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.