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Luminosity function of faint sporadic meteors measured with a wide-field CMOS mosaic camera Tomo-e PM

Imaging observations of faint meteors were carried out on April 11 and 14, 2016 with a wide-field CMOS mosaic camera, Tomo-e PM, mounted on the 105-cm Schmidt telescope at Kiso Observatory, the University of Tokyo. Tomo-e PM, which is a prototype …

Superresolution interferometric imaging with sparse modeling using total squared variation -- Application to imaging the black hole shadow

We propose a new imaging technique for interferometry using sparse modeling, utilizing two regularization terms: the $\ell_1$-norm and a new function named total squared variation (TSV) of the brightness distribution. First, we demonstrate that our …

``Slow-scanning'' in ground-based mid-infrared observations

Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a …

Exhaustive search for sparse variable selection in linear regression

We propose a $K$-sparse exhaustive search (ES-$K$) method and a $K$-sparse approximate exhaustive search method (AES-$K$) for selecting variables in linear regression. With these methods, $K$-sparse combinations of variables are tested exhaustively …

Accelerating cross-validation with total variation and its application to super-resolution imaging

We develop an approximation formula for the cross-validation error (CVE) of a sparse linear regression penalized by $\ell_1$-norm and total variation terms, which is based on a perturbative expansion utilizing the largeness of both the data …

Imaging the Schwarzschild-radius-scale Structure of M87 with the Event Horizon Telescope using Sparse Modeling

We propose a new imaging technique for radio and optical/infrared interferometry. The proposed technique reconstructs the image from the visibility amplitude and closure phase, which are standard data products of short-millimeter very long baseline …

Superresolution full-polarimetric imaging for radio interferometry with sparse modeling

We propose a new technique for radio interferometry to obtain superresolution full-polarization images in all four Stokes parameters using sparse modeling. The proposed technique reconstructs the image in each Stokes parameter from the corresponding …

Data compression for the Tomo-e Gozen using low-rank matrix approximation

Optical wide-field surveys with a high cadence are expected to create a new field of astronomy, so-called "movie astronomy," in the near future. The amount of data from the observations will be huge, and hence efficient data compression will be …

Improved in-cell structure determination of proteins at near-physiological concentration

Investigating three-dimensional (3D) structures of proteins in living cells by in-cell nuclear magnetic resonance (NMR) spectroscopy opens an avenue towards understanding the structural basis of their functions and physical properties under …

Rate-distortion functions for gamma-type sources under absolute-log distortion measure

When the information source is a continuous distribution and the rate-distortion function is strictly larger than the Shannon lower bound, the explicit evaluation of the rate-distortion function is not straightforward. We evaluate the rate-distortion …