A Note on Unicyclic Representations of Phase Type Distributions
نویسندگان
چکیده
In this note, we study the unicyclic representation introduced in O’Cinneide[21]. First, we present a counterexample to the conjecture that every PH -representation has an equivalent unicyclic representation of the same order. Then we show that the conjecture holds if the order of the PH -representation is 3. We also introduce an algorithm for computing a unicyclic generator of order 3, which PH -majorizes the original PH -generator, for any PH -generator of order 3. For the general case, we develop a nonlinear program for computing unicyclic representations for PH -distributions.
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