bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvability of model following problem with internal stability
Authors: Yasuda Tutaka
Published: July 2007

This paper presents necessary and sufficient conditions for a compensator to be designed so that the transfer function matrix of the closed‐loop system obtained by adding the compensator to a plant, agrees with that of the given model and so that the closedloop system (the model following system) becomes stable. Also, a method is shown of constructing a stable model following system without going through trial and error. the existing method [5] constructs an internally stable model following system first by constructing a model following system without considering the internal stability, and then by testing whether or not from that, an internally stable model following system can be constructed. Hence, in this method all the model following systems must be constructed, which, at present, is very difficult. the results of this paper permit one to test whether or not an internally stable model following system can be constructed directly from given system parameters. Thus it is better than the existing method [5].
New decoding algorithm for a class of simple iterated codes–its application to decoding algorithm for reed‐muller codes
Authors: Tokiwa Kinichiroh , Kasahara Nasao , Namekawa Toshihiko
Published: July 2007

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.
Analysis of monopole antenna with ground wires
Authors: Taguchi Mitsuo , Egashira Shigeru , Egashira Ryoichi
Published: July 2007

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° downward. 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 wavelength. When the ground wires are 0.2 wavelength long and the angle of inclination is 300 the antenna is matched with a 50‐Ω feed line and the gain becomes 4 dB.
Mechanism of humidity‐sensitive switching in electroformed silver thin films
Authors: Tanaka Koji
Published: July 2007

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 a 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 the OFF states and the breakdown of the conductive filaments also are discussed.
High‐accuracy MOS A/D converter with inherent self‐compensation
Authors: Tsukada Toshiro , Takagi Katsuaki , Nagata Minoru , Kita Yuzo
Published: July 2007

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 MOS 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 a 14‐bit A/D converter. Performance evaluation of the circuits demonstrates that the method proposed here has reduced the linearity error by 3 bits from 8 LSBs to 1 LSB.
Degradation characteristics of connector contact systems with gold/tin and gold/silver interfaces
Authors: Ando Yasuhiro , Kanai Tsuneo , Sakai Yoshikazu
Published: July 2007

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 of such dissimilar systems. the 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.
Improvement of efficiency of N2 laser‐pumped infrared dye lasers through energy transfer excitation
Authors: Muto Shinzo , Nagashima Humihiko , Nakamura Kazuhiro , Ito Chiaki , Inaba Humio
Published: July 2007

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.
Numerical solution for sinewave oscillator circuits by asymptotic method
Authors: Okumura Kohshi , Yasuda Hisashi , Kishima Akira , Takase Kengo
Published: July 2007

This paper proposes a numerical approximation method for analyzing the steady state and the transient state of sinewave 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 as 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.
Multiple scattering in electromagnetic scattering by many perfectly conducting circular cylinders
Authors: Komiyama Akira
Published: July 2007

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 it 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.
Formations‐elliptical scanning electron‐beam cross section for removing unscanned area in high resolution camera tubes
Authors: Kurashige Mitsuhiro
Published: July 2007

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.
Architecture of an image signal processor
Authors: Fukushima Tadashi , Kobayashi Yoshiki , Hirasawa Kohtaroh , Bandoh Tadaaki , Ejiri Masakazu
Published: July 2007

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 10.9 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.
Microcomputer‐based avalanche injection system and determination of distributed area density of traps in SiO2 film
Authors: Haneji Nobuo , Asada Kunihiro , Sugano Takuo
Published: July 2007

The feedback circuit for stabilizing an avalanche 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.
Particle device simulation in Si and GaAs MESFETs
Authors: Tomizawa Masaaki , Yoshii Akira , Yokoyama Kiyoyuki
Published: July 2007

The ordinary continuum model cannot be applied to analysis of submicron device performances 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.
Simplicial fixed points algorithms for finding several solutions of nonlinear circuits
Authors: Takase Tadaaki , Oishi Shin'Ichi , Io Hideaki , Yamamura Kiyotaka
Published: July 2007

The fixed‐point algorithm is a method of obtaining the constructive solution of the system of nonlinear equations. the fixed‐point algorithms can roughly be divided into the differential method and the piecewise‐linear method. This paper adopts the fixed‐point algorithm based on piecewise linearization, which does not require considering the differentiability of the system of nonlinear equations, and shows a method for determining more than one solution of the n‐dimensional system of nonlinear equations. the homotopy defined on 0, ∞ × Rn is used. to trace the solution curve of the homotopy, the special decomposition triangulation of 0, ∞ Rn space is required. By providing a new triangulation of 0, ∞ × 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.
A consideration of time domain analysis of networks containing coupled transmission lines using their wave digital filter representation
Authors: Wakabayashi Hiroyuki , Suzuki Masatoshi , Miki Nobuhiro , Nagai Nobuo
Published: July 2007

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 representations 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.
Adaptive pole placement applicable to nonminimum‐phase systems of unknown order and unknown dead‐time
Authors: Shinnaka Shinji , Suzuki Takashi
Published: July 2007

In most of the existing design methods of discrete‐time adaptive control systems, the conditions are required on the unknown plant, which is the object of control, that the order and the dead‐time are known or the zeros of the plant are stable, which seem 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.
A construction of vector quantizers for noisy channels
Authors: Kumazawa Hiroyuki , Kasahara Masao , Namekawa Toshihiko
Published: July 2007

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 coding problems. This paper reconsiders 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 for noisy channels over the conventional vector quantizer becomes significant for highly correlated sources and longer block length.
An algorithm for resizing polygonal regions and its applications to LSI mask pattern design
Authors: Sato Masao , Tachibana Masayoshi , Ohtsuki Tatsuo
Published: July 2007

In this paper we consider the problem of resizing figures in a digitized XY coordinate plane. the figures are regions closed by line segments parallel to the × 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 propose 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 algorithm 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.
Timing control circuit for Josephson IK RAM
Authors: Yamauchi Yoshiki , Yamamoto Masafumi , Miyahara Kazunori , Ishida Akira
Published: July 2007

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 dc‐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‐μm Pb‐alloy technology was designed and proper operation confirmed by an experimental read access time of 3.3 ns.
Synthesis of linear model‐following systems using measured output feedback
Authors: Yasuda Yutaka
Published: July 2007

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 coincided 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.
Radiation mechanism of perfectly conducting antennas ‐ an interpretation using Nukiyama's vector
Authors: Tokumaru Shinobu
Published: July 2007

A problem inherent in discussing the antenna radiation mechanism is that the electromagnetic energy flux density can not be deterministically defined. the practice has been to interpret the Poynting vector as the flux density vector and to use it to explain the various phenomena. In this paper, as the equivalent of the Poynting vector, the Nukiyama vector derived from the energy theorem is interpreted as the flux density vector. This interpretation is applied to the radiation mechanism of a perfectly conducting antenna, and it is shown that the radiation can be explained as “an exchange of energy between the electromagnetic wave radiated into space and the conductor on which the power is impressed, with the energy exchange taking place as the energy transverses the conductor.” It is also shown that the new concept of locally‐stored energy derived from Nukiyama's vector for use in this exposition is a broad concept which also encompasses the representation of observable stored energy as defined by Rhodes.
Optical waveguide analysis using the fourier transform and its application to intersecting waveguides
Authors: Seino Minoru , Nakajima Hirochika , Daido Yoshimasa , Sawaki Ippei , Asama Kunihiko
Published: July 2007

In analyzing inhomogeneous waveguides, this paper derives an analytical method that is effective even for the radiation mode light. Also, the propagation characteristic of intersecting waveguides is studied by using this method. In this analysis, considering virtual waveguides that include the real waveguide completely, the propagating light is expressed by the Fourier transform with virtual modes set up in the virtual waveguides. Moreover, using the concept of the power flow equation, the Helmholtz equation is transformed into a difference equation of Fourier coefficients, where weak coupling and paraxial rays are assumed.

Applying this method to intersecting waveguides having inhomogeneous index gradients, we study the dependency of the propagation characteristics of the intersecting angle and the index gradient difference. From these results, light propagation in branching waveguides is found for low intersecting angles. This phenomenon is explained successfully by a model which combines TM0and TM1modes. Furthermore, the propagation characteristics of inhomogeneous waveguides are simulated and their dependency on the index gradient is studied.
Analysis of modulation characteristics of semiconductor laser with lateral field coupling control
Authors: Genei Koichi , Ito Hiromasa , Inaba Humio
Published: July 2007

The internal loss modulation of a semiconductor laser has a very rapid response because it depends on the photon lifetime in an optical cavity. This technique is applicable to high‐frequency modulation and generation of short light impulses which could not be possible by means of ordinary current modulation. the present paper describes some results of small‐signal and large‐signal sinusoidal modulation which are obtained by applying a rate equation to a lateral field coupling control (LFCC) semiconductor laser. It is found that modulation at frequencies higher than 10 GHz is possible and that light impulses with 10‐ps half width can be obtained at several GHz. These results are applicable to other lasers with internal loss modulation.
Infrared laser detection by antenna‐coupled point‐contact schottky diodes
Authors: Inoue Narumi , Yasuoka Yoshizumi
Published: July 2007

The responsivity of antenna‐coupled point‐contact Schottky diodes to CO2 laser radiation was studied experimentally. the very clear antenna‐pattern was obtained for the 10.6 μm radiation and agreed with theory based on the traveling wave antenna. the bias voltage dependence of the detected voltage agreed with the results calculated by using measured dI/dV ‐ V and d2I/dV2 ‐ V characteristics. It is seen from this that the fabricated devices respond to the frequency of a CO2 laser as a square‐law detector (resulting from nonlinearity of the I ‐ V characteristic at CO2 laser frequency) and detect the laser signal by rectification due to the nonlinear current‐voltage characteristic.
Circularly polarized printed array antenna composed of end‐fed strip dipoles and slots
Authors: Ito Koichi
Published: July 2007

Recently, many attempts have been made to increase the bandwidth and the gain of circularly polarized antennas constructed on printed circuit boards. In a previous paper, a wide bandwidth was achieved for a circularly polarized array antenna composed of strip dipoles and slots (CP‐PASS), although its actual gain was rather low. In the present paper, the gain of CP‐PASS is enhanced by adopting an end‐fed strip dipole as a strip element, and a basic design procedure and some experimental results of CP‐PASS are shown. First, it is verified by experiments that the end‐fed strip dipole has some advantages; for example, it has a sufficient gain, its crosspolar radiation level is low, and it is easy to control the radiation resistance. Second, an approximate analysis is made for a basic radiating‐element pair for CP‐PASS, and a basic design procedure of CP‐PASS is obtained by applying the analysis. Finally, several CP‐PASS are made and measured, and the design procedure is found to be useful. For a six‐pair CP‐PASS, its actual gain, 3‐dB gain bandwidth, and axial‐ratio bandwidth are about 12 dBi, 11% and 12%, respectively. It is found also that CP‐PASS requires only a slight correction to the element lengths when a reflector is placed. In addition, it is obtained that the gain of CP‐PASS may be increased further.
Synchronous spread‐spectrum multiplex communication system using a modified m‐sequence
Authors: Tanimoto Masayuki , Sumiyoshi Hirotsugu , Komai Mataji
Published: July 2007

Although the conventional spread‐spectrum communication system has the advantage of asynchronous multiple‐access, the number of simultaneously communicable channels is small due to the interchannel interference and the efficiency of frequency utilization is very low. to deal with this problem, this paper proposes a new synchronous spread‐spectrum multiplex communication system employing a modified M‐sequence. the modified M‐sequence is derived by giving an appropriate dc offset to an M‐sequence so that the sidelobe of its autocorrelation function becomes zero. In this system bitshifted modified M‐sequences are used as spreading codes for each channel and the synchronization among them is maintained. Let N be the length of the spreading code. If a bandwidth N times as large as that required for one channel transmission is used, and the product of the band‐limiting characteristics and the power spectral density of the spreading code satisfies Nyquist's first criterion, multiplex transmission of N channels is realized without interchannel interference. It is proved that equally chosen filters for the transmitter and the receiver to realize the transmission bandwidth restriction maximize the SN ratio due to noise in the transmission channel and the value becomes equal to that in the one‐channel transmission. Therefore, the same number of channels as in TDM is achieved with the same SN ratio and the efficiency of frequency utilization is improved greatly. As for synchronization, almost the same bit synchronization error as in TDM is allowed.
A pair of dipole antennas for controlling polarizations
Authors: Okubo Shigeru , Tokumaru Shinobu
Published: July 2007

In maritime satellite communications, the fading of the satellite direct wave due to interference from sea return waves is a serious problem which causes difficulties in the communications. As a result, methods of reducing the effect of sea return waves have recently been investigated. This paper proposes an antenna configuration that permits such fading effects to be reduced by controlling the polarization for waves in the direction of the sea return wave (we call it “the reserved direction”). At the same time, the polarization loss for the satellite direct wave is made small. the present configuration is composed of a pair of dipole antennas with a reflector. Controls of these wave sources (current distributions) enable us to synthesize the polarization in the reserved direction which is in opposite sense of rotation with that of the sea return wave, has the same axis ratio, and whose major axis is orthogonal to that of the sea return wave in the reserved direction. This reduces the fading effects greatly. Furthermore, even when the antenna shows a movement according to the vessel movement, we have adopted a system which corrects electrically the antenna fluctuation resulting in saving the mechanical altitude stabilizing equipment. We describe first the fundamental characteristics of the present antenna configuration. Wave source characteristics for controlling the polarization in the reserved direction for simple examples have been presented, along with the theoretically computed results of the axis ratio and radiation pattern, etc. Finally, the results of model experiments have been presented to support the theoretical considerations.
Characteristics of pitch period and amplitude perturbation quotients for the detection of glottic cancer
Authors: Kasuya Hideki , Kobayashi Yoshihiko , Kobayashi Takao , Kanazawa Akira , Ebihara Satoshi
Published: July 2007

In an attempt to detect glottic cancer patients by voice information, this paper discusses the properties of the perturbation quotient defined on the pitch period and the amplitude sequences obtained from the outertracheal vibration in the sustained utterance of a vowel. Examinations were made for 42 glottic cancer patients and 39 aged normals. As a result, the following observations were made:

the glottic cancer patients beyond T2 in T‐classification can fairly accurately be detected.

Applying the linear discriminant function to the perturbation quotients, the discrimination score between the glottic cancer and the normal is almost equal to that of a specially trained laryngologist, who listened to the same sample voices and determined the existence of hoarseness.

the perturbation quotient is almost independent of the age of a speaker and the kind of vowels spoken.

This paper describes a new algorithm to estimate accurately the pitch period and the amplitude sequences, as well as the evaluation of the discriminating capability of the perturbation quotients, taking into consideration the variations within the same speaker.
A new recursive structure for very high‐Q digital and SC‐CTD filters
Authors: Takahashi Nobuaki , Inomata Kenji , Takebe Tsuyoshi
Published: July 2007

The second‐order recursive fundamental section up to now, has larger coefficient sensitivities of the amplitude at the filter central frequency and the central angular frequency itself. This makes it difficult to realize high‐Q bandpass characteristics. This paper proposes a new structure with a feedback loop containing sampled‐data filter with medium‐Q bandpass filter and a longtime delay element. When a second‐order bandpass filter is used as the feedback filter, the transfer function of the new structure is a pseudo‐second‐order function. Then the approximate relation is derived between Q of the feedback filter and Q of the new structure filter. the validity of the expression is verified by numerical calculations. It is shown also that when realizing a bandpass filter of the same Q, to what extent the new structure is superior to the traditional second‐order structure from the viewpoints of coefficient sensitivity and round‐off noise. the design procedure for the new structure is shown also. In the digital filter, the long‐time delay can be realized by using a register or a memory. In the analog sampled‐data filter, it is realized by a charge‐transfer device. Thus, the new structure can be realized by a digital filter, or by combining switched capacitor circuits and a charge‐transfer device. Finally, an experimental example of a high‐Q filter by the latter method is shown.
Control algorithms for out‐of‐chain routing in a telephone network
Authors: Fukuda Akira
Published: July 2007

When part of a telephone network is congested because a different traffic pattern from that designed is offered, attempts are made to improve the network throughput by utilizing other vacant facilities. One such control method is out‐of‐chain routing, which permits calls which overflow from the final in‐chain route under the existing routing scheme (far to near rotation) to be offered to out‐of‐chain routes. Out‐of‐chain routing is expected to improve the network throughput but, on the contrary, it could degrade the network throughput by increasing the traffic toward the alternate route. Therefore a control algorithm for out‐of‐chain routing becomes necessary. This paper first models the switching machine which affects the network overload performance and clarifies the traffic characteristics of three‐node triangle network model when out‐of‐chain routing is permitted unconditionally. As a result, it is clarified that the algorithm which stops routing to the out‐of‐chain routes with office congestion is important. Also, the algorithm which permits out‐of‐chain routing when there is no trunk congestion on out‐of‐chain routes may decrease the throughput compared with the case of no out‐of‐chain routing. the results presented here are confirmed by computer simulation of a laeger network.
Conducted noise measurements of automotive electrical and electronic devices using artificial network
Authors: Yamamoto Shin , Ozeki Osamu
Published: July 2007

As more and more automotive electronic devices have been employed and the level of sophistication of their functions has tended to increase, the needs for further enhancement of reliability of operation in an electromagnetic environment also have been increasing. This paper discusses laboratory measurement methods of RF conducted noise for automotive electrical and electronic devices. Also described are impedance characteristics with power line of six models of Japanese passenger vehicles, suggesting that the impedance can be characterized in three frequency ranges: 10 Hz to 1 kHz; 1 kHz to several megahertz; and several megahertz to 60 MHz. Characteristics of an artificial network simulated power line of the Japanese passenger vehicles are discussed. This paper proposes measurement methods and systems for conducted emission and susceptibility. the proposed system is functional in the 150 kHz ‐ 60 MHz frequency range. In the emission measurement, a histogram of the noise level produced by EUT in the frequency domain can be measured, whereas in the susceptibility measurement system, malfunction modes with EUT, as well as the level of input to cause the EUT to malfunction, can be characterized.
Structures and characteristics of a neural network model for generating circadian rhythm
Authors: Endo Shuji , Kinouchi Yohsuke , Ushita Tomiyuki
Published: July 2007

The biological subject contains a circadian rhythm, which is considered as an autonomous phenomenon originating from its internal structure. the rhythm is known as a biological activity observed in any creature except for prochordata. In most animals, it is found that the circadian rhythm originates from the nervous system. We have discussed the neural network model based on the functions of the neural system, which generate the circadian rhythm. the aim of this paper is to clarify the network structure of the model and to discuss in detail the characteristics through analysis and simulation. It is shown first that the model is composed of two neural oscillators and a neural network with nonlinear transformation characteristics. Then each of the subnetworks is analyzed, describing their basic behaviors. By computer simulation, the entrainment and the change of period are discussed, comparing the result with that of analysis. Those results are compared further with the actual properties of the circadian rhythms of creatures.
Microstrip antennas having posts for circular polarization
Authors: Tokumaru Shinobu , Fukui Satoru
Published: July 2007

To use circular microstrip antennas as circularly polarized radiators, perturbations such as slits are added to resolve degeneracy in the fundamental modes. In this paper, posts are inserted between the circular strip and the ground plane and the degeneracy is resolved. the theoretical investigations of this new circularly polarized microstrip antenna are discussed. In the derivation of the theoretical equations, the field is expanded in terms of Green's functions corresponding to the circular cavity region terminated by an admittance boundary. Numerical examples are given for the frequency characteristics of the axial ratio and the input impedance and for the post dimensions to resolve the degeneracy. the radiation patterns and gains are shown for this antenna. the theory has been confirmed by model experiments.
Fusion splicing between deposited silica waveguides and optical fibers
Authors: Shimizu Nobuo
Published: July 2007

Along with the development of optical circuit elements, the problem of coupling these elements to optical fibers, light sources and detectors is very important in the further realization of highly efficient malfunction optical transmissions systems. In conjunction with the coupling of optical circuit elements to fiber, this paper reports on fusion splicing using the heat of a CO2 gas laser. the circuit elements employ deposited silica waveguide (DS guide), which is excellent with regard to loss, fabrication precision, stability, etc. For coupling of multimode graded‐index fiber to multimode DS guide the average loss of fusion splices was 0.18 dB. Measurement of the reflected light from the splices confirmed that fusion caused the disappearance of reflections. the average loss of fusion splices between single‐mode fiber and single‐mode DS guide was 0.19 dB. A multiple splice of 10 fibers to 10 multimode DS guides spaced 200 μm apart shows the prospect of realizing high‐density multiple fusion splices.
Analysis of single server preemptive priority queues with a renewal process as high‐priority input stream
Authors: Sumita ShüIchi
Published: July 2007

This paper considers a preemptive priority queueing model with two different kinds of priority calls: the inter‐arrival time distributions of high‐priority call and low‐priority call are a general distribution and an exponential distribution, respectively, where the Laplace‐Stieltjes transforms of a general distribution is meromorphic. Both service time distributions are different exponential ones. the service of a high‐priority call begins even if a low‐priority call is under service. Under these assumptions, the mean time in the system of each call is obtained, using the theory of piecewise‐Markov processes. First, the generating functions of steady‐state probabilities of an imbedded Markov chain are derived. Next, by the rate conservation principle of piecewise‐Markov processes, the relation between steady‐state probabilities at a regeneration point and at any time is derived. the average numbers of calls in the system are computed by these probabilities. Further, applying Little's formula to the average number of calls in the system, the mean times in the system are also computed. to evaluate these discussions, it is determined whether these results agree with those of M1, M2/M1, M2/1 preemptive priority queueing models, when the inter‐arrival time distribution of priority call is exponential. Finally, a numerical example is given.
Comparative study on digital noise suppressors for PCM speech
Authors: Yoshiya Kiyosumi
Published: July 2007

In PCM transmission systems a digital, click‐like noise due to bit errors is added to the demodulated speech. In former reports by the author an effective receiver side noise suppression system (SUNDER) was proposed which provides better error detection ratio and output S/N characteristic than other known error detection methods. the characteristics of the system for PCM speech containing background noise and for various binary codes were also published. the present paper considers a comparative study of the SUNDER and other proposed digital noise suppression systems, based on a computer simulation experiment of the output S/N improvement and other related characteristics in the case of PCM speech (8‐bit folded code, μ = 100 logarithmic companding) under the same error conditions. the results have shown that for error rates in the range of 10−5 to 10−2 the output S/N improvement by the SUNDER system is about 18 dB, which is higher by 8 to 9 dB than that by other systems.
Throughput analysis of window data link control procedures
Authors: Inoue Takeshi , Nakanishi Hikaru , Sanada Hidehiko , Tezuka Yoshikazu
Published: July 2007

This paper presents an analysis method for the maximum throughput of the window‐controlled data link under the effect of the propagation delays. the data link is divided into two submodels, and each stochastic process is analyzed independently and the results are integrated. the calculation by this method is simpler than that by the direct analysis, and highly accurate evaluation can be made for comparatively general frame length distributions. It is shown that this approach provides very good approximation, especially for the throughput efficiency ranging from 0.7 to 1.0. the region satisfying certain throughput value is derived and an effective way of selecting the value of window size is presented.
On the computational complexity of an external pin assignment problem
Authors: Kimoto Tsutomu , Tsukiyama Shuji , Shirakawa Isao , Members Regular
Published: July 2007

This paper analyzes the computational complexity of the external pin assignment problem to determine through which external pins the signals are drawn out from a packaging module such that the external pins are arranged on the periphery of the module. the problem is shown to be NP‐complete if there exist preassigned signals (which are to be drawn out through the specified external pins) and sequences of signals such that the signals of each sequence must be drawn out through a set of external pins located consecutively. the complexity of a branch‐and‐bound algorithm for the problem is also analyzed.
Buffer management schemes for a heterogeneous packet switching system
Authors: Takenaka Toyofumi
Published: July 2007

In a heterogeneous packet switching system which handles two kinds of packets with different nonpreemptive transmission priorities and different average lengths, the stationary distributions for the number of packets in the system are analyzed for share and partition buffer management schemes, using Fabens' formulas for the semi‐Markov process. the overflow characteristics are examined by numerical calculations. As a result, it is clarified that in the case of a partition scheme, when the ordinary packet length is fairly longer than that of the other packets, the overflow probability for ordinary packets is smaller than that for the other packets. In the case of a share scheme, the overflow probability for ordinary and priority packets when the ordinary packet length is several times longer than that of the other packets, is smaller than that when both lengths are equal.
All digital phase‐locked loop with nonlinear multilevel quantized phase comparator
Authors: Zheng Nanning , Mori Shinsaku
Published: July 2007

The PLL has assumed an important role and is widely employed in communication systems. In recent years efforts have been directed toward implementation of PLLs by means of digital circuitry and a large number of digital PLLs (DPLLs) have been reported. the binary quantized DPLL has received particular attention. However, in a first‐order PLL, pull‐in performance and operation in the lock mode have conflicting requirements and, in addition, a steadyphase difference is produced when the input signal has a frequency offset, resulting in unfavorable effects on the communication system. In the past, these problems have been resolved by employing a second‐order loop but, due to the resultant complexity of the loop, this causes several problems, including poor transient response and integrator drift. In this paper we present a new DPLL incorporating a nonlinear multilevel quantized phase comparator (with characteristic τ sgn ψ ‐ ψ). By means of its phase comparator characteristic this loop improves the steady‐state phase error and also affords more rapid transient response as well as other features including excellent jitter suppression within the pull‐in range. Performance characteristics of the proposed loop are determined theoretically and are verified by experiment.