Each article has a DOI (Digital Object Identifier) which may be used as a permanent URL to the article's abstract record (and the associated fulltext PDF).
Navigate to the article abstract, and look for the DOI near the top.
This number, preceded by "http://dx.doi.org/" will form a permanent URL to the article. Example: http://dx.doi.org/10.1109/MAHC.2009.31
For links to the publication, use "http://ieeexplore.ieee.org/servlet/opac?punumber=X" where X is replaced by the publication or PU number. A list of journal PU numbers is available on the IEEE website.
For links to a specific issue of a publication, use "http://ieeexplore.ieee.org/servlet/opac?punumber=X&isvol=Y&isno=Z" where X is replaced by the publication or PU number, Y is the volume number, and Z is the issue number.
Be sure to prefix with the "proxy prefix"