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Mechanism-learning coupling paradigms for parameter inversion and simulation in earth surface systems

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Science China Earth Sciences 2023年第3期66卷 568-582页

作者： Huanfeng shen Liangpei zhang School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China Key Laboratory of Geographic Information System(Ministry of Education) Wuhan UniversityWuhan 430079China State Key Laboratory of Information Engineering Survey Mapping and Remote SensingWuhan UniversityWuhan 430079China

Building the physics-driven mechanism model has always been the core scientific paradigm for parameter estimation in Earth surface systems,and developing the data-driven machine learning model is a crucial way for paradigm transformation in geoscience *** coupling of mechanism and learning models can realize the combination of“rationalism”and“empiricism”,which is one of the most concerned research *** this paper,for remote sensing inversion and dynamic simulation,we deeply analyze the internal bottleneck and complementarity of mechanism and learning models and build a coupling paradigm framework with mechanism-learning cascading model,learning-embedded mechanism model,and mechanism-infused learning *** systematically summarize ten specific coupling methods,including preprocessing and initialization,intermediate variable transfer,post-refinement processing,model substitution,model adjustment,model solution,input variable constraints,objective function constraints,model structure constraints,hybrid,etc.,and analyze the main existing problems and future *** research aims to provide a new perspective for in-depth understanding and application of the mechanism-learning coupling model and provide theoretical and technical support for improving the inversion and simulation capabilities of parameters in Earth surface systems and serving the development of Earth system science.

关键词： Mechanism model Machine learning Model coupling Remote sensing inversion Numerical simulation

Adaptive variable structure control for large-scale time-delayed systems with unknown nonlinear dead-zone

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Journal of Systems Engineering and Electronics 2007年第4期18卷 865-870页

作者： shen Qikun zhang Tianping Dept. of Computer Coll. of Information Engineering Yangzhou Univ. Yangzhou 225009 P. R. China

The problem of adaptive fuzzy control for a class of large-scale, time-delayed systems with unknown nonlinear dead-zone is discussed here. Based on the principle of variable structure control, a design scheme of adaptive, decentralized, variable structure control is proposed. The approach removes the conditions that the dead-zone slopes and boundaries are equal and symmetric, respectively. In addition, it does not require that the assumptions that all parameters of the nonlinear dead-zone model and the lumped uncertainty are known constants. The adaptive compensation terms of the approximation errors axe adopted to minimize the influence of modeling errors and parameter estimation errors. By theoretical analysis, the closed-loop control system is proved to be semiglobally uniformly ultimately bounded, with tracking errors converging to zero. Simulation results demonstrate the effectiveness of the approach.

关键词： nonlinear dead-zone decentralized control adaptive control variable structure control

Colorimetric characterization of imaging device by total color difference minimization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 1041-1045页

作者： MOU Tong-sheng shen Hui-liang State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China Department of lnformation and Electronic Engineering Zhejiang University Hangzhou 310027 China

Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not mean the mini-mization of perceptual error. A novel method for colorimetric characterization of imaging device based on the minimization of total color difference is proposed. The method builds the transform between RGB space and CIELAB space directly using the downhill simplex algorithm. Experimental results showed that the proposed method performs better than traditional least-square (LS) and total-least-square (TLS) methods, especially for colors with low luminance values.

关键词： Colorimetric characterization Color difference Imaging device

3D HYBRID DEPTH MIGRATION AND FOUR-WAY SPLITTING SCHEMES

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Journal of Computational Mathematics 2006年第4期24卷 463-474页

作者： Wen-sheng zhang Guan-quan zhang LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The alternately directional implicit （ADI） scheme is usually used in 3D depth migration. It splits the 3D square-root operator along crossline and inline directions alternately. In this paper, based on the ideal of data line, the four-way splitting schemes and their splitting errors for the finite-difference （FD） method and the hybrid method are investigated. The wavefield extrapolation of four-way splitting scheme is accomplished on a data line and is stable unconditionally. Numerical analysis of splitting errors show that the two-way FD migration have visible numerical anisotropic errors, and that four-way FD migration has much less splitting errors than two-way FD migration has. For the hybrid method, the differences of numerical anisotropic errors between two-way scheme and four-way scheme are small in the case of lower lateral velocity variations. The schemes presented in this paper can be used in 3D post-stack or prestack depth migration. Two numerical calculations of 3D depth migration are completed. One is the four-way FD and hybrid 3D post-stack depth migration for an impulse response, which shows that the anisotropic errors can be eliminated effectively in the cases of constant and variable velocity variations. The other is the 3D shot-profile prestack depth migration for SEG/EAEG benchmark model with two-way hybrid splitting scheme, which presents good imaging results. The Message Passing Interface （MPI） programme based on shot number is adopted.

关键词： 3D depth migration Multiway splitting Data line Wavefield computation Finite-difference Hybrid method.

ASICla contributes to the symptom of pain in a ra＇ model of chronic prostatitis

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Asian Journal of Andrology 2018年第3期20卷 300-305页

作者： Song Fan Zong-Yao Hao Li zhang Jun Zhou Yi-Fei zhang shen Tai Xian-sheng zhang Chao-Zhao Liang Department of Urology Institute of Urology Anhui Medical University Hefei 230022 China The First Affiliated Hospital of Anhui Medical University Hefei 230022 China

This study aims to validate our hypothesis that acid-sensing ion channels （ASICs） may contribute to the symptom of pain in patients with chronic prostatitis （CP）. We first established a CP rat model, then isolated the L5-S2 spinal dorsal horn neurons for further studies. ASICla was knocked down and its effects on the expression of neurogenic inflammation-related factors in the dorsal horn neurons of rat spinal cord were evaluated. The effect of ASICla on the Ca2＋ ion concentration in the dorsal horn neurons of rat spinal cord was measured by the intracellular calcium （[Ca~＊]i） intensity. The effect of ASICla on the p38/mitogen-activated protein kinase （MAPK） signaling pathway was also determined. ASICla was significantly upregulated in the CP rat model as compared with control rats. Acid-induced ASICla expression increased [Ca2＋]i intensity in the dorsal horn neurons of rat spinal cord. ASICla also increased the levels of neurogenic inflammation-related factors and p-p38 expression in the acid-treated dorsal horn neurons. Notably, ASICla knockdown significantly decreased the expression of pro-inflammatory cytokines. Furthermore, the levels of p-p38 and pro-inflammatory cytokines in acid-treated dorsal horn neurons were significantly decreased in the presence of PcTx-1, BAPTA-AM, or SB203580. Our results showed that ASIC1a may contribute to the symptom of pain in patients with CP, at least partially, by regulating the p38/MAPK signaling pathway.

关键词： ASICla chronic prostatitis pain symptom

Tissue Extracts From Infarcted Myocardium of Rats in Promoting the Differentiation of Bone Marrow Stromal Cells Into Cardiomyocyte-like Cells

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Biomedical and Environmental Sciences 2008年第2期21卷 110-117页

作者： XIAO-NING LIU Oi YIN HAO zhang HONG zhang shen-JUN ZHU YING-Jie WEI sheng-SHOU HU Key Laboratory of Cardiovascular Regenerative Medicine Ministry of Health and Department of Cardiovascular Surgery Cardiovascular Institute of Fuwai Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China Department of Thoracicand Cardiovascular Surgery FirstAffiliated Hospital Wenzhou Medical College Wenzhou 325000 Zhejiang China

Objective To investigate whether cardiac tissue extracts from rats could mimic the cardiac microenvironment and act as a natural inducer in promoting the differentiation of bone marrow stromal cells （BMSCs） into cardiomyocytes. Methods Three kinds of tissue extract or cell lysate [infarcted myocardial tissue extract （IMTE）, normal myocardial tissue extract （NMTE） and cultured neonatal myocardial lysate （NML）] were employed to induce BMSCs into cardiomyocyte-like cells. The cells were harvested at each time point for reverse transcription-polymerase chain reaction （RT-PCR） detection, immunocytochemical analysis, and transmission electron microscopy. Results After a 7-day induction, BMSCs were enlarged and polygonal in morphology. Myofilaments, striated sarcomeres, Z-lines, and more mitochondia were observed under transmission electron microscope. Elevated expression levels of cardiac-specific genes and proteins were also confirmed by RT-PCR and immunocytochemistry. Moreover, IMTE showed a greater capacity of differentiating BMSCs into cardiomyocyte-like cells. Conclusions Cardiac tissue extracts, especially IMTE, can effectively differentiate BMSCs into cardiomyocyte-like cells.

关键词： Bone marrow stromal cells Cell differentiation Cardiac tissue extracts Myocardial infarction

Optimal comfortability control of hybrid electric powertrains in acceleration mode

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Science China(Information Sciences) 2021年第7期64卷 25-36页

作者： Bo zhang Yahui zhang Jiangyan zhang Tielong shen Department of Engineering and Applied Sciences Sophia University College of Mechanical and Electronic Engineering Dalian Minzu University

This paper presents a control design approach for optimizing the comfortability of hybrid electric powertrains in acceleration mode. A parallel hybrid electric vehicle powertrain system with two motors and a single turbo-charged engine is considered. In acceleration mode, it is assumed that the desired acceleration rate cannot be satisfied by using the electrical motor individually. The first challenge is managing the combustion engine to assist power generation and power split such that the system satisfies comfortability,and the second challenge is modeling the comfortability(e.g., analytically describing the human feeling).This paper exploits a black-box module typically used in the automotive industry to quantitatively evaluate comfortability. A genetic algorithm is applied to find the optimum power split and gear schedule that can improve the comfortability evaluated by the module in acceleration mode. The simulation results conducted on a simulator with a practical background demonstrate the significance of the proposed design approach.

关键词： ride comfortability black-box module hybrid electric vehicles (HEVs) genetic algorithm (GA) acceleration mode

Study of the thermal influence on the dynamic characteristics of the motorized spindle system

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Advances in Manufacturing 2016年第4期4卷 355-362页

作者： Song-sheng Li Yuan shen Qiang He School of Mechatronic Engineering and Automation Shanghai Key Laboratory of Intelligent Manufacturing andRobotics Shanghai University Shanghai 200072People's Republic of China School of Mechanical Engineering Anyang Institute ofTechnology Anyang 455000 HenanPeople's Republic of China

The severe internal heat generation of the motorized spindle system causes uneven temperature dis- tribution, and will affect the vibration characteristics of the system. Based on the thermal analysis about the motorized spindle by finite element method （FEM）, the thermal deformations of the spindle system are calculated by the thermal structure coupling simulation, and the thermal deformations of the rotor and the bearing units are extracted to analyze the bearing stiffness changes so that the modal characteristics of the rotor can be simulated in different thermal state conditions. And then the rotor thermal deformation experiment and the modal experiment of spindle by exciting with hammer are performed. The result shows that the thermal state of the motorized spindle system has a significant influence on the natural frequency of the rotor, which can be carefully treated when a spindle system is designed.

关键词： Motorized spindle Thermal characteristic Thermal-structure coupling Modal analysis Spindlesystem

Understanding of performance degradation of LiNi0.80Co0.10Mn0.10O2 cathode material operating at high potentials

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Journal of Energy Chemistry 2020年第2期29卷 135-141页

作者： sheng Szhang Electrochemistry Branch FCDD-RLS-DCSensors and Electron Devices DirectorateU.S.Army Research LaboratoryAdelphiMD 20783-1138USA

Inferior cycling stability, poor safety, and gas generation are long lasting problems of Ni-rich Li Ni0.80 Co0.10 Mn0.10 O2(NCM811) cathode material. Although much effort has been made, mechanisms for the above problems are poorly understood. Studying the cycling and float-charging characteristics of Li/NCM811 cells in high voltage conditions(4.5 V and 4.7 V, respectively), in this work we find that nearly all known problems with NCM811 material can be attributed to the oxidation of lattice oxygen occurring in the capacity region corresponding to H2 → H3 phase transition. While contributing to overall capacity,the oxidation of lattice oxygen results in a loss of oxygen through oxygen evolution and relative reactions between active oxygen evolution intermediates and electrolyte solvents. It is the loss of oxygen that results in irreversible layered-spinel-rocksalt phase transition, secondary particle cracking, and performance degradation. The conclusions of this work suggest that the priority for further research on NCM811 material should give to the suppression of oxygen evolution, followed by the use of the anti-oxygen electrolyte being chemically stable against the active oxygen evolution intermediates.

关键词： Ni-rich cathode Lattice oxygen Phase transition Oxygen evolution Performance degradation