GILA User's Manual

Christon, Mark A.

doi:10.2172/820886

Cited by 3 publications

(3 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Moldy package [21] was used for the simulations, performed in the N PT ensemble (constant number of particles together with constant pressure and temperature). Periodic boundary conditions were applied, meaning that if a particle leaves the simulation box, an identical particle enters on the other side.…”

Section: Technical Detailsmentioning

confidence: 99%

Study of the high-pressure helium phase diagram using molecular dynamics

Koči

Ahuja

Belonoshko

et al. 2006

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The rich occurrence of helium and hydrogen in space makes their properties highly interesting. By means of molecular dynamics (MD), we have examined two interatomic potentials for 4 He. Both potentials are demonstrated to reproduce high-pressure solid and liquid equation of state (EOS) data. The EOS, solid-solid transitions and melting at high pressures (P) were studied using a two-phase method. The Buckingham potential shows a good agreement with theoretical and experimental EOS, but does not reproduce experimental melting data. The Aziz potential shows a perfect match with theoretical melting data. We conclude that there is a stable body-centred-cubic (bcc) phase for 4 He at temperatures (T ) above 340 K and pressures above 22 GPa for the Buckingham potential, whereas no bcc phase is found for the Aziz potential in the applied PT range.

show abstract

Section: Technical Detailsmentioning

confidence: 99%

Study of the high-pressure helium phase diagram using molecular dynamics

Koči

Ahuja

Belonoshko

et al. 2006

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…In [29]- [31], an activity-based model and a traffic assignment model are jointly calibrated. Papers [29], [30] calibrate both the MATSim software and CEMDAP [32], with MATSim receiving the final calibration based on traffic counts. In [29], for example, CEMDAP after the calibration produces a set of 5 eligible daily activity schedules but then it is up to MATSim (and the related module CaDyTS) to score them according to how well they reproduce the supply side measurements so that the supply performance does not result in a change of behavioral parameters.…”

Section: A Calibration Approaches In Transport Modelingmentioning

confidence: 99%

A Bayesian Optimization Approach for Calibrating Large-Scale Activity-Based Transport Models

Agriesti,

Kuzmanovski,

Hollmén

et al. 2023

IEEE Open J. Intell. Transp. Syst.

View full text Add to dashboard Cite

Addressing complexity in transportation in cases such as disruptive trends or disaggregated management strategies has become increasingly important. This in turn is resulting in the rising adoption of Agent-Based and Activity-Based modeling. Still, a broad adoption is hindered by the high complexity and computational needs. For example, hundreds of parameters are involved in the calibration of Activity-Based models focused on behavioral theory, to properly frame the required detailed socio-economical characteristics. To address this challenge, this paper presents a novel Bayesian Optimization approach that incorporates a surrogate model defined as an improved Random Forest to automate the calibration process of the behavioral parameters. The presented solution calibrates the largest set of parameters yet, according to the literature, by combining state-of-the-art methods. To the best of the authors' knowledge, this is the first work in which such a high dimensionality is tackled in sequential model-based algorithm configuration theory. The proposed method is tested in the city of Tallinn, Estonia, for which the calibration of 477 behavioral parameters is carried out. The calibration process results in a satisfactory performance for all the major indicators, the OD matrix average mismatch is equal to 15.92 vehicles per day while the error for the overall number of trips is equal to 4%.

show abstract

“…Also, since the older codes are not in development, the codebases are more stable. Codes investigated for possible use in the demonstration problem include MP-Salsa, Vulcan, the "FAA" code, [7,8] a new version of the Coyote/Nachos code, [9] and GILA [10]; these are all 3D CFD codes. MP-Salsa is an equilibrium/transient finite element code; Vulcan is a transient block-structured code; the FAA code, developed to analyze smoke transport in airplanes, uses a body-fitted mesh; and GILA is a transient finite element code.…”

Section: Selected Demonstration Problemmentioning

confidence: 99%

Advanced nuclear energy analysis technology.

Gauntt¹,

Murata²,

Romero³

et al. 2004

View full text Add to dashboard Cite

A two-year effort focused on applying ASCI technology developed for the analysis of weapons systems to the state-of-the-art accident analysis of a nuclear reactor system was proposed. The Sandia SIERRA parallel computing platform for ASCI codes includes high-fidelity thermal, fluids, and structural codes whose coupling through SIERRA can be specifically tailored to the particular problem at hand to analyze complex multiphysics problems. Presently, however, the suite lacks several physics modules unique to the analysis of nuclear reactors. The NRC MELCOR code, not presently part of SIERRA, was developed to analyze severe accidents in present-technology reactor systems. We attempted to: 1) evaluate the SIERRA code suite for its current applicability to the analysis of next generation nuclear reactors, and the feasibility of implementing MELCOR models into the SIERRA suite, 2) examine the possibility of augmenting ASCI codes or alternatives by coupling to the MELCOR code, or -4-portions thereof, to address physics particular to nuclear reactor issues, especially those facing next generation reactor designs, and 3) apply the coupled code set to a demonstration problem involving a nuclear reactor system. We were successful in completing the first two in sufficient detail to determine that an extensive demonstration problem was not feasible at this time. In the future, completion of this research would demonstrate the feasibility of performing high fidelity and rapid analyses of safety and design issues needed to support the development of next generation power reactor systems.-5-

show abstract

GILA User's Manual

Cited by 3 publications

References 42 publications

Study of the high-pressure helium phase diagram using molecular dynamics

Study of the high-pressure helium phase diagram using molecular dynamics

A Bayesian Optimization Approach for Calibrating Large-Scale Activity-Based Transport Models

Advanced nuclear energy analysis technology.

Contact Info

Product

Resources

About