478 research outputs found
TempEE: Temporal-Spatial Parallel Transformer for Radar Echo Extrapolation Beyond Auto-Regression
Meteorological radar reflectivity data (i.e. radar echo) significantly
influences precipitation prediction. It can facilitate accurate and expeditious
forecasting of short-term heavy rainfall bypassing the need for complex
Numerical Weather Prediction (NWP) models. In comparison to conventional
models, Deep Learning (DL)-based radar echo extrapolation algorithms exhibit
higher effectiveness and efficiency. Nevertheless, the development of reliable
and generalized echo extrapolation algorithm is impeded by three primary
challenges: cumulative error spreading, imprecise representation of sparsely
distributed echoes, and inaccurate description of non-stationary motion
processes. To tackle these challenges, this paper proposes a novel radar echo
extrapolation algorithm called Temporal-Spatial Parallel Transformer, referred
to as TempEE. TempEE avoids using auto-regression and instead employs a
one-step forward strategy to prevent cumulative error spreading during the
extrapolation process. Additionally, we propose the incorporation of a
Multi-level Temporal-Spatial Attention mechanism to improve the algorithm's
capability of capturing both global and local information while emphasizing
task-related regions, including sparse echo representations, in an efficient
manner. Furthermore, the algorithm extracts spatio-temporal representations
from continuous echo images using a parallel encoder to model the
non-stationary motion process for echo extrapolation. The superiority of our
TempEE has been demonstrated in the context of the classic radar echo
extrapolation task, utilizing a real-world dataset. Extensive experiments have
further validated the efficacy and indispensability of various components
within TempEE.Comment: Have been accepted by IEEE Transactions on Geoscience and Remote
Sensing, see https://ieeexplore.ieee.org/document/1023874
MASK-CNN-Transformer For Real-Time Multi-Label Weather Recognition
Weather recognition is an essential support for many practical life
applications, including traffic safety, environment, and meteorology. However,
many existing related works cannot comprehensively describe weather conditions
due to their complex co-occurrence dependencies. This paper proposes a novel
multi-label weather recognition model considering these dependencies. The
proposed model called MASK-Convolutional Neural Network-Transformer (MASK-CT)
is based on the Transformer, the convolutional process, and the MASK mechanism.
The model employs multiple convolutional layers to extract features from
weather images and a Transformer encoder to calculate the probability of each
weather condition based on the extracted features. To improve the
generalization ability of MASK-CT, a MASK mechanism is used during the training
phase. The effect of the MASK mechanism is explored and discussed. The Mask
mechanism randomly withholds some information from one-pair training instances
(one image and its corresponding label). There are two types of MASK methods.
Specifically, MASK-I is designed and deployed on the image before feeding it
into the weather feature extractor and MASK-II is applied to the image label.
The Transformer encoder is then utilized on the randomly masked image features
and labels. The experimental results from various real-world weather
recognition datasets demonstrate that the proposed MASK-CT model outperforms
state-of-the-art methods. Furthermore, the high-speed dynamic real-time weather
recognition capability of the MASK-CT is evaluated.Comment: Under Revie
Open quantum dynamics of single-photon optomechanical devices
We study the quantum dynamics of a Michelson interferometer with Fabry-Perot
cavity arms and one movable end mirror, and driven by a single photon --- an
optomechanical device previously studied by Marshall et al. as a device that
searches for gravity decoherence. We obtain an exact analytical solution for
the system's quantum mechanical equations of motion, including details about
the exchange of the single photon between the cavity mode and the external
continuum. The resulting time evolution of the interferometer's fringe
visibility displays interesting new features when the incoming photon's
frequency uncertainty is narrower or comparable to the cavity's line width ---
only in the limiting case of much broader-band photon does the result return to
that of Marshall et al., but in this case the photon is not very likely to
enter the cavity and interact with the mirror, making the experiment less
efficient and more susceptible to imperfections. In addition, we show that in
the strong-coupling regime, by engineering the incoming photon's wave function,
it is possible to prepare the movable mirror into an arbitrary quantum state of
a multi-dimensional Hilbert space.Comment: 14 pages and 9 figures. Comments are welcom
Effect of Physical Exercise on Life Satisfaction of Chinese Primary Students: The Chain Mediating Role of Self-Confidence and Resilience
Life satisfaction is an overall cognitive evaluation of an individual\u27s living condition for the most of time or over a certain period of time according to the standard of one’s own choice. It is an important psychological variable in the developmental stage of children and adolescents. Some studies had shown that life satisfaction was closely related to children\u27s and adolescents\u27 mental health levels, including their emotional and behavioral conditions. However, the Blue Book for Children: China Children\u27s Development Report (2020) published by China Children\u27s Center stated that Chinese students did not fare well in terms of life satisfaction. Previous studies had indicated that physical exercise was an important factor that had a positive effect on life satisfaction, as well as on self-confidence and resilience. Also, there is a correlation between self-confidence, resilience, and life satisfaction. Nonetheless, few studies have researched the role of self-confidence and resilience in the impact of physical exercise on the life satisfaction of primary school students. To explore the mediating role of self-confidence and resilience between physical exercise and life satisfaction, in order to provide a theoretical basis and practical guidance for how to effectively promote life satisfaction and psychological well-being of primary school students in the practice of physical exercise. Group measurements of 1009 students (519 boys and 490 girls; 576 fifth graders and 433 sixth graders) are carried out by using the Scale of Physical Exercise Level, Children and Adolescent Self-Confidence Scale, Children and Adolescent Life Satisfaction Scale, and Adolescent Resilience Scale, and Structural Equation Model and Bootstrap are used to analyze the mediating effect of self-confidence and resilience. The results reveal that there is a positive correlation between physical exercise and life satisfaction (r=0.218), but the effect on life satisfaction is not significant (P=0.516); the indirect effect of physical exercise on life satisfaction consists of two paths: physical exercise to self-confidence to life satisfaction (95% CI: 0.128,0.267); physical exercise to self-confidence to resilience to life satisfaction (95% CI:0.109,0.209). It is concluded that physical exercise has an indirect but significant effect on primary school students\u27 life satisfaction--the independent mediating effect of self-confidence and the chain mediation effect of self-confidence and resilience. The study further confirms that physical exercise can promote students\u27 self-confidence levels and the formation of tenacious psychological quality, thus improving their life satisfaction levels. Therefore, society, schools and families should pay close attention to the positive effects of physical exercise on primary school students’ emotional and behavioral conditions
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Paxillin facilitates timely neurite initiation on soft-substrate environments by interacting with the endocytic machinery.
Neurite initiation is the first step in neuronal development and occurs spontaneously in soft tissue environments. Although the mechanisms regulating the morphology of migratory cells on rigid substrates in cell culture are widely known, how soft environments modulate neurite initiation remains elusive. Using hydrogel cultures, pharmacologic inhibition, and genetic approaches, we reveal that paxillin-linked endocytosis and adhesion are components of a bistable switch controlling neurite initiation in a substrate modulus-dependent manner. On soft substrates, most paxillin binds to endocytic factors and facilitates vesicle invagination, elevating neuritogenic Rac1 activity and expression of genes encoding the endocytic machinery. By contrast, on rigid substrates, cells develop extensive adhesions, increase RhoA activity and sequester paxillin from the endocytic machinery, thereby delaying neurite initiation. Our results highlight paxillin as a core molecule in substrate modulus-controlled morphogenesis and define a mechanism whereby neuronal cells respond to environments exhibiting varying mechanical properties
Brownian Thermal Noise in Multilayer Coated Mirrors
We analyze the Brownian thermal noise of a multi-layer dielectric coating,
used in high-precision optical measurements including interferometric
gravitational-wave detectors. We assume the coating material to be isotropic,
and therefore study thermal noises arising from shear and bulk losses of the
coating materials. We show that coating noise arises not only from layer
thickness fluctuations, but also from fluctuations of the interface between the
coating and substrate, driven by internal fluctuating stresses of the coating.
In addition, the non-zero photoeleastic coefficients of the thin films modifies
the influence of the thermal noise on the laser field. The thickness
fluctuations of different layers are statistically independent, however, there
exists a finite coherence between layers and the substrate-coating interface.
Taking into account uncertainties in material parameters, we show that
significant uncertainties still exist in estimating coating Brownian noise.Comment: 26 pages, 18 figure
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