Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 이정표 | - |
dc.date.accessioned | 2019-11-30T15:44:18Z | - |
dc.date.available | 2019-11-30T15:44:18Z | - |
dc.date.issued | 2017-09 | - |
dc.identifier.citation | NUCLEAR FUSION, v. 57, no. 12, Article no. 126013 | en_US |
dc.identifier.issn | 0029-5515 | - |
dc.identifier.issn | 1741-4326 | - |
dc.identifier.uri | https://iopscience.iop.org/article/10.1088/1741-4326/aa8387 | - |
dc.identifier.uri | https://repository.hanyang.ac.kr/handle/20.500.11754/115540 | - |
dc.description.abstract | It 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 n(e) and T-e 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.description.sponsorship | The authors are very grateful for the clear description of the relationship between second derivatives and momentum transport provided by M. Barnes. This material is based upon work conducted using the Alcator C-Mod tokamak, a DOE Office of Science user facility. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Award Number DE-FC02-99ER54512. This material is based upon work supported in part by the U.S. Department of Energy Office of Science Graduate Research Fellowship Program (DOE SCGF), made possible in part by the American Recovery and Reinvestment Act of 2009, administered by ORISE-ORAU under contract number DE-AC05-06OR23100. | en_US |
dc.language.iso | en_US | en_US |
dc.publisher | IOP PUBLISHING LTD | en_US |
dc.subject | momentum transport | en_US |
dc.subject | Bayesian analysis | en_US |
dc.subject | Gaussian processes | en_US |
dc.subject | profile fitting | en_US |
dc.title | Experimentally testing the dependence of momentum transport on second derivatives using Gaussian process regression | en_US |
dc.type | Article | en_US |
dc.relation.no | 12 | - |
dc.relation.volume | 57 | - |
dc.identifier.doi | 10.1088/1741-4326/aa8387 | - |
dc.relation.page | 126013-126022 | - |
dc.relation.journal | NUCLEAR FUSION | - |
dc.contributor.googleauthor | Chilenski, M. A. | - |
dc.contributor.googleauthor | Greenwald, M. J. | - |
dc.contributor.googleauthor | Hubbard, A. E. | - |
dc.contributor.googleauthor | Hughes, J. W. | - |
dc.contributor.googleauthor | Lee, J. P. | - |
dc.contributor.googleauthor | Marzouk, Y. M. | - |
dc.contributor.googleauthor | Rice, J. E. | - |
dc.contributor.googleauthor | White, A. E. | - |
dc.relation.code | 2017003730 | - |
dc.sector.campus | S | - |
dc.sector.daehak | COLLEGE OF ENGINEERING[S] | - |
dc.sector.department | DEPARTMENT OF NUCLEAR ENGINEERING | - |
dc.identifier.pid | jungpyo | - |
dc.identifier.researcherID | E-4796-2018 | - |
dc.identifier.orcid | http://orcid.org/0000-0002-4382-4515 | - |
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