title: Pairwise meta-rules for better meta-learning-based algorithm ranking

authors: Sun, Quan

subjects: meta-learning

abstract: In this paper, we present a novel meta-feature generation method in the context of meta-learning, which is based on rules that compare the performance of individual base learners in a one-against-one manner. In addition to these new meta-features, we also introduce a new meta-learner called Approximate Ranking Tree Forests (ART Forests) that performs very competitively when compared with several state-of-the-art meta-learners. Our experimental results are based on a large collection of datasets and show that the proposed new techniques can improve the overall performance of meta-learning for algorithm ranking significantly. A key point in our approach is that each performance figure of any base learner for any specific dataset is generated by optimising the parameters of the base learner separately for each dataset.

text: Pairwise meta-rules for better meta-learning-based algorithm ranking In this paper, we present a novel meta-feature generation method in the context of meta-learning, which is based on rules that compare the performance of individual base learners in a one-against-one manner. In addition to these new meta-features, we also introduce a new meta-learner called Approximate Ranking Tree Forests (ART Forests) that performs very competitively when compared with several state-of-the-art meta-learners. Our experimental results are based on a large collection of datasets and show that the proposed new techniques can improve the overall performance of meta-learning for algorithm ranking significantly. A key point in our approach is that each performance figure of any base learner for any specific dataset is generated by optimising the parameters of the base learner separately for each dataset.

year: 2013-07

title: MHD turbulence and heating of the open field-line solar corona

authors: Matthaeus, William H.

subjects: magnetohydrodynamics (MHD)

abstract: This paper discusses the possibility that heating of the solar corona in open field-line regions emanating from coronal holes is due to a nonlinear cascade, driven by low-frequency or quasi-static magnetohydrodynamic fluctuations. Reflection from coronal inhomogeneities plays an important role in sustaining the cascade. Physical and observational constraints are discussed. Kinetic processes that convert cascaded energy into heat must occur in regions of turbulent small-scale reconnection, and may be similar in some respects to ion heating due to intense electron beams observed in the aurora.

text: MHD turbulence and heating of the open field-line solar corona This paper discusses the possibility that heating of the solar corona in open field-line regions emanating from coronal holes is due to a nonlinear cascade, driven by low-frequency or quasi-static magnetohydrodynamic fluctuations. Reflection from coronal inhomogeneities plays an important role in sustaining the cascade. Physical and observational constraints are discussed. Kinetic processes that convert cascaded energy into heat must occur in regions of turbulent small-scale reconnection, and may be similar in some respects to ion heating due to intense electron beams observed in the aurora.

year: 2003

title: Utuhina Stream 2006-2020: In-stream alum dosing effects on fish and aquatic invertebrates

authors: Ling, Nicholas

abstract: This report presents the results of an on-going assessment of the fish and aquatic macroinvertebrate communities of the Utuhina Stream, Lake Rotorua, from 2006 to 2020, and an assessment of the bioavailability of aluminium in fish and kōura to satisfy Bay of Plenty Regional Council’s annual resource consent conditions 9.6, 9.8 and 9.7, respectively, for consent 65321 for the discharge of alum to the Utuhina Stream. Macroinvertebrates, fish and kōura (freshwater crayfish) were sampled from one control and two treatment reaches of the Utuhina Stream annually. Common bully (Gobiomorphus cotidianus) is the dominant species in the fish community of the Utuhina Stream. Kōura (Paranephrops planifrons) and juvenile trout were always present at all sites but variable in abundance. Differences in species abundance from year to year are most likely due to flood-related disturbances to stream bank morphology and in-stream vegetative cover or physical displacement of fish. No obvious effects of alum dosing on stream fish or macroinvertebrate communities were observed between the upstream control site and sites downstream of the alum discharge. Several other fish species were occasionally captured during sampling and the regular occurrence of juvenile koaro from 2016 to 2019 is possible evidence of this taonga species becoming established in the Utuhina. Analysis of stream macroinvertebrates also showed no consistent differences between the upstream control site and the sites downstream of the alum dosing. Overall, all sites were characterised as fair to good quality for a soft-bottomed stream. Some evidence of aluminium bioaccumulation was seen in some tissues of common bully (gills and liver) in some years, resulting from continuous alum dosing of the Utuhina Stream, but there was no evidence of bioaccumulation of aluminium in the tissues of kōura. Alum exposure in these species does not appear to affect their health or abundance in the stream.   iii Overall, continuous alum discharge does not appear to negatively impact the ecology of the lower Utuhina and improvements in the ecological condition of the Utuhina Stream will be achieved by ongoing riparian restoration and mitigation of the impacts of flood flows.

text: Utuhina Stream 2006-2020: In-stream alum dosing effects on fish and aquatic invertebrates This report presents the results of an on-going assessment of the fish and aquatic macroinvertebrate communities of the Utuhina Stream, Lake Rotorua, from 2006 to 2020, and an assessment of the bioavailability of aluminium in fish and kōura to satisfy Bay of Plenty Regional Council’s annual resource consent conditions 9.6, 9.8 and 9.7, respectively, for consent 65321 for the discharge of alum to the Utuhina Stream. Macroinvertebrates, fish and kōura (freshwater crayfish) were sampled from one control and two treatment reaches of the Utuhina Stream annually. Common bully (Gobiomorphus cotidianus) is the dominant species in the fish community of the Utuhina Stream. Kōura (Paranephrops planifrons) and juvenile trout were always present at all sites but variable in abundance. Differences in species abundance from year to year are most likely due to flood-related disturbances to stream bank morphology and in-stream vegetative cover or physical displacement of fish. No obvious effects of alum dosing on stream fish or macroinvertebrate communities were observed between the upstream control site and sites downstream of the alum discharge. Several other fish species were occasionally captured during sampling and the regular occurrence of juvenile koaro from 2016 to 2019 is possible evidence of this taonga species becoming established in the Utuhina. Analysis of stream macroinvertebrates also showed no consistent differences between the upstream control site and the sites downstream of the alum dosing. Overall, all sites were characterised as fair to good quality for a soft-bottomed stream. Some evidence of aluminium bioaccumulation was seen in some tissues of common bully (gills and liver) in some years, resulting from continuous alum dosing of the Utuhina Stream, but there was no evidence of bioaccumulation of aluminium in the tissues of kōura. Alum exposure in these species does not appear to affect their health or abundance in the stream.   iii Overall, continuous alum discharge does not appear to negatively impact the ecology of the lower Utuhina and improvements in the ecological condition of the Utuhina Stream will be achieved by ongoing riparian restoration and mitigation of the impacts of flood flows.

year: 2021-06