Venue names are often inconsistent in such a manner. Even if you take your citations from a single source (e.g., DBLP), you will sometimes find different names for the same venue across different years.
When citing, the aims should be:
- Give enough information for a reader to unambiguously find a paper
- Give enough information for citation engines to unambiguously know which paper is cited
- Present the citations in the format required by the publisher
- Keep citations neat and consistent in style
With regards to this citation:
D. Bi-Ru and I. C. Lin, "Efficient Map/Reduce-Based DBSCAN Algorithm with Optimized Data Partition," in Cloud Computing (CLOUD), 2012 IEEE 5th International Conference on, 2012, pp. 59-66.
This seems to meet 1–3.
With regards 4, I would say it is not very neat. I would do:
D. Bi-Ru and I. C. Lin, "Efficient Map/Reduce-Based DBSCAN Algorithm with Optimized Data Partition," in IEEE 5th International Conference on Cloud Computing (CLOUD), 2012, pp. 59–66.
This reads more naturally, avoids repeating the year and uses an en-dash for the pages (okay, the later is being super-pedantic).
More correctly, you should probably have "in Proceedings of IEEE ..." but I always found that a waste of space.
If you're fighting a page limit, it is common practice to just write the abbreviation for well known conferences within the community (e.g., "CLOUD").
However you choose to format the venue, for the other conference/workshop citations, you should then include a similar style. In this case, all venues should include the edition (5th), the full title (International ...) and the abbreviation (CLOUD).
(And on a side note, I highly recommend switching to LaTeX/BiBTeX and pulling your citations from DBLP if you have medium-to-long term plans for researching in an area of Computer Science.)