27 citations · 62 across the 10 of their papers we have counts for
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Principal Geodesic Analysis applied to climate time series
Nozomi Sugiura
Principal Geodesic Analysis (PGA) is applied to a climate time series. First, we transform each multidimensional sequence into the path signature. Since the signature lives in a cu…
The Onsager--Machlup functional for data assimilation
Nozomi Sugiura
When taking the model error into account in data assimilation, one needs to evaluate the prior distribution represented by the Onsager--Machlup functional. Through numerical experi…
A framework for interpreting regularized state estimation
Nozomi Sugiura, Shuhei Masuda, Yosuke Fujii +3
Four-dimensional variational data assimilation (4D-Var) on a seasonal-to-interdecadal time scale under the existence of unstable modes can be viewed as an optimization problem of s…
Coarse-grained sensitivity for multiscale data assimilation
Nozomi Sugiura
We show that the effective average action and its gradient are useful for solving multiscale data assimilation problems. We also present a procedure for numerically evaluating the…