684 research outputs found
High Dimensional Model Selection and Validation: A Comparison Study
Model selection is a challenging issue in high dimensional statistical analysis, and many approaches have been proposed in recent years. In this thesis, we compare the performance of three penalized logistic regression approaches (Ridge, Lasso, and Elastic Net) and three information criteria (AIC, BIC, and EBIC) on binary response variable in high dimensional situation through extensive simulation study. The models are built and selected on the training datasets, and their performance are evaluated through AUC on the validation datasets. We also display the comparison results on two real datasets (Arcene Data and University Retention Data). The performance differences among those approaches are discussed at the end
The Nelson-Seiberg theorem generalized with nonpolynomial superpotentials
The Nelson-Seiberg theorem relates R-symmetries to F-term supersymmetry
breaking, and provides a guiding rule for new physics model building beyond the
Standard Model. A revision of the theorem gives a necessary and sufficient
condition to supersymmetry breaking in models with polynomial superpotentials.
This work revisits the theorem to include models with nonpolynomial
superpotentials. With a generic R-symmetric superpotential, a singularity at
the origin of the field space implies both R-symmetry breaking and
supersymmetry breaking. We give a generalized necessary and sufficient
condition for supersymmetry breaking which applies to both perturbative and
nonperturbative models.Comment: 10 pages, discussions on D-terms, runaway models and existence of
vacua added, Advances in High Energy Physics accepted versio
Crystal structure of azilsartan methyl ester ethyl acetate hemisolvate
We gratefully acknowledge financial support from the NSFC (No. 21002009), the Scientific and Technological Project of Jiangsu Province (BY2014037ā01), the Major Program for Natural Science Research of Jiangsu Colleges and Universities (12ā
Kā
J A150002, 14ā
Kā
J A150002) and the Qing Lan Project of Jiangsu Province.Peer reviewe
The substructure and halo population of the Double Cluster and Persei
In order to study the stellar population and possible substructures in the
outskirts of Double Cluster and Persei, we investigate using the
GAIA DR2 data a sky area of about 7.5 degrees in radius around the Double
Cluster cores. We identify member stars using various criteria, including their
kinematics (viz, proper motion), individual parallaxes, as well as photometric
properties. A total of 2186 member stars in the parameter space were identified
as members. Based on the spatial distribution of the member stars, we find an
extended halo structure of and Persei, about 6 - 8 times larger than
their core radii. We report the discovery of filamentary substructures
extending to about 200 pc away from the Double Cluster. The tangential
velocities of these distant substructures suggest that they are more likely to
be the remnants of primordial structures, instead of a tidally disrupted stream
from the cluster cores. Moreover, the internal kinematic analysis indicates
that halo stars seems to be experiencing a dynamic stretching in the RA
direction, while the impact of the core components is relatively negligible.
This work also suggests that the physical scale and internal motions of young
massive star clusters may be more complex than previously thought.Comment: 9 pagges, 9 figures, Accecpted to A&
Improving PTM Site Prediction by Coupling of Multi-Granularity Structure and Multi-Scale Sequence Representation
Protein post-translational modification (PTM) site prediction is a
fundamental task in bioinformatics. Several computational methods have been
developed to predict PTM sites. However, existing methods ignore the structure
information and merely utilize protein sequences. Furthermore, designing a more
fine-grained structure representation learning method is urgently needed as PTM
is a biological event that occurs at the atom granularity. In this paper, we
propose a PTM site prediction method by Coupling of Multi-Granularity structure
and Multi-Scale sequence representation, PTM-CMGMS for brevity. Specifically,
multigranularity structure-aware representation learning is designed to learn
neighborhood structure representations at the amino acid, atom, and whole
protein granularity from AlphaFold predicted structures, followed by utilizing
contrastive learning to optimize the structure representations.Additionally,
multi-scale sequence representation learning is used to extract context
sequence information, and motif generated by aligning all context sequences of
PTM sites assists the prediction. Extensive experiments on three datasets show
that PTM-CMGMS outperforms the state-of-the-art methods
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