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广播电视发射台站备用电源系统设计与优化

电视技术 2024年第6期48卷 62-65页

作者：胡玉梅北京市密云区融媒体中心北京101500

备用电源系统能够有效降低因供配电系统故障导致的播出事故的概率,是广播电视发射台站安全播出的重要保证。以广播电视台发射台站供配电改造工程为例,提出一套改进型备用电源系统设计方案,利用PC817光电耦合器实时检测掉电因子,并以外... 详细信息

备用电源系统能够有效降低因供配电系统故障导致的播出事故的概率,是广播电视发射台站安全播出的重要保证。以广播电视台发射台站供配电改造工程为例,提出一套改进型备用电源系统设计方案,利用PC817光电耦合器实时检测掉电因子,并以外围接口控制器(Peripheral Interface Controller,PIC)系列单片机作为主控制器来调节切换装置,以实现备用电源系统的自主优化。

关键词：广播电视发射台站备用电源光电耦合器单片机

Water quality characteristics and assessment of Yongding New River by improved comprehensive water quality identification index based on game theory

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Journal of Environmental Sciences 2021年第6期33卷 40-52页

作者： Yu Liu Yucheng hu yumei hu Yuqi Gao Zhenying Liu School of Earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China Tianjin Hydraulic Science Research Institute Tianjin 300061China School of Mathematics Tianjin UniversityTianjin 300072China School of Environmental Science and Safety Engineering Tianjin University of TechnologyTianjin 300191China

The Yongding New River is essential for the water supplies of *** date,there is no comprehensive report that assesses the year-round water quality of the Yongding New River Main ***,little attention has been given to determining a combined weight for improving the traditional comprehensive water quality identification index(ICWQII)by the game *** water quality parameters were investigated monthly along the main stream of the Yongding New River from May 2018 to April *** contaminants and nitrogen pollution were mainly caused by point sources pollution,and the total phosphorus mainly by non-point source *** spatio-temporal variations of water quality parameters were jointly caused by different pollutant sources and hydrometeorological *** terms of this study,an improved comprehensive water quality identification index(ICWQII)based on entropy weight or variation coefficient and traditional CWQII underestimated the water qualities,and an ICWQII based on the superstandard multiple method overvalued the *** contrast,water qualities assessments done with an ICWQII based on the game theory matched perfectly with the practical *** ICWQII based on game theory proposed in this study takes into account not only the degree of disorder and variation of water quality data,but also the influence of standard-exceeded pollution indicators,whose results are relatively *** findings and the ICWQII based on game theory can provide scientific support for decisions related to the water environment management of the Yongding New River and other waters.

关键词： Water quality assessment Improved comprehensive water quality identification index Game theory Combined weight Spatio-temporal variation Yongding New River

Variational Bayesian Kalman filter using natural gradient

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Chinese Journal of Aeronautics 2022年第5期35卷 1-10页

作者： yumei hu Xuezhi WANG Quan PAN Zhentao hu Bill MORAN School of Automation Northwestern Polytechnical UniversityXi’an 710072China The Key Laboratory of Information Fusion Technology Ministry of EducationXi’an 710072China Department of Electrical and Electronic Engineering The University of MelbourneMelbourneVIC 3010Australia School of Engineering RMIT UniversityMelbourneVIC 3000Australia School of Computer and Information Engineering Henan UniversityKaifeng 475001China

We propose a technique based on the natural gradient method for variational lower bound maximization for a variational Bayesian Kalman *** natural gradient approach is applied to the Kullback-Leibler divergence between the parameterized variational distribution and the posterior density of *** a Gaussian assumption for the parametrized variational distribution,we obtain a closed-form iterative procedure for the Kullback-Leibler divergence minimization,producing estimates of the variational hyper-parameters of state estimation and the associated error *** results in both a Doppler radar tracking scenario and a bearing-only tracking scenario are presented,showing that the proposed natural gradient method outperforms existing methods which are based on other linearization techniques in terms of tracking accuracy.

关键词： Kullback-Leibler divergence Natural gradient Nonlinear Kalman filter Target tracking Variational Bayesian optimization

“双线混融教学”情景下公司金融课程的研究导向型教学设计

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金融理论与教学 2024年第2期42卷 112-118页

作者：胡玉梅张国建南京审计大学金融学院江苏南京211815 南京审计大学联合研究院江苏南京211815 南京审计大学经济学院江苏南京211815

外界环境的不确定性变化和信息技术的飞跃发展给高校金融类课程教学提出了更高的要求。传统的教学模式不能完全适应新时代金融类教学发展的需要,“双线混融教学”情景下的研究导向型教学是必然趋势。在研究导向型教学模式下,双线混融教... 详细信息

外界环境的不确定性变化和信息技术的飞跃发展给高校金融类课程教学提出了更高的要求。传统的教学模式不能完全适应新时代金融类教学发展的需要,“双线混融教学”情景下的研究导向型教学是必然趋势。在研究导向型教学模式下,双线混融教学应以培养学生自主学习和发现问题解决问题的能力为导向,通过提高学生独立思考能力、信息检索和筛选能力、创新能力,培育综合型高水平的金融人才。通过对“双线混融教学”情景下研究导向型教学内涵、必要性和教学设计要点进行分析,以期为实施研究导向型的公司金融课程教学提供有益参考。

关键词：双线混融教学研究导向型教学公司金融教学设计

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复杂系统智能授时管理方法

信息技术与信息化 2024年第3期 99-102页

作者：张妍典胡玉梅中国航空工业集团公司西安航空计算技术研究所陕西西安710000

现有授时设备虽然支持内置高精度时钟源以及GPS/北斗卫星授时,但面对高度复杂电磁环境的军事训练评估场景,可能由于强干扰、高阻塞等原因导致授时基准源信息获取失败,进而引起整体系统失效风险。针对上述问题,提出一种多时统源的智能授... 详细信息

现有授时设备虽然支持内置高精度时钟源以及GPS/北斗卫星授时,但面对高度复杂电磁环境的军事训练评估场景,可能由于强干扰、高阻塞等原因导致授时基准源信息获取失败,进而引起整体系统失效风险。针对上述问题,提出一种多时统源的智能授时管理方法。在实现方法中,首先以FPGA系统时钟作为基准对输入时统源进行有效性分析;然后基于分析结果进行授时智能仲裁选通,以支持系统运行期间时统源的随时切换,保证系统运行的稳定性和精确性,为复杂系统的抗干扰性和可靠性提供有效支撑。所提出的方法已在某军事训练评估系统中部署使用,并长期稳定运行。

关键词：时统系统卫星授时 FPGA 智能授时

Gearbox Deterioration Detection under Steady State,Variable Load, and Variable Speed Conditions

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 256-264页

作者： SHAO Yimin CHRIS K Mechefske OU Jiafu hu yumei State Key Laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China Department of Mechanical and Materials Engineering Queen＇s University Canada China Chongqing Automobile Research Institute Chongqing 400039 China

Multiple dominant gear meshing frequencies are present in the vibration signals collected from gearboxes and the conventional spiky features that represent initial gear fault conditions are usually difficult to detect. In order to solve this problem, we propose a new gearbox deterioration detection technique based on autoregressive modeling and hypothesis testing in this paper. A stationary autoregressive model was built by using a normal vibration signal from each shaft. The established autoregressive model was then applied to process fault signals from each shaft of a two-stage gearbox. What this paper investigated is a combined technique which unites a time-varying autoregressive model and a two sample Kolmogorov-Smimov goodness-of-fit test, to detect the deterioration of gearing system with simultaneously variable shaft speed and variable load. The time-varying autoregressive model residuals representing both healthy and faulty gear conditions were compared with the original healthy time-synchronous average signals. Compared with the traditional kurtosis statistic, this technique for gearbox deterioration detection has shown significant advantages in highlighting the presence of incipient gear fault in all different speed shafts involved in the meshing motion under variable conditions.

关键词： gearbox condition detection hypothesis test time-varying autoregressive(AR) modeling Kolmogorov-Smimov goodness-of-fit test

Gaussian-Student's t mixture distribution PHD robust filtering algorithm based on variational Bayesian inference

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High Technology Letters 2022年第2期28卷 181-189页

作者： hu Zhentao YANG Linlin hu yumei YANG Shibo School of Artificial Intelligence Henan UniversityZhengzhou 450046P.R.China School of Automation Northwestern Polytechnical UniversityXi'an 710029P.R.China

Aiming at the problem of filtering precision degradation caused by the random outliers of process noise and measurement noise in multi-target tracking(MTT) system,a new Gaussian-Student’s t mixture distribution probability hypothesis density(PHD) robust filtering algorithm based on variational Bayesian inference(GST-vbPHD) is ***,since it can accurately describe the heavy-tailed characteristics of noise with outliers,Gaussian-Student’s t mixture distribution is employed to model process noise and measurement noise *** Bernoulli random variable is introduced to correct the likelihood distribution of the mixture probability,leading hierarchical Gaussian distribution constructed by the Gaussian-Student’s t mixture distribution suitable to model non-stationary ***,the approximate solutions including target weights,measurement noise covariance and state estimation error covariance are obtained according to variational Bayesian inference *** simulation results show that,in the heavy-tailed noise environment,the proposed algorithm leads to strong improvements over the traditional PHD filter and the Student’s t distribution PHD filter.

关键词： multi-target tracking(MTT) variational Bayesian inference Gaussian-Student’s t mixture distribution heavy-tailed noise

Facile synthesis of high electrical conductive CoP via solid-state synthetic routes for supercapacitors

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Journal of Energy Chemistry 2017年第1期26卷 49-55页

作者： yumei hu Maocheng Liu Qingqing Yang Lingbin Kong Long Kang State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of TechnologyLanzhou 730050GansuChina School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050GansuChina

Co-P precursor was prepared by a mechanical alloying method and then is controlled to synthesis of CoP phase through an annealing method. The optimal conditions of ball milling and annealing temperature are investigated. The CoP exhibits higher electrical conductivity than graphite and cobalt oxide, showing excellent pseudocapacitive properties due its high electrical conductivity which can result in a fast electron transfer in high rate charge-discharge possess. The as-obtained CoP electrode achieves a high specific capacitance of 447.5 Fig at 1 Aug, and displays an excellent rate capability as well as good cycling stability. Besides, the asymmetric supercapacitor (ASC) based on the CoP as the positive electrode and activated carbon (AC) as the negative electrode was assembled and displayed a high rate capability (60% of the capacitance is retained when the current density increased from 1 Aug to 12 Aug), excellent cycling stability (96.7% of the initial capacitance is retained after 5000 cycles), and a superior specific energy of 19 Wh/kg at a power density of 350.8 W/kg. The results, suggest that the CoP electrode materials have a great potential for developing high-performance electrochemical energy storage devices. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

关键词： CoP High electrical conductivity Pseudocapacitive properties Asymmetric supercapacitor

Marginalized cubature Kalman filtering algorithm based on linear/nonlinear mixed-Gaussian model

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High Technology Letters 2018年第4期24卷 362-368页

作者： hu yumei hu Zhentao Jin Yong School of Automation Northwestern Polytechnical University College of Computer and Information Engineering Henan University

Aiming at improving the estimation accuracy and real-time of nonlinear system with linear Gaussian sub-structure,a novel marginalized cubature Kalman filter is proposed in Bayesian estimation framework. Firstly,the marginalized technique is adopted to model the target system dynamics with nonlinear state and linear state separately,and the two parts are estimated by cubature Kalman filter and standard Kalman filter respectively. Therefore,the linear part avoids the generation and propagation process of cubature points. Accordingly,the computational complexity is ***,the accuracy of state estimation is improved by taking the difference of nonlinear state estimation as the measurement of linear state. Furthermore,the computational complexity of marginalized cubature Kalman filter is discussed by calculating the number of floating-point operation. Finally,simulation experiments and analysis show that the proposed algorithm can improve the performance of filtering precision and real-time effectively in target tracking system.

关键词： state estimation marginalized modeling mixed-Gaussian model cubature Kalman filter