4,172,214 research outputs found
Recent Results from the SIMPLE Dark Matter Search
SIMPLE is an experimental search for evidence of spin-dependent dark matter,
based on superheated droplet detectors using CClF. We report
preliminary results of a 0.6 kgdy exposure of five one liter devices, each
containing 10 g active mass, in the 1500 mwe LSBB (Rustrel, France). In
combination with improvements in detector sensitivity, the results exclude a
WIMP--proton interaction above 5 pb at M = 50 GeV/c.Comment: 6 pages, 2 figures,contribution to IDM2004, Sept. 6-10, 2004,
Edinburgh, U
Uncovering missing links with cold ends
To evaluate the performance of prediction of missing links, the known data
are randomly divided into two parts, the training set and the probe set. We
argue that this straightforward and standard method may lead to terrible bias,
since in real biological and information networks, missing links are more
likely to be links connecting low-degree nodes. We therefore study how to
uncover missing links with low-degree nodes, namely links in the probe set are
of lower degree products than a random sampling. Experimental analysis on ten
local similarity indices and four disparate real networks reveals a surprising
result that the Leicht-Holme-Newman index [E. A. Leicht, P. Holme, and M. E. J.
Newman, Phys. Rev. E 73, 026120 (2006)] performs the best, although it was
known to be one of the worst indices if the probe set is a random sampling of
all links. We further propose an parameter-dependent index, which considerably
improves the prediction accuracy. Finally, we show the relevance of the
proposed index on three real sampling methods.Comment: 16 pages, 5 figures, 6 table
Hymn to the heroes of Malta
Ä abra taâ poeĆŒiji u proĆŒa li tinkludi: Alla fil-ħolqien taâ Ä uĆŒĂš Agius Bonello â Is-sena u l-bniedem taâ Ä uĆŒĂš Ellul-Mercer â Li tiĆŒraâ taħsad taâ Vic. Apap â Huwa taâ Gino Muscat-Azzopardi â Ć»ewÄĄ friefet taâ Vincent Caruana â IÄ-Äagħka taâ Ä uĆŒĂš Borg â Warda midbiela taâ C. Gauci â It-tfajla tas-sulfarini taâ Albert M. Cassola â L-aħħar traduzzjoni taâ May Butcher qabel ma mietet â Hymn to the heroes of Malta.N/
Three-Valued Modal Logic for Qualitative Comparative Policy Analysis with Crisp-Set QCA
Contradictory and missing outcomes are problems common to many qualitative comparative studies, based on the methodology of crisp-set QCA. They also occur in public policy analyses, e.g. if important background variables are omitted or outcomes of new policies are technically censored. As a new solution to these problems, this article proposes the use of three-valued modal logic, originally introduced by the Polish philosopher Jan Lukasiewicz (1970). In addition to true and false, indeterminate is the third truth-value in this alternative approach, which serves to code missing or contradictory data. Moreover, modal operators allow a differentiation between strict and possible triggers and inhibitors of policy outcomes. The advantages of three-valued modal logic in crisp-set QCA are illustrated by an empirical example from comparative welfare policy analysis. Its conclusions allow comparisons with the corresponding results from a conventional crisp-set QCA of the same data-set
LETS get real: constraints on the development of Local Exchange Trading Schemes
Local Exchange Trading Schemes (LETS) are widely promoted as a new tool for local economic development, but until recently the focus has been on their alleged âpotentialâ rather than the realities of their operation. This paper assesses the practical economic role of LETS by examining the amount of trading conducted, and demonstrates that both the volume of trading and the value of the trades are very low. Drawing on an intensive case study of the first UK LETS created explicitly as part of a local authorityâs anti-poverty strategy, explanations for the low levels of participation are suggested, and significant structural constraints on the development of LETS are identified
Buffer influence on magnetic dead layer, critical current and thermal stability in magnetic tunnel junctions with perpendicular magnetic anisotropy
We present a thorough research on Ta/Ru-based buffers and their influence on
features crucial from the point of view of applications of MTJs, such as
critical switching current and thermal stability. We investigate devices
consisting of buffer/FeCoB/MgO/FeCoB/Ta/Ru multilayers for three different
buffers: Ta 5 / Ru 10 / Ta 3, Ta 5 / Ru 10 / Ta 10 and Ta 5 / Ru 20 / Ta 5 (all
thicknesses in nm). In addition, we study systems with a single FeCoB layer
deposited above as well as below the MgO barrier. The crystallographic texture
and the roughness of the buffers are determined by means of XRD and atomic
force microscopy measurements. Furthermore, we examine the magnetic domain
pattern, the magnetic dead layer thickness and the perpendicular magnetic
anisotropy fields for each sample. Finally, we investigate the effect of the
current induced magnetization switching for nanopillar junctions with lateral
dimensions ranging from 1 {\mu}m down to 140 nm. Buffer Ta 5 / Ru 10 / Ta 3,
which has the thickest dead layer, exhibits a large increase in the thermal
stability factor while featuring a slightly lower critical current density
value when compared to the buffer with the thinnest dead layer Ta 5 / Ru 20 /
Ta 5
Controlling the near-surface superfluid density in underdoped YBaâCuâO<sub>6+<i>x</i></sub> by photo-illumination
The interaction with light weakens the superconducting ground state in classical superconductors. The situation in cuprate superconductors is more complicated: illumination increases the charge carrier density, a photo-induced effect that persists below room temperature. Furthermore, systematic investigations in underdoped YBaâCuâO6+x (YBCO) have shown an enhanced critical temperature Tc. Until now, studies of photo-persistent conductivity (PPC) have been limited to investigations of structural and transport properties, as well as the onset of superconductivity. Here we show how changes in the magnetic screening profile of YBCO in the Meissner state due to PPC can be determined on a nanometer scale utilizing low-energy muons. The data obtained reveal a strongly increased superfluid density within the first few tens of nanometers from the sample surface. Our findings suggest a non-trivial modification of the near-surface band structure and give direct evidence that the superfluid density of YBCO can be controlled by light illumination
Ya got ta know when ta hold âem: Maori women and gambling
Gambling among Maori women is under-researched. In this study, I interviewed thirty Maori
women to investigate how they got involved in gambling, what maintained their gambling and
what they thought might help to moderate their gambling. I found that the whanau was central
to understanding these issues. As children, my participants were exposed to gambling within
their whanau. As adults, whanau and other social support relationships were an integral part of
their gambling, which most commonly occurred in the context of card schools and housie. A
sense of reciprocity was important in both forms of gambling. Card schools were reported to be
close-knit groups within which the money circulated, giving all a chance to win. By playing
housie, the women felt that they were contributing to the welfare of their marae. Through the
social bonds of gambling and the acquisition of skills, gambling contributed to these womenâs
sense of identity. On the other hand, financial and relationship difficulties were identified as
negative consequences of gambling. The women felt there was a need for Maori-focused
services for problem gambling
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