Utsunomiya University

About: Utsunomiya University is a education organization based out in Utsunomiya, Japan. It is known for research contribution in the topics: Laser & Holography. The organization has 4139 authors who have published 6812 publications receiving 91975 citations. The organization is also known as: Utsunomiya daigaku.

Cross-Field Aerial Haptics: Rendering Haptic Feedback in Air with Light and Acoustic Fields

Abstract: We present a new method of rendering aerial haptic images that uses femtosecond-laser light fields and ultrasonic acoustic fields. In conventional research, a single physical quantity has been used to render aerial haptic images. In contrast, our method combines multiple fields (light and acoustic fields) at the same time. While these fields have no direct interference, combining them provides benefits such as multi-resolution haptic images and a synergistic effect on haptic perception. We conducted user studies with laser haptics and ultrasonic haptics separately and tested their superposition. The results showed that the acoustic field affects the tactile perception of the laser haptics. We explored augmented reality/virtual reality (AR/VR) applications such as providing haptic feedback of the combination of these two methods. We believe that the results of this study contribute to the exploration of laser haptic displays and expand the expression of aerial haptic displays based on other principles.

A Polarizer Using Thin Metallic-Film Subwavelength Grating for Infrared to Terahertz Region

Abstract: A polarizer using a sinusoidal or triangular thin metallic-film subwavelength grating is proposed. The dependence of polarizer transmission characteristics on structural parameters of the grating was obtained numerically, and its potential for high performance was confirmed experimentally. The measured transmission loss for the TE-waves with a 25 nm-thick gold-film grating with a triangular profile was higher than 50 dB while the corresponding transmission loss for the TM-waves was lower than 1 dB in the frequency range of 1.0-2.5 THz. The metallic subwavelength grating structure has demonstrated its potential as a low-loss, high-extinction ratio, wide-aperture, and robust polarizer for the infrared and terahertz regions.

Use of balloon aerial photography for classification of kushiro wetland vegetation, northeastern japan

Abstract: Kushiro wetland in northeastern Japan is a Ramsar-designated wetland of international importance (1980) that is characterized by high biodiversity and spatial heterogeneity. These characteristics of the wetland also present innumerable challenges for mapping and monitoring such unique ecosystems. Recent advances in remote sensing technology have provided many sensors with different spatial and spectral scales and resolutions. However, they are still inadequate for mapping wetland vegetation at a large scale for various reasons, such as inadequate resolution and high costs. This study was designed to evaluate the potential of balloon aerial photography to acquire high resolution (15 cm pixel size) imagery for mapping wetland vegetation in the Akanuma marsh. We used a standard 28-mm non-metric camera (Nikon-F-801), which seven specific categories (species mixes) were successfully delineated. It was possible to classify small shrubs mixed with herbaceous plants; moss bogs with pools; dwarf shrubs with sedges; and moss with alpine plants. From this research, it seems that balloon aerial photography is a powerful tool for mapping temperate wetland vegetation, allowing classification of specific and typical vegetation types to the genus and species level.

The barrier component and the driving force component of transepidermal water loss and their application to skin irritant tests

Abstract: Background/aim According to Fick's law of diffusion, the rate of transepidermal water loss (TEWL) is determined by a barrier component and a driving force component. The objective of this study is to propose novel indicators for the assessment of skin irritation potential from chemicals using these components. Methods Before and after acetone/ether (AE), sodium lauryl sulfate (SLS) and nicotinic acid methyl ester (NME) treatments, the apparent mass transfer coefficient of water, K, of the stratum corneum (SC) and the apparent water vapor pressure, P(d), at the interface between SC and epidermis were estimated as measures of the SC barrier and the driving force, respectively. Results After AE treatment, K showed marked increase and P(d) remained approximately constant. All participants reacted to NME with erythema and the laser-Doppler flowmetry (LDF) value peaked at around 30 min. While there was a change in P(d), which parallels with LDF changes, K showed little variation. Repeated SLS treatment induced a slight increase in P(d) besides an increase in K. In the meantime, all participants reacted with subtle erythema. Conclusions Our results suggest that not only the SC barrier but also the driving force determines variations in the TEWL rates during skin irritant tests. Together, K and P(d) will provide us with invaluable information about skin condition.

Structured chaos in a devil's staircase of the Josephson junction

Abstract: The phase dynamics of Josephson junctions (JJs) under external electromagnetic radiation is studied through numerical simulations. Current-voltage characteristics, Lyapunov exponents, and Poincare sections are analyzed in detail. It is found that the subharmonic Shapiro steps at certain parameters are separated by structured chaotic windows. By performing a linear regression on the linear part of the data, a fractal dimension of D = 0.868 is obtained, with an uncertainty of ±0.012. The chaotic regions exhibit scaling similarity, and it is shown that the devil's staircase of the system can form a backbone that unifies and explains the highly correlated and structured chaotic behavior. These features suggest a system possessing multiple complete devil's staircases. The onset of chaos for subharmonic steps occurs through the Feigenbaum period doubling scenario. Universality in the sequence of periodic windows is also demonstrated. Finally, the influence of the radiation and JJ parameters on the structured chaos is investigated, and it is concluded that the structured chaos is a stable formation over a wide range of parameter values.