检索结果-内蒙古大学图书馆

Effect of radical scavenger on electrical tree in cross-linked polyethylene with large harmonic superimposed DC voltage

引用

High Voltage 2023年第4期8卷 739-748页

作者： Lewei Zhu Zhonglei Li Kai Hou Maritime College Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry SystemsTianjin University of TechnologyTianjinChina Key Laboratory of Smart Grid of Ministry of Education School of Electrical and Information EngineeringTianjin UniversityTianjinChina

In this study,three kinds of radical scavenger Chimassorb 944,Tinuvin 622,and Tinuvin 770 are used to suppress the growth of electrical trees in cross-linked polyethylene(XLPE)with transient superimposed voltage under the temperature *** tree morphology,tree length,accumulated damage,and time to breakdown are used to investigate the effect of radical scavenger on the electrical treeing *** is found that under the temperature gradient caused by the temperature rise on the high voltage side,only Tinuvin 622 can always suppress the electrical tree as the temperature gradient *** the temperature gradient caused by the temperature rise on the ground side,the three radical scavengers can all suppress the electrical *** breakdown of electrical tree exhibits the strong DC polarity ***,energy levels of these three radical scavengers are calculated through quantum chemistry,and the results indicate that radical scavengers have greater electron affinity,smaller ionisation energy,and smaller energy gap than *** to the surface potential decay test results at 60℃,it is found that all three radical scavengers can introduce deep *** different performances of radical scavengers under different temperature gradients and voltages are determined by the trap distribution characteristics,the molecular structure and chemical reaction of the additives *** is concluded that Tinuvin 622 has potential for use in high voltage direct current XLPE cable application.

关键词： radical electrical harmonic

来源：评论

学校读者我要写书评

暂无评论

A Method for Allocating Hybrid Teaching Credit Hours Using Hierarchical Analysis 25

A Method for Allocating Hybrid Teaching Credit Hours Using H...

引用

25th IEEE China Conference on System Simulation Technology and its application, CCSSTA 2024

作者： Meng, Xiangang Li, Xiaojing Xu, Liang School of Electrical Engineering and Automation Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin China

ISBN: (纸本)9798350366600

Hybrid teaching combines traditional teaching and flipped classroom, which is a new teaching mode with the advantages of both modes. In hybrid teaching mode, reasonable allocation of credit hours between traditional teaching and flipped classroom is an important issue for the teaching work. This paper first proposes a method of using hierarchical analysis to allocate credit hours for hybrid teaching of Digital Electronic Technology courses. Firstly, we divided hybrid teaching into stage and content layers, and determined the various elements of stage and content layers. Secondly, the requirements of the Analytic Hierarchy Process were applied to organize these two levels, and pairwise importance comparisons were made for each element within the level. Index judgment matrices were established for the stage level and content level, respectively. Then, the calculation steps of the Analytic Hierarchy Process were designed, and matrix operations were used to obtain the normalized weights of each element in the stage and content layers of traditional teaching and flipped classrooms. This weight was used to determine the class hours to be allocated for each stage and content. Finally, the feasibility and effectiveness of the method proposed in this paper were verified using the example of hybrid teaching hour allocation in Chapter 4 of the Digital Electronic Technology course at tianjin University of Technology. © 2024 IEEE.

关键词： Hierarchical systems

来源：评论

学校读者我要写书评

暂无评论

Sensorless control of submersible permanent magnet synchronous motor under long-line cable model 4

Sensorless control of submersible permanent magnet synchrono...

引用

2023 4th International Conference on Electrical Technology and Automatic control, ICETAC 2023

作者： Yue, Youjun Zheng, Lihua College of Electrical Engineering and Automation Tianjin Key Laboratory of Control Theory and Application for Complex Systems Tianjin University of Technology Tianjin300384 China

In the process of oil production, the submerged oil motor works 1-3 km downhole and is connected to the inverter by a long-wire cable, which generates overvoltage at the motor end due to the problem of matching the impedance of the motor with the impedance of the power cable. The downhole environment is not suitable for the installation of precision devices, such as position sensors. To solve these problems, a sensorless control method of submerged oil motors based on a high-frequency voltage injection method is proposed. A motor terminal voltage and current observer under a long-wire cable model is designed to estimate the actual values of motor terminal voltage and current by collecting the voltage and current at the inverter terminal. A three-level inverter is used to provide energy to the submersible oil electric pump through the long-wire cable, which can effectively suppress the motor terminal overvoltage compared to the two-level inverter. The control algorithm is verified by modeling the whole system using simulation software. © Published under licence by IOP Publishing Ltd.

关键词： Cables

来源：评论

学校读者我要写书评

暂无评论

Named Entity Recognition in Chinese Medical Texts Based on RoBERTa-WWM-IDCNN-CRF 25

Named Entity Recognition in Chinese Medical Texts Based on R...

引用

25th IEEE China Conference on System Simulation Technology and its application, CCSSTA 2024

作者： Tang, Lan Kong, Jie Xu, Liang Xi'an Shiyou University School of Computer Xi'an China Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems School of Electrical Engineering and Automation Tianjin China

ISBN: (纸本)9798350366600

Electronic medical records and doctor-patient conversations contain a wealth of useful information, such as disease symptoms, drug names, and cure cycles. Traditional deep learning approaches utilize bidirectional recurrent neural networks to encode text, which cannot effectively capture long-distance dependencies in text. In order to identify medical entity types in various texts more accurately, a named entity recognition approach based on RoBERTa-WWM-IDCNN-CRF is proposed. This approach introduces the RoBERTa-WWM pre-trained model, in order to improve the overall understanding of long Chinese texts for the first time. The model generates semantic representations containing prior knowledge. Then, the generated semantic representations are feed to the IDCNN to extract sentence level characteristics. Finally, the global optimal solution is obtained and the results of the named entity are produced through the CRF. The experiment indicates that the improvement of F1 score, accuracy, and recall of RoBERTa-WWM-IDCNN-CRF model are 7.94%, 4.52% and 10.02% comparing with the classical BiLSTM-CRF model. © 2024 IEEE.

关键词： Convolutional neural networks

来源：评论

学校读者我要写书评

暂无评论

Research on Sign Language Gesture Division and Gesture Extraction in Complex Background

Research on Sign Language Gesture Division and Gesture Extra...

引用

2022 International Conference on Computer Vision, application, and Algorithm, CVAA 2022

作者： Tian, Yifan Han, Fangfang Zhu, Minfeng Xu, Xiaoliang Li, Yadong School of Electrical Engineering and Automation China Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Control Theory and Applications in Complicated Systems China

ISBN: (纸本)9781510664036

Sign language plays an important role in information transmission and emotional communication between deaf-mute people and the outside world. With the development of artificial intelligence technology, the recognition, translation and generation of sign language based on digital image processing have attracted worldwide attention. In the field of sign language recognition, effective hand division and gesture extraction are the first and key steps, which directly affect the accuracy of sign language recognition. In this paper, a hand information extraction method based on depth image processing is proposed to solve the problem of sign language gesture extraction in complex background. For sign language speakers,hands are at the front of their bodies, so the depth images of sign language speakers can be collected by depth camera, and the complex background can be removed and hand information can be extracted by segmenting different color objects in the depth images. In this paper, the D435i camera of Inter is used to capture the depth image of the sign language speaker, and the HSV color space model based on the digital image is used for threshold processing of the fusion of hue components and brightness components to achieve the division of the hand position;through median filtering and mathematical morphology of digital image, division noise is removed and interference is reduced. Through skeleton extraction algorithm, the gesture gesture can be obtained. Experiments show that the proposed acquisition scheme and algorithm flow in this paper can effectively realize hand position division and gesture extraction in complex background conditions, and provide a good foundation for subsequent gesture recognition and expression. © 2023 SPIE.

关键词： Morphology

来源：评论

学校读者我要写书评

暂无评论

Simulation of Triboelectric Nanogenerator Output Characteristics of Different Resistance Loads 25

Simulation of Triboelectric Nanogenerator Output Characteris...

引用

25th IEEE China Conference on System Simulation Technology and its application, CCSSTA 2024

作者： Xu, Liang Zhang, Xiuzhe Du, Xiuke Yue, Xiaolong Zhao, Xiande Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin China Beijing Academy of Agriculture and Forestry Sciences Key Laboratory of Agricultural Sensors Ministry of Agriculture Rural Affairs Research Center of Intelligent Equipment Beijing China

ISBN: (纸本)9798350366600

With the increasing demand for green energy, triboelectric nanogenerators (TENG) have the potential to harvest energy from the environment in a small size range to power microelectronic devices. Still, its performance is affected by impedance matching problems. In this study, the effect of impedance matching on the performance of the TENG was investigated. The generator output power is simulated by Simulink software, and the theoretical usability of TENG was demonstrated by driving the load. Firstly, a mathematical model of the TENG was developed to consider its operating principle, and the transferred charge and voltage-current output under different impedance conditions were simulated. Then, the effect of impedance matching on the output of the TENG on its generator was analyzed by adjusting the impedance of the TENG with the external circuit. The results show that by adjusting the impedance value, the generator can be made to work in a more efficient operating region, which helps to promote the development of TENG technology. © 2024 IEEE.

关键词： Triboelectricity

来源：评论

学校读者我要写书评

暂无评论

Composite-mask GAN based on refined optical flow and disparity map for SLAM visual odometry

引用

Optoelectronics Letters 2025年

作者： JI Yuehui JIANG Jingwei LIU Junjie SONG Yu GAO Qiang School of Electrical Engineering and Automation， Tianjin University of Technology Tianjin Key Laboratory of Control Theory and Application for Complex Systems

Although deep learning methods have been widely applied in slam visual odometry over the past decade with impressive improvements， the accuracy remains limited in complex dynamic environments. In this paper， a composite mask-based generative adversarial network is introduced to predict camera motion and binocular depth maps. Specifically， a perceptual generator is constructed to obtain the corresponding parallax map and optical flow from between two neighboring frames. Then， an iterative pose improvement strategy is proposed to improve the accuracy of pose estimation. Finally， a composite mask is embedded in the discriminator to sense structural deformation in the synthesized virtual image， thereby increasing the overall structural constraints of the network model， improving the accuracy of camera pose estimation， and reducing drift issues in the Visual Odometer. Detailed quantitative and qualitative evaluations on the KITTI dataset show that the proposed framework outperforms existing conventional， supervised learning and unsupervised depth VO methods， providing better results in both pose estimation and depth estimation.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Study on the Falling Off Position and Heat Shift of Bonding Wire Based on Temperature Distribution Coefficient 17th

Study on the Falling Off Position and Heat Shift of Bonding ...

引用

17th Annual Conference of China Electrotechnical Society, CES 2022

作者： Dong, Chao Hu, Jingwei Du, Mingxing Yin, Jinliang Wei, Yifan Liu, Xueting Tianjin Key Laboratory of Control Theory and Application of Complex Systems Tianjin University of Technology Tianjin300384 China Tianjin Sino-German University of Applied Sciences Tianjin300384 China

ISBN: (纸本)9789819904501

When the bonding wire of IGBT module is aged, most traditional researches only consider the change rule of the electrothermal parameters caused by the number of dropped bonding wires, ignoring the influence caused by the difference of the distribution of the dropped bonding wires. Based on the temperature distribution coefficient k, the heat source offset caused by the bond wire falling off position is analyzed in this paper. Firstly, the temperature distribution coefficient k in the healthy state is determined by capturing the temperature at the bottom, middle and edge of the chip in a fixed position with a fiber grating sensor. Then, the FEM is used to analyze the heat source offset caused by the different number and location of bond wire falling off, and explore the law of temperature distribution coefficient k and heat source offset. Finally, an experimental platform is set up to verify the rule of heat source offset and temperature distribution coefficient k, and the specific bond wire falling off position is determined according to the values and changes of temperature distribution coefficient k on both sides of IGBT module. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Time parameter measurement system for alternating current filament relay of railway signal lamp 4

Time parameter measurement system for alternating current fi...

引用

4th International Conference on Advanced Electronic Materials, Computers and Software Engineering, AEMCSE 2021

作者： Zhang, Baofeng Pang, Tao Li, Zhiwei Zhu, Junchao Tianjin University of Technology Tianjin Key Lab. for Control Theory Application Complicated Systems and Biomedical Robot Laboratory Tianjin China

ISBN: (纸本)9781665415965

Aiming at the tedious maintenance work of ac filament conversion relay of railway signal lamp unit, this paper designs a new online detection device for relay working state. By switching relay paths and relying on the collected data, contact voltage image fitting is performed during the conversion process, and time parameters are extracted by different method to obtain the conversion time. Compared with the traditional detection device, the operation and detection time of the device is short, flexible and convenient. © 2021 IEEE.

关键词： Railroads

来源：评论

学校读者我要写书评

暂无评论

Machine Learning Classification of Riemannian Tangent Spaces Based on MI-BCI 20

Machine Learning Classification of Riemannian Tangent Spaces...

引用

20th IEEE International Conference on Mechatronics and Automation, ICMA 2023

作者： Zhao, Chunli Dong, Enzeng Tong, Jigang Yang, Sen Du, Shengzhi Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Intelligent Robot Laboratory 391 Binshui West Road Tianjin China Tshwane University of Technology Department of Electrical Engineering Pretoria0001 South Africa

ISBN: (纸本)9798350320831

Motor imagery brain-computer interfaces (BCIs) have been extensively used in stroke rehabilitation, particularly in China where stroke incidence is high. The application of BCI to control prostheses and robotic arms has shown promising results in improving the quality of life for stroke patients. However, a major challenge in this field is improving the accuracy of motor imagery (MI) classification. Several previous studies have reported that stroke patients exhibit atypical patterns of even-trelated desynchronization (ERD) and event-related synchronization (ERS) activation during motor imagery (MI) tasks. It has been suggested that the brain regions affected by stroke may show reduced excitability and relative insensitivity to external interference compared to those of healthy individuals. Therefore, this study proposes that the classification accuracy of stroke patients in the same MI task would be higher compared to that of healthy volunteers. In this study, we employed a feature extraction algorithm that combines the Filter Bank Common Spatial Pattern (FBCSP) and Riemann geometric mean distance methods to compare the classification accuracy of five different classifiers, with the objective of identifying the most suitable classifier for our analysis. The obtained results revealed that the K-Nearest Neighbors (KNN) classifier yielded the highest accuracy, reaching 87.5% for stroke patients and 85% for healthy volunteers, respectively. In addition to accuracy, we also utilized Kappa values as evaluation metrics, which yielded Kappa results of 0.619 and 0.613 for stroke patients and healthy volunteers, respectively. © 2023 IEEE.

关键词： Brain computer interface

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：