Namur Institute for Complex Systems

  • 5000

    Belgium

Research Output 1977 2020

Filter
Working paper
20 Downloads (Pure)
File
12 Downloads (Pure)

Adaptive Observations And Multilevel Optimization In Data Assimilation

Gratton, S., Rincon-Camacho, M. & Toint, P., 2013, Namur: Namur center for complex systems, 18 p.

Research output: Working paper

File
data assimilation
decomposition
wave equation
weather
prediction
4 Downloads (Pure)
File
Rain
Weather forecasting
Costs
63 Downloads (Pure)
File
Unconstrained Minimization
Steepest Descent Method
Evaluation Function
Terminate
Iterate
117 Downloads (Pure)
File
Interior Point
Nonlinear Optimization
Matrix Derivative
Merit Function
Quadratic Optimization
1 Downloads (Pure)

A note on solving nonlinear optimization problems in variable precision

Gratton, S. & Toint, P., 11 Dec 2018, Arxiv, 11 p.

Research output: Working paper

File
Function evaluation
Energy dissipation
Costs
Experiments
8 Downloads (Pure)
File
Forced oscillation
Integrable Systems
Numerical Algorithms
Search Algorithm
Initial conditions
4 Downloads (Pure)

Exploiting variable precision in GMRES

Gratton, S., Simon, E., Titley-Peloquin, D. & Toint, P., Jul 2019, 19 p.

Research output: Working paper

File
GMRES
Digital arithmetic
Arnoldi
Iterative Solver
Floating-point Arithmetic

Global and local information in structured derivative free optimization with BFO

Porcelli, M. & Toint, P., 15 Jan 2020, Arxiv, 27 p.

Research output: Working paper

File
Derivatives
Constrained optimization
Interpolation
25 Downloads (Pure)

Improved worst-case evaluation complexity for potentially rank-deficient nonlinear least-Euclidean-norm problems using higher-order regularized models

Cartis, C., Gould, N. I. M. & Toint, P., 18 Nov 2015, 18 p. (naXys technical report).

Research output: Working paper

File
Euclidean norm
Local Minimizer
Vector-valued Functions
Taylor series
Criticality

Inflation forecasts in the euro area: Are domestic and global factors useful in forecasting the mean and the distribution of euro area inflation?

Bereau, S., Faubert, V. & Schmidt, K., 2018, (Banque de France Working Papers series; no. 663).

Research output: Working paper

11 Downloads (Pure)

Minimizing convex quadratics with variable precision Krylov methods

Gratton, S., Simon, E. & Toint, P., 2018, (Submitted) Arxiv, 26 p.

Research output: Working paper

File
Krylov Methods
Quadratic Optimization
Cross product
Matrix Product
Conjugate Gradient
5 Downloads (Pure)

On the use of the saddle formulation in weakly-constrained 4D-VAR data assimilation

Gratton, S., Gürol, S., Simon, E. & Toint, P., 20 Sep 2017, (Submitted) Arxiv.

Research output: Working paper

File
Data Assimilation
Saddle
Parallel processing systems
data assimilation
parallel computing
12 Downloads (Pure)

Quantifying the degree of average contraction of Collatz orbits

Carletti, T. & Fanelli, D., 21 Dec 2016, (Submitted) Namur center for complex systems, 18 p.

Research output: Working paper

File
Contraction
Orbit
Modulo
Integer
Iterate

Sovereign bond spreads: the role of debt accumulation

Gnabo, J-Y. & Bernal Diaz, O., 2012, (Unpublished).

Research output: Working paper

Yield spread
Asset prices
Surprise
Credit rating
Price dynamics
27 Downloads (Pure)

Worst-case evaluation complexity and optimality of second-order methods for nonconvex smooth optimization

Cartis, C., Gould, N. I. M. & Toint, P., 22 Sep 2017, Arxiv, 35 p.

Research output: Working paper

File
Newton-Raphson method
Optimality
Optimization
Function evaluation
Evaluation
10 Downloads (Pure)

Worst-case evaluation complexity for unconstrained nonlinear optimization using high-order regularized models

Birgin, E., Gardenghi, J., Martinez, J-M., Santos, S. A. & Toint, P., Jun 2015, 2015: Namur center for complex systems, 8 p. (naXys Technical Reports; vol. 05-2015).

Research output: Working paper

File
Unconstrained Optimization
Nonlinear Optimization
Higher Order
Derivatives
Derivative