The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Mohamadreza Fazel - One of the best experts on this subject based on the ideXlab platform.

  • Hessian Matrix, specific heats, Nambu brackets, and thermodynamic geometry
    Journal of High Energy Physics, 2015
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    (Dated: November 8, 2014)As an extension to our earlier work [1], we employ the Nambu brackets to prove that the diver-gences of heat capacities correspond to their counterparts in thermodynamic geometry. We alsoobtain a simple representation for the conformal transformations that connect di erent thermody-namics metrics to each other. Using our bracket approach, we obtain interesting exact relationsbetween the Hessian Matrix with any number of parameters and speci c heat capacities. Finally,we employ this approach to investigate some thermodynamic properties of the Meyers-Perry blackholes with three spins.I. INTRODUCTION

  • Hessian Matrix specific heats nambu brackets and thermodynamic geometry
    arXiv: General Relativity and Quantum Cosmology, 2014
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    As an extension to our earlier work \cite{Mirza2}, we employ the Nambu brackets to prove that the divergences of heat capacities correspond to their counterparts in thermodynamic geometry. We also obtain a simple representation for the conformal transformations that connect different thermodynamics metrics to each other. Using our bracket approach, we obtain interesting exact relations between the Hessian Matrix with any number of parameters and specific heat capacities. Finally, we employ this approach to investigate some thermodynamic properties of the Meyers-Perry black holes with three spins.

Qimao Liu - One of the best experts on this subject based on the ideXlab platform.

  • Sensitivity and Hessian Matrix analysis of structural reliability for uniformly modulated random seismic response.
    Mechanics Research Communications, 2014
    Co-Authors: Qimao Liu, Juha Paavola
    Abstract:

    Abstract This paper presents a numerical method for calculation of the sensitivity and Hessian Matrix of the time variant reliability of structures subjected to uniformly modulated evolutionary random seismic excitation. The first three spectral moments, their first and second derivatives are obtained using the auto PSD functions, their sensitivity and Hessian Matrix information. The formulas of the first and second derivatives of reliability are derived by direct differentiation based on the reliability formula that assumes the threshold crossings to obey a two-state Markov process. The computational procedure is given in detail for the reliability, its first and second derivatives. Finally, the reliability, its sensitivity and Hessian Matrix analysis of a planar frame subjected to the uniformly modulated evolutionary random earthquake ground motion has been studied to elucidate the proposed method. The accuracy and efficiency of the proposed method in this paper are discussed by comparison with the developed method.

  • Sensitivity and Hessian Matrix Analysis of Evolutionary PSD Functions for Nonstationary Random Seismic Responses
    Journal of Engineering Mechanics, 2012
    Co-Authors: Qimao Liu
    Abstract:

    AbstractThis paper describes a numerical method for calculation of the sensitivity and Hessian Matrix of the response evolutionary power spectral density (PSD) functions of structures subjected to uniformly modulated evolutionary random seismic excitation. The method is formulated based on the pseudoexcitation method and the Gauss precise time step integration method. The evolutionary nonstationary random response analysis is converted into step-by-step integration computations using the pseudoexcitation method. The formulas of the pseudoresponses and their first and second derivatives with respect to the structural design variables are derived based on the Gauss precise time step integration method. The evolutionary PSD functions, their sensitivity, and the Hessian Matrix are calculated using the pseudoresponses and their first and second derivatives, respectively. Finally, the evolutionary PSD functions’ sensitivity and Hessian Matrix analysis of a three-story, two-bay planar frame subjected to uniforml...

  • Sensitivity and Hessian Matrix analysis of power spectral density functions for uniformly modulated evolutionary random seismic responses
    Finite Elements in Analysis and Design, 2012
    Co-Authors: Qimao Liu
    Abstract:

    This paper describes a numerical method for calculation of the sensitivity and Hessian Matrix of the response PSD functions of structures subjected to uniformly modulated evolutionary random seismic excitation. The method is formulated based on the pseudo excitation method and Newmark method. The evolutionary non-stationary random response analysis is converted into step-by-step integration computations using the pseudo excitation method. The formulas of the pseudo responses, their first and second derivatives with respect to the structural design variables are derived based on the Newmark method. The PSD functions, their sensitivity and Hessian Matrix are calculated using the pseudo responses, their first and second derivatives, respectively. Then the computation procedure of sensitivity and Hessian Matrix of PSD functions is given in detail. Finally, the PSD functions' sensitivity and Hessian Matrix analysis of a three-story, two-bay planar frame subjected to the uniformly modulated evolutionary random earthquake ground motion has been studied to elucidate the proposed method.

  • Response sensitivity and Hessian Matrix analysis of planar frames subjected to earthquake excitation
    Finite Elements in Analysis and Design, 2009
    Co-Authors: Qimao Liu, Jing Zhang, Liubin Yan
    Abstract:

    This paper describes a new method of calculating accurately and efficiently dynamic response sensitivity and Hessian Matrix of planar frames subjected to earthquake excitation. The formulas for sensitivity and Hessian Matrix are derived by direct differentiation. An efficient algorithm to calculate dynamic response sensitivity and Hessian Matrix is formulated based on finite element method and Newmark-@b method. The first and second derivatives of dynamic responses can be derived simultaneously with only a single dynamics analysis. Two numerical examples are demonstrated with the newly developed method and the central-difference method. The results show that compared with the central-difference method, the new method proposed in this paper is highly accurate and more efficient.

Seyed Ali Hosseini Mansoori - One of the best experts on this subject based on the ideXlab platform.

  • Hessian Matrix, specific heats, Nambu brackets, and thermodynamic geometry
    Journal of High Energy Physics, 2015
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    (Dated: November 8, 2014)As an extension to our earlier work [1], we employ the Nambu brackets to prove that the diver-gences of heat capacities correspond to their counterparts in thermodynamic geometry. We alsoobtain a simple representation for the conformal transformations that connect di erent thermody-namics metrics to each other. Using our bracket approach, we obtain interesting exact relationsbetween the Hessian Matrix with any number of parameters and speci c heat capacities. Finally,we employ this approach to investigate some thermodynamic properties of the Meyers-Perry blackholes with three spins.I. INTRODUCTION

  • Hessian Matrix specific heats nambu brackets and thermodynamic geometry
    arXiv: General Relativity and Quantum Cosmology, 2014
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    As an extension to our earlier work \cite{Mirza2}, we employ the Nambu brackets to prove that the divergences of heat capacities correspond to their counterparts in thermodynamic geometry. We also obtain a simple representation for the conformal transformations that connect different thermodynamics metrics to each other. Using our bracket approach, we obtain interesting exact relations between the Hessian Matrix with any number of parameters and specific heat capacities. Finally, we employ this approach to investigate some thermodynamic properties of the Meyers-Perry black holes with three spins.

Behrouz Mirza - One of the best experts on this subject based on the ideXlab platform.

  • Hessian Matrix, specific heats, Nambu brackets, and thermodynamic geometry
    Journal of High Energy Physics, 2015
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    (Dated: November 8, 2014)As an extension to our earlier work [1], we employ the Nambu brackets to prove that the diver-gences of heat capacities correspond to their counterparts in thermodynamic geometry. We alsoobtain a simple representation for the conformal transformations that connect di erent thermody-namics metrics to each other. Using our bracket approach, we obtain interesting exact relationsbetween the Hessian Matrix with any number of parameters and speci c heat capacities. Finally,we employ this approach to investigate some thermodynamic properties of the Meyers-Perry blackholes with three spins.I. INTRODUCTION

  • Hessian Matrix specific heats nambu brackets and thermodynamic geometry
    arXiv: General Relativity and Quantum Cosmology, 2014
    Co-Authors: Seyed Ali Hosseini Mansoori, Behrouz Mirza, Mohamadreza Fazel
    Abstract:

    As an extension to our earlier work \cite{Mirza2}, we employ the Nambu brackets to prove that the divergences of heat capacities correspond to their counterparts in thermodynamic geometry. We also obtain a simple representation for the conformal transformations that connect different thermodynamics metrics to each other. Using our bracket approach, we obtain interesting exact relations between the Hessian Matrix with any number of parameters and specific heat capacities. Finally, we employ this approach to investigate some thermodynamic properties of the Meyers-Perry black holes with three spins.

George D C Cavalcanti - One of the best experts on this subject based on the ideXlab platform.

  • retinal vessel segmentation using average of synthetic exact filters and Hessian Matrix
    International Conference on Image Processing, 2012
    Co-Authors: Wendeson S Oliveira, Tsang Ing Ren, George D C Cavalcanti
    Abstract:

    The segmentation of blood vessels in retinal images is an important procedure for the prediction and diagnosis of cardiovascular diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels appearance. This work aims to develop an effective method of retinal vessels segmentation by combining correlation filters and measures extracted from the eigenvalues of the Hessian Matrix. The approach uses a threshold to segment the image generated by this combination and is evaluated on two public image databases, Drive and Stare. The results are compared to other state-of-the-art methods described in the literature.

  • ICIP - Retinal vessel segmentation using Average of Synthetic Exact Filters and Hessian Matrix
    2012 19th IEEE International Conference on Image Processing, 2012
    Co-Authors: Wendeson S Oliveira, Tsang Ing Ren, George D C Cavalcanti
    Abstract:

    The segmentation of blood vessels in retinal images is an important procedure for the prediction and diagnosis of cardiovascular diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels appearance. This work aims to develop an effective method of retinal vessels segmentation by combining correlation filters and measures extracted from the eigenvalues of the Hessian Matrix. The approach uses a threshold to segment the image generated by this combination and is evaluated on two public image databases, Drive and Stare. The results are compared to other state-of-the-art methods described in the literature.