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Algorithms and statistical analysis for linear structured weighted total least squares problem
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作者 Jian Xie Tianwei Qiu +2 位作者 Cui Zhou Dongfang Lin Sichun Long 《Geodesy and Geodynamics》 EI CSCD 2024年第2期177-188,共12页
Weighted total least squares(WTLS)have been regarded as the standard tool for the errors-in-variables(EIV)model in which all the elements in the observation vector and the coefficient matrix are contaminated with rand... Weighted total least squares(WTLS)have been regarded as the standard tool for the errors-in-variables(EIV)model in which all the elements in the observation vector and the coefficient matrix are contaminated with random errors.However,in many geodetic applications,some elements are error-free and some random observations appear repeatedly in different positions in the augmented coefficient matrix.It is called the linear structured EIV(LSEIV)model.Two kinds of methods are proposed for the LSEIV model from functional and stochastic modifications.On the one hand,the functional part of the LSEIV model is modified into the errors-in-observations(EIO)model.On the other hand,the stochastic model is modified by applying the Moore-Penrose inverse of the cofactor matrix.The algorithms are derived through the Lagrange multipliers method and linear approximation.The estimation principles and iterative formula of the parameters are proven to be consistent.The first-order approximate variance-covariance matrix(VCM)of the parameters is also derived.A numerical example is given to compare the performances of our proposed three algorithms with the STLS approach.Afterwards,the least squares(LS),total least squares(TLS)and linear structured weighted total least squares(LSWTLS)solutions are compared and the accuracy evaluation formula is proven to be feasible and effective.Finally,the LSWTLS is applied to the field of deformation analysis,which yields a better result than the traditional LS and TLS estimations. 展开更多
关键词 linear structured weighted total least SQUARES ERRORS-IN-VARIABLES Errors-in-observations Functional modelmodification Stochastic model modification Accuracyevaluation
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RECURSIVENESS OF ZERO STRUCTURES FOR SYSTEM MATRICES OF INTERCONNECTED LINEAR SYSTEMS VIA MODULE THEORETIC TOOLS
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作者 M. De la Sen 《Analysis in Theory and Applications》 1997年第3期29-46,共18页
The importance of the zeros of multwariable linear systems is well-knoiun in terms of measure obstructions to the controllability and the. observability. In this paper, a recursive decarnposi Am oj interconnected syst... The importance of the zeros of multwariable linear systems is well-knoiun in terms of measure obstructions to the controllability and the. observability. In this paper, a recursive decarnposi Am oj interconnected systems is outlined by taking into account the sequential structure of the connnections. The paper extends the, coordinate, module-theoretic studies from the elementary algebraic systems theory to include the case oj such linear interconnected systems which need not to be controllable or observable. Also, the properties of controllability and observability, the decoupling zeros and the signal Making issues are characterized. 展开更多
关键词 maps RECURSIVENESS OF ZERO structures FOR SYSTEM MATRICES OF INTERCONNECTED linear SYSTEMS VIA MODULE THEORETIC TOOLS
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Separate Analysis of Remote Sensing Information of Structures of Different Geological Periods and Quantitative Study of Corresponding Tectonic Stress Fields 被引量:1
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作者 Yang Wunian and Zhu Zhangsen Institute of Remote Sensing and GIS, Chengdu University of Technology,Chengdu, Sichuan Liu Xinzhu Yang Wencai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第3期344-354,共11页
The structural feature shown on a remote sensing image is a synthetic result ofcombination of the deformations produced during the entire geological history of an area.Therefore, the respective tectonic stress field o... The structural feature shown on a remote sensing image is a synthetic result ofcombination of the deformations produced during the entire geological history of an area.Therefore, the respective tectonic stress field of each of the different stages in the complexdeformation of an area can be reconstructed in three steps: (1) geological structures formed atdifferent times are distinguished in remote sensing image interpretation; (2) structuraldeformation fields at different stages are determined by analyzing relationships betweenmicrostructures (joints and fractures) and the related structures (folds and faults); and (3)tectonic stress fields at different stages are respectively recovered through a study of the featuresof structural deformation fields in different periods. Circular structures and related circlular and radial joints are correlated in space to con-cealed structural rises. The authors propose a new method for establishing a natural model ofthe concealed structural rises and calculating the tectonic stress field by using quantitative dataof the remote sensing information of circular structures and related linear structures. 展开更多
关键词 separate analysis of the remote sensing information field circular structure linear structure stress field quantitative analysis 3—dimensional colour structural block diagram
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Novel Poly m eric Transition Metal Co m plexes Having1D Chain and 3D Networks Structures
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作者 洪茂椿 曹荣 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1999年第5期384-392,共9页
The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assemblin... The syntheses and structures of eleven novel polymeric transition metal complexes having one dimensional chain structures or three dimensional networks are summarized. They are prepared from the controlled assembling reactions in organic solvents and characterized by X ray diffraction analyses. The spectroscopic or magnetic properties of some complexes are studied. 展开更多
关键词 polymeric metal complex linear chain structure 3D network
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SYNTHESIS AND STRUCTURE OF A LINEAR TRIVANADIUM COMPOUND(Ph_4P)[V_3(OC_6H_4S-o)_6]-SIMULATION OF THE VANADIUM SITE OF ALTERNATIVE NITROGENASE
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作者 Bei Sheng KANG Ling Hong WENG Liang Ren HUANG Xue Tai CHEN Han Qin LIU Jia Xi LU Fuzhou Laboratory of Structural Chemistry andFujian Institute of Research on the Structure of Matter Chinese Academy of Sciences,Fuzhou 350002 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第1期79-80,共2页
Compound(Ph_4P)[V_3MP_6](MPH_2=o-HOC_6H_4SH)was obtained by reaction of VCl_3 and Na_2MP in ethanol in the presence of Ph_4PBr.It is triclinic and crystallizes in space group P1,fw=1237.3,a=14.127(4), b=14.342(4),c=15... Compound(Ph_4P)[V_3MP_6](MPH_2=o-HOC_6H_4SH)was obtained by reaction of VCl_3 and Na_2MP in ethanol in the presence of Ph_4PBr.It is triclinic and crystallizes in space group P1,fw=1237.3,a=14.127(4), b=14.342(4),c=15.878(4);α=65.08(2),β=73.09(2),T=78.68(2)°;V=2781.3~3, Z=2,d_c=1.48 g/cm^3.Final R factor is 0.063.The three vanadium atoms are linearly arranged and bridged by the oxygen atoms and terminally chelated by the thiolato-atoms of the six MP^2-ligands in pseudo-S_6 symmetry. 展开更多
关键词 Ph4P SIMULATION OF THE VANADIUM SITE OF ALTERNATIVE NITROGENASE SYNTHESIS AND STRUCTURE OF A linear TRIVANADIUM COMPOUND V3 SITE Figure Wang
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ON THE DEGREE OF COMPLETENESS OF CRYPTOGRAPHIC FUNCTIONS 被引量:1
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作者 Liu Jian Chen Lusheng 《Journal of Electronics(China)》 2014年第5期489-495,共7页
This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the relationships between the d... This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the relationships between the degree of completeness and other cryptographic criteria. For resilient Boolean functions, a method to enhance the degree of completeness is proposed, while the nonlinearity and the algebraic degree do not decrease. Moreover, two constructions of resilient functions are provided, which have optimal degree of completeness, high nonlinearity, and high algebraic degree. 展开更多
关键词 Degree of completeness Multi-output Boolean functions NONlinearITY Resiliency linear structures
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On-line detection system of weld-based rapid prototyping process based on structured light 被引量:2
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作者 李永哲 张广军 +1 位作者 熊俊 吴林 《China Welding》 EI CAS 2013年第1期1-5,共5页
In order to realize the closed-loop control for rapid prototyping process based on gas metal arc welding, the geometric parameters of weld beads should be detected. In this study, a vision sensor system consisting of ... In order to realize the closed-loop control for rapid prototyping process based on gas metal arc welding, the geometric parameters of weld beads should be detected. In this study, a vision sensor system consisting of a linear laser projector and a CCD camera was designed to collect images of weld beads. Then, an image processing approach which combines with a Gaassian filter and an improved gravity method was used to extract the centerline of a light stripe based on VC ++. Feature points of the centerline were identical directly by means of an image fusion algorithm. Experimental results show that image fusion is an effective approach to measure the width and height of the weld bead with high accuracy. This method can identify beads effectively in multi-pass welding and avoid designing different modes to suit all kinds of shapes. 展开更多
关键词 weld-based rapid prototyping linear structured light image processing image fusion
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The inversion of 3-D crustal structure and hypocenter location in the Beijing-Tianjin-Tangshan-Zhangjiakou area by genetic algorithm 被引量:1
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作者 万永革 刘瑞丰 李鸿吉 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第6期74-86,共13页
This paper discusses the inversion of velocity structure and hypocenters location in the Beijing Tianjin Tangshan Zhangjiakou area by genetic algorithm. The hypocenters location of sele... This paper discusses the inversion of velocity structure and hypocenters location in the Beijing Tianjin Tangshan Zhangjiakou area by genetic algorithm. The hypocenters location of selected earthquakes and crustal structure of this area are obtained using the travel time data of local earthquakes acquired by the Telemetered Seismic Network of Northern China. The mean and standard residuals of hypocenter location acquired by this method are much less than those provided by the report of respective earthquakes. The crustal structure of the first and the second layers obtained interpret the outline of the plain and mountain area in the region successfully and the crustal structure of the third layer nearly coincides with the Moho discontinuity obtained by artificial seismic sounding. These show the genetic algorithm is effective to the inversion of hypocenter location and three dimensional velocity structure. 展开更多
关键词 genetic algorithm hypocenter crustal structure inversion non linear
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Whether Different Rhetoric between Chinese and English Will Influence the Reading Comprehension of the Chinese Students 被引量:1
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作者 潘春 《海外英语》 2018年第8期198-198,203,共2页
In this article, the general text structure of English and Chinese will be stated respectively at first. Then the issue of whether different rhetoric between Chinese and English will influence the reading comprehensio... In this article, the general text structure of English and Chinese will be stated respectively at first. Then the issue of whether different rhetoric between Chinese and English will influence the reading comprehension of the Chinese students will be analyzed and evaluated. 展开更多
关键词 rhetoric structure linear structure circular structure
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Research on Image Quality Enhancement Algorithm Using Hessian Matrix
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作者 Xi Chen Yanpeng Wu +1 位作者 Chenxue Zhu Hongjun Liu 《Journal of New Media》 2022年第3期117-123,共7页
The Hessian matrix has a wide range of applications in image processing,such as edge detection,feature point detection,etc.This paper proposes an image enhancement algorithm based on the Hessian matrix.First,the Hessi... The Hessian matrix has a wide range of applications in image processing,such as edge detection,feature point detection,etc.This paper proposes an image enhancement algorithm based on the Hessian matrix.First,the Hessian matrix is obtained by convolving the derivative of the Gaussian function.Then use the Hessian matrix to enhance the linear structure in the image.Experimental results show that the method proposed in this paper has strong robustness and accuracy. 展开更多
关键词 Hessian matrix Gaussian function image enhancement linear structure
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An efficient technique for recovering responses of parameterized structural dynamic problems
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作者 Zheng Zhang Xu Han Chao Jiang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第5期757-766,共10页
In this article,an effective technique is developed to efficiently obtain the output responses of parameterized structural dynamic problems.This technique is based on the conception of reduced basis method and the usa... In this article,an effective technique is developed to efficiently obtain the output responses of parameterized structural dynamic problems.This technique is based on the conception of reduced basis method and the usage of linear interpolation principle.The original problem is projected onto the reduced basis space by linear interpolation projection,and subsequently an associated interpolation matrix is generated.To ensure the largest nonsingularity,the interpolation matrix needs to go through a timenode choosing process,which is developed by applying the angle of vector spaces.As a part of this technique,error estimation is recommended for achieving the computational error bound.To ensure the successful performance of this technique,the offline-online computational procedures are conducted in practical engineering.Two numerical examples demonstrate the accuracy and efficiency of the presented method. 展开更多
关键词 Reduced basis method · Structural dynamic response · Real-time computation · linear interpolation · Fast Fourier transform
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Efficient Computational Method for the Non-Probabilistic Reliability of Linear Structural Systems 被引量:5
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作者 Ruixing Wang Xiao jun Wang +1 位作者 Lei Wang Xianjia Chen 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2016年第3期284-299,共16页
The non-probabilistic reliability in higher dimensional situations cannot be calcu- lated efficiently using traditional methods, which either require a large amount of calculation or cause significant error. In this s... The non-probabilistic reliability in higher dimensional situations cannot be calcu- lated efficiently using traditional methods, which either require a large amount of calculation or cause significant error. In this study, an efficient computational method is proposed for the cal- culation of non-probabilistic reliability based on the volume ratio theory, specificMly for linear structural systems. The common expression for non-probabilistic reliability is obtained through formula derivation with the amount of computation considerably reduced. The compatibility be- tween non-probabilistic and probabilistic safety measures is demonstrated through the Monte Carlo simulation. The high efficiency of the presented method is verified by several numerical examples. 展开更多
关键词 non-probabilistic reliability linear structural system formula derivation compatibility high efficiency
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Regional Pole Assignment Robustness for Linear VSC System Subject to Structured Perturbations
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作者 韩云瑞 胡勇 《Tsinghua Science and Technology》 SCIE EI CAS 1998年第4期1236-1239,共4页
An approach is proposed to analyze pole assignment robustness in some specific regions for linear variable structure control systems subject to structured perturbations.A sufficient condition of robustness is presente... An approach is proposed to analyze pole assignment robustness in some specific regions for linear variable structure control systems subject to structured perturbations.A sufficient condition of robustness is presented and the upper bound of structured perturbations which ensure the robustness is computed by numerical analysis. 展开更多
关键词 linear variable structure control systems switching plane pole assignment structured perturbatios ROBUSTNESS
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Exact investigation of the electronic structure and the linear and nonlinear optical properties of conical quantum dots
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作者 M.Dezhkam A.Zakery 《Chinese Optics Letters》 SCIE EI CAS CSCD 2012年第12期52-55,共4页
Intersubband linear and third-order nonlinear optical properties of conical quantum dots with infinite barrier potential are studied. The electronic structure of conical quantum dots through effective mass approximati... Intersubband linear and third-order nonlinear optical properties of conical quantum dots with infinite barrier potential are studied. The electronic structure of conical quantum dots through effective mass approximation is determined analytically. Linear, nonlinear, and total absorption coefficients, as well as the refractive indices of GaAs conical dots, are calculated. The effects of the size of the dots and of the incident electromagnetic field are investigated. Results show that the total absorption coefficient and the refractive index of the dots largely depend on the size of the dots and on the intensity and polarization of the incident electromaenetic field. 展开更多
关键词 In Exact investigation of the electronic structure and the linear and nonlinear optical properties of conical quantum dots RI QDs AC GaAs
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Linear Liquid Responses of Morpho Butterfly Structural Color: Experiment and Modeling
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作者 WU Wenjun XIE Hengfeng +2 位作者 LIAO Guanglan SHI Tielin NIE Lei 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2016年第6期473-481,共9页
This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the... This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the reason of the selective response is that the liquid media forms nanometre-thick films between ridge-lamellae nanostructures and changes the constructive interference wavelength. There is linear relation between the structural color of ridge-lamellae structure and index of liquid background media. The reason of vapor's responses is that the nanometre-thick liquid fi lms on ridge-lamellae nanostructures change the constructive interference wavelength. These liquid films are formed due to vapor adsorption. Therefore,the selective linear liquid response can be applied to design nano-engineered photonic liquid and vapor sensors. 展开更多
关键词 nano-engineered photonic sensors ridge-lamellae nanostructures structural color linear liquid response
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