Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) t...

Although at the moment electronic payment via the Internet has no major impact on e-commerce sites, it will be a prerequisite for new business models, such as pay-per-view, and necessary for the success and cost efficiency of future e-commerce applications. Many payment protocols and frameworks for various business domains exist. However, they are incompatible which makes it hard for service de...

The formal mathematical definition of a Jordan curve (a non-self-intersecting continuous loop in the plane) is so simple that one is often lead to the unimaginative view that a Jordan curve is nothing more than a circle or an ellipse. In this paper, we continue a discussion of others [1, 2, 9, 11] that a Jordan curve can be quite fantastical both in some bizarre properties such a curve might ha...

The parabolic Anderson problem is the Cauchy problem for the heat equation ∂tu(t, z) = ∆u(t, z) + ξ(z)u(t, z) on (0,∞) × Z with random potential (ξ(z) : z ∈ Z). We consider independent and identically distributed potential variables, such that Prob(ξ(z) > x) decays polynomially as x ↑ ∞. If u is initially localised in the origin, i.e. if u(0, x) = 1l0(x), we show that, at any large time t, the ...

This paper discusses Pareto efficient allocations of an environmental commodity, which is both a public good and a public bad, with an application to the Scandinavian problem of conserving wild predators that are killing semi-domesticated reindeer. The paper begins by briefly outlining this conflict. This is followed by a theoretical analysis employing a diagrammatic tool called the Kolm triang...

Modern high-level programming languages often contain constructs whose semantics are non-trivial. In practice however, software developers generally restrict the use of such constructs to settings in which their semantics is simple (programmers use language constructs in ways they understand and can reason about). As a result, when developing tools for analyzing and manipulating software, a dis...

The renewable energy sources such as PV modules, fuel cells or energy storage devices such as super capacitors or batteries deliver output voltage at the range of around 12 to 70 VDC. In order to connect them to the grid the voltage level should be adjusted according to the electrical network standards in the countries. First of all the voltage should be stepped up to sufficient level at which ...