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Robust exponential stability and stabilization of linear uncertain polytopic time-delay systems

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控制理论与应用（英文版） 2008年第2期6卷 163-170页

作者： Nam PHAN t. Phat.vu N. Department of Mathematics Quynhon UniversityQuynhonBinhdinhVietnam Institute of Mathematics 18 Hoang Quoc Viet RoadHanoiVietnam

this paper proposes new sufficient conditions for the exponential stability and *** linear uncertain polytopic time-delay systems. the conditions for exponential stability are expressed in terms of Kharitonov-type linear matrix inequalities （LMIs） and we develop control design methods based on LMIs for solving stabilization problem. Our method consists of a combination of the LMI approach and the use of parameter-dependent Lyapunov functionals, which allows to compute simultaneously the two bounds that characterize the exponetial stability rate of the solution. Numerical examples illustrating the conditions are given.

关键词： Polytopic time-delay system Exponential stability Stabilization Parameter-dependent Lyapunov function Linear matrix inequalities

A combination of damage locating vector method （DLV） and differential evolution algorithm （DE） for structural damage assessment

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Frontiers of Structural and Civil Engineering 2018年第1期12卷 92-108页

作者： t. NGUYEN-tHOI A. tRAN-VIEt N. NGUYEN-MINH t. VO-DUY V. HO-huu Division of Computational Mathematics and Engineering Institute for Computational Science Ton Duc Thang University Hochiminh City Vietnam Division of Construction Computation Institute for Computational Science Ton Duc Thang University Hochiminh City Vietnam Faculty of Civil Engineering Ton Duc Thang University Hochiminh City Vietnam

In this study, a two-stage method is presented for identifying multiple damage scenarios. In the first stage, the damage locating vector （DLV） method using normalized cumulative energy （nce） is employed for damage localization in structures. In the second stage, the differential evolution algorithm （DE） is used for damage severity of the structures. In addition, in the second stage, a modification of an available objective function is made for handing the issue of symmetric structures. to verify the effectiveness of the present technique, numerical examples of a 72-bar space truss and a one-span steel portal frame are considered. In addition, the effect of noise on the performance of the identification results is also investigated. the numerical results show that the proposed combination gives good assessment of damage location and extent for multiple structural damage cases.

关键词： damage assessment damage locating vector method (DLV) differential evolution (DE) multiple damagelocation assurance criterion (MDLAC) mode shape error function

Improved flood susceptibility mapping using a best first decision tree integrated with ensemble learning techniques

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Geoscience Frontiers 2021年第3期12卷 333-342页

作者： Binh thai Pham Abolfazl Jaafari tran Van Phong Hoang Phan Hai Yen tran thi tuyen vu Van Luong huu Duy Nguyen Hiep Van Le Loke Kok Foong University of transport technology Ha Noi 100000Viet Nam Research Institute of Forests and Rangelands Agricultural ResearchEducation and Extension Organization(AREEO)TehranIran Institute of Geological Sciences Vietnam Academy of Sciences and Technology84 Chua Lang StreetDong daHa NoiViet Nam Department of Geography School of Social EducationVinh UniversityViet Nam Department of Resource and Environment Management School of Agriculture and ResourcesVinh UniversityViet Nam Faculty of Geography VNU University of Science334 Nguyen TraiHa NoiViet Nam Institute of Research and Development Duy Tan UniversityDa Nang 550000Viet Nam Department for Management of Science and technology Development Ton Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam

Improving the accuracy of flood prediction and mapping is crucial for reducing damage resulting from flood *** this study,we proposed and validated three ensemble models based on the Best First Decision tree(BFt)and the Bagging(Bagging-BFt),Decorate(Bagging-BFt),and Random Subspace(RSS-BFt)ensemble learning techniques for an improved prediction of flood susceptibility in a spatially-explicit manner.A total number of 126 historical flood events from the Nghe An Province(Vietnam)were connected to a set of 10 flood influencing factors(slope,elevation,aspect,curvature,river density,distance from rivers,flow direction,geology,soil,and land use)for generating the training and validation *** models were validated via several performance metrics that demonstrated the capability of all three ensemble models in elucidating the underlying pattern of flood occurrences within the research area and predicting the probability of future flood *** on the Area Under the receiver operating characteristic Curve(AUC),the ensemble Decorate-BFt model that achieved an AUC value of 0.989 was identified as the superior model over the RSS-BFt(AUC=0.982)and Bagging-BFt(AUC=0.967)models.A comparison between the performance of the models and the models previously reported in the literature confirmed that our ensemble models provided a reliable estimate of flood susceptibilities and their resulting susceptibility maps are trustful for flood early warning systems as well as development of mitigation plans.

关键词： Machine learning Ensemble learners Hybrid modeling

Engineered neuronal microtissue provides exogenous axons for delayed nerve fusion and rapid neuromuscular recovery in rats

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Bioactive Materials 2022年第12期7卷 339-353页

作者： Justin C.Burrell Suradip Das Franco A.Laimo Kritika S.Katiyar Kevin D.Browne Robert B.Shultz Vishal J.tien Phuong t.vu Dmitriy Petrov Zarina SAli Joseph M.Rosen D.Kacy Cullen Center for Brain Injury&Repair Department of NeurosurgeryPerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA Department of Bioengineering School of Engineering&Applied ScienceUniversity of PennsylvaniaPhiladelphiaPAUSA Center for Neurotrauma Neurodegeneration&RestorationCorporal Michael J.Crescenz Veterans Affairs Medical CenterPhiladelphiaPA19104USA Axonova Medical LLCPhiladelphiaPAUSA Dartmouth-Hitchcock Medical Center Division of Plastic SurgeryDartmouth CollegeLebanonNHUSA

Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (tE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. tE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that tE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, tE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). these findings show that tE-NMIs provide the potential to improve functional recovery following delayed nerve repair.

关键词： Nerve regeneration Neuromuscular injury Muscle preservation tissue engineering Microtissue Axon fusion

Hydrogen roles approaching ideal electrical and optical properties for undoped and Al doped ZnO thin films

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Journal of Materiomics 2022年第1期8卷 123-135页

作者： Dung Van Hoang Nam Hoang vu Nga thi Do Anh tuan thanh Pham truong huu Nguyen Jer-Lai Kuo thang Bach Phan Vinh Cao tran Laboratory of Advanced Materials University of ScienceHoChiMinh City700000Viet Nam Vietnam National University HoChiMinh City700000Viet Nam HoChiMinh City Institute of Physics HoChiMinh City700000Viet Nam Institute of Atomic and Molecular Sciences Academia SinicaTaipei10617Taiwan Center for Innovative Materials and Architectures(INOMAR) HoChiMinh City700000Viet Nam Faculty of Materials Science&technology University of ScienceHoChiMinh City700000Viet Nam

this paper distinguished hydrogen roles to improve electron mobility and carrier concentration in ZnO and Al doped ZnO sputtered *** combining experimental evidences and theoretical results,we find out that hydrogen located at oxygen vacancy sites(H_(O))is the main factor gives rise to increase simultaneously mobility and carrier concentration which has not been mentioned *** appropriate hydrogen content during sputtering not only results in crystalline relaxation but also supports doping Al into ZnO,increasing carrier concentration and electron mobility in the *** principles calculations confirmed hydrogen substitutional stability for oxygen vacancy,significantly reducing electron conductivity effective mass and hence increasing electron *** particular,0.8%hydrogen partial pressure ratio achieved 61 cm^(2)V^(-1)s^(-1)maximum electron mobility,optical transmittance above 82%in visible and near-infrared regions,and 2×10^(20) cm^(-3)carrier concentrations for H-Al co-doped ZnO *** values approach ideal electrical and optical properties for transparent conducting oxide *** presence of one maximum electron mobility was attributed to competition between increasing mobility due to restoring effective electron mass and hydrogen passivation of native defects,and decreased electron mobility due to electron-phonon scattering.

关键词： High electron mobility Hydrogen roles Passivation effects Effective electron mass DFt calculations Doped ZnO thin Film

Hydrogeological Characteristics of a Karst Mountainous Catchment in the Northwest of Vietnam

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Acta Geologica Sinica(English Edition) 2001年第3期75卷 260-268页

作者： V.t.tAM t.M.N.vu O.BAtELAAN Research Institute of Geology and Mineral Resources Ministry of Industry VietnamResearch Institute of Geology and Mineral Resources Ministry of Industry VietnamDepartment of Hydrology and Hydraulic Engineering Free University Brussels Belgium

this paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. the catchment is located at 600–700 m a.s.l. and covers an area of 284 km. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including geological and hydrogeological field surveys, cave surveys, dye-tracer tests, meteorological and surface water monitoring. Geological studies and cave surveys have identified the most important active cave/conduit systems within the catchment. Although these data are essential, they are insufficient to make a comprehensive appraisal of the hydrologic nature of the catchment under interest. An attempt was made to calculate a global water balance of the catchment, based on short-term (15 months) meteorological and streamflow records. the results show that, despite the existence of a number of substantial cavern conduit systems, the groundwater system of the catchment is governed by the fracture/fissure matrix. the cavern conduit systems only collect groundwater from the adjacent fracture matrix and/or connect topographically isolated surface watercourses. the groundwater storage of the cavern conduit systems appears to be regionally insignificant in comparison with the governed fracture matrix groundwater system.

关键词： karst hydrology geology lowflow

Research on Subcontractor Risk of EPC Hydropower Project in Vietnam

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World Journal of Engineering and technology 2019年第1期7卷 54-67页

作者： Dinh Bui Sy Hung Mai huu Hai vu Department of Construction Management Can Loc Committee Ha Tinh Vietnam Department of Hydraulic Engineering and Construction National University of Civil Engineering Hanoi Vietnam

Engineering, procurement and construction (EPC) contracts are becoming the most popular form to undertake construction works on large-scale hydropower projects.?the EPC general contractors in Vietnam have been coped with lots of difficulties during the construction phase of hydropower projects, resulting in significant schedule delays and cost overrun. One of the reasons is poor Subcontractors capacity.?In order to overcome above, the current study attempts?to research on identification and control Subcontractors risks of delay process of EPC hydropower project in Vietnam.?through summarizing international research achievements of previous researches relating on EPC hydropower projects combining with analysis characteristics of developing construction of EPC hydropower projects in Vietnam, the current study pointed out all kinds of subcontractor risk of delay process of EPC hydropower project in Vietnam;?a questionnaire with 18 risk elements was designed and then delivered to experts in EPC hydropower project management area. Based on the risk model, 11 main risk elements were identified which can be categorized into 3 groups.?Lastly, the current study proposed suggestions to reduce or avoid risks as well as approach to control risks.?Furthermore, the findings of this study can be a good managerial reference for project management teams who are working in other countries that have similar economic and investment environment to Vietnam to get their EPC construction project completed on schedule, thus ensuring the benefits to the government, the investor, the contractor, and the parties involved.

关键词： EPC Hydropower Project Risk Analysis and Evaluation Risk Control Prevent Risks

the Ellipsoidal Surface Method Solving by Integration for Slope Stability Analysis

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Journal of Geological Resource and Engineering 2016年第2期4卷 89-93页

作者： Sy huu Pham Vinh Phu Pham Minh Le vu thuy loi University Hanoi 100803 Vietnam Delft University of technology Delft 2628 BW the Netherlands technology University of Braunschweig Braunschweig 38448 Germany

Landslide is common phenomena in construction field. Nowadays the cylindrical surface method has been used widely to analyze slope stability. However, this method contains two main disadvantages： firstly, the slip surface is assumed to be in circular shape while in fact it is ellipsoid commonly; and secondly, resolve by difference method causing immensely complicated process due to statically indeterminate equations. In this paper, the authors have presented a method that allows transferring of ellipsoid slip surface to cylindrical shape and carries out a single variable equation （by applying integration method）. Also thanks to this method, the current cylindrical surface method has been proved that its application is proper for man-made slopes but usually inappropriate for natural ones. those results help analysis of slope stability reaching closer to reality.

关键词： Slope stability landslide slice method cylindrical surface method.

Clinical outcomes of patients with chronic hepatitis C after generic direct-acting antiviral treatments in Vietnam: A retrospective analysis

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Asian Pacific Journal of tropical Medicine 2020年第11期13卷 487-493页

作者： Huong tt.vu Azumi Ishizaki Quynh t Nguyen Huyen N Nguyen Hoi t Le Kinh V Nguyen Hiroshi Ichimura National Hospital for tropical Disease HanoiVietnam Department of Viral Infection and International Health Graduate School of Medical SciencesKanazawa UniversityJapan

Objective:to evaluate the outcomes of generic direct-acting antiviral treatments for chronic hepatitis C in ***:the medical records of 522 patients(median 45 years;Female,25.3%)with chronic hepatitis C treated at a tertiary hospital in northern Vietnam in 2016 were retrospectively ***:Female patients were significantly older than male patients(median 52,IQR 41-59 vs.43 years,IQR:39-55;Ptients,49.4%were infected with hepatitis C virus(HCV)genotype 6,followed by 1 a(19.0%),1 b(13.0%),and 3(5.9%).Coinfection with hepatitis B virus or human immunodeficiency virus was noted in 5.8%and 3.1%of patients,*** were treated with ledipasvir/sofosbuvir with or without ribavirin(70.9%),sofosbuvir/pegylated-interferon+ribavirin(13.2%),daclatasvir/sofosbuvir with or without ribavirin(12.5%),or sofosbuvir/ribavirin(3.4%),and 96.4%(n=503)completed the direct-acting antiviral *** patient discontinued treatment due to adverse event(s).A sustained virologic response 12 weeks after the end of the treatment(SVR12)was evaluated in 62.6%of *** sustained virologic response 12 weeks after the end of the treatment was 98.7%regardless of HCV genotypes or direct-acting antiviral *** severity of liver stiffness was significantly decreased from 10.2 to 6.3 kilopascals measured by transient elastography by the treatment(Ptients who completed the directacting antiviral treatment,17.7%returned for further follow-ups after ***:In Vietnam,the current generic direct-acting antiviral treatment for chronic hepatitis C was effective regardless of HCV genotypes and direct-acting antiviral regimens with the attenuation of liver *** is feasible to implement direct-acting antiviral treatment to cure chronic hepatitis C patients at any liver fibrosis stages in Vietnam.

关键词： Vietnam Chronic hepatitis C Generic direct-acting antiviral Improvement of liver stiffness