284 research outputs found
Signatures of quantum chaos of Rydberg dressed bosons in a triple-well potential
We study signatures of quantum chaos in dynamics of Rydberg dressed bosonic
atoms held in a one dimensional triple-well potential. Long-range
nearest-neighbor and next-nearest-neighbor interactions, induced by laser
dressing atoms to strongly interacting Rydberg states, affect drastically mean
field and quantum many-body dynamics. By analyzing the mean field dynamics,
classical chaos regions with positive and large Lyapunov exponents are
identified as a function of the potential well tilting and dressed
interactions. In the quantum regime, it is found that level statistics of the
eigen-energies gains a Wigner-Dyson distribution when the Lyapunov exponents
are large, giving rise to signatures of strong quantum chaos. We find that both
the time averaged entanglement entropy and survival probability of the initial
state have distinctively large values in the quantum chaos regime. We further
show that population variances could be used as an indicator of the emergence
of quantum chaos. This might provide a way to directly probe quantum chaotic
dynamics through analyzing population dynamics in individual potential wells
IGN : Implicit Generative Networks
In this work, we build recent advances in distributional reinforcement
learning to give a state-of-art distributional variant of the model based on
the IQN. We achieve this by using the GAN model's generator and discriminator
function with the quantile regression to approximate the full quantile value
for the state-action return distribution. We demonstrate improved performance
on our baseline dataset - 57 Atari 2600 games in the ALE. Also, we use our
algorithm to show the state-of-art training performance of risk-sensitive
policies in Atari games with the policy optimization and evaluation
Robust Natural Language Understanding with Residual Attention Debiasing
Natural language understanding (NLU) models often suffer from unintended
dataset biases. Among bias mitigation methods, ensemble-based debiasing
methods, especially product-of-experts (PoE), have stood out for their
impressive empirical success. However, previous ensemble-based debiasing
methods typically apply debiasing on top-level logits without directly
addressing biased attention patterns. Attention serves as the main media of
feature interaction and aggregation in PLMs and plays a crucial role in
providing robust prediction. In this paper, we propose REsidual Attention
Debiasing (READ), an end-to-end debiasing method that mitigates unintended
biases from attention. Experiments on three NLU tasks show that READ
significantly improves the performance of BERT-based models on OOD data with
shortcuts removed, including +12.9% accuracy on HANS, +11.0% accuracy on
FEVER-Symmetric, and +2.7% F1 on PAWS. Detailed analyses demonstrate the
crucial role of unbiased attention in robust NLU models and that READ
effectively mitigates biases in attention. Code is available at
https://github.com/luka-group/READ.Comment: ACL 2023 Finding
Synthesis and antibacterial activity evaluation of aminoguanidine or dihydrotriazine derivatives
In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. In this article, aminoguanidine and dihydrotriazine derivatives were designed, synthesized and evaluated in terms of their antibacterial and antifungal activities. Most of the synthesized compounds showed potent inhibitory activities against different bacteria and one fungus with minimum inhibitory concentrations (MICs) ranging from 1 to 64 μg/mL, which obviously better than the positives control drug. The compound 23a showed the best antibacterial activities, whose MIC value was 1 μg/mL against eight strains. The cytotoxic activity of the compound 4c, 8a and 23a were assessed in Human liver cancer cells. The preliminary docking results imply that compounds 21b and 23a possibly display their antibacterial activity through the interaction with DHFR protein by targeting residues of the active cavities of DHFR
Synthesis and antibacterial activity evaluation of aminoguanidine or dihydrotriazine derivatives
301-308In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. In this article, aminoguanidine and dihydrotriazine derivatives were designed, synthesized and evaluated in terms of their antibacterial and antifungal activities. Most of the synthesized compounds showed potent inhibitory activities against different bacteria and one fungus with minimum inhibitory concentrations (MICs) ranging from 1 to 64 μg/mL, which obviously better than the positives control drug. The compound 23a showed the best antibacterial activities, whose MIC value was 1 μg/mL against eight strains. The cytotoxic activity of the compound 4c, 8a and 23a were assessed in Human liver cancer cells. The preliminary docking results imply that compounds 21b and 23a possibly display their antibacterial activity through the interaction with DHFR protein by targeting residues of the active cavities of DHFR
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