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In synthesizing RC filters by simulation of LCR filters, the advantages are simplicity of synthesis and low element sensitivities. Ordinarily, the operational amplifiers used in this synthesis method are all considered to have ideal characteristics which hold only at low frequencies. Researches on the effect of he frequency characteristics of the operational amplifiers on the filter characteristics have been done for Biquad circuits in several cases but none at all for higher-order active RC filters. In this paper, first, a synthesis method different from the conventional method is shown for a filter with finite zeros. Then a method for reducing the effect of the finite GB product on active RC filters is shown by contradicting the unnecessary phase-rotating component of the operational amplifiers with the entire circuit, assuming that all operational amplifiers used in the filter have the same GB product. Furthermore, actual circuits are synthesized and experiments are performed. As a result, the effectiveness of the proposed compensation technique is shown by the fact that the frequency range for possible synthesis is extended. Finally, a synthesis method and experimental results are shown for a filter with all poles. [ABSTRACT FROM AUTHOR]

This paper combines the supplementary variable method and the phase method to analyze the steady-state of GI/Ek/I with finite waiting room. Although there have been many studies made on the queue with finite waiting room, there has not been a study of GI/Ek/I which determines the characteristic quantities and discusses the characteristics by numerical computation. This paper defines firs the residual arrival time as the supplementary variable and derives steady-state basic equations for the joint probability density functions of the variable and the total remaining number of phases in the system. Using Laplace transform, the solutions are represented by the joint probability densities for the remaining number of phases and the zero remaining arrival time. The value of joint probability densities is determined, if the distribution function of arrival interval is given, by solving a system of linear equations by numerical computation. Using that solution, various characteristic quantities are represented such as number of customers in the system, actual waiting period length, distribution of idle period length, loss probability and power. Finally, the analytical result for GI/M/1/N is found to be equal to the known result, and as a numerical example characteristic quantities of GI/E4/1/4* are illustrated, together with the discussion for the characteristics. [ABSTRACT FROM AUTHOR]

Recently, for the improvement of reliability of digital communication systems, various kinds of error-correcting codes are being used. To improve system reliability through the use of more capable error-correcting codes it is extremely important to simplify the decoder construction and to reduce the decoding delay. This paper studies a decoding algorithm for a class of simple iterated codes (SI codes) constructed by simply repeating I times a codeword (called block) in a given code (called subcode). Moreover, this paper discusses the decoding delay when this decoding algorithm is applied to decoding the Reed-Muller codes constructed by the superimposing method. [ABSTRACT FROM AUTHOR]

This paper proposes a technique for designing a large class of two-dimensional recursive digital filters. A mapping technique is used to design weakly causal digital filters. The design is based upon minimization of the sum of squared differences between the desired and actual two-dimensional impulse responses over a finite interval. The filter is designed in terms of a canonic from state-space model. The proposed technique has the advantage of simplicity and is applicable to the design of quarter-plane digital filters as well as symmetric half-plane digital filters. The test of stability for such filters is easy. [ABSTRACT FROM AUTHOR]

Recently a few studies have been made of distributed coupled-line type digital frequency multipliers which multiply the repetition frequency of a square input wave. The transfer functions of an n-section distributed coupled-line constant-resistance network and an n-section distributed-constant bridged-T network have the form of a rational function of order n with respect to delay operator Z-1. We develop our discussion on the basis of this transfer function. The theory is developed for the coefficients of the rational function and the output response in a stationary state can be determined by the coefficients of both the denominator and numerator. The obtained results can be applied to all networks having the transfer functions treated in this paper, but the detailed realization condition for each individual network is not discussed. The experiments and calculations shown in Figs. 4 - 7 are conducted using the distributed coupled-line constant-resistance network as an application example. The network described here can be a digital frequency multiplier for two incident impulse trains, 1111 and 1-11-1. The behaviors of the multiplier in the frequency domain as well as in the time domain are investigated and it is shown that a faster impulse train can be obtained at the output in the time domain by adequately thinning out the discrete frequency components of the incident impulse train. [ABSTRACT FROM AUTHOR]

A monopole antenna with ground wires excited at the terminal between the vertical and several ground wires is analyzed by varying the length of the vertical element, the lengths and numbers of ground wires and their angles of inclination. The characteristics of the structure are analyzed for an antenna with a quarter-wavelength monopole element on a perfectly conducting ground plane. In the numerical analysis the effect of the feeder is neglected and a Hallen-type integral equation with a simplified kernel is used. In the experiment the center conductor of the coaxial feeder is connected to the monopole and the outer conductor is connected to the ground wires. The effect of a sperrtopf, which prevents leakage current from flowing on the outer conductor, is studied. From the analytical results it is found that the gain of the monopole antenna with ground wires does not exceed that of a half-wave dipole even if the length of the monopole is made about a quarter wavelength and the ground wires are directed 60° down-ward. When the antenna is on a perfect ground plane, the directivity strongly depends on the distance between the feed and the conducting plane and becomes maximum when the distance is about 0.3 wave-length. When the ground wires are 0.2 wave-length long and the angle of inclination is 30° the antenna is matched with a 50-ω feed line and the gain becomes 4 dB. [ABSTRACT FROM AUTHOR]

The wave normal directions of magnetospheric VLF/ELF chorus have been determined by using data from the geostationary satellite GEOs 2. They will provide useful information on the emission generation mechanism. [ABSTRACT FROM AUTHOR]

Two perpendicular arrays of optical fibers are combined with a spherical lens and cylindrical lenses to form a 2-dimensional-velocity sensor. Each fiber array picks up spatial frequency components of the object pattern, and the center frequency of the narrowband output signal gives a velocity component of the object parallel to the optical fiber array. Therefore, velocity of the object is determined from center frequencies of the signals from the two fiber arrays. The equivalent filter including the imaging system is derived and its spatial frequency selectivity and accuracy of the measured velocity are clarified. The accuracy can be set to the desired value by properly adjusting the parameter values describing this system. The validity of the present system has been confirmed experimentally. [ABSTRACT FROM AUTHOR]

Electroformed silver thin films exhibit reversible switching in wet air at atmospheric pressure. It was proved that the switching is due to the breakdown and the immediate restoration of conductive silver filaments. The mechanism of the restoration of conductive filaments is dendritic silver growth through electrochemical reactions. Adsorbed water onto the surface of the thin films is essential in the process of the restoration of the conductive filaments, i.e., in the mechanism of the reversible switching. Mechanisms of the conduction at the ON and OFF states and the breakdown of the conductive filaments also are discussed. [ABSTRACT FROM AUTHOR]

Considerable effort has recently been devoted to the development of monolithic, integrated-circuit (IC) analog-to-digital (A/D) converters. However, the accuracy of successive-approximation A/D converters has been limited to 10 bits due to the linewidth variations in the state-of-the-art IC processing. Higher accuracies up to 12 bits have been realized only by trimming passive elements. In this paper, an A/D converter with an inherent (on-chip) 'self-compensation' circuit is proposed which enables high-accuracy analog-to-digital conversion without trimming. The principle and circuit construction of the new A/D converter are described. Fabrication and characterization of an experimental device are also discussed. The circuit described is a successive-approximation MOD A/D converter, in which the input charge stored on a capacitor array is redistributed over the capacitors. The errors in the capacitances are evaluated prior to the conversion step using the array itself as a reference. The correction charge is generated automatically during the redistribution step, referring to the correction data. Charge correction is done simply by applying an appropriate voltage to a correction capacitor which is added to the array. This simple circuit is easy to build using a monolithic IC technology. A 3 μm CMOS IC technology was used to fabricate experimental circuits to build a14-bit A/D converter. Performance evaluation of the circuits demonstrates that the method proposed here has reduced the linearity error by 3 from 8 LSBs to 1 LSB. [ABSTRACT FROM AUTHOR]

A new exposed pole-type planar magnetron system for sputter deposition from ferromagnetic targets is proposed. Because the system uses a washer-shaped target, both magnetic poles are exposed at the target surface. This allows great increase in the tangential magnetic field component at the target surface. We used three targets herein: the new washer-shaped ferromagnetic (Fe), conventional nonmagnetic (al), and ferromagnetic (Fe) targets. The magnetic field distribution over each target was measured as a function of the current through a field confinement solenoid coil. The tangential component of the magnetic flux density over the washer-shaped Fe target was much larger than over the conventional ferromagnetic target, showing clearly the effect of the exposed poles. However, when compared with the nonmagnetic target, the tangential component id still small and the effect of the solenoid coil weak. The tangential component of the magnetic flux density is changed by the vector addition of the horizontal component of the solenoid coil field. [ABSTRACT FROM AUTHOR]

Environmental test results are presented for connector contacts with dissimilar metal interfaces where gold-plated contacts are matched with silver- or tin-plated contacts. Tested card edge connectors were exposed in 20-ppm SO2 atmosphere with three humidity levels and in three field sites during 4.5 years. The results demonstrate that dissimilar metal contact systems show remarkable increase in contact resistance rather than similar base metal contact systems. Particularly, high humidity exposures will cause degradation is induced by the galvanic corrosion of wear debris: connector engagement cycles produce the wear debris of substrate metals under the plating. Even in a contact of such similar metals as gold plating, one factor in the degradation is the galvanic corrosion by the wear debris of substrate metals. [ABSTRACT FROM AUTHOR]

The N2 laser-pumped dye laser is an important coherent light source used very widely in research applications of optical properties of various objects. However, it is difficult to obtain highly efficient laser operation in the near infrared range, This paper considers the operation and development of an energy transfer dye laser (ETDL) and the cascade ETDL operation in the near infrared range with the aim of improving the efficiency of the N2 laser-pumped infrared dye laser. As a result, Nile-Blue-HITC ETDL and Nile-Blue-Cryptocyanine ETDL operating in the range of 700 nm - 900 nm have been realized. Furthermore, in the ternary dye mixture system with addition of Rhodamine-B to these dye mixtures, the cascade ETDL operations also occur efficiently. The high efficiency of the N2 laser-pumped near infrared dye lasers has been realized by means of these ETDLs, and a wide tuning range laser operation has been obtained. [ABSTRACT FROM AUTHOR]

Recently, with the advance of micro-fabrication techniques, extremely many circuits are integrated in a silicon chip. As a result, the power density is increased and the processing of this power density becomes a key to realize a VLSI. As a means to resolve this problem, this paper discusses a method for reducing the power consumption in the entire analog-digital LSI by reusing in the I2L circuit, the current already used in the analog circuit. Several representative analog circuits are studied in this paper and a stacking of the analog circuit and the I2L circuit is investigated. As an example, when an I2L circuit id combined in the constant current source side of the differential amplifier with the signal gain of 36 dB, the noise leakage from the I2L circuit to the output of the differential amplifier is about -14dB (about 2mV). This stacked analog -I2L is applied to an actual integrated circuit. Without losing the function and characteristics of the original integrated circuit the apparent power consumption of the I2L circuit is made zero and the power consumption of the entire integrated circuit is reduced from 65 mW to 34 mW, which is about a 50% reduction. [ABSTRACT FROM AUTHOR]

This paper proposes a numerical approximation method for analyzing the steady state and the transient state of sineware oscillator circuits. Since most oscillator circuits contain active and nonlinear elements (e.g., transistors), and inductive capacitive and by-pass components, their circuit equations generally become high-order nonlinear differential equations. The proposed method uses the Newton method to determine the operating point. The variation (ac component) about the operating point is used a variable for establishing a nonlinear differential equation to be solved by means of the Krylov-Bogolyubov-Mitropolsky asymptotic method. The discrete Fourier transform is then applied repeatedly to obtain the second-order approximation for the periodic solutions. The approximation method for transient solutions is also discussed. Finally, an example of a transistorized CR phase-shift oscillator is used to demonstrate the usefulness of the proposed method. The periodic and transient solutions obtained by the proposed method are compared to those of the Runge-Kutta-Gill method. [ABSTRACT FROM AUTHOR]

This paper presents a polynomial-time algorithm which can determine the multicommodity flows in a planar undirected graph G. It is assumed that G remains planar if an edge is added between each source-sink pair. Given positive and real demand to each source-sink pair, the algorithms determines whether or not there exists a multicommodity flow in G realizing the specified demand, i.e., feasibility, and if it exits, the multicommodity flow is determined. It is shown that by solving the maximum-weight matching problem once for a graph which is a modification of the graph dual to the given graph G, the feasibility is determined, and by solving the problem for 0(kn) times, the multicommodity flows are determined. Consequently, if G has a vertices and k source-sink pairs, the computation time required to determine the feasibility is 0(n² log n), and the time required to determine the k-commodity flow is O(kn³ log n). The memory storage required is 0(kn). It is known that the maximum-flow min-cut theorem exists for the case of planar graph considered in this paper. [ABSTRACT FROM AUTHOR]

For the purpose of extending the useful range of trapped-energy resonators and filters up to the middle band less than a few MHz, the energy trapping of the width-extensional vibrations in a thin piezoelectric strip is studied. Since the width-extensional vibration exhibits a dispersion characteristics of the high-cut type in most piezoelectric materials, the backward-wave energy trapping needs to be applied. As realistic methods, two approaches are discussed. In one of hem, the areas on both sides of the excitation part at the center of the strip are short-circuited by the electrode. In the other method, this portion is made unpolarized. In each approach, the energy trapping of the width-extensional vibration is realized if the electrode in the excitation part is made a partial electrode with its width narrower than the strip width. A clean resonant response with few unwanted modes is obtained. A method for fabrication and experimental results are reported for a ladder filter and a single-mode three-terminal filter. Effectiveness of this device for a filter in the middle band is indicated. [ABSTRACT FROM AUTHOR]

This paper discusses the measurement results obtained with regard to atmospheric attenuation at 35 GHz using a sun trecker. The measurements are intended to provide an understanding of the atmospheric absorption attenuation characteristics of millimeter waves on high-angle propagation paths. We first provide a simple description of the construction and performance of the sun tracker and then discusses the method of measuring atmospheric attenuation by means of solar radio observation. The annual, seasonal and monthly variability of measured atmospheric attenuation at 35 GHz are then clarified based on statistical analysis of measured data covering a period of nearly 5-½ years. Regression analysis is performed on the relationship between the measure atmospheric attenuation and the surface meteorological data. Linear regression expressions are derived with respect to the surface vapor levels, the multiple regression equations are derived for the relationship between the surface vapor content and the oxygen content corresponding to the surface meteorological data. Using those equations, a study is made of the estimation precision that can be achieved in estimating atmospheric attenuation from surface meteorological data. Finally, a comparison is made between the measured attenuation and the calculated attenuations using aerological data in the theoretical equations of Bean et al., which are widely used in Japan. [ABSTRACT FROM AUTHOR]

Multiple scattering phenomena have been analyzed via analysis of scattering by several circular cylinders. However, most of these works treat only the far field for the cases where the cylinder radius is much smaller than the wavelength and the cylinder separation is much larger than the radius. In this paper, the effect of the multiple scattering on the near and far fields is studied when perfectly conducting circular cylinders with radius comparable to the wavelengths are placed at separations comparable to the radii. The analysis is based on the simulated charge method because it provides accurate solutions within a reasonable computational time. The following results have been obtained. The errors of the simulated charge method increase as the cylinder separations are reduced due to the effect of multiple scattering. The multiple scattering effect increases with the number of cylinders and its appears significantly in the scattering cross section. The scattering pattern receives a negligible effect of the cylinders in the shadow region for the incident wave. The direction of the lobe deviates from that expected from the first-order approximation, neglecting the multiple scattering due to the effect of multiple scattering. The near field is affected only by the cylinders within the visible region from the observation point and receives a negligible effect from other cylinders. [ABSTRACT FROM AUTHOR]

A differential coding method regards the transmission line code as a kind of state and assigns the original codeword to each state transition. This method is used widely to regenerate the original codeword as an invariant for the state transition even if there exists state ambiguity during transmission. This paper derives a differential coding theorem as the necessary and sufficient condition for the existence of a differential code on the basis of the mathematical formulation of differential coding problems. According to the theorem, the necessary and sufficient condition for the existence of a differential code is that the set of ambiguity operators should be an irreducible and nonseparable group GG, and that a stationary successive operator, which is antihomomorphism on GO, should exist. The importance of the theorem is demonstrated through the differential coding for the staggered QAM transmission system, which has been considered difficult to code differentially. Since the theorem is derived under some general conditions, it is applicable to a variety of differential coding problems which may appear in the future. [ABSTRACT FROM AUTHOR]

It is proposed that electric charge stored in unscanned areas on the field of a high resolution camera tube can be removed by an electron beam with an elliptic cross section which is formed by a beam-limiting aperture, or by applying vertical rf electric field on the beam, which is called wobbling. These effects have been discussed analytically. The beam-limiting aperture is applicable to a magnetic focusing and deflecting tube in which, however, the beam spot direction differs slightly from point to point on the picture area; it is applicable also to an electrostatic focusing, magnetic deflecting tube which has rather poor resolution but in which the spot direction is independent of the position on the picture area. On the other hand, wobbling is applicable to a magnetic focusing, electrostatic deflecting tube. [ABSTRACT FROM AUTHOR]

We have developed an LSI especially suited to process image signals (Image Signal Processor (ISP)). It can process signals of a gray-scale image having 256 levels as rapidly as TV images are scanned. The device features a kernel size which can easily be extended by either of two methods. The extension method adds ISPs like building blocks. For example, using four ISPS, a 4 × 4 spatial convolution for reconstruction of a gray-scale image composed of 256 × 256 pixels takes 1.9 ms; the second method adopts our newly proposed image scanning system, the stick scanning system. This enables one ISP to execute a 4 × 4 spatial convolution. In addition, various image processing operations can be done by changing the contents of the programmable control registers within the ISP. Our ISP is fabricated using 3 µm CMOS technology and comprises about 61,000 transistors. The chip is 7.72 × 8.64 mm in size and is mounted in a 64-pin DIP. [ABSTRACT FROM AUTHOR]

Scaling down of solid state devices is indispensable for large-scale integration of circuits. Understanding the characteristic tendency and the limitation of the scaling down provides a useful guideline in recent scaling-down efforts. This paper discusses scaling down of bipolar transistors, especially the I²L, for which little has been reported. The collector dimension of the I²L is chosen as the scale-down parameter. Important characteristics such as the current gain, capacitance and delay time are studied by similarly reducing the device with an identical shape from 5 µm and 0.5 µm. In the analysis, the bandgap narrowing effect and the Auger recombination are considered and the two-dimensional computer simulation program CADDET-B is used. It is expected that the minimum delay time is reduced to about 200 ps and the power dissipation-delay time product is improved to about 3 fJ when the collector dimension is scaled down to 0.5 µm. [ABSTRACT FROM AUTHOR]

The feedback circuit for stabilizing an avalance electron injection current is controlled digitally, and its algorithm has been developed. The injection current can reach within 1% of the target value in a few minutes. The C-V characteristics are measured during measurement of the injection current, and the data are stored on a mini-floppy disk. A new method has been proposed for evaluating the area density of traps, in which a continuous distribution of the cross section has been assumed; reliability of the result is also estimated. It is noted that the cross section and the area density of types cannot be determined simultaneously, and hence the resolution must be predecided according to the purpose of the experiment. [ABSTRACT FROM AUTHOR]

The ordinary continuum model cannot be applied to analysis of submicron device performance because carriers are in non-equilibrium state. This difficulty has been overcome by particle simulations applied to analysis of Si and GaAs MESFET's. The effect of the velocity overshoot on the device characteristics has been found. The continuum model is applicable to Si devices up to gate length 0.1 µm. On the other hand, the nonequilibrium effect of the carriers becomes remarkable in GaAs devices when the gate length is 1.0 µm; in such a case high-speed operation is expected because the carrier velocity is not restricted to its saturation value. [ABSTRACT FROM AUTHOR]

An algorithms for CAD simulations model is discussed for an I²L circuit important for a bipolar analog-digital hybrid LSI. A versatile modeling method is proposed here in which variation of the planar pattern of the I²L circuit is included. In this method the I²L, device is divided into the injector, base electrode, collector and base termination. Each section is modeled by lumped elements consisting of translators, diodes and resistors. The model parameters are expressed in terms of the main current density and main carrier concentration density of the I²L device. From the model, the terminal current and the carrier transit time can be related to the device shape. The terminal voltage dependence of the terminal current and the terminal current dependence of the gain bandwidth product as simulated by this method agreed within 10% with the measured value in the practical range (injector current 1 - 100 µA). As an example of the application of this method to the I²L circuit, the injector current level dependence of the delay time of the 5-stage ring oscillator and the usable current range vs. the input frequency of the 10-stage counter are calculated and the simulation values agreed with the measured data within 10%. [ABSTRACT FROM AUTHOR]

With the progress of microelectronics technology, the amount of design for a variety of LSI's is increasing rapidly. To make the design and production of such LSI' easier and less costly, a gate array LSI is used extensively. This paper describes a global router for gate array LSI's which is incorporated into our layout system. This router is used to generate for each net an interconnection pattern consisting of channel segments in such a unified way that all interrelated interconnection requirements are taken into account at once. A main objective of the router is not only to minimize the maximum of the local wiring densities, but also to distribute all the interconnection requirements over channels evenly to attain 100% interconnection within a limited area. [ABSTRACT FROM AUTHOR]

Problems occur in the automatic routing for a gate array LSI. These include the logically equivalent terminals to be used for a net to be connected to any one of such terminals, and the vertical track of feed-through cell to be used for a net assigned to the feed-through cell. Since the routing area in such as LSI chip is predetermined, these problems are important in attaining 100% interconnection in each horizontal channel. This paper describes a heuristic algorithm for these problems, and experimental results of the algorithm are also shown to reveal its performance. [ABSTRACT FROM AUTHOR]

The fixed-point algorithm is a method of obtaining the constructive solution of the system of nonlinear equations. The fixed-point algorithm can roughly be divided into the differential method and the piece-wise-point algorithm based on piecewise linearization, which does not require considering the differentiability of the system of nonlinear equations, and shows a methods for a determining more than one solution of the n-dimensional system of nonlinear equations. The homotopy defined on [0, ∞) x Rn is used. To trace the solution curve of the homotopy, the special decomposition triangulation of (0, ∞) x Rn space in required. By providing a new triangulation of (0, ∞) x Rn for Merrill's and Eaves-Saigal's methods which are typical and based on piecewise linearization, those methods are extended from the methods of obtaining a single solution to the methods of obtaining more than one solution. [ABSTRACT FROM AUTHOR]

With increased wire density of integrated circuits and with increased speed of signal, crosstalks due to couplings of wires and wave distortions due to impedance mismatches have become a problem. For the transient analysis of these signals, using the wave digital filter representation of the wires, simulation methods consider them as coupled transmission lines. However, the existing methods construct a digital model depending on the load of the circuits to be analyzed. This paper represents the loss-less coupled lines of the circuit to be analyzed by equivalent circuits using ideal transformer interconnections and uncoupled transmission lines. Then its power supply and load, its ideal transformer interconnections and its uncoupled transmission lines are modeled individually by digital filter models thus representing the entire circuit with a wave digital filter. Also, digital models are presented for the cases when coupled transmission lines contain lumped parameter elements and branchings. Furthermore, it is shown that lossy symmetrical coupled lines can be represented by equivalent circuits using ideal transformer interconnections and lossy uncoupled lines, and their wave digital filter representation are given. Finally, a wave digital filter representation of a network containing lossy symmetrical coupled lines is given. It is used as a model for wirings on a GaAs substrate, and examples of its transient response analyses are given. [ABSTRACT FROM AUTHOR]

The most of the existing design methods of discrete-time adaptive control systems, the conditions are required on the unknown plant, which is the project of control, that the order and the dead-time are known or the zeros of the plant are stable, which seems to be rather impractical requirements. This paper discusses a design method of the adaptive control system which does not require such conditions on the unknown plant but the upper bound of the order of the plant. The proposed design method is for the adaptive pole placement systems based on the indirect method in the pole placement systems. The adaptive processing in regard to the unknown order becomes especially important. An effective recursive procedure for this problem is presented, taking the finite word-length of the controller into consideration. With this processing function, the proposed method exhibits a high robustness against variations in order, dead-time and zeros, which may be caused by the variations of the plant parameters. A numerical example is shown for the case when the proposed method is applied to the plant with unknown order and dead-time and with unstable zeros and poles. [ABSTRACT FROM AUTHOR]

This paper presents on interactive fuzzy decisionmaking method for the solution of multiobjective nonlinear programming problems. Considering the imprecise nature of the decision maker's judgments, we assume that for each of the objective functions, he has fuzzy goals expressed in words such as "x should be somewhat larger than a," "y should be in the vicinity of c." To quantify the fuzzy goals of the DM by eliciting the corresponding membership functions, we propose five types of membership functions; linear, exponential, hyperbolic, hyperbolic inverse and piecewise-linear functions. Through the use of five types of membership functions, the fuzzy of imprecise goals of the decision maker are quantified. Then by selecting one of the three possible fuzzy strategies, the compromise solution of the decision maker can be derived from among (local) Pareto optimal solutions. On the basis of the proposed method, a time-sharing computer programs is written in FORTRAN and an illustrative numerical example is demonstrated together with the computer outputs. [ABSTRACT FROM AUTHOR]

Recently, vector quantization has become noted as a highly efficient coding method of image and voice data. So far, many of the highly efficient coding problems, or service coding problems, have been studied separately from channel vector quantization jointly optimizing source coding and channel coding, and proposes a new vector quantizer for noisy channels. Vector quantizers for binary symmetric channels are designed for memoryless Gaussian source, Gauss-Markov source and the real images, and are compared with the conventional vector quantizer which does not take account of channel errors. As a result, it is shown that the performance of the proposed vector quantizer is improved without adding the redundancy for error correction, and the improvement of the performance of the proposed vector quantizer becomes significant for highly correlated sources and longer block length. [ABSTRACT FROM AUTHOR]

Until now, the only global algorithm distribution map of atmospheric noise in high-frequency band was the one published in 1963 by CCIR, based on the observations at 16 sites in the world. However, the map is based on a small number of observation points, and has a problem in accuracy. This paper derives a global distribution map of atmospheric noise based on the global distribution of lightening discharge obtained by satellite. Assuming the average spectrum of the lightning discharge, the map is derived by calculating the ionospheric propagation loss. By this method, the ration in the atmospheric noise of the component by local lightning can be determined, leading to a better understanding of the atmospheric noise characteristics. By comparing the noise intensity obtained by this method with the value by CCIR and the long-term observation at various sites in the world, it is seem that the value by the proposed method as closer to the value actually measure them the one by CCIR, [ABSTRACT FROM AUTHOR]

The quadriphase PSK system is thought to show the highest spectrum efficiency among M-ary PSK systems for mobile communication purposes and is a noted digital radio system. The diversity effect of the QDPSK system using differential detection has been analyzed approximately. However, since no exact analysis has been done, approximation accuracy has not been clarified. This paper first compares the exact analytical value under cochannel interference and the approximate formula. As a result, it is shown by the method of least squares that the error rate is approximated very closely in precision with a simple formula. Analysis of multipath interference, which simulates frequency selective fading, is carried and the performance difference, which simulates frequency selective fading, is carried and the performance difference from that under cochannel interference is discussed. The diversity effect for multipath interference is lessened slightly compared with cochannel interference. It is also indicated that when the average power of a first-coming wave is nearly equal to that of a delaying wave (often the case in multipath interference) and the error rate is degraded, the diversity effect cannot be expected practically. Finally, the need for a technique to alleviate degradation caused by this difficult-to-control propagation characteristics is mentioned. [ABSTRACT FROM AUTHOR]

Examines the effect of an interfering second target on an amplitude-comparison monopulse radar system. Block diagram; Harmonic balance method; Use of nonlinear ordinary differential equations; Ratio of the main target echo intensity to the interfering target echo intensity.

The problem of coupling between the transmission line and the external electromagnetic waves is analyzed more easily and more effectively if it is treated via transmission line theory if the cross section of the transmission line is much smaller than the wavelength and the principal mode of the induced current in TEM. This paper derives the transmission line equations by which the induced current is excited by the electric field components in the transmission direction and between the lines among the electromagnetic field components. The relation with the conventional theory, physical meanings and the equivalent circuits are discussed. In the experiment in which a plane wave is used as the external electromagnetic field, the results agree well with the present theory is confirmed if the transmission line cross section is extremely small. Further, a compensation method is discussed for the transmission line height for which the principal mode is considered TEM. The theoretical accuracy is shown and the fact that the line width restricts the range of applicability of this theory is confirmed experimentally. [ABSTRACT FROM AUTHOR]

Analog basic amplifier ICs (e.g., differential amplifiers, parallel feedback amplifiers, gain control amplifiers) and equalizing amplifier Ics for repeater circuits of high-capacity optical transmission systems are designed using high-speed bipolar technology (e.g., SST-2). Particular consideration is given to reduction of base resistance, optimization of current density and pattern layout and improving breakdown voltage in applying this technology to analog circuits. Moreover, a peaking technique is applied to wideband amplifiers and a gain control amplifier is constructed which has wide linearity and can be directly connected to other differential circuits because of its constant dc level. For a differential amplifier with peaking, a gain of 15 dB and bandwidth of 1.4 GHz are realized. Expansion of bandwidth by peaking is also applied for the gain control amplifier and a gain of 28 dB, bandwidth of 630 MHz and a variable gain range of 30 dB are obtained. In addition, an equalizing amplifier with transimpedance of 70 ∼ 90 dB and bandwidth of 410 ∼ 620 MH is constructed. Thus, it is evident that integrated repeater circuits for use in high-capacity optical transmission systems can be realized. [ABSTRACT FROM AUTHOR]

In this paper we consider the problem of resizing figures in a digitized XY coordinate plane. The figures are regions closed by line segment parallel to the X or Y axis or line segments at 45° angles to the axes. By resizing we mean that, given the closed regions and a change width, we expand or contract the input regions by the change width. After first proving some theorems on resizing, we response an algorithm solving the problem in running time 0 (n log n), where n is the number of vertices in the regions. For particular applications we consider examples using the algorithms for verifying compliance with design rules for the smallest feature size and spacing in a mask pattern, and also the compensation for characteristic machine error in pattern generators, apertures, etc. [ABSTRACT FROM AUTHOR]

The deflection-modulated EBS amplifier operating at microwave frequents requires a deflector working effectively in the frequency band. The relation between the structure of a meander line and its deflection sensitivity, frequency response, and a new type of the support were investigated; thus a deflector for a 4-GHz deflection-modulated EBS amplifier was manufactured. A formula has been derived for the deflection, and it is found that the deflection sensitivity is maximized at a certain ration of the finger gap to the finger pitch of the meander line. When this ratio is increased, the variation of the deflection sensitivity over a given frequency band is increased. We proposed a quarter-wave strip line to support the meander line; it is confirmed experimentally that its quality is almost equivalent to the conventional ceramic spacer. [ABSTRACT FROM AUTHOR]

Toward realization of a fully decoded random access memory (RAM) with Josephson devices, a method of designing and constructing the important timing control circuit employing de-powered loop logic is described. In order to obtain high speed and stable read/write operation, an on-chip timing control circuit for the nondestructive RAMs including decoder, XY-driver and readout data-bus employing loop logic is investigated. Positive and negative transition-edge-triggered single-shot pulse generators (POS,NOS) are newly designed for generating the timing signal pulses and the latter are appropriately delayed using the current steering time, thereby providing a very simple, fast and stable timing control circuit. The timing control circuit for a 1K RAM employing 5-&micro'm Pb-alloy technology was designed and proper operation confirmed by an experimental read access time of 3.3 ns. [ABSTRACT FROM AUTHOR]

In a previous paper we presented procedures of analyzing causality between a time series based on information theory and information flow between time series based on a concept of directed transinformation, which is an information quantity with a direction. In principle, the directed transinformation is defined based on joint probability density between time series. As the length of the time series becomes larger, however, the volume of computation needed also increased exponentially. In this paper, we will discuss efficient computation algorithms. First, we assume Gaussian properties with the time series to present the "correlation function method" as a means of computing of the directed transinformation from correlation function. Second, we present a "linear production model method" in which the information quantity is computed by means of impulse response of a linear production model of the time series. Also, we proved that the linear production model can easily be composed by auto-regression if the time series is steady. Finally, we discussed the validity of time-series analysis based on the directed transinformation through analysis of an artificially produced simulated series. We have concluded that the proposed computation method can provide correct analysis even if the causality of the time series can not be analyzed correctly based on the correlation function. [ABSTRACT FROM AUTHOR]

In the discussion of the two-class feature extraction problem in pattern recognition, Malina [7] proposed recently a new criterion for overcoming the defects of Fisher's criterion. The discussion in this paper focuses on the effectiveness of Malina's criterion and at the same time points out the problem in his feature extraction method, indicating how to avoid the difficulties. First, no clear definition is made in Malina's method for the coordinate system in the feature space, and the coordinate system used is not optimal. Second, the eigenvalue problem must be solved including the solution of inverse matrix in order to determine the feature axis. For the first problem, this paper points out that the coordinate axis di and dj in the coordinate system in Malina's method satisfies diT<∑dj = 0, where Σ is the sum of covariance matrices in the class. Then the optimal coordinate system from that viewpoint is given. For the second problem, the inverse matrix is eliminated by performing a certain transformation (A-1 transformation) to the coordinate system of the original pattern space. The validity of A-1 transformation is shown by the invariance of the distances among classes, and it is shown that the above optimal coordinate system under A-1 transformation is the optimal orthogonal coordinate system satisfying diTdj = 0, i ≠ j. Finally, Malina's criterion is extended to the multiclass case and the problems are discussed. [ABSTRACT FROM AUTHOR]

This paper assumes a situation where the state of a plant cannot be measured directly, and discusses the problem to construct the internally stable model-following linear system without using a state observer. The problem consists in constructing a compensator (dynamic compensator plus feedback) for the plant so that the transfer function matrix of the obtained closed-loop coincides with that of the model, and the closed-loop system (the model-following system) is internally stable. This paper shows the necessary and sufficient condition for the problem to be solvable, using a geometric approach, and a construction method is presented for the stable model-following system without using an observer. In contrast to the existing methods, the construction method proposed by this paper does not require any additional condition, and can construct the stable model-following system with the given parameters without repeating the trial-and-error procedures. [ABSTRACT FROM AUTHOR]

In the usual switched-capacitor filter (SCF), all the switches connected to a node are simultaneously on or off. Thus, every node voltage in the SC circuit changes in synchronization only to in-phase or out-phase clock, and has a very simple representation by RC equivalent circuit. This paper derives first the RC equivalent circuits for the basic SC circuits, and presents a method of simulation for active or passive RC circuit using an SC circuit, based on the obtained result. Finally, it is verified by several experiments that the SC circuit constructed by the proposed method operates as the theory predicts. [ABSTRACT FROM AUTHOR]

After examining the conventional quasi-stereophonic system, this paper presents the bandwidth division system and the phase shift system as two new types of quasi-stereophonic systems. These two new systems are based on the understanding that "if the correlation coefficient of a two-channel acoustic signal is zero (and independent), the sensation of acoustic spreading is a maximum." It is shown that the correlation coefficient of the two-channel acoustic signals obtained by means of these systems approaches 0. In addition, using a computer simulation of the quasi-stereophonic system of frequency-division type, psychological tests were conducted. The tests showed that differences in sound image quality were principally due to sound image broadening sensations and distance sensations, and that those characteristics correspond physically to the absolute value of the correlation coefficient itself. Further, if the correlation coefficient is zero, the sound image is perceived to be broadened to about the extent of the speaker separation, thus verifying the effectiveness of the new broadening sensation control system. [ABSTRACT FROM AUTHOR]

A shaping filter for a stationary stochastic process can be viewed as the open-circuit voltage transfer function of a resistant-terminated reactance 2-port. Further, Levinson's theory regarding spectral analysis (AR analysis) based on the autoregression model of a stationary stochastic process is equivalent to Ricca's theorem in network theory. Using these facts, from the digital lattice filter which is developed from the AR analysis, we can determine the impulse response of the inverse of the reflection coefficient at the output of the resistance-terminated reactance 2-port corresponding to the stationary stochastic process which is analyzed. In this paper we present a technique in which an AR analysis is performed on an autoregressive, moving average process (ARMA process), the impulse response is approximated by a rational function as described above and, by determining the open-circuit voltage transfer function, the ARMA coefficients are derived. Also, we present two different regression methods for determining the rational function approximations to the impulse response. In general, there is no guarantee that the rational function approximations determined by these methods will be physically realizable transfer functions, but it has been verified by modeling tests that, for an ARMA process of finite degree, by this technique we can determine ARMA coefficients which are better than those obtained by AR analysis to approximate the power spectrum. [ABSTRACT FROM AUTHOR]

This paper proposes a method of constructing an RC active network to realize a voltage transfer function matrix without using an integrator. The method is based on the fact that an m-input system of multi-variable controllable canonical form can be decomposed into m subsystems of controllable canonical form using state feedback and input transformation. The required m-input p-output voltage transfer function matrix is constructed using m passive RC networks and (m + p) summers. The network has the following structure. The capacitor edge voltage of the passive RC network is taken out as the state variable, and the state differential equation is realized by the feedback through the input-side summers. The output equation is realized by the feedforward through the input-side summers. The output equation is realized by the feedforward through the output-side summers. The feature of the proposed method is that it is applicable to any proper rational transfer function matrix of any size, not only of the square form. Another feature is that the transfer function matrix can be realized with a fewer number of active elements. [ABSTRACT FROM AUTHOR]

This paper presents a new method of analysis with numerical results for plane-wave scattering by a layer with inhomogeneous permittivity ε (x) and permeability µ (x). The analysis is based on the following idea (1) we construct a periodic structure, an iteration of the given layer and apply Maxwell's equation for this structure; (2) the electromagnetic fields in this periodic structure are expanded into Fourier series, and the obtained characteristic equation is transformed into an eigenvalue equation; (3) the electromagnetic field in the original inhomogeneous layer is expanded by the solutions of the eigenvalue equation, and the reflected and the transmitted waves are computed by using the boundary conditions. We call this method the Fourier series expansion method (FEM). When the differential equation obtained in the first step of FEM contains dεp(x)/dx (or dµp(x)/dx), Hill's matrix method cannot be applied for the profile for which d²εp(x)/dx² (or d²µp(x)/dx²) is discontinuous. By contrast, FEM in this paper can be applied even if εp(x) (or µp(x)) is continuous, dεp(x)/dx (or dµp(x)/dx) is discontinuous. Even if ε(x) (or µ(x)) of the original inhomogeneous layer is discontinuous we can always construct a periodic structure with continuous ε(x) (or µ(x)), so that FEM can be applied. By numerical analysis, the usefulness of the method is evaluated from the viewpoint of the accuracy of the solution vs. the number of terms in the expansion of the comparison with already reported results. As an example of application, reflectivity is computed for the concrete layer with inhomogeneous permittivity and permeability containing magnetic particles. [ABSTRACT FROM AUTHOR]

This paper proposes &Rtilde;(t), an approximation for the auto-covariance function of virtual waiting time in an M/G/1. Calculation by &Rtilde;(t) is much easier and faster than the exact formula R(t). By the use of this approximation, not only the computation for arbitrary model becomes possible, but also the computation time can be reduced below 10-3 time even for the model which can be calculated by the exact formula, such as M/M/1. Comparisons between &Rtilde;(t) and R(t) for several models show that &Rtilde;(t) approximates R(t) closely enough for practical use. We have applied &Rtilde;(t) to the accuracy estimation of waiting time measurement by test calls (test call method) and obtained several important results for waiting time measurement. They are: i) the accuracy is improved as the interval of test calls is set shorter, but is hardly improved even if the interval is set shorter than ten times the mean waiting time (saturation characteristic); ii) better measurement accuracy is obtained by the test call method if the interval of test calls is properly set than by the real call method; and iii) the coefficient of variation of service time distribution greatly affects the measurement accuracy. [ABSTRACT FROM AUTHOR]