For the large sparse block two-by-two real nonsingular matrices, we establish a general framework of practical and efficient structured preconditioners through matrix transformation and matrix ...

A block-structured model for the reconstruction of directed and weighted financial networks spanning multiple countries is developed. In a first step, link probability matrixes are derived via a ...

May’s celebrated theoretical work of the 70’s contradicted the established paradigm by demonstrating that complexity leads to instability in biological systems. Here May’s random-matrix modelling ...

Random sampling from a multivariate normal distribution is essential for Monte Carlo simulations in many credit risk models. For a portfolio of N obligors, standard methods usually require O(N2) ...

Journal of Applied Probability, Vol. 27, No. 3 (Sep., 1990), pp. 557-576 (20 pages) In this paper we consider two-dimensional Markov chains with the property that, except for some boundary conditions, ...