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Stars form in dense, dusty clumps of molecular clouds, but little is known about their origin and evolution. In particular, the relationship between the mass distribution of these clumps (also known as the "clump mass function", or CMF) and…

We use numerical simulations of turbulent cluster-forming regions to study the nature of dense filamentary structures in star formation. Using four hydrodynamic and magnetohydrodynamic simulations chosen to match observations, we identify…

Astrophysics of Galaxies · Physics 2015-06-23 Helen Kirk , Ralph Pudritz , Mikhail Klassen , Samantha Pillsworth

The fragmentation of shocked flows in a thermally bistable medium provides a natural mechanism to form turbulent cold clouds as precursors to molecular clouds. Yet because of the large density and temperature differences and the range of…

Astrophysics of Galaxies · Physics 2015-05-27 Fabian Heitsch , Thorsten Naab , Stefanie Walch

This paper proposes a novel framework for the approximation and analysis of circular density data using compositional periodic splines within Bayes spaces with the Hilbert space structure. By applying the centered log-ratio transformation,…

Methodology · Statistics 2026-05-19 Jitka Machalová , Jana Heckenbergerová , Karel Hron

A probability density function (pdf) encodes the entire stochastic knowledge about data distribution, where data may represent stochastic observations in robotics, transition state pairs in reinforcement learning or any other empirically…

Machine Learning · Computer Science 2018-09-18 Dmitry Kopitkov , Vadim Indelman

We present a general framework to treat the evolution of one-point probability distribution function (PDF) for cosmic density $\delta$ and velocity-divergence fields $\theta$. In particular, we derive an evolution equation for the one-point…

Astrophysics · Physics 2009-11-07 Yasuhiro Ohta , Issha Kayo , Atsushi Taruya

Granular column collapse is a simple but important problem to the granular material community, due to its links to dynamics of natural hazards, such as landslides and pyroclastic flows, and many industrial situations, as well as its…

Soft Condensed Matter · Physics 2025-01-10 Teng Man , Herbert E. Huppert , Sergio Andres Galindo-Torres

Given a sample of independent and identically distributed random variables, a novel nonparametric maximum entropy method is presented to estimate the underlying continuous univariate probability density function (pdf). Estimates are found…

Probability · Mathematics 2016-06-30 Jenny Farmer , Donald J. Jacobs

Existing point cloud semantic segmentation networks cannot identify unknown classes and update their knowledge, due to a closed-set and static perspective of the real world, which would induce the intelligent agent to make bad decisions. To…

Computer Vision and Pattern Recognition · Computer Science 2024-07-24 Jinfeng Xu , Siyuan Yang , Xianzhi Li , Yuan Tang , Yixue Hao , Long Hu , Min Chen

We present an analysis of probability distribution functions (pdfs) of column density in different zones of the star-forming region Perseus and its diffuse environment based on the map of dust opacity at 353 GHz available from the Planck…

Astrophysics of Galaxies · Physics 2015-08-06 Orlin Stanchev , Todor V. Veltchev , Jens Kauffmann , Sava Donkov , Rahul Shetty , Bastian Körtgen , Ralf S. Klessen

The amount, size, and complexity of astronomical data-sets and databases are growing rapidly in the last decades, due to new technologies and dedicated survey telescopes. Besides dealing with poly-structured and complex data, sparse data…

Instrumentation and Methods for Astrophysics · Physics 2021-03-08 Kai Lars Polsterer , Antonio D'Isanto , Sebastian Lerch

Turbulence is a mysterious phenomenon in physical systems and plays a critical role in the interstellar medium (ISM). Previous simulations and observations have shown that the probability density functions (PDFs) of gas densities in…

Astrophysics of Galaxies · Physics 2025-03-26 Xunchuan Liu

In probability density function (PDF) methods of turbulent flows, the joint PDF of several flow variables is computed by numerically integrating a system of stochastic differential equations for Lagrangian particles. A mathematically exact…

Fluid Dynamics · Physics 2010-06-17 J. Bakosi

We present new high resolution and dynamic range dust column density and temperature maps of the California Molecular Cloud derived from a combination of Planck and Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. We used…

Astrophysics of Galaxies · Physics 2017-10-25 Charles J. Lada , John A. Lewis , Marco Lombardi , João Alves

A new approach is presented to obtain candidate structures from atomic pair distribution function (PDF) data in a highly automated way. It fetches, from web-based structural databases, all the structures meeting the experimenter's search…

Materials Science · Physics 2020-05-07 Long Yang , Pavol Juhás , Maxwell W. Terban , Matthew G. Tucker , Simon J. L. Billinge

Star formation has long been known to be an inefficient process, in the sense that only a small fraction $\epsilon_{\rm ff}$ of the mass of any given gas cloud is converted to stars per cloud free-fall time. However, developing a successful…

Astrophysics of Galaxies · Physics 2021-02-17 Zipeng Hu , Mark R. Krumholz , Christoph Federrath , Riwaj Pokhrel , Robert A. Gutermuth

Although there are a wealth of column density tracers for both the molecular and diffuse interstellar medium, there are very few observational studies investigating the relationship between the density variance ($\sigma^2$) and the sonic…

Astrophysics of Galaxies · Physics 2015-06-05 Blakesley Burkhart , A. Lazarian

We study two limiting cases of turbulence forcing in numerical experiments: solenoidal (divergence-free) forcing, and compressive (curl-free) forcing, and compare our results to observations reported in the literature. We solve the…

Solar and Stellar Astrophysics · Physics 2010-07-16 C. Federrath , J. Roman-Duval , R. Klessen , W. Schmidt , M. -M. Mac Low

Volumetry is one of the principal downstream applications of 3D medical image segmentation, for example, to detect abnormal tissue growth or for surgery planning. Conformal Prediction is a promising framework for uncertainty quantification,…

Computer Vision and Pattern Recognition · Computer Science 2024-07-30 Benjamin Lambert , Florence Forbes , Senan Doyle , Michel Dojat

Stochastic simulation methods can be applied successfully to model exact spatio-temporally resolved reaction-diffusion systems. However, in many cases, these methods can quickly become extremely computationally intensive with increasing…

Quantitative Methods · Quantitative Biology 2016-04-29 Jonathan U. Harrison , Christian A. Yates