title: Adaptive XGBoost for evolving data streams

authors: Montiel, Jacob

subjects: computer science

abstract: Boosting is an ensemble method that combines base models in a sequential manner to achieve high predictive accuracy. A popular learning algorithm based on this ensemble method is eXtreme Gradient Boosting (XGB). We present an adaptation of XGB for classification of evolving data streams. In this setting, new data arrives over time and the relationship between the class and the features may change in the process, thus exhibiting concept drift. The proposed method creates new members of the ensemble from mini-batches of data as new data becomes available. The maximum ensemble size is fixed, but learning does not stop when this size is reached because the ensemble is updated on new data to ensure consistency with the current concept. We also explore the use of concept drift detection to trigger a mechanism to update the ensemble. We test our method on real and synthetic data with concept drift and compare it against batch-incremental and instance-incremental classification methods for data streams.

text: Adaptive XGBoost for evolving data streams Boosting is an ensemble method that combines base models in a sequential manner to achieve high predictive accuracy. A popular learning algorithm based on this ensemble method is eXtreme Gradient Boosting (XGB). We present an adaptation of XGB for classification of evolving data streams. In this setting, new data arrives over time and the relationship between the class and the features may change in the process, thus exhibiting concept drift. The proposed method creates new members of the ensemble from mini-batches of data as new data becomes available. The maximum ensemble size is fixed, but learning does not stop when this size is reached because the ensemble is updated on new data to ensure consistency with the current concept. We also explore the use of concept drift detection to trigger a mechanism to update the ensemble. We test our method on real and synthetic data with concept drift and compare it against batch-incremental and instance-incremental classification methods for data streams.

year: 2020

title: Foucault, technologies of self, and the media: discourses of femininity in snowboarding culture

authors: Thorpe, Holly Aysha

subjects: foucault

abstract: This article draws on Foucault's concepts of discourse and technologies of self to analyze the relationship between young women and the media. More specifically, it sheds light on the various discursive constructions of femininity in the snowboarding media and examines the conditions under which female snowboarders learn to recognize and distinguish between different types of media discourses. It also examines the different ways in which women act on this knowledge, including the production of their own media forms. The article evaluates sexist discourses in the media and their effects on women's snowboarding experiences and considers women-only media forms as a foundation for wider social transformation. Ultimately, Foucault's unique conceptualization of power enables an account of the mundane and daily ways in which power is enacted and contested in snowboarding culture and allows an analysis that focuses on the female snowboarder as both an object and a subject of media power relations.

text: Foucault, technologies of self, and the media: discourses of femininity in snowboarding culture This article draws on Foucault's concepts of discourse and technologies of self to analyze the relationship between young women and the media. More specifically, it sheds light on the various discursive constructions of femininity in the snowboarding media and examines the conditions under which female snowboarders learn to recognize and distinguish between different types of media discourses. It also examines the different ways in which women act on this knowledge, including the production of their own media forms. The article evaluates sexist discourses in the media and their effects on women's snowboarding experiences and considers women-only media forms as a foundation for wider social transformation. Ultimately, Foucault's unique conceptualization of power enables an account of the mundane and daily ways in which power is enacted and contested in snowboarding culture and allows an analysis that focuses on the female snowboarder as both an object and a subject of media power relations.

year: 2008

title: “On and On It Goes”: Representations of the New Zealand Wars in novels, film, and theatre

authors: Sheridan, Brendan Daniel

subjects: History

abstract: This thesis considers fictional representations of the New Zealand Wars. Through the media of novels, feature films, and drama with links to Shakespeare, it explores common features between representations. It examines how these representations change in tone or style over time and how different representations negotiate the complex issues of race, gender, and colonialism.
	I examine key representations ranging from 1861 to 2017 in terms of genre. I begin with the nineteenth-century novel as many of the key tropes used in representations of the New Zealand Wars emerge in this period. I then look at the twentieth-century novel, before concentrating specifically on Maurice Shadbolt and Witi Ihimaera. My discussion then turns to the genres of film and theatre. In all of these diverse representations there are recurring tropes and motifs. Many of the fictions feature stock characters such as the European traveller, the imperial official, and the Māori maiden and bear the imprint of historical romance conventions, popularised by Sir Walter Scott’s Waverly and James Fenimore Cooper’s The Last of the Mohicans. The vast majority of stories take place in the North Island between 1860 and 1870. Variations in the depiction of historical events are shaped by the historical scholarship and dominant ideologies of the time, such as the post-colonial tonal shift that emerges following the publication of work by James Belich and Ranginui Walker. I contextualise representations with their point in history, and how they treat the New Zealand Wars in terms of events, characters, and historical figures. 
	Through this approach, my thesis argues that representations of the New Zealand Wars do not form themselves in isolation and do not occur in isolated clusters. This thesis seeks to demonstrate that representations of the New Zealand Wars occur on a steady continuum. Representations of the conflict exist in parallel to one another (intentional or not) and are affected by the social climate, dominant ideologies, and published histories available to the author at the time of writing. The variety of representations—novel, feature film, stage play—share many core tropes. Even so, chronologically this continuum also features shifts in tone, ideologies, and sympathies. A novel of the 1980s has a very different perspective regarding settlers compared to a novel from the 1860s. In the same manner, a play staged in the 2000s shows a different attitude towards the conflict compared to a film from the 1940s. This thesis demonstrates that while representations of the New Zealand Wars share a common subject, how they approach the material is constantly evolving.

text: “On and On It Goes”: Representations of the New Zealand Wars in novels, film, and theatre This thesis considers fictional representations of the New Zealand Wars. Through the media of novels, feature films, and drama with links to Shakespeare, it explores common features between representations. It examines how these representations change in tone or style over time and how different representations negotiate the complex issues of race, gender, and colonialism.
	I examine key representations ranging from 1861 to 2017 in terms of genre. I begin with the nineteenth-century novel as many of the key tropes used in representations of the New Zealand Wars emerge in this period. I then look at the twentieth-century novel, before concentrating specifically on Maurice Shadbolt and Witi Ihimaera. My discussion then turns to the genres of film and theatre. In all of these diverse representations there are recurring tropes and motifs. Many of the fictions feature stock characters such as the European traveller, the imperial official, and the Māori maiden and bear the imprint of historical romance conventions, popularised by Sir Walter Scott’s Waverly and James Fenimore Cooper’s The Last of the Mohicans. The vast majority of stories take place in the North Island between 1860 and 1870. Variations in the depiction of historical events are shaped by the historical scholarship and dominant ideologies of the time, such as the post-colonial tonal shift that emerges following the publication of work by James Belich and Ranginui Walker. I contextualise representations with their point in history, and how they treat the New Zealand Wars in terms of events, characters, and historical figures. 
	Through this approach, my thesis argues that representations of the New Zealand Wars do not form themselves in isolation and do not occur in isolated clusters. This thesis seeks to demonstrate that representations of the New Zealand Wars occur on a steady continuum. Representations of the conflict exist in parallel to one another (intentional or not) and are affected by the social climate, dominant ideologies, and published histories available to the author at the time of writing. The variety of representations—novel, feature film, stage play—share many core tropes. Even so, chronologically this continuum also features shifts in tone, ideologies, and sympathies. A novel of the 1980s has a very different perspective regarding settlers compared to a novel from the 1860s. In the same manner, a play staged in the 2000s shows a different attitude towards the conflict compared to a film from the 1940s. This thesis demonstrates that while representations of the New Zealand Wars share a common subject, how they approach the material is constantly evolving.

year: 2019