5,657 research outputs found
Single-domain versus two-domain configuration in thin ferromagnetic prisms
Thin ferromagnetic elements in the form of rectangular prisms are
theoretically investigated in order to study the transition from single-domain
to two-domain state, with changing the in-plane aspect ratio p. We address two
main questions: first, how general is the transition; second, how the critical
value p_c depends on the physical parameters. We use two complementary methods:
discrete-lattice calculations and a micromagnetic continuum approach. Ultrathin
films do not appear to split in two domains. Instead, thicker films may undergo
the above transition. We have used the continuum approach to analyze recent
Magnetic Force Microscopy observations in 30 nm-thick patterned Permalloy
elements, finding a good agreement for p_c.Comment: 22 pages, 5 figure
Towards String-to-Tree Neural Machine Translation
We present a simple method to incorporate syntactic information about the
target language in a neural machine translation system by translating into
linearized, lexicalized constituency trees. An experiment on the WMT16
German-English news translation task resulted in an improved BLEU score when
compared to a syntax-agnostic NMT baseline trained on the same dataset. An
analysis of the translations from the syntax-aware system shows that it
performs more reordering during translation in comparison to the baseline. A
small-scale human evaluation also showed an advantage to the syntax-aware
system.Comment: Accepted as a short paper in ACL 201
Rainbow sets in the intersection of two matroids
Given sets , a {\em partial rainbow function} is a partial
choice function of the sets . A {\em partial rainbow set} is the range of
a partial rainbow function. Aharoni and Berger \cite{AhBer} conjectured that if
and are matroids on the same ground set, and are
pairwise disjoint sets of size belonging to , then there exists a
rainbow set of size belonging to . Following an idea of
Woolbright and Brower-de Vries-Wieringa, we prove that there exists such a
rainbow set of size at least
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