oint friction is one of the major limitations in performing high J precision manipulation tasks. It affects both static and dynamic performances, and may cause instability when coupled to position or force feedback control. Thus, compensating for joint friction has been one of the main research issues in robot design and control over the years. The aim of this paper is to show how friction comp...

A model of semiflexible bead-rod chain with anisotropic friction can mimic closely the hydrodynamics of a slender filament. We present an efficient algorithm for Brownian dynamics simulations of this model with configuration dependent anisotropic bead friction coefficients. The algorithm is an extension of that given previously for the case of configuration independent isotropic friction coeffi...

Following a recession, the aggregate labor market is slack—employment remains below normal and recruiting efforts of employers, as measured by vacancies, are low. A model of matching frictions explains the qualitative responses of the labor market to adverse shocks, but requires implausibly large shocks to account for the magnitude of observed fluctuations. The incorporation of wage-setting fri...

At the mesoscale friction occurs through the breaking and formation of local contacts. This is often described by the earthquake-like model which requires numerical studies. We show that this phenomenon can also be described by a master equation, which can be solved analytically in some cases and provides an efficient numerical solution for more general cases. We examine the effect of temperatu...

A cake is a metaphor for a heterogeneous, divisible good, such as land. A perfect division of cake is efficient (also called Pareto-optimal), envyfree, and equitable. We give an example of a cake in which it is impossible to divide it among three players such that these three properties are satisfied, however many cuts are made. It turns out that two of the three properties can be satisfied by ...

Fair Division, unlike most research on fairness in the social sciences and mathematics, is devoted solely to the analysis of constructive procedures for actually dividing things up and resolving disputes, including...

Viscoelastic liquids with very small amounts of polymer/surfactant additives can, as well known since B.A. Toms’ observation in 1948, provide substantial reductions in frictional drag of wall-bounded turbulence relative to the corresponding Newtonian fluid flow. Friction reductions of up to 80% compared to the pure water flow can be occasionally achieved with smooth channel/pipe flow of viscoel...

An efficient scheme is presented for the numerical calculation of hydrodynamic interactions of many spheres in Stokes flow. The spheres may have various sizes, and are freely moving or arranged in rigid arrays. Both the friction and mobility matrix are found from the solution of a set of coupled equations. The Stokesian dynamics of many spheres and the friction and mobility tensors of polymers ...

At the mesoscale friction occurs through the breaking and formation of local contacts. This is often described by the earthquakelike model which requires numerical studies. We show that this phenomenon can also be described by a master equation, which can be solved analytically in some cases and provides an efficient numerical solution for more general cases. We examine the effect of temperatur...

A new friction powder compaction (FPC) process is introduced for compacting commercially pure titanium powder. The FPC process is very simple and energy-efficient since it requires only a rotating tool plunged into an aluminum plate with a hole filled with titanium powder, and no external heat source is necessary. The sintering of the powder is mainly achieved by the friction heat and pressing ...