Front and back printed circuit layouts presented on single sheet

A diazo photographic process of clear plastic masters is used in reproducing front and back printed circuit layouts of differing intensity on a single sheet

Glue in the light-front pion

It may be possible to approximate the full pion wave function in light-front QCD using only q \qbar and q \qbar g Fock space components. Removing zero modes and using invariant-mass cutoffs that make a constituent approximation possible leads to non-canonical terms in the QCD hamiltonian, and forces us to work in the broken symmetry phase of QCD in which chiral symmetry breaking operators must appear directly in the hamiltonian because the vacuum is trivial. Assuming any candidate interactions are local in the transverse direction, I argue that they are probably relevant operators so that perturbation theory is not modified at high energies. Since light-front chiral symmetry corresponds to quark helicity conservation, we can readily identify candidate chiral symmetry breaking interactions. The only candidate relevant operator is the quark-gluon emission/absorption operator with a quark spin flip. I argue that this operator can only produce the physical $\pi-\rho$ mass splitting if the q \qbar g component of the pion is significant.Comment: LATEX, 6 pages. To appear in Proceedings of HD 2000, From Hadrons to String

Virtually connected, practically mobile

This is the post-print version of the Chapter. The official published version can be accessed from the links below - Copyright @ 2006 SpringerThis chapter addresses a central issue in studies of mobile work and mobile technology – what is the work of mobile workers, and how do they use the resources that they have to undertake this work (i.e. the work they have to do in order to do their work)? In contrast to many of the other papers in this collection, the objective of this chapter is to examine individual mobile work, and not teamwork and co-operation other than where it impacts on the work of individuals. We present data from a study of mobile workers, examining a range of mobile workers to produce a rich picture of their work. Our analysis reveals insights into how mobile workers mix their mobility with their work, home and social lives, their use of mobile technology, the problems – technological and otherwise – inherent in being mobile, and the strategies that they use to manage their work, time, other resources and availability. Our findings demonstrate important issues in understanding mobile work, including the maintenance of communities of practice, the role and management of interpersonal awareness and co-ordination, how environmental resources affect activity, the impact of mobility on family/social relationships and the crossover between the mobile workers’ private and working lives, how preplanning is employed prior to travel, and how mobile workers perform activity multitasking, for example through making use of ‘dead time’. Finally, we turn to the implications of this data for the design and deployment of mobile virtual work (MVW) technologies for individuals and a broader organisational context

Building an alternative social currency: Dematerialising and rematerialising digital money across media

This paper reports on the user experience and design of physical and digital forms of a mixed-media local currency. We reconceive digitally mediated transactions as social interactions and report on the development of conceptual designs informed by user research and interactive workshops. Our findings show that use is strongly tied to conceptions of locality and community, markers of identity, information exchange and the digital and physical forms as tools for shaping interactions. The form of the currency can make the invisible visible, exposing our identities and values, business models, and the details of the transactions themselves. Our analysis stresses the need to provide opportunities for extending social interaction, making more local connections and deriving the best value from those connections, without insulating individuals from each other, or from the wider geographical context. Themes that emerged from the user research were visualized as conceptual designs for digitally augmented media, allowing us to explore the monetary transaction at three levels: the material, as interaction between two parties, and the context of the transaction.The RCUK Digital Economy theme (EP/K012304/1)