The dystonias are movement disorders in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The movements, which are involuntary and sometimes painful, may affect a single muscle; a group of muscles such as those in the arms, legs, or neck; or the entire body.
Definition of Data Clustering. Data Clustering is the classification of a data set into a group of numbers, where members of each group surround a particular number.efinition of Data Clustering. Data Clustering is the classification of a data set into a group of numbers, where members of each group surround a particular number.
A cluster is a group of disk sectors. The operating system assigns a unique number to each cluster and then keeps track of files according to which clusters they use. Occasionally, the operating system marks a cluster as being used even though it is not assigned to any file. This is called a lost cluster. You can free up disk space by reassigning lost clusters, but you should first make sure that the clusters do not, in fact, contain valuable data.