It is well-known that the estimated GARCH dynamics exhibit common patterns. Starting from this fact we extend the Dynamic Conditional Correlation (DCC) model by allowing for a clustering structure of the univariate GARCH parameters. The model can be estimated in two steps, the first devoted to the clustering structure, and the second focusing on correlation parameters. Differently from the trad...

Spectral clustering consists of two distinct stages: (a) construct an affinity graph from the dataset and (b) cluster the data points through finding an optimal partition of the affinity graph. The focus of the paper is the first step. Existing spectral clustering algorithms adopt Gaussian function to define the affinity graph since it is easy to implement. However, Gaussian function is hard to...

In this paper we give a complete classification of two-step nilpotent Leibniz algebras in terms Kronecker modules associated with pairs bilinear forms. particular, describe the complex and real case indecomposable Heisenberg as generalization classical $(2n+1)-$dimensional Lie algebra $\mathfrak{h}_{2n+1}$. Then use - local racks correspondence proposed by S. Covez to show that have always glob...