366 research outputs found
The Study of Reciprocal Impact between Dehua and European Porcelain: An Analysis of the Influence on Porcelain Making Skills, Shapes, and Decoration Styles
The present study investigates the reciprocal impact between the Dehua porcelain and European porcelain, and possible aesthetics in monochrome by exploring the history and significance of Dehua porcelain in relation to its connection with European porcelain. The article discusses the origins and evolution of Dehua porcelain, including its characteristics, kilns, and exportation to other parts of the world, particularly Europe. It also analyzes the influence of Dehua porcelain on the creation and development of European porcelain, from the Rouen, to Meissen, S.Cloud, and Chelsea company and Sèvres company porcelain. The article alsoexamines the impact of European merchants on the westernization of Dehua porcelain, as well as the existence of universal aesthetics in monochrome. However, the study acknowledges possible limitations due to the lack of literature and access to data, which could affect the conclusions of the research
Formation, Orbital and Internal Evolutions of Young Planetary Systems
The growing body of observational data on extrasolar planets and
protoplanetary disks has stimulated intense research on planet formation and
evolution in the past few years. The extremely diverse, sometimes unexpected
physical and orbital characteristics of exoplanets lead to frequent updates on
the mainstream scenarios for planet formation and evolution, but also to the
exploration of alternative avenues. The aim of this review is to bring together
classical pictures and new ideas on the formation, orbital and internal
evolutions of planets, highlighting the key role of the protoplanetary disk in
the various parts of the theory. We begin by briefly reviewing the conventional
mechanism of core accretion by the growth of planetesimals, and discuss a
relatively recent model of core growth through the accretion of pebbles. We
review the basic physics of planet-disk interactions, recent progress in this
area, and discuss their role in observed planetary systems. We address the most
important effects of planets internal evolution, like cooling and contraction,
the mass-luminosity relation, and the bulk composition expressed in the
mass-radius and mass-mean density relations.Comment: 49 pages, 12 figures, accepted for publication in Space Science
Reviews. Chapter in International Space Science Institute (ISSI) Book on "The
Disk in Relation to the Formation of Planets and their Proto-atmospheres" to
be published in Space Science Reviews by Springe
Three-dimensional Global Simulations of Type-II Planet-disk Interaction with a Magnetized Disk Wind: I. Magnetic Flux Concentration and Gap Properties
Giant planets embedded in protoplanetary disks (PPDs) can create annulus
density gaps around their orbits in the type-II regime, potentially responsible
for the ubiquity of annular substructures observed in PPDs. Despite of
substantial amount of works studying type-II planet migration and gap
properties, they are almost exclusively conducted under the viscous accretion
disk framework. However, recent studies have established magnetized disk winds
as the primary driving disk accretion and evolution, which can co-exist with
turbulence from the magneto-rotational instability (MRI) in the outer PPDs. We
conduct a series of 3D global non-ideal magneto-hydrodynamic (MHD) simulations
of type-II planet-disk interaction applicable to the outer PPDs. Our
simulations properly resolve the MRI turbulence and accommodate the MHD disk
wind. We found that the planet triggers the poloidal magnetic flux
concentration around its orbit. The concentrated magnetic flux strongly
enhances angular momentum removal in the gap, which is along the inclined
poloidal field through a strong outflow emanating from the disk surface outward
of the planet gap. The resulting planet-induced gap shape is more similar to an
inviscid disk, while being much deeper, which can be understood from a simple
inhomogeneous wind torque prescription. The corotation region is characterized
by a fast trans-sonic accretion flow that is asymmetric in azimuth about the
planet and lacking the horseshoe turns, and the meridional flow is weakened.
The torque acting on the planet generally drives inward migration, though the
migration rate can be affected by the presence of neighboring gaps through
stochastic, planet-free magnetic flux concentration.Comment: 42 pages, 24 figures, Accepted for publication in the Astrophysical
Journa
STUDY ON OPTIMAL COMBINATION SETTLEMENT PREDICTION MODEL BASED ON LOGISTIC CURVE AND GOMPERTZ CURVE
The Logistic and Gompertz embankment settlement prediction models have poor prediction accuracy for the late settlement of high-filled soil. This study proposes a combination of the two models based on their common characteristics and individuality, and their respective advantages and specific limitations. The minimum logarithmic error square sum of the combined model was used as the objective function to solve the optimal weighting coefficient. The optimal weighted geometric mean combination prediction model was deduced, to improve the confidence of the prediction accuracy of the settlement of high-filled soil. By fitting and analysing the measured settlement data of the engineered high-filled soil with each prediction model, the feasibility of the proposed optimal combination prediction model in the settlement prediction of high-filled soil was tested. It was found that the proposed optimal combination forecasting model was more accurate and adaptable compared to any single model, and was more reliable. Therefore, the proposed combination forecasting model could be used as an effective method to predict the settlement of high-filled soil in the later stages of settlement
Distributed Logistic Regression for Massive Data with Rare Events
Large-scale rare events data are commonly encountered in practice. To tackle
the massive rare events data, we propose a novel distributed estimation method
for logistic regression in a distributed system. For a distributed framework,
we face the following two challenges. The first challenge is how to distribute
the data. In this regard, two different distribution strategies (i.e., the
RANDOM strategy and the COPY strategy) are investigated. The second challenge
is how to select an appropriate type of objective function so that the best
asymptotic efficiency can be achieved. Then, the under-sampled (US) and inverse
probability weighted (IPW) types of objective functions are considered. Our
results suggest that the COPY strategy together with the IPW objective function
is the best solution for distributed logistic regression with rare events. The
finite sample performance of the distributed methods is demonstrated by
simulation studies and a real-world Sweden Traffic Sign dataset
Subsampling and Jackknifing: A Practically Convenient Solution for Large Data Analysis with Limited Computational Resources
Modern statistical analysis often encounters datasets with large sizes. For
these datasets, conventional estimation methods can hardly be used immediately
because practitioners often suffer from limited computational resources. In
most cases, they do not have powerful computational resources (e.g., Hadoop or
Spark). How to practically analyze large datasets with limited computational
resources then becomes a problem of great importance. To solve this problem, we
propose here a novel subsampling-based method with jackknifing. The key idea is
to treat the whole sample data as if they were the population. Then, multiple
subsamples with greatly reduced sizes are obtained by the method of simple
random sampling with replacement. It is remarkable that we do not recommend
sampling methods without replacement because this would incur a significant
cost for data processing on the hard drive. Such cost does not exist if the
data are processed in memory. Because subsampled data have relatively small
sizes, they can be comfortably read into computer memory as a whole and then
processed easily. Based on subsampled datasets, jackknife-debiased estimators
can be obtained for the target parameter. The resulting estimators are
statistically consistent, with an extremely small bias. Finally, the
jackknife-debiased estimators from different subsamples are averaged together
to form the final estimator. We theoretically show that the final estimator is
consistent and asymptotically normal. Its asymptotic statistical efficiency can
be as good as that of the whole sample estimator under very mild conditions.
The proposed method is simple enough to be easily implemented on most practical
computer systems and thus should have very wide applicability
CoGANPPIS: Coevolution-enhanced Global Attention Neural Network for Protein-Protein Interaction Site Prediction
Protein-protein interactions are essential in biochemical processes. Accurate
prediction of the protein-protein interaction sites (PPIs) deepens our
understanding of biological mechanism and is crucial for new drug design.
However, conventional experimental methods for PPIs prediction are costly and
time-consuming so that many computational approaches, especially ML-based
methods, have been developed recently. Although these approaches have achieved
gratifying results, there are still two limitations: (1) Most models have
excavated some useful input features, but failed to take coevolutionary
features into account, which could provide clues for inter-residue
relationships; (2) The attention-based models only allocate attention weights
for neighboring residues, instead of doing it globally, neglecting that some
residues being far away from the target residues might also matter.
We propose a coevolution-enhanced global attention neural network, a
sequence-based deep learning model for PPIs prediction, called CoGANPPIS. It
utilizes three layers in parallel for feature extraction: (1) Local-level
representation aggregation layer, which aggregates the neighboring residues'
features; (2) Global-level representation learning layer, which employs a novel
coevolution-enhanced global attention mechanism to allocate attention weights
to all the residues on the same protein sequences; (3) Coevolutionary
information learning layer, which applies CNN & pooling to coevolutionary
information to obtain the coevolutionary profile representation. Then, the
three outputs are concatenated and passed into several fully connected layers
for the final prediction. Application on two benchmark datasets demonstrated a
state-of-the-art performance of our model. The source code is publicly
available at https://github.com/Slam1423/CoGANPPIS_source_code
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