Self-organizing maps, SOMs, are a data visualization technique developed to reduce the dimensions of data through the use of self-organizing neural networks. However, as the original input manifold can be complicated with an inherent dimension larger than that of the feature map, the dimension reduction in SOM can be too drastic, generating a folded feature map. In order to eliminate this pheno...

Some dynamical properties for a dissipative kicked rotator are studied. Our results show that when dissipation is taken into account a drastic change happens in the structure of the phase space in the sense that the mixed structure is modified and attracting fixed points and chaotic attractors are observed. A detailed numerical investigation in a two-dimensional parameter space based on the beh...

When recording data, large errors may occur occasionally. The corresponding abnormal data points, called outliers, can have drastic effects on the estimates. There are several ways to cope with outliers 0 detect and delete or adjust the erroneous data, use a modified cost function. We propose a new approach that allows, by introducing additional variables, to model the outliers and to detect th...

In this paper we investigate the impact of the switching from the same-day settlement to the following-day settlement on the market volatility and its structure. Using the Levene tests and bootstrap procedures, we find that the switching causes a drastic decrease in the stock market volatility. In addition, using a modified GARCH model, we also find a substantial change in the volatility struct...