A self-learning digital neural network using wafer-scale LSI

A large-scale, dual-network architecture using wafer-scale integration (WSI) technology is proposed. By using 0.8 μm CMOS technology, up to 144 self-learning digital neurons were integrated on each of eight 5 in silicon wafers. Neural functions and the back-propagation (BP) algorithm were mapped to digital circuits. The complete hardware system packaged more than 1000 neurons within a 30 cm cube. The dual-network architecture allowed high-speed learning at more than 2 gigaconnections updated per second (GCUPS). The high fault tolerance of the neural network and proposed defect-handling techniques overcame the yield problem of WSI. This hardware can be connected to a host workstation and used to simulating a wide range of artificial neural networks. Signature verification and stock price prediction have already been demonstrated with this hardware     

Theoretical calculation of fundamental uncertainty region based on the maximum and/or the minimum size in the preparation of standard reference particles for particle size measurement

In order to confirm the reliability of particle size measurement technique and to prepare standard reference particles for calibrating particle size measurement devices, experimental and theoretical studies have been conducted through particle size measurement of silica particles having a size range of 0.1–1 μm.A new theoretical equation to calculate fundamental uncertainty region in the case that the maximum and/or the minimum particle size is known, is derived based on a log-normal distribution truncated by the maximum and/or the minimum. Fundamental uncertainty regions calculated based on these truncated size distributions are compared with that calculated based on the perfect log-normal distribution. The relationship between the parameter u to determine the reliability of size distribution and the truncate-parameter g is obtained to get 95% reliability of the measurement. Value of the parameter u is fairly reduced as the truncate-parameter g becomes smaller.Numerical simulation of uncertainty region agreed with the results calculated by the new theoretical equation. Calculations on the silica particles having a size range of 0.1–1 μm have been conducted showing that the uncertainty region based on the known maximum size is slightly smaller compared to that given in the previous paper.     

Development of a simple and practical method for estimating the liquid absorption of pharmaceutical porous materials using a capillary rise technique

Porous materials are attractive substances for designing pharmaceutical particulates. However, understanding the behavior of liquid absorption into the intra-pores and interstices of porous carrier particles is important to effectively manufacture active pharmaceutical ingredients (APIs) using these carriers. In this study, we established a simple and practical method for evaluating the liquid absorption behavior of porous carriers using force tensiometry and a capillary rise technique. Different-sized tablets of porous materials were prepared and evaluated by this method using various solvents to estimate liquid absorption into the intra-particle pores and interstices of the particles. The amount of liquid trapped in the interstices of the particles decreased with decreasing tablet volume, after which the amount of liquid in the intra-particle pores could be estimated. Finally, API-loaded particles were prepared by absorbing the API solution into porous carriers based on the intra-capacity revealed above. No free API was found on the surface of the prepared particles, as it was well absorbed into the intra-particle pores. Collectively, this tensiometer method using different-sized tablets of porous materials appears to be a promising technique for evaluating the liquid absorption characteristics of porous pharmaceutical materials.     

Effect of initial pH on formation of hollow calcium carbonate particles by continuous CO2 gas bubbling into CaCl2 aqueous solution

Hollow calcium carbonate (CaCO₃) particles are synthesized by continuous bubbling CO₂ gas into CaCl₂ aqueous solution. In order to study the formation kinetics of the hollow CaCO₃ particles, the transmitted light strength of the CaCl₂ solution during the reaction was measured automatically with an on-line monitoring. It was verified that the pH for the formation of the hollow particles depended on the reaction temperature. Higher initial pH of the CaCl₂ solution resulted in the higher ratio of hollow particles as compared to that obtained at lower pH.     

Dye Adsorption Characteristics of Anatase TiO2 Film Prepared in an Aqueous Solution

Anatase TiO₂ film was deposited on SnO₂: F substrate in aqueous solution. The film had an assembly of acicular TiO₂ nanocrystals on the surface. The crystals grew along the c-axis, i.e. perpendicular to the substrate. Dye adsorption increased with film thickness. Intensity of photoluminescence originating from the dye adsorbed on the nanostructured film after annealing was 3 times higher than that of thicker particulate film constructed of TiO₂ nanoparticles (P25). Additionally, dye adsorption property of the film without annealing was two times higher than the film with annealing. Consequently, the as-deposited film had high dye adsorption property which is about 6 times higher that that of thicker particulate film constructed of TiO₂ nanoparticles (P25). Assemblies of acicular crystals on the surface increased the surface area and amount of dye adsorption. The film may be useful for biomolecule sensors and dye-sensitized solar cells.     

Preparation of a platinum electrocatalyst by coaxial pulse arc plasma deposition

We have developed a new method of preparing Pt electrocatalysts through a dry process. By coaxial pulse arc plasma deposition (CAPD), highly ionized metal plasma can be generated from a target rod without any discharged gases, and Pt nanoparticles can be deposited on a carbon support. The small-sized Pt nanoparticles are distributed over the entire carbon surface. From transmission electron microscopy (TEM), the average size of the deposited Pt nanoparticles is estimated to be 2.5 nm, and their size distribution is narrow. Our electrocatalyst shows considerably improved catalytic activity and stability toward methanol oxidation reaction (MOR) compared with commercially available Pt catalysts such as Pt black and Pt/carbon (PtC). Inspired by its very high efficiency toward MOR, we also measured the catalytic performance for oxygen reduction reaction (ORR). Our PtC catalyst shows a better performance with half-wave potential of 0.87 V, which is higher than those of commercially available Pt catalysts. The higher performance is also supported by a right-shifted onset potential. Our preparation is simple and could be applied to other metallic nanocrystals as a novel platform in catalysis, fuel cells and biosensors.     

Self-alignment with optical microconnectors for free-space optical interconnections

A self-alignment technique that uses optical microconnectors forthree-dimensional optics in optical computing systems and opticalinterconnections is proposed. The optical microconnector consistsof an optical plug and a socket. On the output plane of an opticalsystem, optical plugs are made of a photosensitive resin exposed tolight through the optical system. Because the correspondingpositions of the optical plugs are critical to the image formed by theoptical system, a detecting device can be aligned and mounted by theconnection of the optical plugs to sockets formed on the surface of thedevice. Optical microconnectors were experimentally fabricated in areflective block optical system. An alignment accuracy of ~20 mum was attained in the experiment.     

"CT angiogram sign" in obstructive pneumonitis and pneumonia

Malrotation is a rare aetiological factor of intestinal occlusion in adult. We report our experience of 16 cases collected from 1976 to 1991. The incidence is about 0.2-0.5% with two peaks, at 25 and 55 years respectively. Mean age is of 41 years. The symptoms were occlusion in more than 90%. A contrast enema was performed in acute as well as in chronic situations. The surgical treatment whatever it is, is the treatment of choice but has to be put in balance with age.     

Use of ultrasonography in the bladder neck suspension

From 1988 to 1992, 78 patients with genuine stress urinary incontinence underwent bladder neck suspension under ultrasonic monitoring. Tightness of suspension was adjusted by setting posterior urethrovesical angle to approximately 90 degree by transrectal ultrasonography during operation. Urinary continence was achieved in 68 of 78 patients. In the remaining 10 patients, slight incontinence recurred within 6 months after operation. In 60 patients undergoing postoperative chain cystourethrogram, the posterior urethrovesical angles set during operation were about the same as those after operation. In 39 patients undergoing uroflowmetry under the condition that micturition volume was 200 ml or more, urinary flow rate did not decrease after operation. In 20 patients whose posterior urethrovesical angles were measured by transperineal and transabdominal as well as transrectal ultrasonography, angles measured by each ultrasonography were almost identical and neither manipulation could change the configuration of the bladder neck. The posterior urethrovesical angles set during operation were kept postoperatively and provided proper tightness of the suspension suture to achieve urinary continence without any difficulty of urination. Therefore, a posterior urethrovesical angle can be set by transperineal and transabdominal ultrasonography as well as transrectal ultrasonography. While transrectal approach provides the clearest image among the three approaches, transperineal and transabdominal approach carried out with a transabdominal convex or sectorial probe are more convenient than transrectal approach which needed a special probe.