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Prediction of Flash Flood Susceptibility of Hilly Terrain Using Deep Neural Network:A Case Study of Vietnam

Computer Modeling in Engineering & Sciences 2023年第6期135卷 2219-2241页

作者： Huong Thi thanh Ngo Nguyen Duc Dam Quynh-Anh Thi Bui Nadhir Al-Ansari Romulus Costache Hang Ha Quynh Duy Bui Sy Hung Mai Indra Prakash Binh Thai pham University of Transport Technology Hanoi100000Vietnam Department of Civil Environmental and Natural Resources EngineeringLulea University of TechnologyLulea97187Sweden Department of Civil Engineering Transilvania University of BrasovBrasov500152Romania Danube Delta National Institute for Research and Development Tulcea820112Romania Departement of Geodesy and Geomatics National University of Civil EngineeringHanoi100000Vietnam Faculty of Hydraulic Engineering National University of Civil EngineeringHanoi100000Vietnam DDG(R)Geological Survey of India Gandhinagar382010India

Flash floods are one of the most dangerous natural disasters,especially in hilly terrain,causing loss of life,property,and infrastructures and sudden disruption of *** types of floods are mostly associated with landslides and erosion of roads within a short *** of Vietnamis hilly and mountainous;thus,the problem due to flash flood is severe and requires systematic studies to correctly identify flood susceptible areas for proper landuse planning and traffic *** this study,three Machine Learning(ML)methods namely Deep Learning Neural Network(DL),Correlation-based FeatureWeighted Naive Bayes(CFWNB),and Adaboost(AB-CFWNB)were used for the development of flash flood susceptibility maps for hilly road section(115 km length)of National Highway(NH)-6 inHoa Binh province,*** the proposedmodels,88 past flash flood events were used together with 14 flash floods affecting topographical and geo-environmental *** performance of themodels was evaluated using standard statisticalmeasures including Receiver Operating Characteristic(ROC)Curve,Area Under Curve(AUC)and Root Mean Square Error(RMSE).The results revealed that all the models performed well(AUC>0.80)in predicting flash flood susceptibility zones,but the performance of the DL model is the best(AUC:0.972,RMSE:0.352).Therefore,the DL model can be applied to develop an accurate flash flood susceptibility map of hilly terrain which can be used for proper planning and designing of the highways and other infrastructure facilities besides landuse management of the area.

关键词： Flash flood deep learning neural network(DL) machine learning(ML) receiver operating characteristic curve(ROC) Vietnam

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The Dynamics and Control of the Fractional Forms of Some Rational Chaotic Maps

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Journal of Systems Science & Complexity 2020年第3期33卷 584-603页

作者： OUANNAS Adel KHENNAOUI Amina-Aicha BENDOUKHA Samir WANG Zhen pham Viet-thanh Laboratory of Mathematics Informatics and Systems(LAMIS)University of Larbi TebessiTebessa 12002Algeria Department of Mathematics and Computer Sciences University of Larbi Ben M'hidiOum El BouaghiAlgeria Department of Electrical Engineering College of EngineeringYanbuTaibah UniversitySaudi Arabia Shaanxi Engineering Research Center of Controllable Neutron Source School of ScienceXijing UniversityXi'an 710123China Faculty of Electrical and Electronic Engineering Phenikaa Institute for Advanced Study(PIAS)Phenikaa UniversityYen NghiaHa Dong districtHanoi 100000Vietnam Phenikaa Research and Technology Institute(PRATI) A&A Green Phoenix Group167 Hoang NganHanoi 100000Vietnam

This paper proposes three fractional discrete chaotic systems based on the Rulkov,Chang,and Zeraoulia–Sprott rational *** dynamics of the proposed maps are investigated by means of phase plots and bifurcations *** stabilization schemes are proposed for each of the three maps and the convergence of the states is established by using the Lyapunov ***,a combination synchronization scheme is proposed whereby a combination of the fractional Rulkov and Chang maps is synchronized to the fractional Zeraoulia-Sprott *** results are used to confirm the findings of the paper.

关键词： Fractional discrete chaos fractional rational maps stabilization synchronization

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A Neural-network-based Approach to Study the Energy-optimal Hovering Wing Kinematics of a Bionic Hawkmoth Model

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Journal of Bionic Engineering 2019年第5期16卷 904-915页

作者： Anh Tuan Nguyen Ngoc Doan Tran thanh Trung Vu thanh Dong pham Quoc Tru Vu Jae-Hung Han Faculty of Aerospace Engineering Le Quy Don Technical University236 Hoang Quoc VietVietnam Office of International Cooperation Le Quy Don Technical University236 Hoang Quoc VietVietnam Department ofAerospace Engineerings Korea Advanced Institute of Science and Technology Daejeon 34141Republic ofKorea

This paper presents the application of an artificial neural network to develop an approach to determine and study the energy-optimal wing kinematics of a hovering bionic hawkmoth model.A three-layered artificial neural network is used for the rapid prediction of the unsteady aerodynamic force acting on the wings and the required *** this artificial network is integrated into genetic and simplex algorithms,the running time of the optimization process is reduced *** validity of this new approach is confirmed in a comparison with a conventional method using an aerodynamic model based on an extended unsteady vortex-lattice method for a sinu soidal wing kinematics *** studying the obtained results,it is found that actual hawkmoths do not hover under an energy-optimal ***,by tilting the stroke plane and lowering the wing positions,they can compromise and expend some energy to enhance their maneuverability and the stability of their flight.

关键词： optimal hovering wing kinematics artificial neural network insect flight genetic algorithm unsteady vortex-lattice method bionics

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外商直接投资对越南行业收入的影响与政策优化研究——以电力等六个行业为例

外商直接投资对越南行业收入的影响与政策优化研究——以电力等六...

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作者： pham Thi thanh Hoa 华南理工大学

学位级别：硕士

越南在近年来逐渐成为东南亚极具发展潜力的国家,尽管受新冠肺炎疫情影响增速下滑,但仍是世界上实现经济正增长的国家之一。目前,越南依然是一个中低收入的国家,所以国家的发展还必须依靠朝阳产业的发展。由于政府的资金有限,所以朝阳... 详细信息

越南在近年来逐渐成为东南亚极具发展潜力的国家,尽管受新冠肺炎疫情影响增速下滑,但仍是世界上实现经济正增长的国家之一。目前,越南依然是一个中低收入的国家,所以国家的发展还必须依靠朝阳产业的发展。由于政府的资金有限,所以朝阳产业发展的过程中很大程度需要依靠外商直接投资来促进行业的发展。外商直接投资会对国内居民的收入造成影响,而且这种影响在各行业、各地区均存在差异。本文主要研究外商直接投资规模对越南重点行业、重点省份的外资企业的从业人员的收入水平的影响。首先,本文通过越南外商直接投资发展现状、越南六大重点行业发展现状进行阐述,然后通过实证分析研究外商直接投资对越南六大代表行业(电力行业、交通行业、制造业、软件与信息技术服务业行业、建筑行业及房地产行业)的影响。为使得研究更加深入,本文还对越南国六大省份展开实证研究,以六大省份(北部选取河内(H(?)N(?)i),海防(H(?)i Ph(?)ng),北宁(B(?)c Ninh)三大省份,南部选取胡志明(H(?)Ch(?)Minh),铜奈((?)ng Nai),平阳(B(?)nh D(?)ng)三大省份)的居民收入水平为样本,研究其是否受到外商直接投资的影响以及该影响的地区差异。结论认为,从行业、地区整体来看,外商直接投资能促进工资收入水平,但结构性差异也是存在的。其中,对于不同行业来说,外商直接投资提高了电力行业、交通行业、软件行业、建筑业的工资收入水平。而制造业的工资收入与外商直接投资呈现反方向变动关系。此外,外商直接投资在房地产行业并不能促进工资收入的提高,二者间无关系。对于越南不同地区来说,南部省份收入水平受到外商直接投资的贡献作用大于北部省份。最后本文得出实证分析的结果,提出具有针对性的政策建议。

关键词：外商直接投资收入分配政策优化

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Carboxymethyl starch cross-linked by electron beam radiation in presence of acrylic acid sensitizer

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Nuclear Science and Techniques 2013年第B12期24卷 19-22页

作者： Doan Binh Nguyen thanh Duoc pham Thi Thu Hong R & D Center for Radiation Technology Vietnam Atomic Energy Institute 202A St. 11 Linh Xuan Ward Thu Duc District Ho Chi Minh City Vietnam

Carboxymethyl starch (CMS) can be cross-linked by electron beam radiation to form a biocompatible and environment-friendly hydrogel at a high absorbed dose and a condensed CMS concentration. Acrylic acid (AAc) can be used as a sensitizer in order to reduce the absorbed doses to an acceptable certain level. At an absorbed dose of 3-4 kGy, the gel content of crosslinked CMS can be obtained about 50% with 5% (w/w) AAc concentration used. The compressive strength of CMS samples increased with increasing their cross-linked densities due to raising absorbed doses. The swelling ratio of cross-linked CMS was also attainable at a maximum of 50 times in the distilled water. The enzymatic degradation of cross-linked CMS was carried out in acetate buffer pH 4.6 with 0.1% α-amylase enzymatic solution incubated at 40°C for 6 h. The crosslinked CMS samples were degraded slower than uncrosslinked CMS ones. The results indicated that the highly cross-linked CMS was almost fully degradable when the enzymatic hydrolysis was performed during 6 h. The FT IR spectra of cross-linked CMS in the presence of AAc were examined to observe the carboxyl group of AAc in the structure of cross-linked CMS. The hydrophilic of cross-linked CMS surface was determined by a contact-angle analysis. © 2013, Science Press. All rights reserved.

关键词：交联密度羧甲基淀粉电子束辐射丙烯酸敏化剂 FT-IR光谱吸收剂量 CMS

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Hidden attractors in a new fractional-order discrete system: Chaos, complexity, entropy, and control

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Chinese Physics B 2020年第5期29卷 174-181页

作者： Adel Ouannas Amina Aicha Khennaoui Shaher Momani Viet-thanh pham Reyad El-Khazali Laboratory of Mathematics Informatics and Systems(LAMIS)University of Laarbi TebessiTebessa12002Algeria College of Humanities and Sciences Ajman UniversityAjmanUAE Laboratory of Dynamical Systems and Control University of Larbi Ben M’hidiOum El BouaghiAlgeria Department of Mathematics Faculty of ScienceUniversity of JordanAmman 11942Jordan Nonlinear Systems and Applications Faculty of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam ECCE Department Khalifa UniversityAbu-Dhabi 127788United Arab Emirates

This paper studies the dynamics of a new fractional-order discrete system based on the Caputo-like difference *** is the first study to explore a three-dimensional fractional-order discrete chaotic system without *** phase portrait,bifurcation diagrams,and largest Lyapunov exponents,it is shown that the proposed fractional-order discrete system exhibits a range of different dynamical ***,different tests are used to confirm the existence of chaos,such as 0-1 test and C0 *** addition,the quantification of the level of chaos in the new fractional-order discrete system is measured by the approximate entropy ***,based on the fractional linearization method,a one-dimensional controller to stabilize the new system is *** results are presented to validate the findings of the paper.

关键词： discrete chaos discrete fractional calculus hidden attractor

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Nitroxy-and azidomethyl azofurazans as advanced energetic materials

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Defence Technology（防务技术） 2022年第8期18卷 1369-1381页

作者： Aleksei B.Sheremetev Svetlana F.Mel'nikova Elizaveta S.Kokareva Ruslan E.Nekrutenko Kirill V.Strizhenko Kyrill Yu Suponitsky thanh Dat pham Alla N.Pivkina Valery P.Sinditskii Zelinsky Institute of Organic Chemistry Russian Academy of Sciences47 Leninsky ProspMoscow119991Russia Saint Petersburg State Institute of Technology 26 Moskovskii PrSt Petersburg190013Russia Mendeleev University of Chemical Technology Moscow125047Russia N.N.Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences4 Kosygina Str119991MoscowRussia

Progress in the rocket industry is only possible on the basis of new, higher performance and more environmentally friendly materials compared to up-to-date propellant ingredients for liquid, solid, gelled and hybrid propellant systems. In this work, synthetic methods have been developed for the preparation of new energetic azofurazans bearing nitroxymethyl or azidomethyl groups. All prepared compounds were fully characterized by multinuclear NMR and IR spectroscopies, as well as elemental analyses. An analysis of the structural features based on the X-ray single-crystal diffraction made it possible to discuss their influence on the densities of the azofurazans of this study. Thermal decomposition and combustion of nitroxymethyl and azidomethyl azofurazans were studied using a number of complementary experimental techniques, namely thermogravimetry, differential scanning calorimetry, manometry, microthermocouple measurements in the combustion wave. The structural and physical characteristics of these new energetic analogues illustrate the extent to which the nature of the explosophoric groups can be used to tune the performace of the azofurazan framework. These azofurazans possess positive calculated enthalpy of formation and are promising candidates for new environmentally friendly energetic materials.

关键词： Azofurazan Azide Nitrate ester X-ray Combustion

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Chimera state in a network of nonlocally coupled impact oscillators

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第3期22卷 235-244页

作者： Jerzy WOJEWODA Karthikeyan RAJAGOPAL Viet-thanh pham Fatemeh PARASTESH Tomasz KAPITANIAK Sajad JAFARI Division of Dynamics Lodz University of TechnologyLodz90-924Poland Nonlinear Systems and Applications Faculty of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam Biomedical Engineering Department Amirkabir University of TechnologyTehran15875-4413Iran Health Technology Research Institute Amirkabir University of TechnologyTehran15875-4413Iran

Chimera state is a peculiar spatiotemporal pattern,wherein the coherence and incoherence coexist in the network of coupled identical *** this paper,we study the chimera states in a network of impact oscillators with nonlocal *** investigate the effects of the coupling strength and the coupling range on the network *** results reveal the emergence of the chimera state for significantly small values of coupling strength,and higher coupling strength values lead to unbounded motions in the *** also study the network in the case of excitation *** observe that the coupling helps in the maintenance of an oscillatory motion with a lower amplitude in the failed oscillator.

关键词： Mechanical oscillators Impact oscillator Coupled network Nonlocal coupling Chimera state

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Novel Criteria for Exponential Stability of Linear Non-Autonomous Functional Differential Equations

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Journal of Systems Science & Complexity 2019年第2期32卷 479-495页

作者： pham HUU ANH Ngoc Thai BAO Tran CAO thanh Tinh NGUYEN DINH Huy Department of Mathematics Vietnam National University-HCMC International University Faculty of Information Systems Vietnam National University-HCMC University of Information Technology Department of Mathematics Vietnam National University-HCMC University of Information Technology Division of Applied Mathematics Faculty of Applied Sciences Vietnam National University-HCMC Ho Chi Minh city University of Technology

General linear non-autonomous functional differential equations are considered. Explicit criteria for exponential stability are given. Furthermore, the authors present an explicit robust stability bound for systems su... 详细信息

关键词： Exponential stability linear functional differential equations perturbation

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Graphical method based on modified maximum force criterion to indicate forming limit curves of 22MnB5 boron steel sheets at elevated temperatures

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Journal of Iron and Steel Research(International) 2021年第8期28卷 1009-1018页

作者： thanh Luyen Quoc-Tuan pham Thi-Bich Mac Tien-Long Banh Duc-Toan Nguyen Faculty of Mechanical Engineering Hungyen University of Technology and EducationHungyen 160000Vietnam Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh City 70000Vietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh City 70000Vietnam School of Mechanical Engineering Hanoi University of Science and TechnologyHanoi City 100000Vietnam

A new approach for predicting forming limit curves(FLCs)at elevated temperatures was proposed *** are often used to predict failure and determine the optimal forming parameters of automotive ***,a graphical method based on a modified maximum force criterion was applied to estimate the FLCs of 22MnB5 boron steel sheets at room temperature using various hardening ***,the predicted FLC data at room temperature were compared with corresponding data obtained from Nakazima's tests to obtain the best *** estimate the FLC at elevated temperatures,tensile tests were conducted at various temperatures to determine the ratios of equivalent fracture strains between the corresponding elevated temperatures and room *** at elevated temperatures could be established based on obtained ***,the predicted FLCs at elevated temperatures did not agree well with the corresponding FLC experimental data of Zhou et al.A new method was proposed herein to improve the prediction of FLCs at elevated *** FLC calculated at room tem-perature was utilized to predict the failure of Nakazima's samples via finite element *** on the simulation results at room temperature,the mathematical relationships between the equivalent ductile fracture strain versus stress triaxiality and strain ratio were established and then combined with ratios between elevated and room temperatures to calculate the FLCs at different *** predicted FLCs at elevated temperatures agree well with the corresponding experimental FLC data.

关键词： Forming limit curve Modified maximum force criterion Graphical method Hardening law Finite element method Boron steel sheet Elevated temperature

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