To describe the heterogeneous nature of stress transmission in granular materials, the concept of the "strong" network consisting of contacts with large normal forces has been proposed by Radjaï [Phys. Rev. Lett. 80, 61 (1998)]. The shear stress is mainly determined by this strong network. The dual viewpoint is adopted here, by not only considering the forces at contacts, but also the deformati...

Spherical cameras are variable-resolution imaging systems and promising devices for autonomous navigation purposes, mainly because of their wide viewing angle which increases the capabilities of vision-based obstacle avoidance schemes. In addition, spherical lenses resemble the primate eye in their projective models and are biologically relevant. However, the calibration of spherical lenses for...

It is generally assumed that sensitivity to different stimulus orientations is mapped in a globally equivalent fashion across primate visual cortex, at a spatial scale larger than that of orientation columns. However, some evidence predicts instead that radial orientations should produce higher activity than other orientations, throughout visual cortex. Here, this radial orientation bias was ro...

In this paper, new robust algorithms for the solution of systems of linear equations which arise from the discretisation of partial diierential equations with strongly varying coeecients are introduced. These iterative methods are based on the tangential frequency ltering decompositions. The existence of the TFFD and the convergence of the induced iterative algorithms is shown for symmetric and...

The elastocapillary instability of a flexible plate plunged in a liquid bath is analyzed theoretically. We show that the plate can bend due to two separate destabilizing mechanisms, when the liquid is partially wetting the solid. For contact angles θ(e) > π/2, the capillary forces acting tangential to the surface are compressing the plate and can induce a classical buckling instability. However...

The influence of structural defects, in the form of step lattices, on the spin polarization of the spin-orbit split Shockley surface state of Au(111) has been investigated. Spin- and angle-resolved photoemission data from three vicinal surfaces with different step densities are presented. The spin splitting is preserved in all three cases, and there is no reduction of the spin polarization of i...

Designing aesthetically appealing models is vital for the marketing success of industrial products. In this paper, we propose quasi-Aesthetic Curves that can be used in CAD systems for aesthetic shape design. Quasi-Aesthetic Curves represented in rational cubic Bézier Forms are curves whose logarithmic curvature histograms (LCHs) become nearly straight lines. The monotonicity of curvature of qu...

the metal sheets play an important role in the mechanical design, particularly in the aerospace structures. the rivet connections are frequently used to connect these sheets. the riveting quality greatly influences the rupture of the rivet and the sheet. the various parameters affect the quality of this operation. in this paper, the optimization of the parameters contributing to the riveting qu...

Abstract-A solution to the equations of elastic equilibrium is developed in terms of two harmonic functions, such that on a certain plane, normal stresses are identically zero, whilst tangential stresses and displacements are expressible as simple derivatives. The solution is used to solve the problem of the penny-shaped crack subjected to an arbitrary tangential traction and the corresponding ...

We present a new numerical method for solving two-dimensional Stokes flow with deformable interfaces such as dynamics of suspended drops or bubbles. The method is based on a boundary integral formulation for the interfacial velocity and is spectrally accurate in space. We analyze the singular behavior of the integrals (single-layer and double-layer integrals) appearing in the equations. The int...