OJS distinguishes between "user" accounts and "author" entries. When you submit the metadata for an article, i.e. when you enter the author names, you're creating author entries; those, however, don't correspond to "user" accounts, which include usernames and passwords that people can use to log into the system. Those must be created separately.
When you submitted your articles, you probably used the import/export tools, or the QuickSubmit plugin, or enrolled your editor as an author and had them go through the process. Whichever approach you used, you'll have associated the submission with your manager or editor, not the author. The authors themselves won't even have logins to the system.
Your first task will be to create user accounts for the authors. You can do this manually (e.g. as the Journal Manager, using the "Create User" tool) or via XML import/export (as Journal Manager from Import/Export).
Second, you'll need to change the existing associations between articles and users. There is no way to do this in OJS; you'll need to do it by changing the database. The column you need to change is the "user_id" column in the "articles" table. It refers to the "users" table.
Public Knowledge Project Team