Biomedical subjects

Y H Qian

Publications and source records attributed to Y H Qian.

3 recordsLinked to original sources

PubMed2001

Effective volumetric lattice Boltzmann scheme.

An efficient fractional volumetric scheme is proposed for lattice Boltzmann method (LBM). By reducing the effective time step, the scheme possesses much better stability particularly for thermal LBM. The same accuracy and simplicity of the standard LBM are preserved for achieving the Navier-Stokes equation. Since the effective viscosity is reduced by the fraction factor p, the scheme becomes very effective for simulating high Reynolds number thermal flows.

Journal Article↗

PubMed2000

"Coarse" stability and bifurcation analysis using time-steppers: a reaction-diffusion example.

Evolutionary, pattern forming partial differential equations (PDEs) are often derived as limiting descriptions of microscopic, kinetic theory-based models of molecular processes (e.g., reaction and diffusion). The PDE dynamic behavior can be probed through direct simulation (time integration) or, more systematically, through stability/bifurcation calculations; time-stepper-based approaches, like the Recursive Projection Method [Shroff, G. M. & Keller, H. B. (1993) SIAM J. Numer. Anal. 30, 1099-1120] provide an attractive framework for the latter. We demonstrate an adaptation of this approach that allows for a direct, effective ("coarse") bifurcation analysis of microscopic, kinetic-based models; this is illustrated through a comparative study of the FitzHugh-Nagumo PDE and of a corresponding Lattice-Boltzmann model.

Computer Simulation↗

PubMed1993

[Long-term results of surgical treatment of patent ductus arteriosus in adults].

284 patients with patent ductus arteriosus were operated. Among them, 81 aged from 20-41. Special managements were made because of their serious pathologic changes. There was no operative mortality. 72 patients (88.9%) were followed up for 1-17 years. The results of follow-up indicated that the postoperative cardiopulmonary function improved greatly. 63 patients returned normal work. The long-term results were satisfactory.

Adult↗