title: On dynamic feature weighting for feature drifting data streams

authors: Barddal, Jean Paul

subjects: computer science

abstract: The ubiquity of data streams has been encouraging the development of new incremental and adaptive learning algorithms. Data stream learners must be fast, memory-bounded, but mainly, tailored to adapt to possible changes in the data distribution, a phenomenon named concept drift. Recently, several works have shown the impact of a so far nearly neglected type of drifcccct: feature drifts. Feature drifts occur whenever a subset of features becomes, or ceases to be, relevant to the learning task. In this paper we (i) provide insights into how the relevance of features can be tracked as a stream progresses according to information theoretical Symmetrical Uncertainty; and (ii) how it can be used to boost two learning schemes: Naive Bayesian and k-Nearest Neighbor. Furthermore, we investigate the usage of these two new dynamically weighted learners as prediction models in the leaves of the Hoeffding Adaptive Tree classifier. Results show improvements in accuracy (an average of 10.69% for k-Nearest Neighbor, 6.23% for Naive Bayes and 4.42% for Hoeffding Adaptive Trees) in both synthetic and real-world datasets at the expense of a bounded increase in both memory consumption and processing time.

text: On dynamic feature weighting for feature drifting data streams The ubiquity of data streams has been encouraging the development of new incremental and adaptive learning algorithms. Data stream learners must be fast, memory-bounded, but mainly, tailored to adapt to possible changes in the data distribution, a phenomenon named concept drift. Recently, several works have shown the impact of a so far nearly neglected type of drifcccct: feature drifts. Feature drifts occur whenever a subset of features becomes, or ceases to be, relevant to the learning task. In this paper we (i) provide insights into how the relevance of features can be tracked as a stream progresses according to information theoretical Symmetrical Uncertainty; and (ii) how it can be used to boost two learning schemes: Naive Bayesian and k-Nearest Neighbor. Furthermore, we investigate the usage of these two new dynamically weighted learners as prediction models in the leaves of the Hoeffding Adaptive Tree classifier. Results show improvements in accuracy (an average of 10.69% for k-Nearest Neighbor, 6.23% for Naive Bayes and 4.42% for Hoeffding Adaptive Trees) in both synthetic and real-world datasets at the expense of a bounded increase in both memory consumption and processing time.

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: Will access to COVID-19 vaccine in Aotearoa be equitable for priority populations?

authors: Whitehead, Jesse

abstract: AIM: This research examines the equity implications of the geographic distribution of COVID-19 vaccine delivery locations in Aotearoa New Zealand under five potential scenarios: (1) stadium mega-clinics; (2) Community Based Assessment Centres; (3) GP clinics; (4) community pharmacies; and (5) schools.
METHOD: We mapped the distribution of Aotearoa New Zealand’s population and the location of potential vaccine delivery facilities under each scenario. Geostatistical techniques identified population clusters for Māori, Pacific peoples and people aged 65 years and over. We calculated travel times between all potential facilities and each Statistical Area 1 in the country. Descriptive statistics indicate the size and proportion of populations that could face significant travel barriers when accessing COVID-19 vaccinations.
RESULTS: Several areas with significant travel times to potential vaccine delivery sites were also communities identified as having an elevated risk of COVID-19 disease and severity. All potential scenarios for vaccine delivery, with the exception of schools, resulted in travel barriers for a substantial proportion of the population. Overall, these travel time barriers disproportionately burden Māori, older communities and people living in areas of high socioeconomic deprivation.
CONCLUSION: The equitable delivery of COVID-19 vaccines is key to an elimination strategy. However, if current health services and facilities are used without well-designed and supported outreach services, then access to vaccination is likely to be inequitable.

text: Will access to COVID-19 vaccine in Aotearoa be equitable for priority populations? AIM: This research examines the equity implications of the geographic distribution of COVID-19 vaccine delivery locations in Aotearoa New Zealand under five potential scenarios: (1) stadium mega-clinics; (2) Community Based Assessment Centres; (3) GP clinics; (4) community pharmacies; and (5) schools.
METHOD: We mapped the distribution of Aotearoa New Zealand’s population and the location of potential vaccine delivery facilities under each scenario. Geostatistical techniques identified population clusters for Māori, Pacific peoples and people aged 65 years and over. We calculated travel times between all potential facilities and each Statistical Area 1 in the country. Descriptive statistics indicate the size and proportion of populations that could face significant travel barriers when accessing COVID-19 vaccinations.
RESULTS: Several areas with significant travel times to potential vaccine delivery sites were also communities identified as having an elevated risk of COVID-19 disease and severity. All potential scenarios for vaccine delivery, with the exception of schools, resulted in travel barriers for a substantial proportion of the population. Overall, these travel time barriers disproportionately burden Māori, older communities and people living in areas of high socioeconomic deprivation.
CONCLUSION: The equitable delivery of COVID-19 vaccines is key to an elimination strategy. However, if current health services and facilities are used without well-designed and supported outreach services, then access to vaccination is likely to be inequitable.

year: 2021