Added section on parameterized PRAM.

parallel.tex

@@ -77,6 +77,15 @@ \subsection{Memory access complexity}
   In the meantime, a brief description of memory access complexity can be found in \cite[Section~4.3]{zcsm07}.
 \end{todo}
 
+\subsection{Parameterized parallel random access machine}
+
+The Parameterized PRAM (PPRAM) defined in \cite{hc} is a general family of PRAM models which assign a different cost to each unique type of operation.
+Several other PRAM-like models are special cases of this generalization.
+
+The PPRAM is parameterized by a four-tuple of positive real values, $(\alpha, \beta, \gamma, \delta)$, which are the costs for EREW memory access, CRCW memory access, multiprefix operation (for example, a ``prefix-sum'' operation), and global synchronization, respectively.
+(Local computation has a cost of one.)
+The benefit of this parameterized model is that one can analyze the tradeoffs in resource usage due to differences in distinct algorithms for a single computational problem.
+
 \subsection{Other models of parallel computation}
 
 There are many, many other models of parallel computing machines; see \cite{zcsm07} for details and a listing of modern parallel computation models.

references.bib

@@ -345,3 +345,9 @@ @article{rs92
   ee        = {http://dx.doi.org/10.1007/BF01758779},
   bibsource = {DBLP, http://dblp.uni-trier.de}
 }
+
+@misc{hc,
+    author = {Timothy J. Harris and Murray I. Cole},
+    title = {The Parameterized PRAM},
+    year = {}
+}