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Unsupervised feature selection (UFS) is an important task in data engineering. However, most UFS methods construct models from a single perspective and often fail to simultaneously evaluate feature importance and preserve their inherent…

Machine Learning · Computer Science 2025-05-28 Jingjing Liu , Xiansen Ju , Xianchao Xiu , Wanquan Liu

A noise-based non-parametric technique for detecting nebulous objects, for example, irregular or clumpy galaxies, and their structure in noise is introduced. "Noise-based" and "non-parametric" imply that this technique imposes negligible…

Instrumentation and Methods for Astrophysics · Physics 2015-09-08 Mohammad Akhlaghi , Takashi Ichikawa

The greatest challenge in the interpretation of galaxy clustering data from any surveys is galaxy bias. Using a simple Fisher matrix analysis, we show that the bispectrum provides an excellent determination of linear and non-linear bias…

Astrophysics · Physics 2008-11-26 Emiliano Sefusatti , Eiichiro Komatsu

Image classification is a challenging problem for computer in reality. Large numbers of methods can achieve satisfying performances with sufficient labeled images. However, labeled images are still highly limited for certain image…

Computer Vision and Pattern Recognition · Computer Science 2020-11-12 Hongfeng Li

This paper investigates the problem of image classification with limited or no annotations, but abundant unlabeled data. The setting exists in many tasks such as semi-supervised image classification, image clustering, and image retrieval.…

Computer Vision and Pattern Recognition · Computer Science 2016-02-05 Dengxin Dai , Luc Van Gool

The information recoverable from galaxy spectra depends fundamentally on spectral resolution, yet assembling large samples at high resolution remains observationally expensive. We present a deep-learning framework for spectral…

Single-particle cryo-electron microscopy (cryo-EM) is a leading technology to resolve the structure of molecules. Early in the process, the user detects potential particle images in the raw data. Typically, there are many false detections…

Image and Video Processing · Electrical Eng. & Systems 2023-03-08 Gili Weiss-Dicker , Amitay Eldar , Yoel Shkolinsky , Tamir Bendory

Regression mixture models are widely studied in statistics, machine learning and data analysis. Fitting regression mixtures is challenging and is usually performed by maximum likelihood by using the expectation-maximization (EM) algorithm.…

Methodology · Statistics 2014-09-25 Faicel Chamroukhi

This paper is aimed at developing a better understanding of the structure of the information that in contained in galaxy surveys, so as to find optimal ways to combine observables from such surveys. We first show how Jaynes' Maximal Entropy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Julien Carron , Adam Amara , Simon Lilly

For high-dimensional classification, it is well known that naively performing the Fisher discriminant rule leads to poor results due to diverging spectra and noise accumulation. Therefore, researchers proposed independence rules to…

Machine Learning · Statistics 2011-11-10 Jianqing Fan , Yang Feng , Xin Tong

In Stage-IV imaging surveys, a significant amount of the cosmologically useful information is due to sources whose images overlap with those of other sources on the sky. The cosmic shear signal is primarily encoded in the estimated shapes…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Javier Sanchez , Ismael Mendoza , David P. Kirkby , Patricia R. Burchat

We develop a Maximum Likelihood estimator (MLE) to measure the masses of galaxy clusters through the impact of gravitational lensing on the temperature and polarization anisotropies of the cosmic microwave background (CMB). We show that, at…

The expectation-maximization (EM) algorithm is an iterative computational method to calculate the maximum likelihood estimators (MLEs) from the sample data. It converts a complicated one-time calculation for the MLE of the incomplete data…

Computation · Statistics 2016-08-08 Lingyao Meng

This study introduces a general semiparametric clusterwise index distribution model to analyze how latent clusters affect the covariate-response relationships. By employing sufficient dimension reduction to account for the effects of…

Methodology · Statistics 2025-09-30 Jen-Chieh Teng , Chin-Tsang Chiang

Through spectral unmixing, hyperspectral imaging (HSI) in fluorescence-guided brain tumor surgery has enabled detection and classification of tumor regions invisible to the human eye. Prior unmixing work has focused on determining a minimal…

Image and Video Processing · Electrical Eng. & Systems 2024-02-01 David Black , Benoit Liquet , Sadahiro Kaneko , Antonio Di leva , Walter Stummer , Eric Suero Molina

Cluster analysis is a widely applied machine learning technique to understand the existing patterns in the population of gamma-ray bursts (GRBs), in order to explore their physical sources. In the present scenario, the number of clusters…

High Energy Astrophysical Phenomena · Physics 2026-05-29 Soumita Modak

Semi-supervised learning methods are usually employed in the classification of data sets where only a small subset of the data items is labeled. In these scenarios, label noise is a crucial issue, since the noise may easily spread to a…

Machine Learning · Computer Science 2020-02-14 Fabricio Aparecido Breve , Liang Zhao , Marcos Gonçalves Quiles

Unsupervised learning algorithms are beginning to achieve accuracies comparable to their supervised counterparts on benchmark computer vision tasks, but their utility for practical applications has not yet been demonstrated. In this work,…

Computer Vision and Pattern Recognition · Computer Science 2022-01-13 Jeremiah W. Johnson , Swathi Hari , Donald Hampton , Hyunju K. Connor , Amy Keesee

We make the first detailed MCMC likelihood study of cosmological constraints that are expected from some of the largest, ongoing and proposed, cluster surveys in different wave-bands and compare the estimates to the prevalent Fisher matrix…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-21 Satej Khedekar , Subhabrata Majumdar

Weak gravitational lensing measurements based on photometry are limited by shape noise, the variance in the unknown unlensed orientations of the source galaxies. If the source is a disk galaxy with a well-ordered velocity field, however,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-08 David Wittman , Matthew Self