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Novel Time Series Bagging Based Hybrid Models for Predicting Historical Water Levels in the Mekong Delta Region, Vietnam

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Computer Modeling in Engineering & Sciences 2022年第6期131卷 1431-1449页

作者： nguyen Thanh Hoan nguyen Van Dung Ho Le thu Hoa thuy Quynh Nadhir Al-Ansari Tran Van Phong Phan Trong Trinh Dam Duc nguyen Hiep Van Le Hanh Bich Thi nguyen Mahdis Amiri Indra Prakash Binh Thai pham Institute of Geography Vietnam Academy of Science and TechnologyHanoi10000Viet Nam Department of Civil Environmental and Natural Resources EngineeringLulea University of TechnologyLulea97187Sweden Institute of Geological Sciences Vietnam Academy of Science and Technology(VAST)Dong DaHanoi10000Viet Nam University of Transport Technology Thanh XuanHa Noi10000Viet Nam Department of Watershed&Arid Zone Management Gorgan University of Agricultural Sciences&Natural ResourcesGorgan***Iran DDG(R)Geological Survey of India Gandhinagar382010India

Water level predictions in the river,lake and delta play an important role in flood *** year Mekong River delta of Vietnam is experiencing flood due to heavy monsoon rains and high *** subsidence may also aggravate flooding problems in this ***,accurate predictions of water levels in this region are very important to forewarn the people and authorities for taking timely adequate remedial measures to prevent losses of life and *** are so many methods available to predict the water levels based on historical data but nowadays Machine Learning(ML)methods are considered the best tool for accurate *** this study,we have used surface water level data of 18 water level measurement stations of the Mekong River delta from 2000 to 2018 to build novel time-series Bagging based hybrid ML models namely:Bagging(RF),Bagging(SOM)and Bagging(M5P)to predict historical water levels in the study *** of the Bagging-based hybrid models were compared with Reduced Error Pruning Trees(REPT),which is a benchmark ML *** data of 19 years period was divided into 70:30 ratio for the *** data of the period 1/2000 to 5/2013(which is about 70%of total data)was used for the training and for the period 5/2013 to 12/2018(which is about 30%of total data)was used for testing(validating)the *** of the models was evaluated using standard statistical measures:Coefficient of Determination(R2),Root Mean Square Error(RMSE)and Mean Absolute Error(MAE).Results show that the performance of all the developed models is good(R2>0.9)for the prediction of water levels in the study ***,the Bagging-based hybrid models are slightly better than another model such as ***,these Bagging-based hybrid time series models can be used for predicting water levels at Mekong data.

关键词： Computational techniques bagging water level time series algorithms

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Deep learning-based signal processing for evaluating energy dispersal in bridge structures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第8期22卷 672-680页

作者： Nhi NGO-KIEU Thao nguyen-DA Toan pham-BAO Tam nguyen-NHAT Hung nguyen-XUAN Laboratory of Applied Mechanics(LAM) Ho Chi Minh City Univer-sity of Technology(HCMUT)Ho Chi Minh CityVietnam Vietnam National University Ho Chi minh City Ho Chi Minh CityVietnam Ho Chi minh City Department of Transportation Ho Chi Minh CityVietnam CIRTECH Institute Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityVietnam

In this paper,we use deep learning to investigate a loss factor function(LF)for measuring energy dispersal in bridge structures in Ho Chi minh City,*** LF is calculated from the power spectral density(PSD)of random vi... 详细信息

关键词： bridge energy dispersal

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Free vibration analysis of functionally graded porous curved nanobeams on elastic foundation in hygro-thermo-magnetic environment

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Frontiers of Structural and Civil Engineering 2023年第4期17卷 584-605页

作者： Quoc-Hoa pham Parviz MALEKZADEH Van Ke TRAN Trung nguyen-THOI Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam Department of Mechanical Engineering Persian Gulf UniversityBushehr ***Iran Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi 100000Vietnam Laboratory for Applied and Industrial Mathematics Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh City 700000Vietnam Faculty of Mechanical-Electrical and Computer Engineering School of TechnologyVan Lang UniversityHo Chi Minh City 700000Vietnam Bualuang ASEAN Chair Professor Thammasat School of EngineeringThammasat UniversityPathumtani 12120Thailand

Herein,a two-node beam element enriched based on the Lagrange and Hermite interpolation function is proposed to solve the governing equation of a functionally graded porous(FGP)curved nanobeam on an elastic foundation in a hygro–thermo–magnetic *** material properties of curved nanobeams change continuously along the thickness via a power-law distribution,and the porosity distributions are described by an uneven porosity *** effects of magnetic fields,temperature,and moisture on the curved nanobeam are assumed to result in axial loads and not affect the mechanical properties of the *** equilibrium equations of the curved nanobeam are derived using Hamilton’s principle based on various beam theories,including the classical theory,first-order shear deformation theory,and higher-order shear deformation theory,and the nonlocal elasticity *** accuracy of the proposed method is verified by comparing the results obtained with those of previous reliable ***,the effects of different parameters on the free vibration behavior of the FGP curved nanobeams are investigated comprehensively.

关键词： functionally graded porous material curved nanobeam hygro-thermo-magnetic enriched finite element method

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Infectious etiopathogenesis of Crohn's disease

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World Journal of Gastroenterology 2014年第34期20卷 12102-12117页

作者： Jessica Carriere Arlette Darfeuille-Michaud Hang Thi thu nguyen Clermont Universite M2iSHUMR 1071 Inserm University of Auvergne 63001 Clermont-FerrandFrance INRA USC 2018 63000 Clermont-FerrandFrance Centre Hospitalier Universitaire 63000 Clermont-FerrandFrance

Important advances during the last decade have been made in understanding the complex etiopathogenesis of Crohn’s disease(CD).While many gaps in our knowledge still exist,it has been suggested that the etiology of CD is multifactorial including genetic,environmental and infectious *** most widely accepted theory states that CD is caused by an aggressive immune response to infectious agents in genetically predisposed *** rise of genome-wide association studies allowed the identification of loci and genetic variants in several components of host innate and adaptive immune responses to microorganisms in the gut,highlighting an implication of intestinal microbiota in CD ***,numerous independent studies reported a dysbiosis,i.e.,a modification of intestinal microbiota composition,with an imbalance between the abundance of beneficial and harmful *** microorganisms including viruses,yeasts,fungi and bacteria have been postulated as potential CD pathogens,based on epidemiological,clinicopathological,genetic and experimental evidence,their precise role in this disease is not clearly *** review summarizes the current knowledge of the infectious agents associated with an increased risk of developing *** approaches to modulate the intestinal dysbiosis and to target the putative CD-associated pathogens,as well as their potential mechanisms of action are also discussed.

关键词： Crohn's disease Intestinal microbiota Dysbiosis Adherent-invasive Escherichia coli Probiotics Antibiotics Fecal microbiota transplantation

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Spherical Fuzzy WASPAS-based Entropy Objective Weighting for International Payment Method Selection

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Computers, Materials & Continua 2022年第7期72卷 2055-2075页

作者： Phi-Hung nguyen Thanh-Tuan Dang Kim-Anh nguyen Hong-Anh pham Faculty of Business FPT UniversityHanoi100000Vietnam Department of Business Management National Taipei University of TechnologyTaipei1068Taiwan Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan

In international trade,exporters prefer to receive payments as quickly as possible,and importers want to make payments as late as *** this respect,the payment field,an essential condition for trade transactions,also represents the positions of exporters and importers *** addition,there are many cases in which various variables must be considered rather than only one specific variable representatively affecting payment,particularly in the case of import-export Small and Medium-Sized Enterprises(SMEs)from emerging countries.A selection of proper payment methods can be categorized as a Multi-Criteria Decision-Making(MCDM)***,this study aims to propose a novel and efficient Spherical Fuzzy Weighted Aggregated Sum Product Assessment based Entropy Objective Weighting method(SF-EW and WASPAS-SF)to evaluate international payment methods with uncertain ***,SF-EW model is applied to determine the relative weights of critical ***,international payment method alternatives are prioritized by the WASPAS-SF *** essential factors for four international payment methods are proposed based on experts’opinions and the existing literature.A real-world case study from Vietnamese import-export SMEs is presented to validate the applicability of the proposed *** results indicated that“Characteristics of payment method(PA)”had the most significant impact on international payment method *** comparison,“Letters of Credit(L/C)”was the most reliable payment method with the highest ranking available to international ***,a sensitivity analysis was performed to examine the validity and robustness of the proposed decision support ***,this study could contribute to international payment services and in the context of globalization and international trade.

关键词： International payment Vietnam MCDM spherical fuzzy theory entropy WASPAS

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A Chance–Constrained Data Envelopment Analysis Approach to Problem Provincial Productivity Growth in Vietnamese Agriculture from 1995 to 2007

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Open Journal of Statistics 2011年第3期1卷 217-235页

作者： nguyen Khac minh pham Van Khanh 不详

This study employs a chance-constrained data envelopment analysis (CDEA) approach with two models (model A and model B) to decompose provincial productivity growth in Vietnamese agriculture from 1995 to 2007 into technological progress and efficiency change. The differences between the chance - constrained programming model A and model B are assumptions imposed on the covariance matrix. The decomposition allows us to identify the contributions of technical change and the improvement in technical efficiency to productivity growth in Vietnamese production. Sixty-one provinces in Vietnam are classified into Mekong - technology and other -technology categories. We conduct a Mann-Whitney test to verify whether the two samples, the Mekong technology province sample and the other technology sample, are drawn from the same productivity change populations. The result of the Mann-Whitney test indicates that the differences between the Mekong technology category and the other technology category from two models are more significant. Two important questions are whether some provinces in the samples could maintain their relative efficiency rank positions in comparison with the others over the study period and how to further examine the agreements between the two models. The Kruskal - Wallis test statistic shows that technical efficiency from both models for some provinces are higher than those of them in the study period. The Malmquist results show that production frontier has contracted by around 1.3 percent and 0.31 percent from chance-constrained model A and model B, respectively, a year on average over the sample period. To examine the agreements or disagreements in the total factor productivity indexes we compute the correlation between Malmquist indexes, which is positive and not very high. thus there is a little discrepancy between the two Malmquist indexes, estimated from the chance - constrained models A and B.

关键词： Total Factor Productivity Technical Efficiency Change Technological Progress Chance-Constrained Programming

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Forecasting the Convergence State of per Capital Income in Vietnam

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American Journal of Operations Research 2013年第6期3卷 487-496页

作者： nguyen Khac minh pham Van Khanh Military Technical Academy Hanoi Vietnam National Economics University Hanoi Vietnam

Convergence problem of an economic variable represents an underlying forecast of neoclassical economic growth model. This paper aims to analyze the convergence of provincial per capita GDP stability in Vietnam over the period of 1991-2007. This can be done by two approaches including bias data-based regression method for testing convergence and Markov chain model for describing features of long-term tendency of per capita income in Vietnam growth in provinces. The regression method results in the signs of convergence. To apply Markov process, we divide total pattern into 5 per capita income classes. Result estimated from the Markov chain model shows the poor convergence.

关键词： Convergence Regression Method Markov Proces

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A New Species of Rhacophorus(Amphibia:Anura:Rhacophoridae)from Vietnam

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Asian Herpetological Research 2017年第4期18卷 221-234页

作者： Tao Thien nguyen Cuong The pham Truong Quang nguyen Hoa Thi NINH Thomas ZIEGLER Vietnam National Museum of Nature Vietnam Academy of Science and Technology18 Hoang Quoc Viet RoadHanoiVietnam Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiVietnam Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiVietnam The Kyoto University Museum Kyoto UniversityYoshida HonmachiSakyokuKyoto 606-8501Japan Hanoi National University of Education 136 Xuan ThuyCau GiayHanoiVietnam AG Zoologischer Garten K6ln Riehler Strasse 173D-50735 CologneGermany Institute of Zoology University of CologneZiilpicherStrafle 47bD-50674 CologneGermany

We describe a new species of Rhacophorus based on two adult specimens collected from Hoa Binh Province, northern Vietnam. Rhacophorus hoabinhensis sp. nov. is distinguishable from its congeners on the basis of a combination of the following morphological characters： size small （SVL 31.1-32.5 mm in males）; head slightly longer than wide; vomerine teeth absent; snout short （SNL/SVL 0.16）; dorsal skin smooth; forearm and tarsus with dermal fringes; dermal appendage at vent present; webbing formula on fingers I12/3-12/3II1-2III1-1IV and on toes I3/4-1II1/2- IIII1/2-1IVI-1/2V; dorsal surface grey yellow with brown spots; lower jaw region dark grey, throat, chest and belly cream; anterior and posterior thighs, as well as ventral surface of tibia orange. The interspecific uncorrected genetic distances （16S rRNA gene） between the new species from Hoa Binh and other analyzed congeners varied from 9.8% to 17.4%. In the phylogenetic analyses, the new species revealed to be a representative of Rhacophorus and was nested within the R. hoanglienensis-orlovi species group.

关键词： Rhacophorus hoabinhensis sp.nov karst forest molecular phylogeny taxonomy Hoa Binh Province

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Productivity Growth, Technological Progress, and Efficiency Change in Vietnamese Manufacturing Industries: A Stochastic Frontier Approach

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Open Journal of Statistics 2012年第2期2卷 224-235页

作者： nguyen Khac minh pham Van Khanh nguyen Thi minh nguyen Thi Phuong Anh Faculty of Economics Water Resources University Hanoi Vietnam Hanoi University of Science and Technology Hanoi Vietnam Military Technical Academy Hanoi Vietnam National Economics University Hanoi Vietnam

This study applies a stochastic frontier production approach to decompose the sources of total productivity (TFP) growth into technical progress and changes in technical efficiency of 8057 firms in Vietnamese manufacturing industries during 2003-2007. Using both total manufacturing industry and sub-manufacturing industrial regressions, the analysis focuses on the trend of technological progress (TP) and technical efficiency change (TEC), and the role of productivity change in economic growth. According to the estimated results, the annual technical progress for the manufacturing industry and sub-manufacturing industries are calculated directly from the estimated parameters of the translog stochastic frontier production function by taking a partial derivative of output with respect to time t. The average technical changes in manufacturing industry and sub-manufacturing industries are positive, with an average technical change about 5.2%, 5.8%, 5.4%, 11.8%, 4.6%, 4.1%, 7.3%, 4.8%, 4.8% and 4.8% for total sample, food products & beverages, textile & wearing apparel, footwear, paper & products, industrial chemicals, rubber & plastic products, non- metallic mineral, basic & fabricated metal and other sub-industries, respectively. Total TFP in the manufacturing sector has grown at the annual rate of 0.052, although the rate of growth decreased continuously during the sample period. For the sub-industry estimates during the sample period, TFP grew fastest in the footwear sub-industry, with annual average growth rate of 11.8%, followed by the rubber & plastic products with a rate of 7.3%, and the food products & beverages with a rate of 5.8% per annum.

关键词： Total Factor Productivity Technical Efficiency Change Technological Progress Stochastic Frontier Approach Vietnamese Manufacturing Industry

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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

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