Accuracy of policy function approximations for strongly concave recursive problems

2018 ◽  
Vol 15 (3) ◽  
pp. 249-267
Author(s):  
Wilfredo L. Maldonado ◽  
Osvaldo Candido ◽  
Luis Felipe V. N. Pereira
Keyword(s):  
Function Approximations ◽  
Policy Function

Acoustic Green's Function Approximations

1998 ◽  
Vol 06 (04) ◽  
pp. 435-452 ◽  
Author(s):  
Robert P. Gilbert ◽  
Zhongyan Lin ◽  
Klaus Hackl
Keyword(s):  
Inverse Problem ◽  
Normal Mode ◽  
Eigenvalue Problems ◽  
Normal Modes ◽  
Modal Parameters ◽  
Mindlin Plate ◽  
Ocean Bottom ◽  
Hankel Transformation ◽  
Poroelastic Materials ◽  
Function Approximations

Normal-mode expansions for Green's functions are derived for ocean–bottom systems. The bottom is modeled by Kirchhoff and Reissner–Mindlin plate theories for elastic and poroelastic materials. The resulting eigenvalue problems for the modal parameters are investigated. Normal modes are calculated by Hankel transformation of the underlying equations. Finally, the relation to the inverse problem is outlined.

MONETARY POLICY SWITCHING IN THE EURO AREA AND MULTIPLE STEADY STATES: AN EMPIRICAL INVESTIGATION

2016 ◽  
Vol 21 (5) ◽  
pp. 1175-1188 ◽  
Author(s):  
Gilles Dufrénot ◽  
Guillaume A. Khayat
Keyword(s):  
Steady State ◽  
Euro Area ◽  
European Central Bank ◽  
Empirical Investigation ◽  
Standard Assumption ◽  
Demand Shock ◽  
Liquidity Trap ◽  
European Central ◽  
Parameter Values ◽  
Policy Function

This paper investigates, in the case of the euro area, the standard assumption that the liquidity trap steady state, which arises from the existence of the zero lower bound on the nominal interest rate, is locally unstable. We show that the policy function of the European Central Bank (ECB) is described by a nonlinear Taylor rule. Then, using our estimations, we show that around the liquidity trap steady state the equilibrium is locally determinate for most plausible parameter values. Finally, we find that an inflation shock is more efficient than a demand shock to escape the liquidity trap steady state.

P -Function Approximations for Jet Momentum Flux

1972 ◽  
Vol 98 (4) ◽  
pp. 1011-1016
Author(s):  
W. Hall C. Maxwell ◽  
Kuo-Cheng Chang
Keyword(s):  
Momentum Flux ◽  
Function Approximations

The solution of theoretical seismic problems by best rational function approximations for Laplace transform inversion

1975 ◽  
Vol 65 (4) ◽  
pp. 927-935
Author(s):  
I. M. Longman ◽  
T. Beer
Keyword(s):  
Laplace Transform ◽  
Rational Function ◽  
High Accuracy ◽  
Time Variable ◽  
Inversion Method ◽  
The Laplace Transform ◽  
Previously Treated ◽  
The Mean ◽  
Function Approximations ◽  
Laplace Transform Inversion

Abstract In a recent paper, the first author has developed a method of computation of “best” rational function approximations ḡn(p) to a given function f̄(p) of the Laplace transform operator p. These approximations are best in the sense that analytic inversion of ḡn(p) gives a function gn(t) of the time variable t, which approximates the (generally unknown) inverse f(t) of f̄(p in a minimum least-squares manner. Only f̄(p) but not f(t) is required to be known in order to carry out this process. n is the “order” of the approximation, and it can be shown that as n tends to infinity gn(t) tends to f(t) in the mean. Under suitable conditions on f(t) the convergence is extremely rapid, and quite low values of n (four or five, say) are sufficient to give high accuracy for all t ≧ 0. For seismological applications, we use geometrical optics to subtract out of f(t) its discontinuities, and bring it to a form in which the above inversion method is very rapidly convergent. This modification is of course carried out (suitably transformed) on f̄(p), and the discontinuities are restored to f(t) after the inversion. An application is given to an example previously treated by the first author by a different method, and it is a certain vindication of the present method that an error in the previously given solution is brought to light. The paper also presents a new analytical method for handling the Bessel function integrals that occur in theoretical seismic problems related to layered media.

scholarly journals Global Optimization Method to Multiple Local Optimals with the Surface Approximation Methodology and Its Application for Industry Problems

2021 ◽  
Author(s):  
Ichiro Hagiwara
Keyword(s):  
Neural Network ◽  
Region Of Interest ◽  
Optimization Method ◽  
Mapping Method ◽  
Vehicle Performance ◽  
Vehicle Component ◽  
Generalized Inverse Matrix ◽  
Global Optimal ◽  
Function Approximations ◽  
Vehicle Crashworthiness

Although generally speaking, a great number of functional evaluations may be required until convergence, it can be solved by using neural network effectively. Here, techniques to search the region of interest containing the global optimal design selected by random seeds is investigated. Also techniques for finding more accurate approximation using Holographic Neural Network (HNN) improved by using penalty function for generalized inverse matrix is investigated. Furthermore, the mapping method of extrapolation is proposed to make the technique available to general application in structural optimization. Application examples show that HNN may be expected as potential activate and feasible surface functions in response surface methodology than the polynomials in function approximations. Finally, the real design examples of a vehicle performance such as idling vibration, booming noise, vehicle component crash worthiness and combination problem between vehicle crashworthiness and restraint device performance at the head-on collision are used to show the effectiveness of the proposed method.

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