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Related papers: Regularity in the distribution of superclusters?

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An automatic procedure to perform sub-clustering on large samples is presented. At each iteration, the most diverse cluster is sub-clustered, and the global diversity of the new classification is compared to the previous one. The process…

Instrumentation and Methods for Astrophysics · Physics 2025-05-15 Hugo Chambon , Didier Fraix-Burnet

Nonparametric Bayesian approaches provide a flexible framework for clustering without pre-specifying the number of groups, yet they are well known to overestimate the number of clusters, especially for functional data. We show that a…

Methodology · Statistics 2025-10-21 Fumiya Iwashige , Tomoya Wakayama , Shonosuke Sugasawa , Shintaro Hashimoto

Spectral clustering requires the time-consuming decomposition of the Laplacian matrix of the similarity graph, thus limiting its applicability to large datasets. To improve the efficiency of spectral clustering, a top-down approach was…

Machine Learning · Computer Science 2024-12-19 Zhichang Xu , Zhiguo Long , Hua Meng

Data clustering is the process of identifying natural groupings or clusters within multidimensional data based on some similarity measure. Clustering is a fundamental process in many different disciplines. Hence, researchers from different…

Machine Learning · Computer Science 2014-08-26 Sibei Yang , Liangde Tao , Bingchen Gong

Substructure in galaxy clusters can be quantified with the robust Delta statistics (Dressler and Shectman 1988) which uses velocity kinematics and sky projected positions. We test its sensitivity using dissipationless numerical simulations…

Astrophysics · Physics 2007-05-23 Alexander Knebe , Volker Mueller

Based on an expert systems approach, the issue of community detection can be conceptualized as a clustering model for networks. Building upon this further, community structure can be measured through a clustering coefficient, which is…

Social and Information Networks · Computer Science 2019-04-12 Roy Cerqueti , Giovanna Ferraro , Antonio Iovanella

We analyse the dependence of clustering properties of galaxies as a function of their large-scale environment. In order to characterize the environment on large scales, we use the catalogue of future virialized superstructures (FVS) by…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-30 C. Yamila Yaryura , Marcelo Lares , Heliana E. Luparello , Dante J. Paz , Diego G. Lambas , Nelson Padilla , Mario A. Sgró

Clustering in image analysis is a central technique that allows to classify elements of an image. We describe a simple clustering technique that uses the method of similarity matrices. We expand upon recent results in spectral analysis for…

Statistics Theory · Mathematics 2022-03-23 Denis Gaidashev , Ralf Pihlström , Martin Ryner

Biclustering involves the simultaneous clustering of objects and their attributes, thus defining local two-way clustering models. Recently, efficient algorithms were conceived to enumerate all biclusters in real-valued datasets. In this…

Machine Learning · Computer Science 2015-06-04 Saullo Haniell Galvão de Oliveira , Rosana Veroneze , Fernando José Von Zuben

We develop a network in which the natural numbers are the vertices. We use the decomposition of natural numbers by prime numbers to establish the connections. We perform data collapse and show that the degree distribution of these networks…

Statistical Mechanics · Physics 2009-11-10 Gilberto Corso

The analysis of the presence of substructures in 16 well-sampled clusters of galaxies suggests a stimulating hypothesis: Clusters could be classified as unimodal or bimodal, on the basis of to the sub-clump distribution in the {\em 3-D}…

Astrophysics · Physics 2009-10-22 E. Escalera , A. Biviano , M. Girardi , G. Giuricin , F. Mardirossian , A. Mazure , M. Mezzetti

Stars form predominantly in groups usually denoted as clusters or associations. The observed stellar groups display a broad spectrum of masses, sizes and other properties, so it is often assumed that there is no underlying structure in this…

Solar and Stellar Astrophysics · Physics 2016-02-03 S. Pfalzner , H. Kirk , A. Sills , J. S. Urquhart , J. Kauffmann , M. A. Kuhn , A. Bhandare , K. M. Menten

Clusters of galaxies are often embedded in larger-scale superclusters with dimensions of tens or perhaps even hundreds of Mpc. Observational and theoretical evidence suggest an important connection between cluster properties and their…

Astrophysics · Physics 2009-09-25 Michael J. West

Traditionally, the Dirichlet-multinomial distribution has been recognized as a key model for contingency tables generated by cluster sampling schemes. There are, however, other possible distributions appropriate for these contingency…

Methodology · Statistics 2016-09-26 Juana M. Alonso-Revenga , Nirian Martin , Leandro Pardo

An unsupervised classification method for point events occurring on a network of lines is proposed. The idea relies on the distributional flexibility and practicality of random partition models to discover the clustering structure featuring…

In an age of increasingly large data sets, investigators in many different disciplines have turned to clustering as a tool for data analysis and exploration. Existing clustering methods, however, typically depend on several nontrivial…

Quantitative Methods · Quantitative Biology 2009-11-11 Noam Slonim , Gurinder Singh Atwal , Gasper Tkacik , William Bialek

While clustering is ubiquitously used across science and industry, uncertainty in cluster assignments is rarely quantified with rigorous guarantees. We propose a novel conformal inference framework for clustering that returns confidence…

Methodology · Statistics 2026-04-13 YoonHaeng Hur , Anirban Nath , Genevera Allen

Satellites within simulated massive clusters are significantly spatially correlated with each other, even when those satellites are not gravitationally bound to each other. This correlation is produced by satellites that entered their hosts…

Astrophysics of Galaxies · Physics 2014-07-11 Robert T. Chamberlain , Neal Dalal , Andrew Hearin , Paul Ricker

The statistical behavior of the size (or mass) of the largest cluster in subcritical percolation on a finite lattice of size $N$ is investigated (below the upper critical dimension, presumably $d_c=6$). It is argued that as $N \to \infty$…

Statistical Mechanics · Physics 2009-10-31 Martin Z. Bazant

The consistency of the maximum likelihood estimator for mixtures of elliptically-symmetric distributions for estimating its population version is shown, where the underlying distribution $P$ is nonparametric and does not necessarily belong…

Statistics Theory · Mathematics 2024-10-14 Pietro Coretto , Christian Hennig