A fundamental method of producing scan animations by a digital computer is described by taking motion trajectories and lengths of light trails of objects as parameters, and examples of scan animation are illustrated.

We derived the optimum receiver structure for an M-ary PSK signal in the presence of Gaussian noise and a single sinusoidal (CW) interfere. And by computer simulation we confirmed that the derived optimum receiver performs better than the standard receiver (which is optimum only to Gaussian noise) in the interference environment.

This letter predicts that multichannel SAW filters can be constructed by using two dimensionally periodic reflective dot array (RDA). A three channel device, where one channel is with direct SAW propagation path and the others are with offset SAW propagation pathes, was constructed for experimental verification.

This letter presents experimentally that the power gain of axial-mode helical antenna can be improved by installing a relatively thin dielectric cylinder outside the helix, and also presented in some theoretical consideration to clarify the above effect approximately.

The new profile-control technique was investigated in regard to the modified CVD method to reduce OH-ion concentration in GeO2-P2O5-doped silica graded-index optical fibers. The new profile-control technique, in which only exygen flow rate is varied for a parabolic radial index profile, was successfully attained by utilizing effects of exygen on properties of the deposited glass layer. Amounts of GeCl4 gases, which do not react with oxygen, exist in the heated zone of a supporting tube and can effectively eliminate H2O contaminations by the new profile-control technique. A GeO2-P2O5-doped silica graded-index optical fiber was obtained, that simultaneously has a high transmission bandwidth of 1.5 GHzkm and OH-ion absorption loss of 0.9 dB/km at 1.39 µm.

In instructional design, designers (or teachers) choose an optimum educational media (or educational system) adaptive to the learners' abilities. Although instructional design has been recognized as one of the important teachers' activities thus far, they left most of it to their individual subjectives. In order to perform the design in an objective way, a new mathematical method is proposed here to discriminate if the concerned educational system will be effective to learners on not. It is based on the use of linear discriminant analysis. However, when we apply it to the discrimination on education, the conventional method is not always appropriate to the field of education because many educational events are fuzzy, thus it requires refinement. From the point that the author regards the fuzziness proper to education, in order to aid teachers' instructional designing in an objective way, this paper presents a new logic which fixes linear discriminant function, the equations of error probability and Maharanobis' Generalized Distance considering the fuzziness.

The algorithm for the fast Walsh-Hadamard transform (FWT) derived from the Walsh-Paley function provides fast and simple processors which calculate the i-th Walsh transform Fi (i0, 1, , 2n1) of the natural-, dyadic-, and sequency-ordered Walsh-Hadamard transforms respectively according to control signals. This processor needs only 22n1 adder-subtractors (A/S) and is n times as fast as the one of the iterative type with n iterations. The characteristics of FWT with the term T resemble that of the assembly of digital filters. The digital filter representing FWT can be analyzed with z-transform and its transfer function is described as a simple function of z. The 3 dB bandwidth calculated by FWT is almost constant (about 0.85/T) for n2, 3, ...,10. All the Walsh transform Fi can be calculated by the processor with n2n A/S, while the processor using delay lines needs only 22n1 A/S. The improved processor with delay lines deals with successive data and calculates all the Walsh transform or the Walsh spectrograms at the same time. These processors are effective for the recognition of speech and the analysis of signals.

Bit error rate (BER) performance of convolutional coding/soft decision Viterbi decoding is investigated theoretically. Firstly, equations are derived to calculate the tight upper bound of the BER performance for the multi-level soft decision with arbitrary threshold spacing, considering the quantized metric used in the Viterbi decoder. Experimental results on the BER performance of a rate 1/2 code with constraint length 7 are shown to demonstrate that the derived equations provide the precise BER performance. Then, the BER performance of various codes is calculated for 4- and 8-level soft decision as well as hard decision and ideal (infinite level) soft decision. The codes examined in this paper cover typical codes with 64 states of rate 1/4 through 3/4 and the rate 1/2 codes with constraint length 3 through 14. From the BER curves obtained for these codes, the coding gain is clarified as a function of coding rate and code constraint length. Main results obtained in this paper are as follows. (1) Among codes with 64 states, rate 1/3 code gives the maximum coding gain. (2) Coding gain of a rate 1/2 code increases as constraint length K becomes large. In the case of 8-level soft decision, for instance, the coding gain of the code with K14 reaches 7.1 dB at BER10-6, which is close to the maximum coding gain obtained by an infinite constraint length code (estimated to be 7.9 dB).

An improved numerical solution method for Bayesian estimation in nonlinear image restoration is presented. The constraint condition for the previous Bayesian method is also derived only in a simplest case. This method are shown to be more practical than the previous restoration methods.

In digital satellite communication systems, the high power amplifier (HPA) in the satellite repeater and earth station should operate in the vicinity of the saturation point, in order to effectively use output power. Recently, the adoption of constant envelope modulation schemes, like minimum-shift-keying (MSK) and MSK-type modulation (i.e. modified MSK), have been considered to avoid nonlinear harmful influence. This paper describes a new MSK-type modulation scheme, called Gaussian filtered and amplitude limited MSK (GLMSK). The idea behind GLMSK is to remove the envelope variations of the filtered MSK at the modulator by using a limiter with a small AM-PM conversion coefficient. GLMSK performance is calculated and estimated on some parameters, and the implemented GLMSK modem operation and performance are shown at a nominal data transmission rate of a 100 Mbit/s and an intermediate frequency of 1.7 GHz. Constant envelope GLMSK with a narrow spectral band can be achieved by using conventional high-speed MSK modem techniques.

The discrete Josephson junction transmission line which has N series Josephson junctions in each loop is discussed by computer simulation. It is found that a single quantum in this line can be stuffed in about one loop even if the inductance of each loop decreases to be negligibly small, i.e., the contribution of flux to a fluxoid is decreased. In this line the very small size fluxoid quanta with little flux can be employed as information bits. The resistive Josephson transmission lines whose loops have resistances in series are also discussed. In the resistive lines various operations are possible because of relaxation of the quantization conditions.

A nonlinear model of the basilar membrane (BM) is examined for the two-tone suppression (TTS). The authors tested the BM displacement, velocity and acceleration as a possible candidate of the stimulus to the hair cell. Only in the BM acceleration TTS was observed, that has quite similar tendencies to physiological data.

A fault location test set applicable to a submarine cable has been developed. This is capable of estimating the distance between a fault and the repeater adjacent to it by utilizing the nonlinear modulation characteristic of the repeater which fluctuates periodically at a fixed frequency.

We carried out a research for the responses of Pb thin film microbridge Josephson device fabricated by electron lithography under microwave and millimeter wave radiations. The experimental results are reported in this paper.

Microwave modulation in frequency region of 5.9 to 10 GHz was determined in TJS and BH lasers. Incident microwave power was less than 32 mW at 10 GHz. Modulation mechanism was regarded to be caused by driving of the injected-carrier-dencity even at such high frequency.

Use of parity-based codes in computer systems can provide a cost-effective error detection and correction. Excellent parity-based main memory codes, such as odd-weight-column SEC-DED (Single bit Error Correcting Double bit Error Detecting) codes, can be used to arithmetic logic unit (ALU) by the technique proposed in this paper. They are more economical and better suited for a byte-sliced design of fault-tolerant computer systems than residue codes and triplication organization.

In many packet switched networks, packet sizes are basically 128 or 256 bytes, probably due to their adaptation to interactive communications with short delay requirement. However, in order to deal with message communications also, characterized as bulk, unidirectional and delay tolerable, the networks may be required to handle a larger packet size suitable for the message communications characteristics. This paper calls packet switching systems, which handle various sizes of packets, heterogeneous packet switching systems. Focusing on packet transfer cost in heterogeneous packet switching systems, this paper discusses an optimum packet size for message communications. For an optimum packet size, an approximate and analytical solution is obtained when packet header length is ignored. Moreover, strict and numerical calculation results under a general condition are also shown. It is shown that the approximation gives a smaller size than the strict solution. Further, the effect of cost reduction caused by an optimum packet size for message communications is evaluated. As a result, the cost in heterogeneous packet switching is confirmed to be reduced to about half, especially when message communications traffic is dominant.

In this paper, it is presented that the experimental results of the magnetic bubble propagation in dual conductor current access test circuits, where the bubble-driving fields can be generated by applying the bipolar pulse currents to the apertured conducting sheets. Under the driving conditions that the current density for the first conducting sheet (I1) was at 0.5 mA/µm, for the second conducting sheet (I2) was at 1 mA/µm, and the frequency of these currents was at 200 kHz, the bias margin for the propagation normal to the currents flow was obtained as much as 5 Oe.

This paper investigates the linearity performance of analog video transmission systems which use semiconductor laser diodes. The main origins of system linearity degradation are shown to be reflected laser light and speckle noise. It is demonstrated that a laser with an external reflector produces a nonlinear response which degrades the laser modulation properties. It is also revealed that in analog video transmission systems using graded-index multimode fibers, speckle noise is so serious that a reduction in laser coherency is essential, and a new technique employing an optical feedback scheme to reduce speckle noise in investigated. The high quality of results obtained from transmission tests employing the proposed method have confirmed the feasibility of analog video transmission using semiconductor laser diodes.

As the structural information of characters and figures, features based on closed curves have been used. However, studies of feature extraction methods have been made mainly for a single closed curve. In this paper, a fundamental computer processing system is reported for dealing with very many collections of multiple closed curves which are represented by contour lines of a topographical map. Here, we describe an algorithm for obtaining every string of chain-codes which is local information of a collection of closed curves and a tree structure which is global information of the collection through one directional and a single row-by-row scan. Finally, the results obtained from the application of the proposed algorithm to simple recognition problems of mountains are described.