Publications by authors named "Hsin-Yu Yao"

We develop a theory of refractive index tuning for symmetry-protected optical bound states (SP-BICs) in high-contrast gratings (HCGs). A compact analytical formula for tuning sensitivity is derived and verified numerically. We also discover a new type of SP-BIC in HCGs that has an accidental nature with a spectral singularity, which is explained in terms of hybridization and strong coupling among the odd- and even-symmetric waveguide-array modes.

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This work develops a nonlinear and self-consistent framework for the single-mode simulation of TM-mode gyrotrons. Unlike TE modes, a nonlinear TM wave equation is derived by considering the additional axial modulation on the electron beam due to the interaction with the axial electric field. Together with the electrons' equations of motion, particle tracing simulation is conducted to model TM-mode oscillation.

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This study aimed to characterize the changes in the visual field (VF) patterns and disc morphology of patients with thyroid-associated orbitopathy (TAO) and open-angle glaucoma (OAG). A retrospective review of the medical records at the Tri-Service General Hospital in Taiwan identified 396 eyes of 198 patients with thyroid-associated glaucoma. A final follow-up of VF examination in 140 eyes revealed 114 eyes with VF defects, indicating disease progression.

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We synthesized BaTiO-epoxy nanocomposites (particle size < 100 nm) with volume fractions up to 25 vol. %, whose high-frequency complex permittivity was characterized from 8.2 to 12.

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We develop a theory for Fano resonance tuning in dual-mode high-contrast gratings (HCGs). Compact analytical formulas of tuning sensitivity are derived and verified numerically, and are in good agreement with reported experiments. We show that the resonance tuning in HCGs, containing cooperative contribution from two propagating modes, is fundamentally different from that in single-mode microresonators.

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We propose a compact nearfield scheme for fast and broadband dielectric characterization in the microwave region. An open-type circular probe operated in the high-purity TE mode was developed, showing a strongly confined fringing field at the open end. This fringing field directly probed the freestanding sheet sample, and the overall reflection was measured.

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A methodology that applies hyperspectral imaging (HSI) on ophthalmoscope images to identify diabetic retinopathy (DR) stage is demonstrated. First, an algorithm for HSI image analysis is applied to the average reflectance spectra of simulated arteries and veins in ophthalmoscope images. Second, the average simulated spectra are categorized by using a principal component analysis (PCA) score plot.

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Ultrashort bunches of electrons, emitted from solid surfaces through excitation by ultrashort laser pulses, are an essential ingredient in advanced X-ray sources, and ultrafast electron diffraction and spectroscopy. Multiphoton photoemission using a noble metal as the photocathode material is typically used but more brightness is desired. Artificially structured metal photocathodes have been shown to enhance optical absorption via surface plasmon resonance but such an approach severely reduces the damage threshold in addition to requiring state-of-the-art facilities for photocathode fabrication.

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A 20-year-old male soldier was hit by the jellyfish. The ophthalmic examination revealed that epithelial keratitis and corneal oedema in the right eye. We prescribed 3% NaCl eyedrops and 0.

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This study investigated the relationships among intraocular pressure (IOP), nitric oxide (NO) levels, and aqueous flow rates in experimental ocular hypertension models. A total of 75 rabbits were used. One of four different materials [i.

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