title: Using classification to evaluate the output of confidence-based association rule mining

authors: Mutter, Stefan

subjects: computer science

abstract: Association rule mining is a data mining technique that reveals interesting relationships in a database. Existing approaches employ different parameters to search for interesting rules. This fact and the large number of rules make it difficult to compare the output of confidence-based association rule miners. This paper explores the use of classification performance as a metric for evaluating their output. Previous work on forming classifiers from association rules has focussed on accurate classification, whereas we concentrate on using the properties of the resulting classifiers as a basis for comparing confidence-based association rule learners. Therefore, we present experimental results on 12 UCI datasets showing that the quality of small rule sets generated by Apriori can be improved by using the predictive Apriori algorithm. We also show that CBA, the standard method for classification using association rules, is generally inferior to standard rule learners concerning both running time and size of rule sets.

text: Using classification to evaluate the output of confidence-based association rule mining Association rule mining is a data mining technique that reveals interesting relationships in a database. Existing approaches employ different parameters to search for interesting rules. This fact and the large number of rules make it difficult to compare the output of confidence-based association rule miners. This paper explores the use of classification performance as a metric for evaluating their output. Previous work on forming classifiers from association rules has focussed on accurate classification, whereas we concentrate on using the properties of the resulting classifiers as a basis for comparing confidence-based association rule learners. Therefore, we present experimental results on 12 UCI datasets showing that the quality of small rule sets generated by Apriori can be improved by using the predictive Apriori algorithm. We also show that CBA, the standard method for classification using association rules, is generally inferior to standard rule learners concerning both running time and size of rule sets.

year: 2005

title: A continuum model for the dynamics of the phase transition from slow-wave sleep to REM sleep

authors: Sleigh, James W.

subjects: SWS

abstract: Previous studies have shown that activated cortical states (awake and rapid eye-movement (REM) sleep), are associated with increased cholinergic input into the cerebral cortex. However, the mechanisms that underlie the detailed dynamics of the cortical transition from slow-wave to REM sleep have not been quantitatively modeled. How does the sequence of abrupt changes in the cortical dynamics (as detected in the electrocorticogram) result from the more gradual change in subcortical cholinergic input? We compare the output from a continuum model of cortical neuronal dynamics with experimentally-derived rat electrocorticogram data. The output from the computer model was consistent with experimental observations. In slow-wave sleep, 0.5–2-Hz oscillations arise from the cortex jumping between “up” and “down” states on the stationary-state manifold. As cholinergic input increases, the upper state undergoes a bifurcation to an 8-Hz oscillation. The coexistence of both oscillations is similar to that found in the intermediate stage of sleep of the rat. Further cholinergic input moves the trajectory to a point where the lower part of the manifold in not available, and thus the slow oscillation abruptly ceases (REM sleep). The model provides a natural basis to explain neuromodulator-induced changes in cortical activity, and indicates that a cortical phase change, rather than a brainstem “flip-flop”, may describe the transition from slow-wave sleep to REM.

text: A continuum model for the dynamics of the phase transition from slow-wave sleep to REM sleep Previous studies have shown that activated cortical states (awake and rapid eye-movement (REM) sleep), are associated with increased cholinergic input into the cerebral cortex. However, the mechanisms that underlie the detailed dynamics of the cortical transition from slow-wave to REM sleep have not been quantitatively modeled. How does the sequence of abrupt changes in the cortical dynamics (as detected in the electrocorticogram) result from the more gradual change in subcortical cholinergic input? We compare the output from a continuum model of cortical neuronal dynamics with experimentally-derived rat electrocorticogram data. The output from the computer model was consistent with experimental observations. In slow-wave sleep, 0.5–2-Hz oscillations arise from the cortex jumping between “up” and “down” states on the stationary-state manifold. As cholinergic input increases, the upper state undergoes a bifurcation to an 8-Hz oscillation. The coexistence of both oscillations is similar to that found in the intermediate stage of sleep of the rat. Further cholinergic input moves the trajectory to a point where the lower part of the manifold in not available, and thus the slow oscillation abruptly ceases (REM sleep). The model provides a natural basis to explain neuromodulator-induced changes in cortical activity, and indicates that a cortical phase change, rather than a brainstem “flip-flop”, may describe the transition from slow-wave sleep to REM.

year: 2010

title: The contested shift to a bicultural understanding of place heritage in Aotearoa New Zealand

authors: Passey, Emma

abstract: This article explores contemporary threads in the heritage history of Aotearoa New Zealand, as we witness in real-time the emergence of alternative narratives of Indigenous heritage, in contrast to those of Western dominated modernity and colonial hegemony. Moves to actively decolonise heritage studies is creating shifts in the bicultural understanding of culture and heritage to overtly include place heritage. As this new framing emerges, wider acknowledgement of the significance of Māori heritage landscapes is growing. This is explored here in a series of four case-studies. Each account illustrates how Indigenous Māori voices have gained momentum, and reinforces how Aotearoa New Zealand is transitioning to greater bicultural appreciation through inclusion, changes in social and cultural conventions, and new interpretations of dominant narratives using tools like critical heritage studies and existing legal conventions. This evolution of heritage values is not without repeated contestation, however. Positively, increasing numbers of settler-Pākehā (non-Māori) as well as those colonised, no longer believe or accept the histories previously told. Much needed, robust, and sometimes difficult discussions are taking place, enabling New Zealanders to reconsider the significance of what heritage means to all its people.

text: The contested shift to a bicultural understanding of place heritage in Aotearoa New Zealand This article explores contemporary threads in the heritage history of Aotearoa New Zealand, as we witness in real-time the emergence of alternative narratives of Indigenous heritage, in contrast to those of Western dominated modernity and colonial hegemony. Moves to actively decolonise heritage studies is creating shifts in the bicultural understanding of culture and heritage to overtly include place heritage. As this new framing emerges, wider acknowledgement of the significance of Māori heritage landscapes is growing. This is explored here in a series of four case-studies. Each account illustrates how Indigenous Māori voices have gained momentum, and reinforces how Aotearoa New Zealand is transitioning to greater bicultural appreciation through inclusion, changes in social and cultural conventions, and new interpretations of dominant narratives using tools like critical heritage studies and existing legal conventions. This evolution of heritage values is not without repeated contestation, however. Positively, increasing numbers of settler-Pākehā (non-Māori) as well as those colonised, no longer believe or accept the histories previously told. Much needed, robust, and sometimes difficult discussions are taking place, enabling New Zealanders to reconsider the significance of what heritage means to all its people.

year: 2023-01-01