Interflectance calculations for various luminaires

Previous interflectance tables have dealt principally with three basic types of lighting (Types I, II, and III). The present paper extends the scope of the interflection method by showing how it can be applied to rooms lighted by hanging luminaires. It is found that most cases arising in practice can be covered by six canonic distributions. The effect of mounting height is handled by means of a simple equation.     

Radiant flux through apertures—I

Equations for the calculation of radiant power F through two apertures in series are well known. A characteristic of these formulae is that they give F as a small difference between two large terms. Evidently, the flux through the apertures must decrease as the spacing between them increases; and for large spacing, the inverse-square relation must hold. Instead of exhibiting this behaviour in an obvious manner, however, the traditional equations give the specious impression of an increase in F with increase in spacing. The paper develops an approximate formulae that applies to apertures in the shape of any regular polygon and that shows clearly how the inverse square relation is approached for large separation.     

Radiant Flux Through Apertures— III

This paper completes our treatment of radiant flux through pairs of apertures. In Part II, we obtained approximate equations for rectangular apertures in parallel planes, with the restriction that two apertures be identical and that one be directly above the other. Here we generalize to the case of any apertures that fit into a rectangular grid. The idea for this generalization originated with Ondracek but it is here expressed in matrix notation, which allows coefficients F_ij to be obtained rather simply.     

Enhancing the Executive Functions of 3‐Year‐Olds in the Dimensional Change Card Sort Task

Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3‐year‐olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that prior experience with the postswitch dimension can enhance 3‐year‐olds' performance in the DCCS. In Experiment 1A, a matching game was used to preexpose 3‐year‐olds (n = 36) to color. This facilitated switching from sorting by shape to color. In 3 , 3‐year‐olds (n = 18) were preexposed to shape. This did not facilitate switching from sorting by color to shape. The model was used to explain this asymmetry.     

Imagining a future,living in the present and remembering the past

The remit for this short piece was to identify themes emerging from the articles in this edition by Julie McLeod, Duncan Waite and Eugenie Samier, to consider how these themes reflect on the current field, and to identify their ongoing relevance. Additionally, I was asked to consider the current challenges that the field is facing and what this means for research and journals such as this one. My short response is that our research has to matter. It has to matter to us as individuals so that what we do is worthwhile; it has to matter that we can provide rigorous research that is reliable so that it can inform policy makers and administrators; and it has to provide teachers and students with a greater understanding of why they are doing what they are being asked to do.     

An application of pert to R & D scheduling

This paper deals with an application of PERT to R & D scheduling for the National Center for Drug Analysis, U. S. Food and Drug Administration. The Center is a pharmaceutical-chemistry laboratory having specialized functional responsibilities for research and development of analytical chemical procedures. The model was constructed based on the empirical data obtained at the Center for a five-year period. The model has been statistically tested and interpreted. It assists the management of the Center in developing a complete work-planning process and in controlling the project tasks, thus achieving the effective utilization of human and physical resources.