266 research outputs found
The Smallest Bipartite Intrinsically Knotted Graph
We use the restoring method of Kim, Mattman, and Oh to prove that the Heawood graph is the only bipartite graph with 21 edges that is intrinsically knotted
Development of a Causal Model for Improving Rural Seniors' Accessibility: Data Evidences
Seniors residing in rural areas often encounter limited accessibility to
opportunities, resources, and services. This paper introduces a model proposing
that both aging and rural residency are factors contributing to the restricted
accessibility faced by rural seniors. Leveraging data from the 2017 National
Household Travel Survey, the study examines three hypotheses pertaining to this
causal model. Multiple causal pathways emerge in the data analysis, with
mobility identified as a mediator in one of them. The study further identifies
specific challenges faced by rural seniors, such as the reduced accessibility
in reaching medical services and assisting others. These challenges stem
primarily from aging and geographic obstacles that not only diminish their
willingness to travel but also restrict more in the group from choosing
transportation modes with higher mobility. The insights gained from this study
serve as a foundation for devising effective methods to enhance transportation
accessibility for seniors in rural areas.Comment: 12 pages 5 table
OpenCAEPoro: A Parallel Simulation Framework for Multiphase and Multicomponent Porous Media Flows
OpenCAEPoro is a parallel numerical simulation software developed in C++ for
simulating multiphase and multicomponent flows in porous media. The software
utilizes a set of general-purpose compositional model equations, enabling it to
handle a diverse range of fluid dynamics, including the black oil model,
compositional model, and thermal recovery models. OpenCAEPoro establishes a
unified solving framework that integrates many widely used methods, such as
IMPEC, FIM, and AIM. This framework allows dynamic collaboration between
different methods. Specifically, based on this framework, we have developed an
adaptively coupled domain decomposition method, which can provide initial
solutions for global methods to accelerate the simulation. The reliability of
OpenCAEPoro has been validated through benchmark testing with the SPE
comparative solution project. Furthermore, its robust parallel efficiency has
been tested in distributed parallel environments, demonstrating its suitability
for large-scale simulation problems.Comment: 29 pages, 19 figure
Test for high-dimensional mean vectors via the weighted -norm
In this paper, we propose a novel approach to test the equality of
high-dimensional mean vectors of several populations via the weighted
-norm. We establish the asymptotic normality of the test statistics under
the null hypothesis. We also explain theoretically why our test statistics can
be highly useful in weakly dense cases when the nonzero signal in mean vectors
is present. Furthermore, we compare the proposed test with existing tests using
simulation results, demonstrating that the weighted -norm-based test
statistic exhibits favorable properties in terms of both size and power
Test for high-dimensional linear hypothesis of mean vectors via random integration
In this paper, we investigate hypothesis testing for the linear combination
of mean vectors across multiple populations through the method of random
integration. We have established the asymptotic distributions of the test
statistics under both null and alternative hypotheses. Additionally, we provide
a theoretical explanation for the special use of our test statistics in
situations when the nonzero signal in the linear combination of the true mean
vectors is weakly dense. Moreover, Monte-Carlo simulations are presented to
evaluate the suggested test against existing high-dimensional tests. The
findings from these simulations reveal that our test not only aligns with the
performance of other tests in terms of size but also exhibits superior power
Complex-valued K-means clustering of interpolative separable density fitting algorithm for large-scale hybrid functional enabled \textit{ab initio} molecular dynamics simulations within plane waves
K-means clustering, as a classic unsupervised machine learning algorithm, is
the key step to select the interpolation sampling points in interpolative
separable density fitting (ISDF) decomposition. Real-valued K-means clustering
for accelerating the ISDF decomposition has been demonstrated for large-scale
hybrid functional enabled \textit{ab initio} molecular dynamics (hybrid AIMD)
simulations within plane-wave basis sets where the Kohn-Sham orbitals are
real-valued. However, it is unclear whether such K-means clustering works for
complex-valued Kohn-Sham orbitals. Here, we apply the K-means clustering into
hybrid AIMD simulations for complex-valued Kohn-Sham orbitals and use an
improved weight function defined as the sum of the square modulus of
complex-valued Kohn-Sham orbitals in K-means clustering. Numerical results
demonstrate that this improved weight function in K-means clustering algorithm
yields smoother and more delocalized interpolation sampling points, resulting
in smoother energy potential, smaller energy drift and longer time steps for
hybrid AIMD simulations compared to the previous weight function used in the
real-valued K-means algorithm. In particular, we find that this improved
algorithm can obtain more accurate oxygen-oxygen radial distribution functions
in liquid water molecules and more accurate power spectrum in crystal silicon
dioxide compared to the previous K-means algorithm. Finally, we describe a
massively parallel implementation of this ISDF decomposition to accelerate
large-scale complex-valued hybrid AIMD simulations containing thousands of
atoms (2,744 atoms), which can scale up to 5,504 CPU cores on modern
supercomputers.Comment: 43 pages, 12 figure
Quantification of Genome Editing and Transcriptional Control Capabilities Reveals Hierarchies among Diverse CRISPR/Cas Systems in Human Cells
CRISPR/Cas technologies have revolutionized the ability to redesign genomic information and tailor endogenous gene expression. Nevertheless, the discovery and development of new CRISPR/Cas systems has resulted in a lack of clarity surrounding the relative efficacies among these technologies in human cells. This deficit makes the optimal selection of CRISPR/Cas technologies in human cells unnecessarily challenging, which in turn hampers their adoption, and thus ultimately limits their utility. Here, we designed a series of endogenous testbed systems to methodically quantify and compare the genome editing, CRISPRi, and CRISPRa capabilities among 10 different natural and engineered Cas protein variants spanning Type II and Type V CRISPR/Cas families. We show that although all Cas protein variants are capable of genome editing and transcriptional control in human cells, hierarchies exist, particularly for genome editing and CRISPRa applications, wherein Cas9 ≥ Cas12a > Cas12e/Cas12j. Our findings also highlight the utility of our modular testbed platforms to rapidly and systematically quantify the functionality of practically any natural or engineered genomic-targeting Cas protein in human cells
UniTime: A Language-Empowered Unified Model for Cross-Domain Time Series Forecasting
Multivariate time series forecasting plays a pivotal role in contemporary web
technologies. In contrast to conventional methods that involve creating
dedicated models for specific time series application domains, this research
advocates for a unified model paradigm that transcends domain boundaries.
However, learning an effective cross-domain model presents the following
challenges. First, various domains exhibit disparities in data characteristics,
e.g., the number of variables, posing hurdles for existing models that impose
inflexible constraints on these factors. Second, the model may encounter
difficulties in distinguishing data from various domains, leading to suboptimal
performance in our assessments. Third, the diverse convergence rates of time
series domains can also result in compromised empirical performance. To address
these issues, we propose UniTime for effective cross-domain time series
learning. Concretely, UniTime can flexibly adapt to data with varying
characteristics. It also uses domain instructions and a Language-TS Transformer
to offer identification information and align two modalities. In addition,
UniTime employs masking to alleviate domain convergence speed imbalance issues.
Our extensive experiments demonstrate the effectiveness of UniTime in advancing
state-of-the-art forecasting performance and zero-shot transferability
TeViS:Translating Text Synopses to Video Storyboards
A video storyboard is a roadmap for video creation which consists of
shot-by-shot images to visualize key plots in a text synopsis. Creating video
storyboards, however, remains challenging which not only requires cross-modal
association between high-level texts and images but also demands long-term
reasoning to make transitions smooth across shots. In this paper, we propose a
new task called Text synopsis to Video Storyboard (TeViS) which aims to
retrieve an ordered sequence of images as the video storyboard to visualize the
text synopsis. We construct a MovieNet-TeViS dataset based on the public
MovieNet dataset. It contains 10K text synopses each paired with keyframes
manually selected from corresponding movies by considering both relevance and
cinematic coherence. To benchmark the task, we present strong CLIP-based
baselines and a novel VQ-Trans. VQ-Trans first encodes text synopsis and images
into a joint embedding space and uses vector quantization (VQ) to improve the
visual representation. Then, it auto-regressively generates a sequence of
visual features for retrieval and ordering. Experimental results demonstrate
that VQ-Trans significantly outperforms prior methods and the CLIP-based
baselines. Nevertheless, there is still a large gap compared to human
performance suggesting room for promising future work. The code and data are
available at: \url{https://ruc-aimind.github.io/projects/TeViS/}Comment: Accepted to ACM Multimedia 202
Acupuncture Treatment for Post-Stroke Depression: Intestinal Microbiota and Its Role
Stroke-induced depression is a common complication and an important risk factor for disability. Besides psychiatric symptoms, depressed patients may also exhibit a variety of gastrointestinal symptoms, and even take gastrointestinal symptoms as the primary reason for medical treatment. It is well documented that stress may disrupt the balance of the gut microbiome in patients suffering from post-stroke depression (PSD), and that disruption of the gut microbiome is closely related to the severity of the condition in depressed patients. Therefore, maintaining the balance of intestinal microbiota can be the focus of research on the mechanism of acupuncture in the treatment of PSD. Furthermore, stroke can be effectively treated with acupuncture at all stages and it may act as a special microecological regulator by regulating intestinal microbiota as well. In this article, we reviewed the studies on changing intestinal microbiota after acupuncture treatment and examined the existing problems and development prospects of acupuncture, microbiome, and poststroke depression, in order to provide new ideas for future acupuncture research
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