In this paper protraction movement, namely stepping ahead, of a three joint robot leg is optimized for energy efficiency for any given pair of initial-final tip point positions. For the optimization a modified version of gradient descent based optimal control algorithm with Hamiltonian formulation is used. The objective function is modified in steps to jump over the infeasible and inefficient l...

When body-centered-cubic crystals undergo plastic deformation, the slip planes are often noncrystallographic. By performing atomistic simulation on the activation pathway of dislocation jumps in bcc iron, we show that the main reason for bcc crystals to exhibit this phenomenon is that one type of kink pair has significantly lower energy than all the other types on the same slip plane. Dislocati...

When a vector field in R is discontinuous on a smooth codimension one surface, it may be simultaneously tangent to both sides of the surface at generic isolated points (singularities). For a piecewise-smooth dynamical system governed by the vector field, we show that the local dynamics depends on a single quantity—the jump in direction of the vector field through the singularity. This quantity ...

This paper reports the three-dimensional (3D) generalization of our previous 2D higher-order matched interface and boundary (MIB) method for solving elliptic equations with discontinuous coefficients and non-smooth interfaces. New MIB algorithms that make use of two sets of interface jump conditions are proposed to remove the critical acute angle constraint of our earlier MIB scheme for treatin...

Neuromorphic computing embraces the “device history” offered by many analog non-volatile memory (NVM) devices to implement the small weight changes computed by a gradient-descent learning algorithm such as backpropagation. Deterministic and stochastic imperfections in the conductance response of real NVM devices can be encapsulated for modeling within a pair of “jump-tables.” Such jump-tables d...

We are concerned with the long-time asymptotic behavior of solution for focusing Hirota equation (also called third-order nonlinear Schrödinger equation) symmetric, non-zero boundary conditions (NZBCs) at infinity. Firstly, based on Lax pair NZBCs, direct and inverse scattering problems used to establish oscillatory Riemann-Hilbert (RH) problem distinct jump curves. Secondly, Deift-Zhou steepes...