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Effect of Fabrication Process on the Hydrophilic Properties of Porous TiO2 thin Films for Self-Cleaning Application

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材料科学与工程（中英文B版） 2016年第3期6卷 126-130页

作者： nguyen thi mai Huong nguyen thanh Binh Le thi Thu Huong nguyen Dinh Dung nguyen Trong Tinh Institute of Applied Physics and Scientific Instruments Vietnam Academy of Science and Technology Cau Giay Dist Hanoi Vietnam

A Truck Scheduling Problem for Multi-Crossdocking System with Metaheuristics

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Computers, Materials & Continua 2022年第9期72卷 5165-5178页

作者： Phan nguyen Ky Phuc nguyen Van thanh Duong Bao Tram International University-Vietnam National University Vietnam National UniversityHoChiMinh City70000Vietnam Faculty of Commerce Van Lang UniversityHo Chi Minh City70000Vietnam

The cross-docking is a very important subject in logistics and supply chain *** to the definition,cross-docking is a process dealing with transhipping inventory,in which goods and products are unloaded from an inbound truck and process through a flow-center to be directly loaded onto an outbound ***-docking is favored due to its advantages in reducing the material handing cost,the needs to store the product in warehouse,as well decreasing the labor cost by eliminating packaging,storing,pick-location and order *** cross-docking,products can be consolidated and transported as a full load,reducing overall distribution *** this paper,we focus on a truck scheduling at the multidoor,multi-crossdocking network with inventory constraints and process capability *** this model,a truck can visit severals docks for loading or unloading many types *** situation is very common in *** study also developed an exact mathematical model using mixedinteger linear programming(MILP)with the objective of minimizing the makespan to obtaint the benchmark in small scale *** scale problems are solved through Simulated Annealing(SA)algorithm and Tabu Search(TS)*** of these algorithms will be compared to benchmarks obtained from solver as well as to each other.

关键词： Truck scheduling multi-door multi-crossdocking network simulated annealing tabu search

Beach Profiles Characteristics Along Giao Thuy and Hai Hau Coasts,Vietnam:A Field Study

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China Ocean Engineering 2012年第4期26卷 699-712页

作者： nguyen Viet thanh 郑金海张弛 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore Engineering Hohai University Faculty of Civil Engineering University of Transport and Communications

Giao Thuy and Hai Hau coasts are located in Nam Dinh province, Vietnam, with a total coastline of 54.42 km in length. The sea-dike system has been seriously damaged and there have been many dike breaches which caused floods and losses. this situation is considered of a general representative for coastal area in the northern part of Vietnam. A variety of studies have shown that the gradient in the longshore sediment transport rate and the offshore fine sediment lost are the main mechanisms causing the beach erosion. this study presents a field investigation of the beach profiles at Giao Thuy and Hai Hau beaches. Three types of empirical functions for the equilibrium beach profile are applied and compared with the observations. Results show that all observed beach profiles can be described by a single function. However, one specific equilibrium profile equation is not sufficient to assess all beach profiles. In Section 1 of Giao Thuy and Section 3 of Hai thinh beaches, beach profiles are consistent with the logarithmic function, while the exponential function fits well in Section 2. this difference is explained with respect to coastal morphology, sediment characteristics and hydrodynamic conditions which vary in site. An analysis of the validity of the beach profile functions is recommended for the numerical modeling and engineering designs in this area.

关键词： beach profile field study power function exponential function logarithmic function

OPT-BAG Model for Predicting Student Employability

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Computers, Materials & Continua 2023年第8期76卷 1555-1568页

作者： Minh-thanh Vo Trang nguyen Tuong Le Faculty of Information Technology HUTECH UniversityHo Chi Minh CityVietnam Faculty of Information Technology Ho Chi Minh City Open UniversityHo Chi Minh CityVietnam Laboratory for Artificial Intelligence Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh CityVietnam Faculty of Information Technology School of TechnologyVan Lang UniversityHo Chi Minh CityVietnam

The use of machine learning to predict student employability is important in order to analyse a student’s capability to get a *** on the results of this type of analysis,university managers can improve the employability of their students,which can help in attracting students in the *** addition,learners can focus on the essential skills identified through this analysis during their studies,to increase their *** effectivemethod calledOPT-BAG(OPTimisation of BAGging classifiers)was therefore developed to model the problem of predicting the employability of *** model can help predict the employability of students based on their competencies and can reveal weaknesses that need to be ***,we analyse the relationships between several variables and the outcome variable using a correlation heatmap for a student employability ***,a standard scaler function is applied in the preprocessing module to normalise the variables in the student employability *** training set is then input to our model to identify the optimal parameters for the bagging classifier using a grid search cross-validation ***,the OPT-BAG model,based on a bagging classifier with optimal parameters found in the previous step,is trained on the training dataset to predict student *** empirical outcomes in terms of accuracy,precision,recall,and F1 indicate that the OPT-BAG approach outperforms other cutting-edge machine learning models in terms of predicting student *** this study,we also analyse the factors affecting the recruitment process of employers,and find that general appearance,mental alertness,and communication skills are the most *** indicates that educational institutions should focus on these factors during the learning process to improve student employability.

关键词： Ensemble classifier grid search cross-validation OPT-BAG student employability

Spatiotemporal Trend Analysis of Precipitation Extremes in Ho Chi Minh City, Vietnam During 1980–2017

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International Journal of Disaster Risk Science 2021年第1期12卷 131-146页

作者： nguyen Trong Quan Dao nguyen Khoi nguyen Xuan Hoan nguyen Ky Phung thanh Duc Dang Faculty of Environmental and Food Engineering Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam Faculty of Environment University of ScienceHo Chi Minh City 700000Vietnam Vietnam National University Ho Chi Minh City 700000Vietnam Ho Chi Minh City University of Food Industry Ho Chi Minh City 700000Vietnam Institute for Computational Science and Technology Ho Chi Minh City 700000Vietnam Engineering Systems and Design Pillar Singapore University of Technology and DesignTampines 487372Singapore

In this study,the spatiotemporal variability of trends in extreme precipitation events in Ho Chi Minh City during the period 1980–2017 was analyzed based on several core extreme precipitation indices(Rx1 day,Rx5 day,CDD,CWD,R20 mm,R25 mm,R95 p,and SDII).The nonparametric Mann–Kendall and Sen’s slope methods were used to compute the statistical strength,stability,and magnitude of trends in annual rainfall,as well as the extreme precipitation *** found that 64%of the stations had statistically significant upward trends in yearly rainfall,with high magnitudes frequently observed in the northern and southern regions of the *** the extreme precipitation indices,only SDII and R25 mm showed dominantly significant ***,there were increasing trends in the frequency and duration at the southern and central regions of the city during the study ***,El Ni?o-Southern Oscillation and Pacific Decadal Oscillation positively correlated with the duration and negatively correlated with the intensity and frequency of extreme ***,water management plans should be adjusted appropriately to reduce the severe impacts of precipitation extremes on communities and ecosystems.

关键词： Spatiotemporal trend Extreme precipitation Extreme precipitation indices Ho Chi Minh City

The effect of a curved bed on the discharge equation in a spillway with a breast wall

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Journal of Hydrodynamics 2015年第2期27卷 311-318页

作者： nguyen Cong-thanh 王玲玲唐洪武 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering College of Water Conservancy and Hydropower Engineering Hohai University

The flow through a breast wall spillway is greatly affected by the centripetal force due to a downstream curved profile. Therefore, the mean vertical pressure distribution at the outlet section is not consistent with the hydrostatic pressure law. this distribution in turn affects the discharge capacity of the breast wall spillway. this paper experimentally studies the effect of a convex downstream profile on the mean pressure variation and the discharge of a breast wall spillway without gates. It is indicated that the effect of the curvilinear streamline on the mean vertical pressure variation is significant. The regression analysis method is used to determine the water head effect Z o of the orifice opening through the mean pressure variation. A discharge prediction formula of the breast wall spillway is obtained under the limited conditions of a laboratory flume. The predicted discharge is compared to the measured discharge. A good agreement is evidenced for the free orifice flow with errors within ？5%, while a big error（20% or even more） is obtained if the hydrostatic pressure law is used for the determination of Zo.

关键词： curved bed spillway breast wall multiple linear regression orifice flow mean pressure distribution

Parity 3 or More at Haiphong Hospital of Obstetrics and Gynecology in 2016

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Journal of Health Science 2018年第2期6卷 91-99页

作者： nguyen thi mai Phuong Haiphong University of Medicine and Pharmacy Hai Phong 180000 Viet Nam

Background： Although increasing parity increased the risk of pregnancy complications and despite of Vietnam’s family planning policy of two-child, the percent of women having three or more children has tended for five years. Objectives：（1） Find out the prevalence of parity ≥ 3 and their reasons at Haiphong Hospital of Obstetrics and Gynecology in 2016; （2） Describe the methods of labor and its adverse outcomes. Materials and methods： A cross-sectional in 485 women had delivered three or more infants at Haiphong Hospital of Obstetrics and Gynecology from June to August, 2016. Results： The prevalence of parity ≥ 3 is 11.9%, no relation to geopraphy, education and career. The main reasons are unplanned pregnancy and desire to have a baby boy. The sex ratio at birth is 162. The proportion of cesarean delivery is 53.4%, in which is due to an old C-section. Conclusion： serious gender is imbalance among women having three or more baby （162 baby boys per hundred baby girls）.

关键词： Parity 3 or more sex ratio at birth Haiphong Hospital of Obstetrics and Gynecology.

Modelling and Numerical Valuation of Power Derivatives in Energy Markets

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Advances in Applied Mathematics and Mechanics 2012年第3期4卷 259-293页

作者： mai Huong nguyen Matthias Ehrhardt Institut fur Mathematik Technische Universitat BerlinStrasse des 17.Juni 13610623 BerlinGermany Lehrstuhl fur Angewandte Mathematik und Numerische Analysis Fachbereich C-Mathematik und NaturwissenschaftenBergische Universitat WuppertalGaußstr.2042119 WuppertalGermany

In this work we investigate the pricing of swing options in a model where the underlying asset follows a jump diffusion *** focus on the derivation of the partial integro-differential equation(PIDE)which will be applied to swing contracts and construct a novel pay-off function from a tree-based pay-off matrix that can be used as initial condition in the PIDE *** valuing swing type derivatives we develop a theta implicit-explicit finite difference scheme to discretize the PIDE using a Gaussian quadrature method for the integral *** on known results for the classical theta-method the existence and uniqueness of solution to the new implicit-explicit finite difference method is *** numerical examples illustrate the usability of the proposed method and allow us to analyse the sensitivity of swing options with respect to model *** particular the effects of number of exercise rights,jump intensities and dividend yields will be investigated in depth.

关键词： Swing options jump-diffusion process mean-reverting Black-Scholes equation energy market partial integro-differential equation theta-method Implicit-Explicit-Scheme

Adaptive Relaying Protocol for Decode and Forward Full-Duplex System over Rician Fading Channel: System Performance Analysis

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China Communications 2019年第3期16卷 92-102页

作者： Tan N.nguyen Minh Tran thanh-Long nguyen Miroslav Voznak Wireless Communications Research Group Faculty of Electrical and Electronics Engineering Ton Duc Thang University Optoelectronics Research Group Faculty of Electrical and Electronics Engineering Ton Duc Thang University Center for Information Technology Ho Chi Minh City University of Food Industry Faculty of Electrical Engineering and Computer Science VSB-Technical University of Ostrava

In this paper, the system performance of a decode-and-forward(DF) full-duplex(FD) adaptive relaying network over the Rician fading environment is proposed, analyzed and demonstrated. In the first stage, the system is presented with the energy harvesting and information transmission processes. After that, the analytical expressions of the achievable throughput, the outage probability, and symbol error ratio(SER) were proposed, analyzed and demonstrated. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions in the influence of the key system parameters. The results show that the analytical and simulated results match for all possible parameter values.

关键词： relaying network throughput outage probability SER wireless energy harvesting(EH)