Anisotropy Across Fields and Scales.

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Bibliographic Details
Superior document:Mathematics and Visualization Series
:
TeilnehmendeR:
Place / Publishing House:Cham : : Springer International Publishing AG,, 2021.
{copy}2021.
Year of Publication:2021
Edition:1st ed.
Language:English
Series:Mathematics and Visualization Series
Online Access:
Physical Description:1 online resource (284 pages)
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Table of Contents:
  • Intro
  • Preface
  • Contents
  • Foundations
  • Variance Measures for Symmetric Positive (Semi-) Definite Tensors in Two Dimensions
  • 1 Introduction
  • 1.1 Outline
  • 2 Preliminaries
  • 2.1 Tensor Notation and Representations
  • 2.2 Invariants, Traces and Decompositions
  • 3 Rabcd as a Quadratic Form on mathbbR3
  • 3.1 Representation of the Canonically Derived Parts of Rabcd
  • 3.2 The Behaviour of Mij Under a Rotation of the Coordinate System in Va
  • 4 The Equivalence Problem for Rabcd
  • 4.1 Different Ways to Characterize the Equivalence of Rabcd and widetildeRabcd
  • 5 Discussion
  • References
  • Degenerate Curve Bifurcations in 3D Linear Symmetric Tensor Fields
  • 1 Introduction
  • 2 Previous Work
  • 3 Background on Tensors and Tensor Fields
  • 3.1 Tensors
  • 3.2 Tensor Field Topology
  • 3.3 3D Linear Tensor Fields
  • 4 Bifurcations
  • 4.1 Degenerate Curve Removal and Generation
  • 4.2 Degenerate Curve Reconnection
  • 4.3 Transition Point Pair Cancellation and Generation
  • 4.4 Transition Point Relocation
  • 5 Conclusion
  • References
  • Continuous Histograms for Anisotropy of 2D Symmetric Piece-Wise Linear Tensor Fields
  • 1 Introduction
  • 2 Context and Related Work
  • 2.1 Continuous Histograms
  • 2.2 Notes on Tensor Field Interpolation
  • 2.3 Contour Trees, a Topological Summary of Scalar Functions
  • 3 Problem Statement and Solution Overview
  • 4 Background and Notations
  • 4.1 Second Order Symmetric Tensors and Anisotropy
  • 4.2 Barycentric Coordinates and Piece-Wise Linear Interpolation
  • 4.3 Bivariate Quadratic Functions and Their Critical Points
  • 5 Anisotropy for 2D Piece-Wise Linear Tensor Fields
  • 5.1 Field Normalization Using Coordinate Transformations
  • 6 Subdivision in Monotonous Sub-triangles
  • 7 Computation of the Histogram for ν
  • 7.1 Implementation
  • 8 Results
  • 8.1 Synthetic Data
  • 8.2 Simulation Data.
  • 8.3 Measurement Data
  • 9 Conclusions
  • References
  • Image Processing and Visualization
  • Tensor Approximation for Multidimensional and Multivariate Data
  • 1 Introduction
  • 1.1 Higher-Order Data Decompositions
  • 1.2 TA Applications in Graphics and Visualization
  • 1.3 Motivation and Contributions
  • 2 Singular Value Decomposition
  • 3 Tensor Approximation Notation and Definitions
  • 3.1 General Notation
  • 3.2 Computing with Tensors
  • 3.3 Rank of a Tensor
  • 4 Tensor Decompositions
  • 4.1 Tucker Model
  • 5 Tensor Rank Reduction
  • 5.1 Rank-R and Rank-(R1, R2, …, RN) Approximations
  • 5.2 Truncated Tensor Decomposition
  • 6 Tucker Decomposition Algorithms
  • 7 Tensor Reconstruction
  • 7.1 Element-Wise Reconstruction
  • 7.2 Optimized Tucker Reconstruction
  • 8 Useful TA Properties for Scientific Visualization
  • 8.1 Spatial Selectivity and Subsampling
  • 8.2 Approximation and Rank Reduction
  • 9 Application to Multivariate Data
  • 9.1 Dataset
  • 9.2 Vector Field Magnitude and Angle
  • 9.3 Vorticity and Divergence
  • 10 Conclusions
  • References
  • Fourth-Order Anisotropic Diffusion for Inpainting and Image Compression
  • 1 Introduction
  • 2 Background and Related Work
  • 2.1 Diffusion-Based Inpainting
  • 2.2 From Linear to Anisotropic Nonlinear Diffusion
  • 2.3 From Second to Fourth Order Diffusion
  • 2.4 Alternative Approaches to Image Compression
  • 3 Method
  • 3.1 Anisotropic Edge-Enhancing Fourth Order PDE
  • 3.2 A Unifying Framework for Fourth-Order Diffusion
  • 3.3 Discretization and Stability
  • 4 Experimental Results
  • 4.1 Reconstruction From a Sparse Set of Pixels
  • 4.2 Scratch Removal
  • 4.3 Effect of Diffusivity Function and Contrast Parameter
  • 5 Conclusions
  • References
  • Uncertainty in the DTI Visualization Pipeline
  • 1 Introduction
  • 2 Background
  • 2.1 Diffusion Tensor
  • 2.2 Fiber Tracking
  • 3 Sources of Uncertainty.
  • 3.1 Image Acquisition
  • 3.2 Diffusion Tensor Calculation
  • 3.3 Fiber Tracking
  • 3.4 Visualization
  • 4 Uncertainty Modeling
  • 4.1 Analytical Methods
  • 4.2 Stochastic Methods
  • 5 Uncertainty Visualization
  • 5.1 Local Uncertainty Visualization
  • 5.2 Global Uncertainty Visualization
  • 6 Conclusion
  • References
  • Challenges for Tractogram Filtering
  • 1 Introduction
  • 2 Approaches for Tractogram Filtering
  • 2.1 Explainability of the Diffusion Signal
  • 2.2 Inclusion and Exclusion ROIs
  • 2.3 Streamline Geometry or Shape
  • 2.4 Streamline Similarity and Clustering
  • 2.5 Multiapproaches
  • 3 Challenges and Perspective
  • 4 Conclusion
  • References
  • Modeling Anisotropy
  • Single Encoding Diffusion MRI: A Probe to Brain Anisotropy
  • 1 Accessing Brain Anisotropy Using Diffusion MRI
  • 1.1 Introduction
  • 1.2 Anisotropy as Reflected by Water Motion
  • 1.3 Structural Brain Anisotropy
  • 1.4 Measuring Anisotropy Using Diffusion MRI
  • 2 Diffusion MRI: Introduction to a Non-Invasive Imaging Technique
  • 2.1 Diffusion MRI Acquisition Sequence
  • 2.2 Mathematical Foundations
  • 2.3 Acquisition Strategies
  • 2.4 Difficulties
  • 3 Quantifying Anisotropy via Signal Representation
  • 3.1 Cumulant Expansion
  • 3.2 Other Representations
  • 3.3 Limitations
  • 4 Biophysical Modeling to Measure Anisotropy
  • 4.1 Multi-compartmental Model
  • 4.2 Neurites as Sticks
  • 4.3 Standard Model of Diffusion in Neural Tissue
  • 4.4 Standard Model Parameter Estimation Using Constraints
  • 4.5 Lemonade
  • 5 Summary and Above
  • References
  • Conceptual Parallels Between Stochastic Geometry and Diffusion-Weighted MRI
  • 1 Introduction
  • 2 Specific Volumes and the Short-Time Limit
  • 3 Stationarity and the Long-Time Limit
  • 4 Directional Measures and the Strong-Gradient Limit
  • 5 Perspectives
  • References.
  • Magnetic Resonance Assessment of Effective Confinement Anisotropy with Orientationally-Averaged Single and Double Diffusion Encoding
  • 1 Introduction
  • 2 Double Diffusion Encoding at the Compartment Level
  • 3 Double Diffusion Encoding: Powder Average
  • 3.1 Axisymmetric Confinement
  • 3.2 Insights from Two Dimensions
  • 3.3 One-Dimensional Diffusion Under High Gradient: g-2 Scaling
  • 4 Single Diffusion Encoding
  • 4.1 Axisymmetry and the Power-Laws for Confined diffusion
  • 5 Discussion
  • 6 Conclusion
  • References
  • Riemann-DTI Geodesic Tractography Revisited
  • 1 Introduction
  • 2 Theory
  • 3 Experiments
  • 4 Conclusion and Discussion
  • References
  • Measuring Anisotropy
  • Magnetic Resonance Imaging of T2- and Diffusion Anisotropy Using a Tiltable Receive Coil
  • 1 Introduction
  • 1.1 Background
  • 1.2 Scope of This Work
  • 2 Methods
  • 2.1 Data Acquisition
  • 2.2 MRI Signal Processing
  • 2.3 Estimation
  • 3 Results
  • 4 Discussion
  • 4.1 Incorporating Tiltable Coil in -diffusion correlation experiments
  • 4.2 Origin of -Contrast and -Anisotropy in WM
  • 4.3 Considerations in Data Processing
  • 5 Conclusion
  • References
  • Anisotropy in the Human Placenta in Pregnancies Complicated by Fetal Growth Restriction
  • 1 Introduction
  • 1.1 Placental Microstructure
  • 1.2 Placental MRI
  • 2 Methods
  • 2.1 Recruitment
  • 3 Results
  • 4 Discussion and Conclusion
  • References
  • Index.