1,462 research outputs found
Sensor/ROIC Integration using Oxide Bonding
We explore the Ziptronix Direct Bond Interconnect technology for the
integration of sensors and readout integrated circuits (ROICs) for high energy
physics. The technology utilizes an oxide bond to form a robust mechanical
connection between layers which serves to assist with the formation of metallic
interlayer connections. We report on testing results of sample sensors bonded
to ROICs and thinned to 100 microns.Comment: Talk given at the 2008 International Linear Collider Workshop (LCWS08
and ILC08), Chicago, Illinois, November 16-20, 2008. 4 pages, 1 figur
Investigation of the elliptic flow fluctuations of the identified particles using the A Multi-Phase Transport model
A Multi-Phase Transport (AMPT) model is used to study the elliptic flow
fluctuations of identified particles using participant and spectator event
planes. The elliptic flow measured using the first order spectator event plane
is expected to give the elliptic flow relative to the true reaction plane which
suppresses the flow fluctuations. However, the elliptic flow measured using the
second-order participant plane is expected to capture the elliptic flow
fluctuations. Our study shows that the first order spectator event plane could
be used to study the elliptic flow fluctuations of the identified particles in
the AMPT model. The elliptic flow fluctuations magnitude shows weak particle
species dependence and transverse momentum dependence. Such observation will
have important implications for understanding the source of the elliptic flow
fluctuations.Comment: 7 pages, 4 figure
HOFA: Twitter Bot Detection with Homophily-Oriented Augmentation and Frequency Adaptive Attention
Twitter bot detection has become an increasingly important and challenging
task to combat online misinformation, facilitate social content moderation, and
safeguard the integrity of social platforms. Though existing graph-based
Twitter bot detection methods achieved state-of-the-art performance, they are
all based on the homophily assumption, which assumes users with the same label
are more likely to be connected, making it easy for Twitter bots to disguise
themselves by following a large number of genuine users. To address this issue,
we proposed HOFA, a novel graph-based Twitter bot detection framework that
combats the heterophilous disguise challenge with a homophily-oriented graph
augmentation module (Homo-Aug) and a frequency adaptive attention module
(FaAt). Specifically, the Homo-Aug extracts user representations and computes a
k-NN graph using an MLP and improves Twitter's homophily by injecting the k-NN
graph. For the FaAt, we propose an attention mechanism that adaptively serves
as a low-pass filter along a homophilic edge and a high-pass filter along a
heterophilic edge, preventing user features from being over-smoothed by their
neighborhood. We also introduce a weight guidance loss to guide the frequency
adaptive attention module. Our experiments demonstrate that HOFA achieves
state-of-the-art performance on three widely-acknowledged Twitter bot detection
benchmarks, which significantly outperforms vanilla graph-based bot detection
techniques and strong heterophilic baselines. Furthermore, extensive studies
confirm the effectiveness of our Homo-Aug and FaAt module, and HOFA's ability
to demystify the heterophilous disguise challenge.Comment: 11 pages, 7 figure
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