title: New Options for Hoeffding Trees

authors: Pfahringer, Bernhard

subjects: computer science

abstract: Hoeffding trees are state-of-the-art for processing high-speed data streams. Their ingenuity stems from updating sufficient statistics, only addressing growth when decisions can be made that are guaranteed to be almost identical to those that would be made by conventional batch learning methods. Despite this guarantee, decisions are still subject to limited lookahead and stability issues. In this paper we explore Hoeffding Option Trees, a regular Hoeffding tree containing additional option nodes that allow several tests to be applied, leading to multiple Hoeffding trees as separate paths. We show how to control tree growth in order to generate a mixture of paths, and empirically determine a reasonable number of paths. We then empirically evaluate a spectrum of Hoeffding tree variations: single trees, option trees and bagged trees. Finally, we investigate pruning. We show that on some datasets a pruned option tree can be smaller and more accurate than a single tree.

text: New Options for Hoeffding Trees Hoeffding trees are state-of-the-art for processing high-speed data streams. Their ingenuity stems from updating sufficient statistics, only addressing growth when decisions can be made that are guaranteed to be almost identical to those that would be made by conventional batch learning methods. Despite this guarantee, decisions are still subject to limited lookahead and stability issues. In this paper we explore Hoeffding Option Trees, a regular Hoeffding tree containing additional option nodes that allow several tests to be applied, leading to multiple Hoeffding trees as separate paths. We show how to control tree growth in order to generate a mixture of paths, and empirically determine a reasonable number of paths. We then empirically evaluate a spectrum of Hoeffding tree variations: single trees, option trees and bagged trees. Finally, we investigate pruning. We show that on some datasets a pruned option tree can be smaller and more accurate than a single tree.

year: 2007

title: Na gunu yaqona ena kena ivalavala vei keda na itaukei, na vakasama vata kei na vakatulewa e sala muria mai; vata kei na ituvaki vinaka ni vakasama nei koya na dau ni vakau motoka. Traditional kava-drinking, cognition and driver fitness [Fijian]

authors: Aporosa, S. 'Apo'

abstract: E robota vakarabailevu na Pasivika na tubu ni itei ni yaqona, se ‘na nodra itei na Kalou Vu’. E vakayagataki me wainimate vakaViti, e tuki tale ga na wakana ka lose ena waidroka ka tauvuloni me gunuvi ka igunugunu veivakacegui. E tiko na ikilai vakavanua ni yaqona, ia baleta ni sa gunuvi vakasivia ena loma ni vica na auwa, sa vure cake mai na kauwai ena vuku ni kena revurevu ki na nodra tataqomaki na draiva. A sa vulica o Dr ‘Apo’ Aporosa, e dua na Research Fellow ena univesiti ni Waikato e Niusiladi na revurevu ni kena vakayagataki vakavanua na yaqona ki na ituvaki vinaka ni vakasama kei na veika e vakavurea ena ituvaki vinaka ni draiva. E vulica o Dr ‘Apo’ Aporosa na revurevu ni vakayagataki vakavanua ni yaqona ki na ituvaki vinaka ni vakasama kei na veika e vakavurea ena ituvaki vinaka ni draiva. 

(Kava, or ‘the plant of the gods’, grows widely across tropical Moananuiākea (the Pacific). Used in traditional medicine, its roots are also pounded and strained through water to make a drink with relaxant effects. Kava has deep cultural significance, but because it is drunk in large quantities over several hours, concerns have been raised about its effects on driver safety. Dr ‘Apo’ Aporosa, a Research Fellow at the University of Waikato in New Zealand, has studied the impact of traditional kava use on cognition and its implications for driver fitness. The findings of that research are presented here in the Fijian language.)

text: Na gunu yaqona ena kena ivalavala vei keda na itaukei, na vakasama vata kei na vakatulewa e sala muria mai; vata kei na ituvaki vinaka ni vakasama nei koya na dau ni vakau motoka. Traditional kava-drinking, cognition and driver fitness [Fijian] E robota vakarabailevu na Pasivika na tubu ni itei ni yaqona, se ‘na nodra itei na Kalou Vu’. E vakayagataki me wainimate vakaViti, e tuki tale ga na wakana ka lose ena waidroka ka tauvuloni me gunuvi ka igunugunu veivakacegui. E tiko na ikilai vakavanua ni yaqona, ia baleta ni sa gunuvi vakasivia ena loma ni vica na auwa, sa vure cake mai na kauwai ena vuku ni kena revurevu ki na nodra tataqomaki na draiva. A sa vulica o Dr ‘Apo’ Aporosa, e dua na Research Fellow ena univesiti ni Waikato e Niusiladi na revurevu ni kena vakayagataki vakavanua na yaqona ki na ituvaki vinaka ni vakasama kei na veika e vakavurea ena ituvaki vinaka ni draiva. E vulica o Dr ‘Apo’ Aporosa na revurevu ni vakayagataki vakavanua ni yaqona ki na ituvaki vinaka ni vakasama kei na veika e vakavurea ena ituvaki vinaka ni draiva. 

(Kava, or ‘the plant of the gods’, grows widely across tropical Moananuiākea (the Pacific). Used in traditional medicine, its roots are also pounded and strained through water to make a drink with relaxant effects. Kava has deep cultural significance, but because it is drunk in large quantities over several hours, concerns have been raised about its effects on driver safety. Dr ‘Apo’ Aporosa, a Research Fellow at the University of Waikato in New Zealand, has studied the impact of traditional kava use on cognition and its implications for driver fitness. The findings of that research are presented here in the Fijian language.)

year: 2023

title: Connections, working collaboratively and health workforce development

authors: Masters-Awatere, Bridgette

subjects: Rangahau Māori

abstract: I was invited to deliver a presentation as part of the Inaugral series of research symposia hosted by the national Maori health authority - Te Aka Whaiora

text: Connections, working collaboratively and health workforce development I was invited to deliver a presentation as part of the Inaugral series of research symposia hosted by the national Maori health authority - Te Aka Whaiora

year: 2023-08-30