Design of Neural Networks Based on Wave-Parallel Computing Technique

A Wave-Parallel Computing (WPC) technique is proposed to address the interconnection problem in massively-parallel analog hardware required for implementing neural networks. The fundamental concepts are the frequency multiplexing of signals on a single line, and their wave-parallel processing without decomposition. This paper discusses the realization of a Hopfield-type massively-connected neural network, and shows that the WPC-based network exhibits much lower topological complexity compared with the original network. We also investigate the possible implementation of WPC using the present MOS technology, and discuss the performance evaluation in terms of the degree of multiplexing and the processing speed.     

Phase separation in Ga-doped MgZnO layers grown by plasma-assisted molecular-beam epitaxy

We report on the phase separation of Ga-doped MgZnO layers grown by plasma-assisted molecular-beam epitaxy. Based on X-ray diffraction, low-temperature (10 K) photoluminescence, and reflection high-energy electron diffraction observations, it is possible to classify the phase of Ga-doped MgZnO layers into three regions depending on the incorporated Ga concentration ([Ga]). Single-phase Mg_0.1Zn_0.9O layers are grown when [Ga] is less than 1×10¹⁸ cm⁻³. For [Ga] between 1×10¹⁸ cm⁻³ and 1×10²⁰ cm⁻³, ZnO and Mg_0.2Zn_0.8O coexist, where electron transport is considered to be via two-channel conduction. When [Ga] exceeds 1×10²⁰ cm⁻³, the Ga-doped MgZnO layers become polycrystalline, where carrier compensation takes place presumably due to grain boundaries.     

Study of contact resistance of high-mobility organic transistors through comparisons

Realization of high-frequency low-cost organic electronics requires high-mobility organic field-effect transistors (OFETs) with short channels, where influence of contact resistance becomes more serious than either lower mobility or longer channel devices. To reduce the contact resistance, we systematically and quantitatively investigate the influence of the lowest unoccupied molecular orbital (LUMO) level of an electron acceptor layer, the active layer thickness, and the side chain of active layer itself on contact resistance of top-contact high-mobility OFETs through a series of comparative analysis. We find that the acceptor of 1,3,4,5,7,8-hexafluoro tetracyano naphtha quinodimethane (F₆TNAP) with a deeper LUMO level is efficient for carrier injection and that the bulk resistance plays an important role in such devices. By optimizing the parameters, we get the lowest contact resistance of only 110 Ω cm, and thus recorded effective mobility of 8.0 cm²/V s is attained for polycrystalline thin film transistors and still kept as high as 6 cm²/V s at shorter channel lengths.     

Light‐Driven Delivery and Release of Materials Using Liquid Marbles

Remote control of the locomotion of small objects is a challenge in itself and may also allow for the stimuli control of entire systems. Here, it is described how encapsulated liquids, referred to as liquid marbles, can be moved on a water surface with a simple near‐infrared laser or sunlight. Using light rather than pH or temperature as an external stimulus allows for the control of the position, area, timing, direction, and velocity of delivery. This approach makes it possible to not only transport the materials encapsulated within the liquid marble but also to release them at a specific place and time, as controlled by external stimuli. Furthermore, it is shown that liquid marbles can work as light‐driven towing engines to push or pull objects. Being able to remotely transport and push/pull the small objects by light and control the release of active substances on demand should open up a wide field of conceivable applications.     

Rice as the most influential source of cadmium intake among general Japanese population

The objective of the present study is to examine whether rice is still a leading source of cadmium (Cd) burden among general populations in Japan. For this purpose, 10 prefectures were selected from all over Japan (including the northern- and southern-most Hokkaido and Okinawa prefecture, respectively). Cadmium levels in urine of never-smoking women (corrected for creatinine; Cd-Ucr) were compared with the rice- and wheat product-based Cd intake, which were estimated from Cd contents in rice and wheat (in the forms of bread, noodle and flour) consumed by residents in the areas, and per-capita daily consumption of rice and wheat. Stepwise multiple regression analysis taking Cd-Ucr as a dependent variable and rice- or wheat product-based Cd intakes as independent variables showed that rice was the most influential and almost exclusive variable with a partial correlation coefficient of 0.770-0.832, explaining 59-69% of total variation in Cd-Ucr. The effects of other sources including wheat were essentially negligible.     

EXAFS characterization and selective olefin hydroformylation on Rh4, Rh2Co2 and RhCo3 carbonyl clusters attached to tris-hydroxymethylphosphine-grafted silica

Rh_4-xCo_x(CO)₁₂ (x = 0, 2, 3) are attached by carbonyl substitution to THP (tris-hydroxymethylphospine)-grafted silica keeping their cluster frameworks. They have been characterized by Rh K-edge EXAFS (extended X-ray absorption fine structure) and Fourier transform IR spectroscopy. They exhibited high catalytic activity with > 98% selectivity in gas phase hydroformylation of ethene and propene to give aldehydes under mild conditions (40 kPa and 300–373 K).On leave from Research Center, Arakawa Chemical Industries, LTD, Tsurumi, Osaka 538, Japan.On leave from Department of Chemistry, National University of Literal, Santiago del Estero, 2829-3000, Santa Fe, Argentina.     

Conduction paths in sintered ionic conductive material Na1+xYxZr2−x(PO4)3

A NASICON type ionic conductor was synthesized. The ionic conduction paths for its ceramics were examined and interpreted by a simple equivalent circuit. It is recognized that two kinds of grain boundaries exist, which play as blocking element and high diffusive path, respectively. The grain boundaries in this ceramics dominate the total conductivity.     

Seismic isolation rubber bearings for nuclear facilities

This paper describes results of biaxial breaking tests by compression and shear and by tension and shear for seismic isolation rubber bearings with bolted-type connections. The bearings used in the tests were low-damping rubber bearings, high-damping rubber bearings, and lead-rubber bearings. Three modes of failure of the bolted-type bearings were observed in the tests. They are the breaking failure by tension and shear; the breaking failure by compression and shear; and the buckling failure by compression and shear. The first and the second modes of failures are almost independent of the types and the sizes of the bearings. The breaking conditions of those failure modes are described in the axial-stress-shear-strain plane. This expression is useful for the evaluation of safety margins of the bearings.The paper outlines the basic design of the nuclear-grade bearings which were used for large-scale rubber bearing tests in a research project for seismic isolation of fast breeder reactor (FBR) plants. The paper also discusses the protection method against aging and the quality control which are important for implementation.     

Wireless Monitoring Using a Stretchable and Transparent Sensor Sheet Containing Metal Nanowires

Mechanically and visually imperceptible sensor sheets integrated with lightweight wireless loggers are employed in ultimate flexible hybrid electronics (FHE) to reduce vital stress/nervousness and monitor natural biosignal responses. The key technologies and applications for conceptual sensor system fabrication are reported, as exemplified by the use of a stretchable sensor sheet completely conforming to an individual's body surface to realize a low-noise wireless monitoring system (<1 µV) that can be attached to the human forehead for recording electroencephalograms. The above system can discriminate between Alzheimer's disease and the healthy state, thus offering a rapid in-home brain diagnosis possibility. Moreover, the introduction of metal nanowires to improve the transparency of the biocompatible sensor sheet allows one to wirelessly acquire electrocorticograms of nonhuman primates and simultaneously offers optogenetic stimulation such as toward-the-brain–machine interface under free movement. Also discussed are effective methods of improving electrical reliability, biocompatibility, miniaturization, etc., for metal nanowire based tracks and exploring the use of an organic amplifier as an important component to realize a flexible active probe with a high signal-to-noise ratio. Overall, ultimate FHE technologies are demonstrated to achieve efficient closed-loop systems for healthcare management, medical diagnostics, and preclinical studies in neuroscience and neuroengineering.