For a continuous multi-objective optimization problem, it is usually not a practical approach to compute all its nondominated points because there are infinitely many of them. For this reason, a typical approach is to compute an approximation of the nondominated set. A common technique for this...

In a single-objective setting, nonconvex quadratic problems can equivalently be reformulated as convex problems over the cone of completely positive matrices. In small dimensions this cone equals the cone of matrices which are entrywise nonnegative and positive semidefinite, so the convex...

The problem of minimizing the difference of two convex functions is called polyhedral d.c. optimization problem if at least one of the two component functions is polyhedral. We characterize the existence of global optimal solutions of polyhedral d.c. optimization problems. This result is used to...

It is a challenging task to identify the objectives on which a certain decision was based, in particular if several, potentially conflicting criteria are equally important and a continuous set of optimal compromise decisions exists. This task can be understood as the inverse problem of...

An important aspect of optimization algorithms, for instance evolutionary algorithms, are termination criteria that measure the proximity of the found solution to the optimal solution set. A frequently used approach is the numerical verification of necessary optimality conditions such as the...

This paper tests the Purchasing Power Parity Theory of Exchange Rates dealing with Argentinean data for the period 1900-2006. This is equivalent to testing if the Real Exchange Rate is a stationary variable or if its components (the nominal exchange rate and the relative prices) are...

The European Union is currently experiencing its largest influx of asylum seekers in years. Yet the distribution of these refugees across the member states is highly uneven: Large countries such as the United Kingdom, France, Italy, and Spain, as well as the Eastern European countries (apart...

In die Europäische Union kommen derzeit so viele Asylbewerber wie noch nie. Dabei sind die Schutzsuchenden recht ungleich auf die Mitgliedstaaten der EU verteilt: Große Länder wie das Vereinigte Königreich, Frankreich, Italien und Spanien haben eine relativ geringe Zahl von Asylbewerbern...