title: Analytic solutions of the magnetic annihilation and reconnection problems. I. Planar flow profiles

authors: Watson, P.G.

subjects: mathematics

abstract: The phenomena of steady-state magnetic annihilation and reconnection in the vicinity of magnetic nulls are considered. It is shown that reconnective solutions can be derived by superposing the velocity and magnetic fields of simple magnetic annihilation models. These solutions contain most of the previous models for magnetic merging and reconnection, as well as introducing several new solutions. The various magnetic dissipation mechanisms are classified by examining the scaling of the Ohmic diffusion rate with plasma resistivity. Reconnection solutions generally allow more favorable "fast" dissipation scalings than annihilation models. In particular, reconnection models involving the advection of planar field components have the potential to satisfy the severe energy release requirements of the solar flare. The present paper is mainly concerned with magnetic fields embedded in strictly planar flows—a discussion of the more complicated three-dimensional flow patterns is presented in Part II [Phys. Plasmas 4, 110 (1997)].

text: Analytic solutions of the magnetic annihilation and reconnection problems. I. Planar flow profiles The phenomena of steady-state magnetic annihilation and reconnection in the vicinity of magnetic nulls are considered. It is shown that reconnective solutions can be derived by superposing the velocity and magnetic fields of simple magnetic annihilation models. These solutions contain most of the previous models for magnetic merging and reconnection, as well as introducing several new solutions. The various magnetic dissipation mechanisms are classified by examining the scaling of the Ohmic diffusion rate with plasma resistivity. Reconnection solutions generally allow more favorable "fast" dissipation scalings than annihilation models. In particular, reconnection models involving the advection of planar field components have the potential to satisfy the severe energy release requirements of the solar flare. The present paper is mainly concerned with magnetic fields embedded in strictly planar flows—a discussion of the more complicated three-dimensional flow patterns is presented in Part II [Phys. Plasmas 4, 110 (1997)].

year: 1997-01

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: Mouri matters Contextualizing mouri in Māori health discourse

authors: Penehira, Mera

abstract: The vision statement of Te Reo o Taranaki, “Tuku reo, tuku mouri: language, culture, crossing generations”, embodies the essence of an understanding of mouri which goes beyond the simple dictionary translations of “life force” or “life essence”. Indeed, there are numerous oral narratives—whakataukī (proverbs), waiata (songs), haka (dance), karanga (ceremonial call), whaikōrero (formal speech), karakia (prayers and incantations)—from the present day to our earliest records of Māori history that engage the notion of mouri. The purpose of this paper is to examine current understandings of mouri and, by linking the concept with linguistic, cultural and intergenerational terms—as in the Taranaki example—it will be argued that mouri is something of significance to our “being” and to our wellbeing.

text: Mouri matters Contextualizing mouri in Māori health discourse The vision statement of Te Reo o Taranaki, “Tuku reo, tuku mouri: language, culture, crossing generations”, embodies the essence of an understanding of mouri which goes beyond the simple dictionary translations of “life force” or “life essence”. Indeed, there are numerous oral narratives—whakataukī (proverbs), waiata (songs), haka (dance), karanga (ceremonial call), whaikōrero (formal speech), karakia (prayers and incantations)—from the present day to our earliest records of Māori history that engage the notion of mouri. The purpose of this paper is to examine current understandings of mouri and, by linking the concept with linguistic, cultural and intergenerational terms—as in the Taranaki example—it will be argued that mouri is something of significance to our “being” and to our wellbeing.

year: 2011