29.04.2013 Views

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

TESI DOCTORAL - La Salle

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

3.3. Deterministic hierarchical consensus architectures<br />

SERT DHCA (sec.)<br />

PERT DHCA (sec.)<br />

10 1<br />

10 0<br />

|df A | = 28 , |df D | = 14 , |df R | = 5<br />

ADR ARD DAR DRA RAD RDA flat<br />

DHCA variant<br />

10 0<br />

(a) Serial estimated running time<br />

|df A | = 28 , |df D | = 14 , |df R | = 5<br />

ADR ARD DAR DRA RAD RDA flat<br />

DHCA variant<br />

(c) Parallel estimated running time<br />

CSPA<br />

EAC<br />

HGPA<br />

MCLA<br />

ALSAD<br />

KMSAD<br />

SLSAD<br />

CSPA<br />

EAC<br />

HGPA<br />

MCLA<br />

ALSAD<br />

KMSAD<br />

SLSAD<br />

SRT DHCA (sec.)<br />

PRT DHCA (sec.)<br />

10 1<br />

10 0<br />

|df A | = 28 , |df D | = 14 , |df R | = 5<br />

ADR ARD DAR DRA RAD RDA flat<br />

DHCA variant<br />

10 0<br />

(b) Serial real running time<br />

|df A | = 28 , |df D | = 14 , |df R | = 5<br />

ADR ARD DAR DRA RAD RDA flat<br />

DHCA variant<br />

(d) Parallel real running time<br />

CSPA<br />

EAC<br />

HGPA<br />

MCLA<br />

ALSAD<br />

KMSAD<br />

SLSAD<br />

CSPA<br />

EAC<br />

HGPA<br />

MCLA<br />

ALSAD<br />

KMSAD<br />

SLSAD<br />

Figure 3.13: Estimated and real running times of the serial and parallel DHCA on the Zoo<br />

data collection in the diversity scenario corresponding to a cluster ensemble of size l = 1596.<br />

most numerous diversity factor to the first stage, the second most populated to the second<br />

DHCA stage, and so on) seems to give rise to the most computationally efficient serial<br />

DHCA variant. And secondly, the execution time of fully parallel DHCA appears to be<br />

pretty insensitive to the way diversity factors are associated to the stages of the hierarchical<br />

consensus architecture.<br />

In practice, these two latter facts may play down the accuracy of the computationally<br />

optimal consensus architecture prediction methodology presented in table 3.6, as it seems<br />

possible to make well-grounded aprioridecisions as regards the selection of the fastest<br />

deterministic hierarchical consensus architecture variant without need of any running time<br />

estimation. For this reason, the next section presents an exhaustive comparative evaluation<br />

of these two strategies for predicting the computationally optimal consensus architecture.<br />

Evaluation of the optimal DHCA prediction methodology based on running<br />

time estimation<br />

Following an analogous procedure as in section 3.2.4, we have computed the percentage of<br />

experiments in which the estimated and real running times are simultaneously minimized by<br />

the same consensus architecture. The impact of the failures of this prediction methodology is<br />

measured in terms of the absolute and relative differences between the real execution times<br />

–ΔRT– of the truly (i.e. the one minimizing SRTDHCA or PRTDHCA) and the allegedly<br />

(the one that minimizes SERTDHCA or PERTDHCA) computationally optimal consensus<br />

80

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!