4,388 research outputs found
A Sparse Graph-Structured Lasso Mixed Model for Genetic Association with Confounding Correction
While linear mixed model (LMM) has shown a competitive performance in
correcting spurious associations raised by population stratification, family
structures, and cryptic relatedness, more challenges are still to be addressed
regarding the complex structure of genotypic and phenotypic data. For example,
geneticists have discovered that some clusters of phenotypes are more
co-expressed than others. Hence, a joint analysis that can utilize such
relatedness information in a heterogeneous data set is crucial for genetic
modeling.
We proposed the sparse graph-structured linear mixed model (sGLMM) that can
incorporate the relatedness information from traits in a dataset with
confounding correction. Our method is capable of uncovering the genetic
associations of a large number of phenotypes together while considering the
relatedness of these phenotypes. Through extensive simulation experiments, we
show that the proposed model outperforms other existing approaches and can
model correlation from both population structure and shared signals. Further,
we validate the effectiveness of sGLMM in the real-world genomic dataset on two
different species from plants and humans. In Arabidopsis thaliana data, sGLMM
behaves better than all other baseline models for 63.4% traits. We also discuss
the potential causal genetic variation of Human Alzheimer's disease discovered
by our model and justify some of the most important genetic loci.Comment: Code available at https://github.com/YeWenting/sGLM
Interference and switching effect of topological interfacial modes with geometric phase
We investigate interference between topological interfacial modes in a
semiconductor photonic crystal platform with Dirac frequency dispersions, which
can be exploited for interferometry switch. It is showcased that, in a
two-in/two-out structure with four topological waveguides, geometric phases of
the two-component spinor wavefunctions of topological photonic modes accumulate
at turning points of waveguides, which govern the interferences and split the
electromagnetic energy into two output ports with relative power ratio tunable
by the relative phase of inputs. We unveil that this brand-new photonic
phenomenon is intimately related to the spin-momentum locking property of
quantum spin Hall effect, and results from the symphonic contributions of three
phase variables: the spinor phase and geometric phase upon design, and the
global phase controlled from outside. The present findings open the door for
manipulating topological interfacial modes, thus exposing a new facet of
topological physics. The topology-driven interference can be incorporated into
other devices which is expected to leave far-reaching impacts to advanced
photonics, optomechanics and phononics applications.Comment: 25 pages, 4 figure
L
This paper is concerned with the problem of controller design for switched systems under asynchronous switching with exogenous disturbances. The attention is focused on designing the feedback controller that guarantees the finite-time bounded and L∞ finite-time stability of the dynamic system. Firstly, when there exists asynchronous switching between the controller and the system, a sufficient condition for the existence of stabilizing switching law for the addressed switched system is derived. It is proved that the switched system is finite-time stabilizable under asynchronous switching satisfying the average dwell-time condition. Furthermore, the problem of L∞ control for switched systems under asynchronous switching is also investigated. Finally, a numerical example is given to illustrate the effectiveness of the proposed method
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