title: Learning to use operational advice

authors: Fürnkranz, Johannes

subjects: computer science

abstract: We address the problem of advice-taking in a given domain, in particular for building a game-playing program. Our approach to solving it strives for the application of machine learning techniques throughout, i.e. for avoiding knowledge elicitation by any other means as much as possible. In particular, we build upon existing work on the operationalization of advice by machine and assume that advice is already available in operational form. The relative importance of this advice is, however, not yet known can therefore not be utilized well by a program. This paper presents an approach to determine the relative importance for a given situation through reinforcement learning. We implemented this approach for the game of Hearts and gathered some empirical evidence on its usefulness through experiments. The results show that the programs built according to our approach learned to make good use of the given operational advice.

text: Learning to use operational advice We address the problem of advice-taking in a given domain, in particular for building a game-playing program. Our approach to solving it strives for the application of machine learning techniques throughout, i.e. for avoiding knowledge elicitation by any other means as much as possible. In particular, we build upon existing work on the operationalization of advice by machine and assume that advice is already available in operational form. The relative importance of this advice is, however, not yet known can therefore not be utilized well by a program. This paper presents an approach to determine the relative importance for a given situation through reinforcement learning. We implemented this approach for the game of Hearts and gathered some empirical evidence on its usefulness through experiments. The results show that the programs built according to our approach learned to make good use of the given operational advice.

year: 2000

title: Light attenuation characteristics of glacially-fed lakes

authors: Rose, Kevin

abstract: Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400–700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems.

text: Light attenuation characteristics of glacially-fed lakes Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400–700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems.

year: 2014

title: Echoed silencing in Te Whare/Tangata

authors: Lewis, Cassandra Louise Terauhina

subjects: Mana Wāhine

abstract: Wāhine Māori voices are suppressed due to multiple intersecting factors in Aotearoa which negatively impact our lived realities. The aim of this thesis is to foreground wāhine voice and identity within a settler colonial housing system. The current ‘housing crisis’ has been an issue of interest in academia focusing on housing insecurity, homelessness and neoliberalism. Additionally, the criminalisation of Māori has been explored by scholars to a similar extent, especially the pipelining of Māori into incarceration and precarity through policing and surveillance strategies. However, how the criminal justice system and the housing systems interact is scarcely investigated in Aotearoa, and moreover, has not been examined through a Mana wāhine theoretical framework. Mana Wāhine scholars have long critiqued colonisation and the accompanying practices, ideologies and discourses of difference that misrepresent wāhine as the ‘savage other’. How wāhine Māori are constructed through political discourse and factors leading to the silencing of wāhine are at the forefront of this inquiry and moreover, wāhine resistance, survival and aspirations while navigating a discriminatory housing system is examined.

Political and Western discourse contributes to the criminalisation and deficit framing of wāhine as the ‘undeserving poor’ and ‘criminal other’ which subsequently silences wāhine and encourages discriminatory practices. This thesis contends that the channelling of wāhine Māori into a precarious population, the criminalisation of wāhine Māori, and the colonial discourses surrounding wāhine interact together and create barriers to wāhine Māori access to housing. An analysis of housing discourse, alongside wāhine perspectives provides a counter-narrative of the lived reality and voice from wāhine who reside in a predominantly precarious and Māori populated area. The findings show cases of surveillance, discrimination, social policing and steering wāhine Māori into unhealthy living conditions, however, wāhine were also creative in their practices of resistance and survivance.

text: Echoed silencing in Te Whare/Tangata Wāhine Māori voices are suppressed due to multiple intersecting factors in Aotearoa which negatively impact our lived realities. The aim of this thesis is to foreground wāhine voice and identity within a settler colonial housing system. The current ‘housing crisis’ has been an issue of interest in academia focusing on housing insecurity, homelessness and neoliberalism. Additionally, the criminalisation of Māori has been explored by scholars to a similar extent, especially the pipelining of Māori into incarceration and precarity through policing and surveillance strategies. However, how the criminal justice system and the housing systems interact is scarcely investigated in Aotearoa, and moreover, has not been examined through a Mana wāhine theoretical framework. Mana Wāhine scholars have long critiqued colonisation and the accompanying practices, ideologies and discourses of difference that misrepresent wāhine as the ‘savage other’. How wāhine Māori are constructed through political discourse and factors leading to the silencing of wāhine are at the forefront of this inquiry and moreover, wāhine resistance, survival and aspirations while navigating a discriminatory housing system is examined.

Political and Western discourse contributes to the criminalisation and deficit framing of wāhine as the ‘undeserving poor’ and ‘criminal other’ which subsequently silences wāhine and encourages discriminatory practices. This thesis contends that the channelling of wāhine Māori into a precarious population, the criminalisation of wāhine Māori, and the colonial discourses surrounding wāhine interact together and create barriers to wāhine Māori access to housing. An analysis of housing discourse, alongside wāhine perspectives provides a counter-narrative of the lived reality and voice from wāhine who reside in a predominantly precarious and Māori populated area. The findings show cases of surveillance, discrimination, social policing and steering wāhine Māori into unhealthy living conditions, however, wāhine were also creative in their practices of resistance and survivance.

year: 2021