title: Conditional density estimation with class probability estimators

authors: Frank, Eibe

subjects: computer science

abstract: Many regression schemes deliver a point estimate only, but often it is useful or even essential to quantify the uncertainty inherent in a prediction. If a conditional density estimate is available, then prediction intervals can be derived from it. In this paper we compare three techniques for computing conditional density estimates using a class probability estimator, where this estimator is applied to the discretized target variable and used to derive instance weights for an underlying univariate density estimator; this yields a conditional density estimate. The three density estimators we compare are: a histogram estimator that has been used previously in this context, a normal density estimator, and a kernel estimator. In our experiments, the latter two deliver better performance, both in terms of cross-validated log-likelihood and in terms of quality of the resulting prediction intervals. The empirical coverage of the intervals is close to the desired confidence level in most cases. We also include results for point estimation, as well as a comparison to Gaussian process regression and nonparametric quantile estimation.

text: Conditional density estimation with class probability estimators Many regression schemes deliver a point estimate only, but often it is useful or even essential to quantify the uncertainty inherent in a prediction. If a conditional density estimate is available, then prediction intervals can be derived from it. In this paper we compare three techniques for computing conditional density estimates using a class probability estimator, where this estimator is applied to the discretized target variable and used to derive instance weights for an underlying univariate density estimator; this yields a conditional density estimate. The three density estimators we compare are: a histogram estimator that has been used previously in this context, a normal density estimator, and a kernel estimator. In our experiments, the latter two deliver better performance, both in terms of cross-validated log-likelihood and in terms of quality of the resulting prediction intervals. The empirical coverage of the intervals is close to the desired confidence level in most cases. We also include results for point estimation, as well as a comparison to Gaussian process regression and nonparametric quantile estimation.

year: 2009

title: Identifying transition temperatures in bloodmeal-based thermoplastics using material pocket DMTA

authors: Bier, James Michael

subjects: Bioplastics

abstract: Bloodmeal can be used to manufacture thermoplastics, but requires water, urea, sodium sulphite, and sodium dodecyl sulphate to modify chain mobility. Transition temperatures of bloodmeal, modified bloodmeal, and processed bloodmeal-based thermoplastics were compared using material pocket dynamic mechanical thermal analysis. The glass transition temperature (T ɡ) of bloodmeal dropped from 493 to 263 K using only water as a plasticizer but was restored when freeze dried. Modifying bloodmeal lowered T ɡ to 193 K. This was raised by drying, but not to that of unmodified bloodmeal indicating a permanent change. Three additional transitions were identified above T ɡ, for modified bloodmeal between 300 and 480 K. These were thought to be transitions of dehydrated bulk amorphous regions, amorphous regions between crystallites and chains segments in crystallites and were also seen at lower temperatures when replacing some water with tri-ethylene glycol (TEG). Material pockets increased resolution in processed samples. One broad T ɡ was observed in consolidated bars, at 335 or 350 K with or without TEG. In material pockets, these resolved into three transitions, similar to those observed before processing. Changes in relative magnitudes suggested some chain rearrangement leading to more bulk amorphous regions. Differences were detected between onset of drop in storage modulus and peaks in loss modulus and tan δ in pockets or bars, but generally led to the same conclusions. For bar samples, it was helpful to compare natural and log modulus scales. Good practice would use all these techniques in parallel to correctly identify relaxation temperatures.

text: Identifying transition temperatures in bloodmeal-based thermoplastics using material pocket DMTA Bloodmeal can be used to manufacture thermoplastics, but requires water, urea, sodium sulphite, and sodium dodecyl sulphate to modify chain mobility. Transition temperatures of bloodmeal, modified bloodmeal, and processed bloodmeal-based thermoplastics were compared using material pocket dynamic mechanical thermal analysis. The glass transition temperature (T ɡ) of bloodmeal dropped from 493 to 263 K using only water as a plasticizer but was restored when freeze dried. Modifying bloodmeal lowered T ɡ to 193 K. This was raised by drying, but not to that of unmodified bloodmeal indicating a permanent change. Three additional transitions were identified above T ɡ, for modified bloodmeal between 300 and 480 K. These were thought to be transitions of dehydrated bulk amorphous regions, amorphous regions between crystallites and chains segments in crystallites and were also seen at lower temperatures when replacing some water with tri-ethylene glycol (TEG). Material pockets increased resolution in processed samples. One broad T ɡ was observed in consolidated bars, at 335 or 350 K with or without TEG. In material pockets, these resolved into three transitions, similar to those observed before processing. Changes in relative magnitudes suggested some chain rearrangement leading to more bulk amorphous regions. Differences were detected between onset of drop in storage modulus and peaks in loss modulus and tan δ in pockets or bars, but generally led to the same conclusions. For bar samples, it was helpful to compare natural and log modulus scales. Good practice would use all these techniques in parallel to correctly identify relaxation temperatures.

year: 2012

title: Planning for the protection and enhancement of marine environments' wellbeing

authors: Barnsdall, Aaron

subjects: marine

abstract: The wellbeing of marine environments has a direct relationship with the types of whenua (land, placenta) use and management practices that go from the mountains to the sea. In Aotearoa, activities that are carried out in this land-marine interface, including those related to Nature-based Solutions (NbSs), are regulated by national, regional, and district policies (e.g., New Zealand Coastal Policy Statement, regional plans, and district plans). However, due to its novel character, not all current policies account for the realisation of NbSs nor are NbSs’ potential for addressing the wellbeing of our marine environments well understood.

This dissertation focuses on Tauranga Moana (the seas of Tauranga) as the chosen locality for the case study area, to:

i) investigate how the Ngapeke 7 Trust’s community participants in the Ngāti Pūkenga area of Tauranga Moana understand and value NbSs for addressing the wellbeing of their marine systems; and,
ii) review current planning policies and mechanisms to identify barriers, enablers, and gaps that support or hinder the implementation of NbSs in Tauranga Moana, observing through a Kaupapa Māori lens.

Findings emphasize that integrating mātauranga Māori and Māori Ecological Knowledge (MEK) with scientific knowledge offers a holistic approach to environmental management, enhancing decision-making, education, and policy. Key Māori values, including whakapapa, mauri, and kaitiakitanga, are central to this approach.

The research identifies gaps in policies regarding NbS realization and a need for greater understanding of NbS potential and Māori perspectives. Implications include the necessity of integrating MEK into environmental practices and policies, and the value of NbSs for effective and equitable environmental outcomes. Limitations include sample size and scope, which focused on the Ngapeke 7 block. This research contributes valuable insights for environmental planning and management by centring mātauranga Māori and values in NbS implementation for marine health.

text: Planning for the protection and enhancement of marine environments' wellbeing The wellbeing of marine environments has a direct relationship with the types of whenua (land, placenta) use and management practices that go from the mountains to the sea. In Aotearoa, activities that are carried out in this land-marine interface, including those related to Nature-based Solutions (NbSs), are regulated by national, regional, and district policies (e.g., New Zealand Coastal Policy Statement, regional plans, and district plans). However, due to its novel character, not all current policies account for the realisation of NbSs nor are NbSs’ potential for addressing the wellbeing of our marine environments well understood.

This dissertation focuses on Tauranga Moana (the seas of Tauranga) as the chosen locality for the case study area, to:

i) investigate how the Ngapeke 7 Trust’s community participants in the Ngāti Pūkenga area of Tauranga Moana understand and value NbSs for addressing the wellbeing of their marine systems; and,
ii) review current planning policies and mechanisms to identify barriers, enablers, and gaps that support or hinder the implementation of NbSs in Tauranga Moana, observing through a Kaupapa Māori lens.

Findings emphasize that integrating mātauranga Māori and Māori Ecological Knowledge (MEK) with scientific knowledge offers a holistic approach to environmental management, enhancing decision-making, education, and policy. Key Māori values, including whakapapa, mauri, and kaitiakitanga, are central to this approach.

The research identifies gaps in policies regarding NbS realization and a need for greater understanding of NbS potential and Māori perspectives. Implications include the necessity of integrating MEK into environmental practices and policies, and the value of NbSs for effective and equitable environmental outcomes. Limitations include sample size and scope, which focused on the Ngapeke 7 block. This research contributes valuable insights for environmental planning and management by centring mātauranga Māori and values in NbS implementation for marine health.

year: 2025-04-16