525 research outputs found
Magnetic Field Effect on Charmonium Production in High Energy Nuclear Collisions
It is important to understand the strong external magnetic field generated at
the very beginning of high energy nuclear collisions. We study the effect of
the magnetic field on the charmonium yield and anisotropic distribution in
Pb+Pb collisions at the LHC energy. The time dependent Schr\"odinger equation
is employed to describe the motion of pairs. We compare our model
prediction of non- collective anisotropic parameter of s with CMS
data at high transverse momentum. This is the first attempt to measure the
magnetic field in high energy nuclear collisions.Comment: 5 pages, 4 figure
Cloud-Based Dynamic Programming for an Electric City Bus Energy Management Considering Real-Time Passenger Load Prediction
Electric city bus gains popularity in recent years for its low greenhouse gas
emission, low noise level, etc. Different from a passenger car, the weight of a
city bus varies significantly with different amounts of onboard passengers,
which is not well studied in existing literature. This study proposes a
passenger load prediction model using day-of-week, time-of-day, weather,
temperatures, wind levels, and holiday information as inputs. The average
model, Regression Tree, Gradient Boost Decision Tree, and Neural Networks
models are compared in the passenger load prediction. The Gradient Boost
Decision Tree model is selected due to its best accuracy and high stability.
Given the predicted passenger load, dynamic programming algorithm determines
the optimal power demand for supercapacitor and battery by optimizing the
battery aging and energy usage in the cloud. Then rule extraction is conducted
on dynamic programming results, and the rule is real-time loaded to onboard
controllers of vehicles. The proposed cloud-based dynamic programming and rule
extraction framework with the passenger load prediction shows 4% and 11% fewer
bus operating costs in off-peak and peak hours, respectively. The operating
cost by the proposed framework is less than 1% shy of the dynamic programming
with the true passenger load information
Reinforcement Learning for Self-exploration in Narrow Spaces
In narrow spaces, motion planning based on the traditional hierarchical
autonomous system could cause collisions due to mapping, localization, and
control noises. Additionally, it is disabled when mapless. To tackle these
problems, we leverage deep reinforcement learning which is verified to be
effective in self-decision-making, to self-explore in narrow spaces without a
map while avoiding collisions. Specifically, based on our Ackermann-steering
rectangular-shaped ZebraT robot and its Gazebo simulator, we propose the
rectangular safety region to represent states and detect collisions for
rectangular-shaped robots, and a carefully crafted reward function for
reinforcement learning that does not require the destination information. Then
we benchmark five reinforcement learning algorithms including DDPG, DQN, SAC,
PPO, and PPO-discrete, in a simulated narrow track. After training, the
well-performed DDPG and DQN models can be transferred to three brand new
simulated tracks, and furthermore to three real-world tracks
The Color Octet Effect from at B Factory
We study the initial state radiation process
for production at B factory, and find the cross section is 61% larger
than it's Born one for color octet part and is about half as it's Born one for
color singlet part. Furthermore, the color singlet and color octet signal are
very clearly separated in it's spectra due to kinematics difference.
We suggest to measure this spectra at B factory to determine the
color octet effect.Comment: 4 pages, 4 figures and 1 tabl
Explainable Topic-Enhanced Argument Mining from Heterogeneous Sources
Given a controversial target such as ``nuclear energy'', argument mining aims
to identify the argumentative text from heterogeneous sources. Current
approaches focus on exploring better ways of integrating the target-associated
semantic information with the argumentative text. Despite their empirical
successes, two issues remain unsolved: (i) a target is represented by a word or
a phrase, which is insufficient to cover a diverse set of target-related
subtopics; (ii) the sentence-level topic information within an argument, which
we believe is crucial for argument mining, is ignored. To tackle the above
issues, we propose a novel explainable topic-enhanced argument mining approach.
Specifically, with the use of the neural topic model and the language model,
the target information is augmented by explainable topic representations.
Moreover, the sentence-level topic information within the argument is captured
by minimizing the distance between its latent topic distribution and its
semantic representation through mutual learning. Experiments have been
conducted on the benchmark dataset in both the in-target setting and the
cross-target setting. Results demonstrate the superiority of the proposed model
against the state-of-the-art baselines.Comment: 10 pages, 3 figure
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