The Experts below are selected from a list of 97599 Experts worldwide ranked by ideXlab platform

W Nazarewicz - One of the best experts on this subject based on the ideXlab platform.

  • nuclear energy density Optimization large deformations
    Physical Review C, 2012
    Co-Authors: M Kortelainen, W Nazarewicz, J Sarich, N Schunck, J Mcdonnell, P G Reinhard, M Stoitsov, Stefan M Wild
    Abstract:

    A new Skyrme-like energy density suitable for studies of strongly elongated nuclei has been determined in the framework of the Hartree-Fock-Bogoliubov theory using the recently developed model-based, Derivative-Free Optimization algorithm POUNDerS. A sensitivity analysis at the optimal solution has revealed the importance of states at large deformations in driving the parameterization of the functional. The good agreement with experimental data on masses and separation energies, achieved with the previous parameterization UNEDF0, is largely preserved. In addition, the new energy density UNEDF1 gives a much improved description of the fission barriers in ^{240}Pu and neighboring nuclei.

  • nuclear energy density Optimization
    Physical Review C, 2010
    Co-Authors: M Kortelainen, T Lesinski, Jorge J More, W Nazarewicz, J Sarich, N Schunck
    Abstract:

    We carry out state-of-the-art Optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, Derivative-Free Optimization algorithm used in this work ��

M Kortelainen - One of the best experts on this subject based on the ideXlab platform.

  • nuclear energy density Optimization large deformations
    Physical Review C, 2012
    Co-Authors: M Kortelainen, W Nazarewicz, J Sarich, N Schunck, J Mcdonnell, P G Reinhard, M Stoitsov, Stefan M Wild
    Abstract:

    A new Skyrme-like energy density suitable for studies of strongly elongated nuclei has been determined in the framework of the Hartree-Fock-Bogoliubov theory using the recently developed model-based, Derivative-Free Optimization algorithm POUNDerS. A sensitivity analysis at the optimal solution has revealed the importance of states at large deformations in driving the parameterization of the functional. The good agreement with experimental data on masses and separation energies, achieved with the previous parameterization UNEDF0, is largely preserved. In addition, the new energy density UNEDF1 gives a much improved description of the fission barriers in ^{240}Pu and neighboring nuclei.

  • nuclear energy density Optimization
    Physical Review C, 2010
    Co-Authors: M Kortelainen, T Lesinski, Jorge J More, W Nazarewicz, J Sarich, N Schunck
    Abstract:

    We carry out state-of-the-art Optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, Derivative-Free Optimization algorithm used in this work ��

N Schunck - One of the best experts on this subject based on the ideXlab platform.

  • nuclear energy density Optimization large deformations
    Physical Review C, 2012
    Co-Authors: M Kortelainen, W Nazarewicz, J Sarich, N Schunck, J Mcdonnell, P G Reinhard, M Stoitsov, Stefan M Wild
    Abstract:

    A new Skyrme-like energy density suitable for studies of strongly elongated nuclei has been determined in the framework of the Hartree-Fock-Bogoliubov theory using the recently developed model-based, Derivative-Free Optimization algorithm POUNDerS. A sensitivity analysis at the optimal solution has revealed the importance of states at large deformations in driving the parameterization of the functional. The good agreement with experimental data on masses and separation energies, achieved with the previous parameterization UNEDF0, is largely preserved. In addition, the new energy density UNEDF1 gives a much improved description of the fission barriers in ^{240}Pu and neighboring nuclei.

  • nuclear energy density Optimization
    Physical Review C, 2010
    Co-Authors: M Kortelainen, T Lesinski, Jorge J More, W Nazarewicz, J Sarich, N Schunck
    Abstract:

    We carry out state-of-the-art Optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, Derivative-Free Optimization algorithm used in this work ��

Stefan M Wild - One of the best experts on this subject based on the ideXlab platform.

  • global convergence of radial basis function trust region algorithms for derivative free Optimization
    Siam Review, 2013
    Co-Authors: Stefan M Wild, Christine A Shoemaker
    Abstract:

    We analyze globally convergent, Derivative-Free trust-region algorithms relying on radial basis function interpolation models. Our results extend the recent work of Conn, Scheinberg, and Vicente [SIAM J. Optim., 20 (2009), pp. 387--415] to fully linear models that have a nonlinear term. We characterize the types of radial basis functions that fit in our analysis and thus show global convergence to first-order critical points for the ORBIT algorithm of Wild, Regis, and Shoemaker [SIAM J. Sci. Comput., 30 (2008), pp. 3197--3219]. Using ORBIT, we present numerical results for different types of radial basis functions on a series of test problems. We also demonstrate the use of ORBIT in finding local minima on a computationally expensive environmental engineering problem involving remediation of contaminated groundwater.

  • nuclear energy density Optimization large deformations
    Physical Review C, 2012
    Co-Authors: M Kortelainen, W Nazarewicz, J Sarich, N Schunck, J Mcdonnell, P G Reinhard, M Stoitsov, Stefan M Wild
    Abstract:

    A new Skyrme-like energy density suitable for studies of strongly elongated nuclei has been determined in the framework of the Hartree-Fock-Bogoliubov theory using the recently developed model-based, Derivative-Free Optimization algorithm POUNDerS. A sensitivity analysis at the optimal solution has revealed the importance of states at large deformations in driving the parameterization of the functional. The good agreement with experimental data on masses and separation energies, achieved with the previous parameterization UNEDF0, is largely preserved. In addition, the new energy density UNEDF1 gives a much improved description of the fission barriers in ^{240}Pu and neighboring nuclei.

  • benchmarking derivative free Optimization algorithms
    Siam Journal on Optimization, 2009
    Co-Authors: Jorge J More, Stefan M Wild
    Abstract:

    We propose data profiles as a tool for analyzing the performance of Derivative-Free Optimization solvers when there are constraints on the computational budget. We use performance and data profiles, together with a convergence test that measures the decrease in function value, to analyze the performance of three solvers on sets of smooth, noisy, and piecewise-smooth problems. Our results provide estimates for the performance difference between these solvers, and show that on these problems, the model-based solver tested performs better than the two direct search solvers tested.

Miguel Angel Gutierrezlimon - One of the best experts on this subject based on the ideXlab platform.

  • dynamic Optimization of a cryogenic air separation unit using a derivative free Optimization approach
    Computers & Chemical Engineering, 2018
    Co-Authors: Israel Negrellosortiz, Antonio Florestlacuahuac, Miguel Angel Gutierrezlimon
    Abstract:

    Abstract Optimal dynamic product transition is a challenging and important issue in manufacturing plants. When a reliable dynamic model is available, gradient-based Optimization algorithms can be used to achieve this aim. However, in some cases a first principles dynamic model may not be available. In this work, we will assume that only input-output information from a dynamic model embedded in a dynamic process simulator is available for optimal product transitions between products. We present a Derivative-Free Optimization trust region approach to deal with the product dynamic Optimization problem of an air separation unit used in several processing plants to obtain pure oxygen. High-purity oxygen is required in intensive energy applications such as steel plants and in combustion processes. A closed-loop model predictive control strategy is used where the system to be optimized is embedded in the ASPEN Dynamics simulation environment. The results demonstrate that black-box dynamic models can be dynamically optimized when model of the dynamic model and/or its gradient information are not available. We have successfully applied the non-linear model predictive control and derivate-free approach to several oxygen composition and productivity transition issues.

  • dynamic Optimization of a cryogenic air separation unit using a derivative free Optimization approach
    Computers & Chemical Engineering, 2018
    Co-Authors: Israel Negrellosortiz, Antonio Florestlacuahuac, Miguel Angel Gutierrezlimon
    Abstract:

    Abstract Optimal dynamic product transition is a challenging and important issue in manufacturing plants. When a reliable dynamic model is available, gradient-based Optimization algorithms can be used to achieve this aim. However, in some cases a first principles dynamic model may not be available. In this work, we will assume that only input-output information from a dynamic model embedded in a dynamic process simulator is available for optimal product transitions between products. We present a Derivative-Free Optimization trust region approach to deal with the product dynamic Optimization problem of an air separation unit used in several processing plants to obtain pure oxygen. High-purity oxygen is required in intensive energy applications such as steel plants and in combustion processes. A closed-loop model predictive control strategy is used where the system to be optimized is embedded in the ASPEN Dynamics simulation environment. The results demonstrate that black-box dynamic models can be dynamically optimized when model of the dynamic model and/or its gradient information are not available. We have successfully applied the non-linear model predictive control and derivate-free approach to several oxygen composition and productivity transition issues.