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Condition Monitoring for Railway Point Machines Based on Sound Analysis and Support Vector Machine

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Chinese Journal of Electronics 2020年第4期29卷 786-792页

作者： SUN Yongkui CAO Yuan xie guo WEN Tao School of Electronic and Information Engineering Beijing Jiaotong University National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology

Railway point machines(RPMS) are one of the key equipments in the railway system to switch different routes for the *** monitoring for RPMs is a vital measure to keep train operation safe and *** convenience and low cost into consideration, a novel intelligent condition monitoring method for RPMs based on sound analysis is ***-domain and frequency-domain features are obtained,and normalized using z-score standardization method to eliminate the influences of different *** particle swarm optimization(BPSO) is utilized to select the most significant discrimination feature *** effects of the selected optimal features are verified using Support vector machine(SVM), 1-Nearest neighbor(1 NN), Random forest(RF), and Naive Bayes(NB).Experiment results indicate SVM performs best on identification accuracy and computing cost compared with the other three *** identification accuracies on normal switching and reverse switching processes reach100% and 99.67%, respectively, indicating the feasibility of the proposed method.

关键词： Condition monitoring Sound analysis Railway point machines(RPMs) Binary particle swarm optimization(BPSO) Support vector machine(SVM)

Novel methanol-tolerant Ir-S/C chalcogenide electrocatalysts for oxygen reduction in DMFC fuel cell

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Particuology 2011年第2期9卷 155-160页

作者： Jingyu Ma Desheng Ai Xiaofeng xie Jianwei guo Institute of Nuclear & New Energy Technology Tsinghua University Beijing 100084 China

Novel methanol-tolerant oxygen-reduction catalysts, iridium-sulphur （Ir-S） chalcogenides with different Ir/S atomic ratios, were synthesized via a precipitation method using H2IrCI6 and Na2SO3 as the Ir and S precursors. Powder X-ray diffraction （XRD） and transmission electron microscopy （TEM） were used to characterize the lrxSl_x/C chalcogenide catalysts. Particle size ranging from 2.5 to 2.8 nm though obvi- ous agglomeration was found on carbon support. However, these chalcogenide catalysts showed strong catalytic activity towards the oxygen reduction reaction （ORR） and high methanol tolerance, strongly suggesting these novel catalysts as promising candidates for direct methanol fuel cell （DMFC） cathode applications.

关键词： DMFCIridiumSulphurCathodic catalystOxygen reductionMethanol tolerant

Robust adaptive control for dynamic systems with mixed uncertainties

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Journal of Systems Engineering and Electronics 2016年第3期27卷 656-663页

作者： Jiaoru Huang Fucai Qian guo xie Hengzhan Yang School of Automation and Information Engineering Xi'an University of Technology Key Laboratory of Spacecraft In-orbit Fault Diagnosis and Repair Xi'an Satellite Control Center

The control problem for single-input single-output（SISO） systems in the presence of mixed uncertainties, both stochastic and deterministic uncertainties, is considered. The stochastic uncertainties are modeled as exogenous noises, while the deterministic uncertainties are time invariant and appear as the unknown parameters which lie in a bounded interval. Based on a subdivision for the continuous interval, a robust adaptive controller is designed. The controller can not only realize the system output to track the desired output, but also learn a more accurate interval which contains the true value of the unknown parameter with a learning error given in advance. An example is given finally to demonstrate the effectiveness of the proposed method.

关键词： stochastic uncertainties deterministic uncertainties minimum variance control robust control robust adaptive control

Construction and analysis of dynamic solidification curves for non-equilibrium solidification process in lost-foam casting hypoeutectic gray cast iron

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China Foundry 2017年第3期14卷 176-183页

作者： Ming-guo xie Chang-an Zhu School of Engineering Science University of Science and Technology of China Hefei 230026 China

Most lost-foam casting processes involve non-equilibrium solidification dominated by kinetic factors, while construction of a common dynamic solidification curve is based on pure thermodynamics, not applicable for analyses and research of non-equilibrium macro-solidification processes, and the construction mode can not be applied to nonequilibrium solidification process. In this study, the construction of the dynamic solidification curve(DSC) for the nonequilibrium macro-solidification process included: a modified method to determine the start temperature of primary austenite precipitation(T_(AL)) and the start temperature of eutectic solidification(T_(ES)); double curves method to determine the temperature of the dendrite coherency point of primary austenite(T-(AC)) and the temperature of eutectic cells collision point(T_(EC)); the "technical solidus" method to determine the end temperature of eutectic reaction(T_(EN)). For this purpose, a comparative testing of the non-equilibrium solidification temperature fields in lost-foam casting and green sand mold casting hypoeutectic gray iron was carried out. The thermal analysis results were used to construct the DSCs of both these casting methods under non-equilibrium solidification conditions. The results show that the transformation rate of non-equilibrium solidification in hypoeutectic gray cast iron is greater than that of equilibrium solidification. The eutectic solidification region presents a typical mushy solidification mode. The results also indicate that the primary austenite precipitation zone of lost-foam casting is slightly larger than that of green sand casting. At the same time, the solid fraction(f_s) of the dendrite coherency points in lost-foam casting is greater than that in the green sand casting. Therefore, from these two points, lost-foam casting is more preferable for reduction of shrinkage and mechanical burntin sand tendency of the hypoeutectic gray cast iron. Due to the fact that the solidifica

关键词： hypo-eutectic gray cast iron lost-foam casting non-equilibrium solidification process dynamic solidification curve

Optimizing Strength and Ductility of Titanium Alloys by Oxygen: Review and Prospect

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Chinese Journal of Structural Chemistry 2020年第4期39卷 615-622页

作者： CAI Ze-Yun LI Kun xie guo-Qiang School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055China

The traditional strengthening elements of titanium alloys include Al,Mo,V,etc.,however,the high cost and toxicity of these elements put a limit on their further applications for *** light elements such as oxygen are hopeful replacement due to high *** is recognized that the oxygen enhances the strength but pays the price of brittleness,thus the amount of oxygen is ***,recent study results indicated that excess oxygen can keep high ductility together with high strength of *** paper reviews the influence and the mechanism of oxygen on the strength and ductility of titanium alloys,and provides a new perspective for the strengthening method of titanium alloys.

关键词： oxygen strength ductility titanium alloy

基于UCTransNet的建筑损害评估模型

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计算机工程与设计 2025年第1期46卷 44-51页

作者：谢国波张文亮何林林志毅广东工业大学计算机学院广东广州510006

为提高建筑损害的评估精度,提出一种基于UCTransNet的双阶段灾后建筑损害评估模型(MGDLNet)。阶段一使用UCTransNet完成建筑分割。阶段二使用改进后的DM-UCTransNet进行建筑损害评估,通过差异特征提取模块充分融合多尺度的建筑损害特征... 详细信息

为提高建筑损害的评估精度,提出一种基于UCTransNet的双阶段灾后建筑损害评估模型(MGDLNet)。阶段一使用UCTransNet完成建筑分割。阶段二使用改进后的DM-UCTransNet进行建筑损害评估,通过差异特征提取模块充分融合多尺度的建筑损害特征,嵌入空间金字塔更好捕捉小目标建筑及边缘特征,引入深度监督机制和改进损失函数加强浅层特征学习并平衡样本。实验结果表明,MGDLNet在目标数据集有较大优势,其加权F1得分相较于SegNet、UNet、DeeplabV3+、TransUNet和UCTransNet分别提高了8.6%、1.9%、5.0%、2.7%和1.4%。

关键词：建筑损害评估 UCTransNet 双阶段差异特征空间金字塔深度监督损失函数

A Novel PDF Shape Control Approach for Nonlinear Stochastic Systems

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IEEE/CAA Journal of Automatica Sinica 2022年第8期9卷 1490-1498页

作者： Lingzhi Wang guo xie Fucai Qian Jun Liu Kun Zhang Electrical Engineering Department School of AutomationXi’an University of Posts and TelecommunicationsXi’an 710121China School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China

In this work,a novel shape control approach of the probability density function(PDF)for nonlinear stochastic systems is ***,we provide the formula for the PDF shape controller without devising the control law of the ***,based on the exact analytical solution of the Fokker-PlanckKolmogorov(FPK)equation,the product function of the polynomial and the exponential polynomial is regarded as the stationary PDF of the state *** validate the performance of the proposed control approach,we compared it with the exponential polynomial method and the multi-Gaussian closure method by implementing comparative simulation *** results show that the novel PDF shape control approach is effective and *** an equal number of parameters,our method can achieve a similar or better control effect as the exponential polynomial *** comparison with the multiGaussian closure method,our method has clear advantages in PDF shape control *** all cases,the integral of squared error and the errors of first four moments of our proposed method were very small,indicating superior performance and promising good overall control effects of our *** approach presented in this study provides an alternative for PDF shape control in nonlinear stochastic systems.

关键词： Fokker-Planck-Kolmogorov(FPK)equation nonlinear control nonlinear stochastic systems probability density function(PDF)

Triggering star formation by both radiative and mechanical AGN feedback

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Research in Astronomy and Astrophysics 2013年第8期13卷 899-911页

作者： Chao Liu Zhao-Ming Gan Fu-guo xie Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences

We perform two dimensional hydrodynamic numerical simulations to study the positive active galactic nucleus （AGN） feedback which triggers, rather than suppresses, star formation. Recently, it was shown by Nayakshin et al. and Ishibashi et al. that star formation occurs when the cold interstellar medium （ISM） is squeezed by the impact of mass outflow or radiation pressure, respectively. Mass outflow is ubiquitous in this astrophysical context, and radiation pressure is also important if the AGN is luminous. For the first time in this subject, we incorporate both mass outflow feedback and radiative feedback into our model. Consequently, the ISM is shocked into shells by the AGN feedback, and these shells soon fragment into clumps and filaments because of Rayleigh-Taylor and thermal instabilities. We have two major findings：（1） the star formation rate can indeed be very large in the clumps and filaments. However, the resultant star formation rate density is too large compared with previous works, which is mainly because we ignore the fact that most of the stars that are formed would be disrupted when they move away from the galactic center. （2） Although radiation pressure feedback has a limited effect, when mass outflow feedback is also included, they reinforce each other. Specifically, in the gas-poor case, mass outflow is always the dominant contributor to feedback.

关键词： methods: numerical - accretion - shock waves - galaxies: active - galaxies: starburst

Does Diffuse Circumnuclear Gas around Sgr A^(*) Achieve Collisional Ionization Equilibrium or Remain Non-equilibrium Ionization?

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Research in Astronomy and Astrophysics 2023年第8期23卷 103-116页

作者： Shu Niu Fu-guo xie Wei Sun Li Ji Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Dark Matter and Space Astronomy Chinese Academy of SciencesNanjing 210023China

The feeding and feedback processes at the vicinity of a supermassive black hole(BH)are essential for our understanding of the connection between supermassive BH and its host *** this work,we provide a detailed investigation,both observational and theoretical,on the diffuse(~2"-20",~0.08-0.8 pc)X-ray emission around Sgr A*.Over two-decade Chandra observations are gathered to obtain highest signal-to-noise to *** find that,the line center of iron lines of the outer 8"-18"region,ε_(c)=6.65+0.02-0.03 keV,is comparable to that(ε_(c)=6.60+0.05-0.03 keV)of the inner 2"-5"*** is somewhat unexpected,since the gas temperature decreases further away from the central *** on a dynamical inflow-outflow model that considers the gas feeding by stellar winds from Wolf-Rayet stars,we calculate the X-ray spectrum based on both the conventional collisional ionization equilibrium(CIE)assumption,and the newly developed non-equilibrium ionization(NEI)*** find that,theoretically gases within~8"-10"remain in a CIE state,outside of this radius they will be in the NEI state.A comparison of the properties of~6.6 keV iron lines between CIE and NEI is ***,the NEI interpretation of outer region is supported by the Chandra line center ε_(c) measurements of this region.

关键词： X-rays diffuse background-galaxies active-Galaxy center-(galaxies:)quasars emission lines