Characteristics of floating gate device as analogue memory for neural networks

An effective controlling circuit for a floating-gate MOSFET analogue memory used in neural networks is described. It is possible to charge or discharge the floating gate storage with high resolution of more than 1% of full scale. The experimental results are described and discussed. An improved device structure is proposed for simplifying the controlling circuit.<>     

Sj?gren's syndrome in the adolescent. Report of four cases

We report three cases of Sj?gren's syndrome and a case with a probable diagnosis of Sj?gren's syndrome at the ages of 16 (2 cases), 17, and 18 years. Two patients were affected by systemic lupus erythematosus. All four patients showed periductal lymphocytic infiltration in the labial glands. Two of the three patients underwent parotid sialography that revealed punctate or globular sialectasis. A decrease in stimulated parotid flow rate was noted in three of the cases compared with age-matched healthy females, whereas only one patient was diagnosed as having keratoconjunctivitis sicca.     

Magnetic instability of ac multifilamentary superconductors in spatially distributed magnetic field

Alternating current (ac) superconducting machines such as superconducting generators, transformers, or resistive current limiters need large‐current‐capacity conductors. These conductors are generally fabricated as multistrand cables stacked with multifilamentary NbTi superconductors whose current capacity is a few tens of amperes. ac quench current degradation has often been observed in ac use of such multistrand cables. Several reasons for this degradation have been pointed out: nonuniformity of each strand current, mechanical disturbances, thermomagnetic instability, and ac losses. However, it has not as yet been overcome. Since the angle between the strand axis and the cable axis changes along the cable axis in multistrand cables, the strands are exposed to a spatially (axially) distributed magnetic field, which has longitudinal and transverse components changing periodically due to multiple cabling. This paper mainly discusses the thermomagnetic instability due to the distributed transverse magnetic field, which was compared with the self‐field instability and the longitudinal field instability experimentally and theoretically. It was confirmed that the ac quench current degradation due to the distributed transverse field could be induced by the following: nonlinear E–j characteristic, strong dependence of E–j characteristic on magnetic field in low field region, uniformity of the axial current profile inside the superconductor with the high resistive matrix, and the poor thermal diffusion of CuNi/NbTi composites. © 2000 Scripta Technica, Electr Eng Jpn, 131(1): 45–55, 2000