Results 71 to 80 of about 39,793 (262)

The Hybrid BFGS-CG Method in Solving Unconstrained Optimization Problems

Abstract and Applied Analysis, 2014
In solving large scale problems, the quasi-Newton method is known as the most efficient method in solving unconstrained optimization problems. Hence, a new hybrid method, known as the BFGS-CG method, has been created based on these properties, combining ...
Mohd Asrul Hery Ibrahim, Mustafa Mamat, Wah June Leong   +2 more
doaj   +1 more source

Identifying and attacking the saddle point problem in high-dimensional non-convex optimization [PDF]

, 2014
A central challenge to many fields of science and engineering involves minimizing non-convex error functions over continuous, high dimensional spaces.
Caglar Gulcehre, Kyunghyun Cho, Razvan Pascanu, Surya Ganguli, Universite ́ De Montréal, Yann N. Dauphin, Yoshua Bengio   +6 more
core  

Review and prospects of shear test of bolted rock joints

Deep Underground Science and Engineering, EarlyView.
The laboratory shear test equipment, test method, and numerical simulation of bolted rock joints were summarized. The shortcomings and limitations of the current research were analyzed, and the research prospects were proposed. Abstract Rock bolting is a critical approach in geotechnical engineering for supporting weak rocks.
Shulin Ren, Fan Yang, Manchao He, Yong Yuan, Zhigang Tao   +4 more
wiley   +1 more source

Migration speed, timing, and long‐term shifts in age structure in North American passerines during fall migration

Ecography, EarlyView.
Migration is challenging for birds, especially juveniles, who experience high mortality rates during migration. The challenge is exacerbated in the Anthropocene, contributing to widespread population declines. Conservation efforts focused on increasing juvenile survival could bolster population recovery.
Dylan M. Osterhaus, Martha J. Desmond, Timothy F. Wright   +2 more
wiley   +1 more source

A quasi-Newton approach to optimization problems with probability density constraints [PDF]

A quasi-Newton method is presented for minimizing a nonlinear function while constraining the variables to be nonnegative and sum to one. The nonnegativity constraints were eliminated by working with the squares of the variables and the resulting problem
Tapia, R. A., Vanrooy, D. L.
core   +1 more source

General Framework for Multi‐Degree‐of‐Freedom Stiffness Matrix Updating for Iterative Solution Algorithms in Hybrid Simulation

Earthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT Iterative solvers are advantageous for handling nonlinear structural analysis problems. The iterative solvers often require updating the stiffness matrix, which limits their application in static and pseudo‐dynamic hybrid simulations because: (1) updating the stiffness matrix of a system involving a physical specimen is challenging; (2 ...
Junyan Xiao, Oh‐Sung Kwon, Evan Bentz
wiley   +1 more source

Machine Learning in Quasi-Newton Methods

Axioms
In this article, we consider the correction of metric matrices in quasi-Newton methods (QNM) from the perspective of machine learning theory. Based on training information for estimating the matrix of the second derivatives of a function, we formulate a ...
Vladimir Krutikov, Elena Tovbis, Predrag Stanimirović, Lev Kazakovtsev, Darjan Karabašević   +4 more
doaj   +1 more source

Quasi-Newton Based Preconditioning and Damped Quasi-Newton Schemes for Nonlinear Conjugate Gradient Methods [PDF]

, 2018
In this paper, we deal with matrix-free preconditioners for nonlinear conjugate gradient (NCG) methods. In particular, we review proposals based on quasi-Newton updates, and either satisfying the secant equation or a secant-like equation at some of the previous iterates.
Mehiddin Al-Baali, Andrea Caliciotti, Giovanni Fasano, Massimo Roma   +3 more
openaire   +1 more source

Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver

International Journal for Numerical Methods in Fluids, EarlyView.
A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley   +1 more source

A numerical solution of parabolic quasi-variational inequality nonlinear using Newton-multigrid method [PDF]

Iranian Journal of Numerical Analysis and Optimization
In this article, we apply three numerical methods to study the L∞-convergence of the Newton-multigrid method for parabolic quasi-variational inequalities with a nonlinear right-hand side.
M. Bahi, M. Beggas, N. Nesba, A. Imtiaz
doaj   +1 more source