title: Maximal Associated Regression: A nonlinear extension to Least Angle Regression

authors: Abeysekera, Sanush K.

abstract: This paper proposes Maximal Associated Regression (MAR), a novel algorithm that performs forward stage-wise regression by applying nonlinear transformations to fit predictor covariates. For each predictor, MAR selects between a linear or additive fit as determined by the dataset. The proposed algorithm is an adaptation of Least Angle Regression (LARS) and retains its efficiency in building sparse models. Constrained penalized splines are used to generate smooth nonlinear transformations for the additive fits. A monotonically constrained extension of MAR (MARm) is also introduced in this paper to fit isotonic regression problems. The proposed algorithms are validated on both synthetic and real datasets. The performances of MAR and MARm are compared against LARS, Generalized Linear Models (GLM), and Generalized Additive Models (GAM) under the Gaussian assumption with a unity link function. Results indicate that MAR-type algorithms achieve a superior subset selection accuracy, generating sparser models that generalize well to new data. MAR is also able to generate models for sample deficient datasets. Thus, MAR is proposed as a valuable tool for subset selection and data exploration, especially when a priori knowledge of the dataset is unavailable.

text: Maximal Associated Regression: A nonlinear extension to Least Angle Regression This paper proposes Maximal Associated Regression (MAR), a novel algorithm that performs forward stage-wise regression by applying nonlinear transformations to fit predictor covariates. For each predictor, MAR selects between a linear or additive fit as determined by the dataset. The proposed algorithm is an adaptation of Least Angle Regression (LARS) and retains its efficiency in building sparse models. Constrained penalized splines are used to generate smooth nonlinear transformations for the additive fits. A monotonically constrained extension of MAR (MARm) is also introduced in this paper to fit isotonic regression problems. The proposed algorithms are validated on both synthetic and real datasets. The performances of MAR and MARm are compared against LARS, Generalized Linear Models (GLM), and Generalized Additive Models (GAM) under the Gaussian assumption with a unity link function. Results indicate that MAR-type algorithms achieve a superior subset selection accuracy, generating sparser models that generalize well to new data. MAR is also able to generate models for sample deficient datasets. Thus, MAR is proposed as a valuable tool for subset selection and data exploration, especially when a priori knowledge of the dataset is unavailable.

year: 2021

title: A review of 3D/4D printing of poly-lactic acid composites with bio-derived reinforcements

authors: Muthe, Lakshmi Priya

abstract: Poly-lactic acid (PLA) has become a commonly used polymer for additive manufacturing because of its bio-derived nature, useful mechanical properties, and excellent processability. Reinforcing PLA with bio-derived materials has been shown to improve the physical, mechanical, and thermal properties of 3D printed composites and, in some cases, to produce active materials for shape-changing hygromorphic structures. PLA also displays shape memory as a response to changes in temperature, making it a popular choice for 4D printing. This review aims to present an overview of the current state of 3D/4D printing PLA composites with bio-derived reinforcements and highlight the recent progress and future opportunities. This comprehensive overview summarises the different forms of bio-derived reinforcements for PLA used in fused deposition modelling (FDM), factors influencing the resulting printed composites’ performance, and research gaps that need addressing. The current methods used before, during, and after printing to enhance the material properties and the impending need for innovative filament production and printing technologies have been brought to attention.

text: A review of 3D/4D printing of poly-lactic acid composites with bio-derived reinforcements Poly-lactic acid (PLA) has become a commonly used polymer for additive manufacturing because of its bio-derived nature, useful mechanical properties, and excellent processability. Reinforcing PLA with bio-derived materials has been shown to improve the physical, mechanical, and thermal properties of 3D printed composites and, in some cases, to produce active materials for shape-changing hygromorphic structures. PLA also displays shape memory as a response to changes in temperature, making it a popular choice for 4D printing. This review aims to present an overview of the current state of 3D/4D printing PLA composites with bio-derived reinforcements and highlight the recent progress and future opportunities. This comprehensive overview summarises the different forms of bio-derived reinforcements for PLA used in fused deposition modelling (FDM), factors influencing the resulting printed composites’ performance, and research gaps that need addressing. The current methods used before, during, and after printing to enhance the material properties and the impending need for innovative filament production and printing technologies have been brought to attention.

year: 2022

title: Rata, the Effect of Māori Land Law on Ahikāroa

authors: Whaanga, Mere Joslyn

subjects: Ahikāroa

abstract: Rata, the effect of Māori land law on ahikāroa is an examination of the special relationship a whānau of Ngāi Tahu (ki Wairoa) has had since 1868 with their ancestral land Tutuotekaha. The effects of Māori land law on traditional concepts of land tenure are analysed from the advent of the Native Land Court in the 1860s through to a modern shareholding in the Anewa Trust. An analysis of Te Ture Whenua Māori Act 1993 looks at the basis for the current legislation and how the principles are applied in the case study central to this thesis, an application to have Rata farm returned to the Whaanga whānau.

The research and writing is multi-disciplinary, combining history, Māori land law (ture) and Māori land lore (tikanga and traditional ecological knowledge). An auto-ethnographic approach is balanced by the commentary and judgements of the Māori Land Court and the Māori Appellate Court which are documented in the final section of the thesis.

This thesis questions the canons of Māori land ownership and management – consolidation, amalgamation and incorporation – and posits whether these forms of land holding have become yet another type of alienation.

The three main areas are
I) Ahikāroa
Chapters 2 and 3 examine traditional Māori land tenure; definitions of mana whenua, the obligations as well as the authority; and traditional ecological knowledge, agriculture and Māori land lore. The latter illustrates ways of knowing the land, how, why and when its resources were used. Members of the community of Iwitea were interviewed to provide accounts of usage of some of the traditional resources known to remain on the Tutuotekaha blocks.

II) From gardeners and gatherers to agricultural shareholders
Chapters 4, 5 and 6 examine the shift from traditional tenure and land usage to large-scale agricultural shareholdings. The changes as land passed through the Native Land Court from 1868 are contextualised within the upheaval and radical reconfiguring of Māori society in the Mahia and Wairoa areas as Pākehā settlement increased, and the region was engulfed by the Hauhau and Te Kooti conflicts. This section contains an overview of Māori land law from 1862 to 1987 and the ideological conflict between the colonisers and the colonised. As well, it looks at the influence of Sir James Carroll and Sir Āpirana Ngata, the reasons that Māori went into large-scale farming and how Ngata’s 1931 policies set the model for the incorporations and trusts that still hold most of the district’s Māori land today.

III) Te Ture Whenua Māori Act 1993, philosophy versus implementation
Chapters 7 through to 11 centre on Te Ture Whenua Māori Act 1993 and the application to the Māori Land Court to partition Rata farm from the Anewa Trust. The philosophy of the Act is examined, aided by Deputy Chief Judge Fox’s commentary. This section documents the processes of filing the application to partition, the discussions and outcomes of a judicial hearing, two Māori Land Court hearings and subsequent appeals to the Māori Appellate Court.

text: Rata, the Effect of Māori Land Law on Ahikāroa Rata, the effect of Māori land law on ahikāroa is an examination of the special relationship a whānau of Ngāi Tahu (ki Wairoa) has had since 1868 with their ancestral land Tutuotekaha. The effects of Māori land law on traditional concepts of land tenure are analysed from the advent of the Native Land Court in the 1860s through to a modern shareholding in the Anewa Trust. An analysis of Te Ture Whenua Māori Act 1993 looks at the basis for the current legislation and how the principles are applied in the case study central to this thesis, an application to have Rata farm returned to the Whaanga whānau.

The research and writing is multi-disciplinary, combining history, Māori land law (ture) and Māori land lore (tikanga and traditional ecological knowledge). An auto-ethnographic approach is balanced by the commentary and judgements of the Māori Land Court and the Māori Appellate Court which are documented in the final section of the thesis.

This thesis questions the canons of Māori land ownership and management – consolidation, amalgamation and incorporation – and posits whether these forms of land holding have become yet another type of alienation.

The three main areas are
I) Ahikāroa
Chapters 2 and 3 examine traditional Māori land tenure; definitions of mana whenua, the obligations as well as the authority; and traditional ecological knowledge, agriculture and Māori land lore. The latter illustrates ways of knowing the land, how, why and when its resources were used. Members of the community of Iwitea were interviewed to provide accounts of usage of some of the traditional resources known to remain on the Tutuotekaha blocks.

II) From gardeners and gatherers to agricultural shareholders
Chapters 4, 5 and 6 examine the shift from traditional tenure and land usage to large-scale agricultural shareholdings. The changes as land passed through the Native Land Court from 1868 are contextualised within the upheaval and radical reconfiguring of Māori society in the Mahia and Wairoa areas as Pākehā settlement increased, and the region was engulfed by the Hauhau and Te Kooti conflicts. This section contains an overview of Māori land law from 1862 to 1987 and the ideological conflict between the colonisers and the colonised. As well, it looks at the influence of Sir James Carroll and Sir Āpirana Ngata, the reasons that Māori went into large-scale farming and how Ngata’s 1931 policies set the model for the incorporations and trusts that still hold most of the district’s Māori land today.

III) Te Ture Whenua Māori Act 1993, philosophy versus implementation
Chapters 7 through to 11 centre on Te Ture Whenua Māori Act 1993 and the application to the Māori Land Court to partition Rata farm from the Anewa Trust. The philosophy of the Act is examined, aided by Deputy Chief Judge Fox’s commentary. This section documents the processes of filing the application to partition, the discussions and outcomes of a judicial hearing, two Māori Land Court hearings and subsequent appeals to the Māori Appellate Court.

year: 2012