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dc.contributor.authorChilenski, Mark Alan
dc.contributor.authorGreenwald, Martin J
dc.contributor.authorHubbard, Amanda E
dc.contributor.authorHughes Jr, Jerry
dc.contributor.authorLee, J. P.
dc.contributor.authorMarzouk, Youssef M
dc.contributor.authorRice, John E
dc.contributor.authorWhite, Anne E.
dc.date.accessioned2018-04-04T16:06:08Z
dc.date.available2018-04-04T16:06:08Z
dc.date.issued2017-09
dc.date.submitted2017-02
dc.identifier.issn0029-5515
dc.identifier.issn1741-4326
dc.identifier.urihttp://hdl.handle.net/1721.1/114540
dc.description.abstractIt remains an open question to explain the dramatic change in intrinsic rotation induced by slight changes in electron density (White et al 2013 Phys. Plasmas 20 056106). One proposed explanation is that momentum transport is sensitive to the second derivatives of the temperature and density profiles (Lee et al 2015 Plasma Phys. Control. Fusion 57 125006), but it is widely considered to be impossible to measure these higher derivatives. In this paper, we show that it is possible to estimate second derivatives of electron density and temperature using a nonparametric regression technique known as Gaussian process regression. This technique avoids over-constraining the fit by not assuming an explicit functional form for the fitted curve. The uncertainties, obtained rigorously using Markov chain Monte Carlo sampling, are small enough that it is reasonable to explore hypotheses which depend on second derivatives. It is found that the differences in the second derivatives of and between the peaked and hollow rotation cases are rather small, suggesting that changes in the second derivatives are not likely to explain the experimental results.en_US
dc.publisherIOP Publishingen_US
dc.relation.isversionofhttp://dx.doi.org/10.1088/1741-4326/AA8387en_US
dc.rightsCreative Commons Attribution-Noncommercial-Share Alikeen_US
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/4.0/en_US
dc.sourceMIT Web Domainen_US
dc.titleExperimentally testing the dependence of momentum transport on second derivatives using Gaussian process regressionen_US
dc.typeArticleen_US
dc.identifier.citationChilenski, M.A. et al. “Experimentally Testing the Dependence of Momentum Transport on Second Derivatives Using Gaussian Process Regression.” Nuclear Fusion 57, 12 (September 2017): 126013 © 2017 IAEA, Viennaen_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Aeronautics and Astronauticsen_US
dc.contributor.departmentMassachusetts Institute of Technology. Plasma Science and Fusion Centeren_US
dc.contributor.mitauthorChilenski, Mark Alan
dc.contributor.mitauthorGreenwald, Martin J
dc.contributor.mitauthorHubbard, Amanda E
dc.contributor.mitauthorHughes Jr, Jerry
dc.contributor.mitauthorLee, J. P.
dc.contributor.mitauthorMarzouk, Youssef M
dc.contributor.mitauthorRice, John E
dc.contributor.mitauthorWhite, Anne E.
dc.relation.journalNuclear Fusionen_US
dc.eprint.versionAuthor's final manuscripten_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dc.date.updated2018-04-04T15:42:06Z
dspace.orderedauthorsChilenski, M.A.; Greenwald, M.J.; Hubbard, A.E.; Hughes, J.W.; Lee, J.P.; Marzouk, Y.M.; Rice, J.E.; White, A.E.en_US
dspace.embargo.termsNen_US
dc.identifier.orcidhttps://orcid.org/0000-0002-3616-8484
dc.identifier.orcidhttps://orcid.org/0000-0002-4438-729X
dc.identifier.orcidhttps://orcid.org/0000-0003-4802-4944
dc.identifier.orcidhttps://orcid.org/0000-0001-8242-3290
dc.identifier.orcidhttps://orcid.org/0000-0001-8319-5971
dc.identifier.orcidhttps://orcid.org/0000-0003-2951-9749
mit.licenseOPEN_ACCESS_POLICYen_US


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