The Experts below are selected from a list of 7179 Experts worldwide ranked by ideXlab platform
Boris Vexler - One of the best experts on this subject based on the ideXlab platform.
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a Priori Error estimates for space time finite element discretization of parabolic optimal control problems
Siam Journal on Control and Optimization, 2019Co-Authors: Dominik Meidner, Boris VexlerAbstract:In this article we summarize recent results on a Priori Error estimates for space-time finite element discretizations of linear-quadratic parabolic optimal control problems. We consider the following three cases: problems without inequality constraints, problems with pointwise control constraints, and problems with state constraints pointwise in time. For all cases, Error estimates with respect to the temporal and to the spatial discretization parameters are derived. The results are illustrated by numerical examples.
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A Priori Error Estimates for Space-Time Finite Element Discretization of Parabolic Time-Optimal Control Problems
arXiv: Optimization and Control, 2018Co-Authors: Lucas Bonifacius, Konstantin Pieper, Boris VexlerAbstract:Space-time finite element discretizations of time-optimal control problems governed by linear parabolic PDEs and subject to pointwise control constraints are considered. Optimal a Priori Error estimates are obtained for the control variable based on a second order sufficient optimality condition.
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optimal a Priori Error estimates of parabolic optimal control problems with pointwise control
SIAM Journal on Numerical Analysis, 2013Co-Authors: Dmitriy Leykekhman, Boris VexlerAbstract:In this paper we consider a parabolic optimal control problem with a pointwise (Dirac type) control in space, but variable in time, in two space dimensions. To approximate the problem we use the standard continuous piecewise linear approximation in space and the piecewise constant discontinuous Galerkin method in time. Despite low regularity of the state equation, we show almost optimal $h^2+k$ convergence rate for the control in $L^2$ norm. This result improves almost twice the previously known estimate in [W. Gong, M. Hinze, and Z. Zhou, A Priori Error Analysis for Finite Element Approximation of Parabolic Optimal Control Problems with Pointwise Control, Tech. report, 2011-07, Hamburger Beitrage zur Angewandten Mathematik, Hamburg, Germany, 2011].
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a Priori Error analysis for discretization of sparse elliptic optimal control problems in measure space
Siam Journal on Control and Optimization, 2013Co-Authors: Konstantin Pieper, Boris VexlerAbstract:In this paper an optimal control problem is considered, where the control variable lies in a measure space and the state variable fulfills an elliptic equation. This formulation leads to a sparse structure of the optimal control. In this setting we prove a new regularity result for the optimal state and the optimal control. Moreover, a finite element discretization based on [E. Casas, C. Clason, and K. Kunisch, SIAM J. Control Optim., 50 (2012), pp. 1735--1752] is discussed and a Priori Error estimates are derived, which significantly improve the estimates from that paper. Numerical examples for problems in two and three space dimensions illustrate our results.
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a Priori Error estimates for elliptic optimal control problems with a bilinear state equation
Journal of Computational and Applied Mathematics, 2009Co-Authors: Axel Kroner, Boris VexlerAbstract:In this paper a Priori Error analysis for the finite element discretization of an optimal control problem governed by an elliptic state equation is considered. The control variable enters the state equation as a coefficient and is subject to pointwise inequality constraints. We derive a Priori Error estimates for the discretization Error in the control variable and confirm our theoretical results by numerical examples.
Anthony Fagan - One of the best experts on this subject based on the ideXlab platform.
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Pipelined implementations of the A Priori Error-feedback LSL algorithm using logarithmic arithmetic
ICASSP IEEE International Conference on Acoustics Speech and Signal Processing - Proceedings, 2002Co-Authors: Felix Albu, Jiri Kadlec, Nick Coleman, Anthony FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinability are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
Felix Albu - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - Pipelined implementations of the a Priori Error-Feedback LSL algorithm using logarithmic arithmetic
IEEE International Conference on Acoustics Speech and Signal Processing, 2002Co-Authors: Felix Albu, Nick Coleman, Jiri Kadlec, Anthony D. FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinabilty are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
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Pipelined implementations of the A Priori Error-feedback LSL algorithm using logarithmic arithmetic
ICASSP IEEE International Conference on Acoustics Speech and Signal Processing - Proceedings, 2002Co-Authors: Felix Albu, Jiri Kadlec, Nick Coleman, Anthony FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinability are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
Nick Coleman - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - Pipelined implementations of the a Priori Error-Feedback LSL algorithm using logarithmic arithmetic
IEEE International Conference on Acoustics Speech and Signal Processing, 2002Co-Authors: Felix Albu, Nick Coleman, Jiri Kadlec, Anthony D. FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinabilty are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
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Pipelined implementations of the A Priori Error-feedback LSL algorithm using logarithmic arithmetic
ICASSP IEEE International Conference on Acoustics Speech and Signal Processing - Proceedings, 2002Co-Authors: Felix Albu, Jiri Kadlec, Nick Coleman, Anthony FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinability are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
Jiri Kadlec - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - Pipelined implementations of the a Priori Error-Feedback LSL algorithm using logarithmic arithmetic
IEEE International Conference on Acoustics Speech and Signal Processing, 2002Co-Authors: Felix Albu, Nick Coleman, Jiri Kadlec, Anthony D. FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinabilty are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.
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Pipelined implementations of the A Priori Error-feedback LSL algorithm using logarithmic arithmetic
ICASSP IEEE International Conference on Acoustics Speech and Signal Processing - Proceedings, 2002Co-Authors: Felix Albu, Jiri Kadlec, Nick Coleman, Anthony FaganAbstract:In this paper we present several implementations of the Modified A Priori Error-Feedback LSL (EF-LSL) algorithm [1] on the VIRTEX FPGA. Its computational parallelism and pipelinability are important advantages. Internally, the computations are based on the logarithmic number system. We compare 32-bit (SINGLE-ALU or DUAL-ALU version) and 20-bit (QUADRI-ALU versions). We show that the LNS implementation can outperform the standard DSP solutions based on 32-bit floating-point processors.