This paper describes the application of heterogeneous algebraic system for the construction of the formal model of object database instead of object algebra. Complete formalization of the operation of intersection of class specifications is given.

The use of proof plans in formal methods Citation for published version: Bundy, A 1990, 'The use of proof plans in formal methods'. in A Miola (ed.), Design and implementation of General rights Copyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that ...

The traditional notion of the curriculum as a fixed list of topics to be studied sequentially is under strain as pressure for flexibility in education increases. However, curriculum flexibility can lead to curriculum complexity, hindering learners in the development of their competences. This article presents a formal model for the description of curricula, designed to underpin guidance support...

This article promotes a more complete understanding of social change by analyzing spatial patterns of contraceptive use in Bangladesh and the contiguous state of West Bengal in India. Multilevel analyses that control for variations in individual- and household-level correlates show an important role for cross-border influences only in those districts that share a common language across the bord...

There has been a significant increase in the number of twins and higher multiples so that one child in 33 is now a multiple. It is therefore not unusual for schools to have several sets of twins, as well as triplets and even higher multiples. By being the same age and in the same school year if not class, twins and higher multiples are not like brothers and sisters born closely together. Teache...

CONTEXT Few nationally representative studies have examined the prevalence and predictors of emergency contraception use or of receipt of counseling about the method. The impact of the U.S. Food and Drug Administration's 2006 approval of behind-the-counter sales of the method to women aged 18 and older remains to be seen; therefore, understanding patterns of use and counseling before the 2006 p...

costly. This paper investigated the manufacture of double crowned gears by traditional gear shaving machine. Taguchi Method was applied to find critical parameters in the shaving process and the transmission error had also been improved through the process of robust design.