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THE METRIC GENERALIZED INVERSE AND ITS SINGLE-VALUE SELECTION IN THE PRICING OF CONTINGENT CLAIMS IN AN INCOMPLETE FINANCIAL MARKET
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作者 Zi WANG Xiaoling WANG Yuwen WANG 《Acta Mathematica Scientia》 SCIE CSCD 2022年第4期1681-1689,共9页
This article continues to study the research suggestions in depth made by M.Z.Nashed and G.F.Votruba in the journal"Bull.Amer.Math.Soc."in 1974.Concerned with the pricing of non-reachable"contingent cla... This article continues to study the research suggestions in depth made by M.Z.Nashed and G.F.Votruba in the journal"Bull.Amer.Math.Soc."in 1974.Concerned with the pricing of non-reachable"contingent claims"in an incomplete financial market,when constructing a specific bounded linear operator A:l_(1)^(n)→l_(2) from a non-reflexive Banach space l_(1)^(n) to a Hilbert space l_(2),the problem of non-reachable"contingent claims"pricing is reduced to researching the(single-valued)selection of the(set-valued)metric generalized inverse A■ of the operator A.In this paper,by using the Banach space structure theory and the generalized inverse method of operators,we obtain a bounded linear single-valued selection A^(σ)=A+of A■. 展开更多
关键词 incomplete financial market bounded linear operator metric generalized inverse single-value selection Moore-Penrose generalized inverse
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Third Hankel Determinant for the Inverse of Starlike and Convex Functions 被引量:2
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作者 Guo Dong Ao En +2 位作者 Tang Huo Xiong Liang-peng Ji You-qing 《Communications in Mathematical Research》 CSCD 2019年第4期354-358,共5页
Denote S to be the class of functions which are analytic,normalized and univalent in the open unit disk U={z:|z|<1}.The important subclasses of S are the class of starlike and convex functions,which we denote by S ... Denote S to be the class of functions which are analytic,normalized and univalent in the open unit disk U={z:|z|<1}.The important subclasses of S are the class of starlike and convex functions,which we denote by S and C.In this paper,we obtain the third Hankel determinant for the inverse of functions f(z)=z+∞Σn=2 anz^n belonging to S^*and C. 展开更多
关键词 analytic function THIRD HANKEL DETERMINANT inverse of STARLIKE function inverse of convex function
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THE INTEGRAL OF THE INVERSE FUNCTION OF φ FOR AN ANALYTICAL SOLUTION TO THE COMPRESSION OF A THIN WORKPIECE 被引量:2
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作者 Zhao, Dewen Northeast University of Technology, Shenyang 110006, China Fang, Youkang Institute fur Angewandte Mathematik Albert-Ludwigs Universitat, Hemann-Henter Str 10 7800 Freihurg.1. Br. BRD, Germany 《中国有色金属学会会刊:英文版》 CSCD 1993年第1期42-44,共3页
An analytical solution of the unit pressure on a thin workpiece under compression has been obtained by using the inverse function of φ to the integral integral from 0 to x φ dx. Its result is basically the same as t... An analytical solution of the unit pressure on a thin workpiece under compression has been obtained by using the inverse function of φ to the integral integral from 0 to x φ dx. Its result is basically the same as the prevailing numerical formula integral from 0 to x φdx=∑√<sub>1</sub>-Δx<sub>1</sub>. However, the new integral is simpler and more convenient to use. 展开更多
关键词 SLIP line field THIN WORKPIECE inverse function analytical solution
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Repetitive PD control strategy with inverse transfer function compensation for CVCF inverter 被引量:2
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作者 ShanxuDUAN 《控制理论与应用(英文版)》 EI 2004年第2期121-125,共5页
A novel repetitive control strategy for the output waveform of single-phase CVCF inverters is presented. In this scheme, the inverse transfer function of inverter is used as a compensator to obtain stable and satisfy ... A novel repetitive control strategy for the output waveform of single-phase CVCF inverters is presented. In this scheme, the inverse transfer function of inverter is used as a compensator to obtain stable and satisfy harmonic rejection. Besides, PD controller is adopted to improve transient performance. Simulation and experimental results, which are gotten from a DSP-based 400Hz, 5.5KW inverter, indicate that the proposed control scheme can achieve not only low THD during steady-state operation but also fast transient response during load step change. 展开更多
关键词 INVERTER inverse transfer function Repetitive control PD control
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Non-concomitant cortical structural and functional alterations in sensorimotor areas following incomplete spinal cord injury 被引量:2
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作者 Yu Pan Wei-bei Dou +9 位作者 Yue-heng Wang Hui-wen Luo Yun-xiang Ge Shu-yu Yan Quan Xu Yuan-yuan Tu Yan-qing Xiao Qiong Wu Zhuo-zhao Zheng Hong-liang Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第12期2059-2066,共8页
Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury(SCI). The correlation between brain anatomical changes and fun... Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury(SCI). The correlation between brain anatomical changes and functional reorganization after SCI is unclear. This study aimed to explore whether alterations of cortical structure and network function are concomitant in sensorimotor areas after incomplete SCI. Eighteen patients with incomplete SCI(mean age 40.94 ± 14.10 years old; male:female, 7:11) and 18 healthy subjects(37.33 ± 11.79 years old; male:female, 7:11) were studied by resting state functional magnetic resonance imaging. Gray matter volume(GMV) and functional connectivity were used to evaluate cortical structure and network function, respectively. There was no significant alteration of GMV in sensorimotor areas in patients with incomplete SCI compared with healthy subjects. Intra-hemispheric functional connectivity between left primary somatosensory cortex(BA1) and left primary motor cortex(BA4), and left BA1 and left somatosensory association cortex(BA5) was decreased, as well as inter-hemispheric functional connectivity between left BA1 and right BA4, left BA1 and right BA5, and left BA4 and right BA5 in patients with SCI. Functional connectivity between both BA4 areas was also decreased. The decreased functional connectivity between the left BA1 and the right BA4 positively correlated with American Spinal Injury Association sensory score in SCI patients. The results indicate that alterations of cortical anatomical structure and network functional connectivity in sensorimotor areas were non-concomitant in patients with incomplete SCI, indicating the network functional changes in sensorimotor areas may not be dependent on anatomic structure. The strength of functional connectivity within sensorimotor areas could serve as a potential imaging biomarker for assessment and prediction of sensory function in patients with incomplete SCI. This trial was registered with the Chinese Clinical Trial Registry(registration number: Chi CTR-ROC-17013566). 展开更多
关键词 nerve regeneration incomplete spinal cord injury gray matter volume functional connectivity sensorimotor areas functionalmagnetic resonance imaging brain plasticity non-concomitant anatomical structure network imaging biomarker neural regeneration
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Multi-criteria classification approach with polynomial aggregation function and incomplete certain information 被引量:1
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作者 Wang Jianqiang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第3期546-550,共5页
The relationship between the importance of criterion and the criterion aggregation function is discussed, criterion's weight and combinational weights between some criteria are defined, and a multi-criteria classific... The relationship between the importance of criterion and the criterion aggregation function is discussed, criterion's weight and combinational weights between some criteria are defined, and a multi-criteria classification method with incomplete certain information and polynomial aggregation function is proposed. First, linear programming is constructed by classification to reference alternative set (assignment examples) and incomplete certain information on criterion's weights. Then the coefficient of the polynomial aggregation function and thresholds of categories are gained by solving the linear programming. And the consistency index of alternatives is obtained, the classification of the alternatives is achieved. The certain criteria's values of categories and uncertain criteria's values of categories are discussed in the method. Finally, an example shows the feasibility and availability of this method. 展开更多
关键词 multi-criteria decision-making incomplete certain information polynomial function classification.
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Crustal and uppermost mantle structure of the northeastern Qinghai-Xizang Plateau from joint inversion of surface wave dispersions and receiver functions with P velocity constraints
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作者 Pei Zhang Xiaodong Song +2 位作者 Jiangtao Li Xingchen Wang Xuezhen Zhang 《Earthquake Science》 2024年第2期93-106,共14页
Lithospheric structure beneath the northeastern Qinghai-Xizang Plateau is of vital significance for studying the geodynamic processes of crustal thickening and expansion of the Qinghai-Xizang Plateau. We conducted a j... Lithospheric structure beneath the northeastern Qinghai-Xizang Plateau is of vital significance for studying the geodynamic processes of crustal thickening and expansion of the Qinghai-Xizang Plateau. We conducted a joint inversion of receiver functions and surface wave dispersions with P-wave velocity constraints using data from the Chin Array Ⅱ temporary stations deployed across the Qinghai-Xizang Plateau. Prior to joint inversion, we applied the H-κ-c method(Li JT et al., 2019) to the receiver function data in order to correct for the back-azimuthal variations in the arrival times of Ps phases and crustal multiples caused by crustal anisotropy and dipping interfaces. High-resolution images of vS, crustal thickness, and vP/vSstructures in the Qinghai-Xizang Plateau were simultaneously derived from the joint inversion. The seismic images reveal that crustal thickness decreases outward from the Qinghai-Xizang Plateau. The stable interiors of the Ordos and Alxa blocks exhibited higher velocities and lower crustal vP/vSratios. While, lower velocities and higher vP/vSratios were observed beneath the Qilian Orogen and Songpan-Ganzi terrane(SPGZ), which are geologically active and mechanically weak, especially in the mid-lower crust.Delamination or thermal erosion of the lithosphere triggered by hot asthenospheric flow contributes to the observed uppermost mantle low-velocity zones(LVZs) in the SPGZ. The crustal thickness, vS, and vP/vSratios suggest that whole lithospheric shortening is a plausible mechanism for crustal thickening in the Qinghai-Xizang Plateau, supporting the idea of coupled lithospheric-scale deformation in this region. 展开更多
关键词 joint inversion receiver functions surface waves crustal thickness vP/vS ratio NE Qinghai-Xizang Plateau
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Pressure-Controlled Inverse Ratio Ventilation during General Anesthesia for Open Abdominal Surgery Improves Postoperative Pulmonary Function 被引量:3
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作者 Xiuqin Wang Peimin Wang +2 位作者 Kaiguo Wang Tao Jiang Zan Xu 《Journal of Biomedical Science and Engineering》 2016年第1期17-24,共8页
Background: Studies have shown that pressure-controlled ventilation improves alveolar gas distribution. And inverse ratio ventilation has advantages of improving oxygenation in acute respiratory distress syndrome (ARD... Background: Studies have shown that pressure-controlled ventilation improves alveolar gas distribution. And inverse ratio ventilation has advantages of improving oxygenation in acute respiratory distress syndrome (ARDS) patients. However, the effects that pressure-controlled inverse ration ventilation in patients undergoes endotracheal intubation general anesthesia have not been assessed. Objective: To investigate whether pressure-controlled inverse ratio ventilation (PIV) would improve ventilatory and oxygenation parameters as well as lung function compared to conventional ventilation in patients undergoing open abdominal surgery. Interventions: In the conventional ventilation (CV) group, the ventilation strategy involved zero end-expiratory pressure and volume-controlled ventilation. In the pressure-controlled inverse ratio ventilation (PIV) group, the strategy involved P high starting at 7 cm H<sub>2</sub>O, P low starting at 4 cm H<sub>2</sub>O, T high at 4 s, T low at 2 s, and an inspiratory-to-expiratory time ratio of 2:1. The ΔP value was adjusted according to VT. Pressure levels were increased by 2 cm H<sub>2</sub>O until a maximal V<sub>T</sub> was observed. Inspired oxygen fraction (FIO<sub>2</sub>) was 1.0 and tidal volume (V<sub>T</sub>) was 6 mL/kg in both groups. Main Outcome Measures: The primary outcome is pulmonary function tests. Hemodynamic, ventilatory and oxygenation parameters were measured;visual analog scale (VAS) scores, and nausea and vomiting scores were also measured. Results: The PIV group tolerated pressure-controlled inverse ratio ventilation without significant hemodynamic instability. Mean airway pressure and static compliance were significantly higher in the PIV group than those in CV group (P P 2 h was well tolerated and improved respiratory compliance and lung function on the first postoperative day. 展开更多
关键词 inverse Ratio Ventilation Conventional Ventilation General Anesthesia Lung function
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Inverse Spectral Problem for Sturm-Liouville Operator with Boundary and Jump Conditions Dependent on the Spectral Parameter
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作者 Hui Zhao Jijun Ao 《Journal of Applied Mathematics and Physics》 2024年第3期982-996,共15页
In this paper, the inverse spectral problem of Sturm-Liouville operator with boundary conditions and jump conditions dependent on the spectral parameter is investigated. Firstly, the self-adjointness of the problem an... In this paper, the inverse spectral problem of Sturm-Liouville operator with boundary conditions and jump conditions dependent on the spectral parameter is investigated. Firstly, the self-adjointness of the problem and the eigenvalue properties are given, then the asymptotic formulas of eigenvalues and eigenfunctions are presented. Finally, the uniqueness theorems of the corresponding inverse problems are given by Weyl function theory and inverse spectral data approach. 展开更多
关键词 inverse Problem Sturm-Liouville Operator Weyl function Eigenparameter-Dependent Jump Conditions
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A New Method for Calculating Inverse Involute Functions with High Precision
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作者 Zhou Ruzhong School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China 《Journal of Modern Transportation》 1997年第1期70-72,共3页
Two equations are presented for calculating inverse involute functions. Precise values can be obtained easily with an ordinary calculator.
关键词 inverse involute PRECISION trigonometric function
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Analytical solution of modified point kinetics equations for linear reactivity variation in subcritical nuclear reactors adopting an incomplete gamma function approximation
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作者 André Luiz Pereira Rebello Junior Aquilino Senra Martinez Alessandro da Cruz Goncalves 《Natural Science》 2012年第11期919-923,共5页
The present work aims to achieve a fast and accurate analytical solution of the point kinetics equations applied to subcritical reactors such as ADS (Accelerator-Driven System), assuming a linear reactivity and extern... The present work aims to achieve a fast and accurate analytical solution of the point kinetics equations applied to subcritical reactors such as ADS (Accelerator-Driven System), assuming a linear reactivity and external source variation. It was used a new set of point kinetics equations for subcritical systems based on the model proposed by Gandini & Salvatores. In this work it was employed the integrating factor method. The analytical solution for the case of interest was obtained by using only an approximation which consists of disregarding the term of the second derivative for neutron density in relation to time when compared with the other terms of the equation. And also, it is proposed an approximation for the upper incomplete gamma function found in the solution in order to make the computational processing faster. In addition, for purposes of validation and comparison a numerical solution was obtained by the finite differences method. Finally, it can be concluded that the obtained solution is accurate and has fast numerical processing time, especially when compared with the results of numerical solution by finite difference. One can also observe that the gamma approximation used achieve a high accuracy for the usual parameters. Thus we got satisfactory results when the solution is applied to practical situations, such as a reactor startup. 展开更多
关键词 Accelerator-Driven System SUBCRITICAL Reactors POINT Kinetics Equations incomplete Gamma functions
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Degeneracy Cases of Generalized Inverse Function-Valued Padé Approximation 被引量:1
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作者 潘宝珍 顾传青 《Journal of Shanghai University(English Edition)》 CAS 2004年第3期258-263,共6页
A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discusse... A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discussed and constructed. An example was given to illustrate its application. 展开更多
关键词 Generalized inverse function-valued Padé approximation (GIFPA) degeneracy cases existence and uniqueness.
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Inverse Limit of Spaces of Upper Semicontinuous Functions
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作者 张德学 《Northeastern Mathematical Journal》 CSCD 2001年第1期49-52,共4页
Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor o... Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor on compact Hausdorff space. It is proved in this note that this functor preserves inverse limits. 展开更多
关键词 upper semicontinuous function continuous lattice lim inf convergence inverse limit
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Logarithm of a Function, a Well-Posed Inverse Problem
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作者 Silvia Reyes Mora Víctor A. Cruz Barriguete Denisse Guzmán Aguilar 《American Journal of Computational Mathematics》 2014年第1期1-5,共5页
It poses the inverse problem that consists in finding the logarithm of a function. It shows that when the function is holomorphic in a simply connected domain , the solution at the inverse problem exists and is unique... It poses the inverse problem that consists in finding the logarithm of a function. It shows that when the function is holomorphic in a simply connected domain , the solution at the inverse problem exists and is unique if a branch of the logarithm is fixed. In addition, it’s demonstrated that when the function is continuous in a domain , where is Hausdorff space and connected by paths. The solution of the problem exists and is unique if a branch of the logarithm is fixed and is stable;for what in this case, the inverse problem turns out to be well-posed. 展开更多
关键词 LOGARITHM function inverse PROBLEM STABILITY
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A Comprehensive Price Prediction System Based on Inverse Multiquadrics Radial Basis Function for Portfolio Selection
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作者 Mengmeng Zheng 《Applied Mathematics》 2021年第12期1189-1209,共21页
Price prediction plays a crucial role in portfolio selection (PS). However, most price prediction strategies only make a single prediction and do not have efficient mechanisms to make a comprehensive price prediction.... Price prediction plays a crucial role in portfolio selection (PS). However, most price prediction strategies only make a single prediction and do not have efficient mechanisms to make a comprehensive price prediction. Here, we propose a comprehensive price prediction (CPP) system based on inverse multiquadrics (IMQ) radial basis function. First, the novel radial basis function (RBF) system based on IMQ function rather than traditional Gaussian (GA) function is proposed and centers on multiple price prediction strategies, aiming at improving the efficiency and robustness of price prediction. Under the novel RBF system, we then create a portfolio update strategy based on kernel and trace operator. To assess the system performance, extensive experiments are performed based on 4 data sets from different real-world financial markets. Interestingly, the experimental results reveal that the novel RBF system effectively realizes the integration of different strategies and CPP system outperforms other systems in investing performance and risk control, even considering a certain degree of transaction costs. Besides, CPP can calculate quickly, making it applicable for large-scale and time-limited financial market. 展开更多
关键词 Comprehensive Price Prediction Portfolio Selection (PS) inverse Multiquadrics (IMQ) Radial Basis function
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ON SIMULTANEOUS APPROXIMATION TO A DIFFERENTIABLE FUNCTION AND ITS DERIVATIVE BY INVERSE PAL-TYPE INTERPOLATION POLYNOMIALS
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作者 Bao Yongguang (Hangzhou University, China) 《Analysis in Theory and Applications》 1995年第4期15-23,共9页
Let ξn-1<ξn-2 <ξn-2 <… < ξ1 be the zeros of the the (n -1)-th Legendre polynomial Pn-1(x) and - 1 = xn < xn-1 <… < x1 = 1 the zeros of the polynomial W n(x) =- n(n - 1) Pn-1(t)dt = (1 -x2)P&... Let ξn-1<ξn-2 <ξn-2 <… < ξ1 be the zeros of the the (n -1)-th Legendre polynomial Pn-1(x) and - 1 = xn < xn-1 <… < x1 = 1 the zeros of the polynomial W n(x) =- n(n - 1) Pn-1(t)dt = (1 -x2)P'n-1(x). By the theory of the inverse Pal-Type interpolation, for a function f(x) ∈ C[-1 1], there exists a unique polynomial Rn(x) of degree 2n - 2 (if n is even) satisfying conditions Rn(f,ξk) = f(∈ek)(1≤ k≤ n - 1) ;R'n(f,xk) = f'(xk)(1≤ k≤ n). This paper discusses the simultaneous approximation to a differentiable function f by inverse Pal-Type interpolation polynomial {Rn(f,x)} (n is even) and the main result of this paper is that if f ∈ C'[1,1], r≥2, n≥ + 2> and n is even thenholds uniformly for all x ∈ [- 1,1], where h(x) = 1 + 展开更多
关键词 MATH In ON SIMULTANEOUS APPROXIMATION TO A DIFFERENTIABLE function AND ITS DERIVATIVE BY inverse PAL-TYPE INTERPOLATION POLYNOMIALS PAL ITS
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Adaptive inverse control of random vibration based on the filtered-X LMS algorithm 被引量:10
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作者 Yang Zhidong,Huang Qitao~(++),Han Junwei~§and Li Hongren~§National Key Laboratory of Robots Technique and System,Harbin Institute of Technology,Harbin 150080,China PhD Candidate ~++ PhD ~§Professor 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期141-146,共6页
Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple fre... Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple frequency response functions (FRFs), which lengthens the control loop time in the equalization process. Likewise, the feedback control algorithm has a very slow convergence rate due to the small value of the feedback gain parameter to ensure stability of the system. To overcome these limitations, an adaptive inverse control of random vibrations based on the filtered-X least mean-square (LMS) algorithm is proposed. Furthermore, according to the description and iteration characteristics of random vibration tests in the frequency domain, the frequency domain LMS algorithm is adopted to refine the inverse characteristics of the FRF instead of the traditional time domain LMS algorithm. This inverse characteristic, which is called the impedance function of the system under control, is used to update the drive PSD directly. The test results indicated that in addition to successfully avoiding the instability problem that occurs during the iteration process, the adaptive control strategy minimizes the amount of time needed to obtain a short control loop and achieve equalization. 展开更多
关键词 random vibration power spectral density frequency response function adaptive inverse control filtered-X LMS algorithm
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Stepwise joint inversion of surface wave dispersion,Rayleigh wave ZH ratio,and receiver function data for 1D crustal shear wave velocity structure 被引量:9
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作者 Ping Zhang Huajian Yao 《Earthquake Science》 CSCD 2017年第5期229-238,共10页
Accurate determination of seismic velocity of the crust is important for understanding regional tectonics and crustal evolution of the Earth. We propose a stepwise joint linearized inversion method using surface wave ... Accurate determination of seismic velocity of the crust is important for understanding regional tectonics and crustal evolution of the Earth. We propose a stepwise joint linearized inversion method using surface wave dispersion, Rayleigh wave ZH ratio (i.e., ellipticity), and receiver function data to better resolve 1D crustal shear wave velocity (Vs) structure. Surface wave dispersion and Rayleigh wave ZH ratio data are more sensitive to absolute variations of shear wave speed at depths, but their sensi- tivity kernels to shear wave speeds are different and complimentary. However, receiver function data are more sensitive to sharp velocity contrast (e.g., due to the existence of crustal interfaces) and Vp/Vs ratios. The stepwise inversion method takes advantages of the complementary sensitivities of each dataset to better constrain the Vs model in the crust. We firstly invert surface wave dispersion and ZH ratio data to obtain a 1D smooth absolute vs model and then incorporate receiver function data in the joint inver- sion to obtain a finer Vs model with better constraints on interface structures. Through synthetic tests, Monte Carlo error analyses, and application to real data, we demonstrate that the proposed joint inversion method can resolve robust crustal Vs structures and with little initial model dependency. 展开更多
关键词 Joint inversion Receiver function Surfacewave dispersion Rayleigh wave ZH ratio· Shearwave velocity
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Two optimization algorithms for solving robotics inverse kinematics with redundancy 被引量:5
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作者 Jianxin XU, Wei WANG, Yuanguang SUN (Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576) 《控制理论与应用(英文版)》 EI 2010年第2期166-175,共10页
The kinematic redundancy in a robot leads to an infinite number of solutions for inverse kinematics, which implies the possibility to select a 'best' solution according to an optimization criterion. In this pa... The kinematic redundancy in a robot leads to an infinite number of solutions for inverse kinematics, which implies the possibility to select a 'best' solution according to an optimization criterion. In this paper, two optimization objective functions are proposed, aiming at either minimizing extra degrees of freedom (DOFs) or minimizing the total potential energy of a multilink redundant robot. Physical constraints of either equality or inequality types are taken into consideration in the objective functions. Since the closed-form solutions do not exist in general for highly nonlinear and constrained optimization problems, we adopt and develop two numerical methods, which are verified to be effective and precise in solving the two optimization problems associated with the redundant inverse kinematics. We first verify that the well established trajectory following method can precisely solve the two optimization problems, but is computation intensive. To reduce the computation time, a sequential approach that combines the sequential quadratic programming and iterative Newton-Raphson algorithm is developed. A 4-DOF Fujitsu Hoap-1 humanoid robot arm is used as a prototype to validate the effectiveness of the proposed optimization solutions. 展开更多
关键词 inverse kinematics Redundant robot Objective function OPTIMIZATION Numerical approach
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Reflection full-waveform inversion using a modified phase misfit function
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作者 崔超 黄建平 +2 位作者 李振春 廖文远 关哲 《Applied Geophysics》 SCIE CSCD 2017年第3期407-418,461,共13页
Reflection full-waveform inversion (RFWI) updates the low- and high- wavenumber components, and yields more accurate initial models compared with conventional full-waveform inversion (FWI). However, there is stron... Reflection full-waveform inversion (RFWI) updates the low- and high- wavenumber components, and yields more accurate initial models compared with conventional full-waveform inversion (FWI). However, there is strong nonlinearity in conventional RFWI because of the lack of low-frequency data and the complexity of the amplitude. The separation of phase and amplitude information makes RFWI more linear. Traditional phase-calculation methods face severe phase wrapping. To solve this problem, we propose a modified phase-calculation method that uses the phase-envelope data to obtain the pseudo phase information. Then, we establish a pseudophase-information-based objective function for RFWI, with the corresponding source and gradient terms. Numerical tests verify that the proposed calculation method using the phase-envelope data guarantees the stability and accuracy of the phase information and the convergence of the objective function. The application on a portion of the Sigsbee2A model and comparison with inversion results of the improved RFWI and conventional FWI methods verify that the pseudophase-based RFWI produces a highly accurate and efficient velocity model. Moreover, the proposed method is robust to noise and high frequency. 展开更多
关键词 Reflection full-waveform inversion full-waveform inversion misfit function
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