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Ensemble machine learning models based on Reduced Error Pruning Tree for prediction of rainfall-induced landslides

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International Journal of Digital Earth 2021年第5期14卷 575-596页

作者： Binh Thai Pham Abolfazl Jaafari Trung nguyen-Thoi Tran Van phong Huu Duy nguyen Neelima Satyam Md Masroor Sufia Rehman Haroon Sajjad Mehebub Sahana Hiep Van Le Indra Prakash Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam Research Institute of Forests and Rangelands Agricultural ResearchEducationand Extension Organization(AREEO)TehranIran Institute of Geological Sciences Vietnam Academy of Sciences and TechnologyHanoiViet Nam Faculty of Geography V.N.U.University of ScienceVietnam National UniversityHanoiViet Nam Discipline of Civil Engineering Indian Institute of Technology IndoreMadhya PradheshIndia Department of Geography Jamia Millia IslamiaNew DelhiIndia School of Environment Education and DevelopmentUniversity of ManchesterManchesterUK Institute of Research and Development Duy Tan UniversityDa NangViet Nam DDG(R)Geological Survey of India GujaratIndia

In this paper,we developed highly accurate ensemble machine learning models integrating Reduced Error Pruning Tree(REPT)as a base classifier with the Bagging(B),Decorate(D),and Random Subspace(RSS)ensemble learning techniques for spatial prediction of rainfallinduced landslides in the Uttarkashi district,located in the Himalayan range,*** do so,a total of 103 historical landslide events were linked to twelve conditioning factors for generating training and validation *** Mean Square Error(RMSE)and Area Under the receiver operating characteristic Curve(AUC)were used to evaluate the training and validation performances of the *** results showed that the single REPT model and its derived ensembles provided a satisfactory accuracy for the prediction of *** D-REPT model with RMSE=0.351 and AUC=0.907 was identified as the most accurate model,followed by RSS-REPT(RMSE=0.353 and AUC=0.898),B-REPT(RMSE=0.396 and AUC=0.876),and the single REPT model(RMSE=0.398 and AUC=0.836),*** prominent ensemble models proposed and verified in this study provide engineers and modelers with insights for development of more advanced predictive models for different landslide-susceptible areas around the world.

关键词： Machine learning ensemble modeling Bagging Decorate Random Subspace

Visualized SERS Imaging of Single Molecule by Ag/ Black Phosphorus Nanosheets

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Nano-Micro Letters 2022年第5期14卷 47-61页

作者： Chenglong Lin Shunshun Liang Yusi Peng Li Long Yanyan Li Zhengren Huang nguyen viet Long Xiaoying Luo Jianjun Liu Zhiyuan Li Yong Yang State Key Laboratory of High‑Performance Ceramics and Superfine Microstructures Shanghai Institute of CeramicsChinese Academy of Sciences1295 Dingxi RoadShanghai 200050People’s Republic of China Graduate School of the Chinese Academy of Sciences No.19(A)Yuquan RoadBeijing 100049People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China State Key Laboratory of Oncogenes and Related Genes Shanghai Cancer InstituteRenji HospitalShanghai Jiaotong University School of Medicine200032 ShanghaiPeople’s Republic of China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641People’s Republic of China Department of Electronics and Telecommunications Saigon UniversityHochiminh CityVietnam

Single-molecule detection and imaging are of great value in chemical analysis,biomarker identification and other trace detection ***,the localization and visualization of single molecule are still quite a ***,we report a special-engineered nanostructure of Ag nanoparticles embedded in multi-layer black phosphorus nanosheets(Ag/BP-NS)synthesized by a unique photoreduction method as a surfaceenhanced Raman scattering(SERS)*** a SERS substrate features the lowest detection limit of 10^(–20) mol L^(−1) for R6G,which is due to the three synergistic resonance enhancement of molecular resonance,photoinduced charge transfer resonance and electromagnetic *** propose a polarization-mapping strategy to realize the detection and visualization of single *** addition,combined with machine learning,Ag/BP-NS substrates are capable of recognition of different tumor exosomes,which is meaningful for monitoring and early warning of the *** work provides a reliable strategy for the detection of single molecule and a potential candidate for the practical bio-application of SERS technology.

关键词： Black phosphorus Single molecule SERS Exosome Machine learning

Stable Vertical Takeoff of an Insect-Mimicking Flapping-Wing System Without Guide Implementing Inherent Pitching Stability

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Journal of Bionic Engineering 2012年第4期9卷 391-401页

作者： Hoang Vu Phan Quoc viet nguyen Quang Tri Truong Tien Van Truong Hoon Cheol Park Nam Seo Goo Doyoung Byun Min Jun Kim Department of Advanced Technology Fusion Konkuk University Seoul 143-701 Korea Department of Aerospace Engineering Konkuk University Seoul 143-701 Korea Department of Mechanical Engineering Sungkyunkwan University Seoul 143-701 Korea Department of Mechanical Engineering and Mechanics Drexel University Philadelphia USA

We briefly summarized how to design and fabricate an insect-mimicking flapping-wing system and demonstrate how to implement inherent pitching stability for stable vertical takeoff. The effect of relative locations of the Center of Gravity （CG） and the mean Aerodynamic Center （AC） on vertical flight was theoretically examined through static force balance considera- tion. We conducted a series of vertical takeoff tests in which the location of the mean AC was determined using an unsteady Blade Element Theory （BET） previously developed by the authors. Sequential images were captured during the takeoff tests using a high-speed camera. The results demonstrated that inherent pitching stability for vertical takeoff can be achieved by controlling the relative position between the CG and the mean AC of the flapping system.

关键词： beetle flapping-wing system insect-mimicking insect flight inherent pitching stability vertical takeoff

Behavior of noncircular tunnels excavated in stratified rock masses-Case of underground coal mines

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 99-110页

作者： Ngoc Anh Do Daniel Dias Van Diep Dinh Tien Tung Tran Van Canh Dao viet Doan Dao Phuc Nhan nguyen Department of Underground and Mining Construction.Faculty of Civil Engineering Hanoi University of Mining and Ceology School of Automotive and Transportation Engineering Hefei University of Technology Laboratory 35R Crenoble Alpes University

The amount of tunnels excavated along stratified/sedimentary rock masses in Quangninh coal mine area,vietnam, is gradually increasing. Rock mass in Quangninh is characterized by beddings between rock layers. The behavior of stratified rock masses surrounding the tunnels depends on both the intact rock and the beddings between rock layers. The main characteristics of stratified rock masses that need to be considered are their heterogeneity and anisotropy. Depending on the dip angle of rock layers, movements and failure zones developed surrounding the tunnels can be asymmetrical over the vertical axis of tunnel. This asymmetry causes adverse behaviors of the tunnel structures. The objective of this study is to highlight convergences and yielded zones developed in rock masses surrounding noncircular tunnels in Quangninh coal mine area using a finite element method. The presence of bedding joints is explicitly simulated. The numerical results indicated that with the increase in dip angle of bedding joints, the stress asymmetry over the tunnel vertical axis increases. It gradually leads to an asymmetry of the failure zone surrounding the tunnel. An increase of rock mass quality means a decrease of rock mass sensitivity to the discontinuities. In addition,a dip angle of the bedding joints of approximately 45° could be considered as the critical angle at which the rock mass mechanism changes between sliding and bending.

关键词： Tunnel Bedding Stratification Anisotropic Heterogeneity

Natural variables separate the endemic areas of Clonorchis sinensis and Opisthorchis viverrini along a continuous, straight zone in Southeast Asia

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贫困所致传染病(英文) 2024年第02期13卷 39-51页

作者： Zheng Jin-Xin Zhu Hui-Hui Xia Shang Qian Men-Bao nguyen Hung Manh Sripa Banchob Sayasone Somphou Khieu Virak Bergquist Robert Zhou Xiao-Nong School of Global Health Chinese Center for Tropical Diseases Research Shanghai Jiao Tong University School of Medicine Shanghai China One Health Center Shanghai Jiao Tong University The University of Edinburgh Shanghai China National Institute of Parasitic Diseases at Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research) NHC Key Laboratory of Parasites and Vectors Biology WHO Collaborating Centre for Tropical Diseases National Center for International Research on Tropical Diseases Shanghai China Institute of Ecology and Biological Resources Graduate University of Science and Technology Vietnam Academy of Science and Technology Hoang Quoc Viet Street Hanoi Vietnam WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease) Tropical Disease Research Laboratory Department of Tropical Medicine Faculty of Medicine Khon Kaen University Mittraparb Road Khon Kaen Thailand Lao Tropical and Public Health Institute Ministry of Health Vientiane Lao PDR National Centre for Parasitology Entomology and Malaria Control Ministry of Health Phnom Penh Cambodia Ingerod Brastad Sweden (formerly at the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases) World Health Organization Geneva Switzerland

Background Clonorchiasis and opisthorchiasis, caused by the liver flukesClonorchis sinensis andOpisthorchis viverrini respectively, represent significant neglected tropical diseases (NTDs) in Asia. The co-existence of these pathogens in overlapping regions complicates effective disease control strategies. This study aimed to clarify the distribution and interaction of these diseases within Southeast *** We systematically collated occurrence records of human clonorchiasis (n = 1809) and opisthorchiasis (n = 731) across the Southeast Asia countries. Utilizing species distribution models incorporating environmental and climatic data, coupled machine learning algorithms with boosted regression trees, we predicted and distinguished endemic areas for each fluke species. Machine learning techniques, including geospatial analysis, were employed to delineate the boundaries between these *** Our analysis revealed that the endemic range ofC. sinensis andO. viverrini in Southeast Asia primarily spans across part of China, vietnam, Thailand, Laos, and Cambodia. During the period from 2000 to 2018, we identifiedC. sinensis infections in 84 distinct locations, predominantly in southern China (Guangxi Zhuang Autonomous Region) and northern vietnam. In a stark contrast,O. viverrini was more widely distributed, with infections documented in 721 locations across Thailand, Laos, Cambodia, and vietnam. Critical environmental determinants were quantitatively analyzed, revealing annual mean temperatures ranging between 14 and 20 °C in clonorchiasis-endemic areas and 24–30 °C in opisthorchiasis regions (P vietnam delineates the coexistence and geographical boundaries ofC. sinensis andO. viverrini, revealing distinct endemic zones and a transitional area where both live

关键词： Liver fluke Clonorchiasis Opisthorchiasis Clonorchis sinensis Opisthorchis viverrine Southeast Asia Machine learning Ecological study

Effects of Perforated Baffle on Reducing Sloshing in Rectangular Tank:Experimental and Numerical Study

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China Ocean Engineering 2013年第5期27卷 615-628页

作者：薛米安林鹏智郑金海马玉祥苑晓丽 viet-Thanh nguyena State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Harbour Coastal and Offshore Engineering Hohai University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology College of Mechanics and Materials Hohai University

A liquid sloshing experimental rig driven by a wave-maker is designed and built to study liquid sloshing problems in a rectangular liquid tank with perforated baffle. A series of experiments are conducted in this experimental rig to estimate the free surface fluctuation and pressure distribution by changing external excitation frequency of the shaking table. An in-house CFD code is also used in this study to simulate the liquid sloshing in three-dimensional （3D） rectangular tank with perforated baffle. Good agreements of free surface elevation and pressure between the numerical results and the experimental data are obtained and presented. Spectral analysis of the time history of free surface elevation is conducted by using the fast Fourier transformation.

关键词： liquid sloshing experimental study rectangular tank perforated baffle

Cholecystitis-an uncommon complication following thoracic duct embolization for chylothorax: A case report

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World Journal of Clinical Cases 2022年第24期10卷 8775-8781页

作者： Le viet Dung Ma Mai Hien Thieu-Thi Tra My Doan Tien Luu Le Tuan Linh nguyen Minh Duc Diagnostic Imaging and Interventional Radiology Center Hanoi Medical University HospitalHanoi 100000Vietnam Department of Radiology Hanoi Medical UniversityHanoi 100000Vietnam Department of Radiology Pham Ngoc Thach University of MedicineHo Chi Minh 700000Vietnam

BACKGROUND Chylothorax is an uncommon condition in which chyle leaks into the pleural cavity,and biliary peritonitis is a rare complication of thoracic duct embolization in clinical *** SUMMARY We describe the case of a 50-year-old woman who presented with chylothorax and underwent thoracic duct embolization using a coil and a mixture of histoacryl glue and *** patient developed upper abdominal pain and fever after the *** was diagnosed with biliary peritonitis and treated with cholecystectomy at Hanoi Medical University *** Although thoracic duct embolization is considered a safe and minimally invasive procedure,it is not without *** thoracic duct embolization,severe or persistent abdominal pain should be explored utilizing imaging data and laboratory results to determine problems as soon as possible.

关键词： Lymphangiography Thoracic duct embolization Cholecystitis Chyle leakage Biliary peritonitis Case report

Corporate Governance and Debt Management of vietnam＇s SMEs

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Economics World 2015年第2期3卷 91-96页

作者： Pham Thu Ha nguyen Tien phong Hanoi University of Technology Hanoi Vietnam

The paper aims to examine the relationship between corporate governance and debt management of vietnam＇s small and medium enterprises （SMEs）, in a case study of a specific enterprise. It reveals one case that corporate governance factors have strong correlation with performance, due to transparency to the lender, innovative and consistent to the debt management. The results indicate that timely reporting and level of disclosure positively affect corporate performance and ability to raise funds in the financial market. The paper seeds new light into the relationship between corporate governance and debt management of vietnam＇s SMEs in current context. It finds ways to solve financial dilemma and raise corporate equity value that most SMEs are facing.

关键词： corporate governance renovation transparency debt management small and medium enterprises(SMEs) debt restructuring

A RELAXED INERTIAL FACTOR OF THE MODIFIED SUBGRADIENT EXTRAGRADIENT METHOD FOR SOLVING PSEUDO MONOTONE VARIATIONAL INEQUALITIES IN HILBERT SPACES

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Acta Mathematica Scientia 2023年第1期43卷 184-204页

作者： Duong viet THONG Vu Tien DUNG Division of Applied Mathematics Thu Dau Mot UniversityBinh Duong ProvinceVietnam Department of Mathematics University of ScienceVietnam National University334 Nguyen TraiThanh XuanHanoiVietnam

In this paper,we investigate pseudomonotone and Lipschitz continuous variational inequalities in real Hilbert *** solving this problem,we propose a new method that combines the advantages of the subgradient extragradient method and the projection contraction *** very recent papers have considered different inertial algorithms which allowed the inertial factor is chosen in[0;1].The purpose of this work is to continue working in this direction,we propose another inertial subgradient extragradient method that the inertial factor can be chosen in a special case to be *** suitable mild conditions,we establish the weak convergence of the proposed ***,linear convergence is obtained under strong pseudomonotonicity and Lipschitz continuity ***,some numerical illustrations are given to confirm the theoretical analysis.

关键词： subgradient extragradient method inertial method variational inequality problem pseudomonotone mapping strong convergence convergence rate