2,561 research outputs found
Multi-Label Learning with Label Enhancement
The task of multi-label learning is to predict a set of relevant labels for
the unseen instance. Traditional multi-label learning algorithms treat each
class label as a logical indicator of whether the corresponding label is
relevant or irrelevant to the instance, i.e., +1 represents relevant to the
instance and -1 represents irrelevant to the instance. Such label represented
by -1 or +1 is called logical label. Logical label cannot reflect different
label importance. However, for real-world multi-label learning problems, the
importance of each possible label is generally different. For the real
applications, it is difficult to obtain the label importance information
directly. Thus we need a method to reconstruct the essential label importance
from the logical multilabel data. To solve this problem, we assume that each
multi-label instance is described by a vector of latent real-valued labels,
which can reflect the importance of the corresponding labels. Such label is
called numerical label. The process of reconstructing the numerical labels from
the logical multi-label data via utilizing the logical label information and
the topological structure in the feature space is called Label Enhancement. In
this paper, we propose a novel multi-label learning framework called LEMLL,
i.e., Label Enhanced Multi-Label Learning, which incorporates regression of the
numerical labels and label enhancement into a unified framework. Extensive
comparative studies validate that the performance of multi-label learning can
be improved significantly with label enhancement and LEMLL can effectively
reconstruct latent label importance information from logical multi-label data.Comment: ICDM 201
Dark radiation from a unified dark fluid model
We present a unified dark fluid model to describe the possible evolutionary
behavior of in dark radiation. This model can be viewed
as an interacting model for the dark sectors, in which dark matter interacts
with dark radiation. We show that the evolution of can
be nicely explained without some drawbacks, such as the blowup of and the non-vanishing interaction at the late time.Comment: 12 pages, 4 figures, revised version accepted by PTE
Quantifying the impact of future Sandage-Loeb test data on dark energy constraints
The Sandage-Loeb (SL) test is a unique method to probe dark energy in the
"redshift desert" of , and thus it provides an important
supplement to the other dark energy probes. Therefore, it is of great
importance to quantify how the future SL test data impact on the dark energy
constraints. To avoid the potential inconsistency in data, we use the
best-fitting model based on the other geometric measurements as the fiducial
model to produce 30 mock SL test data. The 10-yr, 20-yr, and 30-yr observations
of SL test are analyzed and compared in detail. We show that compared to the
current combined data of type Ia supernovae, baryon acoustic oscillation,
cosmic microwave background, and Hubble constant, the 30-yr observation of SL
test could improve the constraint on by about and the
constraint on by about . Furthermore, the SL test can also improve the
measurement of the possible direct interaction between dark energy and dark
matter. We show that the SL test 30-yr data could improve the constraint on
by about and for the and models, respectively.Comment: 10 pages, 3 figure
Parameter estimation with Sandage-Loeb test
The Sandage-Loeb (SL) test directly measures the expansion rate of the
universe in the redshift range of by detecting redshift
drift in the spectra of Lyman- forest of distant quasars. We discuss
the impact of the future SL test data on parameter estimation for the
CDM, the CDM, and the CDM models. To avoid the potential
inconsistency with other observational data, we take the best-fitting dark
energy model constrained by the current observations as the fiducial model to
produce 30 mock SL test data. The SL test data provide an important supplement
to the other dark energy probes, since they are extremely helpful in breaking
the existing parameter degeneracies. We show that the strong degeneracy between
and in all the three dark energy models is well broken by the
SL test. Compared to the current combined data of type Ia supernovae, baryon
acoustic oscillation, cosmic microwave background, and Hubble constant, the
30-yr observation of SL test could improve the constraints on and
by more than 60\% for all the three models. But the SL test can only
moderately improve the constraint on the equation of state of dark energy. We
show that a 30-yr observation of SL test could help improve the constraint on
constant by about 25\%, and improve the constraints on and by
about 20\% and 15\%, respectively. We also quantify the constraining power of
the SL test in the future high-precision joint geometric constraints on dark
energy. The mock future supernova and baryon acoustic oscillation data are
simulated based on the space-based project JDEM. We find that the 30-yr
observation of SL test would help improve the measurement precision of
, , and by more than 70\%, 20\%, and 60\%, respectively,
for the CDM model.Comment: 16 pages, 9 figures, 3 tables; adding a new section to address future
SN and BAO observations; accepted for publication in JCA
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