The Experts below are selected from a list of 98040 Experts worldwide ranked by ideXlab platform
Richard H Henchman - One of the best experts on this subject based on the ideXlab platform.
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Energy Entropy prediction of octanol water logp of sampl7 n acyl sulfonamide bioisosters
Journal of Computer-aided Molecular Design, 2021Co-Authors: Fabio Falcioni, Jas Kalayan, Richard H HenchmanAbstract:Partition coefficients quantify a molecule’s distribution between two immiscible liquid phases. While there are many methods to compute them, there is not yet a method based on the free Energy of each system in terms of Energy and Entropy, where Entropy depends on the probability distribution of all quantum states of the system. Here we test a method in this class called Energy Entropy Multiscale Cell Correlation (EE-MCC) for the calculation of octanol–water logP values for 22 N-acyl sulfonamides in the SAMPL7 Physical Properties Challenge (Statistical Assessment of the Modelling of Proteins and Ligands). EE-MCC logP values have a mean error of 1.8 logP units versus experiment and a standard error of the mean of 1.0 logP units for three separate calculations. These errors are primarily due to getting sufficiently converged energies to give accurate differences of large numbers, particularly for the large-molecule solvent octanol. However, this is also an issue for Entropy, and approximations in the force field and MCC theory also contribute to the error. Unique to MCC is that it explains the Entropy contributions over all the degrees of freedom of all molecules in the system. A gain in orientational Entropy of water is the main favourable entropic contribution, supported by small gains in solute vibrational and orientational Entropy but offset by unfavourable changes in the orientational Entropy of octanol, the vibrational Entropy of both solvents, and the positional and conformational Entropy of the solute.
Jianzhong Zhou - One of the best experts on this subject based on the ideXlab platform.
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a multi step progressive fault diagnosis method for rolling element bearing based on Energy Entropy theory and hybrid ensemble auto encoder
Isa Transactions, 2019Co-Authors: Wei Jiang, Jianzhong Zhou, Yahui ShanAbstract:Abstract It is meaningful to efficiently identify the health status of bearing and automatically learn the effective features from the original vibration signals. In this paper, a multi-step progressive method based on Energy Entropy (EE) theory and hybrid ensemble auto-encoder (HEAE), systematically blending the statistical analysis approach with the deep learning technology, is proposed for rolling element bearing (REB) fault diagnosis. Firstly, a preliminary detection about the REB health status is performed by the statistical analysis technique integrated with the EE theory. Secondly, if fault exists in REB, a new HEAE is constructed based on denoising auto-encoder and contractive auto-encoder to strengthen the feature learning ability and automatically extract the deep state features from the raw data. Subsequently, a modified t-distributed stochastic neighbor embedding (M-tSNE) algorithm is developed to achieve the features reduction to further improve the diagnosis efficiency. Finally, the low-dimensional representations after features reduction are as the inputs of softmax classifier to recognize the fault conditions. The proposed method is applied to the fault diagnosis of REB. The results confirm the effectiveness and superiority of the proposed method, and it is more suitable for the actual engineering applications compared with other existing methods.
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multi fault diagnosis for rolling element bearings based on ensemble empirical mode decomposition and optimized support vector machines
Mechanical Systems and Signal Processing, 2013Co-Authors: Xiaoyuan Zhang, Jianzhong ZhouAbstract:Abstract This study presents a novel procedure based on ensemble empirical mode decomposition (EEMD) and optimized support vector machine (SVM) for multi-fault diagnosis of rolling element bearings. The vibration signal is adaptively decomposed into a number of intrinsic mode functions (IMFs) by EEMD. Two types of features, the EEMD Energy Entropy and singular values of the matrix whose rows are IMFs, are extracted. EEMD Energy Entropy is used to specify whether the bearing has faults or not. If the bearing has faults, singular values are input to multi-class SVM optimized by inter-cluster distance in the feature space (ICDSVM) to specify the fault type. The proposed method was tested on a system with an electric motor which has two rolling bearings with 8 normal working conditions and 48 fault working conditions. Five groups of experiments were done to evaluate the effectiveness of the proposed method. The results show that the proposed method outperforms other methods both mentioned in this paper and published in other literatures.
Guiqiang Chen - One of the best experts on this subject based on the ideXlab platform.
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vanishing viscosity solutions of the compressible euler equations with spherical symmetry and large initial data
Communications in Mathematical Physics, 2015Co-Authors: Guiqiang Chen, Mikhail PerepelitsaAbstract:We are concerned with spherically symmetric solutions of the Euler equations for multidimensional compressible fluids, which are motivated by many important physical situations. Various evidences indicate that spherically symmetric solutions of the compressible Euler equations may blow up near the origin at a certain time under some circumstance. The central feature is the strengthening of waves as they move radially inward. A longstanding open, fundamental problem is whether concentration could be formed at the origin. In this paper, we develop a method of vanishing viscosity and related estimate techniques for viscosity approximate solutions, and establish the convergence of the approximate solutions to a global finite-Energy Entropy solution of the isentropic Euler equations with spherical symmetry and large initial data. This indicates that concentration is not formed in the vanishing viscosity limit, even though the density may blow up at a certain time. To achieve this, we first construct global smooth solutions of appropriate initial-boundary value problems for the Euler equations with designed viscosity terms, approximate pressure function, and boundary conditions, and then we establish the strong convergence of the viscosity approximate solutions to a finite-Energy Entropy solution of the Euler equations.
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vanishing viscosity solutions of the compressible euler equations with spherical symmetry and large initial data
arXiv: Analysis of PDEs, 2014Co-Authors: Guiqiang Chen, Mikhail PerepelitsaAbstract:We are concerned with spherically symmetric solutions of the Euler equations for multidimensional compressible fluids, which are motivated by many important physical situations. Various evidences indicate that spherically symmetric solutions of the compressible Euler equations may blow up near the origin at certain time under some circumstance. The central feature is the strengthening of waves as they move radially inward. A longstanding open, fundamental question is whether concentration could form at the origin. In this paper, we develop a method of vanishing viscosity and related estimate techniques for viscosity approximate solutions, and establish the convergence of the approximate solutions to a global finite-Energy Entropy solution of the compressible Euler equations with spherical symmetry and large initial data. This indicates that concentration does not form in the vanishing viscosity limit, even though the density may blow up at certain time. To achieve this, we first construct global smooth solutions of appropriate initial-boundary value problems for the Euler equations with designed viscosity terms, an approximate pressure function, and boundary conditions, and then we establish the strong convergence of the viscosity approximate solutions to a finite-Energy Entropy solutions of the Euler equations.
Mikhail Perepelitsa - One of the best experts on this subject based on the ideXlab platform.
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vanishing viscosity solutions of the compressible euler equations with spherical symmetry and large initial data
Communications in Mathematical Physics, 2015Co-Authors: Guiqiang Chen, Mikhail PerepelitsaAbstract:We are concerned with spherically symmetric solutions of the Euler equations for multidimensional compressible fluids, which are motivated by many important physical situations. Various evidences indicate that spherically symmetric solutions of the compressible Euler equations may blow up near the origin at a certain time under some circumstance. The central feature is the strengthening of waves as they move radially inward. A longstanding open, fundamental problem is whether concentration could be formed at the origin. In this paper, we develop a method of vanishing viscosity and related estimate techniques for viscosity approximate solutions, and establish the convergence of the approximate solutions to a global finite-Energy Entropy solution of the isentropic Euler equations with spherical symmetry and large initial data. This indicates that concentration is not formed in the vanishing viscosity limit, even though the density may blow up at a certain time. To achieve this, we first construct global smooth solutions of appropriate initial-boundary value problems for the Euler equations with designed viscosity terms, approximate pressure function, and boundary conditions, and then we establish the strong convergence of the viscosity approximate solutions to a finite-Energy Entropy solution of the Euler equations.
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vanishing viscosity solutions of the compressible euler equations with spherical symmetry and large initial data
arXiv: Analysis of PDEs, 2014Co-Authors: Guiqiang Chen, Mikhail PerepelitsaAbstract:We are concerned with spherically symmetric solutions of the Euler equations for multidimensional compressible fluids, which are motivated by many important physical situations. Various evidences indicate that spherically symmetric solutions of the compressible Euler equations may blow up near the origin at certain time under some circumstance. The central feature is the strengthening of waves as they move radially inward. A longstanding open, fundamental question is whether concentration could form at the origin. In this paper, we develop a method of vanishing viscosity and related estimate techniques for viscosity approximate solutions, and establish the convergence of the approximate solutions to a global finite-Energy Entropy solution of the compressible Euler equations with spherical symmetry and large initial data. This indicates that concentration does not form in the vanishing viscosity limit, even though the density may blow up at certain time. To achieve this, we first construct global smooth solutions of appropriate initial-boundary value problems for the Euler equations with designed viscosity terms, an approximate pressure function, and boundary conditions, and then we establish the strong convergence of the viscosity approximate solutions to a finite-Energy Entropy solutions of the Euler equations.
Matthias Troyer - One of the best experts on this subject based on the ideXlab platform.
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neel temperature and thermodynamics of the half filled three dimensional hubbard model by diagrammatic determinant monte carlo
Physical Review B, 2013Co-Authors: Evgeny Kozik, Evgeni Burovski, V W Scarola, Matthias TroyerAbstract:We study thermodynamics of the 3D Hubbard model at half filling on approach to the N\'eel transition by means of large-scale unbiased Diagrammatic Determinant Monte Carlo simulations. We obtain the transition temperature in the strongly correlated regime, as well as temperature dependence of Energy, Entropy, double occupancy, and the nearest-neighbor spin correlation function. Our results improve the accuracy of previous unbiased studies and present accurate benchmarks in the ongoing effort to realize the antiferromagnetic state of matter with ultracold atoms in optical lattices.
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neel temperature and thermodynamics of the half filled three dimensional hubbard model by diagrammatic determinant monte carlo
Physical Review B, 2013Co-Authors: Evgeny Kozik, Evgeni Burovski, V W Scarola, Matthias TroyerAbstract:We study the thermodynamics of the three-dimensional Hubbard model at half filling on approach to the N\'eel transition by means of large-scale unbiased diagrammatic determinant Monte Carlo simulations. We obtain the transition temperature in the strongly correlated regime, as well as the temperature dependence of the Energy, Entropy, double occupancy, and nearest-neighbor spin correlation function. Our results improve the accuracy of previous unbiased studies and present accurate benchmarks in the ongoing effort to realize the antiferromagnetic state of matter with ultracold atoms in optical lattices.