Flexible sliced designs for computer experiments

Sliced Latin hypercube designs are popularly adopted for computer experiments with qualitative factors. Previous constructions require the sizes of different slices to be identical. Here we construct sliced designs with flexible sizes of slices. Besides achieving desirable one-dimensional uniformity, flexible sliced designs (FSDs) constructed in this paper accommodate arbitrary sizes for different slices and cover ordinary sliced Latin hypercube designs as special cases. The sampling properties of FSDs are derived and a central limit theorem is established. It shows that any linear combination of the sample means from different models on slices follows an asymptotic normal distribution. Some simulations compare FSDs with other sliced designs in collective evaluations of multiple computer models.     

Transient heating effects in electromagnetic launchers with complex geometries: A 3D hybrid FE/BE analysis

A time-stepping finite-element (FE) and boundary-element (BE) coupling method was implemented to include 3D transient eddy current under electromagnetic heating effects in electromagnetic launchers. Lagrangian formulations were used to model electromagnetic and thermal diffusive processes with moving conductors. The finite-element formulation was employed for the general diffusion equation in a bounded conductor region including rail and armature; while, in the exterior region, the boundary element method was developed for Laplace's equation. The coupled boundary was employed directly on the surface of conductors and no special treatment on boundary was required. The electromagnetic and temperature fields were coupled through iterative calculations. This method results in considerable time saving in modeling as it eliminates the surrounding air region.     

Exact Meromorphic Stationary Solutions of the Real Cubic Swift‐Hohenberg Equation

We show that all meromorphic solutions of the stationary reduction of the real cubic Swift‐Hohenberg equation are elliptic or degenerate elliptic. We then obtain them all explicitly by the subequation method, and one of them appears to be a new elliptic solution.     

Synthesis and multiple reuse of eccentric Au@TiO2 nanostructures as catalysts

In this work, we have synthesized eccentric Au@TiO(2) core-shell nanostructures and demonstrated their multiple reuse in the catalytic reduction of 4-nitrophenol.