The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform

Seong Woo Kim - One of the best experts on this subject based on the ideXlab platform.

  • objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C3F8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C3F8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas-fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas-fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas-fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p < 0.001). The estimated gas area was 52.56 and 60.82 mm2 at 10 days (p = 0.025) and 19.83 and 33.86 mm2 at four weeks (p < 0.001). The gas tamponade areas were objectively shown to be greater under the 20% concentration than the 14% concentration of C3F8 at 10 days and 4 weeks postoperatively using UWF Stereographic Projection images.

  • Objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra-widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C_3F_8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C_3F_8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas–fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas–fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas–fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p 

E. Curotto - One of the best experts on this subject based on the ideXlab platform.

  • A Stereographic Projection path integral study of the coupling between the orientation and the bending degrees of freedom of water
    The Journal of chemical physics, 2008
    Co-Authors: E. Curotto, David L. Freeman, J. D. Doll
    Abstract:

    A Monte Carlo path integral method to study the coupling between the rotation and bending degrees of freedom for water is developed. It is demonstrated that soft internal degrees of freedom that are not stretching in nature can be mapped with Stereographic Projection coordinates. For water, the bending coordinate is orthogonal to the Stereographic Projection coordinates used to map its orientation. Methods are developed to compute the classical and quantum Jacobian terms so that the proper infinitely stiff spring constant limit is recovered in the classical limit, and so that the nonconstant nature of the Riemann Cartan curvature scalar is properly accounted in the quantum simulations. The theory is used to investigate the effects of the geometric coupling between the bending and the rotating degrees of freedom for the water monomer in an external field in the 250 to 500 K range. We detect no evidence of geometric coupling between the bending degree of freedom and the orientations.

  • Stereographic Projection path integral simulations of hcl n clusters n 2 5 evidence of quantum induced melting in small hydrogen bonded networks
    Journal of Chemical Physics, 2008
    Co-Authors: Michael W. Avilés, Michelle L Mccandless, E. Curotto
    Abstract:

    We investigate the quantum thermodynamic properties of small (HCl)(n) clusters using Stereographic Projection path integral simulations. The HCl stretches are rigid, the orientations are mapped with Stereographic Projection coordinates, and we make use of the reweighted random series techniques to obtain cubic convergence with respect to the number of path coefficients. Path integral simulations are converged at and above 10 K for the pentamer and above 15 K for the dimer and the trimer. None of the systems display a melting feature in the classical limit. We find an evidence of quantum induced melting between 15 and 45 K.

  • Stereographic Projection diffusion monte carlo spdmc algorithms for molecular condensed matter
    Journal of Physical Chemistry A, 2007
    Co-Authors: Michael W. Avilés, E. Curotto
    Abstract:

    We develop and test three algorithms for diffusion Monte Carlo simulations in non-Euclidean manifolds. The methods are based on the construction of the "velocity" distribution by rejection techniques and are capable of functioning in a broad class of non-Euclidean spaces generated by holonomic constraints. The formulation of the propagator for non-Euclidean manifolds avoids the use of Lagrange multipliers; it is derived instead from the Feynman quantization in manifolds proposed by DeWitt. The manifolds are mapped onto R d by using Stereographic Projection coordinates. Numerical tests are conducted for the particle in a ring of unit radius subjected to a sinusoidal potential, for the electron in the field of an infinitely massive proton, and for a water molecule modeled as an asymmetric top subjected to an external field.

  • Stereographic Projection path-integral simulations of (HF)n clusters
    The Journal of chemical physics, 2006
    Co-Authors: Michael W. Avilés, Philip T. Gray, E. Curotto
    Abstract:

    We perform several quantum canonical ensemble simulations of (HF)(n) clusters. The HF stretches are rigid, and the Stereographic Projection path-integral method is employed for the simulation in the resulting curved configuration space. We make use of the reweighted random series techniques to accelerate the convergence of the path-integral simulation with respect to the number of path coefficients. We develop and test estimators for the total energy and heat capacity based on a finite difference approach for non-Euclidean spaces. The quantum effects at temperatures below 400 K are substantial for all sizes. We observe interesting thermodynamic behaviors in the quantum simulations of the octamer and the heptamer.

  • partial averaging and the centroid virial estimator for Stereographic Projection path integral simulations in curved spaces
    Journal of Chemical Physics, 2005
    Co-Authors: Michael W. Avilés, E. Curotto
    Abstract:

    We develop and test three different partial averaging theories for the Stereographic Projection path integral in curved spaces. Additionally, we adapt and test the centroid virial estimator for the kinetic energy in curved spaces. We tested both a confining as well as a nonconfining potential for the particle in a ring. All three partial averaging theories are demonstrated to converge linearly in the asymptotic region with kmax−2, the number of Fourier coefficients. We use an error estimator to determine the optimal parameters for an extrapolation to infinite kmax. We verify that the centroid virial estimator (derived from the primitive DeWitt path-integral formula) converges to the kinetic energy for both confining and nonconfining potentials.

Mihyun Choi - One of the best experts on this subject based on the ideXlab platform.

  • objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C3F8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C3F8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas-fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas-fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas-fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p < 0.001). The estimated gas area was 52.56 and 60.82 mm2 at 10 days (p = 0.025) and 19.83 and 33.86 mm2 at four weeks (p < 0.001). The gas tamponade areas were objectively shown to be greater under the 20% concentration than the 14% concentration of C3F8 at 10 days and 4 weeks postoperatively using UWF Stereographic Projection images.

  • Objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra-widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C_3F_8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C_3F_8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas–fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas–fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas–fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p 

Suji Hong - One of the best experts on this subject based on the ideXlab platform.

  • objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C3F8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C3F8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas-fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas-fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas-fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p < 0.001). The estimated gas area was 52.56 and 60.82 mm2 at 10 days (p = 0.025) and 19.83 and 33.86 mm2 at four weeks (p < 0.001). The gas tamponade areas were objectively shown to be greater under the 20% concentration than the 14% concentration of C3F8 at 10 days and 4 weeks postoperatively using UWF Stereographic Projection images.

  • Objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra-widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C_3F_8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C_3F_8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas–fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas–fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas–fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p 

Cheolmin Yun - One of the best experts on this subject based on the ideXlab platform.

  • objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C3F8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C3F8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas-fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas-fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas-fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p < 0.001). The estimated gas area was 52.56 and 60.82 mm2 at 10 days (p = 0.025) and 19.83 and 33.86 mm2 at four weeks (p < 0.001). The gas tamponade areas were objectively shown to be greater under the 20% concentration than the 14% concentration of C3F8 at 10 days and 4 weeks postoperatively using UWF Stereographic Projection images.

  • Objective analysis of perfluoropropane tamponade area after pars plana vitrectomy using ultra-widefield fundus Stereographic Projection images
    Scientific Reports, 2020
    Co-Authors: Mihyun Choi, Suji Hong, Cheolmin Yun, Seong Woo Kim
    Abstract:

    To objectively analyze the gas tamponade area in patients with different concentrations of perfluoropropane (C_3F_8) after pars plana vitrectomy (PPV), retrospective analysis was performed in patients diagnosed with retinal detachment or macular hole and underwent PPV with C_3F_8 tamponade of two concentrations (14% and 20%). The ultra-widefield fundus (UWF) images at one and 10 days and four weeks postoperatively were corrected using Stereographic Projection to adjust peripheral distortion. The gas–fluid interface curvatures were delineated using UWF Stereographic Projection images, and the gas–fluid area ratio and estimated gas area were calculated at each concentration. Among 65 eyes, 30 were in the 14% group and 35 were in the 20% group. The gas–fluid area ratio was 0.71 in the 14% group and 0.83 in the 20% group at 10 days (p = 0.046) and 0.27 and 0.45, respectively, at four weeks postoperatively (p