title: A structural isomer of the [CoFe3(CO)13]− anion

authors: Evans, Cameron

subjects: Cluster

abstract: The crystal structure of [Et4N][CoFe3 (CO) 13] has been determined, and shown to contain an anion with the CO ligands adopting a very different arrangement about the tetrahedral CoFe3 core to that found for the same anion, reported previously for the PPN+ salt. The relationship between the two structures can be understood in terms of Johnson's Ligand Polyhedral Model. In contrast the anion in [Et4N][CoRu3 (CO) 13] has the same geometry as that described in the corresponding PPN+ salt.

text: A structural isomer of the [CoFe3(CO)13]− anion The crystal structure of [Et4N][CoFe3 (CO) 13] has been determined, and shown to contain an anion with the CO ligands adopting a very different arrangement about the tetrahedral CoFe3 core to that found for the same anion, reported previously for the PPN+ salt. The relationship between the two structures can be understood in terms of Johnson's Ligand Polyhedral Model. In contrast the anion in [Et4N][CoRu3 (CO) 13] has the same geometry as that described in the corresponding PPN+ salt.

year: 2002-02-01

title: Instance-based learning: nearest neighbour with generalisation

authors: Martin, Brent

subjects: computer science

abstract: Instance-based learning is a machine learning method that classifies new examples by comparing them to those already seen and in memory. There are two types of instance-based learning; nearest neighbour and case-based reasoning. Of these two methods, nearest neighbour fell into disfavour during the 1980s, but regained popularity recently due to its simplicity and ease of implementation. Nearest neighbour learning is not without problems. It is difficult to define a distance function that works well for both discrete and continuous attributes. Noise and irrelevant attributes also pose problems. Finally, the specificity bias adopted by instance-based learning, while often an advantage, can over-represent small rules at the expense of more general concepts, leading to a marked decrease in classification performance for some domains. Generalised exemplars offer a solution. Examples that share the same class are grouped together, and so represent large rules more fully. This reduces the role of the distance function to determining the class when no rule covers the new example, which reduces the number of classification errors that result from inaccuracies of the distance function, and increases the influence of large rules while still representing small ones. This thesis investigates non-nested generalised exemplars as a way of improving the performance of nearest neighbour. The method is tested using benchmark domains and the results compared with documented results for ungeneralised exemplars, nested generalised exemplars, rule induction methods and a composite rule induction and nearest neighbour learner. The benefits of generalisation are isolated and the performance improvement measured. The results show that non-nested generalisation of exemplars improves the classification performance of nearest neighbour systems and reduces classification time.

text: Instance-based learning: nearest neighbour with generalisation Instance-based learning is a machine learning method that classifies new examples by comparing them to those already seen and in memory. There are two types of instance-based learning; nearest neighbour and case-based reasoning. Of these two methods, nearest neighbour fell into disfavour during the 1980s, but regained popularity recently due to its simplicity and ease of implementation. Nearest neighbour learning is not without problems. It is difficult to define a distance function that works well for both discrete and continuous attributes. Noise and irrelevant attributes also pose problems. Finally, the specificity bias adopted by instance-based learning, while often an advantage, can over-represent small rules at the expense of more general concepts, leading to a marked decrease in classification performance for some domains. Generalised exemplars offer a solution. Examples that share the same class are grouped together, and so represent large rules more fully. This reduces the role of the distance function to determining the class when no rule covers the new example, which reduces the number of classification errors that result from inaccuracies of the distance function, and increases the influence of large rules while still representing small ones. This thesis investigates non-nested generalised exemplars as a way of improving the performance of nearest neighbour. The method is tested using benchmark domains and the results compared with documented results for ungeneralised exemplars, nested generalised exemplars, rule induction methods and a composite rule induction and nearest neighbour learner. The benefits of generalisation are isolated and the performance improvement measured. The results show that non-nested generalisation of exemplars improves the classification performance of nearest neighbour systems and reduces classification time.

year: 1995-05

title: Tito Waiata-Tito Pūoro: extending the Kīngitanga music tradition.

authors: Rollo, Te Manaaroha Pirihira

subjects: Kīngitanga

abstract: Since 1858, music has always been an integral part of the Kīngitanga movement in New Zealand. As this music tradition evolves with the introduction of new musical idioms, genres and digital technology, so too do the practices of composing new works. 

The objective of this research was to construct a model for combining waiata, taonga pūoro and New Zealand electroacoustic music, in order to create new works that enhance the Kīngitanga music tradition.  Developing a model for composing and integrating these idioms within a Māori context presented problems, as traditional Māori music conflict with contemporary Western forms. 

To generate a framework and practical model for composing hybrid music, an examination of selected New Zealand works was first carried out through: a) the collection of 50 traditional and contemporary waiata relating to the Kīngitanga b) the collection of 10 New Zealand taonga pūoro works and c) a collection of 10 New Zealand electroacoustic music. An analysis of the music and compositional processes of each idiom implementing the ‘de-construct in order to re-construct’ approach to understand how they work musically and compositionally was accomplished. 

To demonstrate the outcome of my models, six original compositions were presented exploring different aspects of musical composition. These models focused on sound architecture and explored a) communicative relationships between composer, performer, and audience b) Holistic Co-hear-ence, implementing the horizontal and vertical layering model, and c) technical approaches using digital technology. To comply with Māori principles of composition and performance, each model and new work demonstrated Kaupapa Māori , Wairua  and Te Mana - Te Ihi - Te Wehi - Te Tapu . 

The findings and original contributions of this research provide a model that combines two musical traditions and three music idioms, and in turn, may guide contemporary composers in creating new works that extend the Kīngitanga music tradition.

text: Tito Waiata-Tito Pūoro: extending the Kīngitanga music tradition. Since 1858, music has always been an integral part of the Kīngitanga movement in New Zealand. As this music tradition evolves with the introduction of new musical idioms, genres and digital technology, so too do the practices of composing new works. 

The objective of this research was to construct a model for combining waiata, taonga pūoro and New Zealand electroacoustic music, in order to create new works that enhance the Kīngitanga music tradition.  Developing a model for composing and integrating these idioms within a Māori context presented problems, as traditional Māori music conflict with contemporary Western forms. 

To generate a framework and practical model for composing hybrid music, an examination of selected New Zealand works was first carried out through: a) the collection of 50 traditional and contemporary waiata relating to the Kīngitanga b) the collection of 10 New Zealand taonga pūoro works and c) a collection of 10 New Zealand electroacoustic music. An analysis of the music and compositional processes of each idiom implementing the ‘de-construct in order to re-construct’ approach to understand how they work musically and compositionally was accomplished. 

To demonstrate the outcome of my models, six original compositions were presented exploring different aspects of musical composition. These models focused on sound architecture and explored a) communicative relationships between composer, performer, and audience b) Holistic Co-hear-ence, implementing the horizontal and vertical layering model, and c) technical approaches using digital technology. To comply with Māori principles of composition and performance, each model and new work demonstrated Kaupapa Māori , Wairua  and Te Mana - Te Ihi - Te Wehi - Te Tapu . 

The findings and original contributions of this research provide a model that combines two musical traditions and three music idioms, and in turn, may guide contemporary composers in creating new works that extend the Kīngitanga music tradition.

year: 2014