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Neural-Network-Based Nonlinear Model Predictive Tracking Control of a Pneumatic Muscle Actuator-Driven Exoskeleton

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IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1478-1488页

作者： Yu Cao jian Huang IEEE Key Laboratory of Image Processing and Intelligent Control School of Artificial Intelligence and AutomationHuazhong University of Science and TechnologyWuhan 430074China

Pneumatic muscle actuators(PMAs)are compliant and suitable for robotic devices that have been shown to be effective in assisting patients with neurologic injuries,such as strokes,spinal cord injuries,etc.,to accomplish rehabilitation ***,because PMAs have nonlinearities,hysteresis,and uncertainties,etc.,complex mechanisms are rarely involved in the study of PMA-driven robotic *** this paper,we use nonlinear model predictive control(NMPC)and an extension of the echo state network called an echo state Gaussian process(ESGP)to design a tracking controller for a PMA-driven lower limb *** dynamics of the system include the PMA actuation and mechanism of the leg orthoses;thus,the system is represented by two nonlinear uncertain *** facilitate the design of the controller,joint angles of leg orthoses are forecasted based on the universal approximation ability of the ESGP.A gradient descent algorithm is employed to solve the optimization problem and generate the control *** stability of the closed-loop system is guaranteed when the ESGP is capable of approximating system *** and experiments are conducted to verify the approximation ability of the ESGP and achieve gait pattern training with four healthy subjects.

关键词： Echo state Gaussian process model predictive control neural network pneumatic muscle actuators-driven exoskeleton

Physics and applications of Raman distributed optical fiber sensing

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Light(Science & Applications) 2022年第6期11卷 1059-1087页

作者： jian Li Mingjiang Zhang College of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuanShanxi 030024China Key Laboratory of Advanced Transducers and Intelligent Control Systems(Ministry of Education and Shanxi Province) Taiyuan University of TechnologyTaiyuan 030024China

Raman distributed optical fiber sensing has been demonstrated to be a mature and versatile scheme that presents great flexibility and effectivity for the distributed temperature measurement of a wide range of engineering applications over other established *** past decades have witnessed its rapid development and extensive applicability ranging from scientific researches to industrial ***,there are four theoretical or technical bottlenecks in traditional Raman distributed optical fiber sensing:(ⅰ)The difference in the Raman optical attenuation,a low signal-to-noise ratio(SNR)of the system and the fixed error of the Raman demodulation equation restrict the temperature measurement accuracy of the system.{ⅱ)The sensing distance and spatial resolution cannot be reconciled.(ⅲ)There is a contradiction between the SNR and measurement time of the system.(ⅳ)Raman distributed optical fiber sensing cannot perform dual-parameter *** on the above theoretical and technical bottlenecks,advances in performance enhancements and typical applications of Raman distributed optical fiber sensing are reviewed in this *** of this optical system technology with knowledge based,that is,demodulation technology *** further the performance and accuracy of these systems.

关键词： fiber optical contradiction

茶叶不同添加方式对太平猴魁绿茶啤酒风味影响

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食品与发酵工业 2025年第1期51卷 81-89页

作者：林睿吴殿辉彭政聪谢广发陆健工业生物技术教育部重点实验室粮食发酵与食品生物制造国家工程研究中心江苏省生物活性制品加工工程技术研究中心江南大学生物工程学院江苏无锡214122 浙江省污染暴露与健康干预重点实验室浙江树人学院生物与环境工程学院浙江杭州310015

绿茶作为辅料增添啤酒风味已被众多研究者们广泛关注,但绿茶的添加方式对啤酒风味的影响鲜有研究。该文将太平猴魁以3种不同投料方式加入到啤酒的发酵中,来研究清香型绿茶投料方式对啤酒挥发性风味物质的影响。采用GC-MS对不同组啤酒的... 详细信息

绿茶作为辅料增添啤酒风味已被众多研究者们广泛关注,但绿茶的添加方式对啤酒风味的影响鲜有研究。该文将太平猴魁以3种不同投料方式加入到啤酒的发酵中,来研究清香型绿茶投料方式对啤酒挥发性风味物质的影响。采用GC-MS对不同组啤酒的风味物进行鉴定分析,通过对多种风味物质的香味活性值(odor activity values,OAV)筛选以及偏最小二乘-判别分析(partial least squares-discriminant analysis,PLS-DA),研究不同工艺下绿茶啤酒的香气组分差异和关键香气组分标记物。结果表明,不同工艺下太平猴魁绿茶啤酒的挥发性成分差异显著(P<0.05)。在太平猴魁绿茶啤酒中,以OAV≥0.1筛选出了20种香气成分,其中β-紫罗兰酮、异戊醛、β-环柠檬醛、蘑菇醇和香茅醇这5种挥发性成分来源于太平猴魁,并且在冷萃的条件下能更多保留这类风味成分,使得啤酒具有更加丰富的风味属性。根据PLS-DA模型进一步筛选得到了9种变量投影重要性值大于1的物质,其中月桂酸乙酯、乙酸苯乙酯、月桂醇、正癸醛和壬醛这类香气化合物对啤酒的清香和花香风味属性具有重要贡献,可作为区分不同工艺下太平猴魁绿茶啤酒的香气组分标记物。

关键词：绿茶啤酒太平猴魁气相色谱-质谱联用挥发性成分偏最小二乘-判别分析

Electromagnetohydrodynamic flows and mass transport in curved rectangular microchannels

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Applied Mathematics and Mechanics(English Edition) 2020年第9期41卷 1431-1446页

作者： Yongbo LIU Yongjun jian School of Mathematical Science Inner Mongolia UniversityHohhot 010021China

Curved microchannels are often encountered in lab-on-chip systems because the effective axial channel lengths of such channels are often larger than those of straight microchannels for a given per unit chip *** this paper,the effective diffusivity of a neutral solute in an oscillating electromagnetohydrodynamic(EMHD)flow through a curved rectangular microchannel is investigated *** flow is assumed as a creeping flow due to the extremely low Reynolds number in such microflow *** the theoretical analysis,we find that the effective diffusivity primarily depends on five dimensionless parameters,i.e.,the curvature ratio of the curved channel,the Schmidt number,the tidal displacement,the angular Reynolds number,and the dimensionless electric field strength *** on the obtained results,we can precisely control the mass transfer characteristics of the EMHD flow in a curved rectangular microchannel by appropriately altering the corresponding parameter values.

关键词： electromagnetohydrodynamic(EMHD)flow curved rectangular microchannel mass transfer characteristic effective diffusivity

Development of acoustic computer simulation for performance spaces: A systematic review and meta-analysis

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Building Simulation 2022年第10期15卷 1729-1745页

作者： Chao Wang jian Kang School of Architecture Tianjin UniversityTianjin 300072China UCL Institute for Environmental Design and Engineering The BartlettUniversity College London(UCL)Central House14 Upper Woburn PlaceLondon WC1H0NNUK

This article aims to review the development of acoustic computer simulation for performance spaces. The databases of Web of Science and Scopus were searched for peer-reviewed journal articles published in English between 1960 and 2021, using the keywords for “simulation”, “acoustic”, “performance space”, “measure”, and their synonyms. The inclusion criteria were as follows: (1) the searched article should be focused on the field of room acoustics (reviews were excluded);(2) a computer simulation algorithm should be used;(3) it should be clearly stated that the simulated object is a performance space;and (4) acoustic measurements should be used for comparison with the simulation. Finally, twenty studies were included. A standardised data extraction form was used to collect the modelling information, software/algorithm, indicators for comparison, and other information. The results revealed that the most used acoustic indicators were early decay time (EDT), reverberation time (T30), strength (G), and definition (D50). The accuracy of these indicators differed greatly. For non-iterative simulation, the simulation accuracies of most indicators were outside their respective just noticeable differences. Although a larger sample size was required for further validation, simulations of T30, EDT, and D50 all showed an increase in accuracy with increasing time from 1979 to 2020, except for G. In terms of frequency, the simulation was generally less accurate at lower frequencies, which occurred at T30, G, D50 and T20. However, EDT accuracy did not exhibit significant frequency sensitivity. The prediction accuracy of inter-aural cross-correlation coefficients (IACC) was even higher at low frequencies than it was at high frequencies. The average value of most indicators showed a clear systematic deviation from zero, providing hints for future algorithm improvements. Limitations and the risks of bias in this review were discussed. Finally, various types of benchmark tests were sug

关键词： acoustic simulation accuracy systematic review performance space iterative simulation

Compositional dependence of thermophysical properties in binary alkaline earth borate melts:Insights from structure in short-range and intermediate-range order

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Journal of Materials Science & Technology 2022年第36期131卷 195-203页

作者： jian Yang Il Sohn Department of Materials Science and Engineering Yonsei UniversitySeoul120749Korea State Key Laboratory of Cemented Carbide Zhuzhou 412000China

In this work,the thermal conductivity of alkaline earth borate melts was measured using hot-wire method from 1323 to 1623 K,and the thermal diffusivity was extrapolated from the thermal conductivity and heat *** compositional dependence of thermophysical properties was interpreted according to the structure in short-range and intermediate-range *** on the Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and 11B magic-angle spinning nuclear magnetic resonance(MAS-NMR)spectra,modifier cation with higher field strength prefers the formation of non-bridging oxygens(NBOs)for the charge compensation at high BO_(1.5)/MO ratios.A lower amount of covalent bond and greater isolation of large borate groups lead to a lower thermal conductivity in calcium borate melt compared with strontium and barium *** the large size of Ba^(2+)encounters difficulty in fitting around B^[4]-OB^[4]linkages inside the overcrowded large borate groups when BO_(1.5)/BaO=2.5,promoting the formation of NBOs on the edge of borate groups for the charge compensation of modifier cations and leading to the decline in the thermal *** conductivity plays a major role in regulating the thermal diffusivity at a given temperature since the compositional dependence of volumetric heat capacity is relatively weak compared with that of thermal conductivity.

关键词： Thermal conductivity Magic-angle spinning nuclear magnetic resonance(MAS-NMR) X-ray photoelectron spectroscopy(XPS) Raman spectroscopy Thermal diffusivity

Advances in communications using optical vortices

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Photonics Research 2016年第5期4卷 14-28页

作者： jian Wang Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology

An optical vortex having an isolated point singularity is associated with the spatial structure of light waves.A polarization vortex(vector beam) with a polarization singularity has spatially variant polarizations. A phase vortex with phase singularity or screw dislocation has a spiral phase front. The optical vortex has recently gained increasing interest in optical trapping, optical tweezers, laser machining, microscopy, quantum information processing, and optical communications. In this paper, we review recent advances in optical communications using optical vortices. First, basic concepts of polarization/phase vortex modulation and multiplexing in communications and key techniques of polarization/phase vortex generation and(de)multiplexing are introduced. Second, free-space and fiber optical communications using optical vortex modulation and optical vortex multiplexing are presented. Finally, key challenges and perspectives of optical communications using optical vortices are discussed. It is expected that optical vortices exploiting the space physical dimension of light waves might find more interesting applications in optical communications and interconnects.

关键词： OAM mode Advances in communications using optical vortices

State of the art in applications of machine learning in steelmaking process modeling

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2055-2075页

作者： Runhao Zhang jian Yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

With the development of automation and informatization in the steelmaking industry,the human brain gradually fails to cope with an increasing amount of data generated during the steelmaking *** learning technology provides a new method other than production experience and metallurgical principles in dealing with large amounts of *** application of machine learning in the steelmaking process has become a research hotspot in recent *** paper provides an overview of the applications of machine learning in the steelmaking process modeling involving hot metal pretreatment,primary steelmaking,secondary refining,and some other *** three most frequently used machine learning algorithms in steelmaking process modeling are the artificial neural network,support vector machine,and case-based reasoning,demonstrating proportions of 56%,14%,and 10%,*** data in the steelmaking plants are frequently ***,data processing,especially data cleaning,is crucially important to the performance of machine learning *** detection of variable importance can be used to optimize the process parameters and guide *** learning is used in hot metal pretreatment modeling mainly for endpoint S content *** predictions of the endpoints of element compositions and the process parameters are widely investigated in primary *** learning is used in secondary refining modeling mainly for ladle furnaces,Ruhrstahl–Heraeus,vacuum degassing,argon oxygen decarburization,and vacuum oxygen decarburization *** development of machine learning in the steelmaking process modeling can be realized through additional efforts in the construction of the data platform,the industrial transformation of the research achievements to the practical steelmaking process,and the improvement of the universality of the machine learning models.

关键词： machine learning steelmaking process modeling artificial neural network support vector machine case-based reasoning data processing

Practical Green’s function for the thermal stress field induced by a heat source in plane thermoelasticity

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Applied Mathematics and Mechanics(English Edition) 2020年第4期41卷 543-550页

作者： jian HUA Ming DAI State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The classical Green’s functions used in the literature for a heat source in a homogeneous elastic medium cannot lead to ?nite remote thermal stresses in the medium,so that they may not work well in practical thermal stress analyses. In this paper, we develop a practical Green’s function for a heat source disposed eccentrically into an elastic disk/cylinder subject to plane deformation. The edge of the disk/cylinder is assumed to be thermally permeable and traction-free. The full thermal stress ?eld induced by the heat source in the disk/cylinder is determined exactly and explicitly via the Cauchy integral techniques. In particular, a very simple formula is obtained to describe the hoop thermal stress on the edge of the disk/cylinder, which may be conveniently useful for analyzing the thermal stresses in microelectronic components.

关键词： heat source Green’s function thermal stress finite matrix