L’orthographe lexicale des jeunes Français dans les discours des blogs

The aim of this study is to analyze and study French pupils spelling and more specificallyspelling errors. The study is based on the blogs of 78 young french students where spellingerrors are analyzed based on a typology by Nina Catach (1980). This typology explains whattype of spelling errors that can occur in the French language. La maitrise de l’orthographelexicale du français et de l’espagnol is a study made by Sony Mayard (2007) which explainsthe complexity of the French spelling.The study shows that first of all, the spelling of pupils is not something that can concretely bejudged or cataloged. You can never explain exactly why French pupils have an way ofspelling, since spelling is individual and takes several key factors in to consideration.However, this study presents one approach of how spelling errors can be differentiated andthe possible reasons why they are judged as incorrect.

Testing Seasonal Unit Roots in Data at Any Frequency, an HEGY approach

This paper generalizes the HEGY-type test to detect seasonal unit roots in data at any frequency, based on the seasonal unit root tests in univariate time series by Hylleberg, Engle, Granger and Yoo (1990). We introduce the seasonal unit roots at first, and then derive the mechanism of the HEGY-type test for data with any frequency. Thereafter we provide the asymptotic distributions of our test statistics when different test regressions are employed. We find that the F-statistics for testing conjugation unit roots have the same asymptotic distributions. Then we compute the finite-sample and asymptotic critical values for daily and hourly data by a Monte Carlo method. The power and size properties of our test for hourly data is investigated, and we find that including lag augmentations in auxiliary regression without lag elimination have the smallest size distortion and tests with seasonal dummies included in auxiliary regression have more power than the tests without seasonal dummies. At last we apply the our test to hourly wind power production data in Sweden and shows there are no seasonal unit roots in the series.

Testing for Seasonal Unit Roots when Residuals Contain Serial Correlations under HEGY Test Framework

This paper introduces a corrected test statistic for testing seasonal unit roots when residuals contain serial correlations, based on the HEGY test proposed by Hylleberg,Engle, Granger and Yoo (1990). The serial correlations in the residuals of test regressionare accommodated by making corrections to the commonly used HEGY t statistics. Theasymptotic distributions of the corrected t statistics are free from nuisance parameters.The size and power properties of the corrected statistics for quarterly and montly data are investigated. Based on our simulations, the corrected statistics for monthly data havemore power compared with the commonly used HEGY test statistics, but they also have size distortions when there are strong negative seasonal correlations in the residuals.