-- Database schema
| Author : Id [ INTEGER ] primary_key , Name [ TEXT ] , Affiliation [ TEXT ] | Conference : Id [ INTEGER ] primary_key , ShortName [ TEXT ] , FullName [ TEXT ] , HomePage [ TEXT ] | Journal : Id [ INTEGER ] primary_key , ShortName [ TEXT ] , FullName [ TEXT ] , HomePage [ TEXT ] | Paper : Id [ INTEGER ] primary_key , Title [ TEXT ] , Year [ INTEGER ] , ConferenceId [ INTEGER ] Paper.ConferenceId = Conference.Id , JournalId [ INTEGER ] Paper.JournalId = Journal.Id , Keyword [ TEXT ] | PaperAuthor : PaperId [ INTEGER ] PaperAuthor.PaperId = Paper.Id , AuthorId [ INTEGER ] PaperAuthor.AuthorId = Author.Id , Name [ TEXT ] , Affiliation [ TEXT ] |
-- -- How many authors finished the paper "An Improved Active Suspension Model for Attitude Control of Electric Vehicles" together?

SELECT COUNT(T2.AuthorId) FROM Paper AS T1 INNER JOIN PaperAuthor AS T2 ON T1.Id = T2.PaperId WHERE T1.Title = 'An Improved Active Suspension Model for Attitude Control of Electric Vehicles';