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基于稀疏贝叶斯学习的混合mMIMO系统波达方向估计

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数据采集与处理 2024年第5期39卷 1260-1270页

作者：慕欣茹傅海军戴继生东华大学信息科学与技术学院上海201620 江苏大学电气信息工程学院镇江212013

波达方向估计是混合mMIMO系统波束成形得以应用的前提,基于协方差矩阵重构的子空间方法在相干信号和有限快拍数条件下性能损失较大。为了应对上述挑战,提出了一种基于稀疏贝叶斯学习的混合mMIMO系统波达方向估计方法,主要创新之处在于:... 详细信息

波达方向估计是混合mMIMO系统波束成形得以应用的前提,基于协方差矩阵重构的子空间方法在相干信号和有限快拍数条件下性能损失较大。为了应对上述挑战,提出了一种基于稀疏贝叶斯学习的混合mMIMO系统波达方向估计方法,主要创新之处在于:将混合mMIMO系统的波达方向估计问题转化为稀疏信号恢复问题,从而绕过空间协方差矩阵重构,避免了其带来的性能损失。为了便于进行贝叶斯推断,进一步利用变分贝叶斯近似思想,在恢复稀疏信号的同时,自适应估计出未知参数,显著改善了对噪声和相干信号的鲁棒性,提升了有限快拍数情况下的波达方向估计性能。数值模拟结果验证了所提方法的优越性。

关键词：波达方向估计模数混合结构大规模多输入多输出系统稀疏贝叶斯学习变分贝叶斯推断

A review of electrical signal-based train transmission machinery diagnosis technology

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Transportation Safety and Environment 2021年第3期3卷 179-195页

作者： jisheng dai Rongjun Ding Zhaoyi Guan Shaolong Xu College of Mechanical and Vehicle Engineering Hunan Universitychangsha410082China CRRC Zhuzhou Electric Locomotive Research Institute Co. zhuzhou412000China School of Traffic and Transportation Engineering Central South UniversityChangsha410075China

Transmission machinery is widely used in railway vehicles and is an important component in driving the operation of *** transmission components are prone to faults under long exposure to harsh environments and complex working *** affects normal operation and order,and thus it is important to ensure their safe and reliable *** signal-based diagnosis technology has advantages of easy signal acquisition,with no need to install additional sensors,nor embedded monitoring of the object *** has gradually become a research hotspot in the field of rail transportation *** paper describes the fault modes of transmission machinery,takes the electrical signal-based diagnosis method as the entry point,collates and compares the existing diagnosis methods and research results in this *** analyses their advantages and disadvantages,and finally puts forward problems for current and future research and development.

关键词： transmission machinery fault diagnosis bearing gear machine learning signal processing rail transportation

Review and prospect of maintenance technology for traction system of high-speed train

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Transportation Safety and Environment 2021年第3期3卷 196-215页

作者： Shaolong Xu Chunyang Chen Zhenjun Lin Xiao Zhang jisheng dai Liangjie Liu School of Traffic and Transportation Engineering Central South UniversityChangshaHunan 410075China Zhuzhou CRRC Times Electric Co. Ltd.ZhuzhouHunan 412001China College of Mechanical and Vehicle Engineering Hunan UniversityChangshaHunan 410082China Zhuzhou CRRC Times Electric UK Innovation Center 2650 Kings CourtB377YEBirmingham

In the past few decades,high-speed trains have witnessed tremendous and vigorous development with the appearance of the oil crisis and industrialization,which became a significant trend in the transportation industry the world *** the increase of high-speed railway mileage,the amount of high-speed train has grown sharply,the service life of the trains has increased gradually and the components of the vehicle traction system have become worn and aged as a ***,advanced maintenance technology and its application are key factors to reduce maintenance cost,human resource input and ensure safe,stable and reliable operation of *** paper summarizes and discusses the development,application mode,maintenance management and maintenance technology of high-speed railways of the major countries in the world,especially discusses the condition-based maintenance and the key technology of the traction electrical system,and offers the prospect of research direction and the development of traction maintenance technology.

关键词： high-speed railway traction system maintenance technology condition assessment life prediction condition-based maintenance Prognostic and health management(PHM)

Multi-component system maintenance optimization of a rail transit train based on opportunistic correlations

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Transportation Safety and Environment 2023年第4期5卷 182-191页

作者： jisheng dai Rongjun Ding Yong Fu Yong Qin College of Mechanical and Vechicle Engineering Hunan UniversityYuelu DistrictChangshaHunan 410082China Zhuzhou CRRC Times Electric Co. Ltd.Shifeng DistrictZhuzhouHunan 412001China State Key Lab of Rail Traffic Control&Safety Beijing Jiaotong UniversityHaidian DistrictBeijing 100044China

ln order to deal with the problems of insufficient or excessive maintenance in the current maintenance activities of China transit trains,this paper develops a novel multi-component system maintenance optimization approach based on an opportunistic correlation *** on the minimal reliability and failure rate change rule of each train component,the novel proposed maintenance optimization benefits from an improved opportunistic maintenance model with system structure correlation,fault correlation and reliability correlation under imperfect ***,different maintenance modes can be determined by a proposed mainte-nance factor under the different conditions of ***,the reliability threshold of each component is also considered to optimize the maintenance cost by the system reliability and operational availability of the ***,as the mentioned problem belongs to the NP-Hard optimization problems,a modified particle swarm optimization(PSO)with the improvement of inertia weight is proposed to cope with the optimization *** on a specific case under the practical recorded failure data,the analysis shows that the proposed model and approach can effectively cut the maintenance cost.

关键词： multi-component system maintenance optimization rail transit train opportunistic correlation modified particle swarm optimization(PSO)

基于深度高斯过程的永磁牵引电机匝间短路分级评估方法

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机车电传动 2024年第2期 108-117页

作者：戴计生胡德安徐海龙朱文龙廖启术湖南大学机械与运载工程学院湖南长沙410082 株洲中车时代电气股份有限公司湖南株洲412001

定子绕组匝间短路是影响永磁牵引电机安全稳定运行的主要故障之一,受运行工况、供电与电机本体不平衡的影响,现有方法难以实现永磁牵引电机匝间短路在线精准评估,这成为永磁电机推广应用迫切需要解决的关键技术难题。因此,文章提出一种... 详细信息

定子绕组匝间短路是影响永磁牵引电机安全稳定运行的主要故障之一,受运行工况、供电与电机本体不平衡的影响,现有方法难以实现永磁牵引电机匝间短路在线精准评估,这成为永磁电机推广应用迫切需要解决的关键技术难题。因此,文章提出一种基于多特征融合的深度高斯过程永磁牵引电机匝间短路分级评估方法:首先通过建立永磁牵引电机匝间短路故障模型,提取电流不平衡、电流三次谐波与dq电流的二次谐波特征;然后采用一种双随机变分推断深度高斯过程(Doubly Stochastic Deep Gaussian Processes,DSDGP)方法对提取特征进行融合训练建模,实现永磁牵引电机匝间短路劣化状态在线分级评估;最后通过永磁电机匝间短路试验与现场案例进行算法验证。结果表明,文章所提方法在多特征融合条件下的评估准确率达到95%以上,相较于支持向量机(support vector machine,SVM)和反向传播神经网络(back-propagation neural,BPN)等分类方法,具有准确率高,适用于变工况、小样本的工程实际应用环境等优点,解决了永磁牵引电机匝间短路早期故障检测及故障严重程度评估的行业难题。

关键词：永磁牵引电机多维特征融合匝间短路分级评估深度高斯过程

未知互耦下双基地MIMO雷达阵列DOD和DOA估计算法

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数据采集与处理 2016年第4期31卷 713-718页

作者：戴继生汪洋叶中付江苏大学电气信息工程学院镇江212013 中国科学技术大学电子工程与信息科学系合肥230027

针对MIMO雷达阵列中存在的互耦效应会严重影响发射角(DOD)和接收角(DOA)估计性能的问题,提出了一种基于ESPRIT算法的双基地MIMO雷达阵列DOA和DOD估计方法。该方法利用阵列流型矩阵的结构特点和均匀线阵互耦矩阵的带状Toeplitz特性,能实... 详细信息

针对MIMO雷达阵列中存在的互耦效应会严重影响发射角(DOD)和接收角(DOA)估计性能的问题,提出了一种基于ESPRIT算法的双基地MIMO雷达阵列DOA和DOD估计方法。该方法利用阵列流型矩阵的结构特点和均匀线阵互耦矩阵的带状Toeplitz特性,能实现互耦效应未知情况下DOA和DOD的精确估计。本文方法无需对角度进行搜索,计算量小,对角度的估计精度高,特别是在低信噪比环境下依然能取得较好的估计性能。仿真结果验证了本算法的可行性和正确性。

关键词：阵列信号处理 MIMO雷达互耦接收角估计发射角估计

一种基于实值变分贝叶斯推断的大规模MIMO系统下行信道估计方法

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数据采集与处理 2021年第6期36卷 1094-1103页

作者：戴继生尚河坤江苏大学电气信息工程学院镇江212013

酉矩阵变换是一种常用的实值化方法,可有效地降低计算复杂度。然而,在现有的基于酉矩阵变换的大规模多输入多输出系统(Multiple input multiple output,MIMO)下行信道估计方法中,观测矩阵的维度增加了一倍,若不进行维度压缩,降低计算复... 详细信息

酉矩阵变换是一种常用的实值化方法,可有效地降低计算复杂度。然而,在现有的基于酉矩阵变换的大规模多输入多输出系统(Multiple input multiple output,MIMO)下行信道估计方法中,观测矩阵的维度增加了一倍,若不进行维度压缩,降低计算复杂度的目标将难以实现。虽然利用信号空间和噪声空间的正交性可压缩维度,但信号空间只能近似计算获得,不可避免地带来性能损失。为了改善信道估计性能,本文将信号空间矩阵当作变量,在估计过程中自适应地调整信号空间矩阵,但这使得信号空间矩阵和稀疏信号矩阵高度耦合,传统的贝叶斯推断无法适用。为了应对该挑战,本文进一步引入列向量独立分解的贝叶斯变分假设,成功将信号空间矩阵和稀疏信号矩阵解耦。仿真结果表明,所提方法可显著提升信道估计性能。

关键词：大规模多输入多输出信道估计实值转换变分贝叶斯推理稀疏信号恢复

Characterization of sand convective motions at a vertical wall subjected to long-term cyclic loading

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Fundamental Research 2024年第2期4卷 334-343页

作者： Dawei Guan Jialong Li Yee-Meng Chiew jisheng Zhang Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210024China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210024China Shanghai Investigation Design and Research Institute Co.LtdShanghai 200335China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

By conducting a two-dimensional experimental study,this paper aims to enhance the understanding of the mechanism of sand convective motions in the vicinity of a wall subjected to long-term cyclic lateral *** experimental tests were conducted in a rectangular sandbox with a transparent front-wall,through which the process of sand particle motions could be recorded by using a high-resolution digital *** images were processed with a high time-resolved PIV(Particle Image Velocimetry)*** on the experimental data,this work(1)presents the sand flow field in the convective zones;(2)provides means to describe the convection mechanism;(3)proposes the relationships between the loading conditions and dimensions of the region with intense sand movement;and(4)elaborates the similarity of the sand flow velocity structure within the sand convective zones.

关键词： Vibration Soil/structure interaction Deformation Particle image velocimetry Laboratory tests

Red blood cell membrane-coated FLT3 inhibitor nanoparticles to enhance FLT3-ITD acute myeloid leukemia treatment

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Chinese Chemical Letters 2024年第9期35卷 303-308页

作者： jisheng Liu Junli Chen Xifeng Zhang Yin Wu Xin Qi Jie Wang Xiang Gao Department of Neurosurgery and Institute of Neurosurgery State Key Laboratory of Biotherapy and Cancer CenterWest China HospitalWest China Medical SchoolSichuan UniversityChengdu 610041China West China School of Basic Medical Sciences&Forensic Medicine Sichuan UniversityChengdu 610041China Department of Hematology West China HospitalSichuan UniversityChengdu 610041China

FMS-like tyrosine kinase 3(FLT3)is a viable and important therapeutic target for acute myeloid leukemia(AML).FLT3 internal tandem duplication(FLT3-ITD)mutations have been identified in approximately 30%of AML patients,and are associated with unfavorable prognosis,higher risk of relapse,drug resistance,and poor clinical *** FLT3 inhibitors have demonstrated promising efficacy,they cannot cure AML or even significantly extend the lives of patients with FLT3-ITD *** is partly because of poor water solubility,insufficient membrane penetration and short half-life of small molecule ***,the presence of enzymes like CYP3A4 in bone marrow accelerate the elimination and metabolism of FLT3 inhibitors,resulting in low plasma concentrations and side *** we report the erythrocyte membrane-camouflaged FLT3 inhibitor nanoparticles to enhance FLT3-ITD AML ***,we physically coextruded red blood cell(RBC)membrane vesicles with nanoparticles derived from FLT3 inhibitor F30 to obtain F30@RBC-M,which exhibited comparable potent FLT3-ITD inhibitory effects compared to free F30 in vitro,while displaying a higher potent antitumor efficacy in xenograft models due to the prolonged circulation ***,administration of F30@RBC-M significantly extended the survival of mice in a transplanted mouse model than F30 free *** findings suggest that RBC membrane-coated nanoparticles derived from FLT3 inhibitors hold promise as a tool to enhance the therapeutic efficacy to treat FLT3-ITD AML.

关键词： FLT3-ITD Acute myeloid leukemia AML Red blood cell membrane Biomimetics