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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

Tungsten-based nanocatalysts with different structures for visible light responsive photocatalytic degradation of bisphenol A

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Journal of Environmental Sciences 2024年第5期139卷 569-588页

作者： Hai Bang Truong thi Thu Loan Doan Nguyen Tien Hoang Nguyen van Tam Minh Kim Nguyen Le Gia Trung Jin Seog Gwag Nguyen Tien tran Optical Materials Research Group Science and Technology Advanced InstituteVan Lang UniversityHo Chi Minh CityViet Nam Faculty of Applied Technology School of TechnologyVan Lang UniversityHo Chi Minh CityViet Nam The University of Da Nang University of Science and Technology54 Nguyen Luong BangDa NangViet Nam The University of Da Nang University of Science and Education459 Ton Duc Thang St.Lien ChieuDa Nang 550000Viet Nam Institute of Veterinary Science and Technology 31ha zoneTrau QuyGia LamHa Noi 12400Viet Nam Department of Physics Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea Center for Advanced Chemistry Institute of Research and DevelopmentDuy Tan University03 Quang TrungDa Nang 550000Viet Nam Faculty of Natural Sciences Duy Tan University03 Quang TrungDa Nang 550000Viet Nam

Environmental pollution,such as water contamination,is a critical issue that must be absolutely ***,three different morphologies of tungsten-based photocatalysts(WO_(3)nanorods,WO_(3)/WS_(2)nanobricks,WO_(3)/WS_(2)nanorods)are made using a simple hydrothermal method by changing the solvents(H_(2)O,DMF,aqueous HCl solution).The as-prepared nanocatalysts have excellent thermal stability,large porosity,and high *** results show all materials have good photocatalytic activity in aqueous media,with WO_(3)/WS_(2)nanorods(NRs)having the best activity in the photodegradation of bisphenol A(BPA)under visible-light *** may originate from increased migration of charge carriers and effective prevention of electron–hole recombination in WO_(3)/WS_(2)NRs,whereby this photocatalyst is able to generate more reactive·OH and·O_(2)^(–)species,leading to greater photocatalytic *** 99.6% of BPA is photodegraded within 60 min when using 1.5 g/L WO_(3)/WS_(2)NRs and 5.0 mg/L BPA at pH ***,the optimal conditions(pH,catalyst dosage,initial BPA concentration)for WO_(3)/WS_(2)NRs are also elaborately *** rod-like heterostructures are expressed as potential catalysts with excellent photostability,efficient reusability,and highly active effectivity in different types of *** particular,the removal efficiency of BPA by WO_(3)/WS_(2)NRs reduces by only 1.5% after five recycling runs and even reaches 89.1%in contaminated lake *** study provides promising insights for the nearly complete removal of BPA from wastewater or different water resources,which is advantageous to various applications in environmental remediation.

关键词： Photodegradation Bisphenol A Tungsten-based nanocatalyst Structure Nanorod

Assessment of Livelihood Vulnerability to Drought: A Case Study in Dak Nong Province, Vietnam

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International Journal of Disaster Risk Science 2019年第4期10卷 604-615页

作者： Nguyen thi Thanh Thao Dao Nguyen Khoi tran Thanh Xuan Bernard Tychon Universite de Liege 6700 ArlonBelgium Institute for Environmental Science Engineeringand ManagementIndustrial University of Ho Chi Minh CityHo Chi Minh CityVietnam Institute of Research and Development Duy Tan UniversityDa NangVietnam Faculty of Environment University of ScienceVietnam National University Ho Chi Minh CityHo Chi Minh CityVietnam NTT Institute of Hi-Technology Nguyen Tat Thanh UniversityHo Chi Minh CityVietnam

In recent years,droughts have strongly affected the Central Highlands of Vietnam and have resulted in crop damage,yield decline,and serious water *** study investigated the livelihood vulnerability of five communities of farmers who are exposed to droughts in one of the more vulnerable regions of Vietnam—Dak Nong Province.A survey of 250 households was conducted in the five communities to collect data on the region’s sociodemographic profile,livelihood systems,social networks,health status,food and water security,drought conditions,and climate *** were aggregated using a livelihood vulnerability index and the IPCC vulnerability *** survey results indicate that Quang Phu community is the most vulnerable of the study’s communities,followed by Nam N’dir,Dak Nang,Duc Xuyen,and Dak D’ro in descending order of *** availability and livelihood strategies are the most important variables in determining the vulnerability of the five surveyed *** order to reduce vulnerability to droughts,water management practices and livelihood diversification in farming and nonfarming activities are recommended for the study area.

关键词： Agricultural drought Livelihood vulnerability Vietnam Vulnerability indicators

Impact of chosen force fields and applied load on thin film lubrication

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Friction 2021年第5期9卷 1259-1274页

作者： thi D.TA Hien D.TA Kiet A.TIEU Bach H.tran School of Mechanical MaterialsMechatronicsand Biomedical EngineeringUniversity of WollongongNSW 2522Australia Ho Chi Minh City University of Technology and Education Ho Chi Minh City 800010Vietnam

The rapid development of molecular dynamics(MD)simulations,as well as classical and reactive atomic potentials,has enabled tribologists to gain new insights into lubrication performance at the fundamental ***,the impact of adopted potentials on the rheological properties and tribological performance of hydrocarbons has not been researched *** extensive study analyzed the effects of surface structure,applied load,and force field(FF)on the thin film lubrication of *** lubricant film became more solid‐like as the applied load *** particular,with increasing applied load,there was an increase in the velocity slip,shear viscosity,and *** degree of ordering structure also changed with the applied load but rather *** was also significantly dependent on the surface *** chosen FFs significantly influenced the lubrication performance,rheological properties,and molecular *** adaptive intermolecular reactive empirical bond order(AIREBO)potential resulted in more significant liquid‐like behaviors,and the smallest velocity slip,degree of ordering structure,and shear stress were compared using the optimized potential for liquid simulations of united atoms(OPLS‐UAs),condensed‐phase optimized molecular potential for atomic simulation studies(COMPASS),and ***,classical potentials,such as OPLS‐UA and COMPASS,exhibit more solid‐like behavior than reactive potentials ***,owing to the solid‐like behavior,the lubricant temperatures obtained from OPLS‐UA and COMPASS were much lower than those obtained from AIREBO and *** increase in shear stress,as well as the decrease in velocity slip with an increase in the surface potential parameterζ,remained conserved for all chosen FFs,thus indicating that the proposed surface potential parameterζfor the COMPASS FF can be verified for a wide range of atomic models.

关键词： molecular dynamics simulation force fields applied load tribofilm hydrocarbon

Enhancing soil water holding capacity and provision of a potassium source via optimization of the pyrolysis of bamboo biochar

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Biochar 2021年第1期3卷 51-61页

作者： tran thi Thu Hien Toshiki Tsubota Tomoyuki Taniguchi Yoshiyuki Shinogi Laboratory of Irrigation and Water Management Faculty of AgricultureKyushu UniversityFukuoka 8130395Japan Agricultural Science Institute of Northern Central Vietnam Vietnam Academy of Agricultural SciencesVinhNghe An 44000Vietnam Department of Materials Science Faculty of EngineeringKyushu Institute of TechnologyKitakyushu 8048550Japan West No.5 Building 744 MotookaNishi‑WardFukuoka 8190395Japan

Rapid expansion of cultivated bamboo negatively impacts on biodiversity and soil microbial *** such,it is important to properly manage and use bamboo to prevent and control such *** study focuses on optimizing pyrolysis conditions to produce bamboo biochar for agricultural soil amendment,particularly soil potassium(K)and water holding *** chips were pyrolyzed under nitrogen gas at 400,600,and 800℃ for 1 and 2 h of retention.A total of six biochar products were created:400-1(i.e.,400℃ in 1 h),400-2,600-1,600-2,800-1,and *** 600℃ bamboo biochar products were observed to have the greatest potential in increasing soil K and water holding *** 600-1 product had the highest potassium content(4.87%),with a water holding capacity of 3.73 g g^(−1),while the 600-2 product had the second-highest potassium content(4.13%)and the highest water holding capacity(4.21 g g^(−1))and cation exchange *** K release in 600℃ products was larger and slower than that of the 400℃ and 800℃ products,*** results also indicated that the physicochemical characteristics of bamboo biochar,such as yield,pH,surface area,water holding capacity,and K content,were significantly impacted by temperature,retention time,or a combination of these *** outcomes from this study are a valuable reference for bamboo biochar production targeting agricultural soil amendment,particularly when it is directed at increasing soil K and water holding capacity.

关键词： Bamboo biochar Temperature Retention time Potassium Water holding capacity Cation exchange capacity

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

COVID-19 vaccination intention among healthcare workers in Vietnam

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Asian Pacific Journal of Tropical Medicine 2021年第4期14卷 159-164页

作者： Giao Huynh thien Thuan tran Han thi Ngoc Nguyen Le An Pham Faculty of Public Health University of Medicine and Pharmacy at Ho Chi Minh CityHo Chi Minh CityVietnam Infection Control Department University Medical Center Ho Chi Minh CityHo Chi Minh CityVietnam Family Medicine Training Center University of Medicine and Pharmacy at Ho Chi Minh CityHo Chi Minh CityVietnam

Objective:To assess the acceptance of coronavirus disease(COVID-19)vaccine among healthcare workers at two general hospitals in Vietnam when it is ***:A cross-sectional study was conducted using a convenience sampling from January to February 2021 among 410 healthcare workers at two general hospitals in Vietnam via a selfadministered questionnaire.A multivariable regression analysis was performed to determine predictors of vaccine acceptance including the demographic factors,COVID-19 knowledge,and vaccine beliefs based on the domains of Health Belief ***:Among 410 healthcare workers,76.10%showed vaccination *** of acceptance were determined that the group reporting as“vaccine acceptance”was more likely to be positive towards the perceived susceptibility and severity of COVID-19(OR 2.45;95%CI 1.48-4.06,Pvant interv

关键词： Acceptance COVID-19 Healthcare workers Intention SARS-CoV-2 Vaccination

Attribute Reduction on Decision Tables Based on Hausdorff Topology

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Computers, Materials & Continua 2024年第11期81卷 3097-3124页

作者： Nguyen Long Giang tran Thanh Dai Le Hoang Son tran thi Ngan Nguyen Nhu Son Cu Nguyen Giap Institute of Information Technology Vietnam Academy of Science and TechnologyHanoi10000Vietnam Faculty of Information Technology University of Economics-Technology for IndustriesHanoi10000Vietnam VNU Information Technology Institute Vietnam National UniversityHanoi10000Vietnam International School Vietnam National UniversityHanoi10000Vietnam Center of Science and Technology Research and Development Thuongmai UniversityHanoi10000Vietnam

Attribute reduction through the combined approach of Rough Sets(RS)and algebraic topology is an open research topic with significant potential for *** research works have introduced a strong relationship between RS and topology spaces for the attribute reduction ***,the mentioned recent methods followed a strategy to construct a new measure for attribute ***,the strategy for searching for the reduct is still to select each attribute and gradually add it to the ***,those methods tended to be inefficient for high-dimensional *** overcome these challenges,we use the separability property of Hausdorff topology to quickly identify distinguishable attributes,this approach significantly reduces the time for the attribute filtering stage of the *** addition,we propose the concept of Hausdorff topological homomorphism to construct candidate reducts,this method significantly reduces the number of candidate reducts for the wrapper stage of the *** are the two main stages that have the most effect on reducing computing time for the attribute reduction of the proposed algorithm,which we call the Cluster Filter Wrapper algorithm based on Hausdorff *** validation on the UCI Machine Learning Repository Data shows that the proposed method achieves efficiency in both the execution time and the size of the reduct.

关键词： Hausdorff topology rough sets topology from rough sets attribute reduction

Contributions of Rotation,Expansion and Line Broadening to the Morphology and Kinematics of the Inner CSE of Oxygen-rich AGB Star R Hya

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Research in Astronomy and Astrophysics 2023年第1期23卷 40-47页

作者： Pham Tuyet Nhung Do thi Hoai Pierre Darriulat Pham Ngoc Diep Nguyen Bich Ngoc tran thi Thai Pham Tuan-Anh Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa NoiVietnam

We use archival ALMA observations of the CO(2-1)and SiO(5-4)molecular line emissions of AGB star R Hya to illustrate the relative contributions of rotation,expansion and line broadening to the morphology and kinematics of the circumstellar envelope(CSE)within some~70 au(~0."5)from the centre of the *** give evidence for rotation and important line broadening to dominate the inner region,within~14 au(~100 mas)from the centre of the *** former is about an axis that projects a few degrees west of north and has a projected rotation velocity of a few km s^(-1).The latter occurs within some 7-14 au(50-100 mas)from the centre of the star,with the line width reaching two to three times its value outside this *** suggest that it is caused by shocks induced by stellar pulsations and convective cell *** show the importance of properly accounting for the observed line broadening when discussing rotation and evaluating the radial dependence of the rotation velocity.

关键词： stars AGB and post-AGB-(stars:)circumstellar matter-radio lines