682 research outputs found
How to Understand Chinese Foreign Policy and Role in Northeast Asia
No abstract available. DOI: http://dx.doi.org/10.5564/mjia.v0i10.118 The Mongolian Journal of International Affairs; Number 10, 2003, Pages 46-5
International Trade and Revenue-Based Total Factor Productivity: A Firm-Level Analysis
Economists concur that international trade is conducive to economic growth. However, at the firm level, variation exists. In this article, my goal is to conduct economic analysis on firm- level data and study the productivity effects of trade. With the comprehensive World Bank Enterprise Surveys data, I first explore trade patterns across different firms, controlling for industry, firm size, and the legal status of the firm. I then conduct regression analysis to identify characteristics of firms that participate in trade. Finally, I use an instrumental variable regression to study the causal relationship between a firm’s productivity and its participation in trade
Cofilin Activation in Peripheral CD4 T Cells of HIV-1 Infected Patients: A Pilot Study
Cofilin is an actin-depolymerizing factor that regulates actin dynamics critical for T cell migration and T cell activation. In unstimulated resting CD4 T cells, cofilin exists largely as a phosphorylated inactive form. Previously, we demonstrated that during HIV-1 infection of resting CD4 T cells, the viral envelope-CXCR4 signaling activates cofilin to overcome the static cortical actin restriction. In this pilot study, we have extended this in vitro observation and examined cofilin phosphorylation in resting CD4 T cells purified from the peripheral blood of HIV-1-infected patients. Here, we report that the resting T cells from infected patients carry significantly higher levels of active cofilin, suggesting that these resting cells have been primed in vivo in cofilin activity to facilitate HIV-1 infection. HIV-1-mediated aberrant activation of cofilin may also lead to abnormalities in T cell migration and activation that could contribute to viral pathogenesis.Department of Defense (National Defense Science and Engineering Fellowship); National Institute of Allergy and Infectious Diseases (AI069981
Demonstration of non-Abelian frame charge flow in photonic crystals
In PT symmetric systems, the notion of non-Abelian frame charges enables
multiband topological characterization of the degeneracy nodes through
examining the eigenvector frame rotations. Interestingly, some features of
these frame charges can be viewed as an analogue of electric charges confined
in conducting wires, only that they flow in momentum space along nodal lines.
However, these frame charges are not integers, and non-Abelian signatures
emerge when braiding between adjacent band nodal lines occurs, which flips the
direction of the flow. In photonic systems, we discover that the photonic
{\Gamma} point serves as the source or sink of such frame charge flow due to a
hidden braiding induced by the often-ignored electrostatic mode at
zero-frequency. We use biaxial photonic crystals as examples and show how
complex nodal line configurations can be explained as the topological
consequences of the frame charge flow from the {\Gamma} point to the Brillouin
zone boundaries. We further designed and fabricated meta-crystals to
experimentally observe these line nodes as manifestation of the non-Abelian
frame charge flow
OmniDataComposer: A Unified Data Structure for Multimodal Data Fusion and Infinite Data Generation
This paper presents OmniDataComposer, an innovative approach for multimodal
data fusion and unlimited data generation with an intent to refine and
uncomplicate interplay among diverse data modalities. Coming to the core
breakthrough, it introduces a cohesive data structure proficient in processing
and merging multimodal data inputs, which include video, audio, and text. Our
crafted algorithm leverages advancements across multiple operations such as
video/image caption extraction, dense caption extraction, Automatic Speech
Recognition (ASR), Optical Character Recognition (OCR), Recognize Anything
Model(RAM), and object tracking. OmniDataComposer is capable of identifying
over 6400 categories of objects, substantially broadening the spectrum of
visual information. It amalgamates these diverse modalities, promoting
reciprocal enhancement among modalities and facilitating cross-modal data
correction. \textbf{The final output metamorphoses each video input into an
elaborate sequential document}, virtually transmuting videos into thorough
narratives, making them easier to be processed by large language models. Future
prospects include optimizing datasets for each modality to encourage unlimited
data generation. This robust base will offer priceless insights to models like
ChatGPT, enabling them to create higher quality datasets for video captioning
and easing question-answering tasks based on video content. OmniDataComposer
inaugurates a new stage in multimodal learning, imparting enormous potential
for augmenting AI's understanding and generation of complex, real-world data
Estimation of non-symmetric and unbounded region of attraction using shifted shape function and R-composition
A general numerical method using sum of squares programming is proposed to
address the problem of estimating the region of attraction (ROA) of an
asymptotically stable equilibrium point of a nonlinear polynomial system. The
method is based on Lyapunov theory, and a shape function is defined to enlarge
the provable subset of a local Lyapunov function. In contrast with existing
methods with a shape function centered at the equilibrium point, the proposed
method utilizes a shifted shape function (SSF) with its center shifted
iteratively towards the boundary of the newly obtained invariant subset to
improve ROA estimation. A set of shifting centers with corresponding SSFs is
generated to produce proven subsets of the exact ROA and then a composition
method, namely R-composition, is employed to express these independent sets in
a compact form by just a single but richer-shaped level set. The proposed
method denoted as RcomSSF brings a significant improvement for general ROA
estimation problems, especially for non-symmetric or unbounded ROA, while
keeping the computational burden at a reasonable level. Its effectiveness and
advantages are demonstrated by several benchmark examples from literature.Comment: 40 pages, 9 figure
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