# Systematic parameter inference in stochastic mesoscopic modeling

## Abstract

We propose a method to efficiently determine the optimal coarse-grained force field in mesoscopic stochastic simulations of Newtonian fluid and polymer melt systems modeled by dissipative particle dynamics (DPD) and energy conserving dissipative particle dynamics (eDPD). The response surfaces of various target properties (viscosity, diffusivity, pressure, etc.) with respect to model parameters are constructed based on the generalized polynomial chaos (gPC) expansion using simulation results on sampling points (e.g., individual parameter sets). To alleviate the computational cost to evaluate the target properties, we employ the compressive sensing method to compute the coefficients of the dominant gPC terms given the prior knowledge that the coefficients are “sparse”. The proposed method shows comparable accuracy with the standard probabilistic collocation method (PCM) while it imposes a much weaker restriction on the number of the simulation samples especially for systems with high dimensional parametric space. Fully access to the response surfaces within the confidence range enables us to infer the optimal force parameters given the desirable values of target properties at the macroscopic scale. Moreover, it enables us to investigate the intrinsic relationship between the model parameters, identify possible degeneracies in the parameter space, and optimize the model by eliminating model redundancies. The proposedmore »

- Authors:

- Pacific Northwest National Laboratory, Richland, WA 99352 (United States)
- Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)

- Publication Date:

- OSTI Identifier:
- 22622248

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Computational Physics; Journal Volume: 330; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCURACY; CHAOS THEORY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; EXPANSION; FLUIDS; POLYMERS; POLYNOMIALS; PROBABILISTIC ESTIMATION; REDUCTION; REDUNDANCY; STOCHASTIC PROCESSES; SURFACES; VISCOSITY

### Citation Formats

```
Lei, Huan, Yang, Xiu, Li, Zhen, and Karniadakis, George Em, E-mail: george_karniadakis@brown.edu.
```*Systematic parameter inference in stochastic mesoscopic modeling*. United States: N. p., 2017.
Web. doi:10.1016/J.JCP.2016.10.029.

```
Lei, Huan, Yang, Xiu, Li, Zhen, & Karniadakis, George Em, E-mail: george_karniadakis@brown.edu.
```*Systematic parameter inference in stochastic mesoscopic modeling*. United States. doi:10.1016/J.JCP.2016.10.029.

```
Lei, Huan, Yang, Xiu, Li, Zhen, and Karniadakis, George Em, E-mail: george_karniadakis@brown.edu. Wed .
"Systematic parameter inference in stochastic mesoscopic modeling". United States.
doi:10.1016/J.JCP.2016.10.029.
```

```
@article{osti_22622248,
```

title = {Systematic parameter inference in stochastic mesoscopic modeling},

author = {Lei, Huan and Yang, Xiu and Li, Zhen and Karniadakis, George Em, E-mail: george_karniadakis@brown.edu},

abstractNote = {We propose a method to efficiently determine the optimal coarse-grained force field in mesoscopic stochastic simulations of Newtonian fluid and polymer melt systems modeled by dissipative particle dynamics (DPD) and energy conserving dissipative particle dynamics (eDPD). The response surfaces of various target properties (viscosity, diffusivity, pressure, etc.) with respect to model parameters are constructed based on the generalized polynomial chaos (gPC) expansion using simulation results on sampling points (e.g., individual parameter sets). To alleviate the computational cost to evaluate the target properties, we employ the compressive sensing method to compute the coefficients of the dominant gPC terms given the prior knowledge that the coefficients are “sparse”. The proposed method shows comparable accuracy with the standard probabilistic collocation method (PCM) while it imposes a much weaker restriction on the number of the simulation samples especially for systems with high dimensional parametric space. Fully access to the response surfaces within the confidence range enables us to infer the optimal force parameters given the desirable values of target properties at the macroscopic scale. Moreover, it enables us to investigate the intrinsic relationship between the model parameters, identify possible degeneracies in the parameter space, and optimize the model by eliminating model redundancies. The proposed method provides an efficient alternative approach for constructing mesoscopic models by inferring model parameters to recover target properties of the physics systems (e.g., from experimental measurements), where those force field parameters and formulation cannot be derived from the microscopic level in a straight forward way.},

doi = {10.1016/J.JCP.2016.10.029},

journal = {Journal of Computational Physics},

number = ,

volume = 330,

place = {United States},

year = {Wed Feb 01 00:00:00 EST 2017},

month = {Wed Feb 01 00:00:00 EST 2017}

}