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125
A Subspace, Interior, and Conjugate Gradient Method for LargeScale BoundConstrained Minimization Problems
 SIAM Journal on Scientific Computing
, 1999
"... A subspace adaptation of the ColemanLi trust region and interior method is proposed for solving largescale boundconstrained minimization problems. This method can be implemented with either sparse Cholesky factorization or conjugate gradient computation. Under reasonable conditions the convergenc ..."
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Cited by 35 (1 self)
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A subspace adaptation of the ColemanLi trust region and interior method is proposed for solving largescale boundconstrained minimization problems. This method can be implemented with either sparse Cholesky factorization or conjugate gradient computation. Under reasonable conditions the convergence properties of this subspace trust region method are as strong as those of its fullspace version.
Parallel Variable Distribution
 SIAM Journal on Optimization
, 1994
"... We present an approach for solving optimization problems in which the variables are distributed among p processors. Each processor has primary responsibility for updating its own block of variables in parallel while allowing the remaining variables to change in a restricted fashion (e. g. along a st ..."
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Cited by 34 (5 self)
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We present an approach for solving optimization problems in which the variables are distributed among p processors. Each processor has primary responsibility for updating its own block of variables in parallel while allowing the remaining variables to change in a restricted fashion (e. g. along a steepest descent, quasiNewton, or any arbitrary direction). This "forgetmenot" approach is a distinctive feature of our algorithm which has not been analyzed before. The parallelization step is followed by a fast synchronization step wherein the affine hull of the points computed by the parallel processors and the current point is searched for an optimal point. Convergence to a stationary point under continuous differentiability is established for the unconstrained case, as well as a linear convergence rate under the additional assumption of a Lipschitzian gradient and strong convexity. For problems constrained to lie in the Cartesian product of closed convex sets, convergence is establish...
On the convergence of a sequential quadratic programming method with an augmented Lagrangian line search function
 Math. Operstionsforschung und Statistik, Ser. Optimization
, 1983
"... Sequential quadratic programming (SQP) methods are widely used for solving practical optimization problems, especially in structural mechanics. The general structure of SQP methods is briefly introduced and it is shown how these methods can be adapted to distributed computing. However, SQP methods a ..."
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Cited by 32 (0 self)
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Sequential quadratic programming (SQP) methods are widely used for solving practical optimization problems, especially in structural mechanics. The general structure of SQP methods is briefly introduced and it is shown how these methods can be adapted to distributed computing. However, SQP methods are sensitive subject to errors in function and gradient evaluations. Typically they break down with an error message reporting that the line search cannot be terminated successfully. In these cases, a new nonmonotone line search is activated. In case of noisy function values, a drastic improvement of the performance is achieved compared to the version with monotone line search. Numerical results are presented for a set of more than 300 standard test examples.
Automatic preconditioning by limited memory QuasiNewton updating
 SIAM J. Optim
"... The paper proposes a preconditioner for the conjugate gradient method (CG) that is designed for solving systems of equations Ax = bi with di erent right hand side vectors, or for solving a sequence of slowly varying systems Akx = bk. The preconditioner has the form of a limited memory quasiNewton m ..."
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Cited by 31 (2 self)
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The paper proposes a preconditioner for the conjugate gradient method (CG) that is designed for solving systems of equations Ax = bi with di erent right hand side vectors, or for solving a sequence of slowly varying systems Akx = bk. The preconditioner has the form of a limited memory quasiNewton matrix and is generated using information from the CG iteration. The automatic preconditioner does not require explicit knowledge of the coe cient matrix A and is therefore suitable for problems where only products of A times avector can be computed. Numerical experiments indicate that the preconditioner has most to o er when these matrixvector products are expensive to compute, and when low accuracy in the solution is required. The e ectiveness of the preconditioner is tested within a Hessianfree Newton method for optimization, and by solving certain linear systems arising in nite element models.
A Repository of Convex Quadratic Programming Problems
 Optimization Methods and Software, 11 and 12:671–681
, 1997
"... The introdution of a standard set of linear programming problems, to be found in NETLIB/LP/DATA, had an important impact on measuring, comparing and reporting the performance of LP solvers. Until recently the efficiency of new algorithmic developments has been measured using this important reference ..."
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Cited by 27 (0 self)
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The introdution of a standard set of linear programming problems, to be found in NETLIB/LP/DATA, had an important impact on measuring, comparing and reporting the performance of LP solvers. Until recently the efficiency of new algorithmic developments has been measured using this important reference set. Presently, we are witnessing an ever growing interest in the area of quadratic programming. The research community is somewhat troubled by the lack of a standard format for defining a QP problem and also by the lack of a standard reference set of problems for purposes similar to that of LP. In the paper we propose a standard format and announce the availability of a test set of collected 138 QP problems.
Incomplete Cholesky Factorizations With Limited Memory
 SIAM J. SCI. COMPUT
, 1999
"... We propose an incomplete Cholesky factorization for the solution of largescale trust region subproblems and positive definite systems of linear equations. This factorization depends on a parameter p that specifies the amount of additional memory (in multiples of n, the dimension of the problem) tha ..."
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Cited by 27 (5 self)
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We propose an incomplete Cholesky factorization for the solution of largescale trust region subproblems and positive definite systems of linear equations. This factorization depends on a parameter p that specifies the amount of additional memory (in multiples of n, the dimension of the problem) that is available; there is no need to specify a drop tolerance. Our numerical results show that the number of conjugate gradient iterations and the computing time are reduced dramatically for small values of p. We also show that in contrast with drop tolerance strategies, the new approach is more stable in terms of number of iterations and memory requirements.
H.: A new conjugate gradient method with guaranteed descent and an efficient line search
 SIAM J. Optim
, 2005
"... Abstract. A new nonlinear conjugate gradient method and an associated implementation, based on an inexact line search, are proposed and analyzed. With exact line search, our method reduces to a nonlinear version of the Hestenes–Stiefel conjugate gradient scheme. For any (inexact) line search, our sc ..."
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Cited by 27 (6 self)
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Abstract. A new nonlinear conjugate gradient method and an associated implementation, based on an inexact line search, are proposed and analyzed. With exact line search, our method reduces to a nonlinear version of the Hestenes–Stiefel conjugate gradient scheme. For any (inexact) line search, our scheme satisfies the descent condition gT k dk ≤ − 7 8 ‖gk‖2. Moreover, a global convergence result is established when the line search fulfills the Wolfe conditions. A new line search scheme is developed that is efficient and highly accurate. Efficiency is achieved by exploiting properties of linear interpolants in a neighborhood of a local minimizer. High accuracy is achieved by using a convergence criterion, which we call the “approximate Wolfe ” conditions, obtained by replacing the sufficient decrease criterion in the Wolfe conditions with an approximation that can be evaluated with greater precision in a neighborhood of a local minimum than the usual sufficient decrease criterion. Numerical comparisons are given with both LBFGS and conjugate gradient methods using the unconstrained optimization problems in the CUTE library.
A new active set algorithm for box constrained Optimization
 SIAM Journal on Optimization
, 2006
"... Abstract. An active set algorithm (ASA) for box constrained optimization is developed. The algorithm consists of a nonmonotone gradient projection step, an unconstrained optimization step, and a set of rules for branching between the two steps. Global convergence to a stationary point is established ..."
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Cited by 26 (6 self)
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Abstract. An active set algorithm (ASA) for box constrained optimization is developed. The algorithm consists of a nonmonotone gradient projection step, an unconstrained optimization step, and a set of rules for branching between the two steps. Global convergence to a stationary point is established. For a nondegenerate stationary point, the algorithm eventually reduces to unconstrained optimization without restarts. Similarly, for a degenerate stationary point, where the strong secondorder sufficient optimality condition holds, the algorithm eventually reduces to unconstrained optimization without restarts. A specific implementation of the ASA is given which exploits the recently developed cyclic Barzilai–Borwein (CBB) algorithm for the gradient projection step and the recently developed conjugate gradient algorithm CG DESCENT for unconstrained optimization. Numerical experiments are presented using box constrained problems in the CUTEr and MINPACK2 test problem libraries. Key words. nonmonotone gradient projection, box constrained optimization, active set algorithm,
A survey of nonlinear conjugate gradient methods
 Pacific Journal of Optimization
, 2006
"... Abstract. This paper reviews the development of different versions of nonlinear conjugate gradient methods, with special attention given to global convergence properties. ..."
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Cited by 26 (3 self)
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Abstract. This paper reviews the development of different versions of nonlinear conjugate gradient methods, with special attention given to global convergence properties.
Parallel Gradient Distribution in Unconstrained Optimization
 SIAM Journal on Control and Optimization
, 1994
"... A parallel version is proposed for a fundamental theorem of serial unconstrained optimization. The parallel theorem allows each of k parallel processors to use simultaneously a different algorithm, such as a descent, Newton, quasiNewton or a conjugate gradient algorithm. Each processor can perform ..."
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Cited by 24 (7 self)
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A parallel version is proposed for a fundamental theorem of serial unconstrained optimization. The parallel theorem allows each of k parallel processors to use simultaneously a different algorithm, such as a descent, Newton, quasiNewton or a conjugate gradient algorithm. Each processor can perform one or many steps of a serial algorithm on a portion of the gradient of the objective function assigned to it, independently of the other processors. Eventually a synchronization step is performed which, for differentiable convex functions, consists of taking a strong convex combination of the k points found by the k processors. For nonconvex, as well as convex, differentiable functions, the best point found by the k processors is taken, or any better point. The fundamental result that we establish is that any accumulation point of the parallel algorithm is stationary for the nonconvex case, and is a global solution for the convex case. Computational testing on the Thinking Machines CM5 mul...