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In medical image segmentation, limited external validity remains a critical obstacle when models are deployed across unseen datasets, an issue particularly pronounced in the ultrasound image domain. Existing solutions-such as domain…

Image and Video Processing · Electrical Eng. & Systems 2025-05-30 Christian Schmidt , Heinrich Martin Overhoff

We present a method to model optical images of galaxies using Expectation Maximization Principal Components Analysis (EMPCA). The method relies on the data alone and does not assume any pre-established model or fitting formula. It preserves…

Astrophysics of Galaxies · Physics 2017-08-16 Matteo Maturi

Retrieval-Augmented Generation (RAG) has emerged as a powerful paradigm for grounding large language models in external knowledge sources, improving the precision of agents responses. However, high-dimensional language model embeddings,…

Machine Learning · Computer Science 2025-04-14 Arman Khaledian , Amirreza Ghadiridehkordi , Nariman Khaledian

Principal Components Analysis (PCA) and Independent Component Analysis (ICA) are used to identify global patterns in solar and space data. PCA seeks orthogonal modes of the two-point correlation matrix constructed from a data set. It…

Astrophysics · Physics 2009-11-13 A. C. Cadavid , J. K. Lawrence , A. Ruzmaikin

In this paper, we propose a novel approach named by Discriminative Principal Component Analysis which is abbreviated as Discriminative PCA in order to enhance separability of PCA by Linear Discriminant Analysis (LDA). The proposed method…

Computer Vision and Pattern Recognition · Computer Science 2019-03-13 Hanli Qiao

Cryo-electron microscopy nowadays often requires the analysis of hundreds of thousands of 2D images as large as a few hundred pixels in each direction. Here we introduce an algorithm that efficiently and accurately performs principal…

Computer Vision and Pattern Recognition · Computer Science 2015-12-16 Zhizhen Zhao , Yoel Shkolnisky , Amit Singer

We demonstrate how galaxy morphologies can be represented by weighted sums of "eigengalaxies" and how eigengalaxies can be used in a probabilistic framework to enable principled and simplified approaches in a variety of applications.…

Astrophysics of Galaxies · Physics 2020-09-09 Emir Uzeirbegovic , James E. Geach , Sugata Kaviraj

Often the relation between the variables constituting a multivariate data space might be characterized by one or more of the terms: ``nonlinear'', ``branched'', ``disconnected'', ``bended'', ``curved'', ``heterogeneous'', or, more general,…

Astrophysics · Physics 2007-09-12 Jochen Einbeck , Ludger Evers , Coryn Bailer-Jones

Einstein rings are rare gem of the strong lensing phenomena. Unlike doubly or quadruply lensed systems, the ring images can be used to probe the underlying lens gravitational potential at every position angle, putting much tighter…

Astrophysics of Galaxies · Physics 2017-04-05 Chien-Hsiu Lee

We introduce the notion of Principal Component Analysis (PCA) of image gradient orientations. As image data is typically noisy, but noise is substantially different from Gaussian, traditional PCA of pixel intensities very often fails to…

Computer Vision and Pattern Recognition · Computer Science 2010-05-18 Georgios Tzimiropoulos , Stefanos Zafeiriou

Principal Component Analysis (PCA) is a widely utilized technique for dimensionality reduction; however, its inherent lack of interpretability-stemming from dense linear combinations of all feature-limits its applicability in many domains.…

Machine Learning · Computer Science 2025-04-01 Loc Hoang Tran

Three-dimensional (3D) spectroscopy techniques are becoming more and more popular, producing an increasing number of large data cubes. The challenge of extracting information from these cubes requires the development of new techniques for…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-28 T. V. Ricci , J. E. Steiner , R. B. Menezes

Principal component analysis (PCA) is one of the most fundamental tools in machine learning with broad use as a dimensionality reduction and denoising tool. In the later setting, while PCA is known to be effective at subspace recovery and…

Machine Learning · Computer Science 2024-04-23 Chandra Sekhar Mukherjee , Nikhil Doerkar , Jiapeng Zhang

We reconstruct late-time cosmology using the technique of Principal Component Analysis (PCA). In particular, we focus on the reconstruction of the dark energy equation of state from two different observational data-sets, Supernovae type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-07 Ranbir Sharma , Ankan Mukherjee , H. K. Jassal

The Laser Interferometer Space Antenna (LISA) will provide us with a unique opportunity to observe the early inspiral phase of supermassive binary black holes (SMBBHs) in the mass range of $10^5-10^6\,M_{\odot}$, that lasts for several…

General Relativity and Quantum Cosmology · Physics 2023-03-09 Sayantani Datta

Principal Component Analysis (PCA) is a workhorse of modern data science. While PCA assumes the data conforms to Euclidean geometry, for specific data types, such as hierarchical and cyclic data structures, other spaces are more…

Machine Learning · Statistics 2024-07-11 Puoya Tabaghi , Michael Khanzadeh , Yusu Wang , Sivash Mirarab

We demonstrate the use of a variant of Principal Component Analysis (PCA) for discrimination problems in astronomy. This variant of PCA is shown to provide the best linear discrimination between data classes. As a test case, we present the…

Astrophysics · Physics 2009-10-30 Rodrigo Ibata , Michael Irwin

Searching for departures from general relativity (GR) in more than one post-Newtonian (PN) phasing coefficients, called a \emph{multi-parameter test}, is known to be ineffective given the sensitivity of the present generation of…

General Relativity and Quantum Cosmology · Physics 2022-05-11 Muhammed Saleem , Sayantani Datta , K. G. Arun , B. S. Sathyaprakash

Principal Component Analysis (PCA) is the most widely used tool for linear dimensionality reduction and clustering. Still it is highly sensitive to outliers and does not scale well with respect to the number of data samples. Robust PCA…

Computer Vision and Pattern Recognition · Computer Science 2015-04-24 Nauman Shahid , Vassilis Kalofolias , Xavier Bresson , Michael Bronstein , Pierre Vandergheynst

Gravitational lensings provide unique opportunities to study distant galaxies. Despite their usefulness, only a dozens of gravitational arcs have been reported up-to-date, hampered by the low resolution imaging from ground-based surveys. We…

Instrumentation and Methods for Astrophysics · Physics 2017-11-10 Chien-Hsiu Lee