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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Zhengbin Shen Guihua Liu Chunmei Chen Yunxin Gong School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Southwest University of Science and Technology Mianyang China

Aiming at the problems of inaccurate and time-consuming manual detection of surface defects on high-voltage cable joints, a method for detecting surface defects on cable joints based on improved YOLOv5s is proposed. Firstly, (Space to Depth) SPD convolution and (Efficient Channel Attention) ECA attention mechanism are used in the feature extraction network to prevent the loss of information in tiny defects due to pooling operations. Secondly, a new multi-scale fusion feature pyramid structure is designed to better retain and fuse important information at each scale. Then the decoupling operation is performed on the detection head to avoid the conflict between the classification task and the localization task. Finally, the (Normalize Wasserstein Distance) DWN metric is used to design the localization loss to improve the ability of tiny defect localization. The experimental results show that the proposed method achieves 93.86% mAP in the cable joint surface defect dataset. Compared with the original algorithm, it improves 2.61% mAP, and at the same time reduces the number of parameters by 27.46% and the flops by 49.43%.

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Consensus Problem of Leader-following Second-order Multi-Agent Systems with Time-delay under Directed Topology

Consensus Problem of Leader-following Second-order Multi-Age...

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2021 International Conference on Intelligent Computing, Automation and applications, ICAA 2021

作者： Han, Qiang Tuo, Xianguo Zhou, Yongshuai Tang, Yuxin Southwest University of Science and Technology Robot Technology Used for Special Environment Key Laboratory of Sichuan Province 621010 China Sichuan University of Science Engineering Artificial Intelligent Key Laboratory of Sichuan Province School of Automation Information Engineering Zigong643000 China

ISBN: (纸本)9781665437301

In this paper, consensus problems of a kind of continuous-Time second-order MAS with communication delays is studied. A neighbor-based linear consensus protocol with time delay is introduced based on the fixed communication topology firstly, and then a necessary and sufficient condition for the system is derived based on graph theory and quadratic stability theory. An equality is proposed for obtaining the maximum time delay which is induced in the positions and velocities. Numerical simulations are carried out to further illustrate the effectiveness of the proposed theoretical results. © 2021 IEEE.

关键词： Time delay

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Using Load Transient Waveform to Analyze Fault Propagation Mechanism in DC-DC Switching Power Supply

Using Load Transient Waveform to Analyze Fault Propagation M...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Junliang Wan Pengfei Yu Qiang-Ming Cai Xin Cao Longjian Zhou Haoran Li Yuyu Zhu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Laboratory of Science and Technology on Reliability Physics and Application of Electronic Component Guangzhou China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

The degradation of certain components within DC-DC power supplies can lead to abnormal performance, resulting in the occurrence of faults. The degradation of components can cause changes in output voltage and current, and the different degradation characteristics of components have different impacts on the characteristics of output parameters. Therefore, it is necessary to master this impact relationship, that is, the fault propagation mechanism can be used to effectively diagnose faults and manage health. Studying the fault propagated mechanism is an important prerequisite for fault diagnosis. Output terminals of DC-DC power supply are usually connected in parallel with electrolytic capacitors. The function of electrolytic capacitors is to filter, filtering out most of the AC part of the output voltage, and reducing the ripple of the output voltage. Electrolytic capacitors are the most vulnerable components to failure in switching power supplies, with approximate 60% of failed components being electrolytic capacitors. Therefore, the fault propagation mechanism of electrolytic capacitors is a key research topic. Most research focuses on the fault propagation mechanism based on steady-state output signals. This article studies the fault propagation mechanism based on transient output signals. Through experimental testing, the impact of parameter degradation of electrolytic capacitors on the transient waveform of output voltage and the mapping relationship between capacitor degraded parameters and transient waveform are studied. The method is to analyze the voltage waveform when the current step changes using equivalent degradated experiments of capacitors. Its advantage lies in the fact that transient waveforms are more sensitive than steady-state waveforms and require lower sampling rates, making it easier to analyze the degradated characteristics of electrolytic capacitors. For power supplies with simple structures, data is collected through simulation. For commerc

关键词： Degradation Resistance Power supplies Capacitors Voltage Switches Capacitance

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Design of readout circuit for high sampling miniaturized MEMS wall shear force sensor

Design of readout circuit for high sampling miniaturized MEM...

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2022 International Symposium on Sensor technology and Control, ISSTC 2022

作者： Guo, ZhiJiang Guo, Hui Hui Liu, Tingting Gao, Yang School of Information Engineering Southwest University of Science and Technology Mianyang621010 China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang621010 China Microsystems Center Southwest University of Science and Technology Mianyang621010 China

Wall shear stress is one of the important measurement parameters in wind tunnel experiments. In the shock wind tunnel, the duration of the flow field is very short, usually a few milliseconds. To ensure measurement accuracy, the sampling rate should not be less than 1kHz. Due to the limitation of model volume and experimental environment, it is necessary to design a miniaturized readout circuit with high precision and high sampling rate, which is highly integrated with the MEMS wall shear stress sensor. The circuit includes a micro capacitance detection module integrated with the sensor head and a host computer signal processing and display module. Aiming at the complex measurement environment of the shock tunnel, to ensure the measurement accuracy, stability, and anti-interference ability of the weak capacitance detection circuit, a miniaturized ceramic substrate circuit is fabricated by a microstrip circuit process. The test results show that the resolution of the micro capacitance of the circuit can reach 20fF at the detection frequency of 3kHz, which can meet the measurement requirements of Shock tunnel, and realize the real-Time measurement and display of wall shear stress signal. © Published under licence by IOP Publishing Ltd.

关键词： Capacitance

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Theoretical calculation of high-pressure CO_(2)jet in cases of composite rock-breaking based on span-wagner equation of state

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Journal of Hydrodynamics 2022年第5期34卷 948-964页

作者： Xian-peng Yang Can Cai Xiao-hua Chen Pei Zhang Xin Zeng Chi Peng Yingfang Zhou Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan Province School of Mechanical EngineeringSouthwest Petroleum UniversityChengdu610500China School of Engineering University of AberdeenAberdeenUK Laboratory of High-pressure Jet Theory and Application Technology Southwest Petroleum UniversityChengdu610599China Key Laboratory of Groundwater Resources and Environment Ministry of EducationJilin UniversityChangchun130021China Southwest Pipeline Co. Ltd.National Pipe Network GroupChengdu610064China

Although several theoretical calculation methods for high-pressure jet are available,there is currently no theoretical model for the high-pressure CO_(2)jet based on the high-precision equation of state(EOS).To investigate the flow field of the high-pressure CO_(2)jet in cases of the composite rock-breaking under the high-pressure CO_(2)Jet and PDC cutter,a semi-analytical approach of the high-pressure CO_(2)jet is developed based on the Span-Wagner EOS and CO_(2)jet *** semi-analytical calculations and the physical property calculations under the action of the high-pressure CO_(2)jet are conducted with consideration of the jet pressure,the jet distance,the nozzle diameter and the jet *** results indicate that the distribution of the physical properties calculated by the semi-analytical approaches is similar to that obtained by experimental monitoring and numerical simulation,which indicates that the calculation method of the high-pressure CO_(2)jet presented in this paper is effective and *** properties of the CO_(2)jet obtained by the theoretical calculation see a significant difference between the initial region and the jet impact *** the temperature of 300 K,the increase of the initial pressure can effectively increase the impact force and the cooling ability of the *** proportion of the jet core lengths in the jet on the axis increases with the increase of the ratio of the nozzle diameter to the jet length,accompanied with the increase of the impact force of the *** increase of the jet angle can effectively increase the impacting force of the jet,but hampers the fluid *** study combines the theoretical calculation of the jet with the calculation of the physical properties of the high-pressure CO_(2),for comprehensively understanding the CO_(2)jet field in the composite rock-breaking under the action of the high-pressure CO_(2)jet and PDC *** theoretical calculation of the CO_(2)jet based on the high-precisio

关键词： CO_(2)jet hydraulic jet drill theoretical calculation equation of state(EOS) physical property

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Tailoring biochar by PHP towards the oxygenated functional groups(OFGs)-rich surface to improve adsorption performance

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Chinese Chemical Letters 2022年第6期33卷 3097-3100页

作者： Xinyue Xiong Zhanglin Liu Li Zhao Mei Huang Lichun Dai Dong Tian Jianmei Zou Yongmei Zeng Jinguang Hu Fei Shen Institute of Ecological and Environmental Sciences Sichuan Agricultural UniversityChengdu 611130China Rural Environment Protection Engineering&Technology Center of Sichuan Province Sichuan Agricultural UniversityChengdu 611130China Key Laboratory of Development and Application of Rural Renewable Energy Biogas Institute of Ministry of Agriculture and Rural AffairsChengdu 610041China Chemical and Petroleum Engineering Schulich School of Engineeringthe University of CalgaryCalgary T2N4H9Canada

In this work,a modification method of H_(3)PO_(4)plus H_(2)O_(2)(PHP)was introduced to targetedly form abundant oxygenated functional groups(OFGs)on biochar,and methylene blue(MB)was employed as a model pollutant for adsorption to reflect the modification *** indicated that parent biochars,especially derived from lower temperatures,substantially underwent oxidative modification by PHP,and OFGs were targetedly ***,approximately 21.5-fold MB adsorption capacity was achieved by PHP-modified biochar comparing with its parent *** evaluate the compatibility of PHP-modification,coefficient of variation(CV)based on MB adsorption capacity by the biochar from various precursors was calculated,in which the CV of PHP-modified biochars was 0.0038 comparing to0.64 of the corresponding parent *** results suggested that the PHP method displayed the excellent feedstock compatibility on biochar *** maximum MB adsorption capacity was454.1 mg/g when the H_(3)PO_(4)and H_(2)O_(2)fraction in PHP were 65.2%and 7.0%;the modification was further intensified by promoting temperature and ***,average 94.5%H_(3)PO_(4)was recovered after 10-batch modification,implying 1.0 kg H_(3)PO_(4)(85%)in PHP can maximally modify 2.37 kg ***,this work offered a novel method to tailor biochar towards OFGs-rich surface for efficient adsorption.

关键词： Biochar Oxidative modification Phosphoric acid Hydrogen peroxide Oxygenated functional groups

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Lethal pulmonary thromboembolism in mice induced by intravenous human umbilical cord mesenchymal stem cell-derived large extracellular vesicles in a dose-and tissue factor-dependent manner

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中国药理学报（英文版） 2024年第11期45卷 2300-2312页

作者： Bian-lei Yang Yao-ying Long Qian Lei Fei Gao Wen-xiang Ren Yu-lin Cao Di Wu Liu-yue Xu Jiao Qu He Li Ya-li Yu An-yuan Zhang Shan Wang Hong-xiang Wang Zhi-chao Chen Qiu-bai Li Department of Rheumatology and Immunology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Department of Hematology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China West China Biomedical Big Data Center West China HospitalSichuan UniversityChengdu 610041China Department of Hematology Key Laboratory for Molecular Diagnosis of Hubei ProvinceThe Central Hospital of WuhanTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430014China Department of Rheumatology and Immunology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Hubei Engineering Research Center for Application of Extracellular Vesicles Hubei University of Science and TechnologyXianning 437100China

Mesenchymal stem cell-derived extracellular vesicles(MSC-EVs)have obvious advantages over MSC *** the strong procoagulant properties of MSC-EVs pose a potential risk of thromboembolism,an issue that remains insufficiently *** this study,we systematically investigated the procoagulant activity of large EVs derived from human umbilical cord MSCs(UC-EVs)both in vitro and in ***-EVs were isolated from cell culture *** were injected with UC-EVs(0.125,0.25,0.5,1,2,4 μg/g body weight)in 100μL PBS via the tail *** and mortality were monitored for 30 min after *** showed that these UC-EVs activated coagulation in a dose-and tissue factor-dependent ***-EVs-induced coagulation in vitro could be inhibited by addition of tissue factor pathway ***,intravenous administration of high doses of the UC-EVs(1 μg/g body weight or higher)led to rapid mortality due to multiple thrombus formations in lung tissue,platelets,and fibrinogen depletion,and prolonged prothrombin and activated partial thromboplastin ***,we demonstrated that pulmonary thromboembolism induced by the UC-EVs could be prevented by either reducing the infusion rate or by pre-injection of heparin,a known *** conclusion,this study elucidates the procoagulant characteristics and mechanisms of large UC-EVs,details the associated coagulation risk during intravenous delivery,sets a safe upper limit for intravenous dose,and offers effective strategies to prevent such mortal risks when high doses of large UC-EVs are needed for optimal therapeutic effects,with implications for the development and application of large UC-EV-based as well as other MSC-EV-based therapies.

关键词： mesenchymal stem cells extracellular vesicles tissue factor coagulation pulmonary thromboembolism heparin

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Contactless Palmprint and Palm Vein Identity Recognition Via a Bimodal Network with Parameter-Adaptive Log-Gabor Convolution

SSRN

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SSRN 2023年

作者： Yang, Yang Zhou, Yingyue Huang, Runxia Liu, Qi He, Hongsen Li, Xiaoxia School of Information Engineering Southwest University of Science and Technology SiChuan Mianyang621010 China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Southwest University of Science and Technology SiChuan Mianyang621010 China

In recent years, biometric recognition based on palmprint and palm vein has become a hot research problem. However, there are still some challenges to realize the real-time contactless palm recognition, such as quickly locating the palm region of interest (ROI) in complex environments and designing the effective multi-modal feature extracting models, etc. In this paper, we use a binocular camera to simultaneously capture RGB and near-infrared (NIR) palm images. Then, ROIs of palmprint and palm vein images are located with the help of key point detection. Secondly, we design a lightweight bimodal feature extraction network, named LogPVNet which adopts a dual-branch parallel structure and incorporates parameter-adaptive Log-Gabor convolution and multi-receptive field feature map fusion modules, greatly improving the feature extraction ability. The experiment is conducted on TJU-PV and CASIA-PV datasets. The recognition accuracy is over 99.9% and the equal error rate (EER) reduces to the value below 0.01%. © 2023, The Authors. All rights reserved.

关键词： Convolution

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Radiation Resistant Imaging System Based on Conductive Optics

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Yuanzineng Kexue Jishu/Atomic Energy Science and technology 2025年第5期59卷 1135-1144页

作者： Ma, Fengjuan Deng, Hao Liu, Guihua Zhao, Junqin Southwest University of Science and Technology Mianyang621010 China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang621010 China Mianyang Teachers’ College Mianyang621000 China China Aerodynamics Research and Development Center Mianyang621006 China

Due to the effects of Compton scattering by high-energy γ-photons and the total dose, existing integrated CIS imaging systems have very short lifespans in strong radiation environments, severely limiting their ability to perform tasks such as γ-radiation scene monitoring and scene perception. Therefore, this paper addresses the issue of the short lifespan of CMOS image sensors in high-radiation environments by designing a radiation-resistant imaging system based on conductive optics. The goal is to enhance radiation resistance, optimize imaging performance, simplify the optical system layout, and improve system reliability, ensuring effective application in radiation scene monitoring and other safety-related tasks. Firstly, a passive light-receiving front-end was constructed using fiber-optic imaging bundles to transmit the optical representation of the scene to the imaging back-end at low irradiation dose rates. The passive light-receiving front-end objective lens consists of eight lenses. Lenses 1 and 2 expand the field of view to collect more light. Lens 3 has a negative focal length, converging and effectively reducing the field of view of the rear group. The doublet lenses placed behind the aperture primarily correct chromatic aberration and field curvature of the entire optical system. The final two lenses receive the light and focus it onto the incident face of the fiber-optic bundle, ensuring that the image height matches the size of the fiber-optic bundle’s end face. The light-receiving front-end uses radiation-resistant optical materials, while the imaging back-end is made from radiation-shielding optical materials. This dual approach of radiation-resistant at the front and radiation-shielding at the rear helps reduce both the loss of light reception performance and the degradation rate of the lifespan of electronic components. The radiation-resistant optical materials mitigate optical color shifts in radiation environments, thereby reducing light receptio

关键词： Electromagnetic shielding

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An Erasure Code with Low Repair-Cost Based on A Combined-stripe Encoding Structure

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International Journal of Network Security 2024年第2期26卷 206-216页

作者： Sun, Minjun Tang, Dan Li, Yue Wang, Xie Cai, Hongliang Zeng, Qiong School of Software Engineering Chengdu University of Information Technology China Sichuan Province Engineering Technology Research Center of Support Software of Informatization Application China Key Laboratory of Sichuan University for Aviation Manufacturing and Ground Command Software Chengdu610225 China

As a commonly used data redundancy strategy, erasure codes can effectively improve storage efficiency. However, the more network bandwidth consumed during repair, the more it limits its practical application in distributed storage systems. To solve the problem of high repair costs of erasure codes, this paper proposes an erasure code-named combined-stripe local reconstruction codes (CSLRC). CSLRC generates local parity blocks for redundancy protection by adding appropriate redundancy and using combined-stripe coding. CSLRC can flexibly configure coding parameters to balance storage overhead and repair costs better. Experimental results show that CSLRC can significantly reduce the amount of data to be read and transmitted during the repair process while maintaining high fault tolerance, saving network bandwidth and I/O resources, and effectively shortening repair time compared with other erasure codes. © (2024), (Femto Technique Co.). All Rights Reserved.

关键词： Redundancy

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