title: Revisiting deep hybrid models for out-of-distribution detection

authors: Schlumbom, Paul-Ruben

subjects: computer science

abstract: Deep hybrid models (DHMs) for out-of-distribution (OOD) detection, jointly training a deep feature extractor with a classification head and a density estimation head based on a normalising flow, provide a conceptually appealing approach to visual OOD detection. The paper that introduced this approach reported 100% AuROC in experiments on two standard benchmarks, including one based on the CIFAR-10 data. As there are no implementations available, we set out to reproduce the approach by carefully filling in gaps in the description of the algorithm. Although we were unable to attain 100% OOD detection rates, and our results indicate that such performance is impossible on the CIFAR-10 benchmark, we achieved good OOD performance. We provide a detailed analysis of when the architecture fails and argue that it introduces an adversarial relationship between the classification component and the density estimator, rendering it highly sensitive to the balance of these two components and yielding a collapsed feature space without careful fine-tuning. Our implementation of DHMs is publicly available.

text: Revisiting deep hybrid models for out-of-distribution detection Deep hybrid models (DHMs) for out-of-distribution (OOD) detection, jointly training a deep feature extractor with a classification head and a density estimation head based on a normalising flow, provide a conceptually appealing approach to visual OOD detection. The paper that introduced this approach reported 100% AuROC in experiments on two standard benchmarks, including one based on the CIFAR-10 data. As there are no implementations available, we set out to reproduce the approach by carefully filling in gaps in the description of the algorithm. Although we were unable to attain 100% OOD detection rates, and our results indicate that such performance is impossible on the CIFAR-10 benchmark, we achieved good OOD performance. We provide a detailed analysis of when the architecture fails and argue that it introduces an adversarial relationship between the classification component and the density estimator, rendering it highly sensitive to the balance of these two components and yielding a collapsed feature space without careful fine-tuning. Our implementation of DHMs is publicly available.

year: 2025

title: Superintegrability and associated polynomial solutions: Euclidean space and the sphere in two dimensions

authors: Kalnins, Ernie G.

subjects: Mathematics

abstract: In this work we examine the basis functions for those classical and quantum mechanical systems in two dimensions which admit separation of variables in at least two coordinate systems. We do this for the corresponding systems defined in Euclidean space and on the two-dimensional sphere. We present all of these cases from a unified point of view. In particular, all of the special functions that arise via variable separation have their essential features expressed in terms of their zeros. The principal new results are the details of the polynomial bases for each of the nonsubgroup bases, not just the subgroup Cartesian and polar coordinate cases, and the details of the structure of the quadratic algebras. We also study the polynomial eigenfunctions in elliptic coordinates of the n-dimensional isotropic quantum oscillator.

text: Superintegrability and associated polynomial solutions: Euclidean space and the sphere in two dimensions In this work we examine the basis functions for those classical and quantum mechanical systems in two dimensions which admit separation of variables in at least two coordinate systems. We do this for the corresponding systems defined in Euclidean space and on the two-dimensional sphere. We present all of these cases from a unified point of view. In particular, all of the special functions that arise via variable separation have their essential features expressed in terms of their zeros. The principal new results are the details of the polynomial bases for each of the nonsubgroup bases, not just the subgroup Cartesian and polar coordinate cases, and the details of the structure of the quadratic algebras. We also study the polynomial eigenfunctions in elliptic coordinates of the n-dimensional isotropic quantum oscillator.

year: 1996-12

title: Replacing medical and social models of disability by a communities-based model of equal access for people of differing abilities: A Māori perspective

authors: Hickey, Huhana

subjects: New Zealand

abstract: I argue here that although the social model of disability which currently prevails in New Zealand is preferable in many ways to the earlier medical model, it is nevertheless based on a largely uni-dimensional concept of society and continues an established tradition of negativity, one that is evident in the ongoing use of the word 'disabled' itself by those who subscribe to the social model. I argue here that the social model of disability should be replaced by a communities-based model of equal access for people of differing abilities, one that is, in the New Zealand context, informed by a further developed Māori model of health and wellbeing proposed by Mason Durie, Te Whare Tapa Whā. This mode is designed in such a way as to accommodate difference and diversity. In the discussion of different models, I use the words 'disabled' and 'disability'; in other contexts, I replace 'disabled people' by 'people of differing abilities'.

text: Replacing medical and social models of disability by a communities-based model of equal access for people of differing abilities: A Māori perspective I argue here that although the social model of disability which currently prevails in New Zealand is preferable in many ways to the earlier medical model, it is nevertheless based on a largely uni-dimensional concept of society and continues an established tradition of negativity, one that is evident in the ongoing use of the word 'disabled' itself by those who subscribe to the social model. I argue here that the social model of disability should be replaced by a communities-based model of equal access for people of differing abilities, one that is, in the New Zealand context, informed by a further developed Māori model of health and wellbeing proposed by Mason Durie, Te Whare Tapa Whā. This mode is designed in such a way as to accommodate difference and diversity. In the discussion of different models, I use the words 'disabled' and 'disability'; in other contexts, I replace 'disabled people' by 'people of differing abilities'.

year: 2006-02