3,598 research outputs found
Theoretic Analysis and Extremely Easy Algorithms for Domain Adaptive Feature Learning
Domain adaptation problems arise in a variety of applications, where a
training dataset from the \textit{source} domain and a test dataset from the
\textit{target} domain typically follow different distributions. The primary
difficulty in designing effective learning models to solve such problems lies
in how to bridge the gap between the source and target distributions. In this
paper, we provide comprehensive analysis of feature learning algorithms used in
conjunction with linear classifiers for domain adaptation. Our analysis shows
that in order to achieve good adaptation performance, the second moments of the
source domain distribution and target domain distribution should be similar.
Based on our new analysis, a novel extremely easy feature learning algorithm
for domain adaptation is proposed. Furthermore, our algorithm is extended by
leveraging multiple layers, leading to a deep linear model. We evaluate the
effectiveness of the proposed algorithms in terms of domain adaptation tasks on
the Amazon review dataset and the spam dataset from the ECML/PKDD 2006
discovery challenge.Comment: ijca
Detection of 40-48 GHz dust continuum linear polarization towards the Class 0 young stellar object IRAS 16293-2422
We performed the new JVLA full polarization observations at 40-48 GHz
(6.3-7.5 mm) towards the nearby ( 1473.4 pc) Class 0 YSO IRAS
16293-2422, and compare with the previous SMA observations reported by Rao et
al. (2009; 2014). We observed the quasar J1407+2827 which is weakly polarized
and can be used as a leakage term calibrator for 9 GHz observations, to
gauge the potential residual polarization leakage after calibration. We did not
detect Stokes Q, U, and V intensities from the observations of J1407+2827, and
constrain (3-) the residual polarization leakage after calibration to
be 0.3\%. We detect linear polarization from one of the two binary
components of our target source, IRAS\,16293-2422\,B. The derived polarization
position angles from our observations are in excellent agreement with those
detected from the previous observations of the SMA, implying that on the
spatial scale we are probing (50-1000 au), the physical mechanisms for
polarizing the continuum emission do not vary significantly over the wavelength
range of 0.88-7.5 mm. We hypothesize that the observed polarization
position angles trace the magnetic field which converges from large scale to an
approximately face-on rotating accretion flow. In this scenario, magnetic field
is predominantly poloidal on 100 au scales, and becomes toroidal on smaller
scales. However, this interpretation remains uncertain due to the high dust
optical depths at the central region of IRAS\,16293-2422\,B and the uncertain
temperature profile. We suggest that dust polarization at wavelengths
comparable or longer than 7\,mm may still trace interstellar magnetic field.
Future sensitive observations of dust polarization in the fully optically thin
regime will have paramount importance for unambiguously resolving the magnetic
field configuration.Comment: 14 pages, 7 figures, accepted to A&A. Comments are welcom
Timestamps as Prompts for Geography-Aware Location Recommendation
Location recommendation plays a vital role in improving users' travel
experience. The timestamp of the POI to be predicted is of great significance,
since a user will go to different places at different times. However, most
existing methods either do not use this kind of temporal information, or just
implicitly fuse it with other contextual information. In this paper, we revisit
the problem of location recommendation and point out that explicitly modeling
temporal information is a great help when the model needs to predict not only
the next location but also further locations. In addition, state-of-the-art
methods do not make effective use of geographic information and suffer from the
hard boundary problem when encoding geographic information by gridding. To this
end, a Temporal Prompt-based and Geography-aware (TPG) framework is proposed.
The temporal prompt is firstly designed to incorporate temporal information of
any further check-in. A shifted window mechanism is then devised to augment
geographic data for addressing the hard boundary problem. Via extensive
comparisons with existing methods and ablation studies on five real-world
datasets, we demonstrate the effectiveness and superiority of the proposed
method under various settings. Most importantly, our proposed model has the
superior ability of interval prediction. In particular, the model can predict
the location that a user wants to go to at a certain time while the most recent
check-in behavioral data is masked, or it can predict specific future check-in
(not just the next one) at a given timestamp
Effect of diabetes on mortality and length of hospital stay in patients with renal or perinephric abscess
OBJECTIVES: We compared the risk of in-hospital mortality and the length of hospital stay between diabetic and non-diabetic patients hospitalized for renal or perinephric abscess. METHOD: The data analyzed in this study were retrieved from Taiwan's National Health Insurance claims. The risk of in-hospital mortality and the length of hospital stay were compared between 1,715 diabetic patients, hospitalized because of renal or perinephric abscess in Taiwan between 1997 and 2007, and a random sample of 477 non-diabetes patients with renal or perinephric abscess. RESULTS: The in-hospital mortality rates from renal or perinephric abscess for the diabetic patients and the non-diabetic patients were not different, at 2.3% and 3.4%, respectively. However, diabetes was significantly associated with a longer length of hospital stay among patients with renal abscess, by 3.38 days (95% confidence interval [CI]: 1.59-5.17). CONCLUSIONS: Diabetes does not increase the risk of in-hospital mortality from renal or perinephric abscess. Nevertheless, appropriate management of patients with diabetes and concurrent renal or perinephric abscess is essential to reduce the length of hospital stay
Controlling magnetization reversal in Co/Pt nanostructures with perpendicular anisotropy
We demonstrate a simple method to tailor the magnetization reversal
mechanisms of Co/Pt multilayers by depositing them onto large area nanoporous
anodized alumina (AAO) with various aspect ratios, A = pore depth/diameter.
Magnetization reversal of composite (Co/Pt)/AAO films with large A is governed
by strong domain-wall pinning which gradually transforms into a
rotation-dominated reversal for samples with smaller A, as investigated by a
first-order reversal curve method in conjunction with analysis of the angular
dependent switching fields. The change of the magnetization reversal mode is
attributed to topographical changes induced by the aspect ratio of the AAO
templates.Comment: 12 pages, 3 figure
Ample Pairs
We show that the ample degree of a stable theory with trivial forking is
preserved when we consider the corresponding theory of belles paires, if it
exists. This result also applies to the theory of -structures of a trivial
theory of rank .Comment: Research partially supported by the program MTM2014-59178-P. The
second author conducted research with support of the programme
ANR-13-BS01-0006 Valcomo. The third author would like to thank the European
Research Council grant 33882
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