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951.
952.
In many practical optimization problems, evaluation of a solution is subject to noise, e.g., due to stochastic simulations
or measuring errors. Therefore, heuristics are needed that are capable of handling such noise. This paper first reviews the
state-of-the-art in applying simulated annealing to noisy optimization problems. Then, two new algorithmic variants are proposed:
an improved version of stochastic annealing that allows for arbitrary annealing schedules, and a new approach called simulated annealing in noisy environments (SANE). The latter integrates ideas from statistical sequential selection in order to reduce the number of samples required
for making an acceptance decision with sufficient statistical confidence. Finally, SANE is shown to significantly outperform
other state-of-the-art simulated annealing techniques on a stochastic travelling salesperson problem. 相似文献
953.
954.
N. Nücker P. Adelmann M. Alexander H. Romberg S. Nakai J. Fink H. Rietschel G. Roth H. Schmidt H. Spille 《Zeitschrift für Physik B Condensed Matter》1989,75(4):421-422
We present results from electron energy-loss spectroscopy on Nd2–xCexCuO4. There is no clear evidence for Cu1+ but for holes at the oxygen sites. The valency of Ce is found to be close to 3.4. Thus our results do not corroboraten-type superconductivity in this compound. 相似文献
955.
We have studied some energetic and structural ground state properties of a spinless Falicov-Kimball model. Using a method based on “Tchebycheff-Markoff inequalities”, we have calculated sharp upper and lower bounds for the ground state energy. These calculations lead to rigorous results for a special range of parameters, where we are able to give the exactf-level occupation pattern for a square lattice. The results for the “symmetric” case, where a superstructure occurs leading to a metal-insulator transition, have already been published. In this paper we present some additional results also for the “unsymmetric case” and study valence-transitions for fixed particle-number. 相似文献
956.
957.
958.
Probabilistic predictions with machine learning are important in many applications. These are commonly done with Bayesian learning algorithms. However, Bayesian learning methods are computationally expensive in comparison with non-Bayesian methods. Furthermore, the data used to train these algorithms are often distributed over a large group of end devices. Federated learning can be applied in this setting in a communication-efficient and privacy-preserving manner but does not include predictive uncertainty. To represent predictive uncertainty in federated learning, our suggestion is to introduce uncertainty in the aggregation step of the algorithm by treating the set of local weights as a posterior distribution for the weights of the global model. We compare our approach to state-of-the-art Bayesian and non-Bayesian probabilistic learning algorithms. By applying proper scoring rules to evaluate the predictive distributions, we show that our approach can achieve similar performance as the benchmark would achieve in a non-distributed setting. 相似文献
959.
In this article, we describe the basic principles of luminescence dating, for which knowledge and methods of solid state physics and radiochemistry play a major role. The type of dated event – the last heating or daylight exposure – opens up a broad spectrum of applications of this method for periods ranging from 102 up to several 105 years. Through the cooperation of dating specialists with geoscientists and archaeologists, luminescence dating is nowadays an essential tool for addressing problems in Earth‐science and human history. 相似文献
960.
Antony V. Wilson Timothy Nguyen Felix Brosi Xuefeng Wang Lester Andrews Sebastian Riedel Adam J. Bridgeman Nigel A. Young 《ChemInform》2016,47(14):no-no
Binary palladium fluorides from PdF to PdF6 are investigated by matrix‐isolation methods using thermal evaporation and laser ablation to generate Pd atoms for reaction with F2‐doped Ar and Ne matrices as well as neat F2 matrices. 相似文献