title: Continuous Typist Verification using Machine Learning

authors: Hempstalk, Kathryn

subjects: keystroke verification

abstract: A keyboard is a simple input device.  Its function is to send keystroke information to the computer (or other device) to which it is attached.  Normally this information is employed solely to produce text, but it can also be utilized as part of an authentication system.  Typist verification exploits a typist's patterns to check whether they are who they say they are, even after standard authentication schemes have confirmed their identity.  This thesis investigates whether typists behave in a sufficiently unique yet consistent manner to enable an effective level of verification based on their typing patterns.

Typist verification depends on more than the typist's behaviour.  The quality of the patterns and the algorithms used to compare them also determine how accurately verification is performed.  This thesis sheds light on all technical aspects of the problem, including data collection, feature identification and extraction, and sample classification.  

A dataset has been collected that is comparable in size, timing accuracy and content to others in the field, with one important exception: it is derived from real emails, rather than samples collected in an artificial setting.  This dataset is used to gain insight into what features distinguish typists from one another.  The features and dataset are used to train learning algorithms that make judgements on the origin of previously unseen typing samples.  These algorithms use 'one-class classification'; they make predictions for a particular user having been trained on only that user's patterns.

This thesis examines many one-class classification algorithms, including ones designed specifically for typist verification.  New algorithms and features are proposed to increase speed and accuracy.  The best method proposed performs at the state of the art in terms of classification accuracy, while decreasing the time taken for a prediction from minutes to seconds, and - more importantly - without requiring any negative data from other users.  Also, it is general: it applies not only to typist verification, but to any other one-class classification problem.  

Overall, this thesis concludes that typist verification can be considered a useful biometric technique.

text: Continuous Typist Verification using Machine Learning A keyboard is a simple input device.  Its function is to send keystroke information to the computer (or other device) to which it is attached.  Normally this information is employed solely to produce text, but it can also be utilized as part of an authentication system.  Typist verification exploits a typist's patterns to check whether they are who they say they are, even after standard authentication schemes have confirmed their identity.  This thesis investigates whether typists behave in a sufficiently unique yet consistent manner to enable an effective level of verification based on their typing patterns.

Typist verification depends on more than the typist's behaviour.  The quality of the patterns and the algorithms used to compare them also determine how accurately verification is performed.  This thesis sheds light on all technical aspects of the problem, including data collection, feature identification and extraction, and sample classification.  

A dataset has been collected that is comparable in size, timing accuracy and content to others in the field, with one important exception: it is derived from real emails, rather than samples collected in an artificial setting.  This dataset is used to gain insight into what features distinguish typists from one another.  The features and dataset are used to train learning algorithms that make judgements on the origin of previously unseen typing samples.  These algorithms use 'one-class classification'; they make predictions for a particular user having been trained on only that user's patterns.

This thesis examines many one-class classification algorithms, including ones designed specifically for typist verification.  New algorithms and features are proposed to increase speed and accuracy.  The best method proposed performs at the state of the art in terms of classification accuracy, while decreasing the time taken for a prediction from minutes to seconds, and - more importantly - without requiring any negative data from other users.  Also, it is general: it applies not only to typist verification, but to any other one-class classification problem.  

Overall, this thesis concludes that typist verification can be considered a useful biometric technique.

year: 2009

title: Stratigraphy and Sedimentology of Early to Middle Miocene Strata, Western Taumarunui Region, King Country Basin

authors: Evans, Thomas P. H.

abstract: The study area of this thesis is located in the King Country Basin, North Island, New Zealand. It contains a 400 m thick marine sedimentary succession of Miocene age and Quaternary ignimbrites. The field area comprises 900 km2 of steep to rolling farmland and some large patches of native forest, and includes the towns of Ohura in the west and Taumarunui in the east. There is limited outcrop exposure in the study area, and the sedimentary succession is often weathered. 
The study area is cut by numerous faults that have formed in an extensional regime behind the modem volcanic arc (Taupo Volcanic Zone). The major fault is the Ohura Fault, which has changed its sense of displacement (reverse to normal) in response to changing stress regimes during the Neogene. 
No basement is exposed in the field area, which lies wholly in Early Miocene (Otaian Stage) Mahoenui Group and Mokau Group sediments, and Middle Miocene Mangarara Formation, Otunui Formation, and Mt Messenger Formation sediments. The Mahoenui Group comprises the Taumarunui Formation, characterised by flysch deposits, and the Taumatamaire Formation, a massive mudstone that interfingers with the Taumarunui Formation in the field area. These Early Miocene units represent rapid subsidence and basin formation, with accumulation in outer shelf to slope environments. The Mokau Group comprises the Bexley Sandstone, Maryville Coal Measures, and Tangarakau Formation, which represent an overall marine transgression. The Mangarara Formation is unconformable on the Mahoenui Group, and represents marine transgressive onlap across a land surface cut into the Mahoenui Group during the late-Early Miocene. This unit is overlain by the Otunui Formation, which represents the development of a shelf succession, and which in tum is overlain by the Mt Messenger Formation which represents deposition in slightly deeper waters. Quaternary ignimbrites have a scattered distribution on hill tops in the study area. 
Seven lithofacies have been identifed in the study area, and these have been subdivided into 14 sub-facies. These range from massive mudstone deposited in a bathyal environment, to coal measures deposited in estuarine/swamp/flood plain environments. The facies have been described and interpreted within formations, and the environments for facies associations are inferred. The Mahoenui Group sediments represent deposition in a bathyal setting, and the Mokau Group was deposited in environments ranging from shoreface to inner shelf environments. The Mangarara Formation was deposited in a near shore environment, and the Otunui Formation accumulated in a shelf to uppermost slope setting. The Mount Messenger Formation, which overlies the Otunui Formation mainly south of the field area, occurs at one locality in the study area. 
The King Country Basin developed in response to transpression and crustal shortening related to the inception of the modem plate boundary system through New Zealand during the Early Miocene. The sedimentary succession of the Mahoenui Group, Mokau Group, Mangarara Formation, Otunui Formation and Mt Messenger Formation has developed in response to the coupled effects of tectonism associated with this plate boundary system, and changes in relative sea level.

text: Stratigraphy and Sedimentology of Early to Middle Miocene Strata, Western Taumarunui Region, King Country Basin The study area of this thesis is located in the King Country Basin, North Island, New Zealand. It contains a 400 m thick marine sedimentary succession of Miocene age and Quaternary ignimbrites. The field area comprises 900 km2 of steep to rolling farmland and some large patches of native forest, and includes the towns of Ohura in the west and Taumarunui in the east. There is limited outcrop exposure in the study area, and the sedimentary succession is often weathered. 
The study area is cut by numerous faults that have formed in an extensional regime behind the modem volcanic arc (Taupo Volcanic Zone). The major fault is the Ohura Fault, which has changed its sense of displacement (reverse to normal) in response to changing stress regimes during the Neogene. 
No basement is exposed in the field area, which lies wholly in Early Miocene (Otaian Stage) Mahoenui Group and Mokau Group sediments, and Middle Miocene Mangarara Formation, Otunui Formation, and Mt Messenger Formation sediments. The Mahoenui Group comprises the Taumarunui Formation, characterised by flysch deposits, and the Taumatamaire Formation, a massive mudstone that interfingers with the Taumarunui Formation in the field area. These Early Miocene units represent rapid subsidence and basin formation, with accumulation in outer shelf to slope environments. The Mokau Group comprises the Bexley Sandstone, Maryville Coal Measures, and Tangarakau Formation, which represent an overall marine transgression. The Mangarara Formation is unconformable on the Mahoenui Group, and represents marine transgressive onlap across a land surface cut into the Mahoenui Group during the late-Early Miocene. This unit is overlain by the Otunui Formation, which represents the development of a shelf succession, and which in tum is overlain by the Mt Messenger Formation which represents deposition in slightly deeper waters. Quaternary ignimbrites have a scattered distribution on hill tops in the study area. 
Seven lithofacies have been identifed in the study area, and these have been subdivided into 14 sub-facies. These range from massive mudstone deposited in a bathyal environment, to coal measures deposited in estuarine/swamp/flood plain environments. The facies have been described and interpreted within formations, and the environments for facies associations are inferred. The Mahoenui Group sediments represent deposition in a bathyal setting, and the Mokau Group was deposited in environments ranging from shoreface to inner shelf environments. The Mangarara Formation was deposited in a near shore environment, and the Otunui Formation accumulated in a shelf to uppermost slope setting. The Mount Messenger Formation, which overlies the Otunui Formation mainly south of the field area, occurs at one locality in the study area. 
The King Country Basin developed in response to transpression and crustal shortening related to the inception of the modem plate boundary system through New Zealand during the Early Miocene. The sedimentary succession of the Mahoenui Group, Mokau Group, Mangarara Formation, Otunui Formation and Mt Messenger Formation has developed in response to the coupled effects of tectonism associated with this plate boundary system, and changes in relative sea level.

year: 2003

title: Bilingual Education in Aotearoa/New Zealand

authors: Hill, Richard Kenneth

subjects: Maori medium

abstract: Bilingual education in the context of New Zealand is now over 30 years old. The two largest linguistic minority groups involved in this type of education – the Indigenous Māori and Pasifika peoples of Samoan, Tongan, Cook Islands and Niuean and Tokelauan backgrounds – have made many gains but have struggled in a national context where minority languages have low status. Māori bilingual programs are well established and have made a significant contribution towards reducing Māori language shift that in the 1970s looked to be beyond regeneration. Pasifika bilingual education by contrast is not widely available and not well resourced by the New Zealand government. Both forms continue to need support and a renewed focus at local and national levels.

This chapter provides an overview of past development of Māori and Pasifika bilingual education and present progress. For Māori, the issues relate primarily to how to boost language regeneration, particularly between the generations. Gaining greater support for immersion programs and further strengthening bilingual education pedagogies, particularly relating to achieving biliteracy objectives, are key. In the context of Pasifika, extending government and local support would not only safeguard the languages but has the potential to counteract long-established patterns of low Pasifika student achievement in mainstream/English-medium schooling contexts. Finally, the future of both forms of bilingual education can be safeguarded if they are encompassed within a national languages policy that ensures minority language development in the predominantly English monolingual national context of New Zealand.

text: Bilingual Education in Aotearoa/New Zealand Bilingual education in the context of New Zealand is now over 30 years old. The two largest linguistic minority groups involved in this type of education – the Indigenous Māori and Pasifika peoples of Samoan, Tongan, Cook Islands and Niuean and Tokelauan backgrounds – have made many gains but have struggled in a national context where minority languages have low status. Māori bilingual programs are well established and have made a significant contribution towards reducing Māori language shift that in the 1970s looked to be beyond regeneration. Pasifika bilingual education by contrast is not widely available and not well resourced by the New Zealand government. Both forms continue to need support and a renewed focus at local and national levels.

This chapter provides an overview of past development of Māori and Pasifika bilingual education and present progress. For Māori, the issues relate primarily to how to boost language regeneration, particularly between the generations. Gaining greater support for immersion programs and further strengthening bilingual education pedagogies, particularly relating to achieving biliteracy objectives, are key. In the context of Pasifika, extending government and local support would not only safeguard the languages but has the potential to counteract long-established patterns of low Pasifika student achievement in mainstream/English-medium schooling contexts. Finally, the future of both forms of bilingual education can be safeguarded if they are encompassed within a national languages policy that ensures minority language development in the predominantly English monolingual national context of New Zealand.

year: 2017