title: Inducing cost-sensitive trees via instance-weighting

authors: Ting, Kai Ming

subjects: Cost-sensitive trees

abstract: We introduce an instance-weighting method to induce cost-sensitive trees in this paper. It is a generalization of the standard tree induction process where only the initial instance weights determine the type of tree (i.e., minimum error trees or minimum cost trees) to be induced. We demonstrate that it can be easily adopted to an existing tree learning algorithm. 
Previous research gave insufficient evidence to support the fact that the greedy divide-and-conquer algorithm can effectively induce a truly cost-sensitive tree directly from the training data. We provide this empirical evidence in this paper. The algorithm employing the instance-weighting method is found to be comparable to or better than both C4.5 and C5 in terms of total misclassification costs, tree size and the number of high cost errors. The instance-weighting method is also simpler and more effective in implementation than a method based on altered priors.

text: Inducing cost-sensitive trees via instance-weighting We introduce an instance-weighting method to induce cost-sensitive trees in this paper. It is a generalization of the standard tree induction process where only the initial instance weights determine the type of tree (i.e., minimum error trees or minimum cost trees) to be induced. We demonstrate that it can be easily adopted to an existing tree learning algorithm. 
Previous research gave insufficient evidence to support the fact that the greedy divide-and-conquer algorithm can effectively induce a truly cost-sensitive tree directly from the training data. We provide this empirical evidence in this paper. The algorithm employing the instance-weighting method is found to be comparable to or better than both C4.5 and C5 in terms of total misclassification costs, tree size and the number of high cost errors. The instance-weighting method is also simpler and more effective in implementation than a method based on altered priors.

year: 1997-09

title: Co-contaminants and factors affecting the sorption behaviour of two sulfonamides in pasture soils

authors: Srinivasan, Prakash

subjects: veterinary antibiotics

abstract: We investigated the effect of soil pH, organic carbon, ionic strength and steroid hormones on the sorption of sulfamethoxazole (SMO) and sulfachloropyridazine (SCP) in three pastoral soils of New Zealand. A model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was used to derive the fraction of each species of SMO. All soils displayed a decrease in sorption when pH was increased, with SMO exhibiting the highest sorption at pH 2. The cationic form of SMO appeared to sorb more close to pH ≥ pKa1 and, when pH ≥ pKa2 (6.5, 7.5 and 8.5) the anionic species seems to dominate, however, its sorption affinity to all soils was low. SMO sorption was affected by ionic strengths and organic carbon content, while the presence of hormones showed only a subtle decrease in SCP sorption in a selected model pasture soil.

text: Co-contaminants and factors affecting the sorption behaviour of two sulfonamides in pasture soils We investigated the effect of soil pH, organic carbon, ionic strength and steroid hormones on the sorption of sulfamethoxazole (SMO) and sulfachloropyridazine (SCP) in three pastoral soils of New Zealand. A model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was used to derive the fraction of each species of SMO. All soils displayed a decrease in sorption when pH was increased, with SMO exhibiting the highest sorption at pH 2. The cationic form of SMO appeared to sorb more close to pH ≥ pKa1 and, when pH ≥ pKa2 (6.5, 7.5 and 8.5) the anionic species seems to dominate, however, its sorption affinity to all soils was low. SMO sorption was affected by ionic strengths and organic carbon content, while the presence of hormones showed only a subtle decrease in SCP sorption in a selected model pasture soil.

year: 2013

title: Inter-propositional semantic relations and semantic relational encoding in written discourse in Maori: an investigation

authors: Houia, Waldo

subjects: Maori

abstract: This thesis is an investigation of the various ways in which relationships of meaning between propositions (such as reason-result and temporal overlap) are encoded (as clauses, sentences and groups of sentences) and signalled in Maori.
In Chapter 1, the overall research topic and research questions are outlined.
Chapter 2 locates the research on inter-propositional semantic relations with reference to the concept of cohesion which is central to inter-propositional relational signalling and encoding. Here, reference is made to a number of relevant publications in the area.
Chapter 3 provides an introductory examination of the role of cohesion in the encoding and signalling of inter-propositional semantic relations in Maori.
Chapter 4 introduces a corpus of written texts and examines that corpus in terms of the ways in which inter-propositional semantic relations are encoded.
Chapter 5 examines a number of textbooks designed for learners of both English and Maori in terms of the extent to which they draw upon insights relating to the operation of inter-propositional semantic relations.
In Chapter 6, the research findings are summarised and their implications for aspects of the teaching and learning of Maori are discussed. In addition, suggestions are made in relation to future research possibilities.
Overall, the conclusion reached is that the study of semantic relational encoding and signalling in Maori texts reveals a number of aspects of language that appear not to be commonly taught and suggests the need for further studies of this type.

text: Inter-propositional semantic relations and semantic relational encoding in written discourse in Maori: an investigation This thesis is an investigation of the various ways in which relationships of meaning between propositions (such as reason-result and temporal overlap) are encoded (as clauses, sentences and groups of sentences) and signalled in Maori.
In Chapter 1, the overall research topic and research questions are outlined.
Chapter 2 locates the research on inter-propositional semantic relations with reference to the concept of cohesion which is central to inter-propositional relational signalling and encoding. Here, reference is made to a number of relevant publications in the area.
Chapter 3 provides an introductory examination of the role of cohesion in the encoding and signalling of inter-propositional semantic relations in Maori.
Chapter 4 introduces a corpus of written texts and examines that corpus in terms of the ways in which inter-propositional semantic relations are encoded.
Chapter 5 examines a number of textbooks designed for learners of both English and Maori in terms of the extent to which they draw upon insights relating to the operation of inter-propositional semantic relations.
In Chapter 6, the research findings are summarised and their implications for aspects of the teaching and learning of Maori are discussed. In addition, suggestions are made in relation to future research possibilities.
Overall, the conclusion reached is that the study of semantic relational encoding and signalling in Maori texts reveals a number of aspects of language that appear not to be commonly taught and suggests the need for further studies of this type.

year: 2001