Exploring systems interactions for building resilience within coastal environments and communities.

This paper focuses on identifying examples of first-order systems interactions, which make important contributions to building coastal resiliency for coastal zone management. This discussion is based on an application of the Institutional Analysis and Development Framework to a case-study analysis of coastal management in South Australia. The study suggests that cross-scale interactions and informal relationships within and between users and managers are key interactions defining resilience outcomes within the current system. A significant constraint on improving resilience was the lack of evaluative criteria for identifying sustainable forms of system behaviour. The paper argues that resilience is a function of a normative statement on the characteristics desirable in the functioning system. Analyses of coastal resilience, which facilitate greater understanding of the range of complexities in coastal behaviour, are therefore central to gaining the most useful insights into the options and pathways for building more sustainable coastal futures

On ordinal utility, cardinal utility, and random utility

Though the Random Utility Model (RUM) was conceived  entirely in terms of ordinal utility, the apparatus throughwhich it is widely practised exhibits properties of  cardinal utility.  The adoption of cardinal utility as a  working operation of ordinal is perfectly valid, provided  interpretations drawn from that operation remain faithful  to ordinal utility.  The paper considers whether the latterrequirement holds true for several measurements commonly  derived from RUM.  In particular it is found that  measurements of consumer surplus change may depart from  ordinal utility, and exploit the cardinality inherent in  the practical apparatus.

Sparse Graph Codes for Quantum Error-Correction

We present sparse graph codes appropriate for use in quantum error-correction. Quantum error-correcting codes based on sparse graphs are of interest for three reasons. First, the best codes currently known for classical channels are based on sparse graphs. Second, sparse graph codes keep the number of quantum interactions associated with the quantum error correction process small: a constant number per quantum bit, independent of the blocklength. Third, sparse graph codes often offer great flexibility with respect to blocklength and rate. We believe some of the codes we present are unsurpassed by previously published quantum error-correcting codes.Comment: Version 7.3e: 42 pages. Extended version, Feb 2004. A shortened version was resubmitted to IEEE Transactions on Information Theory Jan 20, 200

Solution of a Braneworld Big Crunch/Big Bang Cosmology

We solve for the cosmological perturbations in a five-dimensional background consisting of two separating or colliding boundary branes, as an expansion in the collision speed V divided by the speed of light c. Our solution permits a detailed check of the validity of four-dimensional effective theory in the vicinity of the event corresponding to the big crunch/big bang singularity. We show that the four-dimensional description fails at the first nontrivial order in (V/c)^2. At this order, there is nontrivial mixing of the two relevant four-dimensional perturbation modes (the growing and decaying modes) as the boundary branes move from the narrowly-separated limit described by Kaluza-Klein theory to the well-separated limit where gravity is confined to the positive-tension brane. We comment on the cosmological significance of the result and compute other quantities of interest in five-dimensional cosmological scenarios.Comment: 54 pages, 12 figures, URL updated & 3 references adde

An overview of palaeomagnetic chronology with special reference to the South African hominid sites

Main articleThe phenomena of secular variation, polarity reversals and apparent polar wander are discussed. The calibration of each of these phenomena for use in palaeomagnetic chronology is outlined and the use of each of these calibrated scales for dating is briefly explained. A successful application of the polarity reversal dating technique is presented as an example of the potential for palaeomagnetic chronology in South Africa. In this example it is shown that the age of the important Member 3 in Makapan is about 3 My. It is concluded that palaeomagnetic chronology has a vast potential in South Africa ; a palaeomagnetic laboratory specifically oriented to chronological problems would be extremely valuable.Non