title: Hidden features: Experiments with feature transfer for fine-grained multi-class and one-class image categorization

authors: Vetrova, Varvara

subjects: Science & Technology

abstract: Can we apply out-of-the box feature transfer using pre-trained convolutional neural networks in fine-grained multiclass image categorization tasks? What is the effect of (a) domainspecific fine-tuning and (b) a special-purpose network architecture designed and trained specifically for the target domain? How do these approaches perform in one-class classification? We investigate these questions by tackling two biological object recognition tasks: classification of “cryptic” plants of genus Coprosma and identification of New Zealand moth species. We compare results based on out-of-the-box features extracted using a pre-trained state-of-the-art network to those obtained by finetuning to the target domain, and also evaluate features learned using a simple Siamese network trained only on data from the target domain. For each extracted feature set, we test a number of classifiers, e.g., support vector machines. In addition to multiclass classification, we also consider one-class classification, a scenario that is particularly relevant to biosecurity applications.
In the multi-class setting, we find that out-of-the-box lowlevel features extracted from the generic pre-trained network yield high accuracy (90.76%) when coupled with a simple LDA classifier. Fine-tuning improves accuracy only slightly (to 91.6%). Interestingly, features extracted from the much simpler Siamese network trained on data from the target domain lead to comparable results (90.8%). In the one-class classification setting, we note high variability in the area under the ROC curve across feature sets, opening up the possibility of considering an ensemble approach.

text: Hidden features: Experiments with feature transfer for fine-grained multi-class and one-class image categorization Can we apply out-of-the box feature transfer using pre-trained convolutional neural networks in fine-grained multiclass image categorization tasks? What is the effect of (a) domainspecific fine-tuning and (b) a special-purpose network architecture designed and trained specifically for the target domain? How do these approaches perform in one-class classification? We investigate these questions by tackling two biological object recognition tasks: classification of “cryptic” plants of genus Coprosma and identification of New Zealand moth species. We compare results based on out-of-the-box features extracted using a pre-trained state-of-the-art network to those obtained by finetuning to the target domain, and also evaluate features learned using a simple Siamese network trained only on data from the target domain. For each extracted feature set, we test a number of classifiers, e.g., support vector machines. In addition to multiclass classification, we also consider one-class classification, a scenario that is particularly relevant to biosecurity applications.
In the multi-class setting, we find that out-of-the-box lowlevel features extracted from the generic pre-trained network yield high accuracy (90.76%) when coupled with a simple LDA classifier. Fine-tuning improves accuracy only slightly (to 91.6%). Interestingly, features extracted from the much simpler Siamese network trained on data from the target domain lead to comparable results (90.8%). In the one-class classification setting, we note high variability in the area under the ROC curve across feature sets, opening up the possibility of considering an ensemble approach.

year: 2018

title: Children’s views of their teacher’s role in helping them learn mathematics

authors: Taylor, Merilyn

subjects: education

abstract: This paper reports on data from 183 nine-to eleven-year old children attending six Waikato schools. An analysis is provided of children’s responses to a question about their teacher’s role in helping them learn mathematics. Four major roles were identified, including mentor, classroom manager, transmitter of information, and arbiter of decisions. The implications for students’ mathematics learning of viewing their teacher in each of these roles are then discussed. The importance for teachers of recognising the ways they are perceived by their students is also considered.

text: Children’s views of their teacher’s role in helping them learn mathematics This paper reports on data from 183 nine-to eleven-year old children attending six Waikato schools. An analysis is provided of children’s responses to a question about their teacher’s role in helping them learn mathematics. Four major roles were identified, including mentor, classroom manager, transmitter of information, and arbiter of decisions. The implications for students’ mathematics learning of viewing their teacher in each of these roles are then discussed. The importance for teachers of recognising the ways they are perceived by their students is also considered.

year: 2005

title: Tino rangatiratanga in health policies and practises

authors: Wihongi, Helen Annette

subjects: tino rangatiratanga

abstract: The purpose of my doctoral research was to investigate tino rangatiratanga in health policies and practises in Aotearoa. My research involved defining tino rangatiratanga and exploring the expression of tino rangatiratanga in health policy and practises. A kaupapa Māori analysis of the 1996 National Cervical Screening Programme’s Policy document was at the core of the policy investigation. The analysis involved developing a kaupapa Māori analysing framework and then analysing the 1996 National Cervical Screening Policy document for empirical and normative judgements at four discursive levels, health gains, health objectives, health goals and fundamental underlying values. A Kaupapa Māori research design drew on interdisciplinary scholarship on colonisation, Te Tiriti o Waitangi, community psychology, public policy, disability theory, feminist theory and discourse theory.

I argue that the dominance of Western cultural norms and state-directed policies were made possible by the signing of Te Tiriti o Waitangi. The signing of Te Tiriti saw Crown sovereignty being implemented and tino rangatiratanga ignored. The consequences for Māori have been disastrous with loss of land and economic base which has resulted in poor health status. I also argue that tino rangatiratanga has the potential to transform the social and political context that frame Aotearoa society. Such an approach raises a critical dilemma for the state as meaningful recognition of tino rangatiratanga requires waiving full and absolute sovereignty which currently resides in the state. Hence some scholars argue that tino rangatiratanga is a site for constructive engagement where state and Māori relationships can be renegotiated. The extent to which this potential for constructive engagement is being realised in however is inadequately explored in the scholarly literature. Exploring the relationships between tino rangatiratanga and health policies and practises as undertaken in my thesis will therefore contribute to scholarly knowledge on the subject.

The findings from the research show that tino rangatiratanga is indeed a complex, fluid, multi-faceted and context related concept. Within the context of my research, tino rangatiratanga is defined as Māori sovereignty, self determination, and positive Māori development. As a Māori value it is about mana and tapu of rangatira or leadership personified. Within policies, tino rangatiratanga has emerged through resistance and demonstration and is actualised through Tiriti legislation and policies.

The legitimation of tino rangatiratanga in cervical screening services sees Māori leadership at national, regional and local levels and Māori involvement through wide ranging consultation but the Crown still controls the policy process and therefore the outcomes. Most cervical screening services are still owned and operated by the Crown or Crown agencies.

One of the consequences of Crown control is that Māori women are still twice as likely to get cervical cancer and four times more likely to die from it. To some degree this may be the result of resource allocation and the result of discriminatory service practices but also the result of resistance to the procedure itself.

Tino rangatiratanga within cervical screening services could be strengthened through iwi ownership of some cervical screening register sites. At the time of my field work (2000) there were 14 sites, all owned and operated by Crown agents. Tino rangatiratanga could also be strengthened through funding criteria that ensure practitioners are safe to practise, through the adoption of less invasive procedures and through the legitimation of Māori healing practises such as rongoā and karakia.

Overall if tino rangatiratanga is to be given full effect within the policy domain Māori must have a well established asset base, they must be in control of the decision making making process including resource allocation, service delivery must address the diversities of Māori realities and Māori must be the recipients of policy decisions made.

text: Tino rangatiratanga in health policies and practises The purpose of my doctoral research was to investigate tino rangatiratanga in health policies and practises in Aotearoa. My research involved defining tino rangatiratanga and exploring the expression of tino rangatiratanga in health policy and practises. A kaupapa Māori analysis of the 1996 National Cervical Screening Programme’s Policy document was at the core of the policy investigation. The analysis involved developing a kaupapa Māori analysing framework and then analysing the 1996 National Cervical Screening Policy document for empirical and normative judgements at four discursive levels, health gains, health objectives, health goals and fundamental underlying values. A Kaupapa Māori research design drew on interdisciplinary scholarship on colonisation, Te Tiriti o Waitangi, community psychology, public policy, disability theory, feminist theory and discourse theory.

I argue that the dominance of Western cultural norms and state-directed policies were made possible by the signing of Te Tiriti o Waitangi. The signing of Te Tiriti saw Crown sovereignty being implemented and tino rangatiratanga ignored. The consequences for Māori have been disastrous with loss of land and economic base which has resulted in poor health status. I also argue that tino rangatiratanga has the potential to transform the social and political context that frame Aotearoa society. Such an approach raises a critical dilemma for the state as meaningful recognition of tino rangatiratanga requires waiving full and absolute sovereignty which currently resides in the state. Hence some scholars argue that tino rangatiratanga is a site for constructive engagement where state and Māori relationships can be renegotiated. The extent to which this potential for constructive engagement is being realised in however is inadequately explored in the scholarly literature. Exploring the relationships between tino rangatiratanga and health policies and practises as undertaken in my thesis will therefore contribute to scholarly knowledge on the subject.

The findings from the research show that tino rangatiratanga is indeed a complex, fluid, multi-faceted and context related concept. Within the context of my research, tino rangatiratanga is defined as Māori sovereignty, self determination, and positive Māori development. As a Māori value it is about mana and tapu of rangatira or leadership personified. Within policies, tino rangatiratanga has emerged through resistance and demonstration and is actualised through Tiriti legislation and policies.

The legitimation of tino rangatiratanga in cervical screening services sees Māori leadership at national, regional and local levels and Māori involvement through wide ranging consultation but the Crown still controls the policy process and therefore the outcomes. Most cervical screening services are still owned and operated by the Crown or Crown agencies.

One of the consequences of Crown control is that Māori women are still twice as likely to get cervical cancer and four times more likely to die from it. To some degree this may be the result of resource allocation and the result of discriminatory service practices but also the result of resistance to the procedure itself.

Tino rangatiratanga within cervical screening services could be strengthened through iwi ownership of some cervical screening register sites. At the time of my field work (2000) there were 14 sites, all owned and operated by Crown agents. Tino rangatiratanga could also be strengthened through funding criteria that ensure practitioners are safe to practise, through the adoption of less invasive procedures and through the legitimation of Māori healing practises such as rongoā and karakia.

Overall if tino rangatiratanga is to be given full effect within the policy domain Māori must have a well established asset base, they must be in control of the decision making making process including resource allocation, service delivery must address the diversities of Māori realities and Māori must be the recipients of policy decisions made.

year: 2010