In Pawlak’s rough set theory, a set is approximated by a pair of lower and upper approximations. To measure numerically the roughness of an approximation, Pawlak introduced a quantitative measure of roughness by using the ratio of the cardinalities of the lower and upper approximations. Although the roughness measure is effective, it has the drawback of not being strictly monotonic with respect...

Modern wind turbines usually suffer unexpected power losses after long operating periods due to the contaminations accumulated at the leading edge of blades. In order to investigate the underlying physics, experiments were conducted to study the performance degradation of low-Reynolds-number airfoils induced by distributed leading edge roughness. Roughness was simulated by precisely manufacture...

MHD effect using micropolar fluid between rough conical bearings is analyzed in this paper. The Reynolds equation derived the form of magnetic field Eringen principle with Christensen theory. stochastic modified for two types one-dimensional structure, radial roughness pattern and azimuthal patterns fluid. In terms dimensionless pressure, load carrying capacity time, numerical results are prese...

If the nominal contact tractions at an interface are everywhere below the Coulomb friction limit throughout a cycle of oscillatory loading, the introduction of surface roughness will generally cause local microslip between the contacting asperities and hence some frictional dissipation. This dissipation is important both as a source of structural damping and as an indicator of potential frettin...

Surface acoustic wave (SAW) velocity spectroscopy has been long considered to be one of the leading candidates for nondestructive characterization of surface-treated metals because of its ability to probe the material properties at different penetration depths depending on the inspection frequency. We developed a high-precision laser-ultrasonic technique to study the feasibility of SAW dispersi...

Electro-discharge machining (EDM) is increasingly being used in many industries for producing molds and dies, and machining complex shapes with material such as steel, cemented carbide, and engineering ceramics. The stochastic nature of EDM process has frustrated number of attempts to model it physically. Artificial neural networks (ANNs), as one of the most attractive branches in Artificial In...

Traditional measures of dysphonia vary in their reliability and in their correlations with perceptions of grade. Measurements of cepstral peak prominence (CPP) have been shown to correlate well with perceptions of breathiness. Because it is a measure of periodicity, CPP should also predict roughness. The ability of CPP and other acoustic measures to predict overall dysphonia and the subcategori...

In this paper we present an investigation into visually perceived surface roughness. First we present psychophysical evidence that suggests that there is a simple relationship between perceived roughness and two well known surface parameters: fractal dimension and rms roughness. And that neither are good estimators, on there own, of perceived roughness. Second we present a measurement model for...

background: an increase in surface roughness of ceramics may decrease strength and affect the clinical success of ceramic restorations. however, little is known about the effect of acidic agents on ceramic restorations. the aim of this study was to evaluate the surface roughness of dental ceramics after being immersed in acidic agents.     methods: eighty-three ceramic disk specimens (12.0 mm i...

Shallow waters influence the behaviour and performance of a vessel by modifying local pressure distribution, wave making, boundary layer thickness. The thickness is also influenced surface roughness. No previous studies have investigated combined effects shallow water contributions roughness on ship resistance. This study aims to fill this knowledge gap in literature using Unsteady Reynolds Ave...