On the distribution of quadratic forms and applications in the analysis of repeated measurements

In this paper a unified approach is given to the distribution of scalar quadratic forms for dependent variables. Necessary and sufficient conditions are found for the sums of squares of the various hierarchical layers in ANOVA to be distributed as multiples of chi-square variables. Results concerning the usual univariate F-tests in ANOVA of repeated measurements are derived as a special case.     

Fuzzy Autoregressive Rules: Towards Linguistic Time Series Modeling

Fuzzy rule–based models, a key element in soft computing (SC), have arisen as an alternative for time series analysis and modeling. One difference with preexisting models is their interpretability in terms of human language. Their interactions with other components have also contributed to a huge development in their identification and estimation procedures. In this article, we present fuzzy rule–based models, their links with some regime-switching autoregressive models, and how the use of soft computing concepts can help the practitioner to solve and gain a deeper insight into a given problem. An example on a realized volatility series is presented to show the forecasting abilities of a fuzzy rule–based model.     

Language in the process of labour market rationalisation: A sociohistorical approach across twentieth-century Spain

This article analyses the role of linguistic skills in the process of defining professional classifications in Spain during 1919–1980. The aim is to determine the social evaluation of the skills involved. To retrace the classifications, a total of 114 official documents were examined, establishing a chronological division into three major stages: 1920–1940, 1940–1960 and 1960–1980. The first period (1920–1940) shows efforts toward the initial objectification of working conditions and salary scales, revealing social prejudices and tacit conventions shaping the employment hierarchy, while the second one (1940–1960) indicates the extent to which office work stood out over manual work. Finally, the third stage (1960–1980) shows processes of language rationalisation, which entailed attempts to standardise positions based on required skill sets.     

New configurations of labour insertion processes. The case of secondary technical and vocational education and training students in Chile

This article presents the results of a longitudinal study that followed a sample of 1011 young people who completed their secondary technical and vocational education and training studies in Chile between 2011 and 2016. It adopts a mixed design that combines both quantitative and qualitative methodological strategies to analyse transitions and post-study trajectories. Analysis has helped to identify the prevalence of non-linear and unstructured transitions to the labour market. It has also shown the existence of education-work links and employment alternatives that are generated in certain sectors as well as identified how these give rise to specific opportunity structures that affect on aspirations and career pathways. Results indicate that graduates of the industrial area of study experience more substantive educational integration and labour links following course completion due to greater levels of alignment between their training and the productive demands of the industrial sectors. However, their experiences over the medium term are fragmented and, thus, reflect those of their peers from other areas.