Takefumi Hayashi

Dynamic Characteristics of Gas-Lubricated Slider Bearings Under High Knudsen Number Conditions

This paper presents numerical analyses of the dynamic characteristics of gas-lubricated slider bearings under high Knudsen number conditions using a generalized lubrication equation based on the Boltzmann equation. The present analysis is applied to the dynamic response of flying head sliders for magnetic disk storage devices. For a small slider with ultra-thin spacing, the deviations of the slip flow approximation equations are remarkable in regard to steady flying characteristics, but insignificant in regard to dynamic characteristics

Effects of visual-field inversions on the reverse-perspective illusion.

The ‘reverse-perspective’ illusion entails the apparent motion of a stationary scene painted in relief and containing misleading depth cues. We have found that, using prism goggles to induce horizontal or vertical visual-field reversals, the illusory motion is greatly reduced or eliminated in the direction for which the goggles reverse the visual field. We argue that the illusion is a consequence of the observers inability to reconcile changes in visual information due to body movement with implicit knowledge concerning anticipated changes. As such, the reverse-perspective illusion may prove to be useful in the study of the integration of linear perspective and motion parallax information.

Effects of Moving Three-Dimensional Nano-Textured Disk Surfaces on Thin Film Gas Lubrication Characteristics for Flying Head Slider Bearings in Magnetic Disk Storage

This paper describes the effects of moving three-dimensional nano-textured or patterned disk surfaces on thin film gas lubrication characteristics for flying head slider bearings in magnetic disk storage, In order to perform the most realistic simulation of slider flying characteristics over the textured disk surfaces, the direct numerical simulation method is used, instead of using various averaging techniques. Therefore, a deterministic description of the texture is adopted in this study. A dynamic analysis of the slider responses can be carried out, by solving the air bearing equation based on the linearized Boltzmann equation with the equations of motion of the slider under the excitation of the moving texture simultaneously. The sliders dynamic responses to moving spaced bumps disk surfaces, including both the circumferentially and radially ridged disk surfaces, are computed systematically and basic slider dynamics over patterned disk surfaces is investigated, The effects of the texture area ratios (= texture width/texture pitch) in the circumferential and radial directions on the slider spacing dynamic modulations as well as the slider static flying characteristics are also studied. Furthermore, the effects of three kinds of texture patterns on the slider flying characteristics are investigated. Considering those simulation results, the design optimization for the texture pattern that minimizes not only the slider static flying height increase but also spacing dynamic modulations is discussed in order to achieve ultra-high density proximity magnetic recording.

Lattice models for quark, nuclear structure and nuclear reaction studies

Because of their computational simplicity, lattice models have found various uses in quark, nuclear structure and nuclear reaction (multifragmentation and heavy-ion) studies. However, differences in the mean density of particles among crystal types lead to significantly different properties, indicating that simulations using nucleon lattices should compare several lattice structures. The characteristics of five important lattice groups are discussed and fundamental algorithms are provided.

Modeling the cognitive map formation process based on psychological experiments using a computer graphics system

Four psychological experiments using a computer graphics system were conducted to investigate human spatial recognition performance. It was found that the exponent of the power function for remembered distance decreases as the memory load increases. This exponent decrease was predicted by a psychological model based on signal detection theory. In addition, the spatial recognition process while navigating in a complicated space was examined and the capacity of the spatial memory clarified.<<ETX>>

A Compact Multi-Layered Wideband Bandpass Filter Exhibiting Left-Handed and Right-Handed Behaviors

This letter proposes a compact multi-layered bandpass filter exhibiting left-handed and right-handed behaviors in its passband. This filter has a greatly expanded passband from 1.61 GHz to 4.16 GHz (88.4% bandwidth) with a maximum ripple of 1.2 dB and well-suppressed out-of-passbands with transmission zeros at 1.15 GHz and 4.52 GHz. The physical mechanisms are studied with FEM-based full-wave simulations, equivalent circuit analysis and careful experiments.

Development of cultural capital content using ultra-high resolution images

classroom use is granted without fee provided that copies are not made or distributed for commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the Owner/Author. SIGGRAPH 2014, August 10 – 14, 2014, Vancouver, British Columbia, Canada. 2014 Copyright held by the Owner/Author. ACM 978-1-4503-2958-3/14/08 Development of Cultural Capital Content using Ultra-High Resolution Images

Visualization of the growth process of pruned and trained citrus trees for appropriate cultivation

Citrus plants have a long history in human societies, during which various cultivation techniques have been devised to increase yields and are still being developed. King Mandarin, one of the most important citrus cultivars in southern Vietnam, is not an exception. The Southern Horticultural Research Institute, formerly the Southern Fruit Research Institute, of Vietnam (SOFRI) has been working on this issue for many years, but these techniques have rarely been utilized in southern Vietnam, and their value is not widely acknowledged either by growers or by officers of this area. The present research is an attempt to visualize the growth process of the King Mandarin trees which are treated with the appropriate cultivation technique and also to develop an interactive system for rapid extension and wide acceptance of the technique in southern Vietnam.

An Investigation of Surface Reconstruction from Binocular Disparity Based on Standard Regularization Theory: Comparison between “Membrane” and “Thin-Plate” Potential Energy Models

Visible surfaces of three-dimensional objects are reconstructed from two-dimensional retinal images in the early stages of human visual processing. In the computational model of surface reconstruction based on the standard regularization theory, an energy function is minimized. Two types of model have been proposed, called “membrane” and “thin-plate” after their function formulas, in which the first or the second derivative of depth information is used. In this study, the threshold of surface reconstruction from binocular disparity was investigated using a sparse random dot stereogram, and the predictive accuracy of these models was evaluated. It was found that the thin-plate model reconstructed surfaces more accurately than the membrane model and showed good agreement with experimental results. The likelihood that these models imitate human processing of visual information is discussed in terms of the size of receptive fields in the visual pathways of the human cortex.

fMRI study of the aesthetic emotions (“kansei”): Pictorial depth perception and musical harmony

Hydrogen sulfide (H2S) is a signaling molecule as well as a cytoprotectant in the brain. We have shown that H2S protects neurons from oxidative stress by increasing the levels of glutathione (GSH), a major cellular antioxidant. Here we show that H2S enhances the transport of cysteine to increase GSH production more than cystine transport and to redistribute the localization of GSH to mitochondria. The efficiency of GSH production enhanced by H2S is even greater under oxidative stress by glutamate. H2S reinstated GSH levels in the fetal brain decreased by ischemia/reperfusion in utero. In addition, H2S produced by 3-mercaptopyruvate sulfurtransferase (3MST), along with cysteine aminotransferase (CAT) in mitochondria suppresses oxidative stress in this organelle. Neuro2a cells expressing 3MST along with CAT, showed significant resistance to oxidative stress. The present study shows that H2S protects cells from oxidative stress by two mechanisms. It enhances the production of GSH by enhancing cystine/cysteine transporters. H2S produced in mitochondria also may directly suppress oxidative stress. It provides a new mechanism of neuroprotection from oxidative stress by H2S. Research fund: KAKENHI22590258.