This paper describes a system in which multiple robots cooperate to move multiple objects such as groups of boxes using a constrained prehensile manipulation mode, by wrapping ropes around them. The system consists of three manipulation skills: tieing ropes around objects, affecting rotations using a flossing manipulation gait, and affecting translations using a ratcheting manipulation gait. We...

We study the problem of optimal dividend payout from a surplus process governed by Brownian motion with drift under additional constraint ratcheting, i.e., rate can never decrease. solve resulting two-dimensional control problem, identifying value function to be unique viscosity solution corresponding Hamilton--Jacobi--Bellman equation. For finitely many admissible rates we prove that threshold...

ÐTransformation superplasticity of an intermetallic Ti3Al-based alloy (Super a2) is demonstrated by thermal cycling about the a2/b transformation temperature range under a uniaxial tensile biasing stress. Failure strains up to 610% were recorded at a stress of 3 MPa, compared with 110% for deformation by isothermal creep at the same stress. The strain increment produced during each half-cycle i...

This paper studies finite horizon portfolio management by optimally tracking a ratcheting capital benchmark process. It is assumed that the fund manager can dynamically inject into account such total dominates nondecreasing floor process at each intermediate time. The problem formulated to minimize cost of accumulated injection. We first transform original with constraints an unconstrained cont...

Many animals have socially transmitted behavioural traditions, but human culture appears unique in that it is cumulative, i.e. human cultural traits increase in diversity and complexity over time. It is often suggested that high-fidelity cultural transmission is necessary for cumulative culture to occur through refinement, a process known as 'ratcheting', but this hypothesis has never been form...