Jysoo Lee

Angle of repose and angle of marginal stability : molecular dynamics of granular particles

The authors present an implementation of realistic static friction in molecular dynamics (MD) simulations of granular particles. In their model, to break contact between two particles, one has to apply a finite amount of force, determined by the Coulomb criterion. Using a two-dimensional model, they show that piles generated by avalanches have a finite angle of repose theta R (finite slopes). Furthermore, these piles are stable under tilting by an angle smaller than a non-zero tilting angle theta T, showing that theta R is different from the angle of marginal stability theta MS, which is the maximum angle of stable piles. These measured angles are compared to a theoretical approximation. They also measure theta MS by continuously adding particles on the top of a stable pile.

Superlattice, rhombus, square, and hexagonal standing waves in magnetically driven ferrofluid surface

Standing wave patterns that arise on the surface of ferrofluids by (single frequency) parametric forcing with an ac magnetic field are investigated experimentally. Depending on the frequency and amplitude of the forcing, the system exhibits various patterns including a superlattice and subharmonic rhombuses as well as conventional harmonic hexagons and subharmonic squares. The superlattice arises in a bicritical situation where harmonic and subharmonic modes collide. The rhombic pattern arises due to the nonmonotonic dispersion relation of a ferrofluid.

Nonlinear correction to Darcy's law for a flow through periodic arrays of elliptic cylinders

Nonlinear correction to Darcys law for a two-dimensional flow through periodic arrays of elliptic cylinders is investigated using the lattice Boltzmann equation method. For small Reynolds number, we find that the leading correction for the anisotropic system is a third-degree homogeneous function of the average fluid velocity, and possible terms of the function are determined by symmetry. The dimensionless coefficients of the terms, which depend only on the geometry of the system, are determined for various values of the volume fraction and eccentricity of the cylinders. Also, it is found that small deformation of the shape of the cylinder does not significantly change the coefficients.

A randomised, double-blind, parallel design, multi-institutional, non-inferiority phase IV trial of imidafenacin versus fesoterodine for overactive bladder.

Our objective was to compare the efficacy and safety of imidafenacin over fesoterodine in patients with overactive bladder (OAB).

Rate and associated factors of solifenacin add-on after tamsulosin monotherapy in men with voiding and storage lower urinary tract symptoms

To explore the rate of add‐on therapy with solifenacin in men with voiding and storage lower urinary tract symptoms (LUTS) after tamsulosin monotherapy and to explore predictive factors for starting solifenacin add‐on therapy.

Persistence of solifenacin therapy in patients with overactive bladder in the clinical setting: a prospective, multicenter, observational study

The aim of this study was to evaluate the persistence with solifenacin therapy over a 12‐month period in patients with overactive bladder (OAB).

A randomised, prospective double-blind, propiverine-controlled trial of imidafenacin in patients with overactive bladder

To assess the efficacy and safety of imidafenacin compared with propiverine for treatment of overactive bladder (OAB) in Korean patients.

Does hard core interaction change absorbing-type critical phenomena?

It has been generally believed that hard core interaction is irrelevant to absorbing-type critical phenomena because the particle density is so low near an absorbing phase transition. We study the effect of hard core interaction on the N-species branching annihilating random walks with two offspring and report that hard core interaction drastically changes the absorbing-type critical phenomena in a nontrivial way. Through a Langevin equation-type approach, we predict analytically the values of the scaling exponents, nu( perpendicular) = 2, z = 2, alpha = 1/2, and beta = 2 in one dimension for all N>1. Direct numerical simulations confirm our prediction. When the diffusion coefficients for different species are not identical, nu( perpendicular) and beta vary continuously with the ratios between the coefficients.

Molecular Characteristics of Subterranean Termites of the genus Reticulitermes (Isoptera: Rhinotermitidae) From Korea

ABSTRACT Molecular and taxonomic studies of subterranean termites in the genus Reticulitermes (Isoptera: Rhinotermitidae) have suggested that Reticulitermes speratus kyushuensis Morimoto is the only species that occurs in Korea. However, the specimens studied to date were collected from a limited number of locations, and basic information about the distribution, taxonomy, and molecular characteristics of this genus in Korea is still lacking. In this study, we collected Reticulitermes specimens from 50 sampling sites distributed throughout the country. By comparing the cytochrome oxidase subunit II gene of mitochondrial DNA sequences, we conclude that Reticulitermes speratus is represented by two haplotypes in Korea. In addition, we report the first occurrence of another Reticulitermes species in this country.

Persistence with solifenacin add‐on therapy in men with benign prostate obstruction and residual symptoms of overactive bladder after tamsulosin monotherapy

In spite of the reported efficacy and safety of antimuscarinics in men with OAB (overactive bladder) and BPO (benign prostatic obstruction), many patients do not persist with the treatment. We aimed to evaluate persistence and the reasons for the discontinuation of solifenacin add‐on therapy in men with residual symptoms of OAB after tamsulosin monotherapy for BPO in a real clinical environment.