Due to typesetting mistake, unfortunately a phrase has been placed incorrectly.

On page 14, the line "Therefore, the query submitted by the application is a triplet P indicates a set of triples of [property, value, operation] determining the user-specifed conditions of the query, and O includes a set of felds as the output of the query. (T,P, O) where T denotes a set of target transaction types,"

Should instead read

"Therefore, the query submitted by the application is a triplet (T, P, Q) where T denotes a set of target transaction types, P indicates a set of triples of [property, value, operation] determining the user-specified conditions of the query, and O includes a set of fields as the output of the query."

The Publisher apologizes for the mistake. The original article has been corrected.