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Parallel finite element computation of incompressible magnetohydrodynamics based on three iterations

Applied Mathematics and Mechanics(English Edition) 2022年第1期43卷 141-154页

作者： Qili TANG Yunqing HUANG Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationSchool of Mathematics and Computational ScienceXiangtan UniversityXiangtanHunan Province411105China

Based on local algorithms,some parallel finite element(FE)iterative methods for stationary incompressible magnetohydrodynamics(MHD)are *** approaches are on account of two-grid skill include two major phases:find the FE solution by solving the nonlinear system on a globally coarse mesh to seize the low frequency component of the solution,and then locally solve linearized residual subproblems by one of three iterations(Stokes-type,Newton,and Oseen-type)on subdomains with fine grid in parallel to approximate the high frequency *** error estimates with regard to two mesh sizes and iterative steps of the proposed algorithms are *** numerical examples are implemented to verify the algorithm.

关键词： local and parallel algorithm finite element(FE)method iteration stationary incompressible magnetohydrodynamics(MHD)

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Principled Design of Translation, Scale, and Rotation Invariant Variation Operators for Metaheuristics

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Chinese Journal of Electronics 2023年第1期32卷 111-129页

作者： TIAN Ye ZHANG Xingyi HE Cheng TAN Kay Chen JIN Yaochu Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education Institutes of Physical Science and Information Technology Anhui University School of Artificial Intelligence Anhui University School of Electrical and Electronic Engineering Huazhong University of Science and Technology Department of Computing The Hong Kong Polytechnic University Faculty of Technology Bielefeld University

A large number of metaheuristics have been proposed and shown high performance in solving complex optimization problems. While most variation operators in existing metaheuristics are empirically designed,new operators are automatically designed in this work,which are expected to be search space independent and thus exhibit robust performance on different *** work first investigates the influence of translation invariance, scale invariance, and rotation invariance on the search behavior and performance of some representative operators. This work then deduces the generic form of translation, scale, and rotation invariant operators, and proposes a principled approach for the automated design of operators, which searches for high-performance operators based on the deduced generic form. The experimental results demonstrate that the operators generated by the proposed approach outperform state-of-the-art ones on a variety of problems with complex landscapes and up to 1000decision variables.

关键词： Deep learning Metaheuristics Reinforcement learning Benchmark testing Search problems Robustness Behavioral sciences

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IDENTIFYMIX: AN EFFICIENT TWO-STAGE LEARNING APPROACH TO COMBATING LABEL NOISE

Journal of Applied and Numerical Optimization

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Journal of Applied and Numerical Optimization 2023年第2期5卷 237-253页

作者： Tong, Kai Ke, Xiao Fujian Provincial Key Laboratory of Networking Computing and Intelligent Information Processing College of Computer and Data Science Fuzhou University Fuzhou350116 China Key Laboratory of Spatial Data Mining & Information Sharing Ministry of Education Fuzhou350003 China

Deep neural networks require correct label annotation during supervised learning. It is inevitable, however, that some labels are noisy during the labeling process. A deep neural network retains incorrect labels during training, resulting in a degradation of performance. Therefore, it is essential to identify samples with potentially correct labels. In state-of-the-art methods, small-loss samples are chosen for subsequent training through a sample selection strategy. Howerver, it typically ignores the imbalance in noise ratios between mini-batches when performing sample selection within each minibatch. Further, numerous valuable samples with high losses are discarded, which adversely affects the generalization performance of the model, particularly under conditions of high noise ratios. To this end, this paper proposes IdentifyMix, an effective two-stage learning approach for noisy robust learning that combines an unique sample selection strategy and the semi-supervised learning technique. By observing how the dynamics of network training are changing, AUM (Area Under the Margin) provides a criterion that is applied in this research to identify mislabeled data. Moreover, by combining semi-supervised learning with contrastive learning and data augmentation, it is possible to extract more useful information from mislabeled samples. Experiments on several synthetic and real-world noise benchmarks demonstrate the effectiveness of IdentifyMix compared with state-of-the-art methods. © 2023 Journal of Applied and Numerical Optimization.

关键词： Image classification

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A compact, metasurface-based wideband circularly polarized patch antenna with L-shaped AR tuning stubs

A compact, metasurface-based wideband circularly polarized p...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Yongkang Yuan Minquan Li Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University Hefei China

ISBN: (数字)9798350355581

ISBN: (纸本)9798350355598

A compact, wideband circularly polarized (CP) patch antenna based on the metasurface (MS) is presented. The antenna composed of a truncated corner square patch with four L-shaped axial ratio (AR) tuning stubs is sandwiched between the metasurface (MS) and the ground plane. The MS is composed of a lattice of 4 × 4 periodic metal plates. When surface waves on the MS are stimulated within the antenna structure, it will broaden the impedance bandwidth and AR bandwidth of the antenna. The proposed antenna adopts a stacked layout with an overall size of 40mm × 40mm × 4.5mm (0.71λ 0 × 0.71λ 0 × 0.08λ 0 , at 5.3 GHz). The simulation results show a |S 11 | < -10 dB bandwidth of 4.24-6.38 GHz (40.3%) and 3 dB AR bandwidth of 4.42-5.45 GHz (20.9%). Additionally, it achieves a peak gain of 8.67 dBi.

关键词： Surface impedance Surface waves Patch antennas Simulation Metals Metasurfaces Broadband antennas Wideband Tuning Gain

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A SIR dual-band microstrip filter loaded with shaped branches

A SIR dual-band microstrip filter loaded with shaped branche...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Zhiyan Lv Xiaodi Song Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University Hefei China

ISBN: (数字)9798350355581

ISBN: (纸本)9798350355598

In this paper, a SIR-coupled dual-band bandpass filter is proposed, which has lower insertion loss, better out-of-band rejection. The bandpass characteristics of the dual-band are obtained by bending the SIR and coupling it, and loading the shaped branches. By changing the shape of the shaped branches, a transmission pole is added in the first passband, which reduces the insertion loss of the filter and improves the rejection effect of the stopband. The simulation results show that the dual-frequency bandpass filter has a center frequency of 6.26GHz, an insertion loss of 0.17dB, a return loss of less than -27.8dB, and a relative bandwidth of 15.5% for the low band, and an insertion loss of 0.67dB, a return loss of less than -15.8dB, and a relative bandwidth of 11.6% for the high band, at a center frequency of 9.26GHz.

关键词： Band-pass filters Matched filters Microstrip filters Shape Simulation Dual band Insertion loss Bandwidth Propagation losses Passband

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A C-band quad-cluster low-profile broadband circularly polarized antenna array based on sequentially rotating metasurface-based

A C-band quad-cluster low-profile broadband circularly polar...

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International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Rongxian Bai Minquan Li Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University Hefei China

ISBN: (数字)9798350355581

ISBN: (纸本)9798350355598

This paper proposes a metasurface-based left-handed circularly polarized (CP) sequential rotating metasurface-based (MTS) antenna array for C-band. The array comprises a cluster of 4 × 4 periodically aligned MTS cells, which exhibit excellent performance at a low profile of 0.08 λ 0 . The antenna array is constructed on a Rogers RO4003 dielectric board in two layers. The upper surface of the upper layer is the MTS, the floor has a gap between the upper and lower layers, and the lower surface of the lower layer is the sequential feed network. The simulation conducted in HFSS software yielded an integrated bandwidth (IBW) of 95% (3.79-8.54 GHz) and an antenna radiation bandwidth (ARBW) of 49.8% (3.77-6.26 GHz), respectively. The dimensions of the antenna are 1.33λ 0 × 1.33λ 0 × 0.08λ 0 . This configuration results in a miniaturized, compact, and low-profile antenna array. This antenna configuration is applicable to satellite communications using circularly polarized waves through MTS units.

关键词： Satellite antennas C-band Bandwidth Antenna feeds Metasurfaces Software Broadband communication Broadband antennas Satellite communications Antenna arrays

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Enhanced Discriminant Analysis Based Fault Diagnosis Scheme for Marine Diesel Engines 11

Enhanced Discriminant Analysis Based Fault Diagnosis Scheme ...

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11th IEEE Data Driven Control and Learning Systems Conference, DDCLS 2022

作者： Zhong, Kai Wang, Jiayi Pan, Donghui Institutes of Physical Science and Information Technology Anhui University Key Laboratory of Intelligent Computing and Signal Processing of the Ministry of Education Anhui Hefei230601 China School of Mathematical Science Anhui University Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education Anhui Hefei230601 China

ISBN: (数字)9781665496759

ISBN: (纸本)9781665496759

Since the marine diesel engine is one of the most popular power equipments for modern shipping, accurate and timely diagnose the faults occurred in diesel engine is extraordinary important for long service life and high reliability. Note that Fisher discriminant analysis (FDA) has been widely applied in fault diagnosis field. However, it is quite susceptible to the small sample size (SSS) problem, which is very common in the running process of diesel engine. In response to the problem, this study pro-poses a new fault classification criterion based exponential discriminant analysis (EDA) scheme for diesel engine fault diagnosis, in which the exponential transformation is carried out first to enlarge the margin between different classes, thus the different fault classes are further separated and the diagnosis capability is enhanced. In addition, the theorems of matrix exponential guarantee that the matrix exp (Sw) is always full-rank, even though the Sw is singular. That means, the novel methodology is still appli-cable when confronts with the SSS problem. Finally, based on the more reasonable fault classification criterion, the simulation results on a real-world two-stroke six-cylinder low-speed marine diesel engine indicate that the EDA based diagnosis scheme achieves higher fault diagnosis accuracy with good robustness and practicability in real-world engineering applications. © 2022 IEEE.

关键词： Failure analysis

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DOA Estimation for RIS Assisted Multi-User Wireless Communication System with Squared-Sine Error Criterion and Lawson Norm Constraint 6

DOA Estimation for RIS Assisted Multi-User Wireless Communic...

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6th IEEE International Conference on Electronic Information and Communication Technology, ICEICT 2023

作者： Yu, Canping Li, Li Li, Yingsong Sun, Dazhi Li, Liping Huang, Zhixiang Loh, Tian Hong Anhui University Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education China Beijing101399 China National Physical Laboratory Electromagnetic and Eletrochemical Technologies Department Middlesex Teddington United Kingdom

ISBN: (纸本)9798350399059

Reconfigurable intelligent surface (RIS) can control the phase of reflected signals, and has become a hotspot in the field of wireless communication. In this paper, we propose a direction-of-arrival (DOA) estimation algorithm for RIS assisted multi-user wireless communication systems with squared-sine error criterion and Lawson norm constraint. This algorithm utilizes the sparsity of the signal and can achieve fast and accurate DOA estimation under the interference of impulsive noises. To suppress the line-of-sight (LOS) interference and thus to maximize the received signal-to-interference-plus-noise ratio (SINR), we also propose a random optimal phase selection (ROPS) technique to design the control matrix of RIS elements. The simulation results show that the proposed algorithm performs better than the existing methods. © 2023 IEEE.

关键词： Impulse noise

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Dual-notch Ultra-wideband Bandpass Filter Based On Folded Dual-mode Resonator

Dual-notch Ultra-wideband Bandpass Filter Based On Folded Du...

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Li, Qingqing Wu, Xianliang Huang, Zhixiang Anhui University Hefei230601 China Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Hefei230601 China

ISBN: (纸本)9781665452366

Aiming at the problem that ultra-wideband systems are easily interfered by narrowband signals, In this paper, a novel ultra-wideband (UWB) bandpass filter with dual-notch characteristics. This filter is mainly composed of Composition of a multimode resonator (MMR)and a folded dual-mode step-impedance resonator. Paralleling T-shaped SIR stubs in the basic MMR structure realizes the introduction of transmission zeros within the passband. At the same time, a pair of high-impedance stubs are also loaded to extend the upper stopband of the filter, and a folded dual-mode stepped impedance resonator is coupled below the filter to generate dual-notch frequencies. Through the electromagnetic simulation software HFSS for simulation optimization, the simulation results show that the passband of the filter is 3.4211.21GHz and its notch frequencies are 8.8GHz and 9.5GHz respectively. Insertion loss below 0.5dB and stopband up to 20GHz (S21 © 2022 IEEE.

关键词： Electromagnetic simulation

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Point Pattern Matching Based on Spectra of Directed Graphs

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Chinese Journal of Electronics 2023年第4期20卷 662-666页

作者： LIANG Dong ZHU Ming FAN Yizheng YAN Pu Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei China

We present a novel algorithm for point pattern matching by means of spectra of directed graphs. Given a feature point-set, we construct a weighted directed graph and skew-symmetric matrix associated with the graph. By using spectral decomposition of the matrix, we give a spectral representation of the feature points with half of the eigenvectors. We theoretically analyze that our method can well deal with the matching problem under affine transformation. The expreiments applied to synthetic data and real-world images show the effectiveness of our method.

关键词： Technological innovation Directed graphs Medical services Matrix decomposition Pattern matching Synthetic data

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