Analysis of Variance by Randomization when Variances are Unequal

If there are significant factor and interaction effects with analysis of variance using ran-domization inference, they can be detected by tests that compare the F -statistics for the real data with the distributions of these statistics obtained by randomly allocating either the original observations or the residuals to the various factor combinations. Such tests involve the assumption that the effect of factors or interactions is to shift the observations for a factor combination by a fixed amount, without changing the amount of variation at that combination. In reality the expected amount of variation at each factor combination, as measured by the variance, may not be constant, which may upset the properties of the tests for the effects of factors and interactions. This paper discusses several possible methods for adjusting the randomization procedure to allow for this type of problem, including generalizations of methods that have been proposed for comparing the means of several samples when there is unequal variance but no factor structure. A simulation study shows that the best of the methods examined is one for which the randomized sets of data are designed to approximate the distributions of F -statistics when unequal variance is present.     

Temporary Work and Insecurity in Britain: A Problem Solved?

Temporary workers in Britain experience lower job quality. However, the proportion of employees on temporary contracts has fallen since a decade ago to just 5.5% in 2005. There have also been qualitative improvements. Many temporary workers now fall under the protection of the Fixed Term Employees’ (Prevention of Less Favourable Treatment) Regulations 2002, and the relative pay of fixed-term contract workers has since improved. In contrast, the subsequent fortunes of seasonal and casual workers with short contracts have been mixed. Furthermore, the Act excludes agency workers, and the paper calls for additional legislative action to ensure fair treatment for this group.

Quality Controlled: An Ethnographic Account of Tea Party Messaging and Action

What strategies do Tea Party movement organizers use to achieve frame alignment, that is, uniformity of grievance, purpose, and action, with their participants? Evidence to answer this question is gathered from a year‐length participant‐observation case study of one city‐based Tea Party organization, primarily through the meetings of its localized grassroots chapters. Principal findings are that Tea Party organizers employ quality control of off‐message grievances, for example, abortion, as well as any action or communication that would or could be perceived as racially prejudicial, or otherwise inflammatory. Formally, these findings demonstrate the influence of organizational hierarchy on grassroots practice. Substantively, they demonstrate the complex relationship between a broader conservative ideological repertoire as empirically deployed by participants, and the more focused frame alignment attempts of a particular social movement organization. In short, the findings elucidate the importance of interaction and organizational structure as they influence social movement messaging and action.     

Social media use and democratic engagement: a comparative study of Hong Kong,Taiwan, and China

Recent studies in political communication have found a generally positive role of social media in democratic engagement. However, most research on youth’s social media use in relation to their political engagement has been conducted in the context of American and European democracies. This study fills a gap in the literature by examining the effects of the uses and structural features of social media on democratic engagement in three different Asian political systems: Taiwan (young liberal democracy); Hong Kong (partial democracy); and China (one-party state). The findings showed that sharing political information and connections with public actors consistently predicted offline participation (i.e., civic and political participation) and online participation (i.e., online political expression and online activism) in the three political systems. Although social media use for news, network size, and network structure did not consistently predict political outcomes, they played significant roles in influencing different engagement in the three political systems. The comparative approach used in this study helped to demonstrate the role of social media in the democratic engagement of youth in three places with similar cultures but different political contexts.     

ADVERTISING AND VALUE MAXIMIZATION: AN INTEGRATIVE APPROACH *

The model developed in this paper is interdisciplinary in that we incorporate the advertising decision into the capital asset pricing model (CAPM) for valuation of risky income streams. The advertising decision involves the purchase of media services whose effects on sales (profit) are hypothesized to vary with general economic activity. As in any asset expansion, the firm purchases an income distribution with a given expected value and covariance with the economy. By consulting the CAPM, we are able to obtain a value for the income distribution associated with the advertising expenditure. By failing to account for both risk and return, those previous studies which have examined the effect of advertising on profit or valuation are, at best, incomplete. We are able to demonstrate the inappropriateness of ranking alternative advertising strategies solely on the basis of expected income.     

The Effect of Women’s Empowerment in Agriculture on Household Nutrition and Food Poverty in Northern Ghana

The study examines the effect of women’s empowerment in agriculture on household nutrition—i.e. the availability of carbohydrates, protein, and fat—and household food poverty measured by monetary food shortfall. The analysis is done by applying instrumental variable estimation to a sample of 2642 households from a 2012 population-based survey conducted in northern Ghana. Overall, the results indicate that women’s empowerment positively influences nutrient availability and negatively influences monetary food shortfall. By decomposing women’s empowerment into its component domains, this study identified that the domains of Income, Production, and Leadership are areas for intervention to influence households’ nutrient availability and monetary food shortfall outcomes. The effect of the Time and Resources domains reveal that some intra-household trade-offs may exist. Thus, policies aimed at empowering women to ultimately improve household nutrition and food poverty need to be based on the understanding of these specific interactions.     

Handwheel valve operation: assessment of four opening methods in terms of muscle loading, perceived comfort, and efficiency

Injuries due to manual valve handwheel operations are a major concern in the chemical process industry. Manual valves are used to start, stop, and control flow in process lines. The torque required to operate handwheels after the initial "breaking" can vary due to the size, design, and condition of the valve. This study tested four methods of turning the handwheel on a medium-sized gate valve at two different torque requirements (25 Nm and 50 Nm). The methods were compared to each other, in terms of efficiency, subjective ratings of perceived exertion, and electromyography activity of the upper extremity and trunk muscles. The results indicate that different methods and torque requirements are compensated for by the use of different muscles. Also, this use of different muscles, along with the increased mechanical advantage of the wrench, can affect the operator's actual and perceived comfort and efficiency while operating a valve handwheel.     

论声调语言的节奏与重音模式

声调语言的重音及其实现方式一直存在广泛争议,节奏角度可以为此问题带来新的研究思路。nPVI节奏模型主要反映相邻音节时长变化,作为声调语言,成都话的nPVI明显高于普通话,接近被视为重音计时型语言的英语,这与其重音凸显方式密切相关。成都话双音词和三音词的首音节大都具有时长重音,信息焦点也主要依靠时长凸显,有时还辅以焦点前压缩和助词延展。重音可以和声调共存,变调规律有时与重音实现直接相关,声调语言的节奏特征可以反映该语言中重音的作用大小和凸显度差异。