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robust Control Based on Fast Terminal Sliding Mode Control with Adaptive Interval Type-2 Fuzzy PId

INTErnational JOUrNAL OF FUZZY SYSTEMS 2024年第3期26卷 849-859页

作者： dong, Junjie duan, Xingguang Beijing Inst Technol Sch Mech Engn Beijing 100081 Peoples R China

This article introduces a new fault-tolerant control method based on type-2 fuzzy systems with PId fast terminal sliding mode control. By integrating the advantages of proportional-integral-derivative (PId) control with fast terminal sliding mode (FTSM) control, a novel proportional-integral-derivative fast terminal sliding mode (PId-FTSM) is developed to accelerate convergence and decrease steady-state error. To provide outstanding fault tolerant control performance and approximation of system uncertainties, a type-2 fuzzy logical switching approach law eliminates the chattering phenomenon and reduce the need of prior knowledge without affecting the system's robustness. The overall stability of the system is verified using the Lyapunov function. Finally, several experiments demonstrate that the suggested technique outperforms alternatives.

关键词： Interval type-2 fuzzy systems robust adaptive control Uncertain nonlinear systems Fault-tolerant control

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research on the effect of direct current electric field on the moisture equilibrium of oil paper

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CELLULOSE 2024年第13期31卷 8321-8333页

作者： Luo, Hao Cheng, Li Chen, Zhiling deng, Wangjun Zhao, Xuetong Yang, Lijun Chongqing Univ Sch Elect Engn State Key Lab Power Transmiss Equipment Technol Chongqing 400044 Peoples R China

Moisture is the critical factor affecting transformer oil-paper insulation's aging life and electrical strength. Currently, there is no sensing technology that directly monitors the moisture content of paper in operating transformers, and it still relies on the moisture equilibrium curves of oil-paper (MEC) to achieve indirect calculation. However, the MEC only considers the temperature effect, and the electric field effect is less studied. Therefore, research on the effect of direct current electric fields on the MEC at 80 degrees C is carried out in this work. The results show that the electric field has an inhibitory effect on moisture migration, and as the electric field strength increases, the moisture in the oil and paper will rise significantly. Compared with the MEC, the experimental result of 0 kV/mm is basically consistent, and after applying the voltage, the moisture in the paper corresponding to the same moisture in the oil increased by 5.86%, 18.61%, and 32.92% at 5 kV/mm, 15 kV/mm and 25 kV/mm on average. Moreover, the accuracy of the experimental results is further verified by macroscopic force analysis and microscopic molecular simulation calculations. This work provides a reference for correcting the MEC under the action of multi-physical fields.

关键词： Oil paper insulation Moisture equilibrium curves of oil-paper (MEC) Electric field Temperature

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Natural Gas Consumption Monitoring Based on k-NN Algorithm and Consumption Prediction Framework Based on Backpropagation Neural Network

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BUILdINGS 2024年第3期14卷 627页

作者： Hou, Yaolong Wang, Xueting Chang, Han dong, Yanan Zhang, di Wei, Chenlin Lee, Inhee Yang, Yijun Liu, Yuanzhao Zhang, Jipeng Zhengzhou Railway Vocat & Tech Coll Dept Railway Engn Zhengzhou 451460 Peoples R China Xi An Jiao Tong Univ Sch Human Settlement & Civil Engn Dept Architecture Xian 710049 Peoples R China Xi An Jiao Tong Univ Sch Comp Sci & Technol Xian 710049 Peoples R China Xi An Jiao Tong Univ Sch Humanities & Social Sci Xian 710049 Peoples R China Pusan Natl Univ Dept Architecture Busan 46241 South Korea Beijing Inst Technol Coll Comp Zhuhai 519088 Peoples R China

With increasing consumption of primary energy and deterioration of the global environment, clean energy sources with large reserves, such as natural gas, have gradually gained a higher proportion of the global energy consumption structure. Monitoring and predicting consumption data play a crucial role in reducing energy waste and improving energy supply efficiency. However, owing to factors such as high monitoring device costs, safety risks associated with device installation, and low efficiency of manual meter reading, monitoring natural gas consumption data at the household level is challenging. Moreover, there is a lack of methods for predicting natural gas consumption at the household level in residential areas, which hinders the provision of accurate services to households and gas companies. Therefore, this study proposes a gas consumption monitoring method based on the K-nearest neighbours (KNN) algorithm. Using households in a residential area in Xi'an as research subjects, the feasibility of this monitoring method was validated, achieving a model recognition accuracy of 100%, indicating the applicability of the KNN algorithm for monitoring natural gas consumption data. In addition, this study proposes a framework for a natural gas consumption prediction system based on a backpropagation (BP) neural network.

关键词： energy shortage instrument monitoring natural gas consumption KNN BP neural network

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Frequency-modulated continuous-wave laser interferometry measurement method based on cross-correlation

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MEASUrEMENT SCIENCE ANd TECHNOLOGY 2024年第8期35卷 085203-085203页

作者： Zhang, dengpan Yan, Mengchao Li, Gaochao Wang, Yongjie Li, Fang Henan Polytech Univ Sch Mech & Power Engn Jiaozuo 454000 Peoples R China Inst Semicond Chinese Acad Sci Lab Optoelect Syst Beijing 100083 Peoples R China

Frequency-modulated continuous-wave (FMCW) laser interferometry technology holds significant potential for applications in the fields of ultraprecision manufacturing and high-precision sensing. This paper proposes a novel approach among current phase demodulation methods is based on cross-correlation to address the challenge of this technology. On the basis of nonlinear correction of a distributed feedback laser, the intercepted beat frequency signal was first preprocessed with Z-score signal normalization and a smoothing filter. Subsequently, the interference beat signal was subjected to processing using a correlation method to derive the correlation function. Finally, the phase difference between adjacent beat signals was determined by pinpointing the maximum value of the cross-correlation function, enabling accurate displacement demodulation. Experimental validation was performed by constructing an FMCW laser interferometric displacement measurement system. The results indicated that the standard deviation of the displacement error for the cross-correlation method was 2.41 nm during static measurements. Compared to conventional maximum-point method, the static measurement error of the cross-correlation method has been reduced by 1.43 times. In dynamic measurements in the 500 mu m range, The measurement error of the cross-correlation method has been reduced by 6.04 times, avoiding the dynamic measurement positioning problem of conventional feature point demodulation methods and making the measurement results more accurate. This advancement holds substantial practical value in the realm of phase demodulation in laser interferometry.

关键词： frequency-modulated continuous wave cross-correlation phase demodulation laser interference distributed feedback laser

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development of a high-performance green Fe-Al_(2)O_(3)composites using Bayan Obo minerals:Enhancement effects of CeO_(2)

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Journal of rare Earths 2023年第5期41卷 747-757,I0005页

作者： Yuxin Chen Ning Wang Shengli An Changkun Cai Manyi Xie Xiwen Song School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014010China Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices Baotou 014010China Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources Ministry of EducationBaotou 014010China

With the deepening understanding for the concept of sustainable development,the utilization of minerals is no longer limited to the traditional *** this study,an environment friendly method for preparing Fe-Al_(2)O_(3)composites by using natural minerals was ***,the effects of CeO_(2)on the properties of composites were *** mechanical properties of Fe-Al_(2)O_(3)composites prepared by natural minerals are affected by the brittleness of glass *** strength and toughness of the glass phase in the composite are improved successfully by using rare earth oxides,indicating that the natural rare earths in Bayan Obo minerals have an enhanced influence on the properties of composite *** results show that the properties of glass phase can be significantly improved by addition of CeO_(2).At the optimal addition of 3 wt%CeO_(2),the composite achieves the density of 4.21 g/cm^(3),flexural strength of 401 MPa,Vickers hardness of 13.07 GPa and fracture toughness of 6.58 MPa·m^(1/2).The composite has excellent mechanical properties,which can be used in engineering as a cheap structural *** study aims at reducing waste emissions,improving energy efficiencies and avoiding waste of rare earth resources during the preparation of composite materials.

关键词： Cleaner production Natural minerals Alumina matrix composites Energy saving rare earth oxides

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Preparation of a GO@PVP@Ag SErS Substrate and Its Application in the detection of Phenanthylene in Aqueous Solution

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COATINGS 2025年第3期15卷 267-267页

作者： Liu, Junyu Li, Hansheng Cui, Wencan Sang, Shihua Guan, Liang Zhao, Chen Chengdu Univ Technol Coll Mat & Chem & Chem Engn Chengdu 610059 Peoples R China Army Logist Acad PLA Dept Basic Courses Chongqing 401331 Peoples R China

This study focuses on the preparation of a highly active surface-enhanced raman spectroscopy (SErS) substrate, where Ag nanoparticles synthesized by the Lee-Meisel method are loaded onto the surface of GO@PVP nanoparticles through classical electrostatic attraction. The substrate was characterized by SEM and XPS analysis. The SErS-active substrate was utilized for the detection of phenanthrene in aqueous solutions, achieving a detection limit of 10-8 g/L (5.6 x 10-11 mol/L). In comparison to conventional raman spectroscopy, this method exhibits a significant reduction in the detection limit and holds promise for trace polycyclic aromatic hydrocarbons (PAHs) monitoring in environmental samples.

关键词： polycyclic aromatic hydrocarbons SErS GO@PVP@Ag substrate graphene oxide

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Embedding-Alignment Fusion-Based Graph Convolution Network With Mixed Learning Strategy for 4d Medical Image reconstruction

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IEEE JOUrNAL OF BIOMEdICAL ANd HEALTH INFOrMATICS 2024年第5期28卷 2916-2929页

作者： Li, Jingshu Fu, Tianyu Song, Hong Fan, Jingfan Xiao, deqiang Lin, Yucong Gu, Ying Yang, Jian Beijing Inst Technol Sch Opt & Photon Beijing 100081 Peoples R China Beijing Inst Technol Sch Med Technol Beijing 100081 Peoples R China Beijing Inst Technol Sch Comp Sci & Technol Beijing 100081 Peoples R China Chinese Peoples Liberat Army Gen Hosp Med Ctr 1 Dept Laser Med Beijing 100853 Peoples R China Chinese Acad Med Sci Precis Laser Med Diag & Treatment Innovat Unit Beijing 100000 Peoples R China

In recent years, 4d medical image involving structural and motion information of tissue has attracted increasing attention. The key to the 4d image reconstruction is to stack the 2d slices based on matching the aligned motion states. In this study, the distribution of the 2d slices with the different motion states is modeled as a manifold graph, and the reconstruction is turned to be the graph alignment. An embedding-alignment fusion-based graph convolution network (GCN) with a mixed-learning strategy is proposed to align the graphs. Herein, the embedding and alignment processes of graphs interact with each other to realize a precise alignment with retaining the manifold distribution. The mixed strategy of self- and semi-supervised learning makes the alignment sparse to avoid the mismatching caused by outliers in the graph. In the experiment, the proposed 4d reconstruction approach is validated on the different modalities including Computed Tomography (CT), Magnetic resonance Imaging (MrI), and Ultrasound (US). We evaluate the reconstruction accuracy and compare it with those of state-of-the-art methods. The experiment results demonstrate that our approach can reconstruct a more accurate 4d image.

关键词： 4d image reconstruction graph embedding manifold alignment slice stacking

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Multimodal Physiological Analysis of Impact of Emotion on Cognitive Control in Vr

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IEEE TrANSACTIONS ON VISUALIZATION ANd COMPUTEr GrAPHICS 2024年第5期30卷 2044-2054页

作者： Li, Ming Pan, Junjun Li, Yu Gao, Yang Qin, Hong Shen, Yang Beihang Univ Beijing Peoples R China Beijing Normal Univ Beijing Peoples R China SUNY Stony Brook Stony Brook NY USA

Cognitive control is often perplexing to elucidate and can be easily influenced by emotions. Understanding the individual cognitive control level is crucial for enhancing Vr interaction and designing adaptive and self-correcting Vr/Ar applications. Emotions can reallocate processing resources and influence cognitive control performance. However, current research has primarily emphasized the impact of emotional valence on cognitive control tasks, neglecting emotional arousal. In this study, we comprehensively investigate the influence of emotions on cognitive control based on the arousal-valence model. A total of 26 participants are recruited, inducing emotions through Vr videos with high ecological validity and then performing related cognitive control tasks. Leveraging physiological data including EEG, HrV, and EdA, we employ classification techniques such as SVM, KNN, and deep learning to categorize cognitive control levels. The experiment results demonstrate that high-arousal emotions significantly enhance users' cognitive control abilities. Utilizing complementary information among multi-modal physiological signal features, we achieve an accuracy of 84.52% in distinguishing between high and low cognitive control. Additionally, time-frequency analysis results confirm the existence of neural patterns related to cognitive control, contributing to a better understanding of the neural mechanisms underlying cognitive control in Vr. Our research indicates that physiological signals measured from both the central and autonomic nervous systems can be employed for cognitive control classification, paving the way for novel approaches to improve Vr/Ar interactions.

关键词： Cognitive control emotion physiological signal deep learning

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research on High-Stability Composite Control Methods for Telescope Pointing Systems under Multiple disturbances

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SENSOrS 2024年第9期24卷 2907页

作者： Zhang, rui Zhao, Kai Fang, Sijun Fan, Wentong Hai, Hongwen Luo, Jian Li, Bohong Sun, Qicheng Song, Jie Yan, Yong Sun Yat sen Univ MOE Key Lab TianQin Mission TianQin Res Ctr Gravitat Phys Zhuhai Campus Zhuhai 519082 Peoples R China Sun Yat sen Univ Frontiers Sci Ctr TianQin Gravitat Wave Res Ctr CNSA Sch Phys & Astron Zhuhai Campus Zhuhai 519082 Peoples R China

during the operation of space gravitational wave detectors, the constellation configuration formed by three satellites gradually deviates from the ideal 60 degrees angle due to the periodic variations in orbits. To ensure the stability of inter-satellite laser links, active compensation of the breathing angle variation within the constellation plane is achieved by rotating the optical subassembly through the telescope pointing mechanism. This paper proposes a high-performance robust composite control method designed to enhance the robust stability, disturbance rejection, and tracking performance of the telescope pointing system. Specifically, based on the dynamic model of the telescope pointing mechanism and the disturbance noise model, an H-infinity controller has been designed to ensure system stability and disturbance rejection capabilities. Meanwhile, employing the method of an H-infinity norm optimized disturbance observer (HOdOB) enhances the nonlinear friction rejection ability of the telescope pointing system. The simulation results indicate that, compared to the traditional disturbance observer (dOB) design, utilizing the HOdOB method can enhance the tracking accuracy and pointing stability of the telescope pointing system by an order of magnitude. Furthermore, the proposed composite control method improves the overall system performance, ensuring that the stability of the telescope pointing system meets the 10 nrad/Hz(1/2) @0.1 mHz similar to 1 Hz requirement specified for the TianQin mission.

关键词： space gravitational wave breathing angle variation telescope pointing mechanism H-infinity controller HOdOB pointing stability

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Heterotrophic Nitrification-Aerobic denitrification by Bacillus sp. L2: Mechanism of denitrification and Strain Immobilization

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WATEr 2024年第3期16卷 416页

作者： Li, Qiang He, Yuehui Wang, Boyan Weng, Nanhai Zhang, Lei Wang, Kaichun Tian, Fengrong Lyu, Mingsheng Wang, Shujun Jiangsu Ocean Univ Jiangsu Key Lab Marine Bioresources & Environm Jiangsu Key Lab Marine Biotechnol Lianyungang 222005 Peoples R China Jiangsu Ocean Univ Coinnovat Ctr Jiangsu Marine Bioind Technol Lianyungang 222005 Peoples R China Zhonglan Lianhai Design & Res Inst Co Ltd Lianyungang 222004 Peoples R China

The biological denitrification of low-C/N wastewater is a great challenge in treatment plants due to the lack of microorganisms with heterotrophic nitrification-aerobic denitrification (HN-Ad) abilities. In this study, Bacillus sp. L2 was isolated from aeration tank water samples using a nitrification medium and screened for its ability to perform HN-Ad in low-C/N wastewater. The strain showed a maximum NH4+-N removal rate of 98.37% under low-C/N conditions. In the presence of a mixed N source, strain L2 was capable of completely removing NH4+-N within 24 h. Furthermore, optimal nitrogen removal conditions for strain L2 were found to be C/N = 9, pH = 9, and sodium acetate as the C source. Under optimal conditions, the strain was able to maintain a high NH4+-N removal rate under 0-3% salinity and an NH4+-N concentration of 200 mg/L or less. The denitrification pathways of strain L2 were NH4+-> NH2OH -> NO2-(<-> NO3-)-> NO -> N2O -> N-2 and NH4+-> NH2OH -> NO -> N2O -> N-2. Furthermore, semi-continuous wastewater treatment was conducted using immobilized technology, which resulted in more than 82% NH4+-N removal after three cycles of reuse. This study demonstrates the great potential of Bacillus sp. L2 in wastewater treatment applications.

关键词： nitrogen removal wastewater heterotrophic nitrification-aerobic denitrification immobilization denitrification pathways

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