Patent ID: 11914448
Assignee: TOHOKU UNIVERSITY
Field: Computer technology (Electrical engineering)
Classification: CPC G  Y | IPC G

Claim 17:
18. A clustering method, comprising:
a batch process step of obtaining an optimum number of clusters from evaluation scores obtained by classifying all element data into clusters while changing a number of clusters to evaluate classification results for each of the number of clusters, obtaining a classification result of classifying all element data into clusters with the optimum number of clusters, and causing switching between enabling and disabling a latch operation of at least one pair of cells respectively provided in two register sections, whereby the circuit controls the latch operation of the at least one pair of the cells concurrently;
an update process step of assigning, upon addition of new element data after the batch process step, the new element data to one of existing clusters, and calculating an evaluation score for evaluating a classification result after assigning the new element data to the one of the existing clusters; and
a determining step of determining validity of the classification result in the update process step, based on the evaluation score calculated in the update process step, wherein
calculating the evaluation score or each of the evaluation scores comprises:
calculating a degree of internal compactness that is a first sum of values, each being defined by normalizing a first index value by a first value that is based on a number of element data within each cluster, the first index value indicating a degree of dispersion of element data within each cluster;
calculating a degree of external separation defined by normalizing a second sum of second index values for each cluster by a second value that is based on the number of clusters, each of the second index values indicating an index of a distance between the clusters; and, calculating the evaluation score or each of the evaluation scores according to a predetermined formula defined by the degree of internal compactness and the degree of external separation which are variables.