Attaining animal-like legged locomotion on rough outdoor terrain with sparse foothold affordances — a primary use-case for legs vs other forms of locomotion — is a largely open problem. New advancements in control and perception have enabled bipeds to walk on flat and uneven indoor environments. But tasks that require reliable contact with unstructured world surfaces, for example walking on nat...

Implicit surface techniques provide useful tools for modeling and rendering smooth surfaces. Deriving implicit formulations for fractal representations extends the scope of implicit surface techniques to rough surfaces. Linear fractals modeled by recurrent iterated function systems may be de ned implicitly using either geometric distance or escape time. Random fractals modeled using Perlin's no...

A new method for investigation of X-ray beam propagation in a rough narrow dielectrical waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface is used with the given distribution of hights of roughness and given correlation properties of the surface. The method is free from the limitations such as infiniteness of the s...

The Reynolds number dependence of turbulent channel flow over two irregular rough surfaces, based on scans of a graphite and a gritblasted surface, is studied by direct numerical simulation. The aim is to characterise the changes in the flow in the immediate vicinity of and within the rough surfaces, an area of the flow where it is difficult to obtain experimental measurements. The average roug...

The scattering of waves by a buried object is often obscured by the clutter around it. Such clutter can be attributed to the scattering by random rough surfaces and random discrete scatterers. Recent studies show that, because of the memory effect, the angular correlation function can suppress the effects of clutter and make the scattering by the buried object more conspicuous. In this paper, w...

─ This paper presents an investigation into the electromagnetic scattering characteristic of two-dimensional (2-D) layered rough surfaces by using a finite-difference time-domain (FDTD) algorithm, which constitutes a three-dimensional scattering problem. The uniaxial perfectly matched layer medium is adopted for truncation of FDTD lattices, in which the finite-difference equations can be used f...

Implicit surface techniques provide useful tools for modeling and rendering smooth surfaces. Deriving implicit formulations for fractal representations extends the scope of implicit surface techniques to rough surfaces. Linear fractals modeled by recurrent iterated function systems may be deened implicitly using either geometric distance or escape time. Random fractals modeled using Perlin's no...

The effects of volume scattering and rough-surface scattering in passive microwave remote sensing are treated. The volumescattering model is based on dense medium radiative transfer (DMRT) theory with quasicrystalline approximation (QCA) for densely distributed sticky particles. The rough-surface bistatic scattering and emission are modeled using the numerical Maxwell model of 3D simulations (N...

The effect of roughness on the dewetting behavior of polyethylene thin films on silicon dioxide substrates is presented. Smooth and rough silicon dioxide substrates of 0.3 and 3.2-3.9 nm root-mean-square roughness were prepared by thermal oxidation of silicon wafers and plasma-enhanced chemical vapor deposition on silicon wafers, respectively. Polymer thin films of approximately 80 nm thickness...

Natural grounds can exhibit small geometry irregularities, compared to the wavelength, which are called surface roughness. Using effective impedance is a useful way to model the effects of surface roughness on outdoor sound propagation, particularly in numerical methods as it avoids the meshing of small irregularities. In this paper, firstly an effective impedance model taking into account the ...