The shadow in the balance sheet: The spectre of Enron and how accountants use the past as a psychological defence against the future

Accounting frameworks play a crucial role in enabling us to make sense of business. These frameworks provide a common language for individuals, organizations and broader economic groupings to understand and make decisions about the commercial realm in which they operate. From a psychodynamic perspective, the language of accounting also plays an important role. On the one hand it offers a way to tame the uncertainty and unknowability of the future by representing it in the same comforting terms as it does the past, thus reducing anxiety. Accounting provides a ‘shorthand’, which achieves a balance between positive and negative, debit and credit, asset and liability. On the other hand, accounting can also provide an arena in which fantasies about the future can be staged. However, the use of accounting language is problematic, particularly when it comes to dealing with the future. First, accounting frameworks are inherently backward looking and second, the reassuring sense of clarity and predictability they give are bought at the price of unrealistic simplification. The shadow is never far away and is a constant source of surprises in the unfolding future of a business. Rationalizing and sanitizing the shadow through accounting language may alleviate anxiety but fails to provide an escape from its effects, and echoes from the shadow side of business are capable of shaking the world in the form of accounting scandals. Governments and businesses have reacted to scandals such as Enron and Worldcom by tightening legislation and refining accounting standards but little, if anything, has been done to bring us any closer to confronting the shadow of business where these scandals have their r

Yang-Lee zeros of the Q-state Potts model in the complex magnetic-field plane

The microcanonical transfer matrix is used to study the distribution of Yang-Lee zeros of the $Q$-state Potts model in the complex magnetic-field ($x=e^{\beta h}$) plane for the first time. Finite size scaling suggests that at (and below) the critical temperature the zeros lie close to, but not on, the unit circle with the two exceptions of the critical point $x=1$ ($h=0$) itself and the zeros in the limit T=0.Comment: REVTeX, 12 pages, 5 figures, to appear in Phys. Rev. Let

Modelling the aerodynamics of coaxial helicopters : from an isolated rotor to a complete aircraft

This paper provides an overview of recent research on the aerodynamics of coaxial rotors at the Rotorcraft Aeromechanics Laboratory of the Glasgow University Rotorcraft Laboratories. The Laboratory's comprehensive rotorcraft code, known as the Vorticity Transport Model, has been used to study the aerodynamics of various coaxial rotor systems. Modelled coaxial rotor systems have ranged from a relatively simple twin two-bladed teetering configuration to a generic coaxial helicopter with a stiff main rotor system, a tail-mounted propulsor, and a horizontal stabiliser. Various studies have been performed to investigate the ability of the Vorticity Transport Model to reproduce the detailed effect of the rotor wake on the aerodynamics and performance of coaxial systems, and its ability to capture the aerodynamic interactions that arise between the various components of realistic, complex, coaxial helicopter configurations. It is suggested that the use of such a numerical technique not only allows insight into the performance of such rotor systems but might also eventually allow the various aeromechanical problems that often beset new helicopter designs of this type to be circumvented at an early stage in their design

Microcanonical Transfer Matrix Study of the Q-state Potts Model

The microcanonical transfer matrix is used to study the zeros of the partition function of the Q-state Potts model. Results are presented for the Yang-Lee zeros of the 3-state model, the Fisher zeros of the 3-state model in an external field $H_q<0$, and the spontaneous magnetization of the 2-state model. In addition, we are able to calculate the ground-state entropy of the 3-state model and find $s_0=0.43153(3)$ in excellent agreement with the exact value, 0.43152...Comment: 3 pages, 3 figures, LaTeX, to appear in Computer Physics Communication

A generalization of Alternating Sign Matrices

In alternating sign matrices the first and last nonzero entry in each row and column is specified to be +1. Such matrices always exist. We investigate a generalization by specifying independently the sign of the first and last nonzero entry in each row and column to be either a +1 or a -1. We determine necessary and sufficient conditions for such matrices to exist.Comment: 14 page

Effect of rotor stiffness and lift offset on the aeroacoustics of a coaxial rotor in level flight

The acoustic characteristics of a twin contra-rotating coaxial rotor configuration with significant flapwise stiffness are investigated in steady forward flight. The Vorticity Transport Model is used to simulate the aerodynamics of the rotor system and the acoustic field is determined using the Ffowcs Williams-Hawkings equation implemented using the Farassat-1A formulation. Increasing the hub stiffness alters the strengths of the blade vortex interactions, particularly those between the upper and lower rotors, and affects the intensity and directivity of the blade vortex interaction noise produced by the system. The inter-rotor blade vortex interaction on the advancing side of the lower rotor is the principal source of the most intensively focused noise that is generated by a conventionally articulated coaxial rotor system. For stiffened coaxial rotors, this particular inter-rotor blade vortex interaction is weakened as a result of a broad redistribution in lateral loading, yielding a reduction in the intensity of the noise that is produced by this interaction. The spanwise distribution of loading on the rotors of a stiffened coaxial system can be modified further by altering the lateral partition of lift (or lift offset). It is shown that decreasing the lift offset has the effect of counteracting the redistribution of loading due to flapwise stiffness and hence increases the blade vortex interaction noise as well as the power consumed by the rotor. Conversely, a reduction in both the power consumption and the blade vortex interaction noise is observed if the lift offset is increased, with the maximum benefit of lift offset being achieved at high speed. The computational results suggest that the noise from the dominant inter-rotor blade vortex interaction can be ameliorated through the use of lift offset control on stiffened coaxial systems, to the extent that the noise produced by this interaction can be made to be comparable to that produced by the other, weaker interactions between the two rotors of the system