In the present paper, we introduce a new type of automata, called generalized group-matrix type automata, for representing general automata in connection with their automorphism groups. A family of subgroups of a given finite group, satisfying a certain condition, called the separation condition, will play a fundamental role.

A method of exact analysis for the cylindrical fiber with an arbitrary but azimuthally symmetric refractive-index distribution is given. The index distribution is simulated by a multilayer structure and the analysis is formulated exactly by using iterative multiplication of four by four matrices. Then the four by four matrices are approximately separated into two systems of two by two matrices with a good accuracy for the fiber with small index difference. In this way, the computing time is reduced almost 1/6 times compared with the former method. As an example of the application, the propagation modes of a focusing fiber are identified which previously were not exactly known. It is revealed that the group-velocity differences between the modes which are degenerate in the scalar analysis can be larger than those of the non-degenerate modes.

Silicon avalanche photodiode with the Nπ1Pπ2P structure is fabricated, using the technology of epitaxitial growth after boron ion-implantation to bury a P layer. The diode with the excess noise factor of F5 is obtained at the multiplication factor of M100 for λµm.

To know the correlation between the surface contamination of semiconductors and electrical properties of semiconductor devices fabricated on the surface, the contamination of chemically etched Si surface was measured by Auger electron spectroscopy (AES) and Schottky contact was formed by evaporation of Au on that surface in situ. The various chemical etchants were used, including HF, HNO3, CH3COOH, their mixture, and alkaline etchant. The saturation current, the barrier height, and the n-value of the forward current-voltage characteristics of Au-Si Schottky contact were used for evaluating device characteristics, and in-depth profile of composition of the metal film on Si was also measuring by AES combined with ion-sputter etching. Following results are obtained; The barrier height of the Au-Si Schottky contact whose Si surface is contaminated by carbon is low and 0.810.02 eV, and not far from that of clean surface. On the other hand that of Si surface not so much contaminated by carbon but by oxygen is large and 0.830.01 eV, and the n-value is close to unity. This phenomena can be explained by assuming the vanishing of surface states of Si surface with small oxygen adsorption. This model cannot be applicable to heavily contaminated surface. The results of composition analysis show that a small amount of oxygen passivates Si surface and gives high barrier height.

Single material fibers made from low loss material may have excellent optical propagation properties related to absorption loss. Thin film fibers with a convex surface have self focussing properties similar to those of inhomogeneous fibers with quadratic index profile. Such optical waveguides seem to be useful for optical communications and integrated optics. By using the method of conformal mapping, fundamental characteristics of guides modes along optical films with a convex surface are found, and field distributions and dispersions of eigen modes that have not been clarified are shown in detail. These guided modes have Hermite Gaussian field distribution in transverse direction. The spot sizes of guided modes are inversely proportional to the square root of the product of their transverse wave number and the metrical coefficients (1a)lx, where β1 and β2 are phase constants of the material and the guided mode respectively. The factors (1a)lx derived from mapping function and are quadratic coefficients of the convex surface at the fiber boundaries. The dispersion characteristics of the guided modes are discussed and several numerical examples are presented.

The purpose of the present note is to provide a necessary and sufficient condition in order that strongly connected group-matrix type automata, whose orders are prime, may be regular. Further, as an applications, a problem concerning factor automata of a strongly connected automaton will be discussed.

This paper describes that in numerical solutions of electrostatic field problems, the difference equations which are derived from two processes to approximate the field equation will be different from each other when unequal mesh size is used. Also accuracies are discussed for cylindrical condenser.

This paper describes an investigation of the SAW beam diffraction on LiNbO3 crystal by the frequency-translated-holographic technique, which allows direct observation of SAW amplitude distributions. The observed diffraction patterns are found to change as a function of excitation frequencies, and to agree well with the theoretical amplitude distributions of the SAW's emitted from the multiple finger pairs of an interdigital transducer. The method of the angular spectrum of plane waves was used for the theoretical computations.

A digital technique for evaluating the half-power band-width of a resonance system is presented. It is based on the lateral shifting operation of the z-transform of the samples sequence on the z-plane. The shifting operation is carried out by using the binomial coefficients.

A synthesis technique is presented for the multiple feedback (MF) active RC realization of transfer functions having complex frequency transmission zeros, and a biquadratic block in the MF structure is proposed, which is suitable for realizing the internal transfer function having complex zeros and poles.

The electron density profile in the lower ionosphere was determined from the right and left handed circular polarized wave fields of the 40 KHz ground based signal observed by means of a rocket borne receiver. The determination of the electron density from 70 Km up to 100 Km was made under the condition for the values calculated by the full wave analysis to agree with the observed values.

This paper investigates problems associated with relaxation oscillation and output powers in homogeneously broadened four-level lasers having nonuniform population inversion and photon densities along the laser axis. The rate equation for the population and photon number of four-level lasers has been solved with considering the diffusion of excited states. Numerical solution shows that the energy migration between lattice sites significantly increases the frequency and damping constant of the relaxation oscillations together with the obtainable power from the spatially hole-burned lasers.

Single axial mode oscillation in Integrated Twin-Guide AlGaAs laser fabricated by sputter-etching was observed by current injection pumping at room temperature, as predicted by theory.

This short paper treats some decision problems for Petri Nets and shows that the problems of the safeness, the reachability and the proper termination are NP-complete for Petri Nets in which each transition fires at most once.

Let J{1, 2, , n} be a set of jobs. Each job j can be processed on one of the m identical machines in one unit time, and has ready and due times. It is shown that the problem of finding an optimal schedule minimizing the sum of costs associated with jobs j, which are monotone functions of completion time of j, can be reduced to the assignment problem with 0(n) vertices; hence it can be solved in 0(n3) steps. As important special cases, this cost includes the weighted number of late jobs, the weighted tardiness, and the weighted flow-time. In addition, it is shown that the problem has an 0(n log n) algorithm if the objective is to minimize the (unweighted) number of late jobs. This problem is critical for having an efficient algorithm in the sense that generalizing it in various directions easily results in NP-complete problems. As an example, it is shown that it becomes NP-complete if precedence constraints are imposed.

EPISC (ETL's pattern information computing systems) is a computer system developed at ETL(Electrotechnical Laboratory) for pattern information research in the national project PIPS (Pattern Information Processing System) inaugurated in 1971, and is intended to be an original guide of PIPS Prototype the target of the Project. It has been implemented toward an in-house computer network, and is a star structured computer complex in which main and sub-computers communicate through high speed channels. For computer communication in EPICS, two levels of protocol are provided. Low level protocol is carried out by a newly developed hardware Computer Communication Controller and a resident module controlling it. High level protocol provides system services for an interface between user processes and EPICS control system. Those functions include remote job entry, file control and processes synchronization and are carried out by a non-resident module. Described are what kinds of high level protocol are well used for computer communication and that protocol sequences are reduced to five simple patterns observed as everyday occurrences in EPICS. Usage patterns of high level protocol sequences depend on experiment environments among work groups rather than on their research field.

A method for analyzing the input- and parameter-sensitivities of a broad class of nonlinear continuous systems with nonlinear feedback couplings is proposed. This method is carried out first by formulating the problems in the form of nonlinear integral equations, and then evaluating the solutions by applying fixed point theorems in the appropriate Banach spaces. The actual analysis in this paper is accomplished for the entire function type of nonlinear integral equations, making use of Banach's contraction operator principle, Schauder's fixed point theorem for completely continuous operators and the Leray-Schauder rotation concept of completely continuous vector fields. These procedures can be regarded as systematic and simple even for practical analysis of complicated systems.

A simple but enough accurate approximate formula is derived which gives the maximum power density of an FM wave modulated by a multi-channel telephony signal with a medium modulation index. This formula may be used by an administration who intends to establish communication system and shall send the information of the maximum power density at the input of the antenna to the International Frequency Registration Board in accordance with the Radio Regulations.

Phase-matched film thickness are studied precisely for SHG in a nonlinear quartz-glass waveguide. The glass film waveguide deposited upon the surface of quartz suffers non-uniform stress due to the thermal expansion. This effect generates an anisotropic property in the film. Taking this anisotropy of the glass film into account, the observed film thickness for phase-matched condition results in good agreement with the theory.

Using a tilted electric field (TEF) soft-landing collector, one of the authors has achieved an efficiency improvement of a TWT from 11.8 percent to 43.0 percent. However, the TEF collector requires a uniform magnetic field covering the entire collector space, and hence, a heavy magnet or electromagnet, which is far from practical in high-power tubes. This paper proposes the periodic magnetic field (PMF) soft-landing collector, which is a periodic field version of the TEF collector. It requires much lighter magnets than a TEF collector does. The principle, design theory, preliminary low-perveance experiment, and a relevant computer simulation are presented. Finally experiments with a medium-power UHF TWT equipped with a PMF collector are described.