Is a Dominant Service-Centric Sector Good for Diversity of Provision?

An obvious assumption underpinning the immense interest in service-oriented computing is that it is an inherently Good Thing, by which we mean that robust processes and tools for developing service-based systems will bring benefits for service providers and service consumers. The arguments, in terms of consumer choice and flexibility, are certainly quite convincing. However, in this position paper, we question the nature of the underlying assumption, in a world where requirements are as many and varied as potential users and ask if safeguards are needed to ensure that diversity of provision is maintained

Initial post-buckling behavior of toroidal shell segments

Initial post-buckling behavior of toroidal shell segment

On relations between one-dimensional quantum and two-dimensional classical spin systems

We exploit mappings between quantum and classical systems in order to obtain a class of two-dimensional classical systems with critical properties equivalent to those of the class of one-dimensional quantum systems discussed in a companion paper (J. Hutchinson, J. P. Keating, and F. Mezzadri, arXiv:1503.05732). In particular, we use three approaches: the Trotter-Suzuki mapping; the method of coherent states; and a calculation based on commuting the quantum Hamiltonian with the transfer matrix of a classical system. This enables us to establish universality of certain critical phenomena by extension from the results in our previous article for the classical systems identified.Comment: 36 page

Buckling of imperfect cylindrical shells under axial compression and external pressure

Axisymmetric deformation effects on cylindrical shell buckling under axial compressio

Fisher Hartwig determinants, conformal field theory and universality in generalised XX models

We discuss certain quadratic models of spinless fermions on a 1D lattice, and their corresponding spin chains. These were studied by Keating and Mezzadri in the context of their relation to the Haar measures of the classical compact groups. We show how these models correspond to translation invariant models on an infinite or semi-infinite chain, which in the simplest case reduce to the familiar XX model. We give physical context to mathematical results for the entanglement entropy, and calculate the spin-spin correlation functions using the Fisher-Hartwig conjecture. These calculations rigorously demonstrate universality in classes of these models. We show that these are in agreement with field theoretic and renormalization group arguments that we provide

Nonlinear quantum optical computing via measurement

We show how the measurement induced model of quantum computation proposed by Raussendorf and Briegel [Phys. Rev. Letts. 86, 5188 (2001)] can be adapted to a nonlinear optical interaction. This optical implementation requires a Kerr nonlinearity, a single photon source, a single photon detector and fast feed forward. Although nondeterministic optical quantum information proposals such as that suggested by KLM [Nature 409, 46 (2001)] do not require a Kerr nonlinearity they do require complex reconfigurable optical networks. The proposal in this paper has the benefit of a single static optical layout with fixed device parameters, where the algorithm is defined by the final measurement procedure.Comment: 14 pages, 4 figures, 4 table

Dynamic buckling estimates

Dynamic buckling estimates for sensitive structures subjected to finite-time loadin