title: Improved linearity using harmonic error rejection in a full-field range imaging system

authors: Payne, Andrew D.

subjects: phase detection

abstract: Full field range imaging cameras are used to simultaneously measure the distance for every pixel in a given scene using an intensity modulated illumination source and a gain modulated receiver array. The light is reflected from an object in the scene, and the modulation envelope experiences a phase shift proportional to the target distance. Ideally the waveforms are sinusoidal, allowing the phase, and hence object range, to be determined from four measurements using an arctangent function. In practice these waveforms are often not perfectly sinusoidal, and in some cases square waveforms are instead used to simplify the electronic drive requirements. The waveforms therefore commonly contain odd harmonics which contribute a nonlinear error to the phase determination, and therefore an error in the range measurement. We have developed a unique sampling method to cancel the effect of these harmonics, with the results showing an order of magnitude improvement in the measurement linearity without the need for calibration or lookup tables, while the acquisition time remains unchanged. The technique can be applied to existing range imaging systems without having to change or modify the complex illumination or sensor systems, instead only requiring a change to the signal generation and timing electronics.

text: Improved linearity using harmonic error rejection in a full-field range imaging system Full field range imaging cameras are used to simultaneously measure the distance for every pixel in a given scene using an intensity modulated illumination source and a gain modulated receiver array. The light is reflected from an object in the scene, and the modulation envelope experiences a phase shift proportional to the target distance. Ideally the waveforms are sinusoidal, allowing the phase, and hence object range, to be determined from four measurements using an arctangent function. In practice these waveforms are often not perfectly sinusoidal, and in some cases square waveforms are instead used to simplify the electronic drive requirements. The waveforms therefore commonly contain odd harmonics which contribute a nonlinear error to the phase determination, and therefore an error in the range measurement. We have developed a unique sampling method to cancel the effect of these harmonics, with the results showing an order of magnitude improvement in the measurement linearity without the need for calibration or lookup tables, while the acquisition time remains unchanged. The technique can be applied to existing range imaging systems without having to change or modify the complex illumination or sensor systems, instead only requiring a change to the signal generation and timing electronics.

year: 2008

title: Competitive interactions in a dairy pasture containing paspalum (Paspalum dilatatum Poir,) following the introduction of ryegrass (Lolium perenne L.)

authors: Thom, Errol

abstract: A series of trials investigated the contribution of introduced grasses (Lolium perenne and Bromus catharticus) to seasonal production of a high yielding dairy sward containing paspalum (Paspalum dilatatum). The persistence of the introduced species was also determined.
Autumn overdrilling improved (<500 kg DM/ha) herbage production in the following winter/spring and autumn, but thereafter differences between drilled and undrilled swards disappeared. The monitoring of individual plants showed that there were high summer losses of introduced plants; up to 56% were lost by one year after drilling. The contribution of Bromus catharticus to herbage mass was less than that for Lolium perenne, as summer losses of the former plants were higher than for the latter because of increased susceptibility to direct ‘animal effects’ (eg. ‘pulling’). Bromus catharticus was therefore excluded from subsequent experiments. Summer growth of introduced plants was more restricted when they were closely associated with established paspalum than with other resident species, and large plants had better summer persistence than small plants. 
Manipulation of the light environment of the introduced ryegrass plants by regular clipping (10 mm stubble) of surrounding resident herbage markedly improved their ability to survive summer management and environmental stresses. The introduced plants were able to attain a large average size (20 to 50 tillers per plant) before the onset of summer.
Summer losses of introduced plants were higher when grazed at a short (2-3 week) rather than a long (3-4 week) interval and if paspalum was a close neighbour. About 20% of total losses were related to direct cow damage, namely, severe grazing, ‘pulling’, dung and urine deposition, and trampling. The latter effects may be important where stocking densities are high. Other treatments such as late-winter/early-spring application of nitrogen fertiliser and irrigation during summer/autumn, failed to improve persistence of introduced ryegrass.
One of the various ecological strategies that gives paspalum a competitive advantage over ryegrass is its ability to accumulate large reserves of carbohydrate. Measurement of nonstructural carbohydrate accumulated in above-and below-ground organs indicated that these reached a maximum for both species towards the end of the period of their most active growth. At this time the nonstructural carbohydrate level for paspalum at 1050 kg/ha, was four times greater than that for ryegrass. 
Possible practical methods for improving the persistence of ryegrass introduced into established swards are discussed.

text: Competitive interactions in a dairy pasture containing paspalum (Paspalum dilatatum Poir,) following the introduction of ryegrass (Lolium perenne L.) A series of trials investigated the contribution of introduced grasses (Lolium perenne and Bromus catharticus) to seasonal production of a high yielding dairy sward containing paspalum (Paspalum dilatatum). The persistence of the introduced species was also determined.
Autumn overdrilling improved (<500 kg DM/ha) herbage production in the following winter/spring and autumn, but thereafter differences between drilled and undrilled swards disappeared. The monitoring of individual plants showed that there were high summer losses of introduced plants; up to 56% were lost by one year after drilling. The contribution of Bromus catharticus to herbage mass was less than that for Lolium perenne, as summer losses of the former plants were higher than for the latter because of increased susceptibility to direct ‘animal effects’ (eg. ‘pulling’). Bromus catharticus was therefore excluded from subsequent experiments. Summer growth of introduced plants was more restricted when they were closely associated with established paspalum than with other resident species, and large plants had better summer persistence than small plants. 
Manipulation of the light environment of the introduced ryegrass plants by regular clipping (10 mm stubble) of surrounding resident herbage markedly improved their ability to survive summer management and environmental stresses. The introduced plants were able to attain a large average size (20 to 50 tillers per plant) before the onset of summer.
Summer losses of introduced plants were higher when grazed at a short (2-3 week) rather than a long (3-4 week) interval and if paspalum was a close neighbour. About 20% of total losses were related to direct cow damage, namely, severe grazing, ‘pulling’, dung and urine deposition, and trampling. The latter effects may be important where stocking densities are high. Other treatments such as late-winter/early-spring application of nitrogen fertiliser and irrigation during summer/autumn, failed to improve persistence of introduced ryegrass.
One of the various ecological strategies that gives paspalum a competitive advantage over ryegrass is its ability to accumulate large reserves of carbohydrate. Measurement of nonstructural carbohydrate accumulated in above-and below-ground organs indicated that these reached a maximum for both species towards the end of the period of their most active growth. At this time the nonstructural carbohydrate level for paspalum at 1050 kg/ha, was four times greater than that for ryegrass. 
Possible practical methods for improving the persistence of ryegrass introduced into established swards are discussed.

year: 1984

title: Restoring Indigneous Law and Justice Traditions

authors: Cook, Michelle Lynn

subjects: Indigenous peoples

abstract: Restoring indigenous people's law and their ability to practice their justice traditions is a fundamental aspect of non-discrimination, decolonization, self-governance, self-determination, and social justice. The critical application and interpretation of indigenous people's law has revolutionary potentiality to transform, confront, and heal multiple forms of oppression such as environmental destruction, patriarchy, and the prison/criminal justice system. The sovereign jurisgenerative (law making) power of indigenous peoples is a site of profound hope for the revitalization of indigenous law and justice traditions restores legal principles and values of sacredness, harmony, balance, and interconnectivity within human relationships and with the natural world. Revitalizing indigenous law is a way to re-construct the self and society while also finding and re-connecting to new/old ways of being human. This thesis focuses on both Navajo and Māori practices and visions of law and justice; the challenges and, successes they have faced and the hopes they have of living by their law. Indigenous peoples, their ways of being, their wisdom, laws, and philosophies, must be respected, protected, and preserved not only because they contribute to humanity's richness and cultural diversity but also because they are living examples of  a more just, dignified, and ecologically sustainable society, which can serve all humanity.

text: Restoring Indigneous Law and Justice Traditions Restoring indigenous people's law and their ability to practice their justice traditions is a fundamental aspect of non-discrimination, decolonization, self-governance, self-determination, and social justice. The critical application and interpretation of indigenous people's law has revolutionary potentiality to transform, confront, and heal multiple forms of oppression such as environmental destruction, patriarchy, and the prison/criminal justice system. The sovereign jurisgenerative (law making) power of indigenous peoples is a site of profound hope for the revitalization of indigenous law and justice traditions restores legal principles and values of sacredness, harmony, balance, and interconnectivity within human relationships and with the natural world. Revitalizing indigenous law is a way to re-construct the self and society while also finding and re-connecting to new/old ways of being human. This thesis focuses on both Navajo and Māori practices and visions of law and justice; the challenges and, successes they have faced and the hopes they have of living by their law. Indigenous peoples, their ways of being, their wisdom, laws, and philosophies, must be respected, protected, and preserved not only because they contribute to humanity's richness and cultural diversity but also because they are living examples of  a more just, dignified, and ecologically sustainable society, which can serve all humanity.

year: 2010