Inverse Problems in Science and Engineering最新文献_第4页

Determination of singular value truncation threshold for regularization in ill-posed problems 不适定问题正则化奇异值截断阈值的确定

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-08-03 DOI: 10.1080/17415977.2020.1832090

Shuyong Duan, Bo Yang, F. Wang, Guirong Liu

{"title":"Determination of singular value truncation threshold for regularization in ill-posed problems","authors":"Shuyong Duan, Bo Yang, F. Wang, Guirong Liu","doi":"10.1080/17415977.2020.1832090","DOIUrl":"https://doi.org/10.1080/17415977.2020.1832090","url":null,"abstract":"Appropriate regularization parameter specification is the linchpin for solving ill-posed inverse problems when regularization method is applied. This paper presents a novel technique to determine cut off singular values in the truncated singular value decomposition (TSVD) methods. Simple formulae are presented to calculate the index number of the singular value, beyond which all the smaller singular values and the corresponding vectors are truncated. The determination method of optimal truncation threshold is firstly theoretically inferred. Two-dimensional inverse problems processing Radon transform are then exemplified. Formulae to solve the problem with insufficient image resolution and projection angle number are derived by the currently proposed method. The results show that accuracy of the current method is similar to that of TSVD but with much superior efficiency. On the other hand, insufficiency in input data affects the output accuracy of the inverse solution, a least square method can be engaged to establish formulae calculating the truncation threshold. For an insufficient set of input data, the percentage difference between inversely reconstructed signal and TSVD reconstructed signal is about 3%. The current formulae offer reliable and more efficient approach to calculate the truncation threshold when TSVD is applied to solve inverse problems with known system characteristics.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"1127 - 1157"},"PeriodicalIF":1.3,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2020.1832090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44701718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Carlos José Santos Alves (1966–†2021)

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-30 DOI: 10.1080/17415977.2021.1956207

M. Colaço

引用次数: 0

Bayesian damage identification of simply supported beams from elastostatic data 基于弹塑性数据的简支梁贝叶斯损伤识别

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-29 DOI: 10.1080/17415977.2021.1955875

Iman Tabatabaei Ardekani, J. Kaipio, D. Castello

引用次数: 1

Study of fourth-order boundary value problem based on Volterra–Fredholm equation: numerical treatment 基于Volterra-Fredholm方程的四阶边值问题研究:数值处理

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-22 DOI: 10.1080/17415977.2021.1954178

J. Shokri, S. Pishbin

{"title":"Study of fourth-order boundary value problem based on Volterra–Fredholm equation: numerical treatment","authors":"J. Shokri, S. Pishbin","doi":"10.1080/17415977.2021.1954178","DOIUrl":"https://doi.org/10.1080/17415977.2021.1954178","url":null,"abstract":"This paper presents a study of the performance of the Tau method using Chebyshev basis functions for solving fourth-order differential equation with boundary conditions. Existence and uniqueness of the solution of this equation are investigated transforming it into the Volterra–Fredholm integral equation. We use the operational Tau matrix representation with Chebyshev basis functions for constructing the algebraic equivalent representation of the problem.This representation is an special semi lower triangular system whose solution gives the components of the vector solution. Applying Gronwall’s and the generalized Hardy’s inequality, convergence analysis and error estimation of the Tau method are discussed. The error analysis indicates that the numerical errors decay exponentially when the source function are sufficiently smooth. Illustrative examples are given to represent the efficiency and the accuracy of the proposed method. Also, some comparisons are made with existing results such that the results obtained by Tau method are more accurate than the proposed methods in this case.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2862 - 2876"},"PeriodicalIF":1.3,"publicationDate":"2021-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1954178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42908384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Enhanced features in principal component analysis with spatial and temporal windows for damage identification 用于损伤识别的具有空间和时间窗口的主成分分析中的增强特征

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-20 DOI: 10.1080/17415977.2021.1954921

Ge Zhang, Liqun Tang, Zejia Liu, Licheng Zhou, Yiping Liu, Zhenyu Jiang, Jingsong Chen, S. Sun

{"title":"Enhanced features in principal component analysis with spatial and temporal windows for damage identification","authors":"Ge Zhang, Liqun Tang, Zejia Liu, Licheng Zhou, Yiping Liu, Zhenyu Jiang, Jingsong Chen, S. Sun","doi":"10.1080/17415977.2021.1954921","DOIUrl":"https://doi.org/10.1080/17415977.2021.1954921","url":null,"abstract":"Principal component analysis (PCA) methods have been widely applied to damage identification in the long-term structural health monitoring (SHM) of infrastructure. Usually, the first few eigenvector components derived by PCA methods are treated as damage-sensitive features. In this paper, the effective method of double-window PCA (DWPCA) and novel features are proposed for better damage identification performance. In the proposed method, spatial and temporal windows are introduced to the traditional PCA method. The spatial windows are applied to group damage-sensitive sensors and exclude those sensors insensitive to damage, while the temporal window is applied to better discriminate eigenvectors between the damaged and healthy states. In addition, the length and directional angle of the eigenvector variation between the healthy and damaged states are used as the damage-sensitive features, instead of the components of the eigenvector variation used in previous studies. Numerical simulations based on a large-scale bridge reveal that the proposed features are successful in identifying the damage located far from sensors due to the use of both spatial and temporal windows as well as the length of the eigenvector variation. In addition, compared to the previous PCA and moving PCA methods, the novel features have higher sensitivity and resolution in damage identification.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2877 - 2894"},"PeriodicalIF":1.3,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1954921","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42114907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Fault identification in cracked rotor-AMB system using magnetic excitations based on multi harmonic influence coefficient method 基于多谐波影响系数法的磁激励裂纹转子磁悬浮轴承系统故障识别

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-17 DOI: 10.1080/17415977.2021.1952409

Gyan Ranjan, R. Tiwari, H. Nemade

{"title":"Fault identification in cracked rotor-AMB system using magnetic excitations based on multi harmonic influence coefficient method","authors":"Gyan Ranjan, R. Tiwari, H. Nemade","doi":"10.1080/17415977.2021.1952409","DOIUrl":"https://doi.org/10.1080/17415977.2021.1952409","url":null,"abstract":"On-site estimation of multiple fault parameters has been performed in a rotor integrated with active-magnetic bearing (AMB) with a cracked shaft supported on flexible conventional bearings. In addition to external viscous damping (at flexible bearings), internal damping (at transverse crack) is considered to show its influence on the dynamics of the cracked system. The instability generated in the rotor system due to the effect of internal damping at high speed are reduced with the control action of the AMB. A Multiple Harmonic Influence Coefficient Method (MHICM) has been proposed that requires the full spectrum amplitude and phases of the rotor responses and excitation forces to obtain the fault parameters of the rotor. The additive crack stiffness, residual unbalances, and internal damping can be estimated in the operating condition with less information on the rotor system. The intensity of the fault parameters is required to be monitored periodically to identify the safe operating speed of the system. As the AMB is an integral part of the rotor system, the multi-harmonic excitation can be initiated without changing the physical condition of the system. To check the robustness of the algorithm, different percentages of random noise are added to the rotor responses.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2831 - 2861"},"PeriodicalIF":1.3,"publicationDate":"2021-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1952409","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46414781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

A homogenization method to solve inverse Cauchy–Stefan problems for recovering non-smooth moving boundary, heat flux and initial value 求解Cauchy–Stefan反问题的一种均匀化方法，用于恢复非光滑移动边界、热通量和初始值

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-08 DOI: 10.1080/17415977.2021.1949591

Chein-Shan Liu, Jiang-Ren Chang

{"title":"A homogenization method to solve inverse Cauchy–Stefan problems for recovering non-smooth moving boundary, heat flux and initial value","authors":"Chein-Shan Liu, Jiang-Ren Chang","doi":"10.1080/17415977.2021.1949591","DOIUrl":"https://doi.org/10.1080/17415977.2021.1949591","url":null,"abstract":"In the paper, we solve two Stefan problems. The first problem recovers an unknown moving boundary by specifying the Cauchy boundary conditions on a fixed left-end. The second problem finds a time-dependent heat flux on the left-end, such that a desired moving boundary can be achieved. Then, we solve an inverse Cauchy-Stefan problem, using the over-specified Cauchy boundary conditions on a given moving boundary to recover the solution. Resorting on a homogenization function method, we recast these problems into the ones having homogeneous boundary and initial conditions. Consequently, the approximate solution is obtained by solving a linear system obtained from the collocation method in a reduced domain. For the first Stefan problem the moving boundary can be determined accurately, after solving a nonlinear equation at each discretized time. For the second Stefan problem, we can obtain the required boundary heat flux without needing of iteration. Numerical examples, including non-smooth ones, confirm that the novel methods are simple and robust against large noise. Moreover, the Stefan and inverse Cauchy-Stefan problems are solved without initial conditions.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2772 - 2803"},"PeriodicalIF":1.3,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1949591","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42904894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal characterization of complex shape composite materials using Karhunen–Loève decomposition techniques 使用Karhunen–Loève分解技术对复杂形状复合材料的热表征

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-07 DOI: 10.1080/17415977.2021.1945050

M. Mint Brahim, A. Godin, M. Azaïez, E. Palomo Del Barrio

{"title":"Thermal characterization of complex shape composite materials using Karhunen–Loève decomposition techniques","authors":"M. Mint Brahim, A. Godin, M. Azaïez, E. Palomo Del Barrio","doi":"10.1080/17415977.2021.1945050","DOIUrl":"https://doi.org/10.1080/17415977.2021.1945050","url":null,"abstract":"A new method for estimating the thermal properties of composite materials is proposed. It uses a previously developed thermal characterization method that is based on Karhunen–Loève decomposition (KLD) techniques in association with infrared thermography experiments or any other kind of experimental device providing dense data in spatial coordinates. The novelty of this work lies in the introduction of two techniques based on two phase-wise defined test functions that extend the previously developed method to cases where the morphology of the composite material is not straightforward. Thanks to the orthogonal properties of KLD, only a few eigenelements are needed for an accurate estimation, which allows for a significant amplification of the signal/noise ratios. Furthermore, the proposed methods represent an attractive combination of parsimony and robustness to noise thanks to spatially uncorrelated noise being entirely reported on states. The effectiveness and accuracy of both techniques are proven with numerical tests.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2676 - 2695"},"PeriodicalIF":1.3,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1945050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49565826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Recovering space-dependent source for a time-space fractional diffusion wave equation by fractional Landweber method 用分数阶Landweber法恢复时空分数阶扩散波方程的空间依赖源

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-03 DOI: 10.1080/17415977.2020.1815724

S. Jiang, Yujiang Wu

引用次数: 4

A locally sequential refinement of the growth dynamics identification 生长动力学识别的局部序列精化

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-07-02 DOI: 10.1080/17415977.2021.1948025

Mikhail Rem Romanovski

{"title":"A locally sequential refinement of the growth dynamics identification","authors":"Mikhail Rem Romanovski","doi":"10.1080/17415977.2021.1948025","DOIUrl":"https://doi.org/10.1080/17415977.2021.1948025","url":null,"abstract":"The approach is developed to specify a reconstruction of complicated functions using samples of limited size with invariant properties regarding the desired parameters. The idea is based on solutions to inverse problems, which should identify various representations of unknown parameters of a mathematical model and do so in a series. The sequential solutions to inverse problems ensure the identifiability of desired parameters that belong to an invariant family. The locally sequential refinement restricts local spikes additionally to the general regularization under a scheme of separate matching with observations. A simulation with inverse problems is applied to refine the known features of population dynamics. The reconstruction shows that the parameters of the Verhulst equation should be introduced as oscillatory functions. Based on the novel functional representation of the Verhulst equation parameters, the patterns of the COVID-19 spread and its progression in a given region are determined. The results emphasize the Verhulst equation’s character as a generalized and fruitful model for an object growth simulation.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"2719 - 2756"},"PeriodicalIF":1.3,"publicationDate":"2021-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1948025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46247385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1