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Effect of Ball Endc Cutterc Tilt Milling on Path Interval of Blade Surface
Jiaheng Ma,Fujian Ma,Ziguang Wang,Zhihua Sha,Shengfang Zhang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.10
Different milling posture of ball-end cutter will alter path interval and affect surface scallop-height, which was an important problem to be considered to enhance the quality and efficiency of blade surface. In view of ball end cutter tilt milling of blade surface, the relation equation between path interval and scallop-height was established by constant scallop-height method, based on the determination of collision boundary and milling sensitivity, the optimal tilt angles and path interval of blade surface milling were solved, moreover, by means of cutting simulation method, the differences between tilt milling and traditional non-tilt milling were compared and analyzed from the perspective of scallop height and processing time, and verified through comparative experiments. The results show that the optimal tilt angles of blade surface milling is 36.9°, when the path interval is fixed, the surface roughness of non-tilt milling and tilt milling are 0.719 µm and 0.561 µm respectively, the surface processing quality of tilt milling is 28.2% higher than that of non-tilt milling, when scallop-height is fixed, the total time of non-tilt milling and tilt milling are 31.21 min and 25.46 min respectively, the machining efficiency of tilt milling is 17.1% higher than that of non-tilt milling. The effectiveness of tilt milling method is verified, which can provide reference basis for high-quality and efficient machining of similar blade surfaces.
Jiaheng Duan,Song Xiao,Kunlun Zhang,Yongzhi Jing 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.2
In this paper, a novel three-dimension magnetic fl ux density analytical model of linear permanent magnet (PM) Halbach arrays with trapezoidal shape PMs, is established based on the theory of magnetic charge. The proposed analytical model is numerically effi cient and can be utilized to evaluate the eff ects on motor performance caused by varying their confi gurations. Furthermore, the confi gurations of PMs for both single and double-sided structures are optimized exploiting a surrogate model assisted by a multi-objective optimization algorithm, where the surrogated model is constructed by the kriging method with expected improvement utility function. The validity and accuracy of this proposed analytical model is verifi ed via fi nite element modeling, the optimization results with diff erent schemes of weight distribution show the further improvement of magnetic fl ux density distribution.
Cloud Data Migration Method Based on ABC Algorithm
Geng Yushui,Yuan Jiaheng,Sun Tao 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.5
Cloud storage systems has played an important role in the support of large-scale and high-performance cloud application. For the purposes of the cloud storage system, data migration is the key technology to the elastic load balancing.In this paper, we take data migration issues into the load-balancing scenarios and propose the data migration method based on the ABC algorithm. At the same time, we validated the method.In the method,we compute the load of each storage node through the comprehensive evaluation system.The system contains the following four aspects, including the available CPU,available memory, data access heat and the system response time.The cloud storage system performs the data migration operation according to the data obtained from the comprehensive evaluation system.The results show that this method can satisfy the application needs.At the same time, this method can reflect the integrated load of each node, and it also can achieve the optimal performance of the cloud storage system.
Study of Permanent Magnet Electrodynamic Suspension System with a Novel Halbach Array
Cheng Luo,Kunlun Zhang,Jiaheng Duan,Yongzhi Jing 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2
In this paper, a permanent magnet (PM) electrodynamic suspension (EDS) system with a novel Halbach array is presented, to overcome the uncontrol of the levitation force in the PM EDS system. The novel Halbach array consists by winding normal conductor coils on permanent magnets surface. The 2-D analytical expression of the space static magnetic feld is calculated using Biot-savart law and surface current method. When the vehicle-mounted novel Halbach array moves to cut the conductive plate, the space magnetic feld equations are obtained by establishing equations of magnetic vector potentials using complex Fourier transform of space static magnetic feld. The levitation force and drag force are derived using Maxwell stress tensor method. And a 2-D fnite-element model is built to validate the accuracy of this proposed analytical model. Furthermore, the efects of the main characteristic parameters on the levitation force are analysed.
Wang Peng,Wang Jiaheng 한국물리학회 2022 Current Applied Physics Vol.36 No.-
High dielectric loss materials have an important application in electromagnetic (EM) absorption fields. In this paper, the ternary nanocomposites: 1T/2H-MoS2/Mo2S3 with heterogeneous interfaces are synthesized by hydrothermal method. XRD, XPS, FTIR, SEM, and TEM measurements are applied to study the structure, morphology, and composition. The frequency spectra of complex permittivity (εr-f) are measured in 2–18 GHz by vector network analyzer. The results show that the nanocomposites have higher dielectric loss angle tangents than the reported 2H-MoS2 absorbers. Based on the εr-f spectra, the reflection loss-frequency curves (RL − f) are simulated at given thicknesses. An effective absorption bandwidth of 5.2 GHz (12.8–18 GHz) and a RL peak of − 29.49 dB are achieved in a thin thickness of 1.62 mm, which are comparable to the reported 2H-MoS2 absorbers with complex composition, showing that the 1T/2H-MoS2/Mo2S3 nanocomposites have great application potential as an EM wave absorber in the Ku band.
Chen, Zhenxing,Liu, Jiaheng,Li, Shuang,Kang, Seog Geun Hindawi Limited 2018 WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Vol.2018 No.-
<P>Two three-dimensional (3D) 16-ary signal constellations having extended lattice structures are presented in this paper. The theoretical symbol error probabilities (SEPs) of the new constellations in additive white Gaussian noise (AWGN) and Rayleigh fading channel are derived. Computer simulation confirms that the closed-form expressions for average SEPs of the constellations in the AWGN channel are very accurate. The theoretical SEP upper bounds in the Rayleigh fading channel are very tight. Since the presented constellations have larger minimum Euclidean distance (MED) than the conventional one, error performance can be improved up to 0.9 dB in an AWGN environment. Hence, the proposed constellations and their theoretical analysis can be used as a reference for the development of a wireless communication system with 3D signal constellations.</P>