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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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Forecasting cryptocurrency returns and volume using search engines

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Financial Innovation 2019年第1期5卷 29-41页

作者： Muhammad Ali Nasir Toan Luu duc Huynh Sang Phu nguyen Duy Duong Leeds Beckett University 520 Rose BowlLeeds LS13HBUK University of Economics Ho Chi Minh City Ho Chi Minh CityVietnam Banking University of Ho Chi Minh City Ho Chi Minh CityVietnam

In the context of the debate on the role of cryptocurrencies in the economy as well as their dynamics and forecasting,this brief study analyzes the predictability of Bitcoin volume and returns using Google search *** employed a rich set of established empirical approaches,including a VAR framework,a copulas approach,and non-parametric drawings,to capture a dependence *** a weekly dataset from 2013 to 2017,our key results suggest that the frequency of Google searches leads to positive returns and a surge in Bitcoin trading *** to search values have a positive effect,which persisted for at least a *** findings contribute to the debate on cryptocurrencies/Bitcoins and have profound implications in terms of understanding their dynamics,which are of special interest to investors and economic policymakers.

关键词： Financial innovation Forecasting Blockchain Google search values Bitcoin Cryptocurrencies

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In vivo anticancer activity of maesopsin 4—O— β—glucoside isolated from leaves of Artocarpus tonkinensis *** Gagnep

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Asian Pacific Journal of Tropical Medicine 2016年第4期9卷 343-348页

作者： Trinh Thi Thuy Dao duc Thien Tran Quang Hung nguyen Thanh Tam nguyen Thi Hoang Anh nguyen Thi Nga nguyen Thi Cuc Le Phuong Mai Tran Van Sung Domenico V.Delfino Do Thi Thao Institute of Chemistry.Vietnam Academy of Science and Technology Institute of Biotechnology Vietnam Academy of Science and Technology National Research Council Canada Measurement Science and Standards1200 Montreal RoadBuilding M-12.Ottatca.Ontario KIA OR6 Department of Medicine University of PerugiaPiazzale Gambuli.S.Andrea delle Fratte

Objective:To investigate the antitumor effect of maesopsin 4-O-β-glucoside(TAT2) isolated from the leaves of Artocarpus tonkinensis(***) *** ***:The antitumor activity of TAT2 was evaluated in Lewis lung carcinoma(LLC) tumor-bearing ***/c mice had tumors induced by implantation with 2× 10~6 LLC cells into the subcutaneous right posterior ***-bearing mice were treated orally with a range of doses of TAT2 and a standard drug,*** were observed for tumor growth and mortality *** was collected to determine hematological and biochemical *** TAT2 was isolated from an ethanolic extract of *** *** structure was determined by MS and NMR spectroscopy,and identified as *** compound did not show acute toxicity at the highest dose tested(2 OIK) mg/kg body weight).TAT2 exhibited antitumor activity by decreasing tumor growth,increasing the survival rale,and ameliorating some hematological and biochemical parameters at doses of 100 and 200 mg/kg body weight(P<0.05).Conclusions:These results indicate that TAT2 possesses clear antitumor *** to its bioavailability and low toxicity,and the fact that it could be isolated in a large scale from *** leaves,the compound shows promise as a potential anticancer drug.

关键词： Artocarpus tonkinensis BALB/c Hematological parameters Lewis lung carcinoma Maesopsin 4-0-β-glucoside

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Sea Turtles in Vietnam： On the Edge of Extinction

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Journal of Life Sciences 2015年第8期9卷 356-361页

作者： Cuong The Chu The duc nguyen Institute of Marine Environment and Resources Vietnam Academy of Science and Technology 246-Danang Haiphong Vietnam Department of Ecology Environment and Plant Sciences Stockholm University SE-106 91 Stockholm Sweden

Five species of foraging and breeding sea turtles have been identified in Vietnam, they are Green turtle （Chelonia mydas）, Loggerhead turtle （Caretta caretta）, Olive ridley turtle （Lepidochelys olivacea）, Hawksbill turtle （Eretmochelys imbricata） and Leatherback turtle （Dermochelys coriacea）. Among them, with the exception of Loggerhead turtle （Caretta caretta）, four species have been being lay eggs on the beaches along the country. However, these populations have been strongly suffered by human activities for decades. The number of foraging and breeding Hawksbill and Leatherback sea turtles has dramatically decreased, and Olive Ridley turtle has almost disappeared on their traditional nesting beaches. Beside the reason of harvesting eggs and nesting turtles by catch or by purpose, the developments in coastal areas where sea turtles laying eggs such as in shrimp aquaculture, tourist resort and residential area developments etc., also contributed to this decline of sea turtles. Despite the fact that the recent raising awareness programs on protection and conservation of the sea turtle were very well done with the participation of many organizations and provinces, this important animals still face the risk of extinction in Vietnam.

关键词： Sea turtle nesting foraging, threats.

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Chrysoeriol ameliorates hyperglycemia by regulating the carbohydrate metabolic enzymes in streptozotocin-induced diabetic rats

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Food Science and Human Wellness 2020年第4期9卷 346-354页

作者： Baskaran Krishnan Abirami Ramu Ganesan Ravindran Balasubramani Dinh duc nguyen Soon Woong Chang Shaoyun Wang Jianbo Xiao Balamuralikrishnan Balasubramanian Department of Biochemistry Sree Narayana Guru CollegeCoimbatore641105Tamil NaduIndia Department of Food Science and Home Economics School of Applied SciencesCollege of EngineeringScience and TechnologyFiji National UniversityFiji Islands Department of Environmental Energy and Engineering Kyonggi UniversityYoungtong-GuSuwonGyeonggi-Do16227South Korea College of Biological Science and Technology Fuzhou UniversityFuzhou 350108China International Research Center for Food Nutrition and Safety Jiangsu UniversityZhenjiang 212013China Department of Food Science and Biotechnology College of Life SciencesSejong UniversitySeoul05006South Korea

The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar *** rats were categorized as control,diabetic control supplemented with 0,20 mg/kg chrysoeriol and 600μg/kg BW of glibenclamide for 45-day trial *** results indicated that the inclusion of chrysoeriol(20 mg/kg)showed a significant reduction in plasma glucose,hemoglobin and glycosylated hemoglobin level with a rising of plasma insulin ***,downregulated enzymes including glucose 6-phosphatase,fructose 1,6-bisphosphatase,and glycogen phosphorylase as well upregulated enzymes such as hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,and hepatic glycogen *** was a diminish action found in liver glycogen synthase of tested rat with a rise in gamma-glutamyl transpeptidase,towards normal levels upon treatment with *** histopathological study confirmed that renewal of the beta cells of pancreatic of chrysoeriol and glibenclamide treated *** addition,the molecular docking of chrysoeriol against glycolytic enzymes including hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,using Argus software shows chrysoeriol had greatest ligand binding energy as equivalent to glibenclamide,as a standard ***,chrysoeriol found to be non-toxic with potential regulation on glycemic control and upregulation of the carbohydrate metabolic enzymes.

关键词： Cardiospermum halicacabum Chrysoeriol Anti-hyperglycemic Carbohydrate metabolizing enzymes

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An Energy-Efficient Mobile-Controlled Vertical Handover Management for Real Time Services

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Journal of Computer and Communications 2016年第17期4卷 59-75页

作者： Toan nguyen-duc Eiji Kamioka Graduate School of Engineering and Science Shibaura Institute of Technology Tokyo Japan

Multiple wireless access technology has been embedded into a single mobile device as a fundamental feature, aiming to give end users ubiquitous access at any time. To allow the users to enjoy the ubiquitous connectivity, the mobile device has to consume higher energy for the simultaneous activation of multiple wireless interface and the continuous connectivity. In addition, a seamless vertical handover between the access technologies is a mandatory requirement to insure the quality, reliability and continuity of real time services. In this paper, the continuity of real time services as well as energy saving for mobile devices has been taken into account. The conceptual idea is that whenever traffic rate is lower than a threshold it will be smoothly handed over to a low energy consumption technology, i.e., Bluetooth. When the traffic exceeds the limitation of Bluetooth bandwidth, it will be handed over to a wider bandwidth technology, i.e., Wi-Fi. In the considered scenarios, the technologies are not interconnected;hence, the vertical handover management must be fully controlled by the mobile devices. The performance of the system including energy saving and maintaining the continuity of real time services has been evaluated by direct measurements in a real testbed.

关键词： Energy Efficient Host-Controlled Vertical Handover Bluetooth Wi-Fi SDN Extension Real Time Services

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Technical, Economic and Environmental Evaluation on Mechanical Rice Straw Gathering Method

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Journal of Environmental Science and Engineering(B) 2015年第11期4卷 614-619页

作者： nguyen Thanh Nghi nguyen duc Canh Hau duc Hoa nguyen Van Hung Martin Gummert Center for Agricultural Energy and Machinery Nong Lam University Ho Chi Minh City 700000 Vietnam Crop and Environmental Science Division International Rice Research Institute Metro Manila 1301 Philippines

Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters. High labor cost and lack of labor makes manual collection unfeasible. Farmers therefore often just burn it, which causes pollution, increased greenhouse gas emissions and loss of opportunities to value add. An economic and environmental evaluation and technical field testing of a straw baler with 4 ha/day capacity was therefore conducted in Long An province. During the field testing data on the gathering capacity, fuel consumption, labor requirement and other cost items were collected. The test results showed that the baling cost is US$19.0 per ton of rice straw, the pay-back period of 2. 1 years and the internal rate of return of 38%. In addition to the baling cost, the transportation cost varies from US$24 for a distance of 100 km to US$32 for 150 km. The benefits of the machine are not only economical but also include the reduction of field burning.

关键词： Rice straw gathering technical and economic evaluation environmental benefits.

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Rudder Roll Damping Autopilot Using Dual Extended Kalman Filter–Trained Neural Networks for Ships in Waves

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Journal of Marine Science and Application 2019年第4期18卷 510-521页

作者： Yuanyuan Wang Hung duc nguyen National Center for Maritime Engineering and Hydrodynamics Australian Maritime College University of Tasmania

The roll motions of ships advancing in heavy seas have severe impacts on the safety of crews,vessels,and cargoes;thus,it must be *** study presents the design of a rudder roll damping autopilot by utilizing the dual extended Kalman filter(DEKF)trained radial basis function neural networks(RBFNN)for the surface *** autopilot system constitutes the roll reduction controller and the yaw motion controller implemented in *** analyzing the advantages of the DEKF-trained RBFNN control method theoretically,the ship’s nonlinear model with environmental disturbances was employed to verify the performance of the proposed stabilization *** sailing scenarios were conducted to investigate the motion responses of the ship in *** results demonstrate that the DEKF RBFNN based control system is efficient and practical in reducing roll motions and following the path for the ship sailing in waves only through rudder actions.

关键词： Rudder roll damping Autopilot Radial basis function Neural networks Dual extended Kalman filter training Intelligent control Path following Advancing in waves

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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

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Backward Dijkstra Algorithms for Finding the Departure Time Based on the Specified Arrival Time for Real-Life Time-Dependent Networks

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Journal of Applied Mathematics and Physics 2016年第1期4卷 1-7页

作者： Gelareh Bakhtyar Vi nguyen Mecit Cetin duc nguyen Department of Civil and Environmental Engineering Old Dominion University Norfolk USA Department of Mechanical and Aerospace Engineering Old Dominion University Norfolk VA USA Department of Modeling Simulation and Visualization Engineering Old Dominion University Norfolk VA USA

A practical transportation problem for finding the “departure” time at “all source nodes” in order to arrive at “some destination nodes” at specified time for both FIFO (i.e., First In First Out) and Non-FIFO “Dynamic ” Networks is considered in this study. Although shortest path (SP) for dynamic networks have been studied/documented by various researchers, contributions from this present work consists of a sparse matrix storage scheme for efficiently storing large scale sparse network’s connectivity, a concept of Time Delay Factor (TDF) combining with a “general piece- wise linear function” to describe the link cost as a function of time for Non-FIFO links’ costs, and Backward Dijkstra SP Algorithm with simple heuristic rules for rejecting unwanted solutions during the backward search algorithm. Both small-scale (academic) networks as well as large- scale (real-life) networks are investigated in this work to explain and validate the proposed dynamic algorithms. Numerical results obtained from this research work have indicated that the newly proposed dynamic algorithm is reliable, and efficient. Based on the numerical results, the calculated departure time at the source node(s), for a given/specified arrival time at the destination node(s), can be non-unique, for some Non-FIFO networks’ connectivity.

关键词： Backward Dijkstra Dynamic Networks Piece-Wise Linear Function Specified Arrival Time

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