检索结果-南通市图书馆

IEEE/CAA Journal of Automatica Sinica 2021年第11期8卷 1786-1799页

作者： van nhan vo Hung Tran Chakchai So-In Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Faculty of Information Technology Duy Tan UniversityDa Nang 550000Vietnam Applied Network Technology Laboratory Department of Computer ScienceFaculty of ScienceKhon Kaen UniversityKhon Kaen 40002Thailand Faculty of Computer Science Phenikaa UniversityHanoi 100000Vietnam

In this paper,the detection capabilities and system performance of an energy harvesting(EH)Internet of Things(Io T)architecture in the presence of an unmanned aerial vehicle(UAV)eavesdropper(UE)are *** communication protocol is divided into two *** the first phase,a UAV relay(UR)cooperates with a friendly UAV jammer(UJ)to detect the UE,and the UR and UJ harvest energy from a power beacon(PB).In the second phase,a ground base station(GBS)sends a confidential signal to the UR using non-orthogonal multiple access(NOMA);the UR then uses its harvested energy to forward this confidential signal to IoT destinations(IDs)using the decode-and-forward(DF)***,the UJ uses its harvested energy to emit an artificial signal to combat the detected UE.A closed-form expression for the probability of detecting the UE(the detection probability,DP)is derived to analyze the detection ***,the intercept probability(IP)and throughput of the considered IoT architecture are ***,we identify the optimal altitudes for the UR and UJ to enhance the system and secrecy *** Carlo simulations are employed to verify our approach.

关键词： Detection probability(DP) energy harvesting(EH) friendly UAV jammer Internet of Things(IoT) system performance UAV detection

On the System Performance of Mobile Edge Computing in an Uplink NOMA WSN With a Multiantenna Access Point Over Nakagami-m Fading

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第4期9卷 668-685页

作者： van-Truong Truong van nhan vo Dac-Binh Ha Chakchai So-In the Faculty of Electrical-Electronic Engineering Duy Tan University the Institute of Research and Development Duy Tan University the Faculty of Information Technology Duy Tan University IEEE the Applied Network Technology(ANT)Laboratory Department of Computer ScienceCollege of ComputingKhon Kaen University

In this paper,we study the system performance of mobile edge computing(MEC)wireless sensor networks(WSNs)using a multiantenna access point(AP)and two sensor clusters based on uplink nonorthogonal multiple access(NOMA).Due to limited computation and energy resources,the cluster heads(CHs)offload their tasks to a multiantenna AP over Nakagami-m *** proposed a combination protocol for NOMA-MEC-WSNs in which the AP selects either selection combining(SC)or maximal ratio combining(MRC)and each cluster selects a CH to participate in the communication process by employing the sensor node(SN)*** derive the closed-form exact expressions of the successful computation probability(SCP)to evaluate the system performance with the latency and energy consumption constraints of the considered *** results are provided to gain insight into the system performance in terms of the SCP based on system parameters such as the number of AP antennas,number of SNs in each cluster,task length,working frequency,offloading ratio,and transmit power ***,to determine the optimal resource parameters,i.e.,the offloading ratio,power allocation of the two CHs,and MEC AP resources,we proposed two algorithms to achieve the best system *** approach reveals that the optimal parameters with different schemes significantly improve SCP compared to other similar *** use Monte Carlo simulations to confirm the validity of our analysis.

关键词： Mobile edge computing(MEC) Nakagami-m fading offloading selection combining(SC)/maximal ratio combining(MRC) successful computation probability(SCP) uplink nonortho-gonal multiple access(NOMA) wireless sensor networks(WSNs)

Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate element (CS-MIN3)

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2019年第2期13卷 251-272页

作者： nhan NGUYEN-MINH Nha TRAN-van Thang BUI-XUAN Trung NGUYEN-THOI Faculty of Applied Science Bach Khoa University (BKU)Ho Chi Minh CityVietnam Faculty of Mathematics and Computer Science Ho Chi Minh City University of Science (HCMUS)Ho Chi Minh CityVietnam Department of Mathematics L ouisiana State UniversityBaton RougeLA 70803USA Division of Computational Mathematics and Engineering Institute of Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Many homogenization models for corrugated panels of different shapes have been proposed. However, there is a lack of investigations for verifying their accuracy and reliability. In addition, in the recent trend of development of smoothed finite element methods, the cell-based smoothed three-node Mindlin plate element (CS-MIN3) based on the first-order shear deformation theory (FSDT) has been proposed and successfully applied to many analyses of plate and shell structures. Thus, this paper further extends the CS-MIN3 by integrating itself with homogenization models to give homogenization methods. In these methods, the equivalent extensional, bending, and transverse shear stiftriess components which constitute the equivalent orthotropic plate models are represented in explicit analytical expressions. Using the results of ANSYS and ABAQUS shell simulations as references, some numerical examples are conducted to verify the accuracy and reliability of the homogenization methods for static analyses of trapezoidally and sinusoidally corrugated panels.

关键词： homogenization corrugated panel asymptotic analysis smoothed finite element method (S-FEM) cell-based smoothed three-node Mindlin plate element (CS-MIN3)

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Research on stability of laminated composite plate under nonlinear aerodynamic load

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2023年第4期13卷 320-328页

作者： The van Tran Quoc Hoa Pham nhan Thinh Hoang Faculty of Mechanical Engineering Industrial University of Ho Chi Minh CityHo Chi Minh City 700000Vietnam Tran Dai Nghia University Ho Chi Minh City700000Vietnam Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam

In this paper,we propose an finite element approach based on classical plate theory to investigate the dynamic stability of a layered composite plate subject to nonlinear aerodynamic *** study considers the influence of temperature,nonlinear geometry,and nonlinear aerodynamic load on composite plate structures ***,the present work conduct comparison the results of the critical pressure value between the nonlinear aerodynamic load and the linear aerodynamic load,thereby pointing out some necessary cases which must consider the nonlinearity of aerodynamic load for calculating the aerospace *** determine the critical pressure value and vibrational amplitude response of the plate by means of *** outcomes of our calculations can be useful in designing and repairing body shells and wings of aircraft equipment.

关键词： Finite element approach Nonlinear aerodynamic load Composite plate

Adaptive Nonlinear PD Controller of Two-Wheeled Self-Balancing Robot with External Force

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第11期81卷 2337-2356页

作者： van-Truong Nguyen Dai-nhan Duong Dinh-Hieu Phan Thanh-Lam Bui Xiem Hoangvan Phan Xuan Tan Faculty of Mechatronics SMAEHanoi University of IndustryHanoi159999Vietnam Faculty of Electronics and Telecommunications Vietnam National University-University of Engineering and Technology(VNU-UET)Hanoi10000Vietnam College of Engineering Shibaura Institute of TechnologyTokyo135-8548Japan

This paper proposes an adaptive nonlinear proportional-derivative(ANPD)controller for a two-wheeled self-balancing robot(TWSB)modeled by the Lagrange equation with external *** proposed control scheme is designed based on the combination of a nonlinear proportional-derivative(NPD)controller and a genetic algorithm,in which the proportional-derivative(PD)parameters are updated online based on the tracking error and the preset error *** addition,the genetic algorithm is employed to adaptively select initial controller parameters,contributing to system stability and improved control *** proposed controller is basic in design yet simple to *** ANPD controller has the advantage of being computationally lightweight and providing high robustness against external *** stability of the closed-loop system is rigorously analyzed and verified using Lyapunov theory,providing theoretical assurance of its *** and experimental results show that the TWSB robot with the proposed ANPD controller achieves quick balance and tracks target values with very small errors,demonstrating the effectiveness and performance of the proposed *** proposed ANPD controller demonstrates significant improvements in balancing and tracking performance for two-wheeled self-balancing robots,which has great applicability in the field of robot control *** represents a promising solution for applications requiring precise and stable motion control under varying external conditions.

关键词： Two-wheeled self-balancing robot nonlinear PD control external force genetic algorithm

Mobilization of Arsenic in Groundwater in the Southern Hanoi City (Vietnam) as Studied by Isotopic and Related Techniques

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Protection 2013年第7期4卷 68-74页

作者： Dang Duc nhan Doan van Canh Pham Quy nhan Nguyen Thi Thanh Thuy Dinh Thi Bich Lieu vo Thi Anh Dang Anh Minh Center for Water Resources Management Hanoi Vietnam Hanoi University of Mining and Geology Hanoi Vietnam Institute for Nuclear Science and Technology Hanoi Vietnam Vietnam Association of Hydrogeology Hanoi Vietnam Vietnam Atomic Energy Institute Hanoi Vietnam

Sixteen samples of surface and groundwater from the most southern part of the Hanoi city (Vietnam) has been taken and analyzed for the soluble major ions, namely Na+, K+, , Ca2+, Mg2+, Cl-, , and arsenic as well as molybdenum content along with isotopic composition of deuterium and oxygen (δ2H and δ18O), tritium activity, and δ13C in DIC. The stable isotopic composition of groundwater indicates the water in that area is recharged from the local meteoric and theRed River’s water sources. The mean residence time of the groundwater should be before 60-ies of the past century as its 3H activity ranged from LOD of the analytical technique (0.4 TU) to 2.1 TU only implying that As would not be related to its recent application. The concentrations of As in the water samples is weakly correlated with those of Fe2+ (R2 = 0.08) but it strongly did with the concentrations of bicarbonate (R2 = 0.80). Thus, bicarbonate seems to liberate As adsorbed on hydrous ferric oxides (Hfo) into water through the displacement mechanism. The surface adsorption-desorption of As could be proven by a strong correlation between As and Mo concentrations (R2 = 0.77). The bicarbonate formation in groundwater was thought to be, partly, due to the bio-mineralization of natural organic matter (NOM) by bacteria followed by the dissolution of calcite and/or dolomite present in the sediments. Evidence for the NOM bio-mineralization was found in the close relationship between δ13C and the concentration of bicarbonate in water. Therefore, the mobilization of As in groundwater of bicarbonate type in the southern part of Hanoi city seems to be not only due to the reductive dissolution of the Hfo but the bicarbonate displacement also should be considered.

关键词： Arsenic Mobilization Isotopic Technique Groundwater Nom Bio-Mineralization As-Bicarbonate Displacement

Anti-inflammatory effects of Solanum procumbens on a low dose complete Freund's adjuvant-induced arthritis rat model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2023年第5期13卷 214-221页

作者： Xuan-Hai Do Trong Nghia Nguyen Thanh Chung Dang Thi Thanh Mai Nguyen Trung nhan Nguyen van Nhat Truong Do Huu Tho Le Xuan Hai Nguyen Hoang Phu Dang Giang-Linh Nguyen Dinh-Khanh Hoang van-Quan Le van-Mao Can Department of Practical and Experimental Surgery Vietnam Military Medical UniversityHanoi 10000Vietnam Department of Reconstructive and Microsurgery Craniofacial and Reconstructive Surgery CentreMilitary Central Hospital 108Hanoi 10000Vietnam Department of Anatomic Pathology Military Hospital 103Vietnam Military Medical UniversityHanoi 10000Vietnam Faculty of Chemistry University of ScienceVietnam National University Ho Chi Minh CityHo Chi Minh City 70000Vietnam Faculty of Medicine University of Medicine and PharmacyVietnam National UniversityHanoi 10000Vietnam Department of Ultrasound Imaging Diagnostics CentreMilitary Hospital 103Vietnam Military Medical UniversityHanoi 10000Vietnam Department of Functional Diagnostics Military Hospital 103Vietnam Military Medical UniversityHanoi 10000Vietnam Department of Pathophysiology Vietnam Military Medical UniversityHanoi 10000Vietnam

Objective:To investigate the anti-inflammatory and analgesic effects of Solanum procumbens on complete Freund’s adjuvantinduced arthritis rat ***:We isolated and identified five compounds in the ethanolsoluble Solanum procumbens extract(SP)with anti-inflammatory effects,including ursolic acid,β-sitosterol,hexadecanoic acid,cisvaccenic acid,and vanillic ***,we investigated the anti-inflammatory effects of SP on rheumatoid arthritis symptoms,including paw volumes,local temperatures,withdrawal latency,and mechanical withdrawal threshold at the hind paw and white blood cell(WBC)number from complete Freund’s adjuvant-induced arthritis rat ***:We have successfully established a complete Freund’s adjuvant-induced arthritis rat model at a low dose(1 mg/mL).SP extract significantly reduced paw volumes(P<0.05),prolonged withdrawal latencies(P<0.05),decreased local temperature,and increased the mechanical withdrawal threshold(P<0.05),but only SP extract at the dose of 300 mg/kg significantly decreased WBC ***:SP extract could be a potential medication candidate with anti-inflammatory effects for arthritis,but it requires further investigation into the mechanism of the SP and its effectiveness on other models as well as clinical trials.

关键词： Solanum procumbens Arthritis Anti-inflammation Complete Freund's adjuvant Rats

The Effects of Nutritional Media and Initial Cell Density on the Growth and Development of Spirulina platensis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Agricultural Science and Technology(A) 2017年第B10期7卷 60-67页

作者： Nguyen van Khanh Nguyen Thi Diem Le Thi Tuyet nhan Phan van Cu Tran Quang Khanh van Ngo Thi Hoan Institute of Biotechnology Hue UniversityPhu ThuongPhu VangThua Thien Hue 530000Vietnam Faculty of Fisheries University of Agriculture and ForestryHue University102 Phung Hung StreetHue 530000Vietnam Faculty of Fisheries Ha Long University258 Bach Dang StreetUong Bi City 207900Quang NinhVietnam

The main objective of the study was to determine the effects of nutritional media and initial cell density on the growth and development of Spirulina *** study was carried out at the Center for Incubation and Technology Transfer,Hue University from May 2015 to August *** the first experiment,*** was cultured in four different nutritional media,including Zarrouk,Spi-RIA3,Nisole and Thuoc medium(Vietnamese).Resulted showed that *** grew significantly in the Zarrouk medium rather than in other nutritional medium at the same time,and gained the maximum density of 2,736.5 mg/L after 13 d inoculums,with specific growth rate of 4.987%per day and the time to doubling population of 0.139 *** the second experiment,*** was cultured in six different initial cell densities:100,400,700,1,000,1,300 and 1,600 mg/L,and the optimum nutritional medium was Zarrouk medium selected from experiment *** showed at the initial culture density of 400 mg/L,the highest biomass was gained with the maximum density of 3,071.2 mg/L after 21 d inoculums,with specific growth rate of 9.15%per day and time to double population of 0.076 *** biomass from culture in Zarrouk medium at initial cell density 400 mg/L obtained total protein of 51.98%,total lipid of 1.75%,total carbohydrate of 0.75%,carotene of 0.36%and total minerals of 5.2%,on a basis of dry matter.

关键词： Spirulina platensis nutrient medium initial density growth rates

Genesis and Quality of Groundwater in the Southeastern Region of Southern Vietnam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(A) 2017年第6期6卷 277-292页

作者： Chau Tran Vinh Tran Hong Thai Doan van Canh Dang Due nhan Nguyen Cao Huan Nguyen van Nghia Nguyen Hong Hieu Trinh Thi Thu van Department of Water Resources Management Ministry of Natural Resources and Environment Hanoi 100000 Vietnam National Meteorological and Hydrological Center Hanoi 100000 Viemam Hydrogeology Assoeiation of Vietnam Hanoi 100000 Vietnam Department of Geology Hanoi University of Natural Sciences Hanoi 100000 Vietnam

The origin and quality of groundwater in the Southeastern region （belongs to Southern Plain） were identified by using isotopic techniques and geochemical analysis. Groundwater samples were collected from 7 aquifers： the Holocene, upper Pleistocene, middle Pleistocene, lower Pleistocene, upper Pliocene, middle Pliocene and Miocene aquifers. The water isotopic compositions （82H and 8180） were determined to elucidate the origin and the interaction between surface water and groundwater studies. Transit time （age） of the groundwater samples was determined to explain the direction of groundwater flow. The dating techniques included 3H and ^14C isotopes measurement, followed by a correction for the initial ^14C-activity by the ^13C-composition （^13C） in TDIC （Total Dissolved Inorganic Carbon）. Geochemical parameters of the groundwater samples were measured either directly in the field or in the laboratory. The results showed that the groundwater from the Holocene and upper Pleistocene aquifers was most recharged from the local meteorological and hydrological systems, including local precipitation, fiver and reservoirs. Thus, it has short transit time and its stable isotopic composition is spread around the local meteoric waterline and lines for rivers or reservoirs water. The groundwater in the deeper aquifers： middle and lower Pleistocene, and Neogene aquifers has old age up to 22.5 ka BP. Its water seems to be recharged from the areas with an altitude from 600 to 700 m higher to the Neogene deposit layer altitude. The groundwater in the SE SP （South-Eastern Southern Plain） region has a high quality. The water type is Na-Ca-Mg-HCO3 with low content of chloride and TDS （Total Dissolved Solids）. Calcite/dolomite and gypsum dissolution, organic matter decomposition and sequence of red-ox reactions proceeding through different electron acceptors sediment were controlled the chemistry of the groundwater in the study region.

关键词： Water isotopic composition ^14C-dating groundwater South-Eastern Southern Plain region Vietnam.