title: Boosting trees for cost-sensitive classifications

authors: Ting, Kai Ming

subjects: computer science

abstract: This paper explores two boosting techniques for cost-sensitive tree classification in the situation where misclassification costs change very often. Ideally, one would like to have only one induction, and use the induced model for different misclassification costs. Thus, it demands robustness of the induced model against cost changes. Combining multiple trees gives robust predictions against this change. We demonstrate that ordinary boosting combined with the minimum expected cost criterion to select the prediction class is a good solution under this situation. We also introduce a variant of the ordinary boosting procedure which utilizes the cost information during training. We show that the proposed technique performs better than the ordinary boosting in terms of misclassification cost. However, this technique requires to induce a set of new trees every time the cost changes. Our empirical investigation also reveals some interesting behavior of boosting decision trees for cost-sensitive classification.

text: Boosting trees for cost-sensitive classifications This paper explores two boosting techniques for cost-sensitive tree classification in the situation where misclassification costs change very often. Ideally, one would like to have only one induction, and use the induced model for different misclassification costs. Thus, it demands robustness of the induced model against cost changes. Combining multiple trees gives robust predictions against this change. We demonstrate that ordinary boosting combined with the minimum expected cost criterion to select the prediction class is a good solution under this situation. We also introduce a variant of the ordinary boosting procedure which utilizes the cost information during training. We show that the proposed technique performs better than the ordinary boosting in terms of misclassification cost. However, this technique requires to induce a set of new trees every time the cost changes. Our empirical investigation also reveals some interesting behavior of boosting decision trees for cost-sensitive classification.

year: 1998-01

title: Sustainability, governance and water management in New Zealand

authors: Daya-Winterbottom, Trevor

abstract: New Zealand is a “pluvial society”.The common perception before 1997 was that there were no serious issues regarding freshwater in New Zealand compared with other jurisdictions, notwithstanding the fact that irrigation had doubled to 500,000ha during the period 1985 to 1997. However, freshwater allocation was set to become a significant issue in the future. By 2003 problems in the Waitaki catchment of the South Island brought matters sharply into focus as competition between productive users became fierce and increasingly litigious, and problems were occuring regarding allocation between competing irrigation applications and between irrigation and hydro electric power schemes. 
Subsequently, freshwater allocation has been subject to legislative amendments and litigation before the Supreme Court, and new planning documents at both national and regional level are being developed to guide decision making. Demand for freshwater use has continued to grow “to the point [in many areas] where shortages occur because the spatial and temporal patterns of supply do not match demand patterns”, and it is expected that “the majority of the catchments that support New Zealand’s main population centres and agricultural production … [will] be fully allocated by 2012”.  
The purpose of this paper is to review the law on restrictions relating to freshwater under the Resource Management Act 1991 (RMA). The paper will focus on the taking and use of water, and current proposals for reform of the water management regime under the RMA.

text: Sustainability, governance and water management in New Zealand New Zealand is a “pluvial society”.The common perception before 1997 was that there were no serious issues regarding freshwater in New Zealand compared with other jurisdictions, notwithstanding the fact that irrigation had doubled to 500,000ha during the period 1985 to 1997. However, freshwater allocation was set to become a significant issue in the future. By 2003 problems in the Waitaki catchment of the South Island brought matters sharply into focus as competition between productive users became fierce and increasingly litigious, and problems were occuring regarding allocation between competing irrigation applications and between irrigation and hydro electric power schemes. 
Subsequently, freshwater allocation has been subject to legislative amendments and litigation before the Supreme Court, and new planning documents at both national and regional level are being developed to guide decision making. Demand for freshwater use has continued to grow “to the point [in many areas] where shortages occur because the spatial and temporal patterns of supply do not match demand patterns”, and it is expected that “the majority of the catchments that support New Zealand’s main population centres and agricultural production … [will] be fully allocated by 2012”.  
The purpose of this paper is to review the law on restrictions relating to freshwater under the Resource Management Act 1991 (RMA). The paper will focus on the taking and use of water, and current proposals for reform of the water management regime under the RMA.

year: 2011

title: Poster Abstracts

authors: Lapsley, Hilary

subjects: Maori

abstract: These are the poster abstracts from the Proceedings of the National Māori Graduates of Psychology Symposium 2002.

text: Poster Abstracts These are the poster abstracts from the Proceedings of the National Māori Graduates of Psychology Symposium 2002.

year: 2003