A two-sector growth model with institutional saving and investment

This paper develops a two-sector growth model in which institutional investors play a significant role. A necessary and sufficient condition is established under which these investors own the entire capital stock in the long run. The dependence of the long-run growth rate on the behaviour of such investors, and the effects of a productivity increase are analysed

Two-Dimensional Product Differentiation Under Duopoly: An Application to Product and Service Reliability

Under oligopoly firms are often observed to specialise their production, with some firms producing highly reliable output and offering good warranty deals, while others produce less reliable output and offer less attractive warranties, but charge a lower price. This paper develops an approach to product/service reliability which provides an alternative to the conventional analysis based on the characteristics approach. The model of this paper defines reliability as the objective probability of product failure, not as a characteristic of individual goods. Reliability, thus defined, is treated as a choice variable of the firm, and consumers’ preferences are partially endogenised. This approach to reliability is incorporated into a duopoly model which explains the phenomenon of specialisation described above. The model is applicable to the markets for consumer durables, some intermediate goods and some services.Reliability, duopoly.

A Model of Endogenous Quality Management

This paper is concerned with product quality, defined as a kind of durability. Existing models of product quality (in the sense considered here) depend on the idea of signalling, itself driven by an informational asymmetry dictated by “Nature”. The paper proposes an alternative approach, which endogenises the quality managment process. A model is developed which is applicable to the markets for consumer durables and for some intermediate goods. Both competitive and monopolistic markets are considered, and some comparative static results are obtained.

Stability of Growth Models with Generalised Lag Structures

This paper considers the lag structures of dynamic models in economics, arguing that the standard approach is too simple to capture the complexity of actual lag structures arising, for example, from production and investment decisions. It is argued that recent (1990s) developments in the the theory of functional differential equations provide a means to analyse models with generalised lag structures. The stability and asymptotic stability of two growth models with generalised lag structures are analysed. The paper concludes with some speculative discussion of time-varying parameters.

Anaesthetic breathing circuit obstruction due to blockage of tracheal tube connector by a foreign body - two cases

Publisher's copy made available with the permission of the publisher© 1999 Australian Society of AnaesthetistsTwo cases are presented which illustrate the disastrous consequences possible when an anaesthetic breathing circuit is obstructed by a foreign body. Despite reports of previous similar cases, work practices and equipment manufacture or design continue to allow for such events to occur. The importance of both pre-anaesthetic testing of the entire circuit including attachments such as the tracheal tube connector and filters, and the removal of these parts should obstruction occur, is emphasised. Use of “clear” transparent breathing circuit components and opaque or brightly coloured packaging and caps which could potentially cause obstruction should decrease the incidence and facilitate the diagnosis of this problem.M.J. Foreman, D. G. Moye

Scattering of a Plane Acoustical Wave by a Spherical Obstacle

The long-time behavior of the scattered field produced by a plane acoustical pulse stalking a spherical obstacle is investigated. Incident pulses are taken that represent a unit step in potential (or equivalently delta function pulse in pressure), an arbitrary potential pulse of finite duration, and an arbitrary pressure pulse of finite duration. Both hard and soft spheres are considered. In addition, a pulse consisting of a unit step in velocity impinging on a hard sphere is examined. In each case, the time rate of decay to the steady state is established. This is seen to be controlled by the zeroes of certain naturally occurring special polynomials that arise because of the spherical geometry and are independent of the shape of the incident pulse

Money and inflation in a nonlinear model

A nonlinear model of inflation and growth, with a fixed rate of money growth, is developed and its global dynamics analysed. These are compared with the local, linearised dynamics of the model. It is shown that the global dynamics of the model plausibly predict hyperinflationary bubbles, which are not present in the linearised version. Numerical simulations of the model are presented.Money, inflation, nonlinearity.

Evaluation of three tractor-guidance methods for parallel swathing at two field speeds

This study compared the accuracy (mean error and rms error) and precision (standard deviation of error) of three tractor-guidance methods (foam-marker, light-bar, and assisted-steering systems) at two field speeds (5.6 – and 11.5 km/h) for parallel swathing operations. Eighty-four replications of each combination of guidance method and field speed were conducted between 15 October and 22 December 2006 (504 total field passes). The foam-marker system was found to be significantly less accurate [larger mean error (p \u3c .0001) and had a larger rms error (p \u3c .0001)] than either the light-bar or the assisted-steering system. There was no significant difference in mean error (p = .6718) or rms error (p = .8841) by field speed. There was a significant interaction between guidance method and field speed for both mean error (p = .0009) and rms error (p = .003). Mean and rms errors for the foam-marker and the assisted-steering systems increased at higher field speed, while the mean and rms errors for the light-bar system decreased at higher speed. The assisted-steering system had a significantly lower (p = .0164) standard deviation of error (higher precision) than the foam-marker or the light-bar systems. There was no significant difference in the standard deviation of error by field speed (p = .6258) or by the interaction of guidance method and field speed (p = .2748)