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Ab initio thermodynamics of the CoCrFeMnNi high entropy alloy: Importance of entropy contributions beyond the configurational one KU Leuven

Dierk Raabe
© 2015 Acta Materialia Inc. We investigate the thermodynamic properties of the prototype equi-atomic high entropy alloy (HEA) CoCrFeMnNi by using finite-temperature ab initio methods. All relevant free energy contributions are considered for the hcp, fcc, and bcc structures, including electronic, vibrational, and magnetic excitations. We predict the paramagnetic fcc phase to be most stable above room temperature in agreement with experiment. The ...

Acceleration of Bucket-Assisted Fast Sample Entropy for Biomedical Signal Analysis Vrije Universiteit Brussel

Chao Chen, Chengyu Liu, Jianqing Li, Bruno da Silva
Sample Entropy (SampEn) is widely used to assess the complexity of physiological time-series signals. However, it is a computationally intensive algorithm with O(N2) time complexity. Although algorithmic optimizations, such as Bucket-Assisted SampEn, have been proposed to eliminate unnecessary computations, the time demand restricts their use in real-time applications with long-term inputs. To address the time and space complexity issue in ...

A maximum entropy approach for the evaluation of surrogate endpoints based on causal inference Universiteit Hasselt KU Leuven

Ariel ALONSO ABAD, Wim VAN DER ELST, Geert MOLENBERGHS
The maximum entropy principle offers a constructive criterion for setting up probability distributions on the basis of partial knowledge. In the present work, the principle is applied to tackle an important problem in the surrogate marker field, namely, the evaluation of a binary outcome as a putative surrogate for a binary true endpoint within a causal inference framework. In the first step, the maximum entropy principle is used to determine ...

Multiscale entropy as a metric of brain maturation in a large cohort of typically developing children born preterm using longitudinal high-density EEG in the first two years of life Vrije Universiteit Brussel KU Leuven

Karine Pelc, Aleksandra Gajewska, Natan Napiórkowski, Jonathan Dan, Caroline Verhoeven, Bernard Dan

Objective.We aimed to analyze whether complexity of brain electrical activity (EEG) measured by multiscale entropy (MSE) increases with brain maturation during the first two years of life. We also aimed to investigate whether this complexity shows regional differences across the brain, and whether changes in complexity are influenced by extrauterine life experience duration.Approach.We measured MSE of EEG signals recorded longitudinally using ...

Intrasubject multimodal groupwise registration with the conditional template entropy Vrije Universiteit Brussel

Mathias Polfliet, Stefan Klein, Margarethus M. Paulides, Wiro J. Niessen, Jef Vandemeulebroucke

Image registration is an important task in medical image analysis. Whereas most methods are designed for the registration of two images (pairwise registration), there is an increasing interest in simultaneously aligning more than two images using groupwise registration. Multimodal registration in a groupwise setting remains difficult, due to the lack of generally applicable similarity metrics. In this work, a novel similarity metric for such ...

Rearrangement algorithm and maximum entropy Vrije Universiteit Brussel

Carole Bernard, Oleg Bondarenko, Steven Vanduffel

We study properties of the block rearrangement algorithm (BRA) in the context of inferring dependence among variables given their marginal distributions and the distribution of their sum. We show that when all distributions are Gaussian the BRA yields solutions that are “close to each other” and exhibit almost maximum entropy, i.e., the inferred dependence is Gaussian with a correlation matrix that has maximum possible determinant. We provide ...