Recently published paper does not cite my very relevant work Before I start my PhD I worked in a group that researched on the application of a particular area to a particular domain. No other research group published work in this area+domain. So I can safely say that my previous group is among the first if not the first to research in the application of that particular research area on that particular domain. 

Now I find a paper published at an IEEE conference where a major part of its contribution is introducing a system that does something I did in a previously published paper, and it does it in the exact same way and even gives it the same name! 

I know that some conferences could accept non-novel contributions. Also the paper talks about other aspects so I find it perfectly fine that this paper has been accepted and published. But what I find annoying is that they do not cite my relevant work which was published a year earlier and fairly visible online; A simple (unpersonalized) search on Google would show up at least three links to my work. 

This is the second time I face this problem, but the first time this happened it was actually by the same group I worked with before; they published a related paper without citing the paper I co-authored with them. 

I try to give the maximum possible exposure to my work by making it publicly available on my personal website, ResearchGate, making sure it appears on Google Scholar, etc.. 

I find it worrying that my work misses citations, I am keen on improving my h-index and citations count. So my questions are:


Is there anything I can do regarding that already-published paper? 
Is there anything I can do to prevent this from happening in the future?
That happens. Maybe they didn't do a thorough literature study before they published, or they did but before your work was available. This is more frequent than we would like to think. Note that it's generally expected from authors to have done a reasonable effort in searching for previous work, but it's not unethical per se not to reference every previous publication that could be relevant (it's also practically very hard).


  Is there anything I can do regarding that already-published paper?


No, missing a previous related work is not a valid motivation to complain to the authors or editors. Just forget about it and move on. 


  Is there anything I can do to prevent this from happening in the future?


Yes, become so influential in your field that reviewers will know your work enough to spot when someone else submit a related work without citing yours.

Side note:


  I am keen on improving my h-index and citations count.


Without going into how this might not be what you should focus on (while very good researchers tend to have a high citation count, the inverse relation is not always true), the best way to do that is to produce high-quality research, preferably on a hot research topic.