Precise measurements of temperature dependence of the Andreev reflection current for the N–I–S junctions were carried out. Au and Pb were used as N (normal metal) and S (superconducting material), respectively. The experimental results agreed with the analyses based on the Arnold theory.

By applying Wigner distribution, which has high time resolution and high random noise reducing capability, to the acoustic bio–signals, the possibility of early diagnosis in both intracranial vascular deformation and prosthetic cardiac valve malfunction increased. Especially in latter case, 1st–order local moment of the distribution showed its effectiveness.

A new leaky surface wave on lithium tetraborate that propagates along the surface with a higher phase velocity than that of ordinary leaky surface waves, radiating two bulk wave terms into the solid, is described.

Transistor stuck–open faults in CMOS devices are such that they force combinational circuits to exhibit sequential behaviors. It has been proved that, in general, stuck–open faults can not be modeled as stuck–at faults and, therefore, a sequence of two consecutive test vectors is necessary to guarantee stuck–open fault detection. In this paper we propose a technique to modify CMOS circuits in such a way that any stuck–open fault in the circuit can be detected using only a single test pattern. The amount of additional logic required to achieve the goal is rather limited: Two pass transistors, one input line, and one inverter (or buffer) at the output of the circuit are sufficient to make stuck–open faults detectable by test patterns generated by usual stuck–at fault test generators.

The warp model of the extended Hough transform (EHT) has been proposed to design the explicit expression of the transform function of EHT. The warp model is a skewed parameter space (R(µ,ξ), φ(µ,ξ)) of the space (µ,ξ), which is homeomorphic to the original (ρ,θ) parameter space. We note that the introduction of the skewness of the parameter space defines the angular and positional sensitivity characteristics required in the detection of lines from the pattern space. With the intent of contributing some solutions to basic computer vision problems, we present theoretically a dynamic and centralfine/peripheral-coarse camera vision architecture by means of this warp model of Hough transform. We call this camera vision architecture askant vision' from an analogy to the human askant glance. In this paper, an outline of the EHT is briefly shown by giving three functional conditions to ensure the homeomorphic relation between (µ,ξ) and (ρ,θ) parameter spaces. After an interpretation of the warp model is presented, a procedure to provide the transform function and a central-coarse/peripheralfine Hough transform function are introduced. Then in order to realize a dynamic control mechanism, it is proposed that shifting of the origin of the pattern space leads to sinusoidal modification of the Hough parameter space.

Fractal image coding using iterated transformations compresses image data by exploiting the self–similarity of an image. Its compression performance has already been discussed in [2] and several other papers. However the relation between the performance and the self–similarity remains unclear. In this paper, we evaluate fractal coding from the perspective of this relationship.

Bifurcations of quasi–periodic responses in an oscillator described by conductively coupled van der Pol equations with a sinusoidal forcing term are investigated. According to the variation of three base frequencies, i.e., two natural frequencies of oscillators and the forcing frequency, various nonlinear phenomena such as harmonic or subharmonic synchronization, almost synchronization and complete desynchronization are ovserved. The most characteristic phenomenon observed in the four–dimensional nonautonomous system is the occurrence of a double Hopf bifurcation of periodic solutions. A quasi–periodic solution with three base spectra, which is generated by the double Hopf bifurcation, is studied through an investigation of properties of limit cycles observed in an averaged system for the original nonautonomous equations. The oscillatory circuit is particularly motivated by analysis of human circadian rhythms. The transition from an external desynchronization to a complete desynchronization in human rest–activity can be referred to a mechanism of the bifurcation of quasi–periodic solutions with two and three base spectra.

An efficient full–wave spectral domain moment method is developed to compute the current distribution and the radiation associated with microstrip discontinuities. Two techniques are used to increase the efficiency of the method of moments algorithm so that a transmission line of moderate electrical size can be analyzed in reasonable time.

It is shown that a self–recurrent fuzzy inference can cause chaotic responses at least three membership functions, if the inference rules are set to represent nonlinear relations such as pie–kneading transformation. This system has single input and single output both with crisp values, in which membership functions is taken to be triangular. Extensions to infinite memberships are proposed, so as to reproduce the continuum case of one–dimensional logistic map f(x)=Ax(1–x). And bifurcation diagrams are calculated for number N of memberships of 3, 5, 9 and 17. It is found from bifurcation diagrams that different periodic states coexist at the same bifurcation parameter for N9. This indicates multistability necessarily accompanied with hysteresis effects. Therefore, it is concluded that the final states are not uniquely determined by fuzzy inferences with sufficiently large number of memberships.

The problem of electromagnetic scattering by inductive discontinuities located in rectangular waveguides, in particular when dealing with discontinuous conductors of finite thickness, is analyzed using the modified residue-calculus method, and form of the equation suitable for a numerical calculation is derived. The incident wave is taken to be the dominant mode, and reflection and transmission properties of an asymmetric inductive iris are discussed. After the modal representation of the filed, the modal matching is apply to satisfy the boundary conditions at the discontinuity. And using the modified residue-calculus method, simultaneous infinite equations, which are concerned with the scattered mode coefficients, are derived. Then they are approximated at the thick diaphragm. The solutions obtained take on the form of an infinite product, and a numerical solution based on the method of successive approximations is presented as a technique for concretely determining the reflection coefficients. As confirmation, experiments are also carried out in the X-band and close agreement is shown between the calculated and experimental values.

In an image fiber containing a large number of cores, a certain class of crosstalk has been found to decrease with the distance along the fiber axis. This crosstalk is absolutely distinguished from the usual crosstalk that increases with the distance. A theoretical model is presented based on the power transfer between three groups of modes supported by each core. The process of power transfer is described by coupled power equations. Values of the coupling coefficients can be determined from the measurement of the crosstalk. The equations are solved numerically for the transmission of a point image. The results are in good agreement with measurement results.

The mechanical impedance of silicone–gel model or chest surface has been measured and the viscoelasticity and effective vibrating radius have been obtained from the impedance. They depend on the distance between the internal block of the silicone–gel/ribs of right chest and the gel surface/skin surface. The 3–D image of internal structure is reconstructed, based on the relation between the distance from the surface and the effective vibrating radius.

In this paper, the dispersion characteristics of magnetostatic surface waves (MSSW) in a nonlinear gyromagnetic medium are analytically investigated. Assuming the nonlinearity as the first order perturbation in permeability tensor of the gyromagnetic medium, the perturbation technique based on the multiple scale method is used to deduce the nonlinear dispersion relations for the MSSW. It is observed that for a given propagation constant of the MSSW the frequency decreases with microwave power. It is also observed that group velocity decreases, and as a consequence, delay time increases with power of the microwave. By evaluating the dependence of frequency on power and variation of group velocity on propagation constant within the accuracy of the perturbation theory, it is confirmed that the conditions for formation of bright soliton are not satisfied for the MSSW.

For medical imaging, non-rigid motion analysis of the heart deformability is a nontrivial problem. This paper introduces a new method to analyze the gated SPECT (Single Photon Emission Computed Tomography) imges for 3-D motion information of left ventricular. Our motion estimation method is based on a new concept called normal direction constraint" in that the normal of a surface patch of some deforming objects at certain time instant is constant. This paper consists of the following processes: contour extraction, slices interpolation, normal vector field generation, expanding process, motion estimation for producing a 2-D motion vector field, and deprojection for a 3-D motion vector field. In the experiments, we will demonstrate the accuracy of our method in analyzing the 3-D motion field of deforming object.

A new algorithm, which is incorporated into the waveform relaxation analysis, for efficiently simulating the transient response of single lossy transmission lines or lossy coupled multiconductor transmission lines, terminated with arbitrary networks will be presented. This method exploits the inherent delay present in a transmission line for achieving simulation efficiency equivalent to obtaining converged waveforms with a single iteration by the conventional iterative waveform relaxation approach. To this end we propose 'line delay window partitioning' algorithm in which the simulation interval is divided into sequential windows of duration equal to the transmission line delay. This window scheme enables the computation of the reflected voltage waveforms accurately, ahead of simulation, in each window. It should be noted that the present window partitioning scheme is different from the existing window techniques which are aimed at exploiting the non–uniform convergence in different windows. In contrast, the present window technique is equivalent to achieving uniform convergence in all the windows with a single iteration. In addition our method eliminates the need to simulate the transmission line delay by the application of Branin's classical method of characteristics. Further, we describe a simple and efficient method to compute the attenuated waveforms using a particular form of lumped element model of attenuation function. Simulation examples of both single and coupled lines terminated with linear and nonlinear elements will be presented. Comparison indicates that the present method is several times faster than the previous waveform relaxation method and its accuracy is verified by the circuit simulator PSpice.

On ranging system on short distance using spread spectrum, we examine waveform responses to predict the state of electromagnetic waveform propagation while the signal is received after scattered by a target. Then this system and the numerical results are discussed.

This paper proposes a methodology for fine evaluation of the uncertain behaviors of systems affected by any fluctuation of internal structures and internal parameters, by the use of a new concept on the fuzzy mapping. For a uniformly convex real Banach space X and Y, a fuzzy mapping G is introduced as the operator by which we can define a bounded closed compact fuzzy set G(x,y) for any (x,y)∈X×Y. An original system is represented by a completely continuous operator f defined on X, for instance, in a form xλ(f(x)) by a continuous operator λ: YX. The nondeterministic fluctuations induced into the original system are represented by a generalized form of the fuzzy mapping equation xGβ (x,f(x)) {ζX|µG(x,f(x))(ζ)β}, in order to give a fine evaluation of the solutions with respect to an arbitrarily–specified β–level. By establishing a useful fixed point theorem, the existence and evaluation problems of the "β–level-likely" solutions are discussed for this fuzzy mapping equaion. The theory developed here for the fluctuation problems is applied to the fine estimation of not only the uncertain behaviors of system–fluctuations but also the validity of system–models and -simulations with uncertain properties.

We propose two methods to fuse auditory information and visual information for accurate sppech recognition. The first method fuses two kinds of information by using linear combination after calculating two kinds of probabilities by HMM for each word. The second method fuses two kinds of information by using the histogram which expresses the correlation of them. We have performed experiments comparing the proposed methods with the conventional method and confirmed the validity of the proposed methods.

We introduce recurrent networks that are able to learn chaotic maps, and investigate whether the neural models also capture the dynamical invariants (Correlation Dimension, largest Lyapunov exponent) of chaotic time series. We show that the dynamical invariants can be learned already by feedforward neural networks, but that recurrent learning improves the dynamical modeling of the time series. We discover a novel type of overtraining which corresponds to the forgetting of the largest Lyapunov exponent during learning and call this phenomenon dynamical overtraining. Furthermore, we introduce a penalty term that involves a dynamical invariant of the network and avoids dynamical overtraining. As examples we use the Hnon map, the logistic map and a real world chaotic series that correspond to the concentration of one of the chemicals as a function of time in experiments on the Belousov–Zhabotinskii reaction in a well–stirred flow reactor.

An emitter–coupled pair with a dynamic bias current and a source–coupled pair with a dynamic bias current are proposed as an exponential–law element and a square–law element that operate as a floating bipolar junction transistor (BJT) and a floating MOS field–effect transistor (MOSFET). In bipolar technology, a hyperbolic sine function circuit and a hyperbolic cosine function circuit are easily obtained by subtracting and summing the output currents of two symmetrical exponential–law elements with positive and negative input signals. In the same manner, an operational transconductance amplifier (OTA) and a squaring circuit are obtained by subtracting and summing the output currents of two symmetrical square-law elements with positive and negative input signals in CMOS technology. The proposed OTA and squaring circuit possess the widest input voltage range ever reported.