The whole in a complex system is the sum of its parts, plus the interactions between the parts. Understanding social, biological, and economic systems therefore often depends on understanding their patterns of interactions—their networks. In this thesis, the approach is to understand complex systems by making simple network models with nodes and links. It is first of all an attempt to investiga...

In a recent paper Królak and Beem (1998 J. Math. Phys. at press) have shown differentiability of Cauchy horizons at all points of multiplicity one. In this note we give a simpler proof of this result. PACS numbers: 0420C, 0420G

In this paper, we use integer programming (IP) to compute minimal forecast horizons for the classical dynamic lot-sizing problem (DLS). As a solution approach for computing forecast horizons, integer programming has been largely ignored by the research community. It is our belief that the modelling and structural advantages of the IP approach coupled with the recent significant developments in ...

We examine how different investment horizons, and consequently the number of hands through which a security passes during its life, affect prices in a laboratory market populated by overlapping generations of investors. We find that (i) price deviations are larger in markets populated only by shorthorizon investors compared to markets with long-horizon investors; (ii) for a given maturity of se...

We examine in an experiment the causes, consequences and possible cures of myopic loss aversion (MLA) for investment behaviour under risk. We find that both, investment horizons and feedback frequency contribute almost equally to the effects of MLA. Longer investment horizons and less frequent feedback lead to higher investments. However, when given the choice, subjects prefer on average shorte...

In a space-time with cosmological constant Λ > 0 and matter satisfying the dominant energy condition, the area of a black or white hole cannot exceed 4π/Λ. This applies to event horizons where defined, i.e. in an asymptotically deSitter space-time, and to outer trapping horizons (cf. apparent horizons) in any space-time. The bound is attained if and only if the horizon is identical to that of t...

Manure-derived P can jeopardize surface water quality in regions dominated by sandy soils, due to low P retention capacity of these soils. Surface (Ap) horizons from dairy-intensive areas in the Lake Okeechobee Basin were recently found to release P readily, despite abundant Ca and high pH. The purpose of this study was to determine the inorganic components hat influence or reflect the stabilit...

In order to guarantee stability, known results for MPC without additional terminal costs or endpoint constraints often require rather large prediction horizons. Still, stable behavior of closed loop solutions can often be observed even for shorter horizons. Here, we make use of the recent observation that stability can be guaranteed for smaller prediction horizons via Lyapunov arguments if more...