检索结果-内蒙古大学图书馆

Progress in Electromagnetic Research Symposium (PIERS)

作者： Yuxin Li Wenying Zhou Jinjing Xu Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

The MIMO antenna for mobile communication terminals is proposed for improving its communication ability in different networks. It can avoid the problem of signal attenuation and poor signal quality caused by antenna band mismatch. The dimension of the overall antenna size is 58mm×120mm (0.68λ 0 ×1.41λ 0 , where λ 0 is the wavelength of 3.5GHz). The MIMO antenna can cover the following areas: GSM 1800, UMTS, LTE, and 5G band N78. The proposed antenna consists of two types of radiating units, including an E-type radiating unit and an L-type radiating unit. The E-type radiating unit contains two frequency bands of 1.71 ∼ 1.75GHz and 3.36 ∼ 3.61GHz respectively, which is worked for GSM1800 and 5G band N78. The L-type radiating unit covers 2.58 ∼ 2.69GHz, after moving the L-type patch, it can cover 2.05 ∼ 2.17GHz, which works for UMTS and 5G band LTE. The E-type patch antenna is center symmetric loaded to improve the gain of the proposed MIMO antenna. The simulation results show that the antenna’s efficiency is higher than 80% in 2.1GHz, 2.6GHz, and 3.5GHz bands with ECC (Envelope Correlation Coefficient) less than 0.16. A prototype of the proposed 6-antenna array is manufactured and measured. The measurement results show a return loss of 8.72dB and an isolation of 14.83dB, basically consistent with simulation results. It is also worth noticing that the proposed antenna could operate in the highly anticipated next-generation Wi-Fi 6E.

关键词： Correlation coefficient 5G mobile communication Simulation 3G mobile communication Mobile antennas Loss measurement Antennas

来源：评论

学校读者我要写书评

暂无评论

Vehicle Pedestrian Detection Method Based on Improved YOLOv5 Algorithm 3

Vehicle Pedestrian Detection Method Based on Improved YOLOv5...

引用

3rd International Conference on Signal Image Processing and Communication, ICSIPC 2023

作者： Chen, Zhao-Hui Ling, Xiao-Ming National Engineering Research Center for Technology of Environmental Deposition Lanzhou Jiaotong University Lanzhou730000 China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou730000 China

ISBN: (纸本)9781510670945

Vehicle pedestrian detection is a key aspect in driver assistance systems, which need to accurately detect all vehicle pedestrian targets on the roadway in order to ensure driving safety. To solve the problem of low accuracy in vehicle pedestrian target detection, this paper proposes a vehicle pedestrian detection method based on the improved YOLOv5 algorithm. In this paper, the initial anchor boxes of the dataset are re-clustered by the K-means clustering algorithm, and the CIOU loss function and DIOU_nms, are applied to the YOLOv5 algorithm to improve the target recognition effect and reduce the false and missed detection rate of small targets. The experimental results show that the mAP@0.5 of the improved YOLOv5 algorithm is improved by 1.85%. © 2023 SPIE.

关键词： Deep learning

来源：评论

学校读者我要写书评

暂无评论

Fault identification of rotating machinery based on multiscale convolution and deep residual networks 9

Fault identification of rotating machinery based on multisca...

引用

9th International Symposium on Sensors, Mechatronics, and Automation System, ISSMAS 2023

作者： Wang, Huihui Fan, Tianqi Qiu, Sen Liu, Long School of Intelligence and Electronic Engineering Dalian Neusoft University of Information Dalian116023 China Key Lab. of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education The School of Control Science and Engineering Dalian University of Technology Dalian116024 China

ISBN: (纸本)9781510672802

Rotating machinery and equipment have a wide range of industrial applications, and it is important to perform intelligent fault detection during their operation. In order to fully capture the multi-scale features of mechanical fault data while solving the degradation problem of deep networks, we propose an intelligent fault detection model combining multi-scale convolution and deep residual networks. We validate it on four publicly available datasets, and the results demonstrate the excellent performance of the proposed method. © 2024 SPIE.

关键词： Convolution Feature extraction Deep learning Machine learning Vibration Data modeling Lithium Convolutional neural networks Data centers Signal processing

来源：评论

学校读者我要写书评

暂无评论

Occupational Exposure of Therapeutic Staff in Deep Transcranial Magnetic Stimulation 35

Occupational Exposure of Therapeutic Staff in Deep Transcran...

引用

35th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2023

作者： Lu, Mai Ueno, Shoogo Lanzhou Jiaotong University Key Lab. of Opto-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou China The University of Tokyo Graduate School of Medicine Department of Biomedical Engineering Tokyo Japan

ISBN: (纸本)9789463968096

This study presented dosimetry analysis for therapeutic staff exposed to magnetic pulses from double cone and Halo-circular assembly (HCA) coils during deep transcranial magnetic stimulation (dTMS) applications. The magnetic field and the induced electric field in realistic human body model exposure to dTMS coils have been obtained by employing the impedance method. The exposure level by both double cone and HCA coils were assessed according to the limits defined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The HCA coil generates higher exposure to therapeutic staff compared to that of double cone coil. © 2023 International Union of Radio Science.

关键词： Electric fields

来源：评论

学校读者我要写书评

暂无评论

Speaker recognition based on improved ECAPA-TDNN network 5

Speaker recognition based on improved ECAPA-TDNN network

引用

2023 5th International Conference on Information Science, Electrical, and Automation Engineering, ISEAE 2023

作者： Chen, Hongyan Ling, Xiaoming Zhang, Xiaoyu Zhang, Zhen Dang, Zeifei Ji, Xiang Key Lab of Opto-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou730070 China National Engineering Research Center for Technology and Equipment of Environmental Deposition Lanzhou Jiaotong University Lanzhou730070 China

ISBN: (纸本)9781510667440

Speaker recognition, also known as voiceprint recognition, is a biometric technology with wide practicability at present. This paper summarizes and compares and analyzes the main research methods of speaker recognition at home and abroad at this stage, and proposes an improved ECAPA_TDNN algorithm. It is proved by experiments that the improved ECAPA_TDNN algorithm in this paper is superior to the classical algorithm in terms of accuracy and loss. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Speech recognition

来源：评论

学校读者我要写书评

暂无评论

State Estimation for Discrete-Time Semi-Markovian Jump Piecewise-Affine Systems with Complex Semi-Markovian Kernel 63

State Estimation for Discrete-Time Semi-Markovian Jump Piece...

引用

63rd IEEE Conference on Decision and control, CDC 2024

作者： Tang, Qi Liu, Tao Sun, Xi-Ming University of Hong Kong Department of Electrical and Electronic Engineering Hong Kong Shenzhen Institute of Research and Innovation The University of Hong Kong Hong Kong Dalian University of Technology Key Lab. of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian116024 China Dalian University of Technology School of Control Science and Engineering Dalian116024 China

ISBN: (纸本)9798350316339

This paper addresses state estimation for discretetime semi-Markovian jump piecewise-affine (PWA) systems. To handle uncertainties caused by unknown disturbances, we propose an analysis method that considers all transfer paths between different regions within the same mode. We then examine the mean-square exponential stability and L∞ performance of the error dynamic system by constructing Lyapunov functions that depend on mode, region, and sojourn time. The related criteria are derived using ellipsoidal outer approximation. Based on these criteria, we design L∞ observers. Finally, we demonstrate the applicability of our method through a numerical example. © 2024 IEEE.

关键词： Lyapunov functions

来源：评论

学校读者我要写书评

暂无评论

Remaining Useful Life Prediction for a Multi-stack Solid Oxide Fuel Cell System with Degradation Interactions

引用

CSEE Journal of Power and Energy Systems 2022年第4期8卷 1207-1214页

作者： Xiaojuan Wu Liangfei Xu Yang Huang Danan Yang Junhao Wang Houjun Wang Xi Li School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 610054China State Key Lab of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China School of Artificial Intelligencei and Automation Key Laboratory of Image Processing and Intelligent Control of Education MinistryHuazhong University of Science and TechnologyWuhan 430074China

Due to the constraints of manufacturing and materials,high-power plants cannot rely on only one solid oxide fuel cell stack.A multi-stack system is a solution for a highpower system,which consists of multiple fuel cell stacks.A short lifetime is one of the main challenges for the fuel cell before largescale commercial applications,and prognostic is an important method to improve the reliability of fuel *** from the traditional prognostic approaches applied to single-stack fuel cell systems,the key problem in multi-stack prediction is how to solve the correlation of multi-stack degradation,which can directly affect the accuracy of *** response to this difficulty,a standard Brownian motion is added to the traditional Wiener process to model the degradation of each stack,and then the probability density function of the remaining useful life(RUL)of each stack is ***,a Copula function is adopted to reflect the dependence between life distributions,so as to obtain the remaining useful life for the whole multi-stack system.1 The simulation results show that compared with the traditional prediction model,the proposed approach has a higher prediction accuracy for multi-stack fuel cell systems.

关键词： Degradation interaction multi-stack remaining useful life(RUL) solid oxide fuel cell(SOFC)

来源：评论

学校读者我要写书评

暂无评论

Design of Miniaturized Stereo Decoupled Quasi-Yagi Antenna Array by Using SRRs

Design of Miniaturized Stereo Decoupled Quasi-Yagi Antenna A...

引用

IEEE International Wireless Symposium (IWS)

作者： Jin-Jing Xu Wen-Ying Zhou Mai Lu Key Lab of Opto-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Gansu Lanzhou

This paper proposes a miniaturized stereo quasi-Yagi antenna array. When the distance between array elements is 0.16 λ 0 , the coupling is suppressed using the periodically ordered splitring resonators (SRRs). The simulation results indicate that the isolation of the decoupled antenna array at 2.4 GHz is increased by nearly four times, and the gain is almost unaffected. Meanwhile, the channel capacity of the suggested decoupled quasi-Yagi antenna array reaches 7.999 bps/Hz when the signal-to-noise ratio (SNR) is 20 dB. The effectiveness of our suggested decoupling structure is demonstrated.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Radiation Effect Analysis on Human Head Caused by Different Frequencies of Mobile Phone Antenna

Radiation Effect Analysis on Human Head Caused by Different ...

引用

International Applied Computational Electromagnetics Society Symposium (ACES)

作者： Xi-Yu Zhang Wen-Ying Zhou Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Gansu Lanzhou

This article discusses the bio-electromagnetic effects of the human head who exposure to the different operation frequency of three kinds of mobile phones. Three kinds of exposure sources with microwave and millimeter-wave bands respectively, which include the dual-band PIFA antenna operating at 900 MHz and 1860 MHz, the patch antenna operating at 3.5 GHz and the dual-band millimeter-wave antenna operating at 27 GHz and 40 GHz. We take a three-layer ball head model as the human head, and use the COMSOL Multiphysics software to simulate the specific absorption rate (SAR) and the absorbed power density (Sab) and temperature rise performance in the human head. The maximum SAR in human head is 1.41 W/kg and 4.4 W/kg, when it exposed to the microwave antenna and millimeter-wave antenna respectively. The results show that the millimeter-wave antennas have higher radiation energy than the microwave antennas for the human head model. The radiation dose absorbed in the human tissues are all below the limit restriction.

关键词： Microwave antennas Microwave integrated circuits Radiation effects Dual band Mobile handsets Specific absorption rate Software

来源：评论

学校读者我要写书评

暂无评论

Simultaneously realizing thermal and electromagnetic cloaking by multi-physical null medium

引用

opto-electronic Science 2024年第2期3卷 45-59页

作者： Yichao Liu Xiaomin Ma Kun Chao Fei Sun Zihao Chen Jinyuan Shan Hanchuan Chen Gang Zhao Shaojie Chen Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceCollege of Electronic Information and Optical EngineeringTaiyuan University of TechnologyTaiyuan 030024China

Simultaneously manipulating multiple physical fields plays an important role in the increasingly complex integrated systems,aerospace equipment,biochemical productions,*** on-chip systems with high integration level,the precise and efficient control of the propagation of electromagnetic waves and heat fluxes simultaneously is particularly *** this study,we propose a graphical designing method(i.e.,thermal-electromagnetic surface transformation)based on thermal-electromagnetic null medium to simultaneously control the propagation of electromagnetic waves and thermal fields according to the pre-designed paths.A thermal-electromagnetic cloak,which can create a cloaking effect on both electromagnetic waves and thermal fields simultaneously,is designed by thermal-electromagnetic surface transformation and verified by both numerical simulations and experimental *** thermal-electromagnetic surface transformation proposed in this study provides a new methodology for simultaneous controlling on electromagnetic and temperature fields,and may have significant applications in improving thermal-electromagnetic compatibility problem,protecting of thermal-electromagnetic sensitive components,and improving efficiency of energy usage for complex onchip systems.

关键词： transformation optics multi-physical cloak null medium

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：