Svetlana Kyas

Last Name

Kyas

First Name

Svetlana

ORCID

0000-0001-7159-9055

Show all metadata

Search Results

Publications 1 - 10 of 21

Space‐Time Isogeometric Analysis of Parabolic Diffusion Problems in Moving Spatial Domains
Kyas, Svetlana; Langer, Ulrich; Repin, Sergey (2019)
Proceedings in Applied Mathematics and Mechanics
Towards a Model-Based Interpretation of Measurements of Mineralogical and Chemical Compositions
Hauser, Juerg; Miron, George D.; Kyas, Svetlana; et al. (2024)
Mathematical Geosciences
We introduce a new methodology for inference of fluid composition from measurements of mineralogical or chemical compositions, expanding upon the use of reactive transport models to understand hydrothermal alteration processes. The reactive transport models are used to impute a latent variable explanatory mechanism in the formation of hydrothermal alteration zones and mineral deposits. An expectation maximisation algorithm is then employed to solve the joint problem of identifying alteration zones in the measured data and estimating the fluid composition, based on the fit between the mineral abundances in the measured and predicted alteration zones. Using the hydrothermal alteration of granite as a test case (greisenisation), a range of synthetic tests is presented to illustrate how the methodology enables objective inference of the mineralising fluid. For field data from the East Kemptville tin deposit in Nova Scotia, the technique generates inferences for the fluid composition which compare favourably with previous independent estimates, demonstrating the feasibility of the proposed calibration methodology.
Adaptive Space-Time Isogeometric Analysis of Parabolic Evolution Problems
Kyas, Svetlana (2018)
Guaranteed error control bounds for the stabilised space-time IgA approximations to parabolic problems
Langer, Ulrich; Kyas, Svetlana; Repin, Sergey (2017)
RICAM-Report
Accelerating geochemical equilibrium and kinetics calculation for modeling reactive transport in porous media
Kyas, Svetlana; Saar, Martin O.; Leal, Allan (2019)
Adaptive space-time isogeometric analysis for parabolic evolution problems
Langer, Ulrich; Kyas, Svetlana; Repin, Sergey (2019)
Radon Series on Computational and Applied Mathematics ~ Applications to Partial Differential Equations
Adaptive space-time isogeometric analysis for parabolic evolution problems
Langer, Ulrich; Kyas, Svetlana; Repin, Sergey (2018)
RICAM-Report
Correction to: Accelerating Reactive Transport Modeling: On-Demand Machine Learning Algorithm for Chemical Equilibrium Calculations
Leal, Allan M.M.; Kyas, Svetlana; Kulik, Dmitrii A.; et al. (2020)
Transport in Porous Media
Ultra-fast geochemical calculations in reactive transport modeling with on-demand learning algorithms
Moreira Mulin Leal, Allan; Kyas, Svetlana; Kulik, Dmitrii A.; et al. (2020)
Computational Methods in Water Resources XXIII (CMWR 2020). Proceedings
Reactive transport simulations are in general time-consuming due to costly geochemical equilibrium and/or kinetics calculations. These may account for over 99% of all computing costs when complex chemical systems are considered, because those computations are needed one or more times in each cell of high-resolution meshes, at every time step of the simulation. To reduce their computing cost by orders of magnitude, we present an on-demand learning strategy that enables geochemical calculations to be rapidly and accurately predicted using previously learned geochemical states. We use sensitivity derivatives combined with first-order Taylor estimations to achieve these fast computations. These derivatives enable a complete bypass of expensive operations such as evaluation of thermodynamic properties (e.g., species activities, fugacities, equations of state), solution of matrix equations in each Newton iteration, time integration of ordinary differential equations, and more. We present reactive transport simulations, considering realistic chemical systems and strong non-ideal thermodynamic behavior, in which geochemical calculations were speed up by a factor of 100 to 200 using this on-demand learning algorithm.
Accelerating reactive transport simulations with on-demand machine learning
Leal, Allan M.M.; Kyas, Svetlana; Kulik, Dimitrii A.; et al. (2020)
Abstract Volume 18th Swiss Geoscience Meeting

Publications 1 - 10 of 21

Svetlana Kyas

Last Name

First Name

ORCID

Organisational unit

Filters

Search Results