title: A novel ‘FlocDrifter’ platform for observing flocculation and turbulence processes in a Lagrangian frame of reference

authors: MacDonald, Iain T.

abstract: A novel drifter platform was used to measure the properties of aggregated particles called flocs—a key component of sediment transport in muddy environments. Also concurrently measured were turbulence, suspended sediment concentration (SSC), velocity, and salinity in both Lagrangian and Eulerian frames of reference. In Lagrangian mode the system performed well in a heavily sediment-laden river, providing measurements over a large spatial scale. The platform navigated itself through a complex geometry encompassing many bends and significant depth changes. Observed velocities relative to the drifter and salinities indicated that the drifter motion was almost Lagrangian with minimal slippage between the drifter and the water motion. The small amount of slippage that did occur was sufficient to ensure that the drifter oriented itself into the oncoming flow. 
High-quality in situ images of flocs were collected using a high-magnification floc camera (FlocCam). An automatic image analysis routine was developed to identify and characterize flocs within each FlocCam image, employing an artificial neural network (ANN) to ensure that only in-focus particles were included in the analyses. The results indicated that the FlocCam system had an upper working SSC limit of around 350–400 mg L⁻¹. 
The SSC estimates show that the drifters encountered considerable variability as they were advected downstream; however, concentrations predominantly remained under the image processing threshold of 350–400 mg L⁻¹. The system captured the evolution of floc characteristics over short spatial scales (hundreds of meters). The median floc size (d₅₀) was found to be positively correlated with SSC (r² = 0.5). A comparison between Eulerian and Lagrangian floc histories can then be used to evaluate the role of antecedent conditions within the flocculation process.

text: A novel ‘FlocDrifter’ platform for observing flocculation and turbulence processes in a Lagrangian frame of reference A novel drifter platform was used to measure the properties of aggregated particles called flocs—a key component of sediment transport in muddy environments. Also concurrently measured were turbulence, suspended sediment concentration (SSC), velocity, and salinity in both Lagrangian and Eulerian frames of reference. In Lagrangian mode the system performed well in a heavily sediment-laden river, providing measurements over a large spatial scale. The platform navigated itself through a complex geometry encompassing many bends and significant depth changes. Observed velocities relative to the drifter and salinities indicated that the drifter motion was almost Lagrangian with minimal slippage between the drifter and the water motion. The small amount of slippage that did occur was sufficient to ensure that the drifter oriented itself into the oncoming flow. 
High-quality in situ images of flocs were collected using a high-magnification floc camera (FlocCam). An automatic image analysis routine was developed to identify and characterize flocs within each FlocCam image, employing an artificial neural network (ANN) to ensure that only in-focus particles were included in the analyses. The results indicated that the FlocCam system had an upper working SSC limit of around 350–400 mg L⁻¹. 
The SSC estimates show that the drifters encountered considerable variability as they were advected downstream; however, concentrations predominantly remained under the image processing threshold of 350–400 mg L⁻¹. The system captured the evolution of floc characteristics over short spatial scales (hundreds of meters). The median floc size (d₅₀) was found to be positively correlated with SSC (r² = 0.5). A comparison between Eulerian and Lagrangian floc histories can then be used to evaluate the role of antecedent conditions within the flocculation process.

year: 2015

title: Toward multi-objective optimisation for Lake Taupo water level managment

authors: Bardsley, W. Earl

subjects: Lake Taupo

abstract: A multi-goal optimisation strategy may provide a basis for Lake Taupō water management. This involves defining an agreed ‘optimal zone’ of lake levels which are away from both high and low levels. The aim of water releases to the Waikato River would be to maximise the duration that lake levels are within the optimal zone, while also seeking to meet other, possibly conflicting, goals such as optimal hydro power operation.
A sense of how a multi-goal model could operate is given, by considering a simple dual-goal linear programming model that manages Taupō water levels on a daily time step, optimised toward (i) hydro power income and (ii) water level in the optimal zone. The model serves as an illustration only but the approach is readily capable of being expanded to a full model that includes further goals and constraints.

text: Toward multi-objective optimisation for Lake Taupo water level managment A multi-goal optimisation strategy may provide a basis for Lake Taupō water management. This involves defining an agreed ‘optimal zone’ of lake levels which are away from both high and low levels. The aim of water releases to the Waikato River would be to maximise the duration that lake levels are within the optimal zone, while also seeking to meet other, possibly conflicting, goals such as optimal hydro power operation.
A sense of how a multi-goal model could operate is given, by considering a simple dual-goal linear programming model that manages Taupō water levels on a daily time step, optimised toward (i) hydro power income and (ii) water level in the optimal zone. The model serves as an illustration only but the approach is readily capable of being expanded to a full model that includes further goals and constraints.

year: 2019

title: Raising Māori Student Achievement - Journeys of Success

authors: Kaumoana, Cadence

abstract: Educational success for Māori students is influenced by confidence in one’s identity, positive role models and support; and positive attitudes to learning and success.
This project asked Māori tertiary graduates about their educational experiences. Half of the participants in this study had successfully completed secondary school and the other half did not complete secondary school education. This selection of participants was selected to highlight that although some students don’t complete secondary school it is still possible to successfully pursue and complete tertiary level qualifications. The feedback given from the participants highlighted the positive factors that influenced their successful completion. From these factors recommendations have been developed to support Māori student success. The objective of this study is to encourage the development of increased self-confidence for Māori rangatahi and to promote the continuation of lifelong learning.
When Māori students are supported both at school and in the home they are more likely to achieve educational success, particularly at secondary school level. Similarly, at tertiary level study; students who graduate with a completed degree qualification are likely to have had positive support and successful role models, they are likely to be secure within their own identity and wh!nau network. Māori students that successfully complete tertiary study are more likely to have positive attitudes to learning and to achieving; knowing how to access support and feeling confident in their efforts.
The key to this study is the link between successful completion of secondary school and the follow-on to successful tertiary study. When Māori students are supported appropriately in the development of their identity their confidence soon follows. This support would ideally come from wh!nau in the home and the school. When Māori students are confident in their learning journeys through high levels of confidence in identity they are more likely to persevere under pressure and despite setbacks.
Influencing factors to developing self-confidence for Māori students include awareness of Te Reo Māori and Tikanga Māori, responsibility at home, responsibility at school and the positive influence of role models. The study then concludes by providing recommendations for learners, educators and wh!nau to support the educational achievement of their tamariki.

text: Raising Māori Student Achievement - Journeys of Success Educational success for Māori students is influenced by confidence in one’s identity, positive role models and support; and positive attitudes to learning and success.
This project asked Māori tertiary graduates about their educational experiences. Half of the participants in this study had successfully completed secondary school and the other half did not complete secondary school education. This selection of participants was selected to highlight that although some students don’t complete secondary school it is still possible to successfully pursue and complete tertiary level qualifications. The feedback given from the participants highlighted the positive factors that influenced their successful completion. From these factors recommendations have been developed to support Māori student success. The objective of this study is to encourage the development of increased self-confidence for Māori rangatahi and to promote the continuation of lifelong learning.
When Māori students are supported both at school and in the home they are more likely to achieve educational success, particularly at secondary school level. Similarly, at tertiary level study; students who graduate with a completed degree qualification are likely to have had positive support and successful role models, they are likely to be secure within their own identity and wh!nau network. Māori students that successfully complete tertiary study are more likely to have positive attitudes to learning and to achieving; knowing how to access support and feeling confident in their efforts.
The key to this study is the link between successful completion of secondary school and the follow-on to successful tertiary study. When Māori students are supported appropriately in the development of their identity their confidence soon follows. This support would ideally come from wh!nau in the home and the school. When Māori students are confident in their learning journeys through high levels of confidence in identity they are more likely to persevere under pressure and despite setbacks.
Influencing factors to developing self-confidence for Māori students include awareness of Te Reo Māori and Tikanga Māori, responsibility at home, responsibility at school and the positive influence of role models. The study then concludes by providing recommendations for learners, educators and wh!nau to support the educational achievement of their tamariki.

year: 2013