entity relationship
1.An OOA model may be expressed informally in diagrams or text, or more formally in entity-relationship (ER) diagrams, data-flow diagrams, state-transition diagrams, or a variety of specialty representation currently available.
2.On the other hand, the special feature of electronic signature gives rise to another new legal relationship: online certification service relationship, which stemmed out of the verification service provided by a special entity in respect of the genuineness of electronic signatures and signatories.
