A note on the modelling of hyper-inflations

In time series macroeconometric models, the first difference in the logarithm of a variable is routinely used to represent the rate of change of that variable. It is often overlooked that the assumed approximation is accurate only if the rates of change are small. Models of hyper-inflation are a case in point, since in these models, by definition, changes in price are large. In this letter, Cagan’s model is applied to Hungarian hyper-inflation data. It is then demonstrated that use of the approximation in the formation of the price inflation variable is causing an upward bias in the model’s key parameter, and therefore an exaggeration of the effect postulated by Cagan

Nonlinear effects in optical data processing Final progress report

Nonlinearity effects in optical data processing, and FORTRAN program for analyzing nonlinearities in spectroscopic photographic plate

The standardisation of conflicts of laws rules for intermediated securities within the EU: Holy Grail or red herring?

The quest to standardise conflicts of laws rules for intermediated securities is fraught with difficulty. Whilst harmonisation will provide certainty in the market place, its critics argue that its introduction impinges on substantive rules of property law. This matter has vexed policymakers and academics for almost two decades and, despite the development by UNIDROIT of the Geneva Convention on Substantive Rules for Intermediated Securities, is at an impasse. In the light of the EU’s recent consultation on conflicts of laws rules for third party effects of transactions in securities and claims, this paper will reflect upon the discussion thus far and consider whether there is a need for overarching reform in this area of law at EU level, mindful that the EU forms only part of the global market place. Through a critical analysis of the consultation proposals, a consideration of the ‘real world’ experience of the courts and the application of complexity theory as a tool of normative reconstruction, this paper provides a new perspective to the debate and argues that, whilst some minor reforms may be appropriate, overarching reform in this area is unnecessary

The effect of non-linearities on optical correlation processing

Analytical method using series expansion to determine effect of nonlinearities on output of coherent optical correlato

Don't discredit law schools offering the LPC or BPTC

Responsible law schools guide and advise their law students on what step to take next, not let them be led astray by unsuitable alternatives to qualification, says Paula Moffatt

Regulation of insolvency practitioners

The SRA has decided that it will no longer regulate solicitor insolvency practitioners, but is this decision up to the SRA at all, asks Paula Moffatt

Optimization of the magnetic dynamo

In stars and planets, magnetic fields are believed to originate from the motion of electrically conducting fluids in their interior, through a process known as the dynamo mechanism. In this Letter, an optimization procedure is used to simultaneously address two fundamental questions of dynamo theory: "Which velocity field leads to the most magnetic energy growth?" and "How large does the velocity need to be relative to magnetic diffusion?" In general, this requires optimization over the full space of continuous solenoidal velocity fields possible within the geometry. Here the case of a periodic box is considered. Measuring the strength of the flow with the root-mean-square amplitude, an optimal velocity field is shown to exist, but without limitation on the strain rate, optimization is prone to divergence. Measuring the flow in terms of its associated dissipation leads to the identification of a single optimal at the critical magnetic Reynolds number necessary for a dynamo. This magnetic Reynolds number is found to be only 15% higher than that necessary for transient growth of the magnetic field.Comment: Optimal velocity field given approximate analytic form. 4 pages, 4 figure

Revenue Management in Multi-Firm, Multi-Product Price Competition

Dynamic pricing models in revenue management lack the ability to have multiple firms selling multiple product classes. In this thesis, a framework is created that allows for the construction of revenue management models with multiple firms, each selling multiple product types and where the firms have the ability to alter their prices instantly based on market conditions. The framework is a finite repeated game, where the optimal price for each state can be calculated through backwards induction. Conditions for existence of pure strategy Nash Equilibria are proven and conditions for unique pure strategy Nash Equilibria are discussed. We illustrate the pricing dynamics in a 2x1 and a 2x3 model. We recreate the well-known Netessine and Shumsky airline duopoly model but allow the firms to use dynamic pricing rather than booking limits. We find that in all cases the revenues from a dynamic pricing approach exceed those from booking limits. Through the use of three examples we show that our model provides vastly increased revenues over traditional models as it considers cross-price elasticities and how firms should alter their prices in response to the quantity levels of all products in the market

Bibliography on Optical Information and Data Processing

Bibliography on optical information and data processin