Likelihood estimators for multivariate extremes

The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model

Youth Justice and Education: A Typology of Educational Approaches to the Resocialisation of Young Offenders in Spain

The Young Offenders Act that entered Spanish law in 2000 represents a significant attempt to place personalised educational programmes for young people with social/criminal problems at the centre of policy and practice. This paper examines the teams and educational programmes designed to manage and implement the goal of ?re-socialisation? enshrined in the Act. This paper focuses on an analytical typology of the educational styles used at young offenders institutions in Spain. The analysis highlights the differences between styles in relation to the key underlying objectives of social reorientation and citizen empowerment. The wide range of models experimented with in different Spanish regions has great relevance to youth justice systems in other countries. For example, the typology we put forward has concrete implications for recent developments in England, in the light of moves towards establishing a national network of ?Secure Colleges? for convicted young people

Delivering social housing: examining the nexus between social housing and democratic planning

The construction of social housing in gentrifying neighbourhoods can ignite contestation, revealing tensions between economic imperatives, social policy and neighbourhood change. With a view to understanding how the convergence of these agendas preserve unpopular, but socially critical housing infrastructure, the aim of this paper is to explore how the challenges social housing implementation encounters across these agendas intersect with a broader agenda for local democratic planning. Using social housing as our empirical focus and directing attention to the gentrifying local government area of Port Phillip in Victoria, Australia, this paper reveals how a council's main asset to support implementation - its policy frameworks - creates an urban narrative of social inclusivity and diversity. Through this case, we illustrate how elected officials and some residents draw from these policies to interject into episodes of community contestation, which we argue presents opportunities to expose and renew commitments to social housing over space and time

Interpreting intraplate tectonics for seismic hazard : a UK historical perspective

It is notoriously difficult to construct seismic source models for probabilistic seismic hazard assessment in intraplate areas on the basis of geological information, and many practitioners have given up the task in favour of purely seismicity-based models. This risks losing potentially valuable information in regions where the earthquake catalogue is short compared to the seismic cycle. It is interesting to survey how attitudes to this issue have evolved over the past 30 years. This paper takes the UK as an example, and traces the evolution of seismic source models through generations of hazard studies. It is found that in the UK, while the earliest studies did not consider regional tectonics in any way, there has been a gradual evolution towards more tectonically based models. Experience in other countries, of course, may differ

Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden.

BACKGROUND: We have conducted a population-based study of pleural mesothelioma patients with occupational histories and measured asbestos lung burdens in occupationally exposed workers and in the general population. The relationship between lung burden and risk, particularly at environmental exposure levels, will enable future mesothelioma rates in people born after 1965 who never installed asbestos to be predicted from their asbestos lung burdens. METHODS: Following personal interview asbestos fibres longer than 5 µm were counted by transmission electron microscopy in lung samples obtained from 133 patients with mesothelioma and 262 patients with lung cancer. ORs for mesothelioma were converted to lifetime risks. RESULTS: Lifetime mesothelioma risk is approximately 0.02% per 1000 amphibole fibres per gram of dry lung tissue over a more than 100-fold range, from 1 to 4 in the most heavily exposed building workers to less than 1 in 500 in most of the population. The asbestos fibres counted were amosite (75%), crocidolite (18%), other amphiboles (5%) and chrysotile (2%). CONCLUSIONS: The approximate linearity of the dose-response together with lung burden measurements in younger people will provide reasonably reliable predictions of future mesothelioma rates in those born since 1965 whose risks cannot yet be seen in national rates. Burdens in those born more recently will indicate the continuing occupational and environmental hazards under current asbestos control regulations. Our results confirm the major contribution of amosite to UK mesothelioma incidence and the substantial contribution of non-occupational exposure, particularly in women

Empirical supremum rejection sampling

Rejection sampling thins out samples from a candidate density from which it is easy to simulate, to obtain samples from a more awkward target density. A prerequisite is knowledge of the finite supremum of the ratio of the target and candidate densities. This severely restricts application of the method because it can be difficult to calculate the supremum. We use theoretical argument and numerical work to show that a practically perfect sample may be obtained by replacing the exact supremum with the maximum obtained from simulated candidates. We also provide diagnostics for failure of the method caused by a bad choice of candidate distribution. The implication is that essentially no theoretical work is required to apply rejection sampling in many practical case

Test Station for a 30 m long Superconducting Link

The Large Hadron Collider (LHC) requires distribution of high electrical currents in the limited space of LHC tunnel. Four superconducting links of about 76 m length and one of 510 m will be installed in the tunnel to carry 6 kA and 600 A. For validation of the longest link a test station was designed which is presently under construction. The design will permit the test station to be adapted for other links and/or cables as well. It will operate either in pool boiling mode, in order to measure thermal loads, or in forced super-critical helium flow mode to simulate real operation. Inlet pressure is 1.2 bar to 3 bar. Inlet temperature is adjustable from 4.4 K up to about 20 K. The station is being prepared to validate the LHC model link, consisting of 48 superconducting cables, each operating at 600 A between 4.5 K and 5.4 K. This article describes features of the equipment