A new type of Josephson NDRO memory cell is presented, where a sense gate is coupled directly to the memory part, instead of the conventional magnetic coupling scheme. The memory cell operates without complexity of the sequence of signals, and the operation margin is shown to be 20%.

An improved algorithm of autocorrelation pitch detection is presented. Preliminary experiments show that the algorithm can considerably reduce the errors caused by the ordinary autocorrelation pitch detector.

A method is proposed to design synchronous mod N counters (logical type) by using many-valued JK flip-flops. Then costs of the counters are derived.

A cylindrical PZT around which some length of a fiber is wound is demonstrated as a component of optical phase shifter and modulator in a single-mode fiber interferometer. Its sensitivity under the operation of DC input mode is 0.18 π rad/V/meter in phase change at the optical wavelength of 6328 . Some characteristics of amplitude response linearity and frequency response uniformity for the AC drive voltage applied to the PZT cylinder are also discussed.

A mirror-type optical switch using a z-cut lithium niobate crystal (LiNbO3) was fabricated, and a two-by-two transverse type optical switch of the Michelson interferometer with two mirror type LiNbO3 crystals and two Wollaston prisms (WP's) was constructed. An optical filter, and a one-by-four optical switch using a combination of an acoustooptic tunable filter (AOTF) employing a Tellurium oxide crystal (TeO2) and this mirror-type LiNbO3 crystal are proposed for applications.

We present a transformation method for reducing the number of states of bypassed Knuth LR(k) parsers. Bypassed Knuth LR(k) parsers behave like Knuth LR(k) parsers except that they perform syntactic analysis without reducing productions of the form X::Y (X and Y are grammar symbols) that have empty semantic actions. Using a characterization of correct bypassed LR(k) parsing obtained by parsing contexts approach of this paper, we show that the transformation of merging of states having same core preserves the validity of the parsers provided that the parsers are free from parsing action conflicts. (Note that in general this property cannot be guaranteed in other type of Bypassed LR(k) parsers than Bypassed Knuth LR(k) parsers.) Using this transformation we can construct a faster LR(k) parser having reasonable number of states. This result is a significant reduction in the size of bypassed LR(k) parsers.

A planar-circuit-type 3 dB hybrid consisting of a four-port disk-shaped resonator is reinvestigated. A great improvement in the characteristics is obtained by rearranging the four ports upon consideration of the higher order resonator modes without loss in simplicity of the structure.

Store-and-forward communication networks with no effective means of flow control are subject to congestion under heavy load conditions. In this paper a distributed congestion control policy, called PF-C, with nodal buffer management strategy based on traffic priorities is proposed and analyzed. The priority of a packet is depended upon the number of hops it has traveled and the number ob hops it has to travel to reach its destination. More importantly, packets are identified into classes according to their priorities. The limited number of buffers (limit value) at any node to be occupied by each class of packets are assigned. The mechanism of this policy is that, a packet which arrived at a given node is rejected if the total number of allocated buffers exceeds a limit value corresponding to its class. Rejected packets are dropped from the network and considered as lost. This policy is analyzed in the context of symmetrical networks, whereby a queuing model is developed. Finally, network throughput which is an example of system performance, is formulated in terms of offered load, total number of buffers in a node and the limit values. Numerical applications to loop networks clearly demonstrate the good behavior of this policy to achieve the maximum network throughput.

In this paper we give an algorithm of automatic theorem proving for various modal predicate systems, and prove its completeness. These modal systems can be tanslated into two-sorted extensional system. Using this fact, the theorem proving can be implemented by using the resolution for the extensional systems. Especially our new results in this paper are two inference rules for S4-modal system, which give a shorter proof than the ordinary resolution.

This paper deals with radiation from and surface wave excitation by a semi-infinite parallel-plate waveguide with an extended dielectric slab which has step discontinuity in permittivity inside the waveguide region. Use is made of the Wiener-Hopf technique in order to investigate precisely the scattering at the parallel-plate waveguide edges as well as at the discontinuity of the dielectric slab. A formal solution is derived by conventional factorization, method, and an iterative method which is effective to this type of formal solution is proposed to calculate the reflection coefficients of waveguide modes, transmission coefficients of excited surface wave modes, and radiation power numerically.

An application of composition graded Gd-Fe amorphous films to a magnetic sensor was studied. The composition graded Gd-Fe amorphous films were prepared by means of a coevaporation technique. The Gd-Fe films were evaporated on the Sio films which were deposited previously on glass substrates, then the Gd-Fe films were overlaid with SiO films. The ferromagnetic domain patterns on the films were examined by means of polar Kerr effect. A magnetic sensor measuring the magnetic fields near the surfaces of specimens was designed using the Gd-Fe film. The magnetic field was determined by measuring the area in which magnetization was inverted by the field. It was demonstrated that the magnetic sensor consist of the Gb-Fe film measured the normal magnetic fields near the specimen less that 1 µm from the surface in the range of 50 to 500 Oe.

A vectorial finite-element method for the analysis of three-dimensional dielectric waveguides is developed in terms of all three components (Hx, Hy, and Hz) of the magnetic field H. In this approach, the divergence relation for H is satisfied and the spurious, nonphysical modes which are included in the solutions of the earlier vectorial finite-element methods do not appear. In order to verify the accuracy of the method, the numerical results for a rectangular waveguide half-filled with dielectric are presented and compared with the exact results. The dielectric rectangular waveguides are also analyzed.

A path-averaged raindrop size distribution is inferred from the equi-probability values of cumulative distribution of rain attenuation measured at 11.5, 34.5, and 81.8 GHz on the same propagation path of 1.3 km in a suburb of Tokyo for three years. By using the size distribution, attenuation coefficients due to rain are obtained in the frequency range from 10 to 300 GHz. The same kind of examination has already been made on the basis of the first one-year data. However, the result obtained this time is slightly stable in comparison with the result for the one-year data in statistical meaning, and is usable for predicting the rain attenuation at frequencies up to about 100 GHz with high accuracy. Moreover, the raindrop size distribution of Laws and Parsons is found to lead to an underestimation of rain attenuation by 30 or 40 percent in dB value at rain rate of 10 to 50 mm/h in the frequency range above about 100 GHz.

An automated measurement system has been developed for measuring a magnetic-field strength inside and outside a motor vehicle exposed to an electromagnetic-field (EM-field). This measurement system consists of an EM-field generator unit, a magnetic-field probe, a data transmission unit with a fiber optic link, a graphic computer and its peripherals. The system is capable of measuring an EM-field strength of 4085 dBµA/m within a frequency range of 20200 MHz, with a certainty of 0.5 dB. The time required for the measurement is approximately three minutes per axis of X, Y or Z at one measuring point when the measurement is repeated five times per specific frequency at 2 MHz intervals for a frequency range of 20200 MHz. This measuring time is one-twentieth as long as that required by conventional unautomated measurement sets.

It has been experimentally found that in a single-choke circular waveguide antenna, the beam circularity and cross-polar properties are greatly affected by the choke position. By properly choosing the choke position, better beam circularity and cross-polar properties can be obtained.

A new parallel merge algorithm suitable for VLSI implementation is proposed. This algorithm can merge a given set of sorted sequences in O (N) computation time, where N is a total number of keys in input sequences, and it works on a linear array of simple identical processors.

We present a simple approximation algorithm for a problem of partitioning a polygonal region into a minimum number of triangles. The objective is to show that the absolute performance ratio of the algorithm is bounded by some constant for any polygonal region.

A computer aided local estimation of fusion splice loss for graded-index optical fibers is proposed. Spliced fiber outer diameter deformation is extracted by image processing technique. The relation between deformation at the splice portion and splice loss is obtained experimentally. It is possible to eliminate large loss splices automatically using the splice portion appearance.

In this paper, the synthesis method of incompletely specified function based on NOR-type polypheck is presented. In synthesizing a function, the size of term is applied. The expanded simplification method in binary logic system is also applied.

Methods for forming a null by only phase control based on search algorithm require complex calculations. This paper presents a method based on beam superposition without search algorithm. Due to this method, optimum phase are obtained directly by simple calculations. To confirm the usefulness of this method, experiments carried out by using circular-arc antennas have been done. Results of experiments show that a deep null can be formed at desired directions.