Euclidean distance is commonly involved in calculating functional diversity (FD), for example, in measures based on dendrogram branch lengths. We point out that this function is inappropriate in many cases and that the choice of clustering method is more crucial than earlier thought. Gower’s formula and UPGMA clustering are suggested here as a standard combination of techniques for calculating ...

We describe a new wavelet transform, for use on hierarchies or binary rooted trees. The theoretical framework of this approach to data analysis is described. Case studies are used to further exemplify this approach. A first set of application studies deals with data array smoothing, or filtering. A second set of application studies relates to hierarchical tree condensation. Finally, a third stu...

This paper introduces an innovative approach for detecting a suboptimal partition starting from the dendrogram produced by a hierarchical clustering techinique. The approach exploits permutation tests and it can be used regardless of the agglomeration method and distance measure used in the classification process because it relies on the same criteria used for producing it. Moreover, the propos...

In this paper, we are concerned with the problem of flooding undirected weighted graphs under ceiling constraints. We provide a new algorithm based on a hierarchical structure called dendrogram, which offers the significant advantage that it can be used for multiple flooding with various scenarios of the ceiling values. In addition, when exploring the graph through its dendrogram structure in o...

Clustering data has been of great interest to many researchers. Hierarchical clustering methods have been preferred because clusters can be visualized as a dendrogram. One of the problems of hierarchical clustering methods, however, is that the resulting dendrogram is not visually pleasing due to the scaling problem. Hence, a series of iterated logarithmic function is proposed so as to mitigate...

In this paper, we propose a framework, structured semantic space, as a foundation for word sense disarnbiguation tasks, and present a strategy to identify the correct sense of a word in some context based on the space. The semantic space is a set of multidimensional real-valued vectors, which formally describe the contexts of words. Instead of locating all word senses in the space, we only make...

Dendrograms are graphical representations of binary tree structures resulting from agglomerative hierarchical clustering. In Life Science, a cluster heat map is a widely accepted visualization technique that utilizes the leaf order of a dendrogram to reorder the rows and columns of the data table. The derived linear order is more meaningful than a random order, because it groups similar items t...