Connection tables information content

As with the numeric data, the content of stmctural information in the secondary literature is fimited, and we therefore have a situation in which many specicdised systems have been developed to deal with stractural data. Files of chemical stractures, and means of accessing them, have been with us for a number of years, certainly from before computers. Traditionally, these have used notations, fragment codes, etc., as the means of recording structural information, and have allowed searches to be made for complete compounds or for all compounds containing certain specified substractures. More recently, topographical systems have been developed. In these the complete stractures are recorded in the form of "connection tables", which store full details of all the atoms and bonds in a molecule, and the precise arrangement in which they are connected. 

Development of Search Keys. An analysis was made of previous DTP searches (16), and keys were developed that would make effective use of the detailed Information content of the CAS Registry III connection table. Although some thought was given to developing novel substructure search keys, the reality of our development schedule led to the use of a combination of previously developed key types that have been found efficient. Figure 4 shows a mythical example of an abbreviated DTP structure record and sample of each type of search key. A description of each follows. 

For each TCP/IP connection, 41 various quantitative and qualitative features were extracted. Table 2 shows the list of 41 features of the data [14], This features can be divided into three categories intrinsic features, i.e., general information related to the connection traffic features, i.e., statistics related to past connections similar to the current one e.g., number of connections with the same destination host or connections related to the same service in a given time window or within a predefined number of past connections content features, i. e., features containing information about the... 

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