Multivariate techniques are used in this study to analyze the monitoring data displacements of a concrete dam, measured by means of pendulums, extensometer bases and multiple rod extensometers, taking into account the action of environmental conditions, bounded by the surface temperature of the concrete at ambient temperature and the tank water level. The canonical correlation analysis is used to evaluate the influence of environmental variables in the displacement of structures and dam foundations. The factor analysis is used to identify data sources of variability and order the sensors according to the action of factors. The dates of the measurements are grouped according to similarities in the present observations, by applying the cluster analysis. Then the discriminant analysis is used to assess the groups as to their homogeneity. The results demonstrate that the techniques used for distinguishing the dam responses and identify the effects of changes in environmental conditions on the displacements of the structures and dam foundations.
By establishing the bioerosion ichnogenus Oichnus, Richard Bromley (1981) addressed ‘small round holes in shells’ and catalysed a series of still ongoing discussions on ichnotaxonomical principles. In a recent revision by Zonneveld and Gingras (2014), Oichnus was rejected, together with Tremichnus Brett, 1985 and Fossichnus Nielsen, Nielsen and Bromley, 2003, by means of subjective synonymisation with the presumed senior synonym Sedilichnus Müller, 1977. However, Sedilichnus is nomenclaturally unavailable, because it is an atelonym (conditionally proposed). In addition, reinvestigation of the type material of ‘Sedilichnus’ shows that it probably describes variably shaped oscula and thus is a genuine morphological character of the host sponge Prokaliapsisjanus, rather than a bioerosion trace fossil. The ichnogenera Oichnus and Tremichnus are re vised, leading to the synonymisation of Balticapunctum Rozhnov, 1989 with Tremichnus, and of Fossichnus with Oichnus. The refined ichnogeneric diagnoses return Oichnus to complete or incomplete bioerosive penetrations in calcareous skeletal substrates, commonly interpreted as praedichnia with or without signs of attachment, while Tremichnus (now including O. excavatus) exclusively refers to shallow pits passing into echinoderm skeletons that are interpreted as domichnia or fixichnia.
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