The process of light-adaptation with an intense illumination was examined in the carp horizontal cell by using a new approach comprised of two steps. First, light was periodically modulated by pseudo-white-noise and applied to the retina. Second, the statistical properties of reponses corresponding to one cycle (2.5 sec in this study) of stimuli at different times were examined. Our experiments and analyses gave the following results. The dark-adapted L-cells responded with a sudden initial hyperpolarization followed by a small fluctuation superimposed on the slowly declining steady potential. As light-adaptation proceeded, the response fluctuation gradually increased, then slowly decreased and leveled off. During about the first 1 min of light-adaptation, the amplitude distribution of responses departed from normal distribution in symmetry as well as peakedness, then it rapidly approached normal distribution. The equivalent bandwidth of the power spectrum increased monotonically for about 3 min of light-adaptation but then attained a steady state level (45 Hz). The initial increase of the power at high frequencies was related to the nonlinearity and was probably produced in relation to the power at low frequencies. On the other hand, the later increase of the power at high frequencies implies that the cell became to respond to the high frequency components of the stimulating light.

The metal-insulator (tunnel)-n/p+ semiconductor-switch (MISS) device is known to display current-controlled negative resistance in the current density-voltage (J-V) characteristics and can be applied as shift registers, optical switching element, etc. However the effect of optical illumination on the J-V characteristics has not been understood theoretically. In this paper the illumination effects in the three parts of the device, i.e., the p+n junction, the insulator-semiconductor junction and the depletion region of the n layer, are calculated, and the J-V characteristics under illumination are obtained. The fractional voltage drops across the above three parts with respect to the total voltage of the MISS device are calculated under dark and illuminated conditions. It is shown that the minority carrier charge, generated by illumination and stored at the insulator-semiconductor interface, reduces the switching voltage below that under the dark condition which corresponds to entire punch-through.

In the design of digital filters, it is desirable to achieve lower sensitivity. Wave digital filters (WDF's) are considered one solution to this problem, and two design approaches have been proposed. However, WDF's have complicated structures compared with conventional ones. This will make it difficult to implement WDF's. The aim of this paper is to reduce the difficulty owing to the complexity of the network structures. Two kinds of simplification techniques are presented. One is to reduce the number of adders. For this purpose, new series and parallel sections and a new port matching scheme are proposed. The other is to construct WDF's using identical 3-port adaptors except the one to match the port resistance. Examples of WDF's with proposed structures are provided and the effectiveness of the proposed techniques is also shown.

In recent years a lot of attention has been focused on writing error-free programs in an easily readable and understandable manner. It is also recognized that the so called von Neumann" or Imperative" languages may not be the right medium to work in this direction as these have a complex body lacking the solid foundation of computational mathematics. With the announcement of yet another such language, there is a further addition of various new language constructs thereby only helping to build up the confusion. On the other hand, functional languages are based upon a solid foundation and produce programs which are semantically very clear. These language, however, have not found favor with the computing community primarily because these are not history sensitive apart from being inefficient to run on presently available computers. An appearling alternative has been proposed by Backus in terms of an applicative language independent of the lambda calculus and possessing history sensitivity by means of a loose coupling between computation and the state (of the store). In this paper, we pick up his ideas and work up a computation scheme which introduces an amount of abstraction in the representation of variables. Specifically, we do not bind a variable to a particular value to the declared type, but rather we assign limits to the values of the variable. These limits are changeable and depend upon the available semantic information. It is observed that such a scheme can exploit the potentials of working at higher levels, notable among which in this particular scheme is, the possibility of considerable increase in the speed of computation.

In the Value-Added Network (VAN) environment Dijkstra's Dining Philosopher Problem" is extended to a social resource acquisition problem of entrepreneurs and craftsmen where the formers wish to employ, for their projects at hand, certain sets of craftsmen of requisite skills and the latters wish to maximize their chance of employment. This paper sets up a framework of rules for the solution process that compromise conflicts of personal interests, designs communication protocols for message exchanges, and proposes a decentralized on-line algorithm for guiding individual participants toward their own benefits while assuring the solvability of the problem. Although propagation of messages through VAN are restricted in order to reflect an indefinite nature of participation and protection of privacy, the proposed algorithm is capable of activating the maximum number of concurrent resource aquisition as the present conflicting-situation allows.

The characteristic impedances of the slab line with an anisotropic dielectric having a tilted principal axis are numerically presented for sapphire and pyrolytic boron nitride. Moreover, an approximate formula of the impedance for a small wire is also presented by using the numerical data.

A newly developed Josephson logic gate array is described. This gate array has 576 switching devices (Josephson Interferometers) and it has attained the high speed switching time of 33ps with a 2-input OR circuit. Employing and AC-powered latch circuit, the gate array has a single power supply. The total power dissipation of the gate array chip has been estimated to be 2 mW. This gate array includes all the necessary types of function blocks to accommodate any kinds of computer logics. Shift-resistor and 4-bit full-adder circuits have been successfully operated.

It is shown that the previously reported time series analysis using a finite element approximation to the Perron-Frobenius operator can be used to investigate periodic chaos in one-dimensional discrete dynamical systems as well as mixing chaos.

This paper presents a parallel two-dimensional array matching algorithm which can report all occurrences of a given key subarray of size kk within any text array of size nn in n nk1/l steps on lk2 comparator cells, where l(1ln) is the number of matching units. Our algorithm can be regarded as a two-dimensional generalization of Mukhopadhyay's parallel string matching algorithm.

Transient solution of convective diffusion equation in s dimension (s1, 2 or 3) is formulated by boundary integral equation. Fundamental solution to the convective diffusion operator is also presented in uniform velocity field. In particular, the one-dimensional case (s1) is treated because a discussion on the stability of transient solution is very important in practical applications. For discretization of the integral equation, constant and linear elements in time and constant elements in space (internal cells) are employed. A simple time-marching scheme is also developed. In numerical experiments, three model problems are considered. As the result, it is found out that the transient solution is stably calculated in time and space, and that its stability is independent upon the usual criteria that the Courant number C(vΔt/Δx)1 and the diffusion number D(kΔt/Δx2)1/2. In addition, a comparison with the exact solution is given, and the accuracy is discussed.

The realization and the design of three types of low-sensitivity leapfrog switched-capacitor filters (SCF's) are proposed. These SCF's realized with new differential-mode building blocks exhibit an excellent reduction in worstcase sensitivity to component variations. The design for each proposed SCF was confirmed by the experiment. Since the proposed SCF's are all parasitics-compensated, they are realizable in MOS IC forms.

High resolution optical imaging from space is expected to attain further development and achieve greater high grade performance. This paper reports the results of a study for the realization of compact stereoscopic imaging and high efficiency data processing system.

A high-strength, low-linear expansion coefficient tight-jacketed optical fiber is proposed using thermotropic liquid crystal polymer (LCP). The 0.9-mm-diameter LCP-jacketed optical fiber with breaking strength of 51 kg at strain of 3.4% at 25 can be used over the wide 60 to 200 temperature range.

Numerical characteristics of mixed element solutions are studied in comparison with constant and linear elements'. It is shown that mixed elements give accurate solutions as similar to the previous investigations and also the system of equations is better-conditioned than other elements'.

A DC-powered complementary circuit employing interferometers in investigated using simulation. It is shown that an output inductor and two kinds of damping resistors are necessary to suppress circuit oscillations. Switching speed is expected to be less than 25 ps at a current density of 5000 A/cm2 for lead-alloy devices.

Ground clutter from cultivated land was measured using an L-band long range air-route surveillance radar (ARSR) at very low grazing angles, between 0.21 and 0.32. It is shown that the Weibull-distributed ground clutter obeys a Weibull distribution in the frequency domain after processing by the discrete Fourier transform (DFT). Thus the new Weibull-CFAR should be considered to suppress such clutter in the frequency domain.

An iterative decomposition method with mesh refinement strategies is presented for the numerical solution of nonlinear two-point boundary value problems. It is shown that this method is more efficient than the traditional finite difference methods and shooting methods.

A model for computation of the transmission delay distribution in infinite population nonpersistent CSMA/CD is presented, together with computational approximations. Recent extensions of the use of CSMA/CD to heavy load realtime applications, such as packet voice communication and process control, motivated this work. The realtime condition demands quantiles of packet delay distributions, which in turn requires that the entire distribution be calculated rather than representative values such as mean delay and coefficient of variation. The model decomposes into two submodels describing channel state and delay distribution, respectively. The channel model is of infinite population justifying the assumption that the channel behavior affects an individual station's behavior, whereas the converse does not take place. The formulation is by discrete time Markov chain; time is grained into slots or backoff unit time. An arbitrary packet size distribution is allowed. The solution is obtained in closed form; measures such as throughput and probability of trial success are also available in closed form. The delay model assumes that channel access trials are independent of each other; the calculation consists of convolutions and weighted sum of distributions. Because this computation is rather heavy, approximations are included.

Gamma ferric oxide thin film media with a thickness of 0.190.27 µm were prepared by a reactive RF sputtering. Signal output loss with increasing temperature at high recording density was studies. Heating a medium-head system to 55 results in a 16% loss of signal output at 790 bpm (D-6 dB) of recording density for a medium having a 0.19 µm thickness; a 40% loss of signal output for a conventional-coated medium having a 0.7 µm thickness at 400 bpm (D-6dB), accompanying a decrease of a saturation write current value, IW(k-1) (an optimum write current). Increments of medium thickness and write current enhanced the thermal signal output loss. An over-saturated recording in the write process was suggested to cause the thermal signal output loss, especially for the thicker media. From the perspective of thermal stability of signal output at high recording density, sputtered γ-Fe2O3 thin film media are advantageous because of their thinness and small write current dependence of signal output.

A rapid testing is required in clinical laboratory. A new method for rapid bacterial testing is proposed by size distribution measurement with laser light scattering. Bacterial sample is suspended in a saline solution and the scattering pattern is measured from 5 to 90 degrees with 5-degree intervals. The size distribution function is calculated from the light scattering pattern by the inversion technique based on the modified Rayleigh-Debye approximation. The difference in bacterial species and the influences of drug are investigated. The following results are obtained; (1) size distribution curve reflects the morphological characteristics of bacteria, and bacterial species are discriminated roughly by two characteristic parameters (mean size and dispersion width) obtained from the curve; (2) size distribution pattern changes in a short time (within one hour) indicating the effects of drug. It is useful for antibiotics susceptibility testing.