A new crane design, labeled ”SpiderCrane”, is proposed to handle fast load displacements. Its main particularity is the absence of heavy mobile components. The system beeing underactuated, its control is challenging. Hence, as a step towards easier and more efficient control, this paper proposes a dynamic model and investigates the two control-relevant properties of flatness and observability. ...

We discuss in some detail the requirements on an early-Universe model that solves the horizon and flatness problems during the epoch of classical cosmology (t ≥ ti ≫ 10 sec). We show that a dynamical resolution of the horizon problem requires superluminal expansion (or very close to it) and that a truly satisfactory resolution of the flatness problem requires entropy production. This implies th...

Differential flatness is a property which substantially reduces the difficulty involved in generating dynamically feasible trajectories for underactuated robotic systems. However, there is a large class of robotic systems that are not differentially flat, and an efficient method for computing dynamically feasible trajectories does not exist. In this paper we introduce a weaker but more general ...

We investigate experimentally the dependence of the Goos-Hänchen shift on the surface properties of an air-metal interface. The shift depends on the microscopic roughness of the metal surface but it is insensitive to the large-scale variations associated with surface non-flatness. Both an effective medium model of roughness and the Rayleigh-Rice theory of scattering are used to interpret the ob...

Abstract. This paper is devoted to the study of rigidity properties for special solutions of nonlinear elliptic partial differential equations on smooth, boundaryless Riemannian manifolds. As far as stable solutions are concerned, we derive a new weighted Poincaré inequality which allows to prove Liouville type results and the flatness of the level sets of the solution in dimension 2, under sui...

Advanced seismic techniques such as prestack inversion or azimuthal analysis are now routinely adopted for quantitative reservoir characterization of rock properties and fracture indicators, however the quality of the input seismic data is critical to such advanced analyses. Frequency content, random and coherent noise, amplitude-preserving processing and gather flatness must be addressed at th...

Strong flatness properties are established for a large class of functional-analytic rings including all C*-algebras. This is later used to prove that all those rings satisfy excision in Hochschild and in cyclic homology over almost arbitrary rings of coefficients and that, for stable C*-algebras, the Hochschild and cyclic homology groups defined over an arbitrary coefficient ring k subset C of ...