Fourier-like transforms over the Galois field, GF(q2), and the direct sum of such Galois fields, analogous to the field of complex numbers, were developed and used to design round-off noise free nonrecursive filters (1), (2). It was shown (3), (4) that recursive realizations of finite impulse response (FIR) filters on the finite field or ring are also possible by techniques, analogous to those recursive realizations used on the usual complex number field. This paper developes an algorithm to reduce the number of recursive equations needed to realize a filter when recursive equations are restricted to be first order. The recursive filters developed here do not have the accumulation of round-off or truncation error one usually expects in recursive computations. The FIR filter without error is more naturally a digital" filter than the usual FIR digital filter. By the very finiteness of the finite field or ring, only finite bit words are needed to realize the FIR filter. Such digital filters when realized as discrete transducers are information lossless in the sense of Shannon (5, pp. 26).

The spontaneous emission factor in the rate equation of the injection laser is derived with help of the classical electromagnetic theory. The spontaneous emission is treated as the radiations from dipoles located in the active region. The value of the spontaneous emission factor given theoretically is in good agreement with the measured results. The magnitude of the spontaneous emission factor is inversely proportional to the volume of the active region and the spectral width of the spontaneous emission, and is proportional to the energy confinement factor and the fourth power of the wavelength. The possibility of the suppression of the relaxation oscillation by reducing the volume of the active region is predicted theoretically.

This article gives the realization of two different types of floating inductance with active transformer used in Jaumann type all-pass networks, and some examples of its applications concerning Biquad all-pass networks.

Diode phase shifters are analytically and numerically studied in order to reduce to reduce DC power requirement, and to improve their performances. The residual series resistance of PIN diodes fabricated by the state-of-the-art silicon technology, is analized for the phase shifter use in terms of the punch-through voltage, the junction capacitance, and the forward bias current. Proper diode design for low DC power requirement is found to design the punch-through voltage of 10V which decreases the necessary forward bias current down to 10 mA per diode. The diode is applied to the examination on loss performance of the loaded line and the hybrid coupled phase shifter, where some analysis is made to indicate what diode is suitable for the phase shifter, and what relation there is between the diode impedance and the insertion loss of phase shifters. According to the analysis, and X-band MIC 4-bit 360phase shifter is constructed with an alumina ceramic substrate metallized with Au-Cr through photoresist techniques. This phase shifter requires only 0.81 W max. DC power, but it has the insertion loss of only 2.0 dB in the frequency range between 9.09.5 GHz. In the band, the VSWR performance is less than 1.5, and the phase errors are within5. It is shown that the reduced DC power phase shifter has the equivalent performances as well as the conventional one, except for the handling power capability.

Advanced laser beam scanning pattern, termed the Lattice scan mode", for the fixed scanner in the supermarket Point-of-Sale (POS) system has been developed. This scan mode shows high performance for reading the Universal Product Code (UPC) labels.

This paper deals with a problem of maximizing directivity of a uniformly spaced broadside array under constraints on the specified sidelobe level. For this purpose, we use a quadratic programming in order to clarify the properties of the radiation pattern with high directivity and low sidelobe level. In resulting radiation patterns, the first sidelobes are suppressed to the specified level and other sidelobes decrease gradually in magnitude similarly to a Taylor pattern. The number of sidelobes in equal magnitude is determined by the specified sidelobe level. These properties are still held for both isotropic and parallel dipole elements.

The proportional relationship between the adaptive array under directional constraint and the adaptive array under least-mean-square-error criterion is proved for narrow-banded signal under the condition that the incident direction of the desired signal is identical with the constraint direction.

The phenomena of the wave propagation in a nonlinear transmission line are analyzed theoretically by the derivative expansion method. Each section of this line is constructed with a series inductor L1 and the shunt circuit consisting of a seriesed L2 - C2 element and a nonlinear capacitor C (V) in which V is a line voltage. There exist two modes; L.F. mode propagating in the frequency range 0ωωt and H.F. mode in the range ωpω, where (L2 C2)1 and (1C2/C(0)). In the strongly dispersive region the asymptotic behavior of the nonlinear waves is described by the nonlinear Schrödinger equation and by the Korteweg-de Vries equation in the weakly dispersive region. Critical frequencies ω10 and ω20 (ωpω20ω10) decompose the H.F. mode into three regions (1) ωpωω20, (2) ω20ωω10 and (3) ω10ω. The resonant interaction between the L.F. mode and the H.F. mode occurs in the frequency ω10, while the lowest order nonlinear interaction disappears in the frequency ω20. In the regions (1), (3) and the L.F. mode the plane wave is stable under the wave modulation, while the plane wave is unstable in the region (2). We derive the basic equations describing the three wave interactions and find that the plane wave with a large amplitude becomes unstable through the parametric decay instability. The wave number and maximum growth rate of the excited waves are determined.

A new type of 1:1 optical branch for optical fiber with low insertion loss was fabricated using three graded-index rods. Two pieces of the graded-index rods were cut in parallel to their own optical axes and cemented together with the cut surfaces, and then the third rod is butt-joined to the combined rods. The experimental results were that the insertion loss was 1.1 dB and the distribution ratio was 1:0.98 at 6328 wavelength. Minor modification of this structure enables us to get distribution rations other than 1:1.

In order to evaluate the speaker-factor in uttered words, multivariate analysis of variance for four-factor design with repeated measurements has been applied to the analysis of the spectral vectors obtained from Japanese V1 CV2 utterances by 10 adult male speakers, where V1, V2/a, i, u, e, o/ and Cm, n, η/. The speaker, the vowel V1, the consonant C, and the vowel V2 have been assigned to the four factors, respectively, and the interaction between speaker-factor and V1, C or V2-factor has been especially interesting in the analysis. As the results, what we should take into account as to the co-articulation of a certain phoneme are (1) the main effect of the phoneme, (2) the main effect of the just preceding (or following) phoneme, (3) the interaction between the phoneme and the just preceding (or following) phoneme, and (4) the main effect of the speaker-factor. The interactions between the speaker-factor and these phonemes are relatively small, and the influence of the speaker-factor to the co-articulation is not so complicated. These facts imply possibility of the speaker-independent description about the phoneme and the rule of co-articulation.

A large class of signals can be conveniently modeled by a stationary first-order Markoff process. This paper shows that for such a process the elements of the covariance matrix in the discrete Fourier transform domain can be calculated in closed form which facilitates a direct comparison of the transform with the discrete Karhunen-Loéve transform of KLT. A similar technique is applied to the analysis of the discrete consine transform or DCT. Both transforms are shown to be asymptotically equivalent to the KLT, i.e., they become equivalent to it as the block size or the number of sample points approaches infinity. Significant conclusions in this paper are that in the DCT domain the residual correlation is surprisingly smaller than in the DFT domain even for a nominal block size and that the decorrelation by the DCT is relatively immune to statistics change.

This paper presents a method of extraction of the requested information from English sentences which express a certain fact or relations. The restricted input-English sentences are deterministically reduced using the context-free-type production rules presented here, which is constructed tentatively by introducing nonterminal symbol with subscript-variables. And the corresponding logical expressions are constructed. Extractions of requested informations are efficiently performed using the transformation rules between atomic and functional expressions.

An optimum condition in diffusion-exchange and heat-treatment process in fabricating fibers was obtained theoretically by applying the thermal diffusion. It has been made clear that both fourth and sixth order coefficients in refractive index distribution can be their optimum values for low aberration simultaneously.

In this paper, a numerically exact analyzing method is formulated for the diffused optical waveguide which consist of anisotropic or isotropic medium. By this analytical method, the guided modes of the diffused waveguide are determined and a measurement method for the diffusion coefficient is proposed as an application of this analysis. In the case that there is gradient of the dielectric constant, the exact analysis of the TM-modes is ordinarily difficult. In this analysis the index distribution for the anisotropic medium whose optical-axis is perpendicular to the waveguide or parallel to the waveguide-axis is sliced into multi-layers for successive numerical calculation. It is found, from the waveguides can be discussed with the equivalent film-width defined analytical results, that the propagation properties of the diffused in this paper which is analogous to that of the slab-waveguides. The diffusion coefficients and the activation energies of T1 and Ag in a fused-quartz and Vycor glass are measured with application of the analytical results.

It was found that an oxide power-epoxi resin mixture is an optimum material for surface acoustic wave absorbers oberlayed on LiNb03, Using a SAW device with edge reflection absorbers of this mixture for an FM discriminator, 0.05% distortion at 10.7 MHz center frequency, and 75 KHz frequency deviation, were obtained.

This article gives the realization of floating pure inductance using two operational amplifiers and four capacitors, and some examples of its applications. It also includes investigations of the maximum permissible value E1max of the input voltage of this circuit.

The paper considers the fault tree evaluation using the list processing technique. A tree sequence is newly introduced as a representation of the fault tree; it represents completely the branching structure of the tree. The properties and algorithms concerning the tree sequence are indicated. A method for computing the probability of occurrence of the top event is presented, which is featured by the recursive implementation of partition and reduction of the fault tree, through the combined use of the reverse Polish sequence and the tree sequence. This method enables us to evaluate the fault tree containing not only common primary events but also mutually exclusive primary events. By this method we can obtain the results in reasonable computation time for a fairly large scale fault tree having a few hundred primary events. The method can also be used for sensitivity analysis.

This paper descrives a deterministic parse algorithm for a context-sensitive language. The algorithm is an extension of the Cocke-Kasami-Younger's parse algorithm for a contest-free language to an algorithm for a context-sensitive language. The execution labor by the algorithm is more than 0(n3) for an input with length n.

This letter deals with a horn for radiating focused surface acoustic waves launched from circular arc interdigital electrodes into a narrow waveguide. A simple method of designing a horn using geometric optics was given and some experiments using a v/v waveguide were performed.

In this paper, the electrochemical device is introduced, the behavior of which is suggested by the chronopotentiometry. A sudden increase in resistance of the device occurs after some charge passes through the device. This novel device inexpensively constructs a ULF rectangular waveform generator together with one O. P. amplifier and three resistors only.