bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel waveguide bandpass filter with multiple attenuation poles using four‐armed square‐loop FSSs
Authors: Ohira Masataka , Deguchi Hiroyuki , Tsuji Mikio , Shigesawa Hiroshi 
Published: March 2007

AbstractThis paper presents a waveguide filter loaded with frequency selective surfaces (FSS) that can realize multiple attenuation poles. As the FSS resonant element, a square‐loop FSS with arms is proposed. The authors have studied the design of the shape of the resonant element for the FSS by using the genetic algorithm (GA). There have been problems, namely, that the shape obtained by GA is complex and that the optimization design by GA requires a considerable amount of time. In this paper, these problems are eliminated by means of a square‐loop FSS with arms. The proposed resonant element has a resonance (full transmission) at the center frequency while it has antiresonances (full reflection) on both sides. By means of these antiresonances, attenuation poles can be created. The resonant frequencies can easily be controlled by adjusting the element shape. As an example, a three‐stage waveguide filter loaded with FSSs with a total of six attenuation poles in the X band is designed. By comparison of the numerical results and the experimental results, effectiveness of the proposed shape is verified. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 26–33, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20305
An expression of high‐frequency characteristics on a high‐density multilayer wiring board using an LC ladder network as a unit segment
Authors: Ishikawa Ryo , Imai Norio , Honjo Kazuhiko 
Published: March 2007

AbstractThis paper presents a method of expressing a high‐speed signal transmission line connecting the LSIs in a high‐density multilayer wiring board in terms of cascaded connections of LC ladder networks. For signal transmission with a fundamental frequency beyond 1 GHz, the signal transmission lines in a multilayer board are treated as distributed transmission lines. However, there exist many scattering elements such as vias for interlayer connection in the multilayer board that disturb the transmission characteristic. Transmission characteristics affected by these elements are analyzed by electromagnetic field simulation in general. However, the simulation requires a lot of simulation time and computer resources. In order to simplify the simulation, the signal line structures in the board are constructed with combinations of several segments. Moreover, each unit segment is expressed in terms of an LC ladder network so that an analysis based on the lumped elements can be carried out within a short time. This paper describes a technique for deriving the L and C values of the ladder equivalent circuits for various unit segments such as passive components and transmission lines. By comparison with the electromagnetic field analysis and measurement, the usefulness of the method is demonstrated. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 18–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20317
Highly reliable InP‐based HBTs with a ledge structure operating at high current density
Authors: Fukai Yoshino K. , Kurishima Kenji , Ida Minoru , Yamahata Shoji , Enoki Takatomo 
Published: March 2007

AbstractFor the InP HBT being developed for 40 Gbit/s optical communication system realization, the effectiveness of the ledge structure for enhancement of device lifetime due to suppressing generation of the surface recombination current is confirmed. An accelerated life test for this structure shows that the activation energy of the mode in which the current gain decreases gradually is 1.7 eV, that the device life extrapolated at 125°C is more than 1×108hours, and that this degradation does not depend on the operating current density up to 2 mA/µm2. Thus, high reliability at a high current density allowing high‐speed design is realized. Also, the degradation mechanism of the current gain is analyzed. It is found that sudden degradation can be controlled by increasing the layer thickness of the emitter and can consequently be eliminated. The above results confirm that the authors' InP HBT has sufficient reliability for practical implementation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20320
A fingernail‐mounted tactile display for augmented reality systems
Authors: Ando Hideyuki , Watanabe Junji , Inami Masahiko , Sugimito Maki , Maeda Taro 
Published: March 2007

AbstractThere have been many efforts to present skin tactile information to the fingertips. In these studies, however, the tactile stimulus has been presented to the pad side of the finger. In that approach, it is difficult to superimpose virtual tactile information on the tactile information of the real world. Consequently, this paper proposes a tactile display device in which vibration is applied to the fingernail side, not to the pad side of the finger, so that a virtual undulating sensation can be superimposed on the real‐world sensations obtained during the scanning action of the finger. The proposed device is based on the phenomenon that when a vibration is applied while the finger is scanning an object, a perception of undulation rather than of vibration is produced. This study measures the pressure change produced on the pad side of the finger in such a scanning operation and investigates the mechanism that causes the perception. The vibration timing required to present an arbitrary virtual convex width is determined by a psychophysical experiment. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 56–65, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20355
Signed power‐of‐two expression for multipliers of lifting wavelet for image compression
Authors: Tonomura Yoshihide , Iwahashi Masahiro , Tsubone Tadashi , Kambayashi Noriyoshi 
Published: March 2007

AbstractFor image compression, frequency conversions such as the discrete cosine transform (DCT) and the wavelet transform (DWT) have been widely used. The multiplier coefficients used in these conversions are in general defined as real numbers, but they are approximated by a finite word length in the hardware configuration. This causes degradation of the reconstructed images due to mismatch of the coefficient values for the forward and backward transforms. In order to reduce the degradation of the reconstructed images caused by coefficient mismatch, a sufficiently long word length can be provided in setting the finite word length. However, since the compressed image data undergo quantization processing prior to entropy encoding in general, a word length greater than a certain length causes redundancy. Hence, this paper proposes a method in which the coefficient values of each multiplier are provided by the signed power‐of‐two (SPT) representation, using a sum of powers of 2 with as small a (finite) number of terms as possible, so that the error caused by coefficient mismatch is smaller than the error caused by quantization. In this way, a minimum‐size wavelet circuit can be constructed in which the effect of coefficient mismatch between the forward and backward transformations cannot be visually recognized. It was experimentally confirmed by an experiment using the HDL language that the size of the circuit configuration used in the proposed method could be reduced by about 50% in comparison with the circuit in which the sum of the same number of powers of 2 is assigned to each multiplier coefficient. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 47– 57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20272
A data hiding method for JPEG 2000 coded images using modulo arithmetic
Authors: Jin Hong Lin , Fujiyoshi Masaaki , Seki Yusuke , Kiya Hitoshi 
Published: March 2007

AbstractThis paper proposes a novel data hiding method for JPEG 2000 coded images that embed multi‐level information into quantized discrete wavelet transformed coefficients. Since the proposed method hides information represented as an integer to a transformed coefficient rounded to an integer, a JPEG 2000 code‐stream conveying data keeps its standard JPEG 2000 code‐stream structure. The proposed method is able to extract hidden data without memorizing embedding positions; it thus chooses transformed coefficients to which data is hidden freely. This characteristic makes the proposed method suitable for hiding data to a JPEG 2000 coded image with consideration of Region of Interest (ROI) coding that is a major feature. Simulation results show the effectiveness of the proposed method. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 37– 46, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20286
FFT‐based fast conjugate gradient method for real‐time dereverberation system
Authors: Furuya Ken'ichi , Kataoka Akitoshi 
Published: March 2007

AbstractWhen speech at a location away from a microphone is received, the received speech is degraded by reverberation in a room. To deal with this problem, a semiblind dereverberation method has been proposed in which no prior measurement of the room impulse response is used. However, the fast computation was required because an enormous amount of computation is needed for inverse filter calculation. In this paper, an acceleration method for the inverse filter calculation in the semiblind dereverberation method is proposed. For speed enhancement, the similarity of the correlation matrix to the convolution matrix is considered. By using fast convolution by the FFT in the conjugate gradient method, a dramatic increase in computation speed is achieved. A real‐time dereverberation system was constructed on a personal computer by installing the proposed method and was tested in an actual environment. It was confirmed that the proposed method can achieve high‐speed operation without degradation of dereverberation performance. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 25–36, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20292
Noise removal for degraded images by IBS shrink method in multiwavelet domain
Authors: Lu Jianming , Wang Ling , Li Yeqiu , Yahagi Takashi 
Published: March 2007

AbstractThe wavelet transform has been used for image compression, image restoration, signal processing, and pattern recognition. In most cases, processing is performed with a scalar wavelet using one scaling function. However, the scalar wavelet has the deficiency that the properties of shortness of support, regularity, orthogonality, and high vanishing moment are not shared at the same time. Recently, the multiwavelet, consisting of several scaling functions and several wavelet functions, has been proposed. Since several input data are obtained by preprocessing in the multiwavelet transform, many studies of applications of the multiwavelet in the fields of signal processing and image processing are being carried out. Many engineering achievements have been reported. However, little has been reported on the use of multiwavelets for restoration of degraded images. This is a research field with prospects for future growth. In the present research, a threshold shrinking method is proposed in which different threshold values are used for the horizontal, vertical, and diagonal directions at each level and also within the same level in the multiwavelet domain for degraded images with superimposed Gaussian noise. The effectiveness of the proposed method is demonstrated by a computer simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 15– 24, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20295
Performance analysis of UWB impulse radar receiver using parallel IPCP
Authors: Hatano Hiroyuki , Yamazato Takaya , Okada Hiraku , Katayama Masaaki 
Published: March 2007

AbstractThis paper considers a vehicle‐borne target detection system for short range in which an UWB (Ultra Wideband) impulse radar is used. The UWB impulse radar uses a pulse with widths of less than nanosecond order. Therefore, many multipath returns are observed on the receiving side. An IPCP (Inter‐Period Correction Processing) receiver that resolves complexity of the receiver caused by multiple paths has been proposed. However, the integration time of the correlator in the IPCP receiver is limited by the period of the transmission signal (code length) and affects the range measurement accuracy. This paper considers vehicle mounting for applications. In order to assure safety, a receiver is constructed with several IPCP receivers in parallel, so that the range measurement accuracy is improved. In addition, a receiver which reduces the complexity of threshold setting in the conventional IPCP receiver when several targets are detected is proposed. The outputs of these receivers are derived analytically and improvement of the range measurement accuracy is confirmed. Further, based on the analytical results, the output of each receiver is characterized and the relationship of the threshold, detection probability, and false error probability is derived. Finally, the characteristics of use of the receiver as a vehicle‐mounted radar are evaluated by simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 1–14, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20303
A new method for transient stability analysis
Authors: Yorino Naoto , Saito Takeshi , Kamei Yoshifumi , Sasaki Hiroshi 
Published: March 2007

AbstractThis paper proposes a brand‐new method for transient stability analysis in power systems. The proposed method directly computes the critical trajectory for a given contingency to obtain the critical condition of the studied system. Although the method may be useful for general nonlinear dynamic systems, it is applied to the problem of obtaining a controlling UEP, unstable equilibrium point, which provides inevitable information for the energy function methods to assess transient stability. Namely, the proposed method effectively yields a critical trajectory on PEBS together with the controlling UEP, thus improving the conventional BCU method. The effectiveness of the proposed method is demonstrated in 3‐machine 9‐bus and 6‐machine 30‐bus systems. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 26–33, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20245
Magnetic suspension force in an induction bearingless motor with a squirrel cage rotor
Authors: Katou Tatsuya , Chiba Akira , Fukao Tadashi 
Published: March 2007

AbstractTheoretical equations of magnetic force in an induction bearingless motor have been reported. In the bearing‐less motor, both 4‐pole and 2‐pole windings are stored in stator slots for torque and suspension force generation. In the analysis, squirrel cage rotor currents are considered. These currents are induced by both torque and suspension winding currents. Inductance matrix is represented by four sets of three‐phase windings, thus a 12×12 matrix is constructed. A simplification and reasonable assumptions are introduced to obtain understandable expressions for suspension force and torque representation. The rotor flux linkages in an induction bearingless motor are derived, and a simulation model of suspension force is then constructed. It is shown that the response and the phase of suspension force are delayed in the case of cage rotors. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 77–87, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20340
Stability analysis methods for delta operator polytopic polynomials
Authors: Matsuda Tadasuke , Kawabata Keishi , Mori Takehiro 
Published: March 2007

AbstractStability analysis of a linear uncertain polynomial system in parameter space is one of the central themes of recent control theory. It often requires an enormous number of stability checks with conventional stability test methods. A delta operator polytopic polynomial, a convex combination of some delta operator vertex polynomials, is one of such cases. In this paper, robust stability is addressed for polytopic delta operator polynomials and several necessary and sufficient stability conditions are derived. The delta operator, an operator used to express discrete time systems, is known to have significant features: numerical advantage in implementation and ability to smoothly connect the z‐operator with the Laplace operator. Based on this last feature and on the celebrated Edge theorem, we first derive three kinds of exact stability conditions for the uncertain delta operator polynomials. We then extend the directional stability radius method, which was developed for diamond polynomials, so that it can also be applied to polytopic polynomials. This extension gives rise to the fourth stability test. Furthermore, it is shown from the result of the numerical experiments with these stability analysis methods that one of these four methods, which uses eigenvalues of matrices, turns out to be most efficient for stability analysis of the polytope. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 56– 64, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20433
R‐learning with multiple state‐action value tables
Authors: Ishikawa Koichiro , Sakurai Akito , Fujinami Tsutomu , Kunifuji Susumu 
Published: March 2007

AbstractWe propose a method to improve the performance of R‐learning, a reinforcement learning algorithm, by using multiple state‐action value tables. Unlike Q‐ or Sarsa learning, R‐learning learns a policy to maximize undiscounted rewards. Multiple state‐action value tables cause substantial explorations as needed and make R‐learning work well. Efficiency of the proposed method is verified through experiments in a simulated environment. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 34– 47, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20473
Proposal of permanent magnet repulsive maglev transportation system: possibility of automobile with magnetic levitation
Authors: Moriyama Shin‐Ichi 
Published: March 2007

AbstractThis paper describes a maglev transportation system for automobiles. The track is an array of permanent magnet blocks, and the levitating body is the bedplate which consists of permanent magnet plates, propulsion coils, levitation coils, and guidance coils. The feature of this system is that an automobile equipped with the bedplate is free to approach into the track or to swerve from the track by using four wheels with the lift. The force acting on the levitating body is calculated on the assumption that each permanent magnet can be expressed as a surface current. From the calculation results, it is proven that an automobile of 4.35 m length, 1.8 m width, and 1700 kg weight can run at a speed of 500 km/h against the air resistance force of 3704 N on the condition that the battery has an output of 337.5 V and a capacity of 190 Ah. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 65– 76, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20491
Relationship between grain boundaries and electrical degradation of ZnO varistors
Authors: Takada Masayuki , Yoshino Hiroyuki , Yoshikado Shinzo 
Published: March 2007

AbstractThe effects of the electrical degradation characteristics and microstructure of Sb2O3‐added ZnO varistors were investigated by field emission scanning electron microscopy (FE‐SEM), energy dispersion X‐ray spectroscopy (EDX), optical microscopy, X‐ray diffraction (XRD), and voltage– current (V−I) characteristic measurement. The nonlinearity index α of the V−I characteristic for Bi‐Mn‐Co‐Sb2O3‐added ZnO varistors decreased with increasing amount of Sb2O3 after electrical degradation. Twin crystals of ZnO were formed by the addition of Sb2O3. The number of twin crystals with two c‐axes perpendicular to the twin plane increased and the number of twin crystals with two c‐axes parallel to the twin plane decreased with increasing addition of Sb2O3. It is suggested that electrical degradation is affected by a combination of orientations of ZnO grains containing twin planes and that a double Schottky barrier may not be formed in the twin plane. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 1– 9, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20493
Evaluation of audible noise from surface processing conductors for AC overhead transmission line
Authors: Miyajima Kiyotomi , Tanabe Kazuo 
Published: March 2007

AbstractCorona discharge may cause audible noise, and it is frequently generated from wet conductors of high‐voltage AC overhead transmission lines. Audible noise arises more easily from new conductors that have lubricating oil on their surface than from aged conductors. In this paper, the corona characteristics, particularly the audible noise, of conductors having various wetting properties are presented for the purpose of developing a corona‐free conductor for AC overhead transmission lines. It was found that a conductor having a super‐hydrophobic surface exhibited a minimized audible noise level, but it does not have sufficient durability for practical applications. Furthermore, a conductor having a super‐hydrophilic surface made by thermal spraying of TiO2 showed good performance regarding the suppression of audible noise. The thermal spraying of TiO2 seems to be an effective processing technique that has sufficient durability for practical applications. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 19–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20509
A novel Fcγ receptor ligand augments humoral responses by targeting antigen to Fcγ receptors
Authors: Jensen Mark A. , Arnason Barry G. W. , White David M. 
Published: March 2007

AbstractGenerating efficient antibody (Ab) responses against weak antigens remains challenging. Ab responses require antigen (Ag) uptake by antigen‐presenting cells (APC), followed by presentation of processed Ag to T cells. Limited uptake of antigenic peptides by APC constrains Ab responses. Here we improve vaccine efficacy by targeting Ag to Fcγ receptors (FcγR) using R4, a recombinant FcγR ligand. R4 has four repeats per chain of the hinge region and CH2 domain (HCH2) of human IgG1. HCH2 encompasses the FcγR binding site. The repeats are linked to the human IgG1 framework. To test R4 in augmenting Ag uptake, we expressed human serum albumin domain 1 (HSA1) at the N terminus of R4 to produce HSA1R4. HSA1R4 (50 μg) administered to mice in Ribi adjuvant induces up to 1100‐fold higher HSA1‐specific IgG titers than HSA1 (p<0.001). HSA1R4 (250 ng) induces up to 130 times more anti‐HSA1 Ab than HSA1Fc, a protein with HSA1 linked to the IgG1 framework (p<0.001). HSA‐reactive T cells proliferate more briskly to HSA1R4 than to HSA1Fc (p<0.008). Immunization with HSA1R4 yields greater T cell reactivity to HSA1 ex vivo than immunization with HSA1Fc (p<0.004). Linking antigenic peptides to linear HCH2 polymers may facilitate vaccine development.