SCI Publications
2001
R.M. Kirby, G.E. Karniadakis, O. Mikulchenko, K. Mayaram.
“An Integrated Simulator for Coupled Domain Problems in MEMS,” In Journal of Microelectromechanical Systems, Vol. 10, No. 3, pp. 379--399. 2001.
J.M. Kniss, G. Kindlmann, C.D. Hansen.
“Interactive Volume Rendering Using Multi-Dimensional Transfer Functions and Direct Manipulation Widgets,” In Proceeding of IEEE Visualization 2001, pp. 255--262. October, 2001.
J.M. Kniss, P. McCormick, A. McPherson, J. Ahrens, J. Painter, A. Keahey, C.D. Hansen.
“Interactive Texture-based Volume Rendering for Large Datasets,” In IEEE Comp. Graph. & Applic., Vol. 21, No. 4, pp. 52--61. July/August, 2001.
J.M. Kniss, P. McCormick, A. McPherson, J. Ahrens, J. Painter, A. Keahey, C.D. Hansen.
“T-Rex, Texture-based Volume Rendering for Extremely Large Datasets,” In IEEE Comp. Graph. & Applic., Vol. 21, No. 4, pp. 52--61. 2001.
D.H. Laidlaw, R.M. Kirby, J.S. Davidson, T.S. Miller, M. da Silva, W.H. Warren, M. Tarr.
“Quantitative Comparative Evaluation of 2D Vector Field Visualization Methods,” In Proceedings of IEEE Visualization 2001, San Diego, CA, pp. 143--150. October, 2001.
I. Lagzi, A.S. Tomlin, T.Turanyi, L.Haszpra, M.Berzins.
“The Simulation of Photochemical Smog Episodes in Hungary and Central Europe Using Adaptive Gridding Models,” In Lecture Notes in Computer Science (LCNS), Computational Science - ICCS 2001, Vol. 2074/2001, Springer Berlin / Heidelberg, pp. 67--76. 2001.
ISBN: 978-3-540-42233-4
J.P. Lewis, K.R. Glaesemann, G.A. Voth, J. Fritsch, A.A. Demkov, J. Ortega, O.F. Sankey.
“Further Developments in the Local-orbital Density-functional Theory Tight-Binding Method,” In Physical Review, B, Vol. 64, No. 19, pp. 195103--195113. 2001.
DOI: 10.1103/PhysRevB.64.195103
Improvements to the Sankey-Niklewaki method [O. F. Sankey and D. J. Niklewski, Phys. Rev. B 40, 3979 (1989)] for computing total energies and forces, within an ab initio tight-binding formalism, are presented here. In particular, the improved method (called FIREBALL) uses the separable pseudopotential (Hamann or Troullier) and goes beyond the minimal sp2 basis set of the Sankey-Niklewski method, allowing for double numerical basis sets with the addition of polarization orbitals and d orbitals to the basis set. A major improvement includes the use of more complex exchange-correlation functionals, such as Becke exchange with the Lee-Yang-Parr correlation. Results for Cu and GaN band structures using d orbitals within the improved method are reported; the results for GaN are greatly improved compared to the minimal basis results. Finally, to demonstrate the flexibility of the method, results for the H2O dimer system and the energetics of a gas-phase octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine molecule are reported.
P. Lindstrom, V. Pascucci.
“Visualization of Large Terrains Made Easy,” In Proceedings of the 12th Annual IEEE Conference on Visualization (VIS-01), San Diego, CA, Note: UCRL-JC-144753, IEEE Computer Society, pp. 363--370, 574. October 21-26, 2001.
Y. Livnat, C.D. Hansen, S.G. Parker, C.R. Johnson.
“Isosurface extraction for large-scale datasets,” In Proceedings of Scientific Visualization -Dagstuhl`2000, Edited by F. Post, 2001.
P. Lorenzen, S. Joshi, G. Gerig, E. Bullitt.
“Tumor-Induced Structural Radiometric Asymmetry in Brain Images,” In Workshop on Mathematical Methods in Biomedical Image Analysis (MMBIA), pp. 163--170. 2001, 2001.
K. Ma, S.G. Parker.
“Massively Parallel Software Rendering for Visualizing Large-Scale DataSets,” In IEEE Trans. Vis & Comp. Graph., pp. 72--83. July/August, 2001.
R.S. MacLeod, B. Yilmaz, B. Taccardi, B.B. Punske, Y. Serina, D.H. Brooks.
“Direct and Inverse Methods for Cardiac Mapping Using Multielectrode Catheter Measurements,” In Journal of Biomedizinische Technik, Vol. 46(supp), pp. 207--209. 2001.
R.S. MacLeod, B.B. Punske, B. Yilmaz, S. Shome, B. Taccardi.
“The Role of Heart Rate in Myocardial Ischemia From Restricted Coronary Perfusion,” In J. Electrocardiol., Vol. 34 (supp), Note: ISCE conference paper, pp. 43--51. 2001.
J. McCorquodale, J.D. de St. Germain, S.G. Parker, C.R. Johnson.
“The Uintah Parallelism Infrastructure: A Performance Evaluation on the SGI Origin 2000,” In Proceedings of The 5th International Conference on High-Performance Computing, Seattle, Mar, 2001.
S. Mendez, J.G. Curro, M. Putz, D. Bedrov, G.D. Smith.
“An Integral Equation Theory for Polymer Solutions: Explicit Inclusion of the Solvent Molecules,” In Journal of Chemical Physics, Vol. 115, No. 12, pp. 5669--5678. 2001.
DOI: 10.1063/1.1397333
Self-consistent Polymer Reference Interaction Site Model (PRISM) calculations and molecular dynamics (MD) simulations were performed on athermal solutions of linear polymers. Unlike most previous treatments of polymer solutions, we explicitly included the solvent molecules. The polymers were modeled as tangent site chains and the solvent molecules were taken to be spherical sites having the same intermolecular potential as the polymer sites. The PRISM theory was solved self-consistently for both the single chain structure and intermolecular correlations as a function of chain length and concentration. The rms end-to-end distance from PRISM theory was found to be in agreement with corresponding MD simulations, and exhibited molecular weight dependence in accordance with scaling predictions in the dilute and concentrated solution limits. The presence of explicit solvent molecules had a significant effect on the packing of the polymer by inducing additional structure in the intermolecular radial distribution function between polymer sites. Using the direct correlation functions from the athermal solution and the random phase approximation, we were able to estimate the spinodal curves for solutions when polymer and solvent attractions were turned on. We found significant deviations from Flory-Huggins theory that are likely due to compressibility and nonrandom mixing effects.
M. Miller, C. Moulding, J. Dongarra, C.R. Johnson.
“Grid-enabling Problem Solving Environments: A Case Study of SCIRun and Netsolv,” In Proceedings of The 5th International Conference on High-Performance Computing, 2001 Advanced Simulation Technologies Conference, Society for Modeling and Simulation International, pp. 98--103. April, 2001.
V. Pascucci, R.J. Frank.
“Global Static Indexing for Real-time Exploration of Very Large Regular Grids,” In Proceedings of Supercomputing 2001, Note: UCRL-JC-144754, ACM, Nov, 2001.
V. Pascucci.
“On the Topology of the Level Sets of a Scalar Field,” In Proceedings of the 13th Canadian Conference on Computational Geometry, Note: UCRL-JC-142262, pp. 141--144. August, 2001.
M. Pernice, M.D. Tocci.
“A Multigrid-Preconditioned Newton-Krylov Method for the Incompressible Navier-Stokes Equations,” In SIAM Journal on Scientific Computing, Vol. 23, No. 2, pp. 398--418. 2001.
DOI: 10.1137/S1064827500372250
Globalized inexact Newton methods are well suited for solving large-scale systems of nonlinear equations. When combined with a Krylov iterative method, an explicit Jacobian is never needed, and the resulting matrix-free Newton--Krylov method greatly simplifies application of the method to complex problems. Despite asymptotically superlinear rates of convergence, the overall efficiency of a Newton--Krylov solver is determined by the preconditioner. High-quality preconditioners can be constructed from methods that incorporate problem-specific information, and for the incompressible Navier--Stokes equations, classical pressure-correction methods such as SIMPLE and SIMPLER fulfill this requirement. A preconditioner is constructed by using these pressure-correction methods as smoothers in a linear multigrid procedure. The effectiveness of the resulting Newton--Krylov-multigrid method is demonstrated on benchmark incompressible flow problems.
J.D. Peterson, S. Vyazovkin, C.A. Wight.
“Kinetics of the Thermal and Thermooxidative Degradation of Polystyrene, Polyethylene and Poly(propylene),” In Macromolecular Chemistry and Physics, Vol. 202, No. 6, pp. 775--784. March, 2001.
DOI: 10.1002/1521-3935(20010301)202:63.0.CO;2-G
The thermal degradations of polystyrene (PS), polyethylene (PE), and poly(propylene) (PP) have been studied in both inert nitrogen and air atmospheres by using thermogravimetry and differential scanning calorimetry. The model-free isoconversional method has been employed to calculate activation energies as a function of the extent of degradation. The obtained dependencies are interpreted in terms of degradation mechanisms. Under nitrogen, the thermal degradation of polymers follows a random scission pathway that has an activation energy ≈200 kJ·mol–1 for PS and 240 and 250 kJ·mol–1 for PE and PP, respectively. Lower values (≈150 kJ·mol–1) are observed for the initial stages of the thermal degradation of PE and PS; this suggests that degradation is initiated at weak links. In air, the thermoxidative degradation occurs via a pathway that involves decomposition of polymer peroxide and exhibits an activation energy of 125 kJ·mol–1 for PS and 80 and 90 kJ·mol–1, for PE and PP respectively.