title: Efficient online evaluation of big data stream classifiers

authors: Bifet, Albert

subjects: Data Streams

abstract: The evaluation of classifiers in data streams is fundamental so that poorly-performing models can be identified, and either improved or replaced by better-performing models. This is an increasingly relevant and important task as stream data is generated from more sources, in real-time, in large quantities, and is now considered the largest source of big data. Both researchers and practitioners need to be able to effectively evaluate the performance of the methods they employ. However, there are major challenges for evaluation in a stream. Instances arriving in a data stream are usually time-dependent, and the underlying concept that they represent may evolve over time. Furthermore, the massive quantity of data also tends to exacerbate issues such as class imbalance. Current frameworks for evaluating streaming and online algorithms are able to give predictions in real-time, but as they use a prequential setting, they build only one model, and are thus not able to compute the statistical significance of results in real-time. In this paper we propose a new evaluation methodology for big data streams. This methodology addresses unbalanced data streams, data where change occurs on different time scales, and the question of how to split the data between training and testing, over multiple models.

text: Efficient online evaluation of big data stream classifiers The evaluation of classifiers in data streams is fundamental so that poorly-performing models can be identified, and either improved or replaced by better-performing models. This is an increasingly relevant and important task as stream data is generated from more sources, in real-time, in large quantities, and is now considered the largest source of big data. Both researchers and practitioners need to be able to effectively evaluate the performance of the methods they employ. However, there are major challenges for evaluation in a stream. Instances arriving in a data stream are usually time-dependent, and the underlying concept that they represent may evolve over time. Furthermore, the massive quantity of data also tends to exacerbate issues such as class imbalance. Current frameworks for evaluating streaming and online algorithms are able to give predictions in real-time, but as they use a prequential setting, they build only one model, and are thus not able to compute the statistical significance of results in real-time. In this paper we propose a new evaluation methodology for big data streams. This methodology addresses unbalanced data streams, data where change occurs on different time scales, and the question of how to split the data between training and testing, over multiple models.

year: 2015

title: Key points of value in B2B intermediated electronic networks

authors: Gibb, Jenny L.

abstract: The Internet is an electronic network with open standards that is associated with the exchange of information at heightened levels of reach, richness, transparency, and speed often directly between buyers and suppliers. The growing prominence of the Internet has led to the blurring of industry boundaries, as well as the emergence of new online intermediaries, and the disappearance of traditional ones. Happening simultaneously has been the development of new modes of business such as the B2B (IE) network. When combining the characteristics of these business models with the increased efficiencies and reduced information processing costs associated with the Internet, it becomes important to identify these new value creating opportunities. Though the advantages of the Internet and associated models have been widely espoused, to date there has been scant empirical investigation into these areas. Furthermore, as networked trade grows in popularity, whether entering into online or offline trade opportunities, an ongoing understanding is required of this mode of business. Hence, this thesis has examined the question "Where are the key sources of value in a B2B (IE) network?" 
Structuration theory, situated within the mid-range theorising perspective has been used in this thesis as an ontological lens due to its recognition of the duality of structure between man and machine, with the business intermediary and Internet respectively. This lens has served to facilitate an examination of these two brokering bodies in the development of processes, rules, regulations, and relationships that are embedded within this network structure. My analysis and theoretical development attempt to build a bridge between the existing strategy, networks, and B2B (IE) networks literatures through the use of the grounded theory development approach by moving between a skeletal empirical framework and the data from three case studies. The first case study, M-co is a network that operates in the highly volatile New Zealand electricity industry to provide a bid/offer price mechanism. The second case study is Ecomex, a network that is positioned within the more moderately volatile New Zealand timber industry. It offers a range of price mechanisms, of which the negotiated method appears to be the one most favoured by traders. The third case study is EDIS, a network embedded within a more stable environment, offering a service to general product traders using a fixed price method. 
The key theoretical contribution that this thesis makes is the development of a dynamic model that identifies the network as the primary unit of analysis, with three secondary units of analysis: the informational unit, the relational unit, and the central core unit, each with separate underlying dimensions. Though these secondary units are important as individual entities in their own right, what is more important is the understanding of how these units interact in order to realise the full value creation potential in a B2B (IE) network. This interaction process was found to be led by the business intermediary, positioned in the central core.

text: Key points of value in B2B intermediated electronic networks The Internet is an electronic network with open standards that is associated with the exchange of information at heightened levels of reach, richness, transparency, and speed often directly between buyers and suppliers. The growing prominence of the Internet has led to the blurring of industry boundaries, as well as the emergence of new online intermediaries, and the disappearance of traditional ones. Happening simultaneously has been the development of new modes of business such as the B2B (IE) network. When combining the characteristics of these business models with the increased efficiencies and reduced information processing costs associated with the Internet, it becomes important to identify these new value creating opportunities. Though the advantages of the Internet and associated models have been widely espoused, to date there has been scant empirical investigation into these areas. Furthermore, as networked trade grows in popularity, whether entering into online or offline trade opportunities, an ongoing understanding is required of this mode of business. Hence, this thesis has examined the question "Where are the key sources of value in a B2B (IE) network?" 
Structuration theory, situated within the mid-range theorising perspective has been used in this thesis as an ontological lens due to its recognition of the duality of structure between man and machine, with the business intermediary and Internet respectively. This lens has served to facilitate an examination of these two brokering bodies in the development of processes, rules, regulations, and relationships that are embedded within this network structure. My analysis and theoretical development attempt to build a bridge between the existing strategy, networks, and B2B (IE) networks literatures through the use of the grounded theory development approach by moving between a skeletal empirical framework and the data from three case studies. The first case study, M-co is a network that operates in the highly volatile New Zealand electricity industry to provide a bid/offer price mechanism. The second case study is Ecomex, a network that is positioned within the more moderately volatile New Zealand timber industry. It offers a range of price mechanisms, of which the negotiated method appears to be the one most favoured by traders. The third case study is EDIS, a network embedded within a more stable environment, offering a service to general product traders using a fixed price method. 
The key theoretical contribution that this thesis makes is the development of a dynamic model that identifies the network as the primary unit of analysis, with three secondary units of analysis: the informational unit, the relational unit, and the central core unit, each with separate underlying dimensions. Though these secondary units are important as individual entities in their own right, what is more important is the understanding of how these units interact in order to realise the full value creation potential in a B2B (IE) network. This interaction process was found to be led by the business intermediary, positioned in the central core.

year: 2004

title: Moko – A Research Project

authors: Te Awekotuku, Ngahuia

subjects: Maori

abstract: Moko colours the lives, and the skins, of all the people involved in the making of this book “Mau Moko”, which began as the Marsden project, “Ta Moko – Culture, Body Modification, and the Psychology of Identity”, 2001-2005. We proposed to study the origins, significance, technology and practice of Ta Moko from the pre-contact period to contemporary times, and to explore how this important art form has become a dynamic and positive assertion of being Maori in our changing world.

text: Moko – A Research Project Moko colours the lives, and the skins, of all the people involved in the making of this book “Mau Moko”, which began as the Marsden project, “Ta Moko – Culture, Body Modification, and the Psychology of Identity”, 2001-2005. We proposed to study the origins, significance, technology and practice of Ta Moko from the pre-contact period to contemporary times, and to explore how this important art form has become a dynamic and positive assertion of being Maori in our changing world.

year: 2008