A comparison of recent nonparametric methods for testing effects in two-by-two factorial designs

The two-way two-levels crossed factorial design is a commonly used design by practitioners at the exploratory phase of industrial experiments. The F-test in the usual linear model for analysis of variance (ANOVA) is a key instrument to assess the impact of each factor and of their interactions on the response variable. However, if assumptions such as normal distribution and homoscedasticity of errors are violated, the conventional wisdom is to resort to nonparametric tests. Nonparametric methods, rank-based as well as permutation, have been a subject of recent investigations to make them effective in testing the hypotheses of interest and to improve their performance in small sample situations. In this study, we assess the performances of some nonparametric methods and, more importantly, we compare their powers. Specifically, we examine three permutation methods (Constrained Synchronized Permutations, Unconstrained Synchronized Permutations and Wald-Type Permutation Test), a rank-based method (Aligned Rank Transform) and a parametric method (ANOVA-Type Test). In the simulations, we generate datasets with different configurations of distribution of errors, variance, factor's effect and number of replicates. The objective is to elicit practical advice and guides to practitioners regarding the sensitivity of the tests in the various configurations, the conditions under which some tests cannot be used, the tradeoff between power and type I error, and the bias of the power on one main factor analysis due to the presence of effect of the other factor. A dataset from an industrial engineering experiment for thermoformed packaging production is used to illustrate the application of the various methods of analysis, taking into account the power of the test suggested by the objective of the experiment.     

Stress-strength reliability of exponentiated Fréchet distributions based on Type-II censored data

In this paper, we consider inference of the stress-strength parameter, R, based on two independent Type-II censored samples from exponentiated Fréchet populations with different index parameters. The maximum likelihood and uniformly minimum variance unbiased estimators, exact and asymptotic confidence intervals and hypotheses testing for R are obtained. We conduct a Monte Carlo simulation study to evaluate the performance of these estimators and confidence intervals. Finally, two real data sets are analysed for illustrative purposes.     

Prediction of future failures times based on Type-I hybrid censored samples of random sample sizes

In this article, we consider the prediction of future failure times based on Type-I hybrid censored samples. Point predictors and prediction intervals using different procedures are discussed for a general model. The exponential and Rayleigh distributions are used as illustrative examples to show the most simplified forms of the so obtained predictors as well as prediction intervals. Intensive simulation study and a real life dataset are presented to illustrate our findings and results.     

Between butch/femme: On the performance of race,gender, and sexuality in a YouTube web series

Drawing on a legacy of Black television and film production, Black web series remediate earlier media forms in order to usher in a twenty-first-century revival of indie Black cultural production. Specifically, video sharing and social media platforms operate as a sphere in which content creators and users are afforded unique opportunities to engage with video content and each other on a variety of levels. Focusing on the YouTube media sphere, one can also observe the myriad ways in which the performance of race, gender, and sexuality influences the types of discourse that circulate within these sites. In watching and analyzing Black queer web series on YouTube, I examine how the performance of gender and sexuality by Black queer women within and outside of web series are policed and protected by both community insiders and outsiders. Utilizing an ethnographic framework, which includes a critical discourse analysis of the YouTube comments for the series Between Women, as well as a textual analysis of series content, this project draws conclusions about the role that the politics of pleasure, performance, and the public sphere play in the recognition and/or refusal of queer sexuality within Black communities.     

Inequality in digital skills and the adoption of online safety behaviors

ABSTRACT

Cyber-safety behaviors are important in preventing the loss of an individual's digital assets and ensuring the safety of important daily online activities. Individuals’ cyber-safety is also critical for national cybersecurity. The issue is highly relevant for Israel, a country that relies on the digital capabilities of its workers for its major technology industries and is also often a target of cyberwarfare and cybercrime attacks. The purpose of this study is to identify the determinants of cyber-safety behavior. We investigate the role of age, gender and education in the use of safety-related digital skills and antivirus software. Using a 2014 survey of a national sample of Internet users in Israel (N?=?1850), we found that age, gender, education and quality of access are associated with the level of users’ digital security skills. In addition, these skills and the frequency of conducting financial activities online are the main determinants of antivirus behaviors. Our results expand the understanding of cyber-safety by showing that social and digital disparities are reproduced in the use of measures to prevent online threats, putting the digitally disadvantaged at greater risk of becoming victims of online threats.     

#IAmNotAfraidToSayIt: stories of sexual violence as everyday political speech on Facebook

ABSTRACT

The debate about the power and influence of networked publics often focuses on large-scale political events, activist campaigns and protest activity – the more visible forms of political engagement. On the other hand, digitally mediated activism is often questioned and sometimes derided as a lesser form of dissent, as it is easier to engage in, highly affective, and offers few assurances of sustainability of the change it calls for. But what about everyday political speech online, where social media platforms can contribute to a personalisation of politics? Can social media users express their views online and make a difference? This paper analyses around 3500 Facebook posts stemming from the #ЯНеБоюсьСказати (Ukrainian for #IAmNotAfraidToSayIt) online campaign that was started in the Ukrainian segment of Facebook in July 2016 by a local activist to raise awareness of how widespread sexual violence and sexual harassment are in the Ukrainian society. The paper argues that networked conversations about everyday rights and affective stories about shared experiences of injustice, underpinned by the affordances of social media platforms for sharing and discussing information and participating in everyday politics, can emerge as viable forms of networked feminist activism and can have real impact on the discursive status quo of an issue, both in the digital sphere and beyond it.     

Techno-Wizardry and movie magic: the trace of labour (or lack thereof) in 3D digital animation

ABSTRACT

This paper will argue that 3D digital animation, unlike its 2D and stop-motion counterparts, currently lacks recognisable self-reflexive aesthetic devices through which the trace of animators’ labour can be made visible. It will open with a brief history of how animation has previously shown its workings; from the pencil-wielding hand of Émile Cohl to the opening seconds of South Park, plus the intentional and unintentional smears and multiples visible on animation cells. These devices will then be discussed in relation to Marx’s analysis of the commodity in Capital Vol. 1, and how the process of fetishisation is momentarily disrupted by imperfections in the object which have been caused by production errors. These faults reconnect the object to its producer through the trace of (imperfect) labour which remains visible on the surface. In animation, similar (albeit consciously made) ‘errors’ connect the perceptive viewer directly to the work of 2D or stop-motion animators. This paper will argue the need for an equivalent to emerge in 3D digital animation, as well as highlighting some contemporary animators testing and subverting the limits of 3D and sketching some possible ways these might encourage further formal innovations.     

Information society and digital divide in South Africa: results of longitudinal surveys

Integration into the information society implies that information plays an increasingly important role in all sectors of society and holds distinct social and economic benefits. Discourses on the information society are, however, also associated with the digital divide and inequalities in access to and use of information and communication technologies (ICTs). Within sub-Saharan Africa, South Africa is often regarded as one of the most information-integrated societies due to widespread mobile phone ownership, among other things. However, while ICT access has been emphasized, research also points to the role of demographic, socio-economic and cultural factors such as ethnicity, income, education and gender. This article discusses the results of questionnaire surveys conducted by Afrobarometer among probability South African samples in 2008 and 2011. The results indicate that individual Internet use and mobile Internet access were lower than estimated in the literature. Furthermore, gender gaps, as well as considerable gaps between population groups and educational levels, were found in Internet and computer use, mobile ownership and access to mobile Internet and accessing news via the Internet. Conclusions regarding strategies for bridging the digital divide and integrating South Africa into the information society are discussed.     

Curating the Soul: Foucault's concept of hupomnemata and the digital technology of self-care

This paper explores how online actions such as the practice of digital self-writing shape our offline identity. We start with an examination of the concept of hupomnemata – a practice of self-writing in which notes are kept as a ‘material record of things read, heard, or thought’ in the intent of shaping the self [Foucault (1997). Self writing. In P. Rabinow (Ed.), Ethics, subjectivity and truth. The essential works of Foucault, 1954–1984. Volume 1 (pp. 207–222). New York, NY: The New Press p. 209] – before arguing that the practice of digital content curation can be understood as a modern-day variant of the Greco-Roman hupomnemata. Although the work of the digital curator is conducted online, this paper positions contemporary curatorial practices as acts of self-exploration, self-cultivation, and self-care, which nourish offline identity and which ultimately work to shape the offline, corporeal self.