title: Leaching and uptake of nitrogen, and pasture production, associated with irrigation of treated wastewater, Taupō, New Zealand

authors: Telfer, Erin Isobel Charlotte

subjects: Wastewater

abstract: Secondary-treated wastewater from Taupō Township is irrigated onto perennial ryegrass (Lolium perenne) which is harvested and removed from the View Road wastewater treatment site. To determine the fate of the applied wastewater nitrogen, 48 undisturbed barrel lysimeters (30 cm diameter x 43 cm depth) were installed throughout 29 hectares. Centre pivot travelling irrigators were programmed to vary in speed to provide target wastewater application rates of about 0, 450, 550 and 650 kg N ha⁻¹yr⁻¹.
The targeted application treatments were not achieved, with the achieved nitrogen loading rates grouped into a low treatment (286 - 380 kg N ha⁻¹yr⁻¹), a medium treatment (380 - 445 kg N ha⁻¹yr⁻¹), and a high treatment (445 - 567 kg N ha⁻¹yr⁻¹). Nitrogen input in control sectors was assumed to be 5 kg N/ha/yr from atmospheric nitrogen deposition.
A mean of 4 to 6% of the applied nitrogen was leached. The mean amount of nitrogen leached from the high treatment (28.6 ± 10.1 kg N ha⁻¹yr⁻¹) was higher (P < 0.05) than from the low treatment (12.7 ± 4.2 kg N ha⁻¹yr⁻¹). The medium treatment (16.0 ± 7.2 kg N ha⁻¹yr⁻¹) was not significantly different than the low treatment or the high treatment. The mean amount of nitrogen leached from the control treatment was 2.8 ± 0.6 kg N ha⁻¹yr⁻¹. Nitrogen leaching that occurred in the high application treatment was below the consented limit of 30 kg N ha⁻¹yr⁻¹.
A mean of 79 to 100% of the applied nitrogen was removed by pasture. There were no significant differences in pasture dry matter production, or nitrogen removal, between the low treatment (13 922 ± 1196 kg DM ha⁻¹yr⁻¹and 341 ± 25 kg N ha⁻¹yr⁻¹), the medium treatment (13 543 ± 1475 kg DM ha⁻¹yr⁻¹ and 360 ± 51 kg N ha⁻¹yr⁻¹), and the high treatment (15 285 ± 1919 kg DM ha⁻¹yr⁻¹ and 385 ± 43 kg N ha⁻¹yr⁻¹). Pasture production was higher (P < 0.001) in irrigated pastures (mean of all irrigated treatments, 14 250 ± 349 kg DM ha⁻¹yr⁻¹) than unirrigated controls (5300 ± 839 kg DM ha⁻¹yr⁻¹).
A mean of -4 to 16% of the applied wastewater nitrogen was unaccounted for. The majority of unrecovered nitrogen was presumed to be volatilised with lower potential for denitrification and soil storage.
A second experiment was undertaken to determine whether a five week or a ten week harvesting frequency would result in greater pasture production and nitrogen removal. During the ten month trial, 265 kg N ha⁻¹ of wastewater nitrogen was irrigated and pasture plots (1 m x 1 m) were cut with a mower. Nitrogen removal and pasture production were higher (P < 0.05) with a five week harvesting interval (8231 ± 186 kg DM ha⁻¹ and 250 ± 5 kg N ha⁻¹) than a ten week harvesting interval (7354 ± 67 kg DM ha⁻¹ and 191 ± 3 kg N ha⁻¹). Harvesting at five week intervals during late-November to May (late-spring to late-autumn) and ten week intervals from May until early-November (late-autumn to mid-spring) is recommended to maximise both pasture production and nitrogen removal, while minimising harvesting costs.

text: Leaching and uptake of nitrogen, and pasture production, associated with irrigation of treated wastewater, Taupō, New Zealand Secondary-treated wastewater from Taupō Township is irrigated onto perennial ryegrass (Lolium perenne) which is harvested and removed from the View Road wastewater treatment site. To determine the fate of the applied wastewater nitrogen, 48 undisturbed barrel lysimeters (30 cm diameter x 43 cm depth) were installed throughout 29 hectares. Centre pivot travelling irrigators were programmed to vary in speed to provide target wastewater application rates of about 0, 450, 550 and 650 kg N ha⁻¹yr⁻¹.
The targeted application treatments were not achieved, with the achieved nitrogen loading rates grouped into a low treatment (286 - 380 kg N ha⁻¹yr⁻¹), a medium treatment (380 - 445 kg N ha⁻¹yr⁻¹), and a high treatment (445 - 567 kg N ha⁻¹yr⁻¹). Nitrogen input in control sectors was assumed to be 5 kg N/ha/yr from atmospheric nitrogen deposition.
A mean of 4 to 6% of the applied nitrogen was leached. The mean amount of nitrogen leached from the high treatment (28.6 ± 10.1 kg N ha⁻¹yr⁻¹) was higher (P < 0.05) than from the low treatment (12.7 ± 4.2 kg N ha⁻¹yr⁻¹). The medium treatment (16.0 ± 7.2 kg N ha⁻¹yr⁻¹) was not significantly different than the low treatment or the high treatment. The mean amount of nitrogen leached from the control treatment was 2.8 ± 0.6 kg N ha⁻¹yr⁻¹. Nitrogen leaching that occurred in the high application treatment was below the consented limit of 30 kg N ha⁻¹yr⁻¹.
A mean of 79 to 100% of the applied nitrogen was removed by pasture. There were no significant differences in pasture dry matter production, or nitrogen removal, between the low treatment (13 922 ± 1196 kg DM ha⁻¹yr⁻¹and 341 ± 25 kg N ha⁻¹yr⁻¹), the medium treatment (13 543 ± 1475 kg DM ha⁻¹yr⁻¹ and 360 ± 51 kg N ha⁻¹yr⁻¹), and the high treatment (15 285 ± 1919 kg DM ha⁻¹yr⁻¹ and 385 ± 43 kg N ha⁻¹yr⁻¹). Pasture production was higher (P < 0.001) in irrigated pastures (mean of all irrigated treatments, 14 250 ± 349 kg DM ha⁻¹yr⁻¹) than unirrigated controls (5300 ± 839 kg DM ha⁻¹yr⁻¹).
A mean of -4 to 16% of the applied wastewater nitrogen was unaccounted for. The majority of unrecovered nitrogen was presumed to be volatilised with lower potential for denitrification and soil storage.
A second experiment was undertaken to determine whether a five week or a ten week harvesting frequency would result in greater pasture production and nitrogen removal. During the ten month trial, 265 kg N ha⁻¹ of wastewater nitrogen was irrigated and pasture plots (1 m x 1 m) were cut with a mower. Nitrogen removal and pasture production were higher (P < 0.05) with a five week harvesting interval (8231 ± 186 kg DM ha⁻¹ and 250 ± 5 kg N ha⁻¹) than a ten week harvesting interval (7354 ± 67 kg DM ha⁻¹ and 191 ± 3 kg N ha⁻¹). Harvesting at five week intervals during late-November to May (late-spring to late-autumn) and ten week intervals from May until early-November (late-autumn to mid-spring) is recommended to maximise both pasture production and nitrogen removal, while minimising harvesting costs.

year: 2013

title: Scalable Multi-label Classification

authors: Read, Jesse

subjects: multi-label

abstract: Multi-label classification is relevant to many domains, such as text, image and other media, and bioinformatics. Researchers have already noticed that in multi-label data, correlations exist between labels, and a variety of approaches, drawing inspiration from many spheres of machine learning, have been able to model these correlations. However, data sources from the real world are growing ever larger and the multi-label task is particularly sensitive to this due to the complexity associated with multiple labels and the correlations between them. Consequently, many methods do not scale up to large problems. This thesis deals with scalable multi-label classification: methods which exhibit high predictive performance, but are also able to scale up to larger problems. The first major contribution is the pruned sets method, which is able to model label correlations directly for high predictive performance, but reduces overfitting and complexity over related methods by pruning and subsampling label sets, and can thus scale up to larger datasets. The second major contribution is the classifier chains method, which models correlations with a chain of binary classifiers. The use of binary models allows for scalability to even larger datasets. Pruned sets and classifier chains are robust with respect to both the variety and scale of data that they can deal with, and can be incorporated into other methods. In an ensemble scheme, these methods are able to compete with state-of-the-art methods in terms of predictive performance as well as scale up to large datasets of hundreds of thousands of training examples. This thesis also puts a special emphasis on multi-label evaluation; introducing a new evaluation measure and studying threshold calibration. With one of the largest and most varied collections of multi-label datasets in the literature, extensive experimental evaluation shows the advantage of these methods, both in terms of predictive performance, and computational efficiency and scalability.

text: Scalable Multi-label Classification Multi-label classification is relevant to many domains, such as text, image and other media, and bioinformatics. Researchers have already noticed that in multi-label data, correlations exist between labels, and a variety of approaches, drawing inspiration from many spheres of machine learning, have been able to model these correlations. However, data sources from the real world are growing ever larger and the multi-label task is particularly sensitive to this due to the complexity associated with multiple labels and the correlations between them. Consequently, many methods do not scale up to large problems. This thesis deals with scalable multi-label classification: methods which exhibit high predictive performance, but are also able to scale up to larger problems. The first major contribution is the pruned sets method, which is able to model label correlations directly for high predictive performance, but reduces overfitting and complexity over related methods by pruning and subsampling label sets, and can thus scale up to larger datasets. The second major contribution is the classifier chains method, which models correlations with a chain of binary classifiers. The use of binary models allows for scalability to even larger datasets. Pruned sets and classifier chains are robust with respect to both the variety and scale of data that they can deal with, and can be incorporated into other methods. In an ensemble scheme, these methods are able to compete with state-of-the-art methods in terms of predictive performance as well as scale up to large datasets of hundreds of thousands of training examples. This thesis also puts a special emphasis on multi-label evaluation; introducing a new evaluation measure and studying threshold calibration. With one of the largest and most varied collections of multi-label datasets in the literature, extensive experimental evaluation shows the advantage of these methods, both in terms of predictive performance, and computational efficiency and scalability.

year: 2010

title: A Portfolio of Compositions

authors: Dobson, Elizabeth Jane

subjects: music

abstract: The pieces in this portfolio cover a wide range of methods and styles - from work for a single vocalising percussionist, to singing bowl and electronics and a work for full orchestra. The aim of this portfolio is to demonstrate my technical and musical proficiency as well as to give an overview of my personal composing philosophy and style.
The portfolio opens with a work for orchestra, A Study in Scarlet. It differs from my previous orchestral works and is based on a musical code of Sir Arthur Conan Doyle's book, titled A Study in Scarlet. This was read in the 2009 Todd/ NSZO Young Composer Readings. The second work is .manatu.. It features tinkly piano, wind chimes and ethnic instrumentalists in a chamber ensemble to create a musical sound world. This was written for and premiered at Bang on a Can's summer music festival in Massachusetts 2009. The piano work .ātanga. is an adaptation of .manatu. for solo pianist and was written for the Dame Malvina Major Foundations Showcase Concert in New Plymouth. This adaptation proved to be a worthwhile exercise in efficient use of music material. Wrong Number is a Janet Frame poem set for soprano and real-time effect processing of audio. Confessions - Part I and II, for solo violin and string orchestra is based on the Fibonacci series and explores my love for string sonorities. Sand Song was written for a friend who asked me to set a poem she wrote. Here I demonstrate my love for setting text and voice to say something beautiful and precise. This song now stands as a eulogy for her Father. Parihaka, for vocalising percussionist, is a setting of Apirana Taylor's poem Parihaka and was written for Australian performer Louise Devenish. I explore further in the realm of live acoustic and electroacoustic music with Orison a piece I wrote for myself to perform live with singing bowl and Ableton Live. Finally The Headlines Today for five improvising musicians explores the music of shouting and the vernacular of place.

text: A Portfolio of Compositions The pieces in this portfolio cover a wide range of methods and styles - from work for a single vocalising percussionist, to singing bowl and electronics and a work for full orchestra. The aim of this portfolio is to demonstrate my technical and musical proficiency as well as to give an overview of my personal composing philosophy and style.
The portfolio opens with a work for orchestra, A Study in Scarlet. It differs from my previous orchestral works and is based on a musical code of Sir Arthur Conan Doyle's book, titled A Study in Scarlet. This was read in the 2009 Todd/ NSZO Young Composer Readings. The second work is .manatu.. It features tinkly piano, wind chimes and ethnic instrumentalists in a chamber ensemble to create a musical sound world. This was written for and premiered at Bang on a Can's summer music festival in Massachusetts 2009. The piano work .ātanga. is an adaptation of .manatu. for solo pianist and was written for the Dame Malvina Major Foundations Showcase Concert in New Plymouth. This adaptation proved to be a worthwhile exercise in efficient use of music material. Wrong Number is a Janet Frame poem set for soprano and real-time effect processing of audio. Confessions - Part I and II, for solo violin and string orchestra is based on the Fibonacci series and explores my love for string sonorities. Sand Song was written for a friend who asked me to set a poem she wrote. Here I demonstrate my love for setting text and voice to say something beautiful and precise. This song now stands as a eulogy for her Father. Parihaka, for vocalising percussionist, is a setting of Apirana Taylor's poem Parihaka and was written for Australian performer Louise Devenish. I explore further in the realm of live acoustic and electroacoustic music with Orison a piece I wrote for myself to perform live with singing bowl and Ableton Live. Finally The Headlines Today for five improvising musicians explores the music of shouting and the vernacular of place.

year: 2010