A participatory action research study of key account management changes

Pure Participatory Action Research projects in the IMP research tradition are rather rare. This paper describes both the process and the outcomes of such a project carried out for a major business to retail firm in the UK. The issue at hand was, and is, Key Account Management, defined in a very broad way. The process is one of changing the ways in which the actors in the firm at different levels work together to try to coordinate the long term strategy and short term operations in relation to powerful retail customers. The outcomes for the firm have, so far, been very positive. The outcomes for the researchers are too early to fully evaluate but look very promising

Quantum walks with encrypted data

In the setting of networked computation, data security can be a significant concern. Here we consider the problem of allowing a server to remotely manipulate client supplied data, in such a way that both the information obtained by the client about the server's operation and the information obtained by the server about the client's data are significantly limited. We present a protocol for achieving such functionality in two closely related models of restricted quantum computation -- the Boson sampling and quantum walk models. Due to the limited technological requirements of the Boson scattering model, small scale implementations of this technique are feasible with present-day technology.Comment: 4 pages, 2 figure

Risk and benefits in lifestyle sports: parkour, law and social value

This paper examines the interrelationship between law and lifestyle sports, viewed through the lens of parkour. We argue that the literature relating to legal approaches to lifestyle sport is currently underdeveloped and so seek to partially fill this lacuna. Hitherto, we argue, the law has been viewed as a largely negative presence, seen particularly in terms of the ways in which counter-cultural activities are policed and regulated, and where such activities are viewed as transgressive or undesirable. We argue that this is a somewhat unsophisticated take on how the law can operate, with law constructed as an outcome of constraints to behaviour (where the law authorises or prohibits), distinct from the legal contexts, environments and spaces in which these relationships occur. We argue that the distinctive settings in which lifestyle sports are practiced needs a more fine-grained analysis as they are settings which bear, and bring to life, laws and regulations that shape how space is to be experienced. We examine specifically the interrelationship between risk and benefit and how the law recognises issues of social utility or value, particularly within the context of lifestyle sport. We seek to move from user-centred constructions of law as an imposition, to a more nuanced position that looks at parkour at the intersections of law, space and lifestyle sport, in order to reveal how law can be used to support and extend claims to space

Research on computational and display requirements for human control of space vehicle boosters. Part I - Theory and results Final report, 1 Mar. - 31 Aug. 1967

Optimization study of computation and display requirements for human control of reusable orbital transport ascen

Critical decay index at the onset of solar eruptions

Magnetic flux ropes are topological structures consisting of twisted magnetic field lines that globally wrap around an axis. The torus instability model predicts that a magnetic flux rope of major radius $R$ undergoes an eruption when its axis reaches a location where the decay index $-d(\ln B_{ex})/d(\ln R)$ of the ambient magnetic field $B_{ex}$ is larger than a critical value. In the current-wire model, the critical value depends on the thickness and time-evolution of the current channel. We use magneto-hydrodynamic (MHD) simulations to investigate if the critical value of the decay index at the onset of the eruption is affected by the magnetic flux rope's internal current profile and/or by the particular pre-eruptive photospheric dynamics. The evolution of an asymmetric, bipolar active region is driven by applying different classes of photospheric motions. We find that the critical value of the decay index at the onset of the eruption is not significantly affected by either the pre-eruptive photospheric evolution of the active region or by the resulting different magnetic flux ropes. As in the case of the current-wire model, we find that there is a `critical range' $[1.3-1.5]$, rather than a `critical value' for the onset of the torus instability. This range is in good agreement with the predictions of the current-wire model, despite the inclusion of line-tying effects and the occurrence of tether-cutting magnetic reconnection.Comment: 15 pages, 9 figures. To appear in The Astrophysical Journa

Do Stock Price Bubbles Influence Corporate Investment?

Building on recent developments in behavioral asset pricing, we develop a model in which dispersion of investor beliefs under short-selling constraints drives a firm's stock price above its fundamental value. Managers optimally respond to the stock market bubble by issuing new equity. The bubble reduces the user-cost of capital and increase real investment. Using the variance of analysts' earnings forecasts as a proxy for the dispersion of investor beliefs, we find strong empirical support for the model's key prediction that increases in dispersion cause increases in new equity issuance, Tobin's Q, and real investment.

Scalable boson-sampling with time-bin encoding using a loop-based architecture

We present an architecture for arbitrarily scalable boson-sampling using two nested fiber loops. The architecture has fixed experimental complexity, irrespective of the size of the desired interferometer, whose scale is limited only by fiber and switch loss rates. The architecture employs time-bin encoding, whereby the incident photons form a pulse train, which enters the loops. Dynamically controlled loop coupling ratios allow the construction of the arbitrary linear optics interferometers required for boson-sampling. The architecture employs only a single point of interference and may thus be easier to stabilize than other approaches. The scheme has polynomial complexity and could be realized using demonstrated present-day technologies.Comment: 7 pages, 7 figure

The unsteady flow of a weakly compressible fluid in a thin porous layer. I: Two-dimensional theory

We consider the problem of determining the pressure and velocity fields for a weakly compressible fluid flowing in a two-dimensional reservoir in an inhomogeneous, anisotropic porous medium, with vertical side walls and variable upper and lower boundaries, in the presence of vertical wells injecting or extracting fluid. Numerical solution of this problem may be expensive, particularly in the case that the depth scale of the layer h is small compared to the horizontal length scale l. This is a situation which occurs frequently in the application to oil reservoir recovery. Under the assumption that epsilon=h/l<<1, we show that the pressure field varies only in the horizontal direction away from the wells (the outer region). We construct two-term asymptotic expansions in epsilon in both the inner (near the wells) and outer regions and use the asymptotic matching principle to derive analytical expressions for all significant process quantities. This approach, via the method of matched asymptotic expansions, takes advantage of the small aspect ratio of the reservoir, epsilon, at precisely the stage where full numerical computations become stiff, and also reveals the detailed structure of the dynamics of the flow, both in the neighborhood of wells and away from wells