Hyssopus officinalis L. (Lamiaceae family) has been cultivated in Central Europe for a long time. This essential oil containing species serves not only as spice but in many countries including… (More)

Concept maps, or mind maps as learning tools mirror the knowledge constructed through observation of events or objects in relation to the concepts already known. Different types of computer based… (More)

Today’s societies place challenging demands on individuals, who are confronted with complexity in many parts of their lives. What do these demands imply for key competencies that individuals need to… (More)

We calculate the S-matrix correlation function for chaotic scattering on quantum graphs and show that it agrees with that of random-matrix theory. We also calculate all higher S-matrix correlation… (More)

We investigate the spectral fluctuation properties of constrained ensembles of random matrices (defined by the condition that a number NQ of matrix elements vanish identically; that condition is… (More)

We complement a recent calculation (P.B. Gossiaux and the present authors, Ann. Phys. (N.Y.) in press) of the autocorrelation function of the conductance versus magnetic field strength for ballistic… (More)

For time-reversal invariant graphs we prove the Bohigas-Giannoni-Schmit conjecture in its most general form: For graphs that are mixing in the classical limit, all spectral correlation functions… (More)

For chaotic scattering on quantum graphs, the semiclassical approximation is exact. We use this fact and employ supersymmetry, the color-flavor transformation, and the saddle-point approximation to… (More)