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Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate element (CS-MIN3)

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Frontiers of Structural and Civil Engineering 2019年第2期13卷 251-272页

作者： Nhan NGUYEN-MINH Nha tran-VAN Thang BUI-XUAN Trung NGUYEN-THOI Faculty of Applied Science Bach Khoa University (BKU)Ho Chi Minh CityVietnam Faculty of Mathematics and Computer Science Ho Chi Minh City University of Science (HCMUS)Ho Chi Minh CityVietnam Department of Mathematics L ouisiana State UniversityBaton RougeLA 70803USA Division of Computational Mathematics and Engineering Institute of Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Many homogenization models for corrugated panels of different shapes have been proposed. However, there is a lack of investigations for verifying their accuracy and reliability. In addition, in the recent trend of development of smoothed finite element methods, the cell-based smoothed three-node Mindlin plate element (CS-MIN3) based on the first-order shear deformation theory (FSDT) has been proposed and successfully applied to many analyses of plate and shell structures. Thus, this paper further extends the CS-MIN3 by integrating itself with homogenization models to give homogenization methods. In these methods, the equivalent extensional, bending, and transverse shear stiftriess components which constitute the equivalent orthotropic plate models are represented in explicit analytical expressions. Using the results of ANSYS and ABAQUS shell simulations as references, some numerical examples are conducted to verify the accuracy and reliability of the homogenization methods for static analyses of trapezoidally and sinusoidally corrugated panels.

关键词： homogenization corrugated panel asymptotic analysis smoothed finite element method (S-FEM) cell-based smoothed three-node Mindlin plate element (CS-MIN3)

Structure, Plastic Deformation of Polyethylene: A Molecular Dynamics Method

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Advances in Materials Physics and Chemistry 2020年第6期10卷 125-150页

作者： Dung Nguyen Trong Tuan tran Quoc Hue dang Thi Minh Cuong Nguyen Chinh Van Duong Quoc Faculty of Physics Hanoi National University of Education Ha Noi Vietnam Faculty of Basic Science University of Transport Technology Ha Noi Vietnam Faculty of Electrical and Electronics Engineering Thuyloi University Ha Noi Vietnam

This paper studies the influence factors of atoms number (N) at temperature (T) and after annealing time (t) on the structure shape and the plastic deformation of Polyethylene C2H4 (PE) by the Molecular Dynamics (MD) method with Dreading pair interaction, cyclic boundary conditions and plastic deformation of Polyethylene (PE) be done by stretching method according to the z-axis. The results of structure, plastic deformation of PE are analyzed through size (l), the total energy of the system (Etot), shape and associated energy (Ebond), angular binding energy (Eangle), energy Edihedral, interactive energy Vander Walls (Enon-bonding). When increasing N, t leads to the number of structural units of Face-Centred Cubic (FCC), Body-Centered Cubic (BCC) and Hexagonal Close-Packed (HCP) increasing, but Amorphous (Amor) decreases while the angle between the atoms is a constant corresponding to 109.5°. Besides, the length of the link (r) increases from r = 1.529 Å to r = 1.558 Å while the plastic deformation energy of PE gets an enormous change and the bonding angle at 109.27°. The length of the link r = 1.529 Å and the size (l) of the PE material increase from l = 3.7

关键词： Molecular Dynamics Atoms Number Annealing Time Polyethylene Plastic Deformation

Assessment of Water Scarcity Levels in the Srepok River Basin

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Open Journal of Modern Hydrology 2024年第4期14卷 231-249页

作者： Le Van Linh Tu Anh Nguyen Nguyen Anh Duc tran Van Tra Nguyen Thanh Long dang Dinh Duc tran Duc Thinh Nguyen Thi Bich Water Resources Institute Ministry of Natural Resources and Environment Ha Noi Viet Nam Center for Environmental Fluid Dynamics VNU University of Science Ha Noi Viet Nam National Centre for Water Resources Planning and Investigation Ministry of Natural Resources and Environment Ha Noi Viet Nam Institute of Geography Viet Nam Academy of Science and Technology Ha Noi Viet Nam

Water scarcity has become a pressing global issue, worsening food security, hindering economic development, compromising environmental quality, and threatening human health and other fundamental societal needs. Viet Nam is among the countries severely affected by water scarcity. This study comprehensively assesses the extent and scale of water scarcity in the Srepok River Basin, considering the impacts of water resource allocation, balance, and environmental flows. The areas heavily affected by water scarcity include Ea Hleo, Ea Krong Ana, and several Srepok River branches, with water scarcity periods mainly concentrated in February, March, and April. The influence of climate change has increased the extent and level of water scarcity in the river, affecting an estimated 1.4 million people for at least one month and about 1 million for at least three months. The agricultural sector is significantly affected by water scarcity, with water shortages of 50% according to the baseline scenario and over 60% according to climate change scenarios.

关键词： Water Scarcity Level Water Balance Climate Change RCP 4.5 Srepok River Basin

Effect of fly ash and slag on concrete:Properties and emission analyses

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Frontiers of Engineering Management 2019年第3期6卷 395-405页

作者： Vivian W.Y.TAM khoa N.LE Ana Catarina Jorge EVANGELISTA Anthony BUTERA Cuong N.N.tran Ashraf TEARA College of Civil Engineering Shenzhen UniversityShenzhen 518061China Western Sydney University School of ComputingEngineering and MathematicsLocked Bag 1797PenrithNSW 2751Australia

Recycled concrete is a material with the potential to create a sustainable construction ***,recycled concrete presents heterogeneous properties,thereby reducing its applications for some structural purposes and enhancing its application in *** paper provides an insight into a solution in the deformation control for recycled concrete by adding supplementary cementitious materials fly ash and blast furnace *** of this study indicated that the 50%fly ash replacement of Portland cement increased the rupture modulus of the recycled ***,a mixture with over 50%cement replacement by either fly ash or slag or a combination of both exhibited detrimental effect on the compressive strength,rupture modulus,and drying *** combined analysis of environmental impacts and mechanical properties of recycled concrete demonstrated the possibility of optimizing the selection of recycled concrete because the best scenario in this study was obtained with the concrete mixture M8(50%of fly ash+100%recycled coarse aggregate).

关键词： recycled aggregate recycled concrete fly ash and slag

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

Genesis and Quality of Groundwater in the Southeastern Region of Southern Vietnam

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Journal of Environmental Science and Engineering(A) 2017年第6期6卷 277-292页

作者： Chau tran Vinh tran Hong Thai Doan Van Canh dang Due Nhan Nguyen Cao Huan Nguyen Van Nghia Nguyen Hong Hieu Trinh Thi Thu Van Department of Water Resources Management Ministry of Natural Resources and Environment Hanoi 100000 Vietnam National Meteorological and Hydrological Center Hanoi 100000 Viemam Hydrogeology Assoeiation of Vietnam Hanoi 100000 Vietnam Department of Geology Hanoi University of Natural Sciences Hanoi 100000 Vietnam

The origin and quality of groundwater in the Southeastern region （belongs to Southern Plain） were identified by using isotopic techniques and geochemical analysis. Groundwater samples were collected from 7 aquifers： the Holocene, upper Pleistocene, middle Pleistocene, lower Pleistocene, upper Pliocene, middle Pliocene and Miocene aquifers. The water isotopic compositions （82H and 8180） were determined to elucidate the origin and the interaction between surface water and groundwater studies. transit time （age） of the groundwater samples was determined to explain the direction of groundwater flow. The dating techniques included 3H and ^14C isotopes measurement, followed by a correction for the initial ^14C-activity by the ^13C-composition （^13C） in TDIC （Total Dissolved Inorganic Carbon）. Geochemical parameters of the groundwater samples were measured either directly in the field or in the laboratory. The results showed that the groundwater from the Holocene and upper Pleistocene aquifers was most recharged from the local meteorological and hydrological systems, including local precipitation, fiver and reservoirs. Thus, it has short transit time and its stable isotopic composition is spread around the local meteoric waterline and lines for rivers or reservoirs water. The groundwater in the deeper aquifers： middle and lower Pleistocene, and Neogene aquifers has old age up to 22.5 ka BP. Its water seems to be recharged from the areas with an altitude from 600 to 700 m higher to the Neogene deposit layer altitude. The groundwater in the SE SP （South-Eastern Southern Plain） region has a high quality. The water type is Na-Ca-Mg-HCO3 with low content of chloride and TDS （Total Dissolved Solids）. Calcite/dolomite and gypsum dissolution, organic matter decomposition and sequence of red-ox reactions proceeding through different electron acceptors sediment were controlled the chemistry of the groundwater in the study region.

关键词： Water isotopic composition ^14C-dating groundwater South-Eastern Southern Plain region Vietnam.

Assessing and Forecasting Saline Intrusion in theVietnamese Mekong Delta Under the Impact of Upstreamflow and Sea Level Rise

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Journal of Environmental Science and Engineering(B) 2019年第5期8卷 174-185页

作者： tran Xuan Hai Vu Van Nghi Vu Hoang Hung Do Ngoc Tuan dang Thanh Lam Can Thu Van Institute for Science and Technology Innovation Ho Chi Minh City 700000Vietnam University of Science Vietnam National UniversityHo Chi Minh City 700000Vietnam Thuyloi University Ha No 100000Vietnam Southern Institute for Water Resources Planning Ho Chi Minh City 700000Vietnam Ho Chi Minh City University of Natural Resources and Environment Ho Chi Minh City 700000Vietnam

Saline intrusion is a hot issue and has always been of concern in the VMD(Vietnamese Mekong Delta),especially in the context of many changes of impact factors such as upstream flows and SLR(Sea Levels Rise).Vulnerability to changes in the upstream flows and SLR ismust-have reasons for updated and interpreted *** information is used for exploiting of soil and water *** 11 model was successfully applied to assess the saline *** study provided the picture of the saline intrusion in the dry season from January to May in the VMD in the existing situation(2015 and 2016)and the future(2030 and 2050)under the impact of flow at Kratie in various frequencies of 18%,50%and 85%based on the time series of 2001-2016,and SLR according to RCP(Representative Concentration Pathway)4.5 scenario of MONRE(Ministry of Natural Resources and Environment)of Vietnam issued in *** results show that in the year 2015 the ASI(Saline Intrusion Area)in the VMD was relatively low due to moderate tidal level and high Kratie discharge(P=18%).The scenario like the situation in 2016 and in the future ASI increased significantly compared to the 2015 baseline scenario which shows that the VMD is very vulnerable to saline *** on multivariate regression analysis,the study also presented the formulas for the relationship between the ASI of 0.25 g/L,2.5 g/L and 4.0 g/L thresholds and the impact factors such as the average discharge at Kratie and the maximum daily tidal level in East Coast during the dry season from January to *** an adjusted R2 at 0.913-0.974,these formulas are believed to be reliable for predicting ASIs based on the Kratie flow and the East Coast tidal level.

关键词： Saline intrusion sea level rise upstream flow VMD

A novel over-sampling method and its application to miRNA prediction

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Journal of Biomedical Science and Engineering 2013年第2期6卷 236-248页

作者： Xuan Tho dang Osamu Hirose Thammakorn Saethang Vu Anh tran Lan Anh T. Nguyen Tu Kien T. Le Mamoru Kubo Yoichi Yamada Kenji Satou Graduate School of Natural Science and Technology Kanazawa University Kanazawa Japan Institute of Science and Engineering Kanazawa University Kanazawa Japan

MicroRNAs (miRNAs) are short (~22nt) non-coding RNAs that play an indispensable role in gene regulation of many biological processes. Most of current computational, comparative, and non-comparative methods commonly classify human precursor micro- RNA (pre-miRNA) hairpins from both genome pseudo hairpins and other non-coding RNAs (ncRNAs). Although there were a few approaches achieving promising results in applying class imbalance learning methods, this issue has still not solved completely and successfully yet by the existing methods because of imbalanced class distribution in the datasets. For example, SMOTE is a famous and general over-sampling method addressing this problem, however in some cases it cannot improve or sometimes reduces classification performance. Therefore, we developed a novel over-sampling method named incre-mental- SMOTE to distinguish human pre-miRNA hairpins from both genome pseudo hairpins and other ncRNAs. Experimental results on pre-miRNA datasets from Batuwita et al. showed that our method achieved better Sensitivity and G-mean than the control (no over- sampling), SMOTE, and several successsors of modified SMOTE including safe-level-SMOTE and border-line-SMOTE. In addition, we also applied the novel method to five imbalanced benchmark datasets from UCI Machine Learning Repository and achieved improvements in Sensitivity and G-mean. These results suggest that our method outperforms SMOTE and several successors of it in various biomedical classification problems including miRNA classification.

关键词： Imbalanced Dataset Over-Sampling SMOTE miRNA Classification

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水稻4个产量性状的SSR关联分析

南京农业大学学报 2014年第4期37卷 1-8页

作者： tran Thi Thu Giang 党小景刘强明 HOANG Kim Toan EDZESI Wisdom Mawuli 洪德林南京农业大学作物遗传与种质创新国家重点实验室江苏南京210095

为发掘影响水稻产量性状的有利等位变异及其载体材料用于品种产量潜力改良,2011和2012年调查了不同地理来源的540个亚洲栽培稻品种的4个产量性状,鉴定了这540个品种262对SSR标记的基因型,利用STRUCTURE 2.2软件分析了群体结构,运用TASSE... 详细信息

为发掘影响水稻产量性状的有利等位变异及其载体材料用于品种产量潜力改良,2011和2012年调查了不同地理来源的540个亚洲栽培稻品种的4个产量性状,鉴定了这540个品种262对SSR标记的基因型,利用STRUCTURE 2.2软件分析了群体结构,运用TASSEL 2.1软件中的一般线性模型检测了与4个性状显著关联的SSR标记位点。结果表明:540个品种组成的自然群体中单株有效穗数、每穗实粒数、千粒质量和单株籽粒产量的变异系数值2年平均分别为36.73%、29.90%、10.08%和35.21%。自然群体被划分为7个亚群。各亚群内均存在不同程度的连锁不平衡。2年均检测到的与4个性状显著关联的SSR标记位点有30个。其中与单株有效穗数显著关联的有9个,携有RM3533-105等位变异的‘晚芦栗’对增加单株有效穗数效应最大;与每穗实粒数显著关联的有11个,携有RM5746-120等位变异的‘越108’对增加每穗实粒数效应最大;与千粒质量显著关联的有6个,携有RM17-145等位变异的‘宁粳恢338’对增加千粒质量效应最大;与单株籽粒产量显著关联的有4个,携有RM206-245等位变异的‘老来红’对增加单株籽粒产量效应最大。结论:不同地理来源的水稻品种含有控制不同性状的最优等位变异,可用于不同目标性状的改良。

关键词：水稻产量相关性状 SSR分子标记有利等位变异