Clusters classification

Electron-precise, electron-deficient and electron-rich clusters. A cluster classification often adopted in several books, and related to the rules previously presented, corresponds to a subdivision into three categories electron-precise, electron-deficient and electron-rich types. The electron-precise clusters may be considered as reference structures. 

In our study we compare two diversity-driven design methods (uniform cell coverage and clustering), two analysis methods motivated by similarity (cell-based analysis and cluster-classification), and two descriptor sets (BCUT and constitutional). Thus, our study addresses some of the many questions arising in a sequential screen how to choose the initial screen, how to analyze the structure-activity data, and what molecular descriptor set to use. The study is limited to one assay and thus cannot be definitive, but it at least provides preliminary insights and reveals some trends. 

Here we compare cluster classification (Subheading 3.1.) and cell-based analysis (CBA, Subheading 3.2.) in terms of the number of hits found in the test data. 

Table 5 provides analogous performance results for cluster-classification. Each test compound is assigned to the nearest cluster. If the cluster is active,... 

Young and Hawkins have analyzed the same dataset using recursive partitioning and the same designs from the training data. Comparison with their results reported in Chapter 12 suggests that both cluster classification and CBA are competitive with recursive partitioning as predictors of active compounds. 

This work was funded by MITACS and NSERC of Canada. We thank Hugh Chipman, Geoffrey Salloum, and Xu Wang for their help with the cluster-classification method and Stan Young for valuable discussions and contributions to this work. 

Berry MW, Castellanos M (eds) (2007) Survey of text mining clustering, classification, and retrieval. Springer... 

Each cluster is keyed to curriculum choice, occupation and job information. For each cluster, users can obtain information on related educational fields and courses, related occupations and job contexts, skills and abilities needed in the jobs, and suggested activities to get experience. At this level of exploration, assessment of values or of abilities can be also conceived, taking into consideration the mentioned career clusters classification. 

Table 13.11 Cluster classification of coatings for use in a QCM sensor array...

A system of simple identical mathematical functions, that working in parallel yield a multi-response answer Y = (yi, yz,..., yn) for each multi-variate input X = (xi,X2,..., Xm), which can be applied to a variety of chemical problems such as clustering, classifications, mapping, modeling, etc. 

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