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On the Multiplicity and the Cohen-Macaulayness of Fiber Cones of Graded Modules

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Algebra Colloquium 2021年第1期28卷 13-32页

作者： nguyen Tien manh Department of Mathematics Hung Vuong University Nguyen Tat Thanh StreetViet Tri CityPhu ThoVietnam

Let(A,m)be a Noetherian local ring with maximal ideal m,I an ideal of A,J an m-primary ideal of A,N a finitely generated A-module,S=■n≥0 Sn a finitely generated standard graded algebra over A and M=■n≥0 Mn a finitely generated graded *** characterize the multiplicity and the Cohen-Macaulayness of the fiber cone F(M)=■n≥0 Mn/JM_(n).As an application,we obtain some results on the multiplicity and the Cohen--Macaulayness of the fiber cone■n≥0 I^(n)N/JI^(n)N.

关键词： (FC)-sequence filter-regular sequence multiplicity Cohen-Macaulay fiber cone

A study on flow fields and performance of water wheel turbine using experimental and numerical analyses

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Science China(Technological Sciences) 2018年第3期61卷 464-474页

作者： nguyen manh Hung JEONG Haechang YANG Changjo Graduate School Division of Marine Engineering Mokpo National Maritime University Department of Marine Engineering Mokpo National Maritime University

In this paper, an analysis of the performance and flow fields of water wheel turbines for tidal energy extraction is carried out using experimental and numerical methods. The purpose of this work is to develop a water turbine suitable for sites, where fast and shallow surface flows are available, such as rivers or tidal currents. For both methods, the water wheel turbine is tested over a range of tip speed ratios with a differing number of rotor blades, ranging between three and twelve. The results indicate that the numerical simulation shows agreement with the experiment in most cases. Also, the water wheel turbine operates effectively at a range of small tip-speed ratios, where the highest turbine efficiency is produced. Under the same working conditions, the turbines using between six and nine blades generate a greater efficiency and cause lesser reverse flows than others when submerged in water. In contrast, the 3-bladed turbine is the least efficient design as it produces the lowest amount of energy and causes intense vibrations and noises. These noises are a result of a collision between the incoming flow of the channel and the wheel blades during the experimentation, especially at high load conditions. By adding more blades, the torque generated is improved considerably; however, the upstream and downstream depths of the turbine, in this case, are also elevated ***, in the inlet region, the 3-bladed and 6-bladed turbines have a smaller shock loss and a lower resistance to the main flow from the inlet than the others. Meanwhile, it is found that the flow in the outlet region on the turbines with between nine and twelve blades is in the opposite direction to the wheel's rotation, significantly obstructing the main flow from the inlet.

关键词： water wheel tidal energy tip speed ratio the number of blades

Combining Entropy Optimization and Sobel Operator for Medical Image Fusion

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Computer Systems Science & Engineering 2023年第1期44卷 535-544页

作者： nguyen Tu Trung Tran Thi Ngan Tran manh Tuan To Huu nguyen Faculty of Computer Science and Engineering Thuyloi University175 Tay SonDong DaHanoi010000Vietnam University of Information and Communication Technology Thai Nguyen UniversityThai Nguyen240000Vietnam

Fusing medical images is a topic of interest in processing medical *** is achieved to through fusing information from multimodality images for the purpose of increasing the clinical diagnosis *** fusion aims to improve the image quality and preserve the specific *** methods of medical image fusion generally use knowledge in many differentfields such as clinical medicine,computer vision,digital imaging,machine learning,pattern recognition to fuse different medical *** are two main approaches in fusing image,including spatial domain approach and transform domain *** paper proposes a new algorithm to fusion multimodal *** algorithm is based on Entropy optimization and the Sobel *** transform is used to split the input images into components over the low and high frequency ***,two fusion rules are used for obtaining the fusing *** rule,based on the Sobel operator,is used for high frequency *** second rule,based on Entropy optimization by using Particle Swarm Optimization(PSO)algorithm,is used for low frequency *** algorithm is implemented on the images related to central nervous system *** experimental results of the paper show that the proposed algorithm is better than some recent methods in term of brightness level,the contrast,the entropy,the gradient and visual informationfidelity for fusion(VIFF),Feature Mutual Information(FMI)indices.

关键词： Medical image fusion wavelet entropy optimization PSO Sobel operator

Optimum Design for the Magnification Mechanisms Employing Fuzzy Logic-ANFIS

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Computers, Materials & Continua 2022年第12期73卷 5961-5983页

作者： Ngoc Thai Huynh Tien V.T.nguyen Quoc manh nguyen Faculty of Automobile Technology Industrial University of Ho Chi Minh CityHo Chi Minh City70000Vietnam Faculty of Mechanical Technology Industrial University of Ho Chi Minh CityHo Chi Minh City70000Vietnam Faculty of Mechanical Engineering Hung Yen University of Technology and EducationHung Yen160000Vietnam

To achieve high work performance for compliant mechanisms of motion scope,continuous work condition,and high frequency,we propose a new hybrid algorithm that could be applied to multi-objective optimum *** this investigation,we use the tools of finite element analysis(FEA)for a magnificationmechanism to find out the effects of design variables on the magnification ratio of the mechanism and then select an optimal mechanism that could meet design requirements.A poly-algorithm including the Grey-Taguchi method,fuzzy logic system,and adaptive neuro-fuzzy inference system(ANFIS)algorithm,was utilized mainly in this *** FEA outcomes indicated that design variables have significantly affected on magnification ratio of the mechanism and verified by analysis of variance and analysis of the signal to noise of grey relational *** results are also predicted by employing the tool of ANFIS in *** conclusion,the optimal findings obtained:Its magnification is larger than 40 times in comparison with the initial design,the maximum principal stress is 127.89MPa,and the first modal shape frequency obtained 397.45 ***,we found that the outcomes obtained deviation error compared with predicted results of displacement,stress,and frequency are 8.76%,3.6%,and 6.92%,respectively.

关键词： Compliant mechanism grey relational analysis taguchi method multi-objective optimization fuzzy logic system adaptive neuro-fuzzy inference system(ANFIS)

Discrete-time sliding mode control with power rate exponential reaching law of a pneumatic artificial muscle system

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Control Theory and Technology 2022年第4期20卷 514-524页

作者： Quy-Thinh Dao Trung-Kien Le Tri Van-Anh nguyen manh-Linh nguyen School of Electrical and Electronic Engineering Hanoi University of Science and TechnologyDai Co VietHanoi 11615Vietnam

This paper develops a discrete-time sliding mode controller with a power rate exponential reaching law approach to enhance the performance of a pneumatic artificial muscle system in both reaching time and chattering *** proposed method dynamically adapts to the variation of the switching function,which is based on an exponential term and a power rate term of the sliding ***,the controlled system can achieve high tracking performance while still obtain chattering-free ***,the effectiveness of the proposed method is validated through multiple experimental tests,focused on a dual pneumatic artificial muscle ***,experimental results show the effectiveness of the proposed approach in this paper.

关键词： Pneumatic artificial muscle Discrete-time sliding mode control Exponential reaching law Chattering

Object Detection in Remote Sensing Images Using Picture Fuzzy Clustering and MapReduce

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Computer Systems Science & Engineering 2022年第12期43卷 1241-1253页

作者： Tran manh Tuan Tran Thi Ngan nguyen Tu Trung Faculty of Computer Science and Engineering Thuyloi University175 Tay SonDong DaHanoi010000Vietnam

In image processing, one of the most important steps is image segmentation. The objects in remote sensing images often have to be detected in order toperform next steps in image processing. Remote sensing images usually havelarge size and various spatial resolutions. Thus, detecting objects in remote sensing images is very complicated. In this paper, we develop a model to detectobjects in remote sensing images based on the combination of picture fuzzy clustering and MapReduce method (denoted as MPFC). Firstly, picture fuzzy clustering is applied to segment the input images. Then, MapReduce is used to reducethe runtime with the guarantee of quality. To convert data for MapReduce processing, two new procedures are introduced, including Map_PFC and Reduce_*** formal representation and details of two these procedures are presented in thispaper. The experiments on satellite image and remote sensing image datasets aregiven to evaluate proposed model. Validity indices and time consuming are usedto compare proposed model to picture fuzzy clustering model. The values ofvalidity indices show that picture fuzzy clustering integrated to MapReduce getsbetter quality of segmentation than using picture fuzzy clustering only. Moreover,on two selected image datasets, the run time of MPFC model is much less thanthat of picture fuzzy clustering.

关键词： Remote sensing images picture fuzzy clustering image segmentation object detection MapReduce

On recommendation-aware content caching for 6G:An artificial intelligence and optimization empowered paradigm

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Digital Communications and Networks 2020年第3期6卷 304-311页

作者： Yaru Fu khai nguyen Doan Tony Q.S.Quek The School of Science and Technology The Open University of Hong Kong(OUHK)KowloonHong KongChina Information Systems Technology and Design Singapore University of Technology and Design487372Singapore

Recommendation-aware Content Caching(RCC)at the edge enables a significant reduction of the network latency and the backhaul load,thereby invigorating ubiquitous latency-sensitive innovative ***,the effectiveness of RCC strategies is highly dependent on explicit information as regards subscribers’content request patterns,the sophisticated caching placement policy,and the personalized recommendation *** this article,we investigate how the potentials of Artificial Intelligence(AI)and optimization techniques can be harnessed to address those core issues and facilitate the full implementation of RCC for the upcoming intelligent 6G *** this end,we first elaborate on the hierarchical RCC network ***,the devised AI and optimization empowered paradigm is introduced,whereas AI and optimization techniques are leveraged to predict the users’content preferences in real-time situations with the assistance of their historical behavior data and determine the cache pushing and recommendation decision,*** extensive case studies,we validate the effectiveness of AI-based predictors in estimating users’content preference and the superiority of optimized RCC policies over the conventional *** last,we shed light on the opportunities and challenges in the future.

关键词： Artificial intelligence Content caching Optimization techniques Recommendation 6G

Minimizing Warpage for Macro-Size Fused Deposition Modeling Parts

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Computers, Materials & Continua 2021年第9期68卷 2913-2923页

作者： Thanh Thuong Huynh Tien V.T.nguyen Quoc manh nguyen Trieu Khoa nguyen Department of Mechanical Engineering Can Tho UniversityCampus IICan ThoVietnam Faculty of Mechanical Technology Industrial University of Ho Chi Minh CityHo Chi Minh70000Vietnam Mechanical Engineering Department National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Mechanical Engineering Hung Yen University of Technology and EducationHung Yen16000Vietnam

In this study,we investigated warpage and corner lifting minimization for three-dimensional printed parts generated by macro-size fused deposition modeling(FDM).First,the reasons for warpage were theoretically *** approach revealed that the thermal deformation and differential volumetric shrinkage of the extruded molten plastic resulted in warpage of FDM *** addition,low adhesion between the deposited model and the heated or non-heated printing bed may intensify warpage *** a next step,initial small-size and medium-size models were used to identify parameters to manage and minimize warpage in a way that would reduce material consumption and running ***,a macro-size model was built to experimentally investigate and verify the technical solutions to minimize the warpage of FDM *** conclusion,an improved part with reduced warpage was efficiently produced after detailed consideration of thermal effects and adhesion *** exists to widen the application scope of FDM technology in manufacturing for processes like thermoforming that involve mold core fabrication with *** technology,which has applications not only in mechanical engineering but also in related engineering fields,is convenient and could readily be applied to practical manufacturing industries.

关键词： Fused deposition modeling corner lifting volumetric shrinkage thermal deformation acrylonitrile butadiene styrene filament

DENSITY ESTIMATES FOR SOLUTIONS OF STOCHASTIC FUNCTIONAL DIFFERENTIAL EQUATIONS

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Acta Mathematica Scientia 2019年第4期39卷 955-970页

作者： nguyen Tien DUNG Ta Cong SON Tran manh CUONG nguyen Van TAN Trinh Nhu QUYNH Department of Mathematics FPT University Hoa Lac High Tech Park Hanoi Vietnam Department of Mathematics VNU Hanoi University of Science 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Department of Foundation Academy of Cryptography Techniques Hl Chien Thang Thanh Tri Hanoi Vietnam Military Information Technology Institute 17 Hoang Sam Cau Giay Hanoi Vietnam

In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the d... 详细信息

关键词： Stochastic functional differential equations density estimates Malliavin calculus