We propose a new strategy for Monte Carlo (MC) optimization on rugged multidimensional landscapes. The strategy is based on querying the statistical properties of the landscape in order to find the temperature at which the mean first passage time across the current region of the landscape is minimized. Thus, in contrast to other algorithms such as simulated annealing, we explicitly match the temperature schedule to the statistics of landscape irregularities. In cases where these statistics are approximately the same over the entire landscape or where nonlocal moves couple distant parts of the landscape, a single-temperature MC scheme outperforms any other MC algorithm with the same move set. We also find that in strongly anisotropic Coulomb spin glass and traveling salesman problems, the only relevant statistics (which we use to assign a single MC temperature) are those of irregularities in low-energy funnels. Our results may explain why protein folding is efficient at constant temperature.
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http://dx.doi.org/10.1103/PhysRevLett.108.250602 | DOI Listing |
Sci Rep
December 2024
Laboratorio de Fluidodinámica, Facultad de Ingeniería, Universidad de Buenos Aires/CONICET, Paseo Colón 850 CABA, Buenos Aires, Argentina.
The oil and gas industry faces two significant challenges, including rising global temperatures and depletion of reserves. Enhanced recovery techniques such as polymer flooding have positioned themselves as an alternative that attracts international attention thanks to increased recovery factors with low emissions. However, existing physical models need further refinement to improve predictive accuracy and prevent design failures in polymer flooding projects.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
This paper presents progress made toward the overarching goal to adapt single-photon-counting microcalorimeters to magnetic fusion energy research and demonstrate the value of such measurements for fusion. Microcalorimeter spectrometers combine the best characteristics of x-ray instrumentation currently available on fusion devices: high spectral resolution similar to an x-ray crystal spectrometer and broad spectral coverage sufficient to measure impurity species from Be to W. As a proof-of-principle experiment, a NASA-built x-ray microcalorimeter spectrometer has been installed on the Madison Symmetric Torus (MST) at the Wisconsin Plasma Physics Laboratory.
View Article and Find Full Text PDFBMC Mol Cell Biol
December 2024
Department of Biomedical and Molecular Sciences, Queen's University, Botterell Hall, 18 Stuart Street, Kingston, K7L 3N6, Canada.
Alanine-rich, alpha-helical type I antifreeze proteins (AFPs) in fishes are thought to have arisen independently in the last 30 Ma on at least four occasions. This hypothesis has recently been proven for flounder and sculpin AFPs, which both originated by gene duplication and divergence followed by substantial gene copy number expansion. Here, we examined the origins of the cunner (wrasse) and snailfish (liparid) AFPs.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Hefei National Research Center for Physical Sciences at the Microscale, Department of Materials Science and Engineering, School of Chemistry and Materials Science, Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.
High-temperature graphitization of graphene oxide (GO) is a crucial step for enhancing interlayer stacking and repairing the in-plane defects of reduced graphene oxide (rGO) films. However, the fine control of the structural repair and reducing the energy consumption in thermal treatment remain challenges. In this study, ab-initio molecular dynamics simulations combined with experiments are used to investigate the structural evolution of rGO upon thermal annealing, with or without the presence of single-layer graphene (SLG).
View Article and Find Full Text PDFHeliyon
December 2024
Department of Hydraulic and Water Resource Engineering, Jimma University Institute of Technology, P.O. Box 378, Jimma, Ethiopia.
Understanding climate science is essential for effective policy development, adaptation, mitigation, and risk management. Given the inherent limitations in climate models, this study evaluates the performance of CORDEX Africa regional climate models to simulate precipitation and temperatures over the Melka-Wakena catchment. To accomplish this, the performance evaluation utilizes techniques such as multi-metric weighted ranking to select top-1 (best individual model), specific multi-model ensembles (top-N ensemble), multi-model ensemble, and average hybrid (top-N ensemble with MME) approaches at various temporal scales.
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