27 research outputs found
Using fish assemblages in different habitats to develop a management plan for the Upper Essequibo Conservation Concession, Guyana
Significance testing of a cluster of multivariate binary variables: comparison of the tripartite T index to three common similarity measures
Revision of Amanita alexandri and its similarity to Amanita polypyramis
Amanita polypyramis and Amanita alexandri are easily confused species of Amanita section Lepidella. The holotype of the latter taxon was studied, as well as of other collections of the two species. No significant difference between these taxa were found. Amanita alexandri is proposed to be a posterior taxonomic synonym of A. polypyramis
Toxicity of muscimol and ibotenic acid containing mushrooms reported to a regional poison control center from 2002–2016
Sector classification through non-Gaussian similarity
Standard sector classification frameworks present drawbacks that might hinder portfolio managers. This article introduces a new nonparametric approach to equity classification. Returns are decomposed into their fundamental drivers through Independent Component Analysis (ICA). Stocks are then classified according to the relative importance of the identified fundamental drivers for their returns. A method is developed permitting the quantification of these dependencies, using a similarity index. Hierarchical clustering allows for grouping the stocks into new classes. The resulting classes are compared with those from the two-digit Global Industry Classification System (GICS) for US blue chip companies. It is shown that specific relations between stocks are not captured by the GICS framework. The method is tested for robustness and successfully applied to portfolio management.