title: Beyond 'just' flood risk management: the potential for-and limits to-alleviating flood disadvantage

authors: O'Hare, Paul

subjects: Science & Technology

abstract: The threat of flooding poses a considerable challenge for justice. Not only are more citizens becoming exposed to risk, but they are expected to play increasingly active roles in flood risk management. However, until recently, few efforts have charted broader understandings of disadvantage relating to flood risk exposure. Drawing upon social science scholarship that has long been sensitive to concerns related to justice, we deploy and develop the notion of flood disadvantage as a means to assess the challenges to more ‘just’ flood risk management. We contend that the concept of flood disadvantage offers a useful lens to appreciate the constraints of technical approaches to flood risk management, in particular, its limited ability to incorporate complex social elements such as how individuals have differing vulnerabilities and sensitivities to flooding and uneven abilities to engage with risk agendas. The notion highlights the compounding interactions between flooding and other social disadvantages across multiple public policy areas and scales. We argue a fuller acknowledgement of the socio-spatial-temporal dimensions of intersecting disadvantages can help sensitise technical risk analyses that tend to see people and communities as homogeneous entities in a given spatiality. In doing so we can better reveal why some individuals or communities are more vulnerable to disasters or are slower to recover than others. Finally, we outline the challenges in turning more ‘just’ flood risk management from an abstract notion into one that could inform future practice.

text: Beyond 'just' flood risk management: the potential for-and limits to-alleviating flood disadvantage The threat of flooding poses a considerable challenge for justice. Not only are more citizens becoming exposed to risk, but they are expected to play increasingly active roles in flood risk management. However, until recently, few efforts have charted broader understandings of disadvantage relating to flood risk exposure. Drawing upon social science scholarship that has long been sensitive to concerns related to justice, we deploy and develop the notion of flood disadvantage as a means to assess the challenges to more ‘just’ flood risk management. We contend that the concept of flood disadvantage offers a useful lens to appreciate the constraints of technical approaches to flood risk management, in particular, its limited ability to incorporate complex social elements such as how individuals have differing vulnerabilities and sensitivities to flooding and uneven abilities to engage with risk agendas. The notion highlights the compounding interactions between flooding and other social disadvantages across multiple public policy areas and scales. We argue a fuller acknowledgement of the socio-spatial-temporal dimensions of intersecting disadvantages can help sensitise technical risk analyses that tend to see people and communities as homogeneous entities in a given spatiality. In doing so we can better reveal why some individuals or communities are more vulnerable to disasters or are slower to recover than others. Finally, we outline the challenges in turning more ‘just’ flood risk management from an abstract notion into one that could inform future practice.

year: 2018

title: Development of a Full-Field Time-of-Flight Range Imaging System

authors: Payne, Andrew D.

subjects: Range Imaging

abstract: A full-field, time-of-flight, image ranging system or  3D camera  has been developed from a proof-of-principle to a working prototype stage, capable of determining the intensity and range for every pixel in a scene. The system can be adapted to the requirements of various applications, producing high precision range measurements with sub-millimetre resolution, or high speed measurements at video frame rates. Parallel data acquisition at each pixel provides high spatial resolution independent of the operating speed.
The range imaging system uses a heterodyne technique to indirectly measure time of flight. Laser diodes with highly diverging beams are intensity modulated at radio frequencies and used to illuminate the scene. Reflected light is focused on to an image intensifier used as a high speed optical shutter, which is modulated at a slightly different frequency to that of the laser source. The output from the shutter is a low frequency beat signal, which is sampled by a digital video camera. Optical propagation delay is encoded into the phase of the beat signal, hence from a captured time variant intensity sequence, the beat signal phase can be measured to determine range for every pixel in the scene.
A direct digital synthesiser (DDS) is designed and constructed, capable of generating up to three outputs at frequencies beyond 100 MHz with the relative frequency stability in excess of nine orders of magnitude required to control the laser and shutter modulation. Driver circuits were also designed to modulate the image intensifier photocathode at 50 Vpp, and four laser diodes with a combined power output of 320 mW, both over a frequency range of 10-100 MHz. The DDS, laser, and image intensifier response are characterised. A unique method of measuring the image intensifier optical modulation response is developed, requiring the construction of a pico-second pulsed laser source.
This characterisation revealed deficiencies in the measured responses, which were mitigated through hardware modifications where possible. The effects of remaining imperfections, such as modulation waveform harmonics and image intensifier irising, can be calibrated and removed from the range measurements during software processing using the characterisation data. 
Finally, a digital method of generating the high frequency modulation signals using a FPGA to replace the analogue DDS is developed, providing a highly integrated solution, reducing the complexity, and enhancing flexibility. In addition, a novel modulation coding technique is developed to remove the undesirable influence of waveform harmonics from the range measurement without extending the acquisition time. When combined with a proposed modification to the laser illumination source, the digital system can enhance range measurement precision and linearity.
From this work, a flexible full-field image ranging system is successfully realised. The system is demonstrated operating in a high precision mode with sub-millimetre depth resolution, and also in a high speed mode operating at video update rates (25 fps), in both cases providing high (512 512) spatial resolution over distances of several metres.

text: Development of a Full-Field Time-of-Flight Range Imaging System A full-field, time-of-flight, image ranging system or  3D camera  has been developed from a proof-of-principle to a working prototype stage, capable of determining the intensity and range for every pixel in a scene. The system can be adapted to the requirements of various applications, producing high precision range measurements with sub-millimetre resolution, or high speed measurements at video frame rates. Parallel data acquisition at each pixel provides high spatial resolution independent of the operating speed.
The range imaging system uses a heterodyne technique to indirectly measure time of flight. Laser diodes with highly diverging beams are intensity modulated at radio frequencies and used to illuminate the scene. Reflected light is focused on to an image intensifier used as a high speed optical shutter, which is modulated at a slightly different frequency to that of the laser source. The output from the shutter is a low frequency beat signal, which is sampled by a digital video camera. Optical propagation delay is encoded into the phase of the beat signal, hence from a captured time variant intensity sequence, the beat signal phase can be measured to determine range for every pixel in the scene.
A direct digital synthesiser (DDS) is designed and constructed, capable of generating up to three outputs at frequencies beyond 100 MHz with the relative frequency stability in excess of nine orders of magnitude required to control the laser and shutter modulation. Driver circuits were also designed to modulate the image intensifier photocathode at 50 Vpp, and four laser diodes with a combined power output of 320 mW, both over a frequency range of 10-100 MHz. The DDS, laser, and image intensifier response are characterised. A unique method of measuring the image intensifier optical modulation response is developed, requiring the construction of a pico-second pulsed laser source.
This characterisation revealed deficiencies in the measured responses, which were mitigated through hardware modifications where possible. The effects of remaining imperfections, such as modulation waveform harmonics and image intensifier irising, can be calibrated and removed from the range measurements during software processing using the characterisation data. 
Finally, a digital method of generating the high frequency modulation signals using a FPGA to replace the analogue DDS is developed, providing a highly integrated solution, reducing the complexity, and enhancing flexibility. In addition, a novel modulation coding technique is developed to remove the undesirable influence of waveform harmonics from the range measurement without extending the acquisition time. When combined with a proposed modification to the laser illumination source, the digital system can enhance range measurement precision and linearity.
From this work, a flexible full-field image ranging system is successfully realised. The system is demonstrated operating in a high precision mode with sub-millimetre depth resolution, and also in a high speed mode operating at video update rates (25 fps), in both cases providing high (512 512) spatial resolution over distances of several metres.

year: 2008

title: Māori engagement with early childhood education in a low-socioeconomic area

authors: Nuri, Sinead

subjects: early childhood education

abstract: The early childhood education (ECE) options available to parents in New Zealand are many and varied. As a country New Zealand values ECE and has a high rate of engagement. However, despite a number of government initiatives targeting Māori and those from lower socio-economic areas Māori engagement remains low. This is widely acknowledged and the challenge is to not only find the reasons why but to also be responsive to the causes for low engagement.

Early learning services in New Zealand follow a curriculum that considers an holistic approach with the child at the centre of the learning. That curriculum is Te Whāriki: He whāriki mātauranga mō ngā mokopuna o Aotearoa. The curriculum recognises the potential of children and the importance of belonging in developing the whole child. 

ECE in New Zealand is important for children who are aged zero to five. It is during these early years that children will begin to develop an understanding of the world around them. The environment that children live in is important to their development and it is generally considered that those from low socio-economic areas are less likely to succeed than those from higher socio-economic areas.

This thesis investigated Māori engagement in ECE from one low socio-economic area in New Zealand using an overarching Kaupapa Māori methodology. Semi-structured interviews were held with five participants from the low socio-economic area using a case study research design. My analysis found that there were many reasons behind the parents' decisions to send their children to ECE or not. It can be concluded that Māori engagement with ECE is dependent upon parents’ early life experiences and their cultural values.

text: Māori engagement with early childhood education in a low-socioeconomic area The early childhood education (ECE) options available to parents in New Zealand are many and varied. As a country New Zealand values ECE and has a high rate of engagement. However, despite a number of government initiatives targeting Māori and those from lower socio-economic areas Māori engagement remains low. This is widely acknowledged and the challenge is to not only find the reasons why but to also be responsive to the causes for low engagement.

Early learning services in New Zealand follow a curriculum that considers an holistic approach with the child at the centre of the learning. That curriculum is Te Whāriki: He whāriki mātauranga mō ngā mokopuna o Aotearoa. The curriculum recognises the potential of children and the importance of belonging in developing the whole child. 

ECE in New Zealand is important for children who are aged zero to five. It is during these early years that children will begin to develop an understanding of the world around them. The environment that children live in is important to their development and it is generally considered that those from low socio-economic areas are less likely to succeed than those from higher socio-economic areas.

This thesis investigated Māori engagement in ECE from one low socio-economic area in New Zealand using an overarching Kaupapa Māori methodology. Semi-structured interviews were held with five participants from the low socio-economic area using a case study research design. My analysis found that there were many reasons behind the parents' decisions to send their children to ECE or not. It can be concluded that Māori engagement with ECE is dependent upon parents’ early life experiences and their cultural values.

year: 2024