Grundlagen der Matrixrechnung -- Innerbetriebliche simultane Leistungsverrechnung -- Weiterführende Matrixrechnung -- Innerbetriebliche Materialverflechtung -- Leontief-Modell -- Allgemeine lineare Gleichungssysteme -- Vektorraumtheorie -- Lineare Optimierung.

We consider the estimation of integrated covariance (ICV) matrices of high dimensional diffusion processes based on high frequency observations. We start by studying the most commonly used estimator, the realized covariance (RCV) matrix. We show that in the high dimensional case when the...

We have presented two simple methods to produce a feasible (i.e. real, symmetric, and positivesemidefinite) correlation matrix when the econometric one is either noisy, unavailable, or inappropriate. The first method is to the knowledge of the authors more general than any of the approaches...

The Markowitz mean-variance framework is the foundation of modern portfolio theory. One problem with this approach, however, is how sample covariance matrices tend to underestimate risk. Since the biases of optimized portfolios are closely related to eigenfactor portfolios, we present a...

Correlations play an important role in the construction of investment portfolios. In this research note, we explain why the manipulation of a valid correlation matrix is challenging. We also propose three methods to perform the following tasks: 1) Increase all correlations such that they...