小データを用いた機械学習のための情報の探索と活用

京都大学新制・課程博士博士(情報学)甲第23313号情博第749号新制||情||128(附属図書館)京都大学大学院情報学研究科知能情報学専攻(主査)教授 鹿島 久嗣, 教授 山本 章博, 教授 吉川 正俊学位規則第4条第1項該当Doctor of InformaticsKyoto UniversityDFA

Defect imaging for plate-like structures using diffuse acoustic wave generated by modulated laser

Authors have studied defect imaging technique for plate-like structures, which creates an image beyond diffraction limit and can be applied to a plate-like structure with a complex shape because this technique just uses variations of flexural vibration energy due to the differences in nominal bending stiffness at laser spots. However, this technique generates spurious images caused by the resonance as well as defect images. The current study described how the spurious images can be reduced using diffuse acoustic wave, and then showed that images of defects and adhesive regions can be obtained appropriately even in such complex structures as a flat plate with a complex shape, a curved plate, and a branch pipe.45TH ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLUME 38, 15–19 July 2018, Vermont, USATakahiro Hayashi and Shogo Nakao, "Defect imaging for plate-like structures using diffuse acoustic wave generated by modulated laser", AIP Conference Proceedings 2102, 050003 (2019) https://doi.org/10.1063/1.509976

Remote defect imaging for plate-like structures based on the scanning laser source technique

In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe.44TH ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLUME 37, 16–21 July 2017, Provo, Utah, USATakahiro Hayashi, Atsuya Maeda, and Shogo Nakao, "Remote defect imaging for plate-like structures based on the scanning laser source technique", AIP Conference Proceedings 1949, 090006 (2018) https://doi.org/10.1063/1.503156

Exact Solutions of Holonomic Quantum Computation

Holonomic quantum computation is analyzed from geometrical viewpoint. We develop an optimization scheme in which an arbitrary unitary gate is implemented with a small circle in a complex projective space. Exact solutions for the Hadamard, CNOT and 2-qubit discrete Fourier transform gates are explicitly constructed.Comment: 11 pages, re-organized to be more comprehensive, references added, style file of Physics Letters A is neede

Remote defect imaging for plate-like structures based on the scanning laser source technique

In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe

Distribution of Dust around Galaxies: An Analytic Model

We develop an analytic halo model for the distribution of dust around galaxies. The model results are compared with the observed surface dust density profile measured through reddening of background quasars in the Sloan Digital Sky Survey (SDSS) reported by Menard et al.(2010). We assume that the dust distribution around a galaxy is described by a simple power law, similarly to the mass distribution, but with a sharp cut-off at $\alpha R_{\rm vir}$ where $R_{\rm vir}$ is the galaxy's virial radius and $\alpha$ is a model parameter. Our model reproduces the observed dust distribution profile very well over a wide range of radial distance of $10 - 10^{4} h^{-1}$kpc. For the characteristic galaxy halo mass of $2\times 10^{12} h^{-1}M_{\odot}$ estimated for the SDSS galaxies, the best fit model is obtained if $\alpha$ is greater than unity, which suggests that dust is distributed to over a few hundred kilo-parsecs from the galaxies. The observed large-scale dust distribution profile is reproduced if we assume the total amount of dust is equal to that estimated from the integrated stellar evolution over the cosmic time.Comment: 5 pages, 4 figures, corrected typo and minor revisions, results unchanged, MNRAS Letters, in pres