Your search for: 'author:("Xu, Wei")' has returned 56 results. (0.035s) Save search

Authors: Bao, Xiaohua | Fang, Jinlong | Ni, Youyuan | Xu, Wei | Wu, Changjiang

Article Type: Research Article

Abstract: Induction machines with conventional skewed rotor have lower starting torque compared with non-skewed rotor induction motors. In order to improve the electromagnetic torque, an induction motor with two different doubly skewed rotors was proposed in this paper. The fundamental electromagnetic torque and harmonic electromagnetic torque are analyzed by the virtual displacement method. Theoretical analysis shows that both doubly skewed rotor induction motor without middle ring (DSRIMWOMR) and doubly skewed rotor induction motor with middle ring (DSRIMWMR) can efficiently reduce the harmonic torque. The reduction of harmonic torque can improve the starting torque and reduce the torque ripple. The validity of …the analytical method was verified by a large number of three dimensional (3-D) finite element simulations. Results of 3-D finite element analysis (FEA) indicated that both DSRIMWOMR and DSRIMWMR can improve starting torque compared with the conventional skewed rotor induction motor. Furthermore, the optimal skew width for improving the starting torque and reducing torque ripple was ascertained according to different 3-D finite element simulations. Show more

Keywords: Starting torque, torque ripple, doubly skewed rotor induction motor, skew width, 3-D finite element method

DOI: 10.3233/JAE-170085

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 55, no. 4, pp. 583-595, 2017

Authors: Xu, Wei | Ding, Wenfeng | Zhu, Yejun | Yang, Changyong

Article Type: Research Article

Abstract: This article mainly carries out the numerical simulation and experimental verification of heating temperature characteristics during fabrication of monolayer brazed cubic boron nitride (CBN) grinding wheels using the rotating induction brazing technique. Effects of the critical heating factors in the rotating induction brazing process, such as induction current, current frequency, heating gap and scanning speed are analyzed, respectively. It was found that, the maximum value of heating temperature increases nonlinearly with the increasing induction current and current frequency, and with decreasing of the heating gap and scanning speed. The empirical formula of heating temperature is established, and the rotating induction …heating parameters are accordingly optimized to control the brazing temperature range of 880-940°C, which has been confirmed valid during the rotating induction brazing operation of monolayer CBN grinding wheels. Show more

Keywords: Rotating induction brazing, numerical simulation;, heating temperature;, optimization;, steel wheel matrix

DOI: 10.3233/JAE-160083

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. 4, pp. 697-713, 2017

Authors: Wang, Wei | Xu, Wei-lin | Liu, Shan-jun

Article Type: Research Article

Abstract: Chengdu-Kunming Railway is an important transport line on southwestern China. However, this railway's safety is often threatened by debris flows. How to effectively forecast and alarm the debris flow disasters and reduce the losses is the aim to study the prevention system in this paper. The factors to cause or influence debris flow are divided into four parts - the basin environmental factors, the basin meteoric factors, the prevention work's elements and the flood-relief work's elements, and the prevention system is made up of three models - a judgment model to assess the debris flow gully's seriousness, a forecast model …to predict the debris flow's occurrence and an alarm model to evaluate the debris flow's disaster. Afterwards, a concise structure chart is worked out and verified by the field data from Chengdu-Kunming Railway. This prevention system will provide beneficial reference for the debris flow's monitoring network to be executed on Chengdu-Kunming Railway. Show more

Keywords: debris flow disaster, Chengdu-Kunming Railway, prevention system

Citation: Journal of Environmental Sciences, vol. 13, no. 3, pp. 333-336, 2001

Authors: Wang, Yi | Zhu, Jianguo | Wang, Shuhong | Guo, Youguang | Xu, Wei

Article Type: Research Article

Abstract: In this paper a comprehensive nonlinear model of surface mounted permanent magnet synchronous machine (SPMSM) is proposed considering both the structural and the saturation saliencies to enable the numerical simulation of new rotor position detection algorithms. An experiment platform is carried out to test and collect the incremental inductance values varying again the stator current levels and the rotor position. The Least Relative Residual Sum of Square (LRRSS) method is employed in the nonlinear inductance function regression. After experimentally identifying out all the parameters, a nonlinear mathematic model of SPMSM is built up. Furthermore, the direct torque control (DTC) scheme …is applied to this new model to verify the model and simulate the machine performance. Show more

Keywords: Finite element methods, nonlinear magnetic, PM machines, saturation saliency

DOI: 10.3233/JAE-2010-1147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 473-479, 2010

Authors: Zhao, Xingqian | Shuai, Changgeng | Xu, Wei | Chen, Demin | Hu, Zechao

Article Type: Research Article

Abstract: To isolate the vibration transmitted from the propeller to the vessel’s hull, the main engine, the shaft together with the bearings are proposed to be installed on a large-scale isolation system. Permanent magnetic thrust bearing (PMTB) is applied to further reduce the vibration transmission. The Coulombian model is adopted to calculate the force and stiffness, which determine the application feasibility of the PMTB in vessels. Explicit computations are presented for stacked PMTB. The calculation result is compared with that obtained by finite element method (FEM) and experimentally tested. It is revealed that the Coulombian model is accurate enough and more …economic than the FEM, which make it advantageous to the structure design and parameter optimization of PMTB. In the influence study by Coulombian model, it is found that the airgap width can exponentially change the maximum axial magnetic force and stiffness; the radial width is not a sensitive factor for both force and stiffness; the axial length should be 4/5 of the radial thickness to obtain the largest force and decent stiffness. Show more

Keywords: Permanent magnetic thrust bearing, Coulombian model, finite element method, parameter optimization, magnetic force and stiffness

DOI: 10.3233/JAE-209007

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 1, pp. 171-186, 2020

Authors: Yang, Enhui | Mo, Jinqiu | Liu, Handan | Xu, Wei | Wang, Shigang

Article Type: Research Article

Abstract: The disposal of interface conditions is a key problem for the application of meshless method in numerical computation of engineering electromagnetic field. Due to the meshless methods employing moving least square approximation scheme can not verify the Kronecker-δ property, the interface conditions can not be enforced automatically as done in FEM. This paper applies methods based on the modification of the weak form, such as Lagrange multiplier method and penalty method, to impose electromagnetic field interface conditions. Using above methods, the general models of electromagnetic field interface conditions expressed by A-φ-A approach are implemented by using the element-free Galerkin method. …Then, a rectangular cross section solenoid with analytical solution is employed to validate the effect of the imposition of electromagnetic field interface conditions, and discuss the potential problems when using above two methods in different cases. Show more

Keywords: Electromagnetic field, interface conditions, element-free Galerkin method, Lagrange multiplier method, penalty method

DOI: 10.3233/JAE-2009-1051

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 127-145, 2009

Authors: Li, Congdong | Yu, Yinyun | Xu, Wei | Sun, Jianzhu

Article Type: Research Article

Abstract: In order to better meet customer needs and respond to market demands more quickly, mounting number of manufacturing companies have begun to bid farewell to the traditional unitary manufacturing model. The collaborative manufacturing model has become a widely adopted manufacturing model for manufacturing companies. Aiming at the problem of partner selection for collaborative manufacturing of complex products in a collaborative supply chain environment, this paper proposes a multi-objective decision-making model that comprehensively considers the maximization of the matching degree of manufacturing capacity and the profits of supply chain, and gives the modeling process and application steps in detail. The method …first uses fuzzy theory to evaluate the manufacturing capabilities of candidate collaborative manufacturing partners. Secondly, Vector Space Model (VSM) is used to calculate the matching degree of manufacturing capacity and manufacturing demand. Then, the paper studied the profit of the supply chain under the “non-cooperative” mechanism and the “revenue sharing” mechanism. Furthermore, the decision-making model is established. Finally, a simulation was carried out by taking complex product manufacturing of Gree enterprise as an example. The research results show the feasibility and effectiveness of the method. Show more

Keywords: Collaborative manufacturing, supply chain collaboration, collaborative partner selection

DOI: 10.3233/JIFS-219000

Citation: Journal of Intelligent & Fuzzy Systems, vol. 41, no. 4, pp. 5153-5165, 2021

Authors: Xu, Wei | Mao, Jun-Jun | Zhu, Meng-Meng

Article Type: Research Article

Abstract:  The group decision-making problem usually involves decision makers (DMs) from different professional backgrounds, which leads to a considerable point, that it is the fact that there will be a certain difference in the professional cognition, risk preference and other hidden inherent factors of these DMs to the objective things that need to be evaluated. To improve the reasonability of decision-making, these hidden inherent preference (HIP) of DMs should be determined and eliminated prior to decision making. As a special form of fuzzy set, q-rung orthopair fuzzy numbers (q-ROFNs) is a useful tool to process uncertain information in decision making problems. …Hence, under the environment of q-ROFNs, the determination of HIP based on distance from average score is proposed and a risk model is established to eliminate the HIP by analyzing the possible impact. Meanwhile, a dominant function is proposed, which extends the comparison method between q-ROFNs and an integrated decision-making method is provided. Finally, considering the application background of double carbon economy, an example by selecting the best design of electric vehicles charging station (EVCS) is conducted to illustrate the proposed method, and the feasibility and efficiency are verified. Show more

Keywords: group decision-making, q-ROFNs, hidden inherent preference, risk model, double carbon economy

DOI: 10.3233/JIFS-221702

Citation: Journal of Intelligent & Fuzzy Systems, vol. 44, no. 1, pp. 1369-1384, 2023

Authors: Jing, Leng | Bo, Zhu | Tian, Qingxiang | Xu, Wei | Shi, Jiaoxue

Article Type: Research Article

Abstract: The current online education platform has gradually replaced the traditional teaching mode and has become an efficient teaching method. Flipping classroom is a new teaching mode under the background of the rapid development of information technology. It is also an important way of multimedia network teaching. However, compared with the traditional teaching mode, teachers in the online teaching platform cannot judge the students’ psychological activities through the students’ state of mind, and they can grasp the students’ learning status through the teaching process. Based on this, based on the cloud computing platform, this study improves the data transmission effect and …improves the algorithm according to the learning process of the online education platform. Moreover, this study combines support vector machine to construct a student state recognition system suitable for online education platform and conducts algorithm performance analysis through experiments. In addition, this study uses MKmeans algorithm, Kmeans algorithm and improved Kmeans algorithm, that is, K-mediods and Xmeans algorithm to compare the pre-processed final data sets. The research results show that the proposed algorithm is suitable for network teaching platform and has certain practical effects. Show more

Keywords: Cloud computing, improved SVM algorithm, support vector, Network teaching, flipping classroom

DOI: 10.3233/JIFS-179952

Citation: Journal of Intelligent & Fuzzy Systems, vol. 39, no. 2, pp. 1793-1803, 2020

Authors: Xu, Wei | Qian, Lei | Yuan, Xiaoyan | Lu, Yong

Article Type: Research Article

Abstract: BACKGROUND: MicroRNAs (miRNAs) have emerged as crucial players in the initiation and development of atherosclerosis (AS), and the low miR-223-3p level is observed in AS patients. However, the function and mechanism behind miR-223-3p in AS progression have not been fully elucidated. METHOD: In the present study, THP-1 cells treated with oxidized low-density lipoprotein (ox-LDL) were employed as the cell model of AS. The expression levels of miR-223-3p, NLR family pyrin domain containing 3 (NLRP3), caspase-1, pro-caspase-1, cleaved interleukin 18 (IL-18), cleaved IL-1β, and forkhead box O3 (FOXO3) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot (WB) …analyses. The relationship between miR-223-3p and FOXO3 or NLRP3 was determined using a dual-luciferase reporter assay. The production of IL-1β, IL-18, IL-6, and TNF-α was examined by Enzyme-linked immunosorbent assay (ELISA). RESULTS: MiR-223-3p was decreased in AS patients and ox-LDL-induced THP-1 cells, and its upregulation downregulated the abundance of NLRP3, caspase-1, cleaved IL-18, cleaved IL-1β, IL-1β, IL-6, and TNF-α in THP-1 cells treated with ox-LDL or not, and the depletion of miR-223-3p revealed an opposite phenomenon. NLPR3 and FOXO3 were identified as two authentic targets of miR-223-3p. Knockdown of NLRP3 or FOXO3 reversed the stimulatory effect of the miR-223-3p inhibitor on the inflammatory responses of THP-1 cells. CONCLUSIONS: Our data indicate that miR-223-3p inhibited ox-LDL-mediated NLRP3 inflammasome activation via directly targeting NLRP3 and FOXO3 in THP-1 cells, which offered a prospective therapeutic target for AS therapy. Show more

Keywords: Atherosclerosis, microRNA-223-3p, inflammasome, FOXO3, NLRP3

DOI: 10.3233/CH-211232

Citation: Clinical Hemorheology and Microcirculation, vol. 81, no. 3, pp. 241-253, 2022