Vector and recurrent singular spectrum analysis: which is better at forecasting?

Singular spectrum analysis (SSA) is an increasingly popular and widely adopted filtering and forecasting technique which is currently exploited in a variety of fields. Given its increasing application and superior performance in comparison to other methods, it is pertinent to study and distinguish between the two forecasting variations of SSA. These are referred to as Vector SSA (SSA-V) and Recurrent SSA (SSA-R). The general notion is that SSA-V is more robust and provides better forecasts than SSA-R. This is especially true when faced with time series which are non-stationary and asymmetric, or affected by unit root problems, outliers or structural breaks. However, currently there exists no empirical evidence for proving the above notions or suggesting that SSA-V is better than SSA-R. In this paper, we evaluate out-of-sample forecasting capabilities of the optimised SSA-V and SSA-R forecasting algorithms via a simulation study and an application to 100 real data sets with varying structures, to provide a statistically reliable answer to the question of which SSA algorithm is best for forecasting at both short and long run horizons based on several important criteria.     

Discourses about children's mental health and developmental disorders in North American women's magazines 1990–2012

This paper describes and analyses the portrayal of children's mental health and developmental issues (CMHI) in articles located in a random sample of a selection of available high‐circulating English language North American ‘women's magazines’ indexed in the Reader's Guide to Periodical Literature from 1990 to 2012. It is based upon a qualitative discourse analysis. CMHI are portrayed as materially, biologically real, prevalent and growing in incidence, and severity. They are also portrayed as located in the ‘non‐normal’, ‘non‐nice’, ‘disliked’ and ‘non‐successful’ individual child. Neither the facticity nor the biomedicalization of CMHI is questioned. The psy‐scientists and practitioners cited as experts for the ‘disorders’ offer contradictory and confusing information and advice. The possible theoretical and pragmatic explanations and consequences of this portrayal are discussed.     

How Does Divorce Affect Iranian Women's Sexual Well-Being?

Sexuality and divorce are two interwoven subjects with complex effects on women's sexual well-being in Iranian culture. Results of this exploratory study using focus group discussions and individual interviews revealed how the sexual well-being of women was influenced by the divorce experience through common patterns and recurring themes. A total of 26 women participated voluntarily in the study. They were approached through a selected social support group in a center in West Tehran in 2011, and all had been divorced for less than 10 years. For the majority, sexuality-related matters became complicated and jeopardized their overall well-being in postdivorce life. This finding, along with the fact that the majority were seeking financial and emotional support, implies that counseling women and providing economic support for postdivorce life might improve women's sexual well-being.     

Conservation technology adoption decisions and the theory of planned behavior

This study of water saving technology adoption and technology investment behavior for Florida strawberry farmers represents an application of the Theory of Planned Behavior. It is compared with the Theory of Reasoned Action, and the Theory of Derived Demand. The focus is on perceived control in the decisions, first, to become an adopter of conservation technology, and, second, to invest more capital in the technology. The results lend credence to the Planned Behavior Theory but also support Derived Demand Theory, in that actual financial capability (actual control) is found important. To predict technology adoption we may need to account for both perceived and actual control. Unfettered government control of farmer technology decisions could be counterproductive, suggesting technology policy may need to include a mix of moral suasion and incentives with more modest controls.     

Homogeneity test based on ranked set samples

Abstract

The homogeneity hypothesis is investigated in a location family of distributions. A moment-based test is introduced based on data collected from a ranked set sampling scheme. The asymptotic distribution of the proposed test statistic is determined and the performance of the test is studied via simulation. Furthermore, for small sample sizes, the bootstrap procedure is used to distinguish the homogeneity of data. An illustrative example is also presented to explain the proposed procedures in this paper.     

Exponential inequalities for the Robbins–Monro’s algorithm under mixing condition

Abstract

In this work, we establish exponential inequalities for the Robbins–Monro’s algorithm with ψ-mixing variables, and we give a result on the almost complete convergence rate.