Fuzzy logic and support vector machine approaches to regime identification in JET

Andrea Murari, Guido Vagliasindi, Maria Katiuscia Zedda, Robert Felton, C. Sammon, Luigi Fortuna, Paolo Arena

Research output: Contribution to journalArticle

16 Citations (Scopus)


A plasma regime is a distinct type of plasma confinement, which can be identified from several conventional plasma diagnostic signals. An accurate and general regime identifier is considered an important tool for future real time applications in Joint European Torus (JET). In this perspective, a traditional approach based on Discriminant Analysis was tested, using various sets of JET real time signals. Unfortunately, no combination of signals managed to provide a success rate higher than 90%. To improve the performance and increase the generalization capability, an identifier based on Fuzzy Logic was developed, which allowed inclusion of the time evolution of the Dα, a quantity normally not exploited by more traditional solutions. With this technique a success rate of 95% was achieved using only Dαand the derivative of betaN diamagnetic as inputs. A support vector machines approach, based again on a suitably defined distance like discriminant analysis, provided slightly inferior results with exactly the same inputs but matched the fuzzy logic method with the inclusion of the absolute value of βNdiamagnetic. This comparative performance assessment of the various methods is an important first step on the route to identify the best solution for a regime identifier for JET and in due course for ITER. © 2006 IEEE.
Original languageEnglish
Pages (from-to)1013 - 1020
Number of pages8
JournalIEEE Transactions on Plasma Science
Issue number3 PART 3
Publication statusPublished - 2006
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Murari, A., Vagliasindi, G., Zedda, M. K., Felton, R., Sammon, C., Fortuna, L., & Arena, P. (2006). Fuzzy logic and support vector machine approaches to regime identification in JET. IEEE Transactions on Plasma Science, 34(3 PART 3), 1013 - 1020. https://doi.org/10.1109/TPS.2006.875825