English
Related papers

Related papers: Constructing Merger Trees of Density Peaks Using P…

200 papers

We propose a cell segmentation method for analyzing images of densely clustered cells. The method combines the strengths of marker-controlled watershed transformation and a convolutional neural network (CNN). We demonstrate the method…

Image and Video Processing · Electrical Eng. & Systems 2020-04-06 Filip Lux , Petr Matula

Throughout cosmological simulations, the properties of the matter density field in the initial conditions have a decisive impact on the features of the structures formed today. In this paper we use a random-forest classification algorithm…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-20 Jazhiel Chacón , J. Alberto Vázquez , Erick Almaraz

This paper presents an efficient method to perform Structured Matrix Approximation by Separation and Hierarchy (SMASH), when the original dense matrix is associated with a kernel function. Given points in a domain, a tree structure is first…

Numerical Analysis · Mathematics 2017-05-17 Difeng Cai , Edmond Chow , Yousef Saad , Yuanzhe Xi

Halo merger trees describe the hierarchical mass assembly of dark matter haloes, and are the backbone for modeling galaxy formation and evolution. Merger trees constructed using Monte Carlo algorithms based on the extended Press-Schechter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Fangzhou Jiang , Frank C. van den Bosch

Density level sets can be estimated using plug-in methods, excess mass algorithms or a hybrid of the two previous methodologies. The plug-in algorithms are based on replacing the unknown density by some nonparametric estimator, usually the…

Statistics Theory · Mathematics 2016-11-26 A. Rodríguez-Casal , P. Saavedra-Nieves

Particle-in-cell merging algorithms aim to resample dynamically the six-dimensional phase space occupied by particles without distorting substantially the physical description of the system. Whereas various approaches have been proposed in…

Plasma Physics · Physics 2015-11-16 Marija Vranic , Thomas Grismayer , Joana L. Martins , Ricardo A. Fonseca , Luis O. Silva

Data analysis in high-dimensional spaces aims at obtaining a synthetic description of a data set, revealing its main structure and its salient features. We here introduce an approach providing this description in the form of a topography of…

Machine Learning · Statistics 2021-03-02 Maria d'Errico , Elena Facco , Alessandro Laio , Alex Rodriguez

This article explores in depth a watershed concept to partition the universe, introduced in \cite{2019MNRAS.489L...1D} and applied to the {\it Cosmicflows-3} observational dataset. We present a series of tests conducted with cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 A. Dupuy , H. M. Courtois , N. Libeskind , D. Guinet

The cosmic web plays a major role in the formation and evolution of galaxies and defines, to a large extent, their properties. However, the relation between galaxies and environment is still not well understood. Here we present a machine…

Astrophysics of Galaxies · Physics 2018-04-11 Jianan Hui , Miguel A. Aragon-Calvo , Xinping Cui , James M. Flegal

Obtaining reliable permeability maps of oil reservoirs is crucial for building a robust and accurate reservoir simulation model and, therefore, designing effective recovery strategies. This problem, however, remains challenging, as it…

Tracking in high density environments plays an important role in many physics analyses at the LHC. In such environments, it is possible that two nearly collinear particles contribute to the same hits as they travel through the ATLAS pixel…

High Energy Physics - Experiment · Physics 2019-10-23 Patrick McCormack , Milan Ganai , Ben Nachman , Maurice Garcia-Sciveres

Merger trees harvested from cosmological $N$-body simulations encode the assembly histories of dark matter halos over cosmic time, and are a fundamental component of semi-analytical models (SAMs) of galaxy formation. The ability to compare…

Astrophysics of Galaxies · Physics 2019-02-20 Rhys J. J. Poulton , Aaron S. G. Robotham , Chris Power , Pascal J. Elahi

An improved implementation of an N-body code for simulating collisionless cosmological dynamics is presented. TPM (Tree-Particle-Mesh) combines the PM method on large scales with a tree code to handle particle-particle interactions at small…

Astrophysics · Physics 2009-11-07 Paul Bode , Jeremiah P. Ostriker

The description of complex configuration is a difficult issue. We present a powerful technique for cluster identification and characterization. The scheme is designed to treat with and analyze the experimental and/or simulation data from…

Statistical Mechanics · Physics 2013-08-29 Guangcai Zhang , Aiguo Xu , Guo Lu , Zeyao Mo

Precision mapping of landslide inventory is crucial for hazard mitigation. Most landslides generally co-exist with other confusing geological features, and the presence of such areas can only be inferred unambiguously at a large scale. In…

Image and Video Processing · Electrical Eng. & Systems 2020-02-21 Qing Zhu , Lin Chen , Han Hu , Binzhi Xu , Yeting Zhang , Haifeng Li

Upon a matrix representation of a binary bipartite network, via the permutation invariance, a coupling geometry is computed to approximate the minimum energy macrostate of a network's system. Such a macrostate is supposed to constitute the…

Applications · Statistics 2018-02-02 Jiahui Guan , Hsieh Fushing

This paper describes a framework for capturing geological structures in a 3D block model and improving its spatial fidelity given new mesh surfaces. Using surfaces that represent geological boundaries, the objectives are to identify areas…

Computational Engineering, Finance, and Science · Computer Science 2020-12-24 Raymond Leung

We propose a multi-phase approach to explore network structures. In this method, structure analysis is not carried out on the observed network directly. Instead, certain similarity measures of the nodes are derived from the network firstly,…

Physics and Society · Physics 2009-07-03 Xiaofeng Gong , Shuguang Guan , C. -H. Lai

The watershed is a powerful tool for segmenting objects whose contours appear as crest lines on a gradient image. The watershed transform associates to a topographic surface a partition into catchment basins, defined as attraction zones of…

Computer Vision and Pattern Recognition · Computer Science 2012-04-11 Fernand Meyer

Learned boundary maps are known to outperform hand- crafted ones as a basis for the watershed algorithm. We show, for the first time, how to train watershed computation jointly with boundary map prediction. The estimator for the merging…

Computer Vision and Pattern Recognition · Computer Science 2017-09-05 Steffen Wolf , Lukas Schott , Ullrich Köthe , Fred Hamprecht