Theology and cosmology beyond the Big Bang theory

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Forecasts for the Canadian Lynx time series using method that bombine neural networks, wavelet shrinkage and decomposition

Time series forecasting is widely used in various areas of human knowledge, especially in the planning and strategic direction of companies. The success of this task depends on the forecasting techniques applied. In this paper, a hybrid approach to project time series is suggested. To validate the methodology, a time series already modeled by other authors was chosen, allowing the comparison of results. The proposed methodology includes the following techniques: wavelet shrinkage, wavelet decomposition at level r, and artificial neural networks (ANN). Firstly, a time series to be forecasted is submitted to the proposed wavelet filtering method, which decomposes it to components of trend and linear residue. Then, both are decomposed via level r wavelet decomposition, generating r + 1 Wavelet Components (WCs) for each one; and then each WC is individually modeled by an ANN. Finally, the predictions for all WCs are linearly combined, producing forecasts to the underlying time series. For evaluating purposes, the time series of Canadian Lynx has been used, and all results achieved by the proposed method were better than others in existing literature

Collective bargaining and regional wage differences in Spain: an empirical analysis

This article analyses the importance of labour market institutions and, in particular, collective wage bargaining in shaping regional wage differences in the Spanish labour market. Using microdata from the Spanish Structure of Earnings Survey, our results reveal that there are significant inter-regional wage differences for similarly skilled workers. These differences are present throughout the whole wage structure and can be explained by both competitive and non-competitive factors, such as insufficient competition in product markets. In this context, industry-level collective bargaining plays a major role in accounting for regional wage differences, a role that in the Spanish case is enhanced due to its unusual regional dimension.