The model validator’s manifesto

Victory Idowu proposes a model validator’s manifesto— principles for model validation that enshrine best practice for actuarial models

Convergence of the multigroup approximations for subcritical slab media with applications to shielding calculations

AbstractThe stability, convergence, and consistency properties of the steady-state multigroup model are investigated for subcritical slab media. These concepts are defined in a Banach space setting in which the norm of the angular flux yields the maximum value, over the position and angular variables, of the energy-integrated angular flux. It is shown that the multigroup approximations are stable, and are both consistent with, and convergent to, the transport equation under the conditions that the maximum fluctuations in the total cross section, and in the number of secondary particles arising from each energy level, tend to zero as the energy mesh becomes finer. These results in this particular Banach space setting extend to slab transport those results obtained by P. Nelson in a shielding norm setting for multigroup transport in submultiplying rod media

The effect of prior victory or defeat in the same site as that of subsequent encounter on the determination of dyadic dominance in the domestic hen

We examined the effect of prior victory or defeat in the same site as that of a subsequent encounter on the outcome of dyadic encounter of domestic hens by placing them in two situations: In the first set of dyads, two unacquainted hens having experienced prior victory were introduced in the site where one had experienced victory. In the second set, two unacquainted hens having experienced defeat were introduced in the site where one had recently lost. Results indicate that victories are equally shared between individuals with prior victory experiences, while familiarity with the meeting site did not give any advantage. However, hens having previously lost were disadvantaged when the encounter occurred in the same site as that of their prior defeat. This demonstrates that previous social experience in a site is more important on the outcome of subsequent encounters for losers than winners. Losers seem to associate the site with the stressful effect of losing or being more easily dominated