title: How effective is Cauchy-EDA in high dimensions?

authors: Sanyang, Momodou L.

subjects: Machine learning

abstract: We consider the problem of high dimensional blackbox optimisation via Estimation of Distribution Algorithms (EDA) and the use of heavy-tailed search distributions in this setting. Some authors have suggested that employing a heavy tailed search distribution, such as a Cauchy, may make EDA better explore a high dimensional search space. However, other authors have found Cauchy search distributions are less effective than Gaussian search distributions in high dimensional problems. In this paper, we set out to resolve this controversy. To achieve this we run extensive experiments on a battery of high-dimensional test functions, and develop some theory which shows that small search steps are always more likely to move the search distribution towards the global optimum than large ones and, in particular, large search steps in high-dimensional spaces nearly always do badly in this respect. We hypothesise that, since exploration by large steps is mostly counterproductive in high dimensions, and since the fraction of good directions decays exponentially fast with increasing dimension, instead one should focus mainly on finding the right direction in which to move the search distribution. We propose a minor change to standard Gaussian EDA which implicitly achieves this aim, and our experiments on a sequence of test functions confirm the good performance of our new approach.

text: How effective is Cauchy-EDA in high dimensions? We consider the problem of high dimensional blackbox optimisation via Estimation of Distribution Algorithms (EDA) and the use of heavy-tailed search distributions in this setting. Some authors have suggested that employing a heavy tailed search distribution, such as a Cauchy, may make EDA better explore a high dimensional search space. However, other authors have found Cauchy search distributions are less effective than Gaussian search distributions in high dimensional problems. In this paper, we set out to resolve this controversy. To achieve this we run extensive experiments on a battery of high-dimensional test functions, and develop some theory which shows that small search steps are always more likely to move the search distribution towards the global optimum than large ones and, in particular, large search steps in high-dimensional spaces nearly always do badly in this respect. We hypothesise that, since exploration by large steps is mostly counterproductive in high dimensions, and since the fraction of good directions decays exponentially fast with increasing dimension, instead one should focus mainly on finding the right direction in which to move the search distribution. We propose a minor change to standard Gaussian EDA which implicitly achieves this aim, and our experiments on a sequence of test functions confirm the good performance of our new approach.

year: 2016

title: Sex and gender in World of Warcraft: Identities, love, and power

authors: Todd, Cherie Jane

subjects: gender

abstract: This thesis examines how gamers construct sex and gender in the online game World of Warcraft (WoW), with a particular focus on connections between intimate relationships and gendered power relations. Every year more people choose to play online games but despite this ‘gaming culture’ continues to be dominated by masculinist discourse that works to marginalise those who do not conform to patriarchal and heteronormative ways of being. This in turn impacts upon the ways in which gamers ‘perform’ or ‘do’ their identities including interacting and communicating with others. This research utilises feminist poststructuralist theories to examine: how gamers construct and perform their sexed and gendered identities in WoW; the intimate and loving relationships gamers establish and maintain in WoW and beyond; and, the ways in which gendered power relations are constructed in WoW’s online gaming culture and how this affects gamers relationships both online and offline. Butler’s theory regarding performativity is also utilised to aid in the analysis of gendered and sexual identities within WoW.

The theoretical lens informs the choice of methods. Interviews, online questionnaires, follow-up email questionnaires, discussions within online game forum websites, and autoethnography were used to examine 57 participants’ (35 men and 22 women) experiences of WoW’s ‘gaming culture’ and their relationships with other players. The findings are organised across three substantive chapters. The first focuses on the body and how gender and sexuality are represented via avatars in WoW. It also highlights how people who do not conform to heteronormative ideals and values are marginalised. The second substantive chapter discusses participants’ experiences of intimate and loving relationships in WoW, including how obstacles such as geographical distance are negotiated in relationships between gamers. In addition, I highlight how gaming can be understood as a sensory experience, where emotion and affect are important elements in contemporary game design, and how these elements are evident in WoW and the relationships that evolve within that space. The third and final substantive chapter examines the culture of online games, including the ways in which sexism and misogyny are evident within WoW and the wider gaming community. In particular, I look at how women are positioned in games, as players, game designers, and game critics. 

Considering the growing practice of gaming as an ‘everyday’ social activity – as well as the depth and intensity of friendships and intimate relationships between gamers – encourages a more critical understanding of the normative and powerful ways in which bodies and online spaces are mutually constituted. WoW as a digital world has distinctive spatial aspects. This study adopts a feminist geographical approach in order to contribute to critical discussions on the relationship between gender and sexual subjectivities, intimate relationships in WoW, and the culture of gaming.

text: Sex and gender in World of Warcraft: Identities, love, and power This thesis examines how gamers construct sex and gender in the online game World of Warcraft (WoW), with a particular focus on connections between intimate relationships and gendered power relations. Every year more people choose to play online games but despite this ‘gaming culture’ continues to be dominated by masculinist discourse that works to marginalise those who do not conform to patriarchal and heteronormative ways of being. This in turn impacts upon the ways in which gamers ‘perform’ or ‘do’ their identities including interacting and communicating with others. This research utilises feminist poststructuralist theories to examine: how gamers construct and perform their sexed and gendered identities in WoW; the intimate and loving relationships gamers establish and maintain in WoW and beyond; and, the ways in which gendered power relations are constructed in WoW’s online gaming culture and how this affects gamers relationships both online and offline. Butler’s theory regarding performativity is also utilised to aid in the analysis of gendered and sexual identities within WoW.

The theoretical lens informs the choice of methods. Interviews, online questionnaires, follow-up email questionnaires, discussions within online game forum websites, and autoethnography were used to examine 57 participants’ (35 men and 22 women) experiences of WoW’s ‘gaming culture’ and their relationships with other players. The findings are organised across three substantive chapters. The first focuses on the body and how gender and sexuality are represented via avatars in WoW. It also highlights how people who do not conform to heteronormative ideals and values are marginalised. The second substantive chapter discusses participants’ experiences of intimate and loving relationships in WoW, including how obstacles such as geographical distance are negotiated in relationships between gamers. In addition, I highlight how gaming can be understood as a sensory experience, where emotion and affect are important elements in contemporary game design, and how these elements are evident in WoW and the relationships that evolve within that space. The third and final substantive chapter examines the culture of online games, including the ways in which sexism and misogyny are evident within WoW and the wider gaming community. In particular, I look at how women are positioned in games, as players, game designers, and game critics. 

Considering the growing practice of gaming as an ‘everyday’ social activity – as well as the depth and intensity of friendships and intimate relationships between gamers – encourages a more critical understanding of the normative and powerful ways in which bodies and online spaces are mutually constituted. WoW as a digital world has distinctive spatial aspects. This study adopts a feminist geographical approach in order to contribute to critical discussions on the relationship between gender and sexual subjectivities, intimate relationships in WoW, and the culture of gaming.

year: 2015

title: 'The voices caused him to become porangi': Maori Patients in the Auckland Lunatic Asylum, 1860-1900

authors: Burke, Lorelle J.

abstract: Histories of the asylum have raised a number of important questions about the way 'race' intersects along colonial, medical and legal boundaries. The experience of Maori patients at the Auckland Lunatic Asylum was a site where colonial attitudes towards 'race' were played out along such lines. By employing 'race' as a category of historical analysis, one can attempt to investigate how the asylum processes in Aotearoa/New Zealand exemplified the question of 'race' in an effort to make more visible the experiences, attitudes and responses of Maori asylum patients. 
This thesis examines colonial 'madness' by investigating the experiences of Maori patients at the Auckland Lunatic Asylum from 1860-1900. Using patient case records from this period this thesis interrogates the experiences of Maori patients in a colonial asylum, away from their whanau, communities, and tribal networks; what factors contributed to this, and how colonial attitudes towards these patients were acted out. The first chapter therefore, explores the 'medico-legal' management of these Maori patients, followed in Chapter Two by a broad overview of the Maori patients themselves. Chapter Three analyses the case records in more depth illustrating the complex interplay between 'race', gender, 'whiteness' and culture. Chapter Four looks at the way Maori dealt with the insane away from European institutions such as the asylum, emphasising how colonial histories of medicine now paying attention to Indigenous peoples in their context, and to medical pluralism, which reflects European models on one hand and on the other, Maori modes. 
In considering Maori patients, this thesis reflects on the very 'human experience' that can be revealed by using asylum case files, and what such sources may suggest about 'race' as an implicit part of colonial asylum administration. More widely, the paper also reflects on colonisation, Maori and the asylum, and the ways in which Maori used the asylum.

text: 'The voices caused him to become porangi': Maori Patients in the Auckland Lunatic Asylum, 1860-1900 Histories of the asylum have raised a number of important questions about the way 'race' intersects along colonial, medical and legal boundaries. The experience of Maori patients at the Auckland Lunatic Asylum was a site where colonial attitudes towards 'race' were played out along such lines. By employing 'race' as a category of historical analysis, one can attempt to investigate how the asylum processes in Aotearoa/New Zealand exemplified the question of 'race' in an effort to make more visible the experiences, attitudes and responses of Maori asylum patients. 
This thesis examines colonial 'madness' by investigating the experiences of Maori patients at the Auckland Lunatic Asylum from 1860-1900. Using patient case records from this period this thesis interrogates the experiences of Maori patients in a colonial asylum, away from their whanau, communities, and tribal networks; what factors contributed to this, and how colonial attitudes towards these patients were acted out. The first chapter therefore, explores the 'medico-legal' management of these Maori patients, followed in Chapter Two by a broad overview of the Maori patients themselves. Chapter Three analyses the case records in more depth illustrating the complex interplay between 'race', gender, 'whiteness' and culture. Chapter Four looks at the way Maori dealt with the insane away from European institutions such as the asylum, emphasising how colonial histories of medicine now paying attention to Indigenous peoples in their context, and to medical pluralism, which reflects European models on one hand and on the other, Maori modes. 
In considering Maori patients, this thesis reflects on the very 'human experience' that can be revealed by using asylum case files, and what such sources may suggest about 'race' as an implicit part of colonial asylum administration. More widely, the paper also reflects on colonisation, Maori and the asylum, and the ways in which Maori used the asylum.

year: 2006