4,484 research outputs found
A thermodynamically consistent quasi-particle model without density-dependent infinity of the vacuum zero point energy
In this paper, we generalize the improved quasi-particle model proposed in J.
Cao et al., [ Phys. Lett. B {\bf711}, 65 (2012)] from finite temperature and
zero chemical potential to the case of finite chemical potential and zero
temperature, and calculate the equation of state (EOS) for (2+1) flavor Quantum
Chromodynamics (QCD) at zero temperature and high density. We first calculate
the partition function at finite temperature and chemical potential, then go to
the limit and obtain the equation of state (EOS) for cold and dense QCD,
which is important for the study of neutron stars. Furthermore, we use this EOS
to calculate the quark-number density, the energy density, the quark-number
susceptibility and the speed of sound at zero temperature and finite chemical
potential and compare our results with the corresponding ones in the existing
literature
Causality-based Neural Network Repair
Neural networks have had discernible achievements in a wide range of
applications. The wide-spread adoption also raises the concern of their
dependability and reliability. Similar to traditional decision-making programs,
neural networks can have defects that need to be repaired. The defects may
cause unsafe behaviors, raise security concerns or unjust societal impacts. In
this work, we address the problem of repairing a neural network for desirable
properties such as fairness and the absence of backdoor. The goal is to
construct a neural network that satisfies the property by (minimally) adjusting
the given neural network's parameters (i.e., weights). Specifically, we propose
CARE (\textbf{CA}usality-based \textbf{RE}pair), a causality-based neural
network repair technique that 1) performs causality-based fault localization to
identify the `guilty' neurons and 2) optimizes the parameters of the identified
neurons to reduce the misbehavior. We have empirically evaluated CARE on
various tasks such as backdoor removal, neural network repair for fairness and
safety properties. Our experiment results show that CARE is able to repair all
neural networks efficiently and effectively. For fairness repair tasks, CARE
successfully improves fairness by on average. For backdoor removal
tasks, CARE reduces the attack success rate from over to less than
. For safety property repair tasks, CARE reduces the property violation
rate to less than . Results also show that thanks to the causality-based
fault localization, CARE's repair focuses on the misbehavior and preserves the
accuracy of the neural networks
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