A short channel MOS FET with 1-1.5 µm channel and double boron-ion implantation has been designed as a high speed static RAM element. High speed properties and short channel effects are compared among the MOS FETs with 1.5-100 Ωcm substrate and several deep/shallow implant dose combinations. It is found that 40 Ωcm substrate or so with 4/45/310¹¹ cm² deep/shallow implant dose combination is most desirable.

One of the main loss factors in the optical fibers fabricated by the vapor phase axial deposition process is at present residual OH ions which are originated mainly from an oxy-hydrogen flame. Residual OH ions show an influence on loss increase, especially, in the long wavelength region. OH-ion behaviors in the porous perform, transparent perform and drawn fibers are studied with use of an infrared spectroscopy and fiber transmission measurement. In order to realize low OH content VAD fibers, the dehydration effect of halide vapor on the porous perform is investigated experimentally. Dehydration effect of thionyl chloride on the porous perform is studied by various heat treatment temperature. As a result, residual OH ion content in the drawn fiber was reduced from 30 ppm to 20 ppb and the attained minimum loss of dehydrated fiber was 0.5 dB/km and 0.28 dB/km at 1.3 µm and 1.6 µm wavelengths, respectively. Present investigation clarified that the VAD fibers are applicable to an optical transmission system in the long wavelength band. We compare the loss peak values at the wavelengths of 1.39, 1.24 and 0.95 µm among several optical fibers fabricated by different method. Especially, the VAD fibers dehydrated with SOC1₂ show abnormal peak ratios at the wavelengths.

An extraction method of contour lines from a contour map on the market and their restoration method are described. Twin tracing points (clockwise and counterclockwise) are used to trace and extract line components from the map which involves not only contour lines but also block components such as symbols and numerals. To implement the tracing successfully, ending conditions and setting manners of the twin tracing points are dealt with taking various kinds of curves into consideration. By this method, sets of the coordinates of traced contour lines, step numbers of tracing, and moreover, the thickness and length of traced contour lines, the coordinates of their skeleton lines are obtained. Since some contour lines are cut off by the elimination of symbols and numerals, to restore them a finding method of a pair of cut off points which must be connected is also described. For the restoration, an adjacent graph is introduced with an example, and several cases of relations between a graph and set of contour lines are dealt with. A determining algorithm of a pair of connecting candidates is given. Finally, as the results, an original contour map of a mountainous area, extracted contour lines, skeleton contour lines and a connected (by straight lines) contour map obtained through the twin-tracing-points method and restoration method are illustrated.

Any imperfections of a dielectric thin-film waveguide can be mainly classified into the irregular boundary interfaces and the refractive-index fluctuations. In this report we demonstrate a simple method to obtain the scattering losses caused by the two typical imperfections in terms of the coupled power coefficients.

We reveal that the degree of pattern separation in a two-layer random neural net with inhibitory connection has a favorable property for pattern classification. We also consider the effect of the number of connections between the two layers on the above property.