bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dipole array applicator for hyperthermia
Authors: Terada Noriyoshi , Amemiya Yoshifumi 
Published: July 2007

AbstractHyperthermia (heating therapy) has attracted attention as a possible cancer therapy. Hyperthermia treats an affected area with heat. It is effective alone and its effect is multiplied when combined with other treatments. Many heating devices already proposed limit their heating to the surface; therefore, proposals for devices which can perform deep heating are strongly demanded. This paper proposes an applicator for hyperthermia which provides deep heating by exciting in‐phase dipole elements arranged on a circumference. Theoretical study is conducted to determine numerically various parameters of the proposed applicator and its temperature rise during heating. It is shown that deep heating with less overheating on the surface is possible with this proposed applicator. Furthermore, temperature rise at the tumor area can be expected with heating using a relatively low frequency but overheating and multiple hot‐spots (heating point) as in the case of conventional high‐frequency heating are not produced.
A method for fast synchronization in spread spectrum multiple access communication systems
Authors: Sugiyama Hisayoshi , Amemiya Yoshifumi 
Published: July 2007

AbstractA feature of the spread‐spectrum multiple‐access communication system is that multiple users can simultaneously utilize a common frequency spectrum, and applications to vehicle and satellite communications are anticipated. A problem, however, is that several seconds are required to establish synchronization for the PN code used on the receiving side. To solve this problem, it is proposed that the information for synchronization be acquired using a surface acoustic wave matched filter, but this is difficult in multiple‐access communication owing to the restriction on the number of taps. A new code applicable to the spread‐spectrum multiple‐access communication system with direct spread scheme aimed at the communication of analog information is proposed. It is shown that the surface acoustic wave matched filter, which has fewer taps and is more practical, can be used to drastically decrease the time required for the establishment of synchronization.
The semiconductor pressure transmitter using the diffused piezoresistive diaphragm sensor
Authors: Kozuma Taisaku 
Published: July 2007

AbstractBecause of their high output voltage and convenience of use, pressure sensors composed of strain gages diffused onto semiconductor wafer diaphragms are widely used in research. Here we consider the use of diffused semiconductor strain gages in industrial pressure or differential pressure transmitters for process control. These pressure sensors consist of diffused semiconductor strain gages produced by integrated circuit technology on an elastic silicon wafer diaphragm, and an amplifier. The 24 VDC input voltage and 4‐20 mA output signal may both be carried by the same two wires. This paper describes the investigation of industrial pressure sensor designs and presents experimental data on their characteristics. The specimens tested had a nonlinearity error of +0.02 ∼ +0.2%/25 kg/cm2, a zero point shift of −0.2 ∼ + 0.3%/5 kg/cm2/10 deg C, a temperature‐dependent span variation of +0.4 ∼ −0.8%/5 kg/cm2/10 deg C, and a hysteresis value of −0.05 ∼ + 0.1%/5 ‐ 25 kg/cm2. These results indicate that diaphragms with diffused strain gage sensors are suitable for use in industrial pressure transmitters.
Canonical realization and round‐off noise analysis for combinatorial filters
Authors: Kawarai Shigeyoshi 
Published: July 2007

AbstractRecent developments in memory devices have led to the proposal of a direct method of constructing combinatorial logic filter which uses bit serial operation (i.e., memory and reversible adder are used for bitwise summing of the result of weighted addition). By combinatorial construction it is possible to increase operating speed, simplify the hardware and decrease the power consumption, leading to an efficient digital filter. This paper applies bit serial operation to the canonical construction, leading to a combinatorial filter with memory capacity of 1/2N‐1. Then, bit parallel‐serial operation, which sums up the result of multibit weighted addition, is applied to the canonical construction of the second‐order section, leading to a digital filter with t/I times higher speed than in the past. It is noted that the roundoff noise in the combinatorial filter is independent of the input data, and a noise evaluation model is proposed in which the error can be independently discussed. Using the proposed model, the mean‐square error of the filter output can easily be determined. This paper deals with the drawbacks in the past theory of noise evaluation for the direct construction and performs a noise analysis for the canonical construction. The result is useful in application to LSI design for a high‐speed digital filter.
Decoupling capacitor of substrate bias voltage on dynamic MOS RAM chip
Authors: Taniguchi Makoto , Yamada Michihiro , Kumanoya Masaki , Kobayashi Toshifumi , Nakano Takano 
Published: July 2007

AbstractIn a 64‐Kbit dynamic MOS RAM which has a single 5‐V substrate bias voltage generator, the substrate voltage varies largely with the charge‐discharge process of the bit line as well as of the decoder circuit. Depending on the circuit design, the rate of variation can reach 90%. An example of reducing the sensitivity of a sense amplifier which utilizes a separate memory is shown. Also, in order to reduce the variation of substrate voltage, formation of a decoupling capacitor having a double‐layer polysilicon structure becomes effective. The double layer is underneath the aluminum layer on the chip. Problems associated with this structure are that, due to the alternating current of substrate voltage in dynamic operation, electrons are injected into the substrate, depending on the inversion layer of the MOS capacitor. This results in reduction of memory cell voltage “H”. Moreover, in this paper, we propose a new method of determining the electron diffusion length using the above phenomenon. Also, in order to prevent electron injection from the inversion layer, a P+ layer is replaced. A desirable disturb refresh time for 64 K dynamic RAM is obtained. This RAM has a decoupling capacitance of 600 pF (27% of the total substrate capacitance). In addition to this, variation in the substrate voltage is decreased to about 30%.
Design of fir lowpass matched filter pairs with zero intersymbol interference and quasi equiripple stopband attenuation
Authors: Takebe Tsuyoshi , Higashide Hiroshi , Nishikawa Kiyoshi 
Published: July 2007

AbstractA method is described for designing FIR lowpass filters for receivers and transmitters in data transmission systems. Choosing both filters as a matched pair, the objective is to provide each filter with quasi‐equiripple stopband attenuation and to make the overall impulse response satisfy zero intersymbol interference (zero ISI). The method consists of four steps. First, the ideal overall transfer characteristics are approximated in terms of a Fourier series, and the initial zeros of the characteristics are obtained. Second, one half of the mirror image zeros are used for finding zeros on a unit circle so that the single filter has equiripple stopband characteristics. Third, in the overall transfer function, these stopband zeros are fixed as double zeros. The overall impulse response is successively approximated by changing the mirror image zeros in the passband so that the zero ISI condition is satisfied. Finally, the obtained mirror image zeros are divided into two groups, one is allotted to the transmission filter and the other is to receiving filter so that they form a matched pair. In the zero ISI approximation in the third stage, a good initial response is obtained. Further, since the number of variables is equal to the number of zero ISI conditions, the approximation converges accurately and quickly. As a design example, a filter pair is shown in which both the transmission and receiving filters are 59th orders. The ISI is only 2.2 × 10‐4% compared to 0.4% found in a different design method.
Discriminator with partial response detection of nrz. fsk signals
Authors: Nakamura Yasuhisa , Members Yoichi Saito, Regular 
Published: July 2007

AbstractIn the TDMA subscriber loop radio communication system, large carrier frequency deviation exists in burst signals from subscribers to a base station. A modulation/demodulation technique, which is suitable for the burst transmission with large frequency variation, is studied in this paper. First, problems in the terrestrial TDMA system and clarified and it is shown that the use of conventional FSK‐discriminator detection causes large CNR degradation due to the variation. Next, differential FSK‐Partial Response Detection (DFSK), which can cope with the frequency variation and has a simple structure, is proposed and its principle and structure are described. Furthermore, the intersymbol interference and adjacent channel interference characteristics are evaluated theoretically and the bit error rate (BER) characteristics are evaluated experimentally. As a result, the optimum modulation index and IF‐band reception band path filter are obtained. Finally, the optimum transmission system of DFSK designed for wide‐band Digital Radio Subscriber Loop System using 26‐GHz band is described. DFSK is shown to be a practical and promising modulation/demodulation system for a terrestrial TDMA communication system, on which a large demand is expected in the future.
Graphical analysis of oscillator stability and noise in several kinds of circuits
Authors: Member Susumu Hamaya, Regular 
Published: July 2007

AbstractTo achieve increased output and frequency stability in solid‐state oscillation it is necessary to reduce the oscillator noise. Measures that may be employed to achieve this include operation of a number of oscillators in parallel, external injection locking, self‐injection locked operation or a combination of such measures. The purpose of this paper is to clarify the nature of the mechanism which causes improved stability or improved noise characteristics due to injection‐locked operation and to develop an intuitive grasp of the stability and noise characteristics of such complex oscillator circuits. In the analysis technique we consider oscillators operating above the microwave band using traveling waves. The Rieke diagram of the oscillator is transformed so that the traveling wave analysis can be performed and a graphical presentation is used to show how arbitrary frequency components of noise are outputted. It is clearly shown how the oscillator output signal (angular frequency ω0) interacts parametrically with the noise equivalent input signal (ω0 ‐ ωn) due to the input signal amplitude dependence of the Rieke diagram, producing a noise output signal of angular frequency ω0. We are also able to show on the Rieke diagram how the noise characteristic varies with the magnitude and frequency of the injection signal.
Nonlinear analysis of response characteristics of ganglion cells in the retina
Authors: Fukushima Yoshihisa , Members Masayuki Kimura, Regular , Member Kenichi Hara, Regular 
Published: July 2007

AbstractResearch has been reported in which Wiener's nonlinear system theory is applied in order to analyze the information processing ability of the visual nervous system. As a result, some remarkable results have been presented concerning the response characteristics of certain kinds of cells in the retina. However, to discuss the higher‐order nonlinearity based on such a theory, a large amount of computation is required, and it becomes difficult to give an insight into the physical meanings of the obtained result. For a quantitative investigation of the response characteristics of the ganglion cells, this paper proposes a new nonlinear analysis method based on the physiological findings concerning the basic connections among neurons and their response characteristics in the retina. The method of anlaysis is applied to ganglion cells in the cat retina to demonstrate the effectiveness. The response characteristics of receptive fields of ganglion cells are also examined. Hence, it is seen that a large contribution comes from bipolar cells to X‐type ganglion cells, resulting in an almost‐linear response. The Y‐type ganglion cell receives a large contribution from amarcrine cells, resulting in a remarkable nonlinear response.
The sleeve monopole antenna in a warm plasma
Authors: Morita Yuzuru , Members Shigeru Egashira, Regular 
Published: July 2007

AbstractA sleeve monopole antenna in a warm plasma with length almost the plasma wavelength has been analyzed in the frequency region where electron plasma waves exist. The current distribution and the input impedance have been obtained. When Landau damping is not considered, the current distribution is similar to that for a dipole and oscillates violently near the plasma frequency. It approaches a triangular shape as the frequency is increased. The input impedance varies considerably near the plasma frequency depending on the sleeve length. On the other hand, if Landau damping is taken into account, the amplitude of the oscillatory component of the current distribution becomes extremely small. For the input impedance, the effect of the sleeve beyond 25 times the Debye length can be neglected. This result agreed well with the measured input impedance values. It is found that the sleeve as the external conductor of the coaxial feeder has the effect of reducing the input impedance.
An automatic filter using switched capacitors—performance as an automatic equalizer at low s/n
Authors: Yoshida Yuichi , Murahara Yuji , Kuwabara Hiroshi 
Published: July 2007

AbstractAn automatic filter with an analog transfer characteristic is desirable as a receiver filter for data transmission over a channel in which both the channel distortion and the additive noise are generated and these interferences fluctuate. In this study an automatic filter that is easily integrated and readily controlled digitally is realized with SCF and its capability is demonstrated. As the fundamental configuration, the Laguerre function system is employed and the gradient method by zero crossing spacing is used as the automatic adjustment algorithm. The analog pre‐filter, indispensable in a sampled‐value system, is practically eliminated since the only resistor in the automatic filter is used for this function as well. This is made possible by choosing the switching frequency of SCF sufficiently higher than the baseband. The experiments have been performed for the preset type and for the adaptive type and the symbol error rate has been obtained. It is found that the present type exhibits a performance close to the theoretical value of the optimum filter, and the adaptive type also demonstrates a sufficiently acceptable performance.
Quick‐response phase‐shifter using digital phase‐locked loops
Authors: Iritani Tadamitsu , Satonaka Hisashi , Kinouchi Yohsuke , Ushita Tomiyuki 
Published: July 2007

AbstractThree types of new quick‐response phase‐shifters are proposed using digital phase‐locked loops (DPLL). They use a new method of level‐slicing the sawtooth waveform of PLL's VCO. The response time for a phase shift (0° ∼ 360°) is less than one period of the input frequency, and is faster than that of conventional ones. Moreover, we group these phase shifters into three classes according to the step response of the input frequency in the DPLL. The first‐class phase shifter has the simplest structure, where a quick response to the input frequency change is not expected so much and a stress is put on eliminating the noise in the input. Its phase shift error increases due to VCO waveform distortion if its response is improved. The second‐class phase shifter realizes a quicker response at the quantization error level by linearizing the VCO waveform. Finally, using the time‐optimal DPLL with the fastest settling time, the response time of the third‐class phase shifter can be made less than one period of the input frequency regardless of the input frequency change.
A constructive approach to the analysis of nonlinear resistive circuits based on the fixed point algorithm theory
Authors: Member Yuzo Sumi, Regular , Oishi Shin'Ichi , Takase Tadaaki , Members Kazuo Horiuchi, Regular 
Published: July 2007

AbstractThe existence problem for solution of a nonlinear resistive circuit and the problem of identifying the number of the solutions are classic and basic problems in circuit theory. In their paper “On the application of degree theory to the analysis of resistive nonlinear networks” (Int. J. Cir. Theor. Appl., 5, pp. (1977)), Chua and Wang presented a unified theory for the existence of solutions for nonlinear circuit equations. That is, on the basis of the degree theory the existence of solutions of many nonlinear resistive circuits can be guaranteed in a unified manner by showing that the circuit equations are homotopic to certain odd fields. Their arguments are, however, not constructive. In this paper, an algorithm based on the fixed‐point algorithm theory is presented and it is proved that by this algorithm at least one solution can always be constructed for nonlinear circuit equations whose solutions are guaranteed to exist by Chua and Wang's theorems. Usefulness of the algorithm is also demonstrated by a few examples.
Structural controllability of electromechanical networks
Authors: Suzuki Yoshihiko , Mio Masao 
Published: July 2007

AbstractThis paper discusses structural controllability for non‐strongly connected networks, especially an electromechanical network connected by an energy conversion device. The energy conversion device is nonlinear and all other associated devices are linear. Thus, this paper considers the linearized state equation for studying the structural controllability in the neighborhood of an equilibrium point. Because of the nonlinearity of the energy conversion device, the coefficient matrix of the equation is decomposed into the product of matrices for graph incidence information and resistances and the matrix for element values other than resistances. The sufficient condition for the structural controllability is characterized by using only the first of these matrices. It is shown that the sufficient condition for the structural controllability of the electromechanical network is that its equivalent electrical network graph have no capacitor‐only cutsets and no inductor‐only loops.
On single layer routing with no wires passing between adjacent pins
Authors: Masuda Sumio , Kashiwabara Toshinobu , Fujisawa Toshio 
Published: July 2007

AbstractThis paper examines whether a circuit is realizable on a single‐layer printed wiring board. Linear time algorithms for this problem have been proposed under the constraint that no wiring is permitted below the mounted modules. However, this problem becomes NP‐complete when wiring below the mounted modules is permitted and the number of wires available between adjacent pins of a module is given. This paper presents an algorithm for this problem under the constraint that wiring is permitted under modules but no wires are allowed to pass between adjacent pins. The time complexity of this algorithm is proportional to the total number of pins of the circuit.
Control of the chrominance pattern with the luminance pattern
Authors: Sakata Haruo 
Published: July 2007

AbstractThe visual transmission of information consists of luminance information and chrominance information, which basically are dependent on each other. However, a new visual phenomenon in which chrominance information is controlled by luminance information has been found. It is described as follows.(1) When a stationary luminance noise pattern is superposed on a chrominance spatial sinusoidal pattern (yellow‐blue), the chrominance sinusoidal pattern is deformed. As a result, the light portion appears as yellow and the dark portion as blue. This phenomenon occurs at 2 ± 3 cpd of the luminance noise frequency.(2) A small‐field achromatic sine‐wave pattern enclosed by a yellow‐blue chrominance sine‐wave is perceived as yellowish in the white portion of the achromatic sine‐wave pattern, and as bluish in the black portion (4±6 cpd of the spatial frequency). These phenomena can be explained by lack of or no working of blue cones at the retinal fovea and the influence of the surrounding color on the appearance of color at the fovea.Acknowledgement. Several helpful discussions on this study with each member of the visual psychology group at NHK Broadcasting Science Research Laboratories are gratefully acknowledged. The author also would like to thank Miss Y. Okada and Miss Y. Yamaoka for the evaluation experiments.
Adaptive transform coding of speech using vector quantization
Authors: Moriya Takehiro , Honda Masaaki 
Published: July 2007

AbstractA digital wireless communication and speech packet transmission are two types of communication in which medium‐band (4.8‐9.6 kbps) speech coding for transmission and storage is essential. This paper investigates the minimization of waveform distortion using a waveform coding which is affected little by ambient noise.An adaptive transform coding of speech using vector quantization (ATC‐VQ) is proposed. Two methods are introduced to utilize vector quantization in a frequency domain.
Active RC networks realizing immittance function and their applications
Authors: Fukai Sumio 
Published: July 2007

AbstractThe inductances, FDNRs, etc, in active RC networks are realized as immittance elements. Considering the existence of high‐order elements, a new method of constructing networks can be devised. In this paper, we present active RC networks realizing immittance functions. From fundamental circuits based on unilateral immittance circuits, high‐order networks realizing immittance functions with positive coefficients are derived. Their applications are demonstrated by inverted L‐type circuits. It is shown that the realized networks can be simply constructed and that desired values of the network parameters are easily obtained. It is confirmed by experiment that non‐pole type 5th‐order low‐pass filters constructed with the proposed networks are practical and the circuit sensitivity and dynamic range of the filters are studied.
Design and performance of a small cesium tube
Authors: Kihara Masami 
Published: July 2007

AbstractThe introduction of cesium oscillators as standard clocks in communication networks of the future is expected. It is known that the frequency stability and life of a cesium oscillator mainly depends on the cesium beam tube employed. This paper describes a design method of a cesium tube considering the short‐term frequency stability ± y(T) of the oscillator. The main factors controlling the S/N ratio of the cesium beam tube are considered. Using the figure of merit relating to ± y(T), a method is presented for optimizing the basic parameters (signal current, beam current and half‐amplitude frequency) relating to the Ramsay resonance signal. If the ratio of the beam current to the signal current is constant in the atomic beam tube without an electron multiplier, it is possible to obtain the same S/N ratio as in the conventional cesium‐beam tube with an electron multiplier by increasing the beam current. The figure of merit can be increased by increasing the signal current even if the half‐amplitude frequency is wide. Analysis of the operation of a small atomic beam tube is carried out to determine the optimum arrangement of components in the tube. It is confirmed by manufacturing a prototype beam tube that the figure of merit of 0.64 can be obtained as predicted.