Temporal representation of state transitions

This paper describes a knowledge-based temporal representation of state transitions for industrial real-time systems. To allow expression of uncertainty, we shall define fluents as disjuncts of positive/negative time-varying properties. A state of the world is represented as a collection of fluents, which is usually incomplete in the sense that neither the positive form nor the negative form of some properties can be implied from it. The world under consideration is assumed to persist in a given state until an action(s) takes place to effect a transition of it into another state, where actions may either be instantaneous or durative. High-level causal laws are characterized in terms of relationships between actions and the involved world states. An effect completion axiom is imposed on each causal law to guarantee that all the fluents that can be affected by the performance of the corresponding action are governed. This completion requirement is practical for most industrial real-time applications and in fact provides a simple and effective treatment to the so-called frame problem.

Investigating the representation of merging behavior at the floor–stair interface in computer simulations of multi-floor building evacuations

In this article, the representation of the merging process at the floor— stair interface is examined within a comprehensive evacuation model and trends found in experimental data are compared with model predictions. The analysis suggests that the representation of floor—stair merging within the comprehensive model appears to be consistent with trends observed within several published experiments of the merging process. In particular: (a) The floor flow rate onto the stairs decreases as the stair population density increases. (b) For a given stair population density, the floor population's flow rate onto the stairs can be maximized by connecting the floor to the landing adjacent to the incoming stair. (c) In situations where the floor is connected adjacent to the incoming stair, the merging process appears to be biased in favor of the floor population. It is further conjectured that when the floor is connected opposite the incoming stair, the merging process between the stair and floor streams is almost in balance for high stair population densities, with a slight bias in favor of the floor stream at low population densities. A key practical finding of this analysis is that the speed at which a floor can be emptied onto a stair can be enhanced simply by connecting the floor to the landing at a location adjacent to the incoming stair rather than opposite the stair. Configuring the stair in this way, while reducing the floor emptying time, results in a corresponding decrease in the descent flow rate of those already on the stairs. While this is expected to have a negligible impact on the overall time to evacuate the building, the evacuation time for those higher up in the building is extended while those on the lower flows is reduced. It is thus suggested that in high-rise buildings, floors should be connected to the landing on the opposite side to the incoming stair. Information of this type will allow engineers to better design stair—floor interfaces to meet specific design objectives.

Legal myth-making: Medea and the legal representation of the feminine ‘other'

The Law operates by, and through, the creation of ideal benchmarks of conduct that are deemed to be representative of the behavioural norm. It is in this sense that it could be contended that the Law utilises, and relies on, myths in the same way as do other disciplines, notably psycho-analysis. It is possible to go even further and argue that the use of a created narrative mythology is essential to the establishment of a defined legal benchmark of behaviour by which the female defendant is assessed, judged and punished. While mythology expresses and symbolizes cultural and political behaviour, it is the Law that embodies and prescribes punitive sanctions. This element represents a powerful literary strand in classical mythology. This may be seen, for instance, in Antigone’s appeal to the Law as justification for her conduct, as much as in Medea’s challenge to the Law though her desire for vengeance. Despite its image of neutral, objective rationality, the Law, in creating and sustaining the ideals of legally-sanctioned conduct, engages in the same literary processes of imagination, reason and emotion that are central to the creation and re-creation of myth. The (re-)presentation of the Medea myth in literature (especially in theatre) and in art, finds its echo in the theatre of the courtroom where wronged women who have refused to passively accept their place, have instead responded with violence. Consequently, the Medea myth, in its depiction of the (un)feminine, serves as a template for the Law’s judgment of ‘conventional’ feminine conduct in the roles of wife and mother. Medea is an image of deviant femininity, as is Lady Macbeth and the countless other un-feminine literary and mythological women who challenge the power of the dominant culture and its ally, the Law. These women stand opposed to the other dominant theme of both literature and Law: the conformist woman, the passive dupe, who are victims of male oppression – women such as Ariadne of Naxos and Tess of the D’Ubervilles – and who are subsequently consumed by the Law, much as Semele is consumed by the fire of Jupiter’s gaze upon her. All of these women, the former as well as the latter, have their real-life counterparts in the pages of the Law Reports. As Fox puts it, “these women have come to bear the weight of the cultural stereotypes and preconceptions about women who kill.”

A new 14+: vocational diplomas and the future of schools, colleges and universities. An educational and campaigning pamphlet

Written in an accessible and campaigning style, this pamphlet affords a valuable context to the introduction of the first group of specialist diplomas for 14 year olds in September 2008. The diplomas are the latest in a line of failed initiatives that have sought to provide vocational ‘alternatives’ for those young people staying in full-time education and not considered ‘academic’. Rather than developing any useful employment skills, Allen and Ainley argue that their introduction reflects the changing significance of education in the division and social control of learners that now extends from school to college and on to university. Those who are opposed to the current post-14 agenda, must not only put forward radical alternatives to the current curriculum offer but also, the authors argue, address issues of democracy and accountability. To do this, teacher trade unionists must make new types of alliances with local communities and also with their students.