Results 121 to 130 of about 463,836 (293)

A Quasi-Newton Method with No Derivatives [PDF]

Mathematics of Computation, 1972
The Davidon formula and others of the “quasi-Newton” class, which are used in the unconstrained minimization of a function f f , provide a (generally) convergent sequence of approximations to the Hessian of f f . These formulas, however, require the independent calculation of the gradient of f f .
openaire   +1 more source

Bending Analysis of Thickness‐ and Shear‐Deformable Materially Imperfect Composite Shells With von Kármán‐Type Geometric Nonlinearities

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT Geometrically nonlinear static analysis of materially imperfect composite doubly curved shells is investigated via the generalised differential quadrature method. The effects of both shear and thickness deformation are considered through a thickness‐ and shear‐deformable third‐order theory formulated in curvilinear coordinates, while the ...
Behrouz Karami, Mergen H. Ghayesh, Shahid Hussain, Marco Amabili   +3 more
wiley   +1 more source

Numerical Modeling of Geological Fault Reactivation Using Sequential Coupling Strategies

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT The interaction between fluid flow and mechanical deformation in fault zones can lead to processes of fault reactivation, triggering potential geomechanical problems such as seismicity, well collapse, fluid migration to shallower layers, and aggravated surface subsidence.
Julio Rueda, Cristian Mejia, Roberto Quevedo, Deane Roehl   +3 more
wiley   +1 more source

A pilot variational coupled reanalysis based on the CESAM climate model

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Variational data assimilation of in‐situ and satellite ocean data and reanalysis atmospheric data into an intermediate complexity Earth system model is possible by adjusting the surface fluxes and internal model parameters. This pilot application requires nearly complete information on the atmospheric state for synchronization.
Armin Köhl, Iuliia Polkova, Guokun Lyu, Frank Lunkeit, Abhirup Banerjee, Silke Schubert, Detlef Stammer   +6 more
wiley   +1 more source

Computing the Projection on the Intersection of Linear Equality and Cardinality Constraints

IEEE Access
In this paper, we introduce a novel approach to solve the vector projection problem under linear equality and cardinality constraints, termed the Quasi-Newton Lagrangian method. This approach employs a Lagrangian transformation to address linear equality
Xiao-Jing Wang, Zhen-Sheng Yu
doaj   +1 more source

A new smoother method for treating different timescales in variational data assimilation for coupled systems

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We propose a new method for treating different timescales in coupled variational data assimilation for atmosphere–ocean models. The approach involves a series of short‐window coupled assimilations (red arrows in the schematic) followed by a long‐window correction to the ocean fields (blue arrow).
Amos S. Lawless, Nancy K. Nichols, Tsz Yan Leung, Shaerdan Shataer   +3 more
wiley   +1 more source

LEARNING ALGORITHM EFFECT ON MULTILAYER FEED FORWARD ARTIFICIAL NEURAL NETWORK PERFORMANCE IN IMAGE CODING [PDF]

Journal of Engineering Science and Technology, 2007
One of the essential factors that affect the performance of Artificial Neural Networks is the learning algorithm. The performance of Multilayer Feed Forward Artificial Neural Network performance in image compression using different learning algorithms is
OMER MAHMOUD, FARHAT ANWAR, MOMOH JIMOH E. SALAMI   +2 more
doaj  

Sonified Signals From a Compact FT‐ICR Instrument: A Feasibility Study. I—Data Mapping to an Equal‐Tempered Chromatic Scale

Rapid Communications in Mass Spectrometry, EarlyView.
ABSTRACT Rationale Ions trapped within a Penning cell (ICR) travel periodic orbits whose frequencies are dependent on their mass‐to‐charge ratio and the value of the magnetic field passing through the trap. Fourier transformation (FT‐ICR) decomposes the signal induced in the detection circuit by the rotation of the ions in the cell after the ...
Patrick Arpino, Michel Heninger
wiley   +1 more source

ANÁLISIS DE LA FRONTERA DE CONVERGENCIA EN MÉTODOS CUASI-NEWTON CON MATRICES DISPERSAS Y SU APLICACIÓN A LA GEOMECÁNICA DE VOLADURAS

Avances en Ciencias e Ingeniería
We delimit the convergence frontier of sparse–matrix quasi-Newton algorithms for rock-blasting simulations. Lip- schitz/Hölder bounds yield Kantorovich radii that mark when the secant matrix preserves contraction.
Fabian León, Luis Rojas, Cristian Gonzalez, Beatriz Hernández, José García   +4 more
doaj   +1 more source

Action constrained quasi-Newton methods

, 2014
At the heart of Newton based optimization methods is a sequence of symmetric linear systems. Each consecutive system in this sequence is similar to the next, so solving them separately is a waste of computational effort. Here we describe automatic preconditioning techniques for iterative methods for solving such sequences of systems by maintaining an ...
Gower, Robert Mansel, Gondzio, Jacek
openaire   +2 more sources