Bayesian updating of atmospheric dispersion after a nuclear accident

Summary.  We consider a Bayesian forecasting system to predict the dispersal of contamination on a large scale grid in the event of an accidental release of radioactivity. The statistical model is built on a physical model for atmospheric dispersion and transport called MATCH. Our spatiotemporal model is a dynamic linear model where the state parameters are the (essentially, deterministic) predictions of MATCH; the distributions of these are updated sequentially in the light of monitoring data. One of the distinguishing features of the model is that the number of these parameters is very large (typically several hundreds of thousands) and we discuss practical issues arising in its implementation as a realtime model. Our procedures have been checked against a variational approach which is used widely in the atmospheric sciences. The results of the model are applied to test data from a tracer experiment.     

A circular-cone test for testing homogeneity against a simple tree order

Several methods exist for the problem of testing the equality of several treatments against the one-sided alternative that the treatments are better than the control. These methods include Dunnett's test, Bartholomew's likelihood-ratio test, the Abelson-Tukey-Schaafsma-Smid optimal-contrast test, and the multiple-contrast test of Mukerjee, Robertson, and Wright. A new test is proposed based on an approximation of the likelihood-ratio test of Bartholomew. This test involves using a circular cone in place of the alternative-hypothesis cone. The circular-cone test has excellent power characteristics similar to those of Bartholomew's test. Moreover, it has the advantages of being simpler to compute and may be used with unequal sample sizes.     

Access to Water in the Slums of Sub‐Saharan Africa

This article reviews the changing perspectives for improving access to water in the slums of developing countries, especially in sub‐Saharan Africa. While much of the literature continues to maintain an aversion to state‐led urban development policies, there is now increasing emphasis on the importance of informal, small‐scale providers and communitarian initiatives, following the many failures of privatisation. The article argues that market‐oriented solutions are inappropriate for sub‐Saharan African countries where over two‐thirds of the urban population live in squatter settlements with multidimensional challenges.     

A reflected feature space for CART

We present an algorithm for learning oblique decision trees, called HHCART(G). Our decision tree combines learning concepts from two classification trees, HHCART and Geometric Decision Tree (GDT). HHCART(G) is a simplified HHCART algorithm that uses linear structure in the training examples, captured by a modified GDT angle bisector, to define splitting directions. At each node, we reflect the training examples with respect to the modified angle bisector to align this linear structure with the coordinate axes. Searching axis parallel splits in this reflected feature space provides an efficient and effective way of finding oblique splits in the original feature space. Our method is much simpler than HHCART because it only considers one reflected feature space for node splitting. HHCART considers multiple reflected feature spaces for node splitting making it more computationally intensive to build. Experimental results show that HHCART(G) is an effective classifier, producing compact trees with similar or better results than several other decision trees, including GDT and HHCART trees.     

Replica localization in East Asia: the case of the Asian hedge fund industry

Hedge funds exemplify complex finance in the global economy and are appearing in diverse national settings. One question that follows is whether hedge funds in the Asian region have been localized and exhibit significant differences to their US/UK counterparts or whether there is predominantly one global model. The analysis here point to the importance of what is called replica localization, wherein local control has entailed little deviation from the practices of Anglo-American hedge funds. Evidence generated from databases and interviews confirms the largely equivalent structures and strategies found in the new Asian hedge fund sector. The significance is that a small but growing Asian financial space has been carved out that is funded by Asian capital and managed by Asian elites but matches external models. To further delineate globalized finance, comparative research is needed to determine when and why complex finance is either present or absent outside of Anglo-American economies.     

Short Break and Respite Services for Disabled Children in England: Comparing Children's and Parents' Perspectives of Their Impact on Children

Researchers, health and social care workers often seek to understand the perspectives of children; but gathering views directly from children can present difficulties. Parents are often asked to provide accounts of children's feelings or opinions on the assumption that their proxy reports are accurate and unproblematic. This qualitative thematic analysis of open‐question responses from 352 parents and 73 disabled children examines their accounts of the impact of short break services on disabled children. Participants' perspectives differed; children tended to describe immediate outcomes such as enjoying activities and participation; parents acknowledged these, but focused on longer term developmental outcomes for children.     

Diffusion in the Face of Failure: The Evolution of a Management Innovation

Recent work has questioned the institutional model of management innovation by highlighting interactions between the field‐level actors engaged in diffusing innovations and implementation of the innovation at organization level. Focusing on the adaptation of management innovations to their context, rather than their creation, we review this work and use it to analyse the global diffusion of resource planning (RP), counter posing this case with the widely studied example of total quality management. Both of these innovations experienced a high level of failure when implemented by organizations. Total quality management's diffusion was characterized by a ‘boom and bust’ cycle. RP, however, has continued to spread globally in the form of its variants: MRP, MRPII and ERP. Our analysis seeks to account for the long‐run diffusion of RP through a processual model which highlights the interplay between RP's discursive framing at field level, the affordances of the innovation itself and its adaptation within organizations. This demonstrates how objectifying RP in software not only helped to spread the innovation but also allowed field‐level actors to differentiate its development as a successful innovation from the many failures experienced by organizations attempting to adapt it.     

Microforms

Abstract

The editors scan approximately 140 journals in all disciplines for reviews of serial publications. Journals published since January 2000 were monitored for this installment of Serials Review Index. Suggestions for journals to be included in future columns are welcome. Serials Review 2002; 28:57–62.