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Chinese Journal of Electronics 2024年第3期33卷 814-822页

作者： Junqi LIU Tao WEN guo xie Yuan CAO Clive Roberts Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology The School of Electronic and Information Engineering Beijing Jiaotong University Birmingham Centre for Railway Research and Education University of Birmingham

The fault diagnosis of railway point machines(RPMs) has attracted the attention of engineers and researchers.Seldom have studies considered diverse noises along the track.To fulfill this aspect,a multi-time-scale variational mode decomposition(MTSVMD) is proposed in this paper to realize the accurate and robust fault diagnosis of RPMs under multiple noises.MTSVMD decomposes condition monitoring signals after coarse-grained processing in varying degrees.In this manner,the information contained in the signal components at multiple time scales can construct a more abundant feature space than at a single scale.In the experimental validation,a random position,random type,random number,and random length(4R) noise-adding algorithm helps to verify the robustness of the approach.The adequate experimental results demoristrate the superiority of the proposed MTSVMD-based fault diagnosis.

关键词： Fault diagnosis Condition monitoring Noise Signal processing algorithms Aerospace electronics Rail transportation Robustness

Vibration-Based Fault Diagnosis for Railway Point Machines Using VMD and Multiscale Fluctuation-Based Dispersion Entropy

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Chinese Journal of Electronics 2024年第3期33卷 803-813页

作者： Yongkui SUN Yuan CAO Peng LI guo xie Tao WEN Shuai SU National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University School of Electronic and Information Engineering Beijing Jiaotong University Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University

As one of the most important railway signaling equipment,railway point machines undertake the major task of ensuring train operation safety.Thus fault diagnosis for railway point machines becomes a hot topic.Considering the advantage of the anti-interference characteristics of vibration signals,this paper proposes an novel intelligent fault diagnosis method for railway point machines based on vibration signals.A feature extraction method combining variational mode decomposition(VMD) and multiscale fluctuation-based dispersion entropy is developed,which is verified a more effective tool for feature selection.Then,a two-stage feature selection method based on Fisher discrimination and ReliefF is proposed,which is validated more powerful than single feature selection methods.Finally,support vector machine is utilized for fault diagnosis.Experiment comparisons show that the proposed method performs best.The diagnosis accuracies of normal-reverse and reverse-normal switching processes reach 100% and 96.57% respectively.Especially,it is a try to use new means for fault diagnosis on railway point machines,which can also provide references for similar fields.

关键词： Fault diagnosis Vibrations Support vector machines Diversity reception Switches Feature extraction Rail transportation

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 presented.First,we provide the formula for the PDF shape controller without devising the control law of the controller.Then,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 response.To 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 experiments.The results show that the novel PDF shape control approach is effective and feasible.Using an equal number of parameters,our method can achieve a similar or better control effect as the exponential polynomial method.By comparison with the multiGaussian closure method,our method has clear advantages in PDF shape control performance.For 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 method.The 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)

Modified multi-scale symbolic dynamic entropy and fuzzy broad learning-based fast fault diagnosis of railway point machines

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Transportation Safety and Environment 2023年第4期5卷 1-7页

作者： Junqi Liu Tao Wen guo xie Yuan Cao Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an University of TechnologyXi’an 710048ShaanxiChina School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China National Engineering Research Center of Rail Transportation Operation Control System Beijing Jiaotong UniversityBeijing 100044China

Railway point machine(RPM)condition monitoring has attracted engineers’attention for safe train operation and accident prevention.To realize the fast and accurate fault diagnosis of RPMs,this paper proposes a method based on entropy measurement and broad learning system(BLS).Firstly,the modified multi-scale symbolic dynamic entropy(MMSDE)module extracts dynamic characteristics from the collected acoustic signals as entropy features.Then,the fuzzy BLS takes the above entropy features as input to complete model training.Fuzzy BLS introduces the Takagi-Sug eno fuzzy system into BLS,which improves the model’s classification performance while considering computational speed.Experimental results indicate that the proposed method significantly reduces the running time while maintaining high accuracy.

关键词： railway point machine(RPM) fault diagnosis modified multi-scale symbolic dynamic entropy(MMSDE) fuzzy board learning system(BLS)

Rethinking attribute localization for zero-shot learning

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Science China(Information Sciences) 2024年第7期67卷 184-196页

作者： Shuhuang CHEN Shiming CHEN guo-Sen xie Xiangbo SHU Xinge YOU Xuelong LI School of Electronic Information and Communication Huazhong University of Science and Technology School of Computer Science and Engineering Nanjing University of Science and Technology School of Artificial Intelligence Optics and Electronics Northwestern Polytechnical University

Recent advancements in attribute localization have showcased its potential in discovering the intrinsic semantic knowledge for visual feature representations, thereby facilitating significant visual-semantic interactions essential for zero-shot learning(ZSL). However, the majority of existing attribute localization methods heavily rely on classification constraints, resulting in accurate localization of only a few attributes while neglecting the rest important attributes associated with other classes. This limitation hinders the discovery of the intrinsic semantic relationships between attributes and visual features across all classes.To address this problem, we propose a novel attribute localization refinement(ALR) module designed to enhance the model's ability to accurately localize all attributes. Essentially, we enhance weak discriminant attributes by grouping them and introduce weighted attribute regression to standardize the mapping values of semantic attributes. This module can be flexibly combined with existing attribute localization methods.Our experiments show that when combined with the ALR module, the localization errors in existing methods are corrected, and state-of-the-art classification performance is achieved.

关键词： zero-shot learning attention mechanism attribute localization image classification

1963年伯明翰运动与肯尼迪政府民权法案的出台

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史学集刊 2024年第4期 126-144页

作者：谢国荣华东师范大学历史学系上海200241

自1960年入座运动开展以来,美国民权运动在直接行动阶段取得了一系列丰硕成果,但这种非暴力斗争在奥尔巴尼运动中却遭到重大挫败。为避免重蹈覆辙并防止民权运动进入“冷却期”,马丁·路德·金和南方基督教领导大会周密筹划,特意选择在... 详细信息

自1960年入座运动开展以来,美国民权运动在直接行动阶段取得了一系列丰硕成果,但这种非暴力斗争在奥尔巴尼运动中却遭到重大挫败。为避免重蹈覆辙并防止民权运动进入“冷却期”,马丁·路德·金和南方基督教领导大会周密筹划,特意选择在种族隔离十分严重且容易激起种族暴力的伯明翰市开展民权运动。金不仅公开发表《伯明翰狱中来信》,而且把黑人学童带到民权运动的现场。伯明翰运动促使美国民权运动走向激进化。伯明翰警察局长康纳下令用高压水龙头和警犬对付非暴力的示威民众,甚至连黑人学童亦不例外。这一幕给美国的国家形象、声誉和外交造成巨大伤害,威胁到美国在冷战中对20世纪60年代大量新兴的非洲独立国家的争夺。伯明翰运动唤起了美国社会具有同情心和正义感的白人民众的支持,而且迫使肯尼迪政府从冷战成败的高度出台了民权法案。美国民权运动由此进入民权立法的黄金时代。

关键词：非暴力斗争伯明翰运动《伯明翰狱中来信》冷战民权法案

纳米氧化锌对钙钛矿薄膜本征性能和光谱性能的影响研究

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光谱学与光谱分析 2024年第5期44卷 1482-1486页

作者：于嫚谢国鑫赵肖娟李兆西安航空学院材料工程学院陕西西安710077

有机-无机杂化钙钛矿太阳能电池因其优异的光电特性、低廉的制备成本、高效的转换效率等优越特性,成为光伏领域的研究热点。电子传输层作为钙钛矿电池的核心层,主要起到提取和传输光生载流子的作用,且能够作为空穴阻挡层,抑制钙钛矿活... 详细信息

有机-无机杂化钙钛矿太阳能电池因其优异的光电特性、低廉的制备成本、高效的转换效率等优越特性,成为光伏领域的研究热点。电子传输层作为钙钛矿电池的核心层,主要起到提取和传输光生载流子的作用,且能够作为空穴阻挡层,抑制钙钛矿活性层中电荷复合,所以优异性能的电子传输层对钙钛矿太阳能电池的发展至关重要。可目前钙钛矿光伏器件常用的刚性电子传输层(介孔层或致密层)均需要高温烧结,这限制了其在柔性钙钛矿器件方面的应用。因此,开发一种可应用于钙钛矿光伏领域的柔性电子传输层成为当前亟待解决的问题之一。纳米ZnO具有合适的能级和较高的电子迁移率,且可以通过低温制备,被广泛应用在光伏器件中作为电子传输层。因此,通过旋涂法和静电纺丝法分别制备了刚性纳米ZnO和柔性纳米ZnO电子传输层,确定了静电纺丝法制备柔性纳米ZnO的最佳制备工艺。利用扫描电子显微镜、X射线衍射仪、紫外可见分光光度计和稳态/瞬态荧光光谱系统研究了刚性和柔性纳米ZnO对钙钛矿薄膜形貌、结构和光谱性能的影响。结果表明,钙钛矿薄膜的形貌对基底纳米ZnO的形貌依赖性很强。而基于刚性和柔性纳米ZnO的钙钛矿薄膜几乎呈现相同的结构和光谱吸收范围,荧光发射峰均在770 nm附近,且柔性纳米ZnO的荧光猝灭效率为82%,几乎和刚性纳米ZnO的荧光猝灭效率(85%)相媲美。进一步,根据瞬态荧光动力学数据计算获得刚性和柔性纳米ZnO的界面电荷分离效率分别为61%和41%,这表明通过静电纺丝法制备的柔性纳米ZnO具备一定的界面电荷分离能力,有望成为新型的柔性电子传输层。这对柔性基底钙钛矿太阳能电池的设计具有重要参考价值,对促进钙钛矿光伏应用具有现实意义。

关键词：纳米氧化锌钙钛矿薄膜形貌结构光谱性能

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

旅游宣传材料多模态语步分析的历史演进与未来趋势

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梧州学院学报 2024年第3期34卷 12-20页

作者：谢果桂林旅游学院外国语学院广西桂林541006

深入分析了多模态语步分析在旅游宣传材料中的应用,涵盖其历史演变、当前实践和未来发展趋势。研究结果表明:该领域已从最初的单一模态文字文本分析,发展到现今综合考量多种模态相互作用的复杂分析。通过对“中国·西安”旅游宣传视频... 详细信息

深入分析了多模态语步分析在旅游宣传材料中的应用,涵盖其历史演变、当前实践和未来发展趋势。研究结果表明:该领域已从最初的单一模态文字文本分析,发展到现今综合考量多种模态相互作用的复杂分析。通过对“中国·西安”旅游宣传视频案例的分析,揭示了多模态分析在深入理解和影响旅游宣传材料设计方面的重要作用。此外,探讨了在数字技术、人工智能应用及跨文化交流方面,多模态分析所面临的挑战和新机遇。尽管在案例分析的深度和广度上有所限制,但该研究可为全面理解旅游宣传材料中的多模态语步分析提供参考,并对未来的研究方向提出了建议。

关键词：多模态语步分析旅游宣传材料符号系统

Performance evaluation of a bubble generator and a bubble separator designed for the gas removal system of a small thorium molten salt reactor

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1250-1259页

作者： Licheng Sun Liang Zhao Min Du Zhengyu Mo Jiguo Tang guo xie State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource&HydropowerSichuan UniversityChengdu 610065China

In the present study, a bubble generator and a bubble separator were designed and evaluated for an independent off-gas removal system of a small thorium molten salt reactor(TMSR) with reference to the design of the Oak Ridge National Laboratory(ONRL). The bubble generator employed a Venturi tube as its main body owing to its simplicity and highly reliable structure. A centrifugal separator was used as the bubble separator, taking advantage of the kinetic energy of fluid to create a centrifugal force to separate gas bubbles from the mixture flow. Both the bubble generator and the separator were demonstrated to have good potential to meet the performance requirements of an off-gas removal system for a small TMSR. With water and air as the working fluids, for the final designs of the two key pieces of equipment, a liquid flow rate exceeding 15 m3·h-1 can essentially make their performance meet the requirements of the off-gas removal system in terms of the average size of the generated bubbles and gas separation efficiency.

关键词： Bubble generator Venturi Bubble separator Off-gas removal TMSR