Using social engagement to inspire design learning

Social design and ‘design for need’ are important frameworks for establishing ethical understanding amongst novice product designers. Typically, product design is a value-adding activity where normally aesthetics, usability and manufacturability are the key agendas. Howard [1] in his essay “Design beyond commodification” discusses the role of designers in contributing to cultural expressions designed to influence consumer aspirations and desires. He argues that designers are impelled “to participate in the creation of lifestyles that demand the acquisition of goods as a measure of progress and status.” As emerging consumers, student designers tend to reflect this consumer culture in their work, seeking to add ‘marketability’ by focusing on aesthetic development. However value adding can occur in many different manifestations, often outside commercial expectations and the students’ experience. Projects that may be perceived as having limited market potential can often have significant personal impact for both recipient and designer. Social engagement provides a valuable insight for design students into the potential of design to contribute solutions to societal well-being, rather than serve market forces. Working in a local context can enhance this, with unlimited access to end users, their environs and the product context, enabling the development of user empathy and a more intgrated collaborative process. The ‘Fixperts’ social project discussed in this paper has proved to be an effective method of engaging undergraduate students in participatory design within their local community. This model for social engagement has provided an unprecedented learning experience, and established a strong ethical framework amongst Brunel design students

Covariant four-dimensional scattering equations for the NN−πNNNN-\pi NN system

We derive a set of coupled four-dimensional integral equations for the $NN-\pi NN$ system using our modified version of the Taylor method of classification-of-diagrams. These equations are covariant, obey two and three-body unitarity and contain subtraction terms which eliminate the double-counting present in some previous four-dimensional $NN-\pi NN$ equations. The equations are then recast into a from convenient for computation by grouping the subtraction terms together and obtaining a set of two-fragment scattering equations for the amplitudes of interest.Comment: Version accepted for publication in ``Annals of Physics''. New section containing two new figures added. 58 pages, 20 figures. Uses RevTeX. For copies of figures email [email protected]

R-matrix Approach to Quantum Superalgebras su_{q}(m|n)

Quantum superalgebras $su_{q}(m\mid n)$ are studied in the framework of $R$-matrix formalism. Explicit parametrization of $L^{(+)}$ and $L^{(-)}$ matrices in terms of $su_{q}(m\mid n)$ generators are presented. We also show that quantum deformation of nonsimple superalgebra $su(n\mid n)$ requires its extension to $u(n\mid n)$.Comment: 14 page

The classification of diagrams in perturbation theory

The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor's method which require clarification. Firstly, it is not clear whether Taylor's original method is equivalent to the simpler classification-of-diagrams scheme used by Thomas, Rinat, Afnan and Blankleider (TRAB). Secondly, when the Taylor method is applied to certain problems in a time-dependent perturbation theory it leads to the over-counting of some diagrams. This paper first restates Taylor's method, in the process uncovering reasons why certain diagrams might be double-counted in the Taylor method. It then explores how far Taylor's method is equivalent to the simpler TRAB method. Finally, it examines precisely why the double-counting occurs in Taylor's method, and derives corrections which compensate for this double-counting.Comment: 50 pages, RevTeX. Major changes from original version. Thirty figures available upon request to [email protected]. Accepted for publication in Annals of Physic

Controlling Reversibility in Reversing Petri Nets with Application to Wireless Communications

Petri nets are a formalism for modelling and reasoning about the behaviour of distributed systems. Recently, a reversible approach to Petri nets, Reversing Petri Nets (RPN), has been proposed, allowing transitions to be reversed spontaneously in or out of causal order. In this work we propose an approach for controlling the reversal of actions of an RPN, by associating transitions with conditions whose satisfaction/violation allows the execution of transitions in the forward/reversed direction, respectively. We illustrate the framework with a model of a novel, distributed algorithm for antenna selection in distributed antenna arrays.Comment: RC 201

Space Shuttle orbiter trimmed center-of-gravity extension study

Aerodynamic, heat transfer, and system design studies to determine removable modifications for the Space Shuttle orbiter that would extend its forward center-of-gravity triom capability are summarized. Wind-tunnel tests were conducted at Mach numbers ranging from 0.25 to 20.3 to determine the most effective aerodynamic modifications. Heat transfer and system design studies determined the impact of the modifications on the thermal protection system and structural weight of the vehicle. The most effective modifications were in-fillet canards or a forward extension of the existing forward wing fillet