Lessons from LHC elastic and diffractive data

We discuss a model which gives a `global' description of the wide variety of high-energy elastic and diffractive data that are presently available, particularly from the LHC experiments. The model is based on only one pomeron pole, but includes multi-pomeron interactions. Significantly, the LHC measurements require that the model includes the transverse momentum dependence of the intermediate partons as a function of their rapidity, which results in a rapidity (or energy) dependence of the multi-pomeron vertices.Comment: 9 pages, 2 figures, To be published in the Proceedings of the International Workshop on Particle Physics Phenomenology in memory of Alexei Kaidalov, Moscow, 21-25 July, 201

Defence science and innovation: an affordable strategic advantage

Overview: Australia’s neighbours in the Asia–Pacific are building high-quality science, technology, engineering and mathematics research capacities and infrastructure. As a consequence, Australia’s technological advantage in the defence domain is eroding. To recover that advantage, our policy should be to make the most of the knowledge, capability and capacity in Australia’s civilian science and innovation sector.  This special report analyses current and prospective Australian science, industry and defence science and innovation policy

Inventory Behavior in Durable-Goods Manufacturing: The Target-Adjustment Model

macroeconomics,inventory behavior, durable-goods manufacturing

TRUST IN TRANSITION: CROSS COUNTRY AND FIRM EVIDENCE

This paper uses data from a large survey of firms across 26 transition countries to examine the determinants of trust in the transition process. We first introduce a new measure of trust between firms: the level of prepayment demanded by suppliers from their customers in advance of delivery. Using this new measure, we confirm earlier findings that trust is higher where firms have confidence in third party enforcement through the legal system. However, the fairness and honesty of the courts are a more important determinant of interfirm trust than are the courts’ efficiency or ability to enforce decisions. We then examine the role of business networks in building trust and find that networks based around personal ties – family and friends – and business associations actively promote the development of trust, while business networks based on enterprise insiders and government agencies do not. Finally, we find that country-level effects are significantly more important determinants of interfirm trust than are firm-level effects.http://deepblue.lib.umich.edu/bitstream/2027.42/40026/3/wp640.pd

On the chromatic number of a random hypergraph

We consider the problem of $k$-colouring a random $r$-uniform hypergraph with $n$ vertices and $cn$ edges, where $k$, $r$, $c$ remain constant as $n$ tends to infinity. Achlioptas and Naor showed that the chromatic number of a random graph in this setting, the case $r=2$, must have one of two easily computable values as $n$ tends to infinity. We give a complete generalisation of this result to random uniform hypergraphs.Comment: 45 pages, 2 figures, revised versio

24/7 population modelling for enhanced assessment of exposure to natural hazards

There is a growing need for accurate spatio-temporal population estimates free from arbitrary administrative boundaries and temporal divisions to make enhanced assessments of population exposure to natural hazards. The approach proposed here combines the use of a spatio-temporal gridded population model to estimate temporary variations in population with natural hazard exposure estimations. It has been exemplified through a Southampton (UK) centred application using Environment Agency flood map inundation data. Results demonstrate that large fluctuations in the population within flood risk zones occur. Analysis indicates a diurnal shift in exposure to fluvial and tidal flooding, particularly attributed to the working age population. This highlights the improvements achievable to flood risk management as well as potential application to other natural hazard scenarios both within the UK and globally

Using the Java Media Framework to build Adaptive Groupware Applications

Realtime audio and video conferencing has not yet been satisfactorily integrated into web-based groupware environments. Conferencing tools are at best only loosely linked to other parts of a shared working environment, and this is in part due to their implications for resource allocation and management. The Java Media Framework offers a promising means of redressing this situation. This paper describes an architecture for integrating the management of video and audio conferences into the resource allocation mechanism of an existing web-based groupware framework. The issue of adaptation is discussed and a means of initialising multimedia session parameters based on predicted QoS is described

Inventory Fluctuations, Temporary Layoffs and the Business Cycle

Firms respond to fluctuations in demand by changing their inventories and their levels of production. The relative magnitudes of the inventory and production responses have important implications for the overall cyclical behavior of the economy. Government policies that affect the costs of holding inventories and the costs of the temporary layoffs that accompany reductions in the level of output can therefore have significant effects on the magnitude of aggregate fluctuations. The current paper presents new econometric evidence on the nature of inventory adjustments and then examines how changes in inventory behavior affect the overall business cycle. The analysis in this paper was motivated by our discovery that the parameter estimates of the traditional productional adjustment model are not consistent with the observed magnitudes of inventory change and the production. We have shown here that this production adjustment model is a special case of a more general two-speed adjustment process in which both production and inventory targets adjust slowly. Our estimates of the two-speed model clearly reject the production adjustment model in favor of the target adjustment model in which the inventory target adjusts slowly to changes in sales but production adjusts rapidly to changes in the desired inventory. Our analysis of the spectral properties of a simple macroeconomic model show that the production adjustment model and the target adjustment model can imply quite different cyclical behavior of the economy as a whole. Depending on the autocorrelation of the disturbance, government policies that reduce the speed with which production responds to changes in desired inventories and that place greater reliance on inventory adjustment may stabilize national income. Further analysis of these questions with more realistic models would clearly be desirable.