If you would like to re-publish ("self-archive") a journal article or another paper via the "Green Road" of Open Access in the Research Collection, you need to comply with the copyright policies of the original publisher.
Many publishing houses permit the publication of either preprints or postprints (also called Author's Accepted Manuscript, short AAM) of published articles in an institutional repository such as the Research Collection.
A preprint is the manuscript version of an article as submitted to the publisher, i.e. before peer review.
A postprint is the accepted manuscript after the peer review process. The postprint...
Publishing houses rarely allow the use of the publisher PDF for publication in a repository.
Some publishing houses only permit the publication of articles in repositories after a so-called embargo from the first publication date. This can vary from 2 to 36 months.
You can nevertheless submit your article at any time to the Research Collection. When uploading the file, indicate the embargo end date - your file will then be automatically made available to external users on this day while only metadata will be visible immediately.
The SHERPA/RoMEO database provides information on self-archiving guidelines of many scholarly journals and publishers.
Please consider however, that in case of doubt only those regulations actually stipulated in your publishing contract (Copyright Transfer Agreement, Licence to Publish) are legally binding.
In the absence of a publishing contract, the publisher's general terms and conditions apply.
The following example of an entry in SHERPA/RoMEO for the journal "Advances in Intelligent Systems and Computing" tells you that...