title: Fast perceptron decision tree learning from evolving data streams

authors: Bifet, Albert

subjects: computer science

abstract: Mining of data streams must balance three evaluation dimensions: accuracy, time and memory. Excellent accuracy on data streams has been obtained with Naive Bayes Hoeffding Trees—Hoeffding Trees with naive Bayes models at the leaf nodes—albeit with increased runtime compared to standard Hoeffding Trees. In this paper, we show that runtime can be reduced by replacing naive Bayes with perceptron classifiers, while maintaining highly competitive accuracy. We also show that accuracy can be increased even further by combining majority vote, naive Bayes, and perceptrons. We evaluate four perceptron-based learning strategies and compare them against appropriate baselines: simple perceptrons, Perceptron Hoeffding Trees, hybrid Naive Bayes Perceptron Trees, and bagged versions thereof. We implement a perceptron that uses the sigmoid activation function instead of the threshold activation function and optimizes the squared error, with one perceptron per class value. We test our methods by performing an evaluation study on synthetic and real-world datasets comprising up to ten million examples.

text: Fast perceptron decision tree learning from evolving data streams Mining of data streams must balance three evaluation dimensions: accuracy, time and memory. Excellent accuracy on data streams has been obtained with Naive Bayes Hoeffding Trees—Hoeffding Trees with naive Bayes models at the leaf nodes—albeit with increased runtime compared to standard Hoeffding Trees. In this paper, we show that runtime can be reduced by replacing naive Bayes with perceptron classifiers, while maintaining highly competitive accuracy. We also show that accuracy can be increased even further by combining majority vote, naive Bayes, and perceptrons. We evaluate four perceptron-based learning strategies and compare them against appropriate baselines: simple perceptrons, Perceptron Hoeffding Trees, hybrid Naive Bayes Perceptron Trees, and bagged versions thereof. We implement a perceptron that uses the sigmoid activation function instead of the threshold activation function and optimizes the squared error, with one perceptron per class value. We test our methods by performing an evaluation study on synthetic and real-world datasets comprising up to ten million examples.

year: 2010

title: Contracting out local government services: A comparative study of two New Zealand regional councils

authors: McLeod, Anne

subjects: New Zealand

abstract: Studies of New Zealand public sector reforms since the mid-1980s have tended to focus on the application of New Public Management principles to the central government. Yet local government in New Zealand too has experienced drastic restructuring with a view to ensuring greater rationalisation, efficiency and effectiveness. This article examines contracting out in New Zealand local government, focusing on the delivery of plant pest management by Environment Waikato(the Waikato Regional Council) and the Wellington Regional Council. The study reveals distinct differences in approach by the two councils, determined in each case by pragmatic responses to situational context rather than mere adherence to NPM principles.

text: Contracting out local government services: A comparative study of two New Zealand regional councils Studies of New Zealand public sector reforms since the mid-1980s have tended to focus on the application of New Public Management principles to the central government. Yet local government in New Zealand too has experienced drastic restructuring with a view to ensuring greater rationalisation, efficiency and effectiveness. This article examines contracting out in New Zealand local government, focusing on the delivery of plant pest management by Environment Waikato(the Waikato Regional Council) and the Wellington Regional Council. The study reveals distinct differences in approach by the two councils, determined in each case by pragmatic responses to situational context rather than mere adherence to NPM principles.

year: 2004

title: Barry Barclay: the Reflection of Maori and Pakeha Identities

authors: Hilal, Emad Jabbar

subjects: emad

abstract: This Media and Screen Studies thesis tries to investigate the identifications of Barry Barclay (1944-2008) - a New Zealand filmmaker, thinker and poet, of Māori and Pākeha ethnic background - who identified as Māori in the second part of his career, in the mid 1970s. The thesis relies on Barclay's writing and other historical and theoretical material in the reading of his own films. The thesis arrives at an argument that even when Barclay chose to identify more with the Māori side of his identity, the Pākeha side took part also in the shaping of his film practices. Studying Barry Barclay along this line of argument has several benefits for Screen Studies. It, on the one hand, covers what is left unstudied by the scholarship concerning his representation of the Māori world such as the way he commented on Māori cultural and social concerns and acheivements in his films. The thesis studies Barclay's films from the time he started his identification with his Māori  side in Tangaata Whenua (1974), Te Urewera (1987), Ngati (1987),Te Rua (1991) and takes The Kaipara Affair (2005) as a case study and a carrier of change in film practices and development in outlook.The other important contribution is the way he represented Pākeha, and how he developed his representation of them in time. This representation which is unstudied at all, is important to Screen Studies becuase it contributes to Barclay's theory of Fourth Cinema. This thesis shows how representing Pakeha, especially in Barclay's last film problemematizes his theory of Fourth Cinema, but ultimately, deals with applies it creatively. The representation of Pākeha gives insight into Barclay's interest in the Māori world, which is not a dogma or a merely ethnic affiliation as much as an attraction to a world-view that can solve major universal issues such as environmental problems. Above all, the way how Barclay worked out this representation in his films sheds light on one of the important examples of how film can take part in healing social damages such as the history of colonizing and marginalization of Māori people.

text: Barry Barclay: the Reflection of Maori and Pakeha Identities This Media and Screen Studies thesis tries to investigate the identifications of Barry Barclay (1944-2008) - a New Zealand filmmaker, thinker and poet, of Māori and Pākeha ethnic background - who identified as Māori in the second part of his career, in the mid 1970s. The thesis relies on Barclay's writing and other historical and theoretical material in the reading of his own films. The thesis arrives at an argument that even when Barclay chose to identify more with the Māori side of his identity, the Pākeha side took part also in the shaping of his film practices. Studying Barry Barclay along this line of argument has several benefits for Screen Studies. It, on the one hand, covers what is left unstudied by the scholarship concerning his representation of the Māori world such as the way he commented on Māori cultural and social concerns and acheivements in his films. The thesis studies Barclay's films from the time he started his identification with his Māori  side in Tangaata Whenua (1974), Te Urewera (1987), Ngati (1987),Te Rua (1991) and takes The Kaipara Affair (2005) as a case study and a carrier of change in film practices and development in outlook.The other important contribution is the way he represented Pākeha, and how he developed his representation of them in time. This representation which is unstudied at all, is important to Screen Studies becuase it contributes to Barclay's theory of Fourth Cinema. This thesis shows how representing Pakeha, especially in Barclay's last film problemematizes his theory of Fourth Cinema, but ultimately, deals with applies it creatively. The representation of Pākeha gives insight into Barclay's interest in the Māori world, which is not a dogma or a merely ethnic affiliation as much as an attraction to a world-view that can solve major universal issues such as environmental problems. Above all, the way how Barclay worked out this representation in his films sheds light on one of the important examples of how film can take part in healing social damages such as the history of colonizing and marginalization of Māori people.

year: 2017