Hi, anyone can confirm if a unique article first posted on author's site then submit the exact article to different article directories, will it be penalized?
Not a problem. If you submit to EA, and they reject your article, all you need to do is contact them and provide proof that that is your site. All the others don't care.
Not generally a problem at all. Almost all my articles are initially published and indexed on one of my own sites/blogs, then submitted (unamended/unedited) to Ezine Articles, and after that to other article directories. And the same's true for many of my clients. But if you do it that way round (which has many advantages), then to avoid explanations and delays, you do need to publish it first under the same name as the name/pen-name in which you later submit it to EZA.
Google is even relaxing on the duplication stuff lately. Where they would just negate the items and not search engine list them, now they are relaxing that too. There are good reasons for article duplication across domains. The penalties.. aren't actually penalties really.. Search engines handle it another way. googlewebmastercentral.blogspot.com/2008/09/demystifying-duplicate-content-penalty.html