bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parallaxless input‐integrated flat panel display
Authors: Miura Masaki , Syoujima Hiroshi , Fukunaga Yasushi , Kondo Katsumi 
Published: July 2007

AbstractInput‐integrated displays with a tablet and liquid‐crystal display (LCD) have been developed for computers. In the input‐integrated displays, parallax due to the thickness of a glass causes the difference between the positions of a pen and the displayed image.To eliminate the parallax problem, a fiber plate was used for the upper substrate of an LCD instead of a conventional glass plate and the newly developed LCD was evaluated.(1) It was found that when a fiber glass was used for the upper substrate of the LCD and liquid‐crystal material with a polarization characteristic (for example, one with dichromatic coloring matter which has anisotropic characteristics in the absorption of visible light in the long and short axes directions of liquid‐crystal molecules), the parallax observed when a glass plate was used almost disappeared.(2) The relationship among the pen position, glass plate thickness, and dot‐pitch of an LCD for conventional LCDs was obtained. Using the relationship, it was clarified that the disturbance due to the parallax could be eliminated.
Measuring system of A, B, and C photoresist parameters
Authors: Sekiguchi Atsushi , Minami Youichi , Matsuzawa Toshiharu , Takezawa Toru , Miyakawa Hisayuki 
Published: July 2007

AbstractThe concept of parameters A, B, and C of photo resist and outline of measuring theory and an instrument have been reported by Dill et al. in 1975. Since then, parameters A, B, and C have been used in simulation of profile or quality control of photoresist. In practice, however, a dedicated measuring instrument is hardly used and parameters are calculated from transmittance measured with a spectrophotometer instead.Dill et al. used a substrate of matched refractive index, but quartz substrate without matching its refractive index to photoresist usually is employed for convenience reasons. In this paper, experiments have been made to clarify the difference between Dill's authentic method and conventional method using a newly developed instrument (ABC‐Analyzer) and a conventional spectrophotometer.Light of broad band from an Xe‐Hg lamp was filtered through a narrow bandpass filter and exposed to a photoresist‐coated sample. Then temporal change of transmittance was measured and stored in a computer. Parameters A, B, and C were determined automatically according to Dill's model using the transmittance data.Calculated parameters through two different procedures were compared. Parameters A, B, and C obtained by using the developed instrument were lower than those obtained by using a spectrophotometer. The difference comes from the difference in calculation method for transmittance. In other words, the transmittance measured with spectrophotometer is different from that based on Dill's definition.Furthermore, maximum differences in parameters A and B were 5 and 45 percent, respectively, between those obtained from the samples using an unmatched quartz substrate and a refractive index matched substrate. This is caused by multiple interference between reflected light from the photoresist/substrate interface and that from the back side of the substrate. It was confirmed that it is important to minimize this effect in order to improve accuracy in measuring A, B, and C.
Fabrication of silica‐based optical waveguides with smooth side walls by RF‐bias sputtering
Authors: Akiba Kenji , Takegata Norihiko , Kawakami Shojiro , Shiraishi Kazuo 
Published: July 2007

AbstractA detailed discussion of the preparation of a buried silica‐based optical waveguide by sputtering is presented. The morphological evolution of SiO2 deposited on a ridge structure and smoothing the side wall are discussed on the basis of both experimental and computer simulation results. A new method of fabricating silica‐based optical waveguides with smooth side walls by radio‐frequency (rf) sputtering is described. A waveguide of either triangular or trapezium‐shaped cross section is fabricated on a prepared ridge in the substrate by rf sputtering. An analysis of the waveguide thus obtained of a triangular‐shaped cross section is made by the propagating beam method (PBM). The potential for application of the technique to optical waveguides is examined.
Frequency stabilization of NRD waveguide gunn oscillator at 60 GHz
Authors: Suzuki Yoshinori , Kuroki Futoshi , Yoneyama Tsukasa 
Published: July 2007

AbstractFrequency stability of a 60‐GHz nonradiative dielectric (NRD) waveguide InP Gunn diode oscillator has been improved based on the phase‐locked‐loop technique. All the millimeter wave circuit elements needed, including the directional coupler, circulator, and so on, have been fabricated by using the NRD waveguide and a new approach has been introduced for harmonic mixer configuration by combining an NRD waveguide and a laterally shielded coplanar transmission line. By means of this approach, the millimeter wave circuit can be contained in a compact housing of 4 cm × 6 cm in area. The stability of the oscillation frequency of the fabricated Gunn oscillator was 2.1 × 10−10 (13 Hz/60 GHz). Further, the phase noise was kept to a small value of ‐48 dBc/Hz. The present results confirm the applicability of the NRD waveguide in the 60‐GHz band.
Discussions on numerical accuracy of the vector finite element methods using the vector‐shape function
Authors: Ohtaka Masato , Kobayashi Takao 
Published: July 2007

AbstractWith respect to the vector finite element method for analysis of the electromagnetic waveguide, the numerical accuracy and the numerical efficiency are investigated for three types of variational expressions with which spurious‐free vector finite element analyses are possible. For the linear, isotropic, and lossless waveguide, these methods are compared with regard to the physical and mathematical properties and the electromagnetic field construction of the guided mode using vector‐shape functions represented by complete polynomials of identical form. Two of the variational expressions use different‐order shape functions for the two transverse components and the longitudinal component. Four types of computation methods can be constructed by selection of the electromagnetic field components. Another method uses the shape functions with identical orders in four transverse components.Numerical computations have been carried out for various waveguides. From the results of the computations, it is shown that the physical and mathematical properties of the two variational expressions using the three transverse and longitudinal components are equivalent and that the numerical accuracy of the propagation constant of each guided mode depends on the magnitude of the longitudinal field components used in an actual computation method unlike the method using four transverse components. By using the results, optimum selection of computation methods can be realized.
Analysis of characteristics of a čerenkov laser via particle simulation
Authors: Horinouchi Katsuhiko , Sanda Masaki , Takahashi Hiroyuki , Shiozawa Toshiyuki 
Published: July 2007

AbstractUsing a method for computer simulation, called particle simulation, this paper investigates in detail nonlinear characteristics (whose analytical treatment has been difficult to date) for a Cerenkov laser composed of a parallel plate waveguide loaded with a dielectric sheet and a planar relativistic electron beam focused with infinite magnetostatic field. The main results obtained here are summarized as follows. First, the growth of an electromagnetic wave is found to be due to energy transfer from the kinetic energy of an electron beam to the electromagnetic energy. Initially, the amplitude of an electromagnetic wave grows exponentially, and then nonlinearity gradually begins to dominate as electrons composing the electron beam are trapped in the electric field of the electromagnetic wave. In the final stage where most of the electrons are trapped, the amplitude of the electromagnetic wave gets saturated. In the early stage where the wave amplitude grows exponentially, the results obtained from particle simulation agree well with those obtained from linear analysis. In this paper, the efficiency of energy conversion from the electron beam to the electromagnetic wave is also estimated with the use of the energy carried by the electromagnetic wave at saturation.
Catastrophic optical damage of algalnp visible laser diodes under high‐power operation
Authors: Fukushima Takehiro , Furuya Akira , Kito Yasuhiro , Sudo Hisao , Sugano Mami , Tanahashi Toshiyuki 
Published: July 2007

AbstractThe conventional method to evaluate the lifetime of a laser diode for catastrophic optical damage (COD) has some problems. A new method is proposed that can account for these problems. and the lifetime of AlGalnP visible laser diodes is evaluated using the proposed method. A microauger electron spectroscopy (μ‐AES) is used to analyze quantitatively both the mutual diffusion and the native oxide between the coating film and laser crystal. These effects are clarified on the degradation of COD power level.
Complex permittivity measurements of dielectric plates using a dielectric loaded cavity resonator in UHF band
Authors: Yu Jing , Kobayashi Yoshio 
Published: July 2007

AbstractA method is proposed for the measurement of complex permittivity (ϵsand tan δs) of a dielectric plate with 50 × 50 mm2at 1 ∼ 2 GHz. A dielectric loaded cavity resonator in which a high permittivity, low‐loss dielectric rod (a relative permittivity of δrand a loss tangent of tan ϵr) is divided into two and a dielectric plate to be measured is inserted between them. The advantage of the present measurement method lies in the fact that the edge effect at the contact planes of the cavity and the sample can be neglected since the energy is concentrated near the dielectric rod. Actually, various plate samples are measured at 2 GHz and the measurement errors are evaluated. For the conventional plate samples with fluctuations in sample thickness 2t= 1.0 mm and the ambiguity Δ2t= 0.01 mm, the measurement accuracy of ϵsis less than 8 percent for ϵs= 2, 3 percent for ϵs= 5, and 2 percent for ϵs= 10. If the manufacturing process allows Δ2t= 0.003 mm, the measurement accuracy of ϵscan be improved to 3 percent, 1 percent, and 0.7 percent, respectively. Also, the measurement accuracy of tan δ is 30 percent for tan δ = 10−4and 2 percent for tan δs= 10−3. The present method is available in the UHF band for the plate samples in the range of ϵs= 2 ∼ 20, tan δ = 10−3∼ 10−4, and 2t= 0.3 ∼ 2 mm.
Design of bandpass filters using triple‐mode dielectric rod resonators
Authors: Komatsu Shigeru , Kobayashi Yoshio 
Published: July 2007

AbstractMultiply degenerate mode dielectric resonators in which several resonant modes are degenerate in one physical cavity are effective for miniaturizing the bandpass filter (BPF) in the microwave frequencies. In this paper, for a triple‐mode dielectric rod resonator at the resonant frequency of 8.5 GHz at which the TMO1δmode is degenerate with the dual mode EH11δ, an accurate design is carried out. A three‐stage Chebyshev BPF and six‐stage elliptic function BPF are designed using these resonators. The coupling coefficient between the dielectric resonators via a coupling hole is computed by a rigorous electromagnetic field analysis. The validity of the computed results is confirmed by experiment. As a result, in comparison with the BPF using the conventional triple‐mode cylindrical cavity resonators, the filter volume is reduced to one‐fifth.
Lempel‐Ziv‐type high‐speed data compression circuit using content addressable memory
Authors: Satoh Akashi , Niijima Hideto 
Published: July 2007

AbstractData compression technology is valuable both for increasing the recording capacity of storage devices and for stepping up the communication speed of networks. The compression algorithm proposed by Lempel and Ziv in 1977 is widely known to give a high compression ratio for data of various types by eliminating repeat data. The drawback of the algorithm is its low speed, which results from the difficulty of searching for variable length repeat data. Content addressable memory (CAM) is effective for increasing search speed, but it is limited to searching for a fixed‐length datum such as a byte or a word.This paper proposes adding a simple circuit to a CAM, thus allowing it to search for variable‐length data and realizing a very high‐speed data compression circuit.
Low‐voltage, high‐speed, and high‐precision current‐mode sample‐and‐hold circuit
Authors: Sugimoto Yasuhiro , Kakitani Hisao , Tsurumi Hiroyuki 
Published: July 2007

AbstractThe authors investigated the current‐mode sample‐and‐hold circuit with the low‐voltage operation, which can sample and hold the input signal current with a high speed and high precision. The differential amplifier is used as the basic component, and a new circuit configuration is developed where the switches are placed symmetrically at the two input terminals to cancel the clock feedthrough.The signal dependency is minimized by adequately selecting the current relation in the circuit and the element size. For the realization of the concept described above, two kinds of circuits are prepared. One is the circuit where the input signal current is given in the form of two inputs in differential mode, and the other is the single‐phase, single‐input circuit. By analyzing the proposed circuits using the SPICE circuit simulator, the following current‐mode sample‐and‐hold performances are obtained: 20‐MHz sampling, 40‐MHz bandwidth, linearity within 0.1 percent, and 3‐V operation is obtained for the former, and 20‐MHz sampling, 45‐MHz bandwidth, linearity within 0.1 percent, and 3.5‐V operation is obtained for the latter.It is seen also that the high‐precision and high‐frequency characteristics, which have been difficult to be made due to the clock feedthrough problem, can now be realized at the same time in the current‐mode circuit.
Automatic on‐line measurement of ship's attitude by use of servo‐type inclinometers
Authors: Member Seiji Nishifuji , Touya Yuji , Tanaka Shogo 
Published: July 2007

AbstractAn accurate measurement of dynamic ship's attitude is important for not only correcting data obtained with sonars in searching seabed patterns but also controlling the attitude of a high‐quality ship. From this viewpoint, a previously developed automatic measurement system measured the heaving, rolling, and pitching of a ship by processing outputs of four servotype accelerome‐ters appropriately located on the ship. However, this measurement system required excessive computational time for data processing because it adopted both the maximum entropy method and an optimization procedure to seek the unknown heaving, rolling, and pitching parameters. To realize the on‐line measurement of the three signals, this paper proposes a new automatic measurement system using two servotype inclinometers and one accelerometer. This measurement system introduces linear dynamic models and linear observation equations on the three signals and reduces the on‐line measurement of the three signals to the state estimation of the linear dynamic systems. A bank of Kalman filters is used to execute the on‐line state estimation and to overcome changes in parameters in the dynamic models with time. Since the proposed measurement system utilizes the two servotype inclinometers and one servotype accelerometer, the measurement system will cost less than the previously proposed one.
A new 8‐12 conversion channel code and its application to high data‐rate video recording
Authors: Ishii Hirotake , Umemoto Masuo , Nonmember Hidehiko Sawamura , Member Yoshizumi Eto 
Published: July 2007

AbstractShort wavelength recording requires a channel code that has a larger minimum magnetic‐transition interval (Tmin) than the data‐bit interval (Tb). An 8‐12 conversion channel code has been developed in whichTminis 1.33 times longer thanTb. In this code, a maximum of four combinations of 12‐bit channel codes are set for each 8‐bit dataword. The proper channel code is selected by referring to the previous channel code and the tentative next channel code. A word‐inversion scheme can be applied to this conversion channel code, drastically reducing the dc component of the code when the code is used in video‐signal recording. As a result, when recording video signals, the dc component and digital sum variation (DSV) characteristics of the new code are superior to those of the (1, 7)RLL code and similar to those of the NRZ‐ASE code. Simulation showed that the 8‐12 conversion code has superior eye‐pattern and error‐rate characteristics compared to the (1, 7)RLL and NRZ‐ASE codes. A video‐signal recording experiment using the 8‐12 conversion code achieved at a recording rate of 198 Mb/s and a recording density of 5.8 μm2/bit indicates that this code will make HDTV digital video cassette recorders feasible. The experimental average error rate was 7 × 10−5, sufficient for HDTV video recording.
Characteristic analysis and test verification of tapered waveguides with finite wall surface resistance
Authors: Ishihara Fujio 
Published: July 2007

AbstractThe detail behavior of tapered waveguide circuits with finite wall surface resistance used at or close to the cutoff frequency is investigated. The analytical method used is based on a generalized waveguide transmission equation applied to the TE10 mode of a square waveguide with finite inner wall surface resistance. An equation suitable for numerical calculations is derived. Further, in the case of waveguides of finite wall surface resistance, the equivalent characteristic impedance and the propagation constant are also derived. The equations derived herein (imposed to a uniform waveguide) are in agreement with the frequently used approximate equations in the frequency range far from the cutoff. Two types of taper waveguide circuits are devised for uses around the cutoff frequency. The shapes of the measured frequency characteristics of the return losses of these circuits are in agreement with those of the theoretical ones. Further, it is confirmed that if the effective value of the conductivity of the wall surface is taken to be one‐half that of the nominal one, there is good agreement between the theoretical and experimental results.
Improved linear‐approximation of thermoelectric differential equation
Authors: Ogawa Yoshihiko , Kiya Humikazu 
Published: July 2007

AbstractThe differential equation which analyzes the temperature distribution in the thermoelectric device is nonlinear, and we must implement numerical analysis to solve this equation exactly. If we want analytical considerations using the equation, the equation must be transformed into any linear‐approximated differential equation. Before now, we introduced the linearized equation from the exact nonlinear equation under some simple approximation. In this paper, we introduce improved linear‐approximated differential equation under more precise approximation. And analytical results for both linearized methods are compared with the numerical method. As the result, values of temperature distribution, heat‐flow density, and coefficient of performance (COP) of Peltier cooling system obtained by the new linearized method are considerably agreeable with those by the numerical method.
Identification of liquid samples using shear‐horizontal surface acoustic wave sensors
Authors: Kondoh Jun , Shiokawa Showko 
Published: July 2007

AbstractThe shear‐horizontal surface acoustic wave (SH‐SAW) propagating on a piezoelectric crystal is made of a strain wave coupled with a piezoelectric potential due to the piezoelectric effect. Hence, the SH‐SAW can detect not only the effect on the strain but also the phenomena affecting the piezoelectric potential (acousto‐electric interaction). The SH‐type surface acoustic wave on a 36° rotated Y‐cut X‐propagating LiTaO3 is suitable for detection of the electrical properties (relative permittivity and conductivity) of liquid since its large electromechanical coupling coefficient makes the acoustoelectric interaction strong.In this paper, attention is directed to the frequency dependence of the sensor sensitivity for the acoustoelectric interaction. It is proposed to identify the liquid by means of the sensing system made of several SH‐SAW devices with different frequencies. Specifically, eleven kinds of fruit juice and thirteen kinds of whiskey were identified. It is found that highly accurate distinction can be accomplished without selective organic thin films.
Influence of switching pulse on I‐V characteristics in series‐connected josephson junctions
Authors: Suzuki Hideo , Yoshida Akira 
Published: July 2007

AbstractTo evaluate the scattering in the critical currents of Josephson junctions, the current‐voltage characteristic of series‐connected Josephson devices have usually been evaluated. However, it has been found that the measured current‐voltage characteristics and the number of switched junctions of series‐connected Josephson junctions often depend on the measurement conditions, e.g., the wiring feature.The authors assumed that these symptoms occurred because the switching pulses generated when the Josephson junctions were switched propagated through the wires serially connecting the junctions and the external wiring circuits. Hence, multiple reflection occurs at the connecting points and terminating points, resulting in a variation in the current flowing through junctions. In the measurement of the current‐voltage characteristics, one of the terminals is grounded inside or outside of the device while the other terminal is connected to a power supply with high impedance.In this case, when numerous junctions were switched simultaneously, the current‐voltage characteristics depended on the distance between the terminal and grounding point. When the other terminal was terminated with a 50‐ω resistor, the number of junctions which switched simultaneously was small. As a result, it was concluded that the dependence of the current‐voltage characteristics on the measuring methods was due to the multiple reflection of pulses caused when the junction switched.
Millimeter wave mixing in thin‐film YBCO Josephson junctions
Authors: Nozue Takashi , Yasuoka Yoshizumi , Chen Jian , Yamashita Tsutomu 
Published: July 2007

AbstractHarmonic mixing characteristics were examined in a 94‐GHz millimeter wave region at liquid‐nitrogen temperature (77 K) using thin‐film YBa2Cu3O7 ‐ x (YBCO) Josephson junctions created by laser ablation. As a result, a mixing signal (IF output) with a harmonic number (N) of up to 30 was obtained in harmonic mixing using the LO wave as the microwave. The output depended strongly on the power of the LO wave and the Shapiro step spacing induced by the LO wave. It was approximately proportional to N−2.
Improving the reliability of space‐use traveling wave tubes and confirming the improvement
Authors: Mita Nagahisa 
Published: July 2007

AbstractThis study establishes the design method for the high reliability for the space‐use traveling wave tube (TWT) and presents the verification experiment of the high‐reliability performance for the case of TWT to be installed on CS‐3, as an example. Based on the relation between the cathode current density and the lifetime, which is derived from the degradation theory of the coated impregnated cathode, the convergence ratio of the electron gun and the cathode current density are optimized.A method is presented which realizes the long‐life and highly reliable TWT, by the high‐reliability design and the screening based on theory. To verify the high‐reliability design, the wear‐out failure distribution is estimated by the accelerated temperature test; and the failure rate due to the random failure is estimated from the actual in‐orbit data. As a result of analysis of this mixed Weibull distribution, it is shown that the failure rate of 1000 fit, which is set as the design goal, can be achieved for 7 years of planned working period. It is shown also that by employing the high‐reliability design, the failure rate of 1000 fit or less can be achieved even if the working period of 10 years is defined.