title: Extracting the MESA SR4000 Calibrations

authors: Charleston, Sean A.

subjects: Science & Technology

abstract: Time-of-flight range imaging cameras are capable of acquiring depth images of a scene. Some algorithms require these cameras to be run in `raw mode', where any calibrations from the off-the-shelf manufacturers are lost. The calibration of the MESA SR4000 is herein investigated, with an attempt to reconstruct the full calibration. Possession of the factory calibration enables calibrated data to be acquired and manipulated even in “raw mode.” This work is motivated by the problem of motion correction, in which the calibration must be separated into component parts to be applied at different stages in the algorithm. There are also other applications, in which multiple frequencies are required, such as multipath interference correction. The other frequencies can be calibrated in a similar way, using the factory calibration as a base. A novel technique for capturing the calibration data is described; a retro-reflector is used on a moving platform, which acts as a point source at a distance, resulting in planar waves on the sensor. A number of calibrations are retrieved from the camera, and are then modelled and compared to the factory calibration. When comparing the factory calibration to both the “raw mode” data, and the calibration described herein, a root mean squared error improvement of 51:3mm was seen, with a standard deviation improvement of 34:9mm. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

text: Extracting the MESA SR4000 Calibrations Time-of-flight range imaging cameras are capable of acquiring depth images of a scene. Some algorithms require these cameras to be run in `raw mode', where any calibrations from the off-the-shelf manufacturers are lost. The calibration of the MESA SR4000 is herein investigated, with an attempt to reconstruct the full calibration. Possession of the factory calibration enables calibrated data to be acquired and manipulated even in “raw mode.” This work is motivated by the problem of motion correction, in which the calibration must be separated into component parts to be applied at different stages in the algorithm. There are also other applications, in which multiple frequencies are required, such as multipath interference correction. The other frequencies can be calibrated in a similar way, using the factory calibration as a base. A novel technique for capturing the calibration data is described; a retro-reflector is used on a moving platform, which acts as a point source at a distance, resulting in planar waves on the sensor. A number of calibrations are retrieved from the camera, and are then modelled and compared to the factory calibration. When comparing the factory calibration to both the “raw mode” data, and the calibration described herein, a root mean squared error improvement of 51:3mm was seen, with a standard deviation improvement of 34:9mm. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

year: 2015

title: The effects of a high-school poetry competition: A case-study

authors: Locke, Terry

subjects: poetry

abstract: This case-study explores the effects of a school-wide writing competition and the implementation of a poetry-writing unit across all junior English classes in a rural New Zealand school. Teacher interview data were thematically analysed using a social constructionist lens. Results highlight the varied strategies adopted by teachers, while indicating commonalities of approach. The competition proved a spur to teachers, challenging them to address matters of activity sequencing and design, and their classroom roles. Somewhat unexpectedly, the competition was found to be an extrinsic motivator that worked synergistically with teachers’ choices of learning activities and approaches to motivate students, and helped produce whole-class, collective efficacy effects.

text: The effects of a high-school poetry competition: A case-study This case-study explores the effects of a school-wide writing competition and the implementation of a poetry-writing unit across all junior English classes in a rural New Zealand school. Teacher interview data were thematically analysed using a social constructionist lens. Results highlight the varied strategies adopted by teachers, while indicating commonalities of approach. The competition proved a spur to teachers, challenging them to address matters of activity sequencing and design, and their classroom roles. Somewhat unexpectedly, the competition was found to be an extrinsic motivator that worked synergistically with teachers’ choices of learning activities and approaches to motivate students, and helped produce whole-class, collective efficacy effects.

year: 2013

title: 'Kōrero Tuku Iho': Reconfiguring Oral History and Oral Tradition

authors: Mahuika, Nepia

subjects: History

abstract: The studies of oral history and oral tradition each have their own distinctive bodies of literature and preferred methodologies, yet share significant overlaps that make them difficult to differentiate. For many indigenous peoples, oral histories and traditions are key to their their past, present, and future lives, and are rarely considered separate. This thesis examines the differences and similarities between the studies of oral history and oral tradition. It explores how these areas of research converge and diverge in form, politics, practice, and theory, and the extent to which they resonate within a specific ‘indigenous’ context and community.
The thesis draws on the life narrative interviews of four generations of Ngāti Porou descendents, the second largest tribal group in New Zealand, whose home boundaries extend from Potikirua in the north to Te Toka-a-Taiau in the south on the East Coast of the North Island. Drawing on these voices, this study offers a commentary on the form and nature of oral traditions and histories from an indigenous perspective, and explores the ways they converge and depart from ‘international’ understandings. An exploration of these intersections offers insights to the ways oral history and oral traditions might be reconsidered as distinctive fields of study. Reconfigured through an indigenous frame of reference, this thesis challenges scholars of both oral history and oral tradition to expand their conceptions. Likewise, it urges indigenous scholars to consider more deeply the work of oral historians and oral traditionalists to further enhance their scholarship. Moreover, this thesis revisits the intellectual and conceptual territory that names and claims oral history and oral tradition, and invites all those who work in these areas to develop a more extensive comprehension of the interconnections that exist between each area of study.

text: 'Kōrero Tuku Iho': Reconfiguring Oral History and Oral Tradition The studies of oral history and oral tradition each have their own distinctive bodies of literature and preferred methodologies, yet share significant overlaps that make them difficult to differentiate. For many indigenous peoples, oral histories and traditions are key to their their past, present, and future lives, and are rarely considered separate. This thesis examines the differences and similarities between the studies of oral history and oral tradition. It explores how these areas of research converge and diverge in form, politics, practice, and theory, and the extent to which they resonate within a specific ‘indigenous’ context and community.
The thesis draws on the life narrative interviews of four generations of Ngāti Porou descendents, the second largest tribal group in New Zealand, whose home boundaries extend from Potikirua in the north to Te Toka-a-Taiau in the south on the East Coast of the North Island. Drawing on these voices, this study offers a commentary on the form and nature of oral traditions and histories from an indigenous perspective, and explores the ways they converge and depart from ‘international’ understandings. An exploration of these intersections offers insights to the ways oral history and oral traditions might be reconsidered as distinctive fields of study. Reconfigured through an indigenous frame of reference, this thesis challenges scholars of both oral history and oral tradition to expand their conceptions. Likewise, it urges indigenous scholars to consider more deeply the work of oral historians and oral traditionalists to further enhance their scholarship. Moreover, this thesis revisits the intellectual and conceptual territory that names and claims oral history and oral tradition, and invites all those who work in these areas to develop a more extensive comprehension of the interconnections that exist between each area of study.

year: 2012