Inverse Problems in Science and Engineering最新文献_第9页

Simultaneous reconstruction of optical absorption property and speed of sound in intravascular photoacoustic tomography 血管内光声断层成像中光吸收特性和声速的同时重建

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-31 DOI: 10.1080/17415977.2021.1879805

Zheng Sun, Lisen Sun

{"title":"Simultaneous reconstruction of optical absorption property and speed of sound in intravascular photoacoustic tomography","authors":"Zheng Sun, Lisen Sun","doi":"10.1080/17415977.2021.1879805","DOIUrl":"https://doi.org/10.1080/17415977.2021.1879805","url":null,"abstract":"Intravascular photoacoustic tomography (IVPAT) is a newly developed imaging modality for the diagnosis and intervention of coronary artery diseases. It is an ill-posed nonlinear least squares (NLS) problem to recover the absorbed optical energy density (AOED) and optical absorption coefficient (OAC) distribution in the vascular cross sections from pressure photoacoustically generated by tissues with variable speed of sound (SoS). The prior knowledge of the SoS is usually unavailable before IVPAT scanning. The ideal assumption of a constant SoS leads to degraded image quality. This paper focuses on improvement of image quality for IVPAT in tissues with variable SoS by simultaneously recovering the SoS, AOED and OAC from the measured time-dependent pressure series. The joint recovery is implemented by alternately minimizing the errors between the measured and theoretical pressure by forward simulation. The demonstration results indicate that the normalized mean square absolute distance (NMSAD) of the reconstructions produced by this method is decreased by about 15% in comparison to that of the reconstructions with a fixed SoS. Comparison results show that this method outperforms the delay compensation method in recovering the AOED and the two-step algorithm in estimating the OAC by about 20% and 25% in NMSAD respectively.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"1764 - 1788"},"PeriodicalIF":1.3,"publicationDate":"2021-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1879805","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47200527","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

A fast method for simultaneous reconstruction and segmentation in X-ray CT application 一种在X射线CT应用中同时进行重建和分割的快速方法

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-30 DOI: 10.1080/17415977.2021.1999941

Yiqiu Dong, Chunlin Wu, Shi Yan

{"title":"A fast method for simultaneous reconstruction and segmentation in X-ray CT application","authors":"Yiqiu Dong, Chunlin Wu, Shi Yan","doi":"10.1080/17415977.2021.1999941","DOIUrl":"https://doi.org/10.1080/17415977.2021.1999941","url":null,"abstract":"In this paper, we propose a new method to solve the minimization problem in a simultaneous reconstruction and segmentation (SRS) model for X-ray computed tomography (CT). The SRS model uses Bayes' rule and the maximum a posteriori (MAP) estimate on the hidden Markov measure field model (HMMFM). The original method [Romanov M, Dahl AB, Dong Y, Hansen PC. Simultaneous tomographic reconstruction and segmentation with class priors. Inverse Problems Sci Eng. 2016;24(8):1432–1453] includes a subproblem with logarithmic-summation (log-sum) term, which is non-separable to the classification index. This subproblem was solved by Frank–Wolfe algorithm, which is very time consuming especially when dealing with large-scale CT problems. The starting point of this paper is the commutativity of log-sum operations, where the log-sum problem could be transformed into a sum-log problem by introducing an auxiliary variable. The corresponding sum-log problem for the SRS model is separable. By applying the primal-dual algorithm, the sum-log problem turns into several easy-to-solve convex subproblems. In addition, we introduce an improved model by adding Tikhonov regularization on the SRS model, and give some convergence results for the proposed methods. Experimental results demonstrate that the proposed methods produce comparable results compared with the original SRS method with much less CPU time.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"3342 - 3359"},"PeriodicalIF":1.3,"publicationDate":"2021-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45641653","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

Function estimation and regularization in the SIRD model applied to the COVID-19 pandemics 应用于新冠肺炎大流行的SIRD模型中的函数估计和正则化

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-17 DOI: 10.1080/17415977.2021.1872563

C. C. Pacheco, C. R. de Lacerda

引用次数: 10

Inverse problem techniques for multiple crack detection in 2D elastic continua based on extended finite element concepts 基于扩展有限元概念的二维弹性连续体多重裂纹检测反问题技术

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-13 DOI: 10.1080/17415977.2021.1872564

P. Broumand

{"title":"Inverse problem techniques for multiple crack detection in 2D elastic continua based on extended finite element concepts","authors":"P. Broumand","doi":"10.1080/17415977.2021.1872564","DOIUrl":"https://doi.org/10.1080/17415977.2021.1872564","url":null,"abstract":"Two efficient methods are presented to detect multiple cracks in 2D elastic bodies, based on the insights from Extended Finite Element. Adetection mesh is assigned to the cracked body and the responses are measured at the nodes. A finite element model with the same mesh is used to represent the uncracked state of the physical body. In the first method which is called Crack Detection based on Residual Error (CDRE), the residual error norm is calculated based on the uncracked body stiffness matrix and the cracked body responses. The contour of the error norm would show the crack pattern; the method is computationally efficient. In the second method that is coined as Crack Detection based on Stiffness Residual (CDSR), the crack locations are found based on the difference between the stiffness matrix of the cracked body and the uncracked body. The stiffness matrix of the cracked body is found by solving a dynamic inverse problem based on a modified Tikhonov regularization. The efficiency and accuracy of the identification method are enhanced by predicting the crack pattern by the CDRE method. Several examples are presented to show the accuracy and robustness of the methods in the presence of high noise levels.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"1702 - 1728"},"PeriodicalIF":1.3,"publicationDate":"2021-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2021.1872564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47774884","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

Free vibration of the double tapered cracked beam 双锥裂纹梁的自由振动

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-13 DOI: 10.1080/17415977.2020.1870971

M. Haskul, M. Kısa

引用次数: 5

Inverse analysis for rock mechanics based on a high dimensional model representation 基于高维模型表示的岩石力学逆分析

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-11 DOI: 10.1080/17415977.2020.1870972

Hongbo Zhao, Bing-Rui Chen

{"title":"Inverse analysis for rock mechanics based on a high dimensional model representation","authors":"Hongbo Zhao, Bing-Rui Chen","doi":"10.1080/17415977.2020.1870972","DOIUrl":"https://doi.org/10.1080/17415977.2020.1870972","url":null,"abstract":"Mechanical parameters of rock mass are essential in rock engineering for stability analysis, supporting design, and safety construction. The inverse analysis has been commonly used in rock engineering to determine the mechanical parameters of the rock mass. In this study, a novel inverse analysis approach was proposed through combing high dimensional model representation (HDMR), Excel solver, and numerical model. HDMR was employed to approximate the nonlinear function between the mechanical parameters of rock mass and the response of rock based on the numerical model. Excel Solver was adopted to search the mechanical parameters of rock mass based on the HDMR model for the inverse analysis. The proposed method was verified and illustrated the performance of the proposed method by two tunnels. The mechanical parameters of rock mass were determined based on the displacement of surrounding rock mass and HDMR model using the Excel solver for the tunnels. The displacement and stress of surrounding rock mass were computed based on the determined mechanical parameters of rock mass by the proposed method. There was an excellent agreement with the real value or contour that was computed based on the actual mechanical parameters of the rock mass. The results demonstrated that the proposed method was practical and accurate. It also made it convenient to be applied to determine mechanical parameters of rock mass based on monitored information.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"1565 - 1585"},"PeriodicalIF":1.3,"publicationDate":"2021-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2020.1870972","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46484493","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

Grid methods for Bayes-optimal continuous-discrete filtering and utilizing a functional tensor train representation 贝叶斯最优连续离散滤波的网格方法和利用函数张量列表示

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-06 DOI: 10.1080/17415977.2020.1862109

C. Fox, S. Dolgov, Malcolm Morrison, T. Molteno

{"title":"Grid methods for Bayes-optimal continuous-discrete filtering and utilizing a functional tensor train representation","authors":"C. Fox, S. Dolgov, Malcolm Morrison, T. Molteno","doi":"10.1080/17415977.2020.1862109","DOIUrl":"https://doi.org/10.1080/17415977.2020.1862109","url":null,"abstract":"Optimal continuous-discrete filtering for a nonlinear system requires evolving the forward Kolmogorov equation, that is a Fokker–Planck equation, in alternation with Bayes' conditional updating. We present two numerical grid-methods that represent density functions on a mesh, or grid. For low-dimensional, smooth systems the finite-volume method is an effective solver that gives estimates that converge to the optimal continuous-time values. We give numerical examples to show that this finite-volume filter is able to handle multi-modal filtering distributions that result from rank-deficient observations, and that Bayes-optimal parameter estimation may be performed within the filtering process. The naïve discretization of density functions used in the finite-volume filter leads to an exponential increase of computational cost and storage with increasing dimension, that makes the finite-volume filter unfeasible for higher-dimensional problems. We circumvent this ‘curse of dimensionality’ by using a tensor train representation (or approximation) of density functions and employ an efficient implicit PDE solver that operates on the tensor train representation. We present numerical examples of tracking n weakly coupled pendulums in continuous time to demonstrate filtering with complex density functions in up to 80 dimensions.","PeriodicalId":54926,"journal":{"name":"Inverse Problems in Science and Engineering","volume":"29 1","pages":"1199 - 1217"},"PeriodicalIF":1.3,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/17415977.2020.1862109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47341426","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

The estimation of approximation error using inverse problem and a set of numerical solutions 用反问题估计近似误差，并给出一组数值解

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-02 DOI: 10.1080/17415977.2021.2000604

A. Alekseev, A. Bondarev

引用次数: 2

Foreword 前言

IF 1.3 4区工程技术

Inverse Problems in Science and Engineering Pub Date : 2021-01-02 DOI: 10.1080/17415977.2021.1871568

G. Dulikravich

引用次数: 0

A high order PDE-constrained optimization for the image denoising problem 图像去噪问题的高阶PDE约束优化