The Experts below are selected from a list of 133602 Experts worldwide ranked by ideXlab platform

Hiroshi Niino - One of the best experts on this subject based on the ideXlab platform.

  • an improved mellor yamada level 3 model with condensation physics its design and verification
    Boundary-Layer Meteorology, 2004
    Co-Authors: Mikio Nakanishi, Hiroshi Niino
    Abstract:

    A Computational Scheme for an improved Mellor–Yamada(M–Y) Level-3 model with condensation physics is proposedand its performance is examined against large-eddy-simulationdata on radiation fog. The improved M–Y model greatlycorrects several shortcomings of the original M–Y model:the underestimations of the mixed-layer depth and themagnitude of turbulent kinetic energy, and the discrepanciesin the formation and dissipation times of the fog. Inaddition the improved M–Y model can reproduce theoccurrence of Kelvin–Helmholtz instability and periodicoscillations due to its energy cycle. It is shown that theoptimization of both the closure constants and the masterlength scale is required for this improvement. The improved M–Y model has an improvement also in theLevel-2.5 version. Although the performance of theLevel-2.5 version is not so good as that of the Level-3version, the former has the advantage of relatively lowComputational cost and is popularly used in operationalweather forecasts. Our Computational Scheme for theimproved M–Y model allows us to switch its hierarchylevels easily according to the purpose.

  • an improved mellor yamada level 3 model with condensation physics its design and verification
    Boundary-Layer Meteorology, 2004
    Co-Authors: Mikio Nakanishi, Hiroshi Niino
    Abstract:

    A Computational Scheme for an improved Mellor–Yamada(M–Y) Level-3 model with condensation physics is proposedand its performance is examined against large-eddy-simulationdata on radiation fog. The improved M–Y model greatlycorrects several shortcomings of the original M–Y model:the underestimations of the mixed-layer depth and themagnitude of turbulent kinetic energy, and the discrepanciesin the formation and dissipation times of the fog. Inaddition the improved M–Y model can reproduce theoccurrence of Kelvin–Helmholtz instability and periodicoscillations due to its energy cycle. It is shown that theoptimization of both the closure constants and the masterlength scale is required for this improvement.

Mikio Nakanishi - One of the best experts on this subject based on the ideXlab platform.

  • an improved mellor yamada level 3 model with condensation physics its design and verification
    Boundary-Layer Meteorology, 2004
    Co-Authors: Mikio Nakanishi, Hiroshi Niino
    Abstract:

    A Computational Scheme for an improved Mellor–Yamada(M–Y) Level-3 model with condensation physics is proposedand its performance is examined against large-eddy-simulationdata on radiation fog. The improved M–Y model greatlycorrects several shortcomings of the original M–Y model:the underestimations of the mixed-layer depth and themagnitude of turbulent kinetic energy, and the discrepanciesin the formation and dissipation times of the fog. Inaddition the improved M–Y model can reproduce theoccurrence of Kelvin–Helmholtz instability and periodicoscillations due to its energy cycle. It is shown that theoptimization of both the closure constants and the masterlength scale is required for this improvement. The improved M–Y model has an improvement also in theLevel-2.5 version. Although the performance of theLevel-2.5 version is not so good as that of the Level-3version, the former has the advantage of relatively lowComputational cost and is popularly used in operationalweather forecasts. Our Computational Scheme for theimproved M–Y model allows us to switch its hierarchylevels easily according to the purpose.

  • an improved mellor yamada level 3 model with condensation physics its design and verification
    Boundary-Layer Meteorology, 2004
    Co-Authors: Mikio Nakanishi, Hiroshi Niino
    Abstract:

    A Computational Scheme for an improved Mellor–Yamada(M–Y) Level-3 model with condensation physics is proposedand its performance is examined against large-eddy-simulationdata on radiation fog. The improved M–Y model greatlycorrects several shortcomings of the original M–Y model:the underestimations of the mixed-layer depth and themagnitude of turbulent kinetic energy, and the discrepanciesin the formation and dissipation times of the fog. Inaddition the improved M–Y model can reproduce theoccurrence of Kelvin–Helmholtz instability and periodicoscillations due to its energy cycle. It is shown that theoptimization of both the closure constants and the masterlength scale is required for this improvement.

Leonid B Krivdin - One of the best experts on this subject based on the ideXlab platform.

  • dft Computational Schemes for 1h and 13c nmr chemical shifts of natural products exemplified by strychnine
    Magnetic Resonance in Chemistry, 2020
    Co-Authors: Valentin A Semenov, Leonid B Krivdin
    Abstract:

    A number of Computational Schemes based on different Density Functional Theory (DFT) functionals in combination with a number of basis sets were tested in the calculation of 1 H and 13 C NMR chemical shifts of strychnine, as a typical representative of the vitally important natural products, and used as a challenging benchmark and a rigorous test for such calculations. It was found that the most accurate Computational Scheme, as compared with experiment, was PBE0/pcSseg-4//pcseg-3 characterized by a mean absolute error of 0.07 ppm for the range of about 7 ppm for 1 H NMR chemical shifts and that of only 1.13 ppm for 13 C NMR chemical shifts spread over the range of about 150 ppm. For more practical purposes, including investigation of larger molecules from this series, a much more economical Computational Scheme, PBE0/pcSseg-2//pcseg-2, characterized by almost the same accuracy and much less Computational demand, was recommended.

  • four component relativistic dft calculations of 77 se nmr chemical shifts a gateway to a reliable Computational Scheme for the medium sized organoselenium molecules
    Journal of Computational Chemistry, 2015
    Co-Authors: Yury Yu Rusakov, Leonid B Krivdin
    Abstract:

    A versatile high-accuracy Computational Scheme for the (77) Se nuclear magnetic resonance (NMR) chemical shifts of the medium-sized organoselenium compounds is suggested within a framework of a full four-component relativistic density functional theory (DFT). The main accuracy factors (DFT functionals, relativistic geometry, vibrational corrections, and solvent effects) are addressed. The best result is achieved with NMR-oriented KT2 functional of Keal-Tozer characterized by a fairly small error of only 30 ppm for the span of about 1700 ppm (<2%).

Guoqiang Wang - One of the best experts on this subject based on the ideXlab platform.

R Mittra - One of the best experts on this subject based on the ideXlab platform.

  • scattering analysis of plasmonic nanorod antennas a novel numerically efficient Computational Scheme utilizing macro basis functions
    Journal of Applied Physics, 2011
    Co-Authors: Arash Rashidi, Hossein Mosallaei, R Mittra
    Abstract:

    In this paper we introduce a versatile and numerically efficient Computational technique to model the problem of scattering from plasmonic nanorod antennas. The key to achieving the numerical efficiency is to utilize macro basis functions (MBFs) that taking into account the physics of the problem to reduce the size of matrix equation we need to solve. Closed form formulations are presented for computing the fields by the transverse and longitudinal MBFs that enable us to generate the required matrix elements rapidly, while ensuring that the matrix is well-conditioned. We show that the transverse and longitudinal components of polarization current and all of the components of the scattered fields can be computed very accurately by employing only a few MBFs, i.e., by solving a relatively small-size matrix equation. The accuracy of our modeling technique has been successfully demonstrated by comparing the simulation results with those derived by using the finite difference time domain (FDTD) technique, which...