5,080 research outputs found
Kinetic self-organization of trenched templates for the fabrication of versatile ferromagnetic nanowires
We have self-organized versatile magnetic nanowires, ie with variable period
and adjustable magnetic anisotropy energy (MAE). First, using the kinetic
roughening of W(110) uniaxial templates of trenches were grown on commercial
Sapphire wafers. Unlike most templates used for self-organization, those have a
variable period, 4-12nm are demonstrated here. Fe deposition then results in
the formation of wires in the trenches. The magnitude of MAE could be
engineered up or down by changing the capping- or underlayer, in turn affecting
the mean superparamagnetic temperature, raised to 175K so far.Comment: 3 page
Multivariate sparse clustering for extremes
Identifying directions where extreme events occur is a major challenge in
multivariate extreme value analysis. In this paper, we use the concept of
sparse regular variation introduced by Meyer and Wintenberger to infer the tail
dependence of a random vector X. This approach relies on the Euclidean
projection onto the simplex which better exhibits the sparsity structure of the
tail of X than the standard methods. Our procedure based on a rigorous
methodology aims at capturing clusters of extremal coordinates of X. It also
includes the identification of a threshold above which the values taken by X
are considered as extreme. We provide an efficient and scalable algorithm
called MUSCLE and apply it on numerical experiments to highlight the relevance
of our findings. Finally we illustrate our approach with wind speed data and
financial return data
Heat Transfer in the Transitional Flow Regime
http://www.intechopen.com/articles/show/title/heat-transfer-in-the-transitional-flow-regim
Magnetic properties of self-organized lateral arrays of (Fe,Ag)/Mo(110) nanostripes
We report the fabrication of self-organized arrays of Fe nanostripes with a
period of 3.5 nm, by sequential deposition of Fe and Ag on Mo(110). The wires
display a strong in-plane uniaxial anisotropy along their length, and are
superparamagnetic above Tb=185+/-15K. The large value of nucleation volumes,
inferred from the analysis of the thermal dependence of coercivity below TB,
suggests the existence of interactions between the wires.Comment: 3 pages journal-style Proceedings of MMM0
Place sequence learning for navigation
Abstract. A model of the hippocampus as a \cognitive map", inspired by the models of Burgess et al. (1994) and Jensen et al. (1996), is proposed. Simulations show that the resulting navigation behavior is as e-cient as the behavior exhibited by previous models. However, the architecture of the proposed model and the mechanisms governing the temporal characteristics of the neurons in the model are more realistic. In particular, the proposed model assigns distinct and speci c roles to the entorhinal cortex, the dentate gyrus and the hippocampal CA3 region. In essence, the dentate gyrus could act as a short-term memory that maintains the representation of a sequence of recently visited places. It could then force the corresponding CA3 place cells to re and to learn the spatial relationships between places through a Hebbian rule. This \topological representation " could then serve as a basis for predicting places ahead of the animal and drive \goal cells", i.e. cells that represent the direction to the goal, as proposed by Burgess et al.
From SG for crime scene coordination to a reflexion about the roles of images in police activity
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