face sheets which can be widely applied in many fields of engineering and defence *** discrete governing equations of motion are carried out via Hamilton’s principle and finite element *** computation program is coded in MATLAB software and used to study the mechanical behavior of the functionally graded sandwich plate with *** present finite element algorithm can be employed to study the plates with arbitrary shape and boundary *** obtained results are compared with available results in the literature to confirm the reliability of the present ***,a comprehensive investigation of the effects of several parameters on the bending,free vibration,and buckling response of functionally graded sandwich plates is *** numerical results shows that the distribution of porosity plays significant role on the mechanical behavior of the functionally graded sandwich plates。

关键词： Functionally graded sandwich plates Porous plates Hyperbolic shear deformation theory Bending analysis Free vibration analysis Buckling analysis

Occurrence of microcystins in water,sediment,and aquatic animals in Dau Tieng Reservoir,Vietnam

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Journal of Oceanology and Limnology 2024年第6期42卷 1751-1763页

作者： Thanh Luu pham manh Ha BUI Tan Duc NGUYEN Thanh Son DAO Faculty of Environment and Labour Safety Ton Duc Thang UniversityHo Chi Minh City 700000Vietnam Faculty of Environment Saigon UniversityHo Chi Minh City 700000Vietnam Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention and Guangdong Provincial Key Laboratory of Marine BiotechnologyShantou UniversityShantou 515063China Faculty of Environment and Natural Resources Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam Asian Center for Water Research(Centre Asiatique de Recherchesur l’Eau CARE)Ho Chi Minh City University of Technology(HCMUT)Vietnam National UniversityHo Chi Minh City 700000Vietnam

This study investigates the variations of microcystins(MCs)in water,cyanobacterial blooms,sediment,and aquatic organisms collected from the Dau Tieng Reservoir(DTR).*** liquid chromatography(HPLC)was employed to measure MC concentrations in various target *** indicate that Microcystis *** as the primary MC producer in the *** average concentrations of analyzed MCs in surface water ranged from 1.10 to 5.54μg/L,temporally and *** sediment,average concentrations varied from 0.15 to 1.13μg/g wet weight(WW)temporally and from 0.41 to 0.72μg/g WW *** were detected in different organs of fish species(Oreochromis *** Labiobarbus sp.)and in the entire soft tissues of bivalve(Corbicula sp.)and gastropod(Assiminea sp.).The highest observed MC concentration in July was 0.83±0.22μg/g WW in the intestines of fish Oreochromis *** presence of MCs in grass shrimp Palaemonetes *** observed solely in June,reaching a concentration of 0.28±0.19μg/g *** is the first report of MC accumulation in the grass shrimp Palaemonetes *** field *** the bivalve Corbicula sp.,the presence of analyzed MCs was consistent throughout the study period,except for March and September,with the highest concentrations in July at 0.77±0.1μg/g *** correlation analysis revealed significant positive correlations between MCs in water and sediment with MC concentrations in aquatic animals,indicating the potential transfer of MCs across different trophic *** estimated daily intake values for analyzed MCs indicate that fish collected from the DTR are considered safe for consumption,as long as only the edible organs,such as the muscle,are ***,bivalves or gastropods collected from the DTR are not safe for human *** study underscored the importance of monitoring MC accumulation in aquatic animals used as food to mitigate adverse effects on human health.

关键词： aquatic animal bioaccumulation cyanotoxin health risk toxic cyanobacteria