2,274 research outputs found
Quantum Dynamics of Mesoscopic Driven Duffing Oscillators
We investigate the nonlinear dynamics of a mesoscopic driven Duffing
oscillator in a quantum regime. In terms of Wigner function, we identify the
nature of state near the bifurcation point, and analyze the transient process
which reveals two distinct stages of quenching and escape. The rate process in
the escape stage allows us to extract the transition rate, which displays
perfect scaling behavior with the driving distance to the bifurcation point. We
numerically determine the scaling exponent, compare it with existing result,
and propose open questions to be resolved.Comment: 4 pages, 4 figures; revised version accepted for publication in EP
Rectified Pessimistic-Optimistic Learning for Stochastic Continuum-armed Bandit with Constraints
This paper studies the problem of stochastic continuum-armed bandit with
constraints (SCBwC), where we optimize a black-box reward function
subject to a black-box constraint function over a continuous space
. We model reward and constraint functions via Gaussian processes
(GPs) and propose a Rectified Pessimistic-Optimistic Learning framework (RPOL),
a penalty-based method incorporating optimistic and pessimistic GP bandit
learning for reward and constraint functions, respectively. We consider the
metric of cumulative constraint violation which is
strictly stronger than the traditional long-term constraint violation
The rectified design for the penalty update and the
pessimistic learning for the constraint function in RPOL guarantee the
cumulative constraint violation is minimal. RPOL can achieve sublinear regret
and cumulative constraint violation for SCBwC and its variants (e.g., under
delayed feedback and non-stationary environment). These theoretical results
match their unconstrained counterparts. Our experiments justify RPOL
outperforms several existing baseline algorithms
Accurate Estimation of Transport Coefficients Using Model-free Time Correlation Functions in Equilibrium Simulations
Transport coefficients, such as the diffusion coefficient and shear
viscosity, are important material properties that are calculated in computer
simulations. In this study, the criterion for the best estimation of viscosity,
as an example of transport coefficients, is determined by using the Green-Kubo
formula without any artificial models. The related algorithm is given by the
estimation of the viscosities of polyethylene oxide solutions by using a
molecular dynamics simulation for testing. The algorithm can be used in the
simulations of complex systems with a long tail of correlations typically found
in macromolecular and biological simulation systems.Comment: 8 pages, 5 figures, 1 tabl
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