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Conventional wisdom provides an increasingly strong endorsement of far-reaching decentralization and delegation of authority to bureaucratic agents as the most likely mechanisms to attain such central environmental policy goals as pollution prevention, cross-media regulatory integration, and development of reliable measures of environmental outcomes. Canada would appear an unusually fertile context for such Innovation, given its far-reaching deference to individual provinces and their environment ministries in environmental policy. Comparative analysis of select sub national governments in Canada and the United States suggests that the states in general are far ahead of their provincial counterparts in most of these areas of innovation. Despite all the opprobrium heaped on the American environmental policy system, a combination of federal policy tools and state policy entrepreneur ship appear to contribute directly to this innovation in some states and are almost completely absent in the Canadian system. These findings suggest a need for careful study of the mix of intergovernmental policy tools and principal-agent relations most likely to realize desired environmental policy goals.  相似文献   
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The ‘street’ and ‘youth’ have long been issues of social concern and the subject of research both in Brazil and elsewhere. The perception and experiences of youth in relation to the street, however, and the corresponding gender and class relations which permeate these, remain an under-researched topic. Drawing on fieldwork conducted in low- and middle-income neighbourhoods in Recife, this paper shows how the street consists of different spaces and how the youth experience corresponding layers of socio-spatial exclusions and inclusions which vary over time.  相似文献   
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This article presents a new spatial modeling approach that deals with interactions between individual geographic entities. The developed model represents a generalization of the transportation problem and the classical assignment problem and is termed the hierarchical assignment problem (HAP). The HAP optimizes the spatial flow pattern between individual origin and destination locations, given that some grouping, or aggregation of individual origins and destinations is permitted to occur. The level of aggregation is user specified, and the aggregation step is endogenous to the model itself. This allows for the direct accounting of aggregation costs in pursuit of optimal problem solutions. The HAP is formulated and solved with several sample data sets using commercial optimization software. Trials illustrate how HAP solutions respond to changes in levels of aggregation, as well as reveal the diverse network designs and allocation schemes obtainable with the HAP. Connections between the HAP and the literature on the p-median problem, cluster analysis, and hub-and-spoke networks are discussed and suggestions for future research are made.  相似文献   
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The desire of many geographical information science (GIS) practitioners to undertake sophisticated spatial pattern analysis has been facilitated by the increasing availability of specialised software and the appearance of pedagogic papers illustrating the application of various techniques. However, the appropriate use of these techniques also requires an understanding of the nature of hypothesis testing and statistical inference for spatial data. Since there is little information currently available to aid the GIS practitioner in this regard, we offer such guidance here. We do so by revisiting the steps involved in spatial pattern analysis. Our perspective is based on the notion of spatial stochastic models and is presented as a decision tree. The four levels of the tree (i.e., sequential decisions) are associated with the assumptions, the type of data representation and the types of questions asked by the analyst. We emphasise the scientific and educational challenges involved.  相似文献   
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The participation of children and young people in decisions that affect them is now mainstream in social and public policy in the UK. Yet for many young people formal participation opportunities are abstracted from everyday lives and concerns. Children may not feel empowered despite the existence of formal structures for participation. This raises questions about how ‘spaces’ for participation are constructed. This paper critiques prevailing models of participation in formal structures and instead, argues for the need to rethink children's participation as a more diverse set of social processes rooted in everyday environments and interactions.  相似文献   
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