An MDL approach to the climate segmentation problem

This paper proposes an information theory approach to estimate the number of changepoints and their locations in a climatic time series. A model is introduced that has an unknown number of changepoints and allows for series autocorrelations, periodic dynamics, and a mean shift at each changepoint time. An objective function gauging the number of changepoints and their locations, based on a minimum description length (MDL) information criterion, is derived. A genetic algorithm is then developed to optimize the objective function. The methods are applied in the analysis of a century of monthly temperatures from Tuscaloosa, Alabama.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS289 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Latent Gaussian Count Time Series Modeling

This paper develops theory and methods for the copula modeling of stationary count time series. The techniques use a latent Gaussian process and a distributional transformation to construct stationary series with very flexible correlation features that can have any pre-specified marginal distribution, including the classical Poisson, generalized Poisson, negative binomial, and binomial count structures. A Gaussian pseudo-likelihood estimation paradigm, based only on the mean and autocovariance function of the count series, is developed via some new Hermite expansions. Particle filtering methods are studied to approximate the true likelihood of the count series. Here, connections to hidden Markov models and other copula likelihood approximations are made. The efficacy of the approach is demonstrated and the methods are used to analyze a count series containing the annual number of no-hitter baseball games pitched in major league baseball since 1893

Trends in Extreme U.S. Temperatures

This paper develops trend estimation techniques for monthly maximum and minimum temperature time series observed in the 48 conterminous United States over the last century. While most scientists concur that this region has warmed on aggregate, there is no a priori reason to believe that temporal trends in extremes and averages will exhibit the same patterns. Indeed, under minor regularity conditions, the sample partial sum and maximum of stationary time series are asymptotically independent (statistically). Previous authors have suggested that minimum temperatures are warming faster than maximum temperatures in the United States; such an aspect can be investigated via the methods discussed in this study. Here, statistical models with extreme value and changepoint features are used to estimate trends and their standard errors. A spatial smoothing is then done to extract general structure. The results show that monthly maximum temperatures are not often greatly changing—perhaps surprisingly, there are many stations that show some cooling. In contrast, the minimum temperatures show significant warming. Overall, the southeastern United States shows the least warming (even some cooling), and the western United States, northern Midwest, and New England have experienced the most warming

Confidence Intervals for Long Memory Regressions

This paper proposes an accurate confidence interval for the trend parameter in a linear regression model with long memory errors. The interval is based upon an equivalent sum of squares method and is shown to perform comparably to a weighted least squares interval. The advantages of the proposed interval lies in its relative ease of computation and should be attractive to practitioners

Lawrence v. Texas and Judicial Hubris

Lawrence v. Texas produces a desirable policy result, but it deserves condemnation as a legal decision. It repudiates the Supreme Court\u27s most recent attempt to put doctrinal restraints on the most anticonstitutional doctrine in constitutional law - substantive due process. That doctrine, for which the Court has never provided a successful textual justification, has been selectively employed over the decades to advance a variety of political agendas popular with Supreme Court majorities. In 1938, Carolene Products put meaningful restraints on substantive due process, taming that doctrine for about a quarter of a century. With Griswold and Roe v. Wade, the Court adopted a new substantive due process agenda - sexual freedom. In Washington v. Glucksberg, the Court sought to restore most of the limits of the Carolene Products approach, while leaving the Griswold-Roe line in place, by adopting a test requiring that newly recognized rights be deeply rooted in the nation\u27s history and tradition. Lawrence repudiates the Glucksberg approach and instead deploys an undisciplined form of judicial mysticism. Notwithstanding the availability of plausible arguments based on precedent to invalidate the Texas law, the Lawrence Court chose instead to rely on a series of utterly untenable arguments and analytically empty bombast. We argue that the Lawrence approach is not law in any meaningful sense of the term, but only a vehicle for judges to impose their own political preferences on the nation. We also rebut some justifications that could be offered in defense of Lawrence. We show that Professor Robert Post\u27s concept of a conversation between the Court and the nation obliterates the concept of law as something distinct from politics, and offers a theory of judicial review that would justify even a decision like Plessy v. Ferguson. Second, we show that Professor Randy Barnett fails in his effort to provide Lawrence with a foundation in the Constitution because he misinterprets the Ninth Amendment and the Privileges or Immunities Clause. Third, we rebut those who would defend Lawrence on pragmatic grounds by explaining why we think competitive federalism is a far superior mechanism for creating new norms of liberty, and for correcting the mistakes that are inevitable in any process of policy development. Finally, we outline the case for repudiating the Griswold-Roe-Lawrence line of cases and for using the Glucksberg test to return the Court\u27s substantive due process jurisprudence roughly to where it stood as a result of Carolene Products

A preliminary study of the potential for recycling and waste minimisation at Edith Cowan University: report to the Edith Cowan University Student Guild

In recent years there has been a growing realisation worldwide that disposing of large quantities of waste to landfill was not only causing problems of pollution(e.g. leachate and gas production) but suitable sites were rapidly filling up. In Perth it is has been estimated that present landfill sites will only last until 2007 (Sinclair and Knight, 1991). To help extend the life of current landfill sites and in response to environmental concerns the Western . Australia Government produced a State Recycling Blueprint (Department of Commerce and Trade, 1993). This describes strategies for the minimisation of waste production and maximisation of recycling and reuse. A majority of local shire councils have started kerbside recycling schemes, where the increased· cost of collection and sorting is offset against reductions in landfill waste and the sale of recyclable materials. As the universities are not ratable properties they are not covered by council recycling schemes (although both Wanneroo and Stirling City Councils will pick up recyclables, without reward). Universities are by most standards large producers of waste. To discard most of this waste for disposal to landfill is becoming increasingly unacceptable to many in the community: Curtin University has recently introduced a recycling initiative and it is likely that the other WA universities will follow suit Curtin. managed to attract considerable favourable publicity during the introduction of it\u27s initiative. The willingness· of the Student Guild of Edith Cowan University (ECU) to fund this study indicates that there. is the potential for a recycling initiative at ECU to be successful