A Comparison of Hierarchical Methods for Clustering Functional Data

Functional data analysis (FDA)—the analysis of data that can be considered a set of observed continuous functions—is an increasingly common class of statistical analysis. One of the most widely used FDA methods is the cluster analysis of functional data; however, little work has been done to compare the performance of clustering methods on functional data. In this article, a simulation study compares the performance of four major hierarchical methods for clustering functional data. The simulated data varied in three ways: the nature of the signal functions (periodic, non periodic, or mixed), the amount of noise added to the signal functions, and the pattern of the true cluster sizes. The Rand index was used to compare the performance of each clustering method. As a secondary goal, clustering methods were also compared when the number of clusters has been misspecified. To illustrate the results, a real set of functional data was clustered where the true clustering structure is believed to be known. Comparing the clustering methods for the real data set confirmed the findings of the simulation. This study yields concrete suggestions to future researchers to determine the best method for clustering their functional data.     

新型现代农业技术推广困境的话语分析——以水稻强化栽培体系（SRI）在四川省Y村的推广为例

文章从水稻强化栽培体系在四川省Y村推广初期取得良好效果之后未能得到可持续应用的现象出发,以SRI为例分析了导致新型现代农业技术话语弱化的因素及其对新型现代农业技术推广和应用产生的不利影响.研究发现,推广主体权力的弱化和农户对知识体系的模糊性认识导致新型现代农业技术无法建构起有效的话语,而农民在考虑到技术“比较效益”之后选择的外出务工和“消遣经济”的道路,则进一步弱化了新型现代农业技术话语,同时,也对我国农业经济的发展和进步造成了严重影响.     

No Matter What: A Qualitative Analysis of How LGBTQ Families and Allies Define Family through an Interactive Art Project

ABSTRACT

The current study solicits individuals’ artistic depictions and written definitions of family and provides comparisons to existing conceptualizations of family in communication research. Attendees of a Midwestern pride festival took part in an interactive art display, creating a visual representation of their own family on one side of a card and writing their definition of family on the other side. Both images and definitions focused on the ways family members’ behaviors construct family. Participants’ written responses describe family as unconditional, particularly in terms of love, support, and acceptance.     

Unspanned Macroeconomic Factors in the Yield Curve

In this article, we extract common factors from a cross-section of U.S. macro-variables and Treasury zero-coupon yields. We find that two macroeconomic factors have an important predictive content for government bond yields and excess returns. These factors are not spanned by the cross-section of yields and are well proxied by economic growth and real interest rates.     

Approximate Bayesian computation with composite score functions

Both approximate Bayesian computation (ABC) and composite likelihood methods are useful for Bayesian and frequentist inference, respectively, when the likelihood function is intractable. We propose to use composite likelihood score functions as summary statistics in ABC in order to obtain accurate approximations to the posterior distribution. This is motivated by the use of the score function of the full likelihood, and extended to general unbiased estimating functions in complex models. Moreover, we show that if the composite score is suitably standardised, the resulting ABC procedure is invariant to reparameterisations and automatically adjusts the curvature of the composite likelihood, and of the corresponding posterior distribution. The method is illustrated through examples with simulated data, and an application to modelling of spatial extreme rainfall data is discussed.     

Association of sexual abstinence in adolescence with mental health in adulthood

We examined whether adolescent sexual abstinence predicts better adult mental health. 1,917 adolescents, recruited from middle schools at age 13, were surveyed at ages 13, 18, 23, and 29. In bivariate analyses, adolescent sexual abstinence was associated with better mental health at age 29 for females, but not males; three adolescent factors, educational prospects, family bonding, and unconventionality were investigated as explanatory variables of this relationship. The abstinence-mental health relationship was nonsignificant when educational prospects was included in multivariate models, and marginally significant when family bonding and unconventionality were included; all three explanatory factors accounted for significant proportions of the variance in adult mental health. Girls who are uninvolved in school, have weak family backgrounds, and exhibit unconventionality may have poor adult mental health, whether or not they abstain from sex in adolescence. Interventions that strengthen adolescents' connections to families and schools may reduce risk for long-term mental health problems.     

Does the Theory of Voluntary Sector Failure Provide Insight into Food Pantries? A Case Study of a Network of Food Pantries in San Diego,CA

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Individuals seek food assistance from both government and nongovernmental services. The theory of voluntary sector failure...     

Growing up on the sidelines: identity negotiations of Palestinian youth from ‘collaborating’ families relocated to Israel

By examining the experiences of the children of Palestinian collaborators whose families have relocated to Israel, this study explores how youth negotiate self within the context of marginalisation and cultural dislocation. Due to the actions of their parents, the research participants have become outsiders and outcasts in their Palestinian communities of origin, outsiders in Israel, and outsiders among Israeli-Arabs. Based on qualitative, in-depth interviews with 11 Palestinian male youths, we describe and analyse the experience of identity negotiation in the context of fear and their families’ past deceit. Our findings highlight that the youths’ identities are negotiated by engaging in a dialogue of self on belonging and not belonging that is based on visions of their past, present and future selves. This is accompanied by a forced dialogue with others, explaining who they are in order to fit in with the ‘audience’, a presentation that is then acted out.     

Using Qualitative Methods with Poor Children in Urban Ethiopia: Opportunities &; Challenges

This paper discusses the advantages and challenges of using qualitative methods to elicit poor children’s perspectives about threats and positive influences on their wellbeing. It draws on research carried out by the author on the subjective experiences of poor children in Addis Ababa, the capital of Ethiopia in terms of their understandings of wellbeing, threats to their wellbeing, coping strategies, and positive or resilient outcomes. After a brief introduction reviewing previous approaches to child poverty in general and research on Ethiopian children in particular, the second section describes the research setting and the ethical approach to the study, which influenced how consent was obtained and the data analysed. The paper then describes the use of qualitative methods such as semi-structured interviews, draw-and-tell, and diaries, the kinds of data they produced and the methodological and ethical dilemmas and tensions encountered in using them. It concludes that despite the challenges qualitative methods are invaluable in order to understand what poor children see as threats and positive influences on their wellbeing.