Abstract

Pressures are increasing on organisations to take an early and more systematic approach to security. A key to enforcing security is to restrict access to valuable assets. We regard access policies as security requirements that specify such restrictions. Current requirements engineering methods are generally inadequate for eliciting and analysing these types of requirements, because they do not allow complex organisational structures and procedures that underlie policies to be represented adequately. This paper discusses roles and why they are important in the analysis of security. The paper relates roles to organisational theory and how they could be employed to define access policies. A framework is presented, based on these concepts, for analysing access policies. q

Abstract

The lack of rank change in growth characteristics when open-pollinated families of loblolly pine (Pinus taeda L.) are planted on different sites in the Southeast has greatly simplified breeding for superior genotypes. Although family rank does not usually change, genotype by environment interactions (GxE) may be very important in operational deployment of families in regeneration programs. Using data from GxE trials and two site preparation-fertilization-herbicide trials, we estimated the growth that different families should achieve following application of these silvicultural practices. Better performing families tend to be most responsive to site changes (i.e. genetically unstable). Growth responses to silvicultural treatment will be overestimated if only the most responsive families are used in silvicultural research trials. Similarly, genetic gains will be overestimated if gain trials are planted on only the best sites or receive intensive culture. South. J. Appl. For. 21(2):84-89.

No abstract