Inverse problems | Mathematical analysis
Spectral regularization is any of a class of regularization techniques used in machine learning to control the impact of noise and prevent overfitting. Spectral regularization can be used in a broad range of applications, from deblurring images to classifying emails into a spam folder and a non-spam folder. For instance, in the email classification example, spectral regularization can be used to reduce the impact of noise and prevent overfitting when a machine learning system is being trained on a labeled set of emails to learn how to tell a spam and a non-spam email apart. Spectral regularization algorithms rely on methods that were originally defined and studied in the theory of ill-posed inverse problems (for instance, see) focusing on the inversion of a linear operator (or a matrix) that possibly has a bad condition number or an unbounded inverse. In this context, regularization amounts to substituting the original operator by a bounded operator called the "regularization operator" that has a condition number controlled by a regularization parameter, a classical example being Tikhonov regularization. To ensure stability, this regularization parameter is tuned based on the level of noise. The main idea behind spectral regularization is that each regularization operator can be described using spectral calculus as an appropriate filter on the eigenvalues of the operator that defines the problem, and the role of the filter is to "suppress the oscillatory behavior corresponding to small eigenvalues". Therefore, each algorithm in the class of spectral regularization algorithms is defined by a suitable filter function (which needs to be derived for that particular algorithm). Three of the most commonly used regularization algorithms for which spectral filtering is well-studied are Tikhonov regularization, Landweber iteration, and truncated singular value decomposition (TSVD). As for choosing the regularization parameter, examples of candidate methods to compute this parameter include the discrepancy principle, generalized cross validation, and the L-curve criterion. It is of note that the notion of spectral filtering studied in the context of machine learning is closely connected to the literature on function approximation (in signal processing). (Wikipedia).
Network Analysis. Lecture 9. Graph partitioning algorithms
Graph density. Graph pertitioning. Min cut, ratio cut, normalized and quotient cuts metrics. Spectral graph partitioning (normalized cut). Direct (spectral) modularity maximization. Multilevel recursive partitioning Lecture slides: http://www.leonidzhukov.net/hse/2015/networks/lectures/le
From playlist Structural Analysis and Visualization of Networks.
reaLD 3D glasses filter with a linear polarising filter
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From playlist Everything in chronological order
2020.05.21 Sara van der Geer - Learning with total variation regularization
Consider the classical problem of learning a signal when observed with noise. One way to do this is to expand the signal in terms of basis functions and then try to learn the coefficients. The collection of basis functions is called a dictionary and the approach is sometimes called "synthe
From playlist One World Probability Seminar
Introduction to Frequency Selective Filtering
http://AllSignalProcessing.com for free e-book on frequency relationships and more great signal processing content, including concept/screenshot files, quizzes, MATLAB and data files. Separation of signals based on frequency content using lowpass, highpass, bandpass, etc filters. Filter g
From playlist Introduction to Filter Design
Gilles Pagès: Optimal vector Quantization: from signal processing to clustering and ...
Abstract: Optimal vector quantization has been originally introduced in Signal processing as a discretization method of random signals, leading to an optimal trade-off between the speed of transmission and the quality of the transmitted signal. In machine learning, similar methods applied
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I discuss causal and non-causal noise filters: the moving average filter and the exponentially weighted moving average. I show how to do this filtering in Excel and Python
From playlist Discrete
Eighth Imaging & Inverse Problems (IMAGINE) OneWorld SIAM-IS Virtual Seminar Series Talk
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From playlist Imaging & Inverse Problems (IMAGINE) OneWorld SIAM-IS Virtual Seminar Series
Lecture 3: Single-shot Multi-domain Camera
MIT MAS.531 Computational Camera and Photography, Fall 2009 Instructor: Roarke Horstmeyer View the complete course: https://ocw.mit.edu/courses/mas-531-computational-camera-and-photography-fall-2009/ YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP61pwA6paIRZ30q1sjLE8b6
From playlist MIT MAS.531 Computational Camera and Photography, Fall 2009
12: Spectral Analysis Part 2 - Intro to Neural Computation
MIT 9.40 Introduction to Neural Computation, Spring 2018 Instructor: Michale Fee View the complete course: https://ocw.mit.edu/9-40S18 YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP61I4aI5T6OaFfRK2gihjiMm Covers Fourier transform pairs and power spectra, spectral esti
From playlist MIT 9.40 Introduction to Neural Computation, Spring 2018
Fabio Cipriani: Spectral densities and hypertrace in NCG
Talk in Global Noncommutative Geometry Seminar (Europe). 18 May 2022
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Jeremy Hahn : Prismatic and syntomic cohomology of ring spectra
CONFERENCE Recording during the thematic meeting : « Chromatic Homotopy, K-Theory and Functors» the January 24, 2023 at the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Jean Petit Find this video and other talks given by worldwide mathematicians on CIR
From playlist Topology
AMMI Course "Geometric Deep Learning" - Lecture 8 (Groups & Homogeneous spaces) - Taco Cohen
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Optimal machine learning with stochastic projections (...) - Rosasco - Workshop 3 - CEB T1 2019
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From playlist 2019 - T1 - The Mathematics of Imaging
Can You Solve This Astronomical Riddle?
In this video we look at one of the greatest astronomy riddles in history. A special thank you to Dr. Christian Sasse for all your help with this video, as well as the people of Siding Spring Observatory who made my time there so pleasant. If you'd like to learn how to make your own sp
From playlist Physics
Frequency Domain Interpretation of Sampling
http://AllSignalProcessing.com for more great signal-processing content: ad-free videos, concept/screenshot files, quizzes, MATLAB and data files. Analysis of the effect of sampling a continuous-time signal in the frequency domain through use of the Fourier transform.
From playlist Sampling and Reconstruction of Signals
Xavier Bresson: "Convolutional Neural Networks on Graphs"
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