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Colorcurve (D65/1964) and Coloroid (C/1931) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the Colorcurve and Coloroid notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples. Colorcurve notations are derived from the OSA-UCS aim points, and Coloroid notations are derived from colorimetric data of the OSA-UCS samples contained in MacAdam's copy of the OSA-UCS colour atlas.

This article describes a further investigation into the accuracy of the samples that comprise the NCS colour atlas. Earlier research has demonstrated that the NCS atlas samples are, on average, more inaccurate than the samples that comprise other comparable colour atlases. The present work identifies areas of the NCS colour atlas containing coloured samples that significantly deviate from their intended aim points.

The term ‘data model’ is used to describe the conceptual view of how data which purports to model reality is arranged in a computer system. A ‘data structure’ is the logical view, and a ‘file structure’ is the actual physical arrangement of the data. Spatial data, as used in geographic information systems, gives rise to particular problems in deriving suitable data models and structures because of the diverse sources and applications of the data. This paper discusses some of these problems and puts forward some pragmatic solutions.

In 1985 a research program was instigated to determine the feasibility and desirability of developing a computer based colour notation conversion program. Results indicated that the development of such a program covering the Munsel, NCS, DIN, OSA-UCS, Coloroid, CIELAB and CIELUV colour specification systems for use as a research tool was both feasible and desirable. The program was completed early in 1989 and this is the first of a number of articles that uses this program as a research tool. The colour notation conversion program has been used to evaluate the accuracy of the samples which comprise the NCS, DIN and OSA-UCS colour atlases.

In this investigation dielectric constant and loss tangent values of coal samples were computed from measurements made at microwave frequencies (8.2–12.4 GHz). Two different waveguide methods were used in the measurements. One technique utilized a finite sample and two reactive terminations, and the other required the use of an infinite sample simulated in the laboratory by a very long specimen. For each of the two Pittsburgh seam coal samples, dielectric constant and loss tangent variations were also measured as a function of moisture. Typical moisture contents of 10% and 15% were examined. Electromagnetic propagation through a single layer of coal seam was then investigated analytically as a function of coal depth.