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Related papers: Classification of Stellar Spectra with LLE

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We introduce Locally Linear Embedding (LLE) to the astronomical community as a new classification technique, using SDSS spectra as an example data set. LLE is a nonlinear dimensionality reduction technique which has been studied in the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 J. T. VanderPlas , A. J. Connolly

We present the results of the application of locally linear embedding (LLE) to reduce the dimensionality of dereddened and continuum subtracted near-infrared spectra using a combination of models and real spectra of massive protostars…

Instrumentation and Methods for Astrophysics · Physics 2016-06-23 J. L. Ward , S. L. Lumsden

In this work, we select the high signal-to-noise ratio spectra of stars from the LAMOST data andmap theirMK classes to the spectral features. The equivalentwidths of the prominent spectral lines, playing the similar role as the multi-color…

Solar and Stellar Astrophysics · Physics 2015-05-25 Chao Liu , Wen-Yuan Cui , Bo Zhang , Jun-Chen Wan , Li-Cai Deng , Yonghui Hou , Yuefei Wang , Ming Yang , Yong Zhang

We present a new and effective approach for Hyperspectral Image (HSI) classification and clutter detection, overcoming a few long-standing challenges presented by HSI data characteristics. Residing in a high-dimensional spectral attribute…

Computer Vision and Pattern Recognition · Computer Science 2015-06-04 Alexandros-Stavros Iliopoulos , Tiancheng Liu , Xiaobai Sun

Due to the ever-expanding volume of observed spectroscopic data from surveys such as SDSS and LAMOST, it has become important to apply artificial intelligence (AI) techniques for analysing stellar spectra to solve spectral classification…

Solar and Stellar Astrophysics · Physics 2020-01-08 Kaushal Sharma , Ajit Kembhavi , Aniruddha Kembhavi , T. Sivarani , Sheelu Abraham , Kaustubh Vaghmare

Standard Adjacency Spectral Embedding (ASE) relies on a global low-rank assumption often incompatible with the sparse, transitive structure of real-world networks, causing local geometric features to be 'smeared'. To address this, we…

Machine Learning · Statistics 2026-03-13 Hannah Sansford , Nick Whiteley , Patrick Rubin-Delanchy

Large-scale and deep sky survey missions are rapidly collecting a large amount of stellar spectra, which necessitate the estimation of atmospheric parameters directly from spectra and makes it feasible to statistically investigate latent…

Solar and Stellar Astrophysics · Physics 2015-04-13 Xiangru Li , Q. M. Jonathan Wu , Ali Luo , Yongheng Zhao , Yu Lu , Fang Zuo , Tan Yang , Yongjun Wang

The spectral energy distribution (SED) of observed stars in wide-field images is crucial for chromatic point spread function (PSF) modelling methods, which use unresolved stars as integrated spectral samples of the PSF across the field of…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 Ezequiel Centofanti , Samuel Farrens , Jean-Luc Starck , Tobias Liaudat , Alex Szapiro , Jennifer Pollack

Local Linear embedding (LLE) is a popular dimension reduction method. In this paper, we first show LLE with nonnegative constraint is equivalent to the widely used Laplacian embedding. We further propose to iterate the two steps in LLE…

Machine Learning · Computer Science 2012-07-03 Deguang Kong , Chris H. Q. Ding , Heng Huang , Feiping Nie

Dimensionality reduction (DR) is characterized by two longstanding trade-offs. First, there is a global-local preservation tension: methods such as t-SNE and UMAP prioritize local neighborhood preservation, yet may distort global manifold…

Machine Learning · Computer Science 2026-04-06 Zeyang Huang , Angelos Chatzimparmpas , Thomas Höllt , Takanori Fujiwara

High resolution galaxy spectra contain much information about galactic physics, but the high dimensionality of these spectra makes it difficult to fully utilize the information they contain. We apply variational autoencoders (VAEs), a…

Instrumentation and Methods for Astrophysics · Physics 2020-07-13 Stephen K. N. Portillo , John K. Parejko , Jorge R. Vergara , Andrew J. Connolly

Information on the spectral types of stars is of great interest in view of the exploitation of space-based imaging surveys. In this article, we investigate the classification of stars into spectral types using only the shape of their…

Instrumentation and Methods for Astrophysics · Physics 2016-06-15 T. Kuntzer , M. Tewes , F. Courbin

We apply a novel spectral graph technique, that of locally-biased semi-supervised eigenvectors, to study the diversity of galaxies. This technique permits us to characterize empirically the natural variations in observed spectra data, and…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 David Lawlor , Tamás Budavári , Michael W. Mahoney

In recent years, hyperspectral imaging, also known as imaging spectroscopy, has been paid an increasing interest in geoscience and remote sensing community. Hyperspectral imagery is characterized by very rich spectral information, which…

Computer Vision and Pattern Recognition · Computer Science 2020-07-20 Danfeng Hong , Jing Yao , Xin Wu , Jocelyn Chanussot , Xiao Xiang Zhu

When dealing with continuous numeric features, we usually adopt feature discretization. In this work, to find the best way to conduct feature discretization, we present some theoretical analysis, in which we focus on analyzing correctness…

Machine Learning · Computer Science 2020-04-28 Qiang Liu , Zhaocheng Liu , Haoli Zhang

Recently, a variety of approaches has been enriching the field of Remote Sensing (RS) image processing and analysis. Unfortunately, existing methods remain limited faced to the rich spatio-spectral content of today's large datasets. It…

Computer Vision and Pattern Recognition · Computer Science 2018-08-15 Amina Ben Hamida , A Benoit , Patrick Lambert , Chokri Ben Amar

We present Stellar Locus Regression (SLR), a method of directly adjusting the instrumental broadband optical colors of stars to bring them into accord with a universal stellar color-color locus, producing accurately calibrated colors for…

Instrumentation and Methods for Astrophysics · Physics 2010-05-12 F. William High , Christopher W. Stubbs , Armin Rest , Brian Stalder , Peter Challis

Broad-band measurements of flux for galaxies at different redshifts measure different regions of the rest-frame galaxy spectrum. Certain astronomical questions, such as the evolution of the luminosity function of galaxies, require…

Beginning with a historical account of the spectral classification, its refinement through additional criteria is presented. The line strengths and ratios used in two dimensional classifications of each spectral class are described. A…

Solar and Stellar Astrophysics · Physics 2015-05-18 Sunetra Giridhar

The local linear embedding algorithm (LLE) is a non-linear dimension-reducing technique, widely used due to its computational simplicity and intuitive approach. LLE first linearly reconstructs each input point from its nearest neighbors and…

Machine Learning · Statistics 2008-08-07 Yair Goldberg , Ya'acov Ritov
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