773 research outputs found
On Talagrand's functional and generic chaining
In the study of the supremum of stochastic processes, Talagrand's chaining
functionals and his generic chaining method are heavily related to the
distribution of stochastic processes. In the present paper, we construct
Talagrand's type functionals in the general distribution case and obtain the
upper bound for the suprema of all -th moments of the stochastic process
using the generic chaining method. As applications, we obtained the
Johnson-Lindenstrauss lemma, the upper bound for the supremum of all -th
moment of order 2 Gaussian chaos, and convex signal recovery in our setting
Ride-matching and routing optimisation: Models and a large neighbourhood search heuristic
This paper considers a ridesharing problem on how to match riders to drivers and how to choose the best routes for vehicles. Unlike the others in the literature, we are concerned with the maximization of the average loading ratio of the entire system. Moreover, we develop a flow-dependent version of the model to characterize the impact of pick-up and drop-off congestion. In another extended model we take into account the riders’ individual evaluation on different transportation modes. Due to the large size of the resulting models, we develop a large neighbourhood search algorithm and demonstrate its efficiency
Comprehensive Demonstration of Spin-Hall Hanle Effects in Epitaxial Pt Thin Films
We demonstrate a nonlinear Hall effect due to the boundary spin accumulation
in Pt films grown on Al2O3 substrates. This Hall effect and the previously
demonstrated Hanle magnetoresistance provide a complete picture of the
spin-precession control of the spin and charge transport at the boundary of a
spin-orbit coupled material, which we refer to as spin-Hall Hanle effects
(SHHE). We also show that the SHHE can be employed to measure the spin
diffusion length, the spin-Hall angle, and the spin relaxation time of heavy
metal without the need of magnetic interface or the input from other
measurements. The comprehensive demonstration of SHHE in such a simple system
suggests they may be ubiquitous and needs to be considered for unravelling the
spin and charge transport in more complex thin film structures of spin-orbit
coupled materials
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