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In this paper, the sensitivity analysis of a single scale model is employed in order to reduce the input dimensionality of the related multiscale model, in this way, improving the efficiency of its uncertainty estimation. The approach is…

Computation · Statistics 2019-11-12 Anna Nikishova , Giovanni E. Comi , Alfons G. Hoekstra

Databases of gas and surface chemical reactions are a key tool for scientists working in a wide range of physical sciences. In Astrochemistry, databases of chemical reactions are used as inputs to chemical models to determine the abundances…

Astrophysics of Galaxies · Physics 2021-01-14 Serena Viti , Jonathan Holdship

Energy systems modellers often resort to simplified system representations and deterministic model formulations (i.e., not considering uncertainty) to preserve computational tractability. However, reduced levels of detail and neglected…

Physics and Society · Physics 2022-08-18 Maria Yliruka , Stefano Moret , Nilay Shah

Although uncertainty quantification has been making its way into nuclear theory, these methods have yet to be explored in the context of reaction theory. For example, it is well known that different parameterizations of the optical…

Nuclear Theory · Physics 2017-03-01 A. E. Lovell , F. M. Nunes , J. Sarich , S. M. Wild

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media,…

Astrophysics of Galaxies · Physics 2024-07-17 Nannan Yue , Lile Wang , Thomas Bisbas , Donghui Quan , Di Li

AIM: We have recently developed a microscopic Monte Carlo approach to study surface chemistry on interstellar grains and the morphology of ice mantles. The method is designed to eliminate the problems inherent in the rate-equation formalism…

Astrophysics · Physics 2009-11-13 Q. Chang , H. M. Cuppen , E. Herbst

We present a detailed model for the thermal balance, chemistry, and radiative transfer within quiescent dense molecular cloud cores that contain a central protostar. Large variations in the gas temperature are expected to affect the…

Astrophysics · Physics 2009-10-30 S. D. Doty , D. A. Neufeld

Hot dense helium is studied with first-principles computer simulations. By combining path integral Monte Carlo and density functional molecular dynamics, a large temperature and density interval ranging from 1000 to 1000000 K and 0.4 to 5.4…

Materials Science · Physics 2015-05-13 Burkhard Militzer

The feasibility of contemporary gas-grain astrochemical models depends on the availability of accurate kinetics data, in particular, for surface processes. We study the sensitivity of gas-grain chemical models to the energy barrier Ea of…

Astrophysics of Galaxies · Physics 2020-05-20 Matjaž Simončič , Dmitry Semenov , Serge Krasnokutski , Thomas Henning , Cornelia Jäger

Using the APEX-12m telescope, continuum maps at 350~$\mu$m of eight gas-dust clouds from the southern hemisphere are obtained. Clouds are associated with the regions of massive star and star cluster formation and have dense cores. Core…

Astrophysics of Galaxies · Physics 2023-01-12 L. E. Pirogov

We present a new framework to study the time variation of fundamental constants in a model-independent way. Model independence implies more free parameters than assumed in previous studies. Using data from atomic clocks based on $^{87}$Sr,…

Understanding the dynamics and evolution of climate change and associated uncertainties is key for designing robust policy actions. Computer models are key tools in this scientific effort, which have now reached a high level of…

Methodology · Statistics 2024-04-30 Matteo Fontana , Massimo Tavoni , Simone Vantini

Sulphur-bearing species are often used to probe the evolution of hot cores since their abundances are particularly sensitive to physical and chemical variations. However, the chemistry of sulphur is not well understood in these regions,…

Solar and Stellar Astrophysics · Physics 2017-12-01 Thomas H. G. Vidal , Valentine Wakelam

The past decade has led to significant improvements in our understanding of the physical structure of the molecular cores of cold dark clouds. Observational efforts, in combination with improved knowledge of cloud structure, now provide…

Astrophysics · Physics 2007-05-23 Edwin A. Bergin

A solar-type system starts from an initial molecular core that acquires organic complexity as it evolves. The so-called prestellar cores that can be studied are rare, which has hampered our understanding of how organic chemistry sets in and…

Uncertainty quantification is a primary challenge for reliable modeling and simulation of complex stochastic dynamics. Such problems are typically plagued with incomplete information that may enter as uncertainty in the model parameters, or…

Probability · Mathematics 2015-07-15 Paul Dupuis , Markos A. Katsoulakis , Yannis Pantazis , Petr Plechac

There exist many methods for sensitivity analysis readily available to the practitioner. While each seeks to help the modeler answer the same general question -- How do sources of uncertainty or changes in the model inputs relate to…

Methodology · Statistics 2025-06-16 Devin Francom , Abigael Nachtsheim

Using mathematical models to assist in the interpretation of experiments is becoming increasingly important in research across applied mathematics, and in particular in biology and ecology. In this context, accurate parameter estimation is…

Statistics Theory · Mathematics 2025-04-29 Jie Qi , Ruth E. Baker

In the framework of the model inter-comparison study - Asia Phase II (MICS2), where eight models are compared over East Asia, this paper studies the influence of different parameterizations used in the aerosol module on the aerosol…

Atmospheric and Oceanic Physics · Physics 2007-05-23 Karine Sartelet , Hiroshi Hayami , Bruno Sportisse

We run numerical simulations of molecular clouds (MCs), adopting properties similar to those found in the Central Molecular Zone (CMZ) of the Milky Way. For this, we employ the moving mesh code Arepo and perform simulations which account…

Astrophysics of Galaxies · Physics 2016-09-21 Erik Bertram , Simon C. O. Glover , Paul C. Clark , Sarah E. Ragan , Ralf S. Klessen
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