How do I cite same reference multiple times in a paper?
The most important principle to follow is that the source of the information that you are discussing should always be clear to a reader.  I thus find the following citation heuristics useful:


When you present a single statement in isolation, as in your example, each such statement should be individually cited.
When you are presenting a few statements in a chain, the first should have a citation, and the others be connected by prose.  For example:


  The Toast-o-matic processor has an unusual 19 bit word size [1].  It is also notable for its grilled cheese coprocessor and unusually high power demands.  Strong cooling is required, as the specifications note that its browning module is capable of attaining temperatures of more than 500F.

For larger contiguous blocks, such as a full paragraph or section, there should be an explicit delineation of the region covered by the citation.  For example:


  In this subsection, we briefly review the specifications of the Toast-o-matic processor[1].  The Toast-o-matic processor has an unusual 19 bit word size.  It is also notable...