2,744 research outputs found
A Probabilistic Linear Genetic Programming with Stochastic Context-Free Grammar for solving Symbolic Regression problems
Traditional Linear Genetic Programming (LGP) algorithms are based only on the
selection mechanism to guide the search. Genetic operators combine or mutate
random portions of the individuals, without knowing if the result will lead to
a fitter individual. Probabilistic Model Building Genetic Programming (PMB-GP)
methods were proposed to overcome this issue through a probability model that
captures the structure of the fit individuals and use it to sample new
individuals. This work proposes the use of LGP with a Stochastic Context-Free
Grammar (SCFG), that has a probability distribution that is updated according
to selected individuals. We proposed a method for adapting the grammar into the
linear representation of LGP. Tests performed with the proposed probabilistic
method, and with two hybrid approaches, on several symbolic regression
benchmark problems show that the results are statistically better than the
obtained by the traditional LGP.Comment: Genetic and Evolutionary Computation Conference (GECCO) 2017, Berlin,
German
H2O contents and hydrogen isotopic composition of apatite crystals from L, LL5-6 ordinary chondrites.
第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月30日(金) 国立国語研究所 2階講
11C-Labeling of Indolealkylamine Alkaloids and the Comparative Study of Their Biodistributions
開始ページ、終了ページ: 冊子体のページ付
Preservation of Glucose Metabolism in Caudate Region at the Terminal Stage of Late-Infantile Neuronal Ceroid-Lipofuscinosis
開始ページ、終了ページ: 冊子体のページ付
Absolute value measurement of ion-scale turbulence by two-dimensional phase contrast imaging in Large Helical Device
Absolute value measurements of turbulence amplitude in magnetically confined
high-temperature plasmas can effectively explain turbulence-driven transport
characteristics and their role in plasma confinements. Two-dimensional phase
contrast imaging (2D-PCI) is a technique to evaluate the space-time spectrum of
ion-scale electron density fluctuation. However, absolute value measurement of
turbulence amplitude has not been conducted owing to the nonlinearity of the
detector. In this study, the absolute measurement method proposed in the
previous study is applied to turbulence measurement results in the large
helical device. As a result, the localized turbulence amplitude at
m is approximately m,
which is 0.02\% of the electron density. In addition, the evaluated poloidal
wavenumber spectrum is almost consistent, within a certain error range, the
spectrum being calculated using a nonlinear gyrokinetic simulation. This result
is the first to the best of our knowledge to quantitatively evaluate turbulence
amplitudes measured by 2D-PCI and compare with simulations
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