FreeWalk: a 3D virtual space for casual meetings

A meeting environment for casual communication in a networked community, FreeWalk provides a 3D common area where everyone can meet and talk freely. FreeWalk represents participants as 3D polygon pyramids, on which their live video is mapped. Voice volume remains proportional to the distance between sender and receiver. For evaluation, we compared communications in FreeWalk to a conventional desktop videoconferencing system and a face-to-face meeting     

Thermodynamic calculation of phase equilibria of the Bi-Sn-Zn system

A thermodynamic assessment of the Bi-Sn-Zn ternary system was carried out by considering the experimental data including the phase equilibria and thermodynamic properties on the basis of the CALPHAD method. A set of optimized thermodynamic parameters has been obtained, which leads to a very good fit between calculation and experiments. In particular, the thermodynamic calculations in the Sn-rich portion are presented in view of the recent progress in Pb-free solder alloys.     

Miscibility gap due to ordering in the BCC Fe-Ge system

Phase equilibria in the bcc Fe-Ge system have been investigated by means of electron probe microanalysis and transmission electron microscopy. Two kinds of ordered phases, B2 and DO₃ types, have been detected, the B2 phase being formed from the disordered A2 phase by a 2nd order transition. The DO₃ phase is also formed from the B2 phase by a 2nd or higher order transition at higher temperatures. Below about 820 °C, however, the transition becomes a 1st order, and a miscibility gap between these ordered phases occurs in the composition range from 13 to 16 at. pct Ge. It has been also confirmed that the solubility of Ge in the bec phase shows a retrogression due to the formation of DO₃ phase. On the basis of these experimental results, the phase diagram for the Fe-Ge system has been partly revised.     

Modeling of chloride diffusivity coupled with non-linear binding capacity in sound and cracked concrete

The objective of this research is to establish a model that can predict chloride transport phenomena in sound and cracked concrete. The chloride diffusivity is formulated based on computed micro-pore structure, which considers tortuosity and constrictivity of porous network as reduction factors in terms of complex micro-pore structure and electric interaction of chloride ions and pore wall. In the real environment, concrete structures are not always crack-free, therefore chloride transport in cracked concrete is also simulated by section large void spaces in a control volume to represent the crack and by proposing a model of chloride diffusivity through the cracked region The proposed models are implemented into a finite-element computational program DuCOM, which simulates the early-age development process of cementitious materials. The calculated concentration profiles of total chloride ions are verified through a comparison with experiments results.     

Cooking up an interactive olfactory game display.

It's long been possible to give users outside an actual environment that environment's visual and auditory information and thus contribute to establishing presence. However, we've yet to establish much presence when users require olfactory information - such as in environments focused on foods, flowers, perfumes, or, in some cases, more offensive smells. Recently, several VR researchers have become interested in olfaction and olfactory displays that present smells in virtual environments (VEs). In this article, we describe our interactive olfactory display. One of our development goals is to confirm the assumption that users' interactions with the system increases presence. Thus, we used our interactive olfactory display to develop a cooking game in collaboration with electronic engineers and artists.     

Observation of Magnetic Domain Structures of Magnetic Thin Films by the Lorentz Electron Microscopy

Inthisdecade,agreatmanyresearchworksonmulti-layeredmopeticthinfilmshavebeenreport6d,sincethemagneticmulti-layeredfilmsarethemosthopefulnovelmagneticmaterialsforthenextgenerationelectionicdevises,suchasgialmagneto-resiSbocesensorelemeds.hiordertOdevel...     

Multielectrode DBR laser diode for wide bandwidth and flat FM response

A flat red-shifted FM response over a 1 GHz bandwidth has been achieved in a newly fabricated three-electrode DBR LD. Since the DBR structure makes it possible to tune the wavelength without distorting the FM characteristics, the LD is suitable for transmitters in optical FDM communications using FSK lightwaves.<>     

Simple approximations for chromatic dispersion in single- mode fibers with various index profiles

Simple approximate formulas of chromatic dispersion and zero-chromatic dispersion wavelength are empirically derived for single-mode fibers with various index profiles having the deformations such as a central dip, hump, and/or tailing at a core cladding interface. These profiles are typical which are commonly obtained in current single-mode fibers. The approximation is based on the exact solution of vector-wave equation. These accuracies are better than 0.3 and 0.03 percent for the chromatic dispersion and zero-chromatic dispersion wavelength, respectively. With the aid of the simple approximations, the properties of chromaric dispersion and zero-chromatic dispersion wavelength for practical single-mode fibers are discussed. The relation between the chromatic dispersion and basic fiber parameters of single-mode fibers, effective cutoff wavelength of the LP11mode, and the spot-size of the LP01mode, are clarified.     

A 144-Mb, eight-level NAND flash memory with optimized pulsewidthprogramming

We report a fast-programming, compact sense and latch (SL) circuit to realize an eight-level NAND flash memory. Fast programming is achieved by supplying optimized voltage and pulsewidth to the bit lines, according to the programming data. As a result, all data programming is completed almost simultaneously, and 0.67-MB/s program throughput, which is 1.7 times faster than conventional program throughput, is achieved. The compact layout of the SL circuit is made possible by four 3-bit latches sharing one unit of the read/verify control circuit. Using these techniques, we fabricated a 144-Mb, eight-level NAND flash memory using a 0.35-μm CMOS process, resulting in a 104.2-mm² die size and a 1.05-μm² effective cell size