title: Advanced adaptive classifier methods for data streams

authors: Gunasekara, Nuwan Amila

subjects: Stream learning

abstract: The exponential growth of the internet has resulted in an overwhelming influx of big data. However, traditional batch learning models face significant obstacles in effectively learning from these vast and constantly evolving data streams and generating up-to-date outcomes. To overcome these limitations, Stream Learning (SL) has emerged as a promising solution that enables continuous learning from evolving data streams and adapts to changes in input distributions.

This thesis focuses on the classification task of SL, specifically investigating streaming gradient-boosted trees and Neural Network (NN)s. Firstly, we introduce Streaming Gradient Boosted Trees (SGBT), a novel gradient-boosted method designed explicitly for SL classification. Next, we propose Continuously Adaptive Neural Networks for Data Streams (CAND), an architecture-agnostic NN approach for evolving data stream classification. Both SGBT and CAND outperform current state-of-the-art bagging and random forest-based SL methods, demonstrating their superiority in handling evolving data stream classification tasks.

Online Continual Learning (OCL) addresses the issue where NN learning from an evolving data stream forgets its past knowledge when confronted with a distribution shift. Online Domain Incremental Continual Learning (ODICL) is a specific variant of OCL where the input data distribution changes from one task to another. We propose two innovative methods: Online Domain Incremental Pool (ODIP) and Online Domain Incremental Networks (ODIN), for ODICL. The proposed methods leverage existing well-researched SL techniques described in Online Streaming Continual Learning (OSCL). ODIP and ODIN outperform current regularization methods without needing a replay buffer. ODIN achieves competitive results compared to replay-based methods. Both methods are ideal candidates for privacy-concerned ODICL scenarios, offering alternatives to regularization-based approaches.

Overall, this thesis explores advancements in SL classification and ODICL, presenting novel techniques that surpass existing approaches in their respective domains. These contributions have significant implications for addressing the challenges posed by evolving data streams in the era of big data.

text: Advanced adaptive classifier methods for data streams The exponential growth of the internet has resulted in an overwhelming influx of big data. However, traditional batch learning models face significant obstacles in effectively learning from these vast and constantly evolving data streams and generating up-to-date outcomes. To overcome these limitations, Stream Learning (SL) has emerged as a promising solution that enables continuous learning from evolving data streams and adapts to changes in input distributions.

This thesis focuses on the classification task of SL, specifically investigating streaming gradient-boosted trees and Neural Network (NN)s. Firstly, we introduce Streaming Gradient Boosted Trees (SGBT), a novel gradient-boosted method designed explicitly for SL classification. Next, we propose Continuously Adaptive Neural Networks for Data Streams (CAND), an architecture-agnostic NN approach for evolving data stream classification. Both SGBT and CAND outperform current state-of-the-art bagging and random forest-based SL methods, demonstrating their superiority in handling evolving data stream classification tasks.

Online Continual Learning (OCL) addresses the issue where NN learning from an evolving data stream forgets its past knowledge when confronted with a distribution shift. Online Domain Incremental Continual Learning (ODICL) is a specific variant of OCL where the input data distribution changes from one task to another. We propose two innovative methods: Online Domain Incremental Pool (ODIP) and Online Domain Incremental Networks (ODIN), for ODICL. The proposed methods leverage existing well-researched SL techniques described in Online Streaming Continual Learning (OSCL). ODIP and ODIN outperform current regularization methods without needing a replay buffer. ODIN achieves competitive results compared to replay-based methods. Both methods are ideal candidates for privacy-concerned ODICL scenarios, offering alternatives to regularization-based approaches.

Overall, this thesis explores advancements in SL classification and ODICL, presenting novel techniques that surpass existing approaches in their respective domains. These contributions have significant implications for addressing the challenges posed by evolving data streams in the era of big data.

year: 2023

title: Traditional kava use, cognition and driver fitness

authors: Aporosa, S. 'Apo'

abstract: Introduction: Kava (Piper methysticum) is a traditional, culturally significant Pacific Island beverage, which produces soporific relaxant effects similar to Benzodiazepine (Sarris et al, 2012, Journal of Psychopharmacology Clinical and Experimental, 27:262-9). Most research into kava psychopharmacology has utilised kava in extract tablet form (typically 300mg per/day), with the results erroneously overlaid on kava as used in traditional settings. Very little is known about kava’s impacts on cognitive function when consumed traditionally as a drink over many hours, which often amount to more than 15 times the pharmacologically recommended dose. Approximately 70% of kava drinkers drive following use, which has prompted concerns regarding driver impairment. This research builds on two earlier studies (Aporosa et al, 2020, Journal of Human Psychopharmacology, 35[2]:e2725) to investigate the effects of kava on six cognition-related functions associated with driving.  
Methods:  The study was guided by the Pacific Post-development Methodological Framework to ensure the ethical and equitable use of Western standardised psychometrics among Pacific peoples (Aporosa et al., Pacific Dynamics, 5[1]:74-92). Experienced male kava users (n=20, mean age = 34.75) attended a six hour traditionally influenced kava session. Each participant consumed 3.6 litres (6.33 pints) of kava, equating to 3,680mg of kavalactones.  Also present were a control group of non-kava consuming males (n=19, mean age = 35.57). At baseline, the participants completed computerised somato-sensory psychometric tests (using the Brain Gauge [www.corticalmetrics.com]) to measure six strategic, tactical and operational functions, including fine-motor-skills and fatigue.  Re-testing was conducted three and six hours after kava consumption.  Pre/post analysis compared within person and between group differences.  Statistical modelling was based on t-tests and Bayesian analysis.  
Results: Test data revealed significant impairment (p<0.05) to only one of the six functions assessed by the Brain Gauge  ̶  Temporal Order Judgement (TOJ) [t=0.007; B=6.193].
Conclusion: When ingested in traditional use volumes, kava did not impact participants’ Focus, Accuracy, Timing Perception, Plasticity or Fatigue, but there was a significant negative impact on TOJ. TOJ (as measured by the Brain Gauge) is chiefly associated with sequencing linked to executive functions allied with decision making, behavioural control, and information processing (Aporosa et al., 2022, Journal of Ethnopharmacology, 291[115080]:1-15). These new findings suggest that traditional kava use effects are unique and subtle, and manifest very differently to alcohol, cannabis and hallucinogens. Nevertheless, kava effects may compromise driver safety. The study was followed up with a culture-friendly kava drink-driving awareness campaign.

text: Traditional kava use, cognition and driver fitness Introduction: Kava (Piper methysticum) is a traditional, culturally significant Pacific Island beverage, which produces soporific relaxant effects similar to Benzodiazepine (Sarris et al, 2012, Journal of Psychopharmacology Clinical and Experimental, 27:262-9). Most research into kava psychopharmacology has utilised kava in extract tablet form (typically 300mg per/day), with the results erroneously overlaid on kava as used in traditional settings. Very little is known about kava’s impacts on cognitive function when consumed traditionally as a drink over many hours, which often amount to more than 15 times the pharmacologically recommended dose. Approximately 70% of kava drinkers drive following use, which has prompted concerns regarding driver impairment. This research builds on two earlier studies (Aporosa et al, 2020, Journal of Human Psychopharmacology, 35[2]:e2725) to investigate the effects of kava on six cognition-related functions associated with driving.  
Methods:  The study was guided by the Pacific Post-development Methodological Framework to ensure the ethical and equitable use of Western standardised psychometrics among Pacific peoples (Aporosa et al., Pacific Dynamics, 5[1]:74-92). Experienced male kava users (n=20, mean age = 34.75) attended a six hour traditionally influenced kava session. Each participant consumed 3.6 litres (6.33 pints) of kava, equating to 3,680mg of kavalactones.  Also present were a control group of non-kava consuming males (n=19, mean age = 35.57). At baseline, the participants completed computerised somato-sensory psychometric tests (using the Brain Gauge [www.corticalmetrics.com]) to measure six strategic, tactical and operational functions, including fine-motor-skills and fatigue.  Re-testing was conducted three and six hours after kava consumption.  Pre/post analysis compared within person and between group differences.  Statistical modelling was based on t-tests and Bayesian analysis.  
Results: Test data revealed significant impairment (p<0.05) to only one of the six functions assessed by the Brain Gauge  ̶  Temporal Order Judgement (TOJ) [t=0.007; B=6.193].
Conclusion: When ingested in traditional use volumes, kava did not impact participants’ Focus, Accuracy, Timing Perception, Plasticity or Fatigue, but there was a significant negative impact on TOJ. TOJ (as measured by the Brain Gauge) is chiefly associated with sequencing linked to executive functions allied with decision making, behavioural control, and information processing (Aporosa et al., 2022, Journal of Ethnopharmacology, 291[115080]:1-15). These new findings suggest that traditional kava use effects are unique and subtle, and manifest very differently to alcohol, cannabis and hallucinogens. Nevertheless, kava effects may compromise driver safety. The study was followed up with a culture-friendly kava drink-driving awareness campaign.

year: 2022

title: A Case for an Indigenous Court - a realisation of self-determination?

authors: Toki, Valmaine

subjects: Indigenous

abstract: This thesis searches for appropriate ways to alter entrenched patterns of highly negative outcomes for Māori in the criminal justice system. The statistics demonstrate that proportionately, Māori are much more likely to be apprehended, arrested, prosecuted, convicted and incarcerated than other New Zealanders and ethnic groups, and much less likely to be granted parole. 

An overview of the current relationship between Māori and the criminal justice system provides a background to begin understanding these long-standing patterns. An examination of the ancestral conceptions of tikanga Māori, including issues of proper conduct, punishment, behaviour and attaining balance, provides a persuasive framework to positively transform the criminal justice system. In order to understand why tikanga Māori is not meaningfully realised today, an historical review of the introduction of English law and legal systems clarifies the negative and almost fatal impact English law had on tikanga Māori. 

An evaluation of two instruments — Treaty of Waitangi and the United Nations Declaration on the Rights of Indigenous Peoples — provides further context for this dialogue. A specific focus on the right to culture and the right of self-determination, within these two documents, highlights the need to meaningfully revisit and/or realise these rights as a pathway to recognise the concepts of tikanga Māori. A review of comparative jurisdictions indicates existing support for the right to culture and the right of self-determination within respective legal systems and constitutions. 

An examination of the current criminal justice initiatives and policies in New Zealand highlights the status quo. This current status quo is set against initiatives in comparative jurisdictions. Following a domestic and international analysis, models underpinned by therapeutic jurisprudence and tikanga Māori, are suggested as a potential way forward for Māori to realise a form of self-determination.


In conclusion, new frameworks are proposed. These may provide an opportunity to apply the philosophy of Te Ao Māori, realised by an indigenous legal system, manifested by an indigenous court premised on fundamental Māori concepts and doctrine as the most promising way forward for Māori to ameliorate the disproportionate offending rates. A suggested extension to the Māori Land Court to include a criminal jurisdiction or, alternatively, a Tikanga Court is proposed.

text: A Case for an Indigenous Court - a realisation of self-determination? This thesis searches for appropriate ways to alter entrenched patterns of highly negative outcomes for Māori in the criminal justice system. The statistics demonstrate that proportionately, Māori are much more likely to be apprehended, arrested, prosecuted, convicted and incarcerated than other New Zealanders and ethnic groups, and much less likely to be granted parole. 

An overview of the current relationship between Māori and the criminal justice system provides a background to begin understanding these long-standing patterns. An examination of the ancestral conceptions of tikanga Māori, including issues of proper conduct, punishment, behaviour and attaining balance, provides a persuasive framework to positively transform the criminal justice system. In order to understand why tikanga Māori is not meaningfully realised today, an historical review of the introduction of English law and legal systems clarifies the negative and almost fatal impact English law had on tikanga Māori. 

An evaluation of two instruments — Treaty of Waitangi and the United Nations Declaration on the Rights of Indigenous Peoples — provides further context for this dialogue. A specific focus on the right to culture and the right of self-determination, within these two documents, highlights the need to meaningfully revisit and/or realise these rights as a pathway to recognise the concepts of tikanga Māori. A review of comparative jurisdictions indicates existing support for the right to culture and the right of self-determination within respective legal systems and constitutions. 

An examination of the current criminal justice initiatives and policies in New Zealand highlights the status quo. This current status quo is set against initiatives in comparative jurisdictions. Following a domestic and international analysis, models underpinned by therapeutic jurisprudence and tikanga Māori, are suggested as a potential way forward for Māori to realise a form of self-determination.


In conclusion, new frameworks are proposed. These may provide an opportunity to apply the philosophy of Te Ao Māori, realised by an indigenous legal system, manifested by an indigenous court premised on fundamental Māori concepts and doctrine as the most promising way forward for Māori to ameliorate the disproportionate offending rates. A suggested extension to the Māori Land Court to include a criminal jurisdiction or, alternatively, a Tikanga Court is proposed.

year: 2016