10,574 research outputs found
Persistence and Memory in Patchwork Dynamics for Glassy Models
Slow dynamics in disordered materials prohibits direct simulation of their
rich nonequilibrium behavior at large scales. "Patchwork dynamics" is
introduced to mimic relaxation over a very broad range of time scales by
equilibrating or optimizing directly on successive length scales. This dynamics
is used to study coarsening and to replicate memory effects for spin glasses
and random ferromagnets. It is also used to find, with high confidence, exact
ground states in large or toroidal samples.Comment: 4 pages, 4 figures; reference correctio
Reply to Comment on "Triviality of the Ground State Structure in Ising Spin Glasses"
We reply to the comment of Marinari and Parisi [cond-mat/0002457 v2] on our
paper [Phys. Rev. Lett. 83, 5126 (1999) and cond-mat/9906323]. We show that the
data in the comment are affected by strong finite-size corrections. Therefore
the original conclusion of our paper still stands.Comment: Reply to comment cond-mat/0002457 on cond-mat/9906323. Final version
with minor change
Identifying key challenges and needs in digital mental health moderation practices supporting users exhibiting risk behaviours to develop responsible AI tools: the case study of Kooth.
Digital platforms for mental health and wellbeing purposes have become increasingly common to help users exhibiting risk behaviours (e.g. self-harming, eating-related disorders) across all ages, opening new frontiers in supporting vulnerable users. This study stems from a larger project, which explores how responsible AI solutions can up-scale existing manual moderation approaches and better target interventions for young people who ask for help or engage in risk behaviours online. This research aims to better understand the challenges and needs of moderators and digital counsellors, i.e. the ‘behind the scenes’. Through this case study, the authors intend to contribute to the development of responsible AI tools that are ft for purpose and better understand the challenges. The key focus lies on Kooth.com, the UK’s leading free online confdential service offering counselling and emotional wellbeing support to young people in the UK through its online web-based and pseudo-anonymous digital platform
Crew Motion and the Dynamic Environment of Spaceborne Experiments
Analytical study of crew motion on dynamic environment of orbiting laboratorie
Ground-State Roughness of the Disordered Substrate and Flux Line in d=2
We apply optimization algorithms to the problem of finding ground states for
crystalline surfaces and flux lines arrays in presence of disorder. The
algorithms provide ground states in polynomial time, which provides for a more
precise study of the interface widths than from Monte Carlo simulations at
finite temperature. Using systems up to size , with a minimum of
realizations at each size, we find very strong evidence for a
super-rough state at low temperatures.Comment: 10 pages, 3 PS figures, to appear in PR
Hysterectomy, endometrial ablation, and levonorgestrel releasing intrauterine system (Mirena) for treatment of heavy menstrual bleeding : cost effectiveness analysis
Peer reviewedPublisher PD
Modelling the tongue-of-ionisation using CTIP with SuperDARN electric potential input: verification by radiotomography
Electric potential patterns obtained by the SuperDARN radar network are used as input to the Coupled Thermosphere-Ionosphere-Plasmasphere model, in an attempt to improve the modelling of the spatial distribution of the ionospheric plasma at high latitudes. Two case studies are considered, one under conditions of stable IMF <I>B<sub>z</sub></I> negative and the other under stable IMF <I>B<sub>z</sub></I> positive. The modelled plasma distributions are compared with sets of well-established tomographic reconstructions, which have been interpreted previously in multi-instrument studies. For IMF <I>B<sub>z</sub></I> negative both the model and observations show a tongue-of-ionisation on the nightside, with good agreement between the electron density and location of the tongue. Under <I>B<sub>z</sub></I> positive, the SuperDARN input allows the model to reproduce a spatial plasma distribution akin to that observed. In this case plasma, unable to penetrate the polar cap boundary into the polar cap, is drawn by the convective flow in a tongue-of-ionisation around the periphery of the polar cap
Spin and link overlaps in 3-dimensional spin glasses
Excitations of three-dimensional spin glasses are computed numerically. We
find that one can flip a finite fraction of an LxLxL lattice with an O(1)
energy cost, confirming the mean field picture of a non-trivial spin overlap
distribution P(q). These low energy excitations are not domain-wall-like,
rather they are topologically non-trivial and they reach out to the boundaries
of the lattice. Their surface to volume ratios decrease as L increases and may
asymptotically go to zero. If so, link and window overlaps between the ground
state and these excited states become ``trivial''.Comment: Extra fits comparing TNT to mean field, summarized in a tabl
Measuring functional renormalization group fixed-point functions for pinned manifolds
Exact numerical minimization of interface energies is used to test the
functional renormalization group (FRG) analysis for interfaces pinned by
quenched disorder. The fixed-point function R(u) (the correlator of the
coarse-grained disorder) is computed. In dimensions D=d+1, a linear cusp in
R''(u) is confirmed for random bond (d=1,2,3), random field (d=0,2,3), and
periodic (d=2,3) disorders. The functional shocks that lead to this cusp are
seen. Small, but significant, deviations from 1-loop FRG results are compared
to 2-loop corrections. The cross-correlation for two copies of disorder is
compared with a recent FRG study of chaos.Comment: 4 pages, 4 figure
- …