We propose the notion of noise to a biological system without interactions, and define the adult language with noise which is a generalization of the regenerative adult language by A. Walker. This leads to another L-system theory characterization of well-known families of EOL, and ETOL languages in terms of the adult language with noise.

This paper gives another canonical section of degree four for reactance one-port synthesis.

This paper describe a new analysis on nonlinearity of a satellite born transponder by using Chebyshev transform technique and shows that the nonlinearity is measurable even in case of the satellite being on orbit and/or an AGC amplifier being equipped in the transponder.

In this paper, we characterize the structure generating function of a strongly connected automaton. It is proved that poles of the minimal absolute value of the structure generating function are , e2πi/h, , e2πi( h 1)/ h where h is the period of a strongly connected automaton and r is the Frobenius's root of its incidence matrix. This result is a specialization of Berstol's result which characterizes the structure generating function in general. His method is based on the analysis. But we prove our results using some facts in linear algebra and graph theory. And we obtain analogous results for an automaton by considering the strongly connected automaton which contains as a subautomaton.

Proximity effect correction techniques are well known as being indispensable for drawing submicron integrated circuit patterns using electron beam equipment. This paper discusses one such technique, Pattern shape adjustment", or PSA". Proximity effect correction can be mainly classified into two methods - exposure dose intensity varying and pattern shape modifying. PSA is one variety of pattern shape modifying. This paper clarifies the problems and limitations of the PSA technique, shows its effectiveness and compares it with corrected and uncorrected EB pattern drawing.

A finite element method is used to analyze the vibrational characteristics of a quartz crystal tuning fork. From the information obtained by the calculation, the base length of a symmetrical tuning fork can be determined for stability of the fundamental resonant frequency and for very small stresses at the base end. Moreover, the quantitative reason why the effective resonant quality factor Qe of the supported tuning fork with arm corners cut off is highly promoted becomes clear from the analysis in this paper. This desirable characteristic is also realized in the tuning forks either with the circle hole at slit end or with the wide base portion. As for an unsymmetrical tuning fork which is frequently made in manufacturing process, the effects of dimensional unsymmetry on the resonant frequency are analyzed. For compensation of its characteristics caused by unsymmetry, the method of adjusting the length of an arm is usually adapted. It is ascertained whether or not this method is effective for high Qe and high stability of the resonant frequency against change of support condition.

A minimum phase split-electrode CCD lowpass filter having a considerably reduced number of taps was designed and fabricated. Calculated frequency responses with varieties of tap gain errors and observed response were compared. Reducing the number of taps was shown to be less sensitive to tap gain errors.

A congestion control method for international packet switched networks, which strengthens packet flow restrictions to virtual calls in a congested outgoing route in a switch gradually, is proposed. Basic traffic characteristics of the system under the proposed congestion control are analyzed theoretically. A simple queuing model is developed and state probabilities of the system under the congestion control are obtained analytically. Using the probabilities, equations to evaluated the performance of the congestion control such as throughputs and buffer overflow probabilities are derived. Several numerical examples are obtained and which show the effectiveness of the proposed congestion control method. Packet flow restrictions can be strengthened from virtual calls with low priorities first. By making the number of virtual calls which are controlled simultaneously small, the amount of processing loads for carrying out congestion controls can be decreased. A mechanism for realizing the proposed method is also discussed.

In this paper, we report the calculations of the quantum efficiencies of new types of photodiodes that have the ability to demultiplex the incident light beam into two or three independent outputs according to its wavelength, and determine the diode parameters that give maximum efficiency and low crosstalk. Two types of diodes were fabricated with LPE grown InGaAsP/InP quaternary system which is one of the most useful materials in the 1.01.7 µm low-loss spectral window of optical fiber. One diode divides the input light beam into two outputs and the other does in three outputs. The experimentally obtained spectral responses of the diodes were in good agreement with the calculated ones. The fabricated diodes exhibited nearly 100% internal quantum efficiency and crosstalks of 34 dB at λ1.0 µm and below 50 dB at λ1.35 µm, respectively, where the efficiencies of two outputs take their maximum values.

A simple and practical method for arithmetic computations in a finite field GF (pn) is presented. Since number of elements of GF (pn) is pn, the method uses representation of a field element as an integer modulo pn. The method also uses log and antilog tables. Only one n-th of memories are required to store the log and antilog tables of this paper in comparison with ordinary log and antilog tables. It is not necessary to compute by using vectors. It is also shown that Zech's logarithm defined by Conway can be easily computed by using the log and antilog tables of this paper. The results of this paper are useful for decoding error-correcting cyclic codes.

Error correcting and/or error detecting codes have been successfully used to improve the reliability of computer memories. To improve for error control in memory systems organized to have b bit per package, a new class of linear codes for simultaneous error correction and error detection is given. We refer to a group of b bit as a byte. This paper provides a new class of binary error correcting codes to correct single bit errors and detect single byte errors (SEC-Sb ED codes), and to correct single bit errors and detect double bit errors and single byte errors (SEC-DED-Sb ED codes). Also, an improved byte error correction method which is called erasure correction method is proposed using the SEC-Sb ED codes. The decoders for the proposed codes require very small amounts of extra circuitry over that required for SEC-DED (Single Error Correcting-Double Error Detecting) codes. The decoding speed is very high-equal to that of SEC-DED codes. The proposed SEC-DED-Sb ED codes for b4 require about one more check bit and for b8 require about four more check bits than SEC-DED codes.

Measurements of a far-field gain of a large Cassegrain antenna with shaped reflectors by defocusing method are discussed. Defocused-path-length variation of a shaped antenna does not considerably differ from that a conventional Cassegrain antenna. In a model antenna, even when the maximum spherical phase error is 180 degrees, defocusing method can give the far-field gain within 0.1 dB error, if the illumination does not change by defocusing.

The theoretical approximate model for packet switching multi-access system: the periodic reservation ALOHA (PR-ALOHA) is described. The performance tradeoffs of PR-ALOHA are discussed with analytic results using an approximate model obtained in this paper. By using these results, the optimum design parameters which maximize the channel utilization are given. Numerical results indicate that the PR-ALOHA offers the best throughput-delay performance at the medium throughput region.

Fine adjustment of wide-bandwidth SAW filter responses by trimming the interdigital transducer finger lengths was successfully achieved. In SAW devices, second-order effects, such as end effects, diffraction and bulk mode generation, disturb the simple design performances. The slight difference in wide-bandwidth frequency responses between the theoretical and experimental responses was modified by trimming the IDT finger lengths by hand.

A novel energy relation in eigen modes of transmission line is herein proposed and the variational expressions for propagation constant of various transmission lines can be systematically derived through this relation.

The problem of concurrent access to an index structure is that of allowing a maximum number of processes to operate without impairing the correctness of their operations. Recently, Bayer et al. (1977) presented some simple locking protocols to the problem of concurrent access to indexes which are implemented B*-trees. In this paper, we give a new locking protocol that achieves higher concurrency than that of Bayer et al., by minimizing the area on which the exclusive locks are placed. We also show that this solution is deadlock free.

Some practically optimal conditions for coexistence of analog and digital systems in an intersystem interference environment may be found in a compromise between both systems. To find them, as a first step we have investigated and discussed the effects of multiple wideband FM systems upon an M-ary coherent PSK system under the assumption that both systems are sharing the same radio frequency bands. For that, in this paper we propose an analysis method which is directly applicable to the wideband FM interferers. The symbol error performance of MCPSK system in the presence of Gaussian noise and cochannel or adjacent channel interference from wideband FM systems is evaluated and given in graphes as functions of CNR, CIR and normalized carrier separation. From the results obtained here, one can expect some optimal or suitable operating conditions (frequency allocation, bandwidth and power) for a PSK channel in the intersystem interference from analog FM channels.

Optimum inspection schedule is discussed to maximize the availability for a two-unit parallel redundant system when a failure of unit is detected only by actual inspection. The stationary availability is derived by applying Piecewise Markov Process under the assumption that a failure distribution is exponential and other distributions are arbitrary.

Dynamic properties of electrical circuits containing a Josephson junction are studied analytically by approximating the sinusoidal current-phase relation by a triangular one. Analytical expressions are obtained for the circuit-parameter dependences of transient voltage waveforms, ac ripples of stationary-state voltage oscillation and minimum currents in several typical circuits, which are shown to be in good agreement with numerical results. It is also shown that these quantities can be well characterized in simple forms in terms of a frequency peculiar to each circuit.

Average intensity of far-field radiation patterns of laser light emitting from an end face of the multimode optical fiber is theoretically analyzed by assuming a Gaussian autocorrelation function for the refractive-index inhomogeneities in an optical fiber. The average intensity distribution of far-field patterns is characterized by both the statistical scale of index fluctuations and the fiber parameters of core radius and refractive-index profile. It is shown that the on-axis maximum intensity decreases as the correlation length of refractive-index inhomogeneities becomes small compared with the wavelength of light, whereas the off-axis average intensity decays gradually with the increase of the distance from the axis. The average intensity distributions obtained here are found to be nearly Gaussian for both types of the optical fiber with step-index and graded-index profiles of the refractive index.