检索结果-内蒙古大学图书馆

Dual-Band Reflectarray Antennas Using Integrated Resonant and Non-Resonant Natures of Metallic Waveguide Elements at Millimeter Wave Frequencies

引用

Radio Science 2023年第1期58卷 1-13页

作者： Chou, H.-T. Wang, N.-N. Fang, M. Wang, L.-Q. Akkaraekthalin, P. Torrungrueng, D. Graduate Institute of Communication Engineering National Taiwan University Taipei Taiwan School of Electronics and Information Engineering Harbin Institute of Technology Harbin China Department of Electrical and Computer Engineering Faculty of Engineering King Mongkut's University of Technology North Bangkok Bangkok Thailand Research Center of Innovation Digital and Electromagnetic Technology Department of Teacher Training in Electrical Engineering Faculty of Technical Education King Mongkut's University of Technology North Bangkok Bangkok Thailand

Pure metallic reflectarray antennas have good power efficiency and low fabrication cost, limited to single-band operation in the past. A dual-band reflectarray antenna is developed for two directional beams by two feeds. The reflecting elements are metal waveguides and have novel properties of both resonant and non-resonant modes at the two frequency bands. The low and high-frequency bands can be easily separated by the cutoff frequency of waveguide modes. The phase-changing mechanisms via ray optics and fundamental waveguide modes, respectively, provide simple formulations for the elemental structure design of directional beams. Radiation characteristics of the linear and circular polarizations are cross-examined with a good performance by full-wave simulations using HFSS, FEKO, and CST at 28 and 60 GHz bands for 5G front-haul network applications. In particular, we have used HFSS to simulate the reflecting elements' basic characteristics of phase variation, FEKO to simulate the linear polarization antenna case, and CST to simulate the circular polarization antenna case, respectively. © 2023. American Geophysical Union. All Rights Reserved.

关键词： Cutoff frequency

来源：评论

学校读者我要写书评

暂无评论

Reversible Data Hiding in Shared Images with Separate Cover Image Reconstruction and Secret Extraction

引用

IEEE Transactions on Cloud Computing 2024年第1期12卷 186-199页

作者： Xiong, Lizhi Han, Xiao Yang, Ching-Nung Shi, Yun-Qing Nanjing University of Information Science and Technology School of Computer Science Nanjing210044 China Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology Engineering Research Center of Digital Forensics Ministry of Education Nanjing210044 China Shanghai Jiao Tong University School of Electronic Information and Electrical Engineering Shanghai200240 China National Dong Hwa University Department of Computer Science & Information Engineering Hualien974301 Taiwan New Jersey Institute of Technology ECE Department NewarkNJ07102 United States

Reversible data hiding is widely utilized for secure communication and copyright protection. Recently, to improve embedding capacity and visual quality of stego-images, some Partial Reversible Data Hiding (PRDH) schemes are proposed. But these schemes are over the plaintext domain. To protect the privacy of the cover image, Reversible Data Hiding in Encrypted Images (RDHEI) techniques are preferred. In addition, the full separability of cover image reconstruction and data restoration is also an important characteristic that cannot be achieved by most RDHEI schemes. To solve the issues, a partial and a complete Reversible Data Hiding in Shared Images with Separate Cover Image Reconstruction and Secret Extraction (RDHSI-SRE) are proposed in this paper. In the proposed schemes, the secret data is divided by Secret Sharing (SS). Then, the marked shared images are generated based on the proposed modify-and-recalculate strategy. The receiver can extract embedded data and reconstruct the image separably using k-out-of-n marked shared images. In the embedding phase of partial RDHSI-SRE (PRDHSI-SRE), the pixel values are modified according to the proposed Minimizing-Square-Errors Strategy to achieve high visual quality, and the complete RDHSI-SRE (CRDHSI-SRE) embeds data by modifying random coefficients to achieve reversibility. The experimental results and theoretical analyses demonstrate that the proposed schemes have a high embedding performance. Most importantly, the proposed schemes are fault-tolerant and completely separable. © 2013 IEEE.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

WAVEFIELD CHARACTERIZATION OF LAMB WAVE PROPAGATION IN COMPOSITE PLATES BASED ON GUIDED WAVE OMNIDIRECTIONAL WAVENUMBER SIMULATION 18

WAVEFIELD CHARACTERIZATION OF LAMB WAVE PROPAGATION IN COMPO...

引用

18th Symposium on Piezoelectricity, Acoustic Waves, and Device Applications, SPAWDA 2024

作者： Wang, Lei Liu, Hongye Sun, Maoxun Chen, Xiaorong Shen, Liang Qiu, Chongpeng Tian, Zhenhua School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China Department of Mechanical Engineering Virginia Polytechnic Institute State University 1145 Perry Street BlacksburgVA24061 United States

ISBN: (纸本)9798331523732

With the growing application of composite materials in sectors such as aerospace, automotive, and wind energy, accurately assessing their mechanical properties is critical for effective non-destructive testing (NDT) and structural health monitoring (SHM). In this paper, a three-dimensional finite element model was developed to generate the fundamental A0 Lamb wave mode within an 8-layer orthotropic laminate, addressing the complexities associated with the anisotropic behavior of composites. Utilizing the Legendre Orthogonal Polynomial Expansion (LOPE) method, we characterized the wave number profile, revealing significant directional dependence in wave propagation across multilayer laminates. The results demonstrated strong agreement between the analytical predictions from the LOPE method and the finite element simulations, confirming the robustness of our modeling approach. Additionally, we introduced an innovative omnidirectional wavefield representation method, effectively mitigating the influence of phase and group velocity steering angles. These findings enhance our understanding of guided wave dynamics in composite materials, offering valuable insights for the development of more effective detection strategies and assessments of structural integrity in complex composite systems. © 2024 IEEE.

关键词： Gravity waves

来源：评论

学校读者我要写书评

暂无评论

ELASTIC CONSTANTS INVERSION OF ZIRCONIUM TUBE BASED ON THE LONGITUDINAL MODE OF GUIDED WAVE 18

ELASTIC CONSTANTS INVERSION OF ZIRCONIUM TUBE BASED ON THE L...

引用

18th Symposium on Piezoelectricity, Acoustic Waves, and Device Applications, SPAWDA 2024

作者： Ji, Haoshuai Liu, Hongye Sun, Maoxun Chen, Xiaorong Shen, Liang Qiu, Chongpeng Tian, Zhenhua School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China Department of Mechanical Engineering Virginia Polytechnic Institute State University 1145 Perry Street BlacksburgVA24061 United States

ISBN: (纸本)9798331523732

Estimating elastic constants in materials is markedly important in engineering and technology. Ultrasonic guided wave non-destructive testing provides an effective means for accurately assessing material properties. This paper presents a method for inverting the elastic constants of hollow pipes using the longitudinal mode of ultrasonic guided waves combined with a genetic algorithm (GA). The Legendre orthogonal polynomial expansion (LOPE) method serves as the forward model for analyzing the dispersion curves of axisymmetric guided wave modes, while the GA performs the inversion. A carefully designed finite element (FE) model generates pseudo-experimental data, which is transformed into the frequency-wave number domain for input into the GA. The comparison between simulation results and theoretical analysis confirms the validity of the FE model and the accuracy of the detected modes. The results demonstrate that the proposed method effectively inverts the elastic constants of isotropic hollow cylindrical structures, with an inversion error of less than 2% based on pseudo-experimental data. © 2024 IEEE.

关键词： Nondestructive examination

来源：评论

学校读者我要写书评

暂无评论

Belief Combination of Classifiers for Incomplete Data

引用

IEEE/CAA Journal of Automatica Sinica 2022年第4期9卷 652-667页

作者： Zuowei Zhang Songtao Ye Yiru Zhang Weiping Ding Hao Wang IEEE the Research Center for Optical Fiber Sensing Zhejiang Laboratory the School of Automation Northwestern Polytechnical University the School of Cyber Engineering Xidian University the Department of Computer Science CY Cergy Paris Université the School of Information Science and Technology Nantong University the School with of Cyber Engineering Xidian University the Department of Computer Science Norwegian University of Science and Technology

Data with missing values,or incomplete information,brings some challenges to the development of classification,as the incompleteness may significantly affect the performance of *** this paper,we handle missing values in both training and test sets with uncertainty and imprecision reasoning by proposing a new belief combination of classifier(BCC)method based on the evidence *** proposed BCC method aims to improve the classification performance of incomplete data by characterizing the uncertainty and imprecision brought by *** BCC,different attributes are regarded as independent sources,and the collection of each attribute is considered as a ***,multiple classifiers are trained with each subset independently and allow each observed attribute to provide a sub-classification result for the query ***,these sub-classification results with different weights(discounting factors)are used to provide supplementary information to jointly determine the final classes of query *** weights consist of two aspects:global and *** global weight calculated by an optimization function is employed to represent the reliability of each classifier,and the local weight obtained by mining attribute distribution characteristics is used to quantify the importance of observed attributes to the pattern *** comparative experiments including seven methods on twelve datasets are executed,demonstrating the out-performance of BCC over all baseline methods in terms of accuracy,precision,recall,F1 measure,with pertinent computational costs.

关键词： Classifier fusion classification evidence theory incomplete data missing values

来源：评论

学校读者我要写书评

暂无评论

5G Antenna Gain Enhancement Using a Novel Metasurface

引用

computers, Materials & Continua 2022年第8期72卷 3601-3611页

作者： Mubashir Ashfaq Shahid Bashir Syed Imran Hussain Shah Nisar Ahmad Abbasi Hatem Rmili Muhammad Abbas Khan Department of Electrical Engineering UETPeshawar25000Pakistan Department of Electrical Engineering Chungnam National UniversityDaejeonKorea Department of Electrical Engineering University of Hafr Al BatinKSA Electrical and Computer Engineering Department Faculty of EngineeringKing Abdulaziz UniversityJeddahKSA K.A.CARE Energy Research and Innovation Center King Abdulaziz UniversityJeddah21589KSA Department of Electrical Engineering Balochistan University of Information TechnologyEngineering and Management SciencesQuettaPakistan

This article presents a Sub-6 GHz microstrip patch antenna(MPA)with enhanced gain using metamaterial(MTM)*** source MPA operates at 4.8 GHz and has a peak gain of 5.3 dBi at the resonance frequency.A window-shaped unit cell is designed and investigated through the material wave propagation *** unit cell shows an EpsilonNear Zero(ENZ)-Mu Very Large(MVL)behavior around 4.8 *** unit cell has a fourfold geometry which makes it a polarization independent metamaterial.A double layer antenna is designed by placing a 4×4 MTM slab as a superstrate above the MPA at a height of 0.208λ0;whereλ0 is the free-space wavelength at the resonance frequency of the *** matching and gain of the source antenna is improved using the *** simulation as well as measurement results show that novel antenna system has a peak gain of 7.68 dBi at 4.8 GHz and an impedance bandwidth of 0.22 *** overall dimension of the antenna is 75×60×15 mm^(3).The proposed antenna operates in the Sub-6 GHz band and is suitable for 5G applications.

关键词： Metasurface 5G gain directivity polarization

来源：评论

学校读者我要写书评

暂无评论

Temporally consistent video colorization with deep feature propagation and self-regularization learning

引用

Computational Visual Media 2024年第2期10卷 375-395页

作者： Yihao Liu Hengyuan Zhao Kelvin CKChan Xintao Wang Chen Change Loy Yu Qiao Chao Dong Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Department of Electrical&Computer Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798 Applied Research Center Tencent PCGShenzhenChina

Video colorization is a challenging and highly ill-posed *** recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and existing methods always suffer from severe flickering artifacts(temporal inconsistency)or unsatisfactory *** address this problem from a new perspective,by jointly considering colorization and temporal consistency in a unified ***,we propose a novel temporally consistent video colorization(TCVC)*** effectively propagates frame-level deep features in a bidirectional way to enhance the temporal consistency of ***,TCVC introduces a self-regularization learning(SRL)scheme to minimize the differences in predictions obtained using different time *** does not require any ground-truth color videos for training and can further improve temporal *** demonstrate that our method can not only provide visually pleasing colorized video,but also with clearly better temporal consistency than state-of-the-art methods.A video demo is provided at https://***/watch?v=c7dczMs-olE,while code is available at https://***/lyh-18/TCVC-Tem porally-Consistent-Video-Colorization.

关键词： video colorization temporal consistency feature propagation self-regularization

来源：评论

学校读者我要写书评

暂无评论

Nonlinear dynamic response of bimorph piezoelectric energy harvester with functionally graded porous core

引用

Noise and Vibration Worldwide 2023年第2-3期54卷 145-157页

作者： Akbar, Narges Soltani, Madjid Department of Mechanical Engineering Alzahra University Tehran Iran Department of Mechanical Engineering K. N. Toosi University of Technology Tehran Iran Department of Electrical and Computer Engineering University of Waterloo WaterlooON Canada University of Waterloo WaterlooON Canada Advanced Bioengineering Initiative Center Computational Medicine Center K. N. Toosi University of Technology Tehran Iran

This study deals with piezoelectric energy harvesters carrying the magnet at the free end while a magnifier connected them to the base. The harvester consists of a cantilever beam with Functionally Graded (FG) porous foam core and two piezoelectric faces while taking into account the von-Karman strains and the magnetic interaction of two magnets. The governing equation has been developed using Hamilton’s principle and reduced-order via the Galerkin method. Frequency response of vibrations and voltage derived using harmonic balance method and the adjusted model has been confirmed by parametric studies of the lumped parameter model. A parametric study is also performed to expose the effects of porosity coefficient and pattern, magnifier ratios, and excitation level on the responses. Results show that by correct selection of the magnifier parameters, the proposed harvester can provide a higher output over a wider frequency band. Also, the core porosity increases the flexibility of the beam and raised the voltage by a factor of 1.8. © The Author(s) 2023.

关键词： Porosity

来源：评论

学校读者我要写书评

暂无评论

Subject-independent emotion recognition of EEG signals using graph attention-based spatial-temporal pattern learning 41

Subject-independent emotion recognition of EEG signals using...

引用

第41届中国控制会议

作者： Yiwen Zhu Yeshuang Guo Wenzhe Zhu Lare Di Zhong Yin School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Engineering Research Center of Optical Instrument and System Ministry of EducationShanghai Key Lab of Modern Optical SystemUniversity of Shanghai for Science and Technology

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

Electroencephalography(EEG) reveals human brain activities and becomes an essential solution for exploring human intrinsic emotional *** this study,we proposed a graph attention-based spatial-temporal pattern learning method called TAGAT to take full advantage of spatial structure of EEG channels and take the nonstationary of emotions into *** attention mechanism is applied to compute weight coefficients of different spatial and temporal *** alleviate differences between subjects,a domain discriminator is added to the model based on domain adaptation to tackle subject-independent EEG emotion recognition *** on the DEAP database,our method achieves the accuracy of 56.56% and 58.91% of arousal and valence dimensions for subject-independent emotion *** effectiveness of T-AGAT method has been demonstrated when compared to other existing common methods.

关键词： Emotion recognition electroencephalography deep learning transfer learning pattern learning

来源：评论

学校读者我要写书评

暂无评论

Design of a large-range rotary microgripper with freeform geometries using a genetic algorithm

引用

Microsystems & Nanoengineering 2022年第1期8卷 59-72页

作者： Chen Wang Yuan Wang Weidong Fang Xiaoxiao Song Aojie Quan Michiel Gidts Hemin Zhang Huafeng Liu Jian Bai Sina Sadeghpour Michael Kraft College of Optical Science and Engineering Zhejiang UniversityHangzhouChina Department of Electrical Engineering and Computer Science University of LiegeLiegeBelgium ESAT-MNS University of LeuvenLeuvenBelgium PGMF and School of Physics Huazhong University of Science and TechnologyWuhanChina

This paper describes a novel electrostatically actuated microgripper with freeform geometries designed by a genetic *** new semiautomated design methodology is capable of designing near-optimal MEMS devices that are robust to fabrication *** use of freeform geometries designed by a genetic algorithm significantly improves the performance of the *** experiment shows that the designed microgripper has a large displacement(91.5μm)with a low actuation voltage(47.5 V),which agrees well with the *** microgripper has a large actuation displacement and can handle micro-objects with a size from 10 to 100μm.A grasping experiment on human hair with a diameter of 77μm was performed to prove the functionality of the *** result confirmed the superior performance of the new design methodology enabling freeform *** design method can also be extended to the design of many other MEMS devices.

关键词： handle algorithm. algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：