Results 121 to 130 of about 103,871 (266)
On the Keldys-Fichera boundary-value problem for degenerate quasilinear elliptic equations
We prove existence and uniqueness theorems for the Keldys-Fichera boundary-value problem using pseudo-monotone operators. The equation studied here is quasilinear, elliptic, and its set of degenerate points may be of non-zero measure.
Zu-Chi Chen, Benjin Xuan
doaj
Uncertainty Calibration in Molecular Machine Learning: Comparing Evidential and Ensemble Approaches
Raw uncertainty estimates from deep evidential regression and deep ensembles are systematically miscalibrated. Post hoc calibration aligns predicted uncertainty with true errors, improving reliability and enabling efficient active learning and reducing computational cost while preserving predictive accuracy.
Bidhan Chandra Garain +3 more
wiley +1 more source
Unique solvability for a second order nonlinear system via two global inversion theorems
In this paper we use two global inversion theorems to establish the existence and uniqueness for a nonlinear second order homogeneous Dirichlet system.
Robert Dalmasso
doaj
An observation‐driven state‐space model for claims size modelling
Abstract State‐space models are popular in econometrics. Recently, these models have gained some popularity in the actuarial literature. The best known state‐space models are of the Kalman‐filter type. These are called parameter‐driven because the observations do not impact the state‐space dynamics.
Jae Youn Ahn +2 more
wiley +1 more source
Optimal dividends for a NatCat insurer in the presence of a climate tipping point
Abstract We study optimal dividend strategies for an insurance company facing natural catastrophe claims, anticipating the arrival of a climate tipping point after which the claim intensity and/or the claim size distribution of the underlying risks deteriorates irreversibly.
Hansjörg Albrecher +2 more
wiley +1 more source
T‐calibration in semi‐parametric models
Abstract This article relates the calibration of models to the consistent loss functions for the target functional of the model. Correctly specified models are calibrated. Conversely, we demonstrate that if there is a parameter value that is optimal under all consistent loss functions, then a model is calibrated.
Anja Mühlemann, Johanna Ziegel
wiley +1 more source
Asymptotic independence in more than two dimensions and its implications on risk management
Abstract In extreme value theory, the presence of asymptotic independence signifies that joint extreme events across multiple variables are unlikely. Although well understood in a bivariate context, the concept remains relatively unexplored when addressing the nuances of simultaneous occurrence of extremes in higher dimensions.
Bikramjit Das, Vicky Fasen‐Hartmann
wiley +1 more source
Abstract We analyze the effect of regulatory capital constraints on financial stability in a large homogeneous banking system using a mean‐field game (MFG) model. Each bank holds cash and a tradable risky asset. Banks choose absolutely continuous trading rates in order to maximize expected terminal equity, with trades subject to transaction costs ...
Rüdiger Frey, Theresa Traxler
wiley +1 more source
A Markov approach to credit rating migration conditional on economic states
Abstract We develop a model for credit rating migration that accounts for the impact of economic state fluctuations on default probabilities. The joint process for the economic state and the rating is modelled as a time‐homogeneous Markov chain. While the rating process itself possesses the Markov property only under restrictive conditions, methods ...
Michael Kalkbrener, Natalie Packham
wiley +1 more source
Existence and uniqueness theorems for Riemann problems [PDF]
openaire +1 more source

