title: Comparison of data and process refinement

authors: Reeves, Steve

subjects: computer science

abstract: When is it reasonable, or possible, to refine a one place buffer into a two place buffer? In order to answer this question we characterise refinement based on substitution in restricted contexts. We see that data refinement (specifically in Z) and process refinement give differing answers to the original question, and we compare the precise circumstances which give rise to this difference by translating programs and processes into labelled transition systems, so providing a common basis upon which to make the comparison. We also look at the closely related area of subtyping of objects. Along the way we see how all these sorts of computational construct are related as far as refinement is concerned, discover and characterise some (as far as we can tell) new sorts of refinement and, finally, point up some research avenues for the future.

text: Comparison of data and process refinement When is it reasonable, or possible, to refine a one place buffer into a two place buffer? In order to answer this question we characterise refinement based on substitution in restricted contexts. We see that data refinement (specifically in Z) and process refinement give differing answers to the original question, and we compare the precise circumstances which give rise to this difference by translating programs and processes into labelled transition systems, so providing a common basis upon which to make the comparison. We also look at the closely related area of subtyping of objects. Along the way we see how all these sorts of computational construct are related as far as refinement is concerned, discover and characterise some (as far as we can tell) new sorts of refinement and, finally, point up some research avenues for the future.

year: 2003-05

title: Towards large scale continuous EDA: a random matrix theory perspective

authors: Kabán, Ata

subjects: estimation of distribution algorithms

abstract: Estimation of distribution algorithms (EDA) are a major branch of evolutionary algorithms (EA) with some unique advantages in principle. They are able to take advantage of correlation structure to drive the search more efficiently, and they are able to provide insights about the structure of the search space. However, model building in high dimensions is extremely challenging and as a result existing EDAs lose their strengths in large scale problems.

Large scale continuous global optimisation is key to many real world problems of modern days. Scaling up EAs to large scale problems has become one of the biggest challenges of the field.

This paper pins down some fundamental roots of the problem and makes a start at developing a new and generic framework to yield effective EDA-type algorithms for large scale continuous global optimisation problems. Our concept is to introduce an ensemble of random projections of the set of fittest search points to low dimensions as a basis for developing a new and generic divide-and-conquer methodology. This is rooted in the theory of random projections developed in theoretical computer science, and will exploit recent advances of non-asymptotic random matrix theory.

text: Towards large scale continuous EDA: a random matrix theory perspective Estimation of distribution algorithms (EDA) are a major branch of evolutionary algorithms (EA) with some unique advantages in principle. They are able to take advantage of correlation structure to drive the search more efficiently, and they are able to provide insights about the structure of the search space. However, model building in high dimensions is extremely challenging and as a result existing EDAs lose their strengths in large scale problems.

Large scale continuous global optimisation is key to many real world problems of modern days. Scaling up EAs to large scale problems has become one of the biggest challenges of the field.

This paper pins down some fundamental roots of the problem and makes a start at developing a new and generic framework to yield effective EDA-type algorithms for large scale continuous global optimisation problems. Our concept is to introduce an ensemble of random projections of the set of fittest search points to low dimensions as a basis for developing a new and generic divide-and-conquer methodology. This is rooted in the theory of random projections developed in theoretical computer science, and will exploit recent advances of non-asymptotic random matrix theory.

year: 2013

title: Young people, technology and the future of te Reo Māori

authors: Keegan, Te Taka Adrian Gregory

abstract: After decades of neglect and, in some instances, suppression, te reo Māori has achieved a degree of recognition and support from the Government and people. Language strategies have been written, schooling is available in both languages, and since 1987 the language has had official status. However, despite demonstrable progress in some areas, it remains a small-minority language. Within New Zealand there are 157,000 speakers of te reo Māori, about 4.1 percent of the population (Statistics New Zealand: Te Tari Tatau, 2007), and the language is classified as 'vulnerable' by UNESCO (Mosley, 2010). The language continues to face considerable pressure from English, not just because English is a majority national language but because it is an increasingly global language, with a significant presence in culture, science, media and technology. This chapter considers the relationships between young people, technology and te reo Māori. It argues that technology is an important domain of use for te reo Māori, particularly the continued use of the language by young people.

text: Young people, technology and the future of te Reo Māori After decades of neglect and, in some instances, suppression, te reo Māori has achieved a degree of recognition and support from the Government and people. Language strategies have been written, schooling is available in both languages, and since 1987 the language has had official status. However, despite demonstrable progress in some areas, it remains a small-minority language. Within New Zealand there are 157,000 speakers of te reo Māori, about 4.1 percent of the population (Statistics New Zealand: Te Tari Tatau, 2007), and the language is classified as 'vulnerable' by UNESCO (Mosley, 2010). The language continues to face considerable pressure from English, not just because English is a majority national language but because it is an increasingly global language, with a significant presence in culture, science, media and technology. This chapter considers the relationships between young people, technology and te reo Māori. It argues that technology is an important domain of use for te reo Māori, particularly the continued use of the language by young people.

year: 2014