For the quantum state control communication, one of the most serious problems is the effect of transmission loss which degrades the advantage of the quantum state controlled signal. In this paper, we investigate loss effect for the squeezed state signal, which is one of typical quantum state controlled signals. First, it is shown that when the squeezed state signal optimized regardless of the effect of loss is used as transmitter state in the communication system with energy loss, the signal to noise ratio of the received signal is higher than that of the coherent state signal with the same transmitted photon number when and only when the loss is less than 3 dB. Then this paper gives an optimum condition of the squeezed state signal for lossy channel. This optimum condition provides higher signal to noise ratio of the received signal than that of coherent state signal for any degree of loss. Furthermore, we compare the performance of the quantum coherent communication systems using the optimum squeezed state signal with that of the photon communication using the photon number state signal taking the effect of loss into account.

Our primary purpose of this paper is to study attractors and bifurcation phenomenon appearing in an eventually bounded circuit. The secondary purpose is to demonstrate the results obtained from the instruments which display Lorenz maps, Poincaré maps and cross sections of attractors on a synchroscope. The above mentioned circuit contains two non-linear resistors and is written as 3 first order differential equations. Experimental observations show:(a) maximum number of the attractors in three.(b) maximum number of the stable limit cycles is three.(c) maximum number of the chaotic attractor is two.Observed bifurcations are:(a) Hopf bifurcation,(b) period doubling bifurcation,(c) periodic window.Furthermore, we examined the Feigenbaum constant δ experimentally and estimated it at 4.67.

Let γ and n be positive integers. An integer z with gcd(z, n)1 is called a γth-residue mod n if there exists an integer x such that zxγ (mode n), or a γth-nonresidue mod n if there doesn't exist such an x. Denote by Z*n the set of integers relatively prime to n between 0 and n. The problem of determining whether or not a randomly selected element zZ*n is a γth-residue mod n is called the γth-Residuosity Problem (γth-RP), and appears to be intractable when n is a composite integer whose factorization is unknown. In this paper, we explore some important properties of γth-RP for the case where γ is an odd integer greater than 2, and discuss its applications to cryptography. Based on the difficulty or γth-RP, we generalize the Goldwasser-Micali bit-by-bit probabilistic encryption to a block-by-block probabilistic one, and propose a direct protocol for the dice casting problem over a network. This problem is a general one which includes the well-studied coin flipping problem.

Imaging the acoustical nonlinear parameter using second-harmonic and difference-frequency waves produced from finite-amplitude sound propagation is described. Experiments for reconstructing nonlinear-parameter tomograms were performed with gelatine phantoms. The tomograms were not of high quality because we used a small-aperture receiver to detect the substantially refracted waves. We show that by laterally translating the receiver to the position of maximum intensity for each measurement of a point on a projection, we can improve the quality of nonlinear parameter tomograms as well as that of conventional attenuation tomograms. We analyze the effects of attenuation and diffraction for a narrow transmitted beam in nonlinear parameter imaging. Using second-harmonic waves is advantageous for attenuation compensation when the attenuation in the object is proportional to the frequency, such as is the case for soft biological tissue. On the other hand, using difference-frequency waves has certain advantages where attenuation is not a problem. With these waves there is less phase variation.

A design method of multilevel logic networks, in single-rail input logic, with MOS cells for parity functions of n variables is presented. The parity functions x1x2xn in a two level network requires 2n-1+1 gates, whereas the number of NOR gates in a multilevel network for this function is proportional to n. Since MOS cells are playing a major role in LSI and can represent more complex functions than a NOR or a NAND gate, it is possible to obtain smaller networks with complex MOS cells than with NOR or NAND gates. However, if MOS cells become excessively complex, the propagation delay time of MOS cells is too large and the normal operation of the whole MOS network cannot be expected. The design procedure given in this paper is systematic and very easy to apply. In the beginning, the formulation of MOS cells and MOS networks has been presented. In this formulation, the number of series and parallel transistors and the number of MOS cells and levels can be defined and enumerated for MOS networks. Without the restrictions the maximum number of series transistors is the number of input variables, n. With the estriction on the number of series transistors to R, the number of parallel transistors is less than or equal to 2R-1. Furthermore, the number of MOS cells and the number of levels of the MOS network are proportional to n and logRn, respectively. Since the designed network is similar to a complete tree, it would also be useful to process a series of combinations of input variable values.

An observation of a neutral IBW (ion Bernstein wave) modified by a pure IBW in a large space chamber was represented comparing with the theory. The results for the dispersion relation, the excitation coefficient and the maximum damping rate were discussed.

An empirical Bayesian method was used to obtain a point estimator for the reliability function of a bivariate exponential distribution associated to a two-component parallel electronic system.

A discharge fusion splicing technique for fluoride optical fibers has been investigated. Discharge heating conditions were experimentally examined by making a fiber offset from the electrode axis. An average splice loss of 0.14 dB was achieved for 50µm-core fibers.

The authors measured the temperature dependence of the level of the 1/f noise in carbon-black graft-polymer resistors. A distinct dip is observed in the noise level at a temperature at which the temperature coefficient of the resistance is zero. This is in agreement with our temperature fluctuation model on the 1/f noise in resistors which include a large number of small conducting spots.

This paper presents an antenna for the UHF-TV reception consisting of skeleton slot array installed on a reflector. We propose a dipole model of the skeleton-slot elements to calculate its radiation pattern. The prototype antenna has 13 dBi antenna gain, 30% frequency band width and a function of beam tilting, which are sufficient characteristics for the UHF-TV reception.

A thermal model of a TO-5 package in steady state has been derived. The model describes analytically the heat conduction, the heat transfer by free convection and the thermal radiation, taking account of a complicated structure of the package. It has been applied to a study on the negative dynamic resistance by self-heating which is observed in MOSFETs at high current level. The sublinear dependence of the temperature of the cap on the dissipated power in the MOSFETs are explained by the temperature dependence of the heat transfer by free convection.

The single-row single-layer routing is considered for net lists with density5 when backward moves are allowed. A heuristic routing algorithm is given and tested. Comparing with a conventional router, better realizations were found for 38% of randomly generated net lists.

Waveform moment describes one of the characteristics of the given signal wave. Though basic definitions are quite simple, use of waveform moment and extended waveform moment is shown in numerous areas of DSP. Expressions in both time domain and frequency domain are found and using these, criterion for excluding Nyquist filter possibility, evaluation of frequency characteristics for Elliptic filter, method for determining frequency response for not all points etc. are derived. It is shown that analysis using extended waveform moment method becomes simpler than the direct application of known standard methods.

The effects of impurity atoms and energy gap profiles in the optical guiding layers of GaAs-AlGaAs Separate Confinement Hetero (SCH) structure on the threshold current density are theoretically analyzed. Impurity doping in the optical guiding layers is not effective in reducing the threshold current, because impurity atoms induce non-effective current in those layers. The threshold current densities in three types of band gap profiles of the optical guiding layers are examined to find the most profitable structre of the SCH laser. Examined shapes of the profile are step, parabolic and linear types. The lowest threshold current densities calculated in each profile are almost identical if the design parameters such as the thickness of each layer and the alloy ratio are suitably chosen.

Switching characteristics of bistable distributed feedback lasers are analyzed theoretically. The results predict that switch-on speed as well as switch-off speed is improved by a factor of two or more by detuning the Bragg wavelength to shorter wavelength from the wavelength at which the gain is the maximum. This improvement is mainly due to enhancement of the differential gain through the detuning effect.

For grasping the electromagnetic environment, the visualization as a pattern of electromagnetic field distribution is effective. Generally, the electromagnetic field distribution pattern is composed of several fields caused by different electromagnetic wave sources. In this paper, a method of pattern decomposition of overlapped electric field pattern is proposed. This method is based on the least square estimation of intensity of electromagnetic wave sources under the assumption that the location of every source has been given. The estimation formula of electric field intensity of sources is derived. This method is applied to decompose the real patterns measured in semi-anechoic chamber. These experimental results show that the method of pattern decomposition can be used to eliminate or extract the unwanted reflected and scattered field with less error.

A digital system for measurement of angular speed and acceleration or torque for motors is presented, which uses a usual flywheel method with a simple photo-sensor. In our system, an improved type of an inverse-time function generator is especially developed to obtain the accurate angular speed signal from the period of one revolution of the shaft. Despite of the simple form, this system has many advantage in measuring the wide speed range between 128 (or 12.8) and 32768 (or 3276.8) [r/min] with high accuracy of 3 (or 0.3) [r/min] and high acquisition rate (once a revolution). In addition to the digital output for the speed, the analog outputs for the speed and acceleration are also equipped for the torque-speed curve plotting of motors. As a practical application, the torque-speed curves of a two-phase servomotor and a hysteresis synchronous motor are measured.

This paper presents a numerical algorithm to calculate the first and second moments of the first passage times between states on a certain subset, which concern with the key measures of interests of the Markov renewal process with finite states. Since recursive formulas are the important part of the algorithm, it is very well suited to the computation of the moments and is easily programmed. The algorithm makes it possible to compute the key measure of interests on microprocessor even when the model comprised a quite large number of states.

In general, the analysis-synthesis systems are constructed on a linear frequency scale. On the other hand, the frequency resolution of human hearing system have non-linear characteristics. So, it is interesting to study about the analysis-synthesis system on such a non-linear frequency scale like MEL scale. And it is well known that LSP analysis-synthesis method is superior to LPC or PARCOR method in frame rate and quantization characteristics. In this paper, we describe an LSP analysis-synthesis system on MEL frequency scale. At first, we propose the way to obtain LSP parameters on Mel frequency scale (Mel LSP parameters) from the speech signal in linear time domain. Next we propose how to construct the analysis and synthesis filters in linear time domain using the MEL LSP parameters. Furthermore, we combine this system with the ordinary LSP analysis-synthesis system to improve the quality of the synthetic speech. We carried out some experiments to make clear the characteristics of the combined system. The results of tests show that the quality of synthetic speech with the combined system is higher than that with the ordinary LSP system and that with the MEL LSP system on condition that total prediction order is 10. Through the further experiments, we confirm that the synthetic speech quality with the combined system is as good as the that with the standard LSP system at prediction order 12.

This paper presents a queueing system with a load balancing mechanism and an approximate model. We can get the utilization of servers and the distribution ratio from the model. The values agree well the results of simulations.