4.4 Trade-Offs
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Note: each figure shows four graphs in the x-y-z format with the following
characteristics:
• Horizontal axis shows C1, R1 or WR1
• Vertical axis shows WC1 or WR1
• Within these axes, contour lines of IN Sefficiency (iSE) or OUT Sefficiency (cSE)
are drawn
• Each figure shows various graphs along C1, R1, WC1 or WR1. We give four out of
20 graphs, which seems to be sufficient to portray the patterns and the trade-offs.
For example, Fig. 4.6 gives WR1-WC1-iSE graphs with WR1 and WC1 axes
showing iSE contour lines for four fixed values of C1.
It should be mentioned that not all the combinations of the three variables (C1 or
R1, WC1, WR1) occur in practice, meaning that there are infeasible combinations
within each figure. However, the patterns and trade-offs given by the figures are valid
for the feasible combinations, and consequently, in the following discussions, we
will not be concerned about the feasibility of an example or case (i.e., one specific
Fig. 4.7 Contour lines of WR1-WC1-iSE trade-offs and patterns along four R1 values