IEEJ Transactions on Electronics, Information and Systems
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
Volume 120 , Issue 1
Showing 1-28 articles out of 28 articles from the selected issue
  • Yasumitsu Miyazaki
    2000 Volume 120 Issue 1 Pages 1
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Jianqing Wang, Takahiro Joukou, Osamu Fujiwara
    2000 Volume 120 Issue 1 Pages 2-7
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Since biological hazards due to RF exposure are caused mainly by a temperature-rise in tissue, the effect of localized SAR for portable telephones should also be related to the temperature-rise in the human head. Although the SAR is known to be directly proportional to the antenna output power of portable telephone, the dependance of temperature-rise on the antenna output power remains unclear. In this paper, the relationship between the peak temperature-rise in the human head and the antenna output power was investigated by using the FDTD method in conjunction with a detailed human head/portable telephone model. It was found that the peak temperature-rise in all types of tissue is approximately proportional to the antenna output power. It was also found that the peak temperature-rise in the brain can be calculated from the blood-flow and the heating potential.
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  • Al Zaher Samir, Jianqing Wang, Osamu Fujiwara
    2000 Volume 120 Issue 1 Pages 8-13
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Ferrite cores are commonly attached to a cable/wire for suppressing the electromagnetic noise emission from digital information and communication equipment. In this paper, an equivalent circuit for the load effect produced by a ferrite core attached to a wire above a ground plane is investigated. A practical method for determining the equivalent circuit parameters is presented, and the resultant load effect is calculated. This approach is validated by measuring the scattering transmission parameters for the wire with attachment of a commercially available ferrite core above a ground plane.
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  • ITOH Member, Taiji SATOH
    2000 Volume 120 Issue 1 Pages 14-19
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a new data compression method for a Japanese-text file, where the text is written in shift-JIS (JIS X 0208) codes. In the first pass, a dictionary array is built up by the higher frequency of both single and double byte characters. In the second pass, all the registered characters are replaced with the dictionary items: the code OxFF is put into a compressed file in front of non-registered ASCII character so as to distinguish non-registered characters from registered ones. It takes O (1) time on a hashing basis to confirm whether each input character belongs to the dictionary, and to transfer its code to a dictionary item. Furthermore, the run-length encoding is applied to a sequence of consecutive identical characters for the purpose of accomplishment of the much higher compression ratio. The code OxFE is a indicator to start this encoding. A feature of the method is to be a non-modal type of compression.
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  • Makoto Iwasaki, Tomohiro Shibata, Nobuyuki Matsui
    2000 Volume 120 Issue 1 Pages 20-26
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper presents a novel mathematical model-based compensation algorithm for the nonlinear friction in table drive systems using Group Method of Data Handling (GMDH). In the proposed compensation, the nonlinear friction can be autonomously modeled as a polynomial expression of appropriate control state variables according to the process of GMDH and, as a result, the complicated structural modeling and its parameterization, indispensable in conventional model-based strategies, can be completely eliminated. In addition, since the proposed GMDH-based model can easily achieve the generalization ability for table drive condition, the robust compensation for friction can be attained against the change of drive conditions. The proposed algorithm has been verified by experiments using a table drive system of actual machine tools and proved the significant performance improvement in the trajectory control with velocity reversal motion.
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  • Yoshiyuki Hattori, Hiroshi Tadano, Hiroshi Nagase
    2000 Volume 120 Issue 1 Pages 27-33
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Undesired behavior such as dc output voltage shifts in analog IC's caused by RF noise is becoming a serious problem for automobiles. This paper describes the analysis of dc output voltage shifts in a voltage regulator IC when large radio frequency (RF) signal injected to each terminal. First, comparison of experimental results and harmonic balance (HB) simulation results are presented. In this simulation, 4-terminals Gummel-Poon model was used as the transistor model and parasitic capacitors in isolation region were taken into account. Reasonable agreement between these results was obtained. Next, the cause of the dc voltage shifts due to RF injection was analyzed using HB. It was found that the shifts were mainly caused by rectification of the RF in base-emitter junction in amplifier stage transistor of the IC. Also, we proposed an effective method, which could be applied on the IC, in order to suppress the dc voltage shifts.
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  • Hiroshi Yamaguchi, Atsushi Teramoto, Toshio Iri, Isao Horiba, Noboru S ...
    2000 Volume 120 Issue 1 Pages 34-39
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    X-ray images have been used as a way of inspecting solder joints of BGA packages and CSP. But, in X-ray images, other parts are piled up, besides the solder joints which are being subject to inspection. We propose a new method for extracting the solder joints using energy subtraction method. The technique employs the fact that photon energy characteristic of attenuation coefficient is specific to the materials. Concretely, the X-ray spectrum is made to change by appropriately controlling the voltage of the X-ray tube, and two images are taken. Next we conduct contrast correction so that the gray level of the region where X-ray does not permeate solder joints may become equal. Lastly, by subtracting the images, the lead, which is the main constituent of the solder, is extracted. This technique has been verified through both the simulation studies and the prototype system. A good result where solder joints are clearly extracted is provided. By using this technique, it becomes easy to extract automatically the region of the solder joints from X-ray images.
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  • Akihiro Torii, Haruna Kato, Akiteru Ueda
    2000 Volume 120 Issue 1 Pages 40-45
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We propose a miniature actuator which can move in x, y and _??_ directions without guide rails. The proposed actuator consists of piezoelectric and electromagnetic elements. The structure of the actuator and the principle of the motion are described. Since the electromagnetic field does not have an airgap, the proposed actuator uses the electromagnetic flux effectively. The electromagnetic force is controlled for holding the actuator on the slope. The measured electromagnetic force is large enough for the actuator to hold on a slope. Small displacements in the linear and the rotational directions are realised by the deformations of the piezoelectric elements. The displacements in linear and rotational directions were proportional to the applied voltage of the piezoelectric actuators. The μm range linear step displacement and the μrad range rotational step displacement are realised.
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  • Yoshifumi Morita, Yoshihito Shimada, Takahiko Mori, Hiroyuki Ukai, His ...
    2000 Volume 120 Issue 1 Pages 46-52
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The modeling error arising in modeling of flexible manipulators is mainly classified into two uncertainties. One is the structured uncertainty caused by the unknown and changing parameters, and another the unstructured uncertainty caused by the residual modes of elastic vibrations. In order to improve the control performance, we have proposed a robust control strategy for the trajectory tracking control of multi-link flexible manipulators. This controller was designed on the basis of the model decomposition by an integral manifold approach and the composite control.
    In this paper, we show the experimental study on the effectiveness of the control strategy proposed in the previous paper. For this purpose, we apply the control strategy to the one link flexible arm. This controller consists of the slow controller based on VSS control and the fast controller based on strain feedback. By performing some experiments, the effectiveness of the proposed controller is discussed from the viewpoint of the adequacy for the control strategy based on the model decomposition, the slow controller based on VSS control, and the tip position control based on integral manifold.
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  • Tinghsu Su, Muneaki Ishida, Takamasa Hori
    2000 Volume 120 Issue 1 Pages 53-60
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Variable speed drive systems of the 3-phase HB-type stepping motors are widely used because of their low speed and high torque property, inexpensiveness, robustness, low power loss, etc.. Open-loop speed/position control is applied to these motors because they have simpler construction and require no speed sensor for synchronous type motor. However, the motors are salient-pole machines, and periodical torque ripple such as cogging torque is produced due to saliency of the motors when they rotate. It causes mechanical vibration and acoustic noise.
    In this paper, authors propose a repetitive control using acceleration sensor to reduce the vibration of the 3-phase HB-type stepping motor with cogging torque ripple. A mechanical system, where the acceleration sensor is attached to the motor or load frame to detect the vibration due to the torque ripple of the motor, is constructed. Because the vibration varies periodically due to the cogging torque, the repetitive control is effective for reduction of the vibration. The online Fourier Transformer (FT) is applied to the vibration signal detected by the acceleration sensor before inputted to the repetitive controller. All higher and lower order harmonics of the vibration will be cut off by the Fourier Transformer except a particular frequency component such as fundamental one, second order one, etc. of the vibration signal and therefore the stability of the control system is improved. Approximate analysis is performed to study the stability of the repetitive control system. Effectiveness of the proposed method is confirmed by the experimental results.
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  • Hitoshi Azuma, Yasumitsu Miyazaki
    2000 Volume 120 Issue 1 Pages 61-67
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In recent years, many kinds of radio communication systems are widely used. Radio wave disturbances caused by obstacles, on the propagation path, interfere with these communication systems. Disturbances of television broadcasting are problems, which affect us daily. The purpose of this research is to determine the characteristics of radio wave disturbances caused by airplanes. We calculated the near-field electromagnetic scattering with FDTD method, and evaluated the far-field using near-to-far-field transformation with equivalent electromagnetic current. The validity of this analysis was evaluated by comparing the analytical result with experimental result. The disturbance characteristics of the field below airplane are also examined.
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  • Yasumitsu Miyazaki
    2000 Volume 120 Issue 1 Pages 68-73
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Studies on X-ray in the nanometer electromagnetic region are very useful for nanospace fabrication, information and high-energy transmission and control techniques of Angstrom size structures in biomedical sciences and technology. In this paper, studies on the electromagnetic fields in uniformly curved X-ray gra-dient fiber are reported and in the curved section, mode conversion of beam propagation, beam broadening and beam center are presented.
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  • Nao FUJIWARA, Kiyoko YOKOYAMA, Kazuyuki TAKATA, Masanori MOYOSHI
    2000 Volume 120 Issue 1 Pages 74-81
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, the evaluation results of the autonomic response to the linear acceleration are described. The heart rate and the blood pressure variability was analyzed. We analyzed the significant difference of the heart rate and the blood pressure variability between with and without the acceleration load. The correlation between the acceleration and the heart rate or blood pressure variability was analyzed. These statistical analysis were done that two or more targeted ranges of the acceleration are changed. There was significant difference at the heart rate variability under the low acceleration load and at the blood pressure variability under the high acceleration load. The frequency of the blood pressure variability was corresponded to the frequency of the liner acceleration load. The influence of the acceleration remarkably appeared to the blood flow and the blood pressure.
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  • Yasuo Sakaguchi, Tomoaki Nakano, Kazunori Higuchi, Kazuhiko Sugiyama, ...
    2000 Volume 120 Issue 1 Pages 82-87
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In the automobile, various information such as route guidance or road traffic information is provided. Characters and images displayed on a on-board display are increasing. In order to drive safely and smoothly, visibility improvement of on-board display will be more and more important. Development of on-board display which is easy-to-look for older people and robust to environmental change is strongly requested. We propose a method to decide character size and contrast between the character and the background for the condition of displayed characters and symbols.to design on-board display images. This method estimates legibility of the characters based on the spatial frequency property of human vision which vary with the age or environmental luminance. This method will help desiring easy-to-look image of on-board display.
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  • Toshimitsu Tanaka, Kentaro Matsui, Masato Agata, Kazushi Hirano, Masah ...
    2000 Volume 120 Issue 1 Pages 88-97
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We proposed a system for reproducing a soccer game from a video sequence, using animation. The system firstly calibrates camera parameters with white lines drawn on the field, then recovers position of the players and ball. Due to the calibration for each image, free camera panning is allowed. Action of the players is estimated from a change in time of the position of the players and ball. For example, the system interprets that a player kicked the ball if the player is close to the bending point of the ball's locus. The system can judge 9 types of action with 42 variation. We chose this approach because size of players in video images is too small to recognize their pose. Finally, the system synthesizes motion of CG actors by modifying the standard sequence of human action. Parameters of the sequence are adjusted in order to fit moving speed of the CG actors to the measured speed from the video. If a player changes his action in a scene, selected actions are smoothly jointed. The synthesized scene can be viewed from any position on demands.
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  • Isao Naka, Yuichi Noro, Kazukiro Kono
    2000 Volume 120 Issue 1 Pages 98-103
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Various means like sound barrier is used to protect road traffic noise. But it is hardly adapted to control a traffic flow from the point of a road traffic noise. We study the reduction of LAeq by traffic restriction or speed limit or lane limit condition considering Q-V curve.
    The decrease in LAeq that is able to expect under practical regulation in speed limit is 1 to 4 dB. And the decrease by lane limit is 1 to 3 dB. The effect of traffic volume restriction for LAeq is, however, rather small.
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  • Hiroaki TAKATSU, Mitsuo MUNAKATA, Osamu OZEKI, Kiyoko TOKOYAMA, Yosaku ...
    2000 Volume 120 Issue 1 Pages 104-110
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We evaluated the quantitative relationship between the subjective stress value and heart rate variability. The mean values of R-R interval (RRI) and respiratory sinus arrhythmia (RSA), which were reported to be markedly affected by stress, were used as heart rate variability. The following mental workload was performed so as to give wide range loads to the subjects: presentation of research, asking questions in research presentation, research presentation practice, and supine rest. The subjective stress value was obtained as serial values from 1 to 5 by a newly-developed questionnaire. The correlation between the stress value and RRI or RSA when such wide range workload are given was evaluated. There was a high correlation between the subjective stress value and RRI (correlation coefficient, -0.637), but not between the subjective stress value and RSA (coefficient, -0.319) Signal processing of RRI was simpler than that of RSA. These results suggest the usefulness of RRI as an index of the subjective stress value.
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  • Koichi Takahashi, Yasumitsu Miyazaki
    2000 Volume 120 Issue 1 Pages 111-116
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    An automotive radar is part of an ITS framework for automatic driving system, and is a sensor for the detection of the distance and the relative speed between an automobile and the preceding automobile. The objective of this research is to determine the reflection and scattering charateristics of fundamental millimeter wave, by the simulation analysis of millimeter wave of the automotive radar using FDTD method. By this simulation, the signal response of the radar from various shapes of automabile are obtained, from which the received signal characteristics can be analyzed, and signal analysis for high resolution radar development and various other applications are possible.
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  • Tatsuya Shirai, Koji Oguri, Akira Iwata
    2000 Volume 120 Issue 1 Pages 117-122
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Technical improvement of knowledge information processing today, contributes a great expectation for con-struction of computer based diagnosis support system. Our past work showed liver disease diagnosis support system _??_NISYS_??_ _??_NISYS-II_??_ using result of medical blood test could achieve a higher rate of accuracy than results of several statistical method algorithms (1)(2). The new method has possibility to recognize not only disease but also morbidity. However, since the present result of medical blood test uses the information change by disease symptoms, it is still difficult to estimate the break out of the disease and the morbidity transition. On the contrary, recent research results reported that oligosaccharides has a function of information transfer between cell and virus (3). Therefore, analysis of information in oligosaccharide will make possible to estimate disease break out and morbidity transition. However, due to oligosaccharides varieties and complexities, the effective method of analyzing them is yet to be invented. Here we show that oligosaccharide is effective for liver disease diagnosis using neural network. We also propose a new diagnosis method using oligosaccharides, which has possibility to estimate the disease break out and morbidity transition.
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  • Yasushi Hankai, Tomonori Hashiyama, Shigeru Okuma
    2000 Volume 120 Issue 1 Pages 123-129
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Evolutionary Computation (EC) techniques have shown their outstanding performance in the engineering fields for solving combinatorial optimization problems. Although the CPU is getting faster, ECs still take much time because they need a lot of iteration. Some acceleration methods were proposed that modified genetic operators such as mutation, recombination and/or their control parameters. Although these modifi-cations show improvement to some extent, ECs still need much time.
    In many engineering applications of ECs, fitness evaluation takes most of their time. This paper presents a new approach on the acceleration of ECs by reducing time for fitness evaluation. Reducing time for fitness evaluation will result in acceleration of ECs in time domain. Only one chromosome in the population is actually evaluated in the proposed method. Fitness value for the rest of population are estimated using the fitness database updated by the real evaluation. The time for fitness estimation of whole population can be negligible comparing with the actual evaluation.
    The simulation results for designing fuzzy logic controller using Genetic Algorithm (GA) show the effective-ness to accelerate the evolution using the proposed method. Simulation results for De Jong's test functions show that the proposed method is applicable to other problems.
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  • Takeshi Nagao, Tsuyoshi Usuda, Ichi Takumi, Masayasu Hata
    2000 Volume 120 Issue 1 Pages 130-131
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A new pseudo random generator is proposed. Assuming enough memory supply, generated random se-auence are not Deriodic.
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  • Koshichiro Mitsukuni, Hideki Maki, Isao Tsushima, Norihisa Komoda
    2000 Volume 120 Issue 1 Pages 132-137
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In the assembly production control system, inventories are concentrated at the position where supply lead-time and demand lead-time are equal, and inventory and production planning are made at this position. We define this position “Coupling Point”. The Coupling Point is established by demand and supply lead-time changed. Inventory and production planning are made at this new Coupling Point. We evaluate necessary inventories with lot-size reorder system, interval reorder system and multi-stage lot-size reorder system. We also evaluate this method under the demand lead-time variability by simulation. It makes clear that proposed method can decrease the necessary inventories on the demand side of the Coupling Point. This new method has been applied to an electronic device manufacturing process successfully.
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  • Kazuo Ochi, Tielong Shen, Katsutoshi Tamura
    2000 Volume 120 Issue 1 Pages 138-143
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, we solve a robust stabilization problem for cascaded nonlinear systems with uncertainty using a integral forwarding method. It is assumed that the uncertainty is expressed by a gain bounded un-known nonlinear function. First, under suitable assumptions, a storage function which renders the cascaded nonlinear system robust passive is constructed. Next, it is shown that the storage function plays a role of Lyapunov function with which the nonlinear system can be globally robust stabilized by output feedback control.
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  • Hideto Fujita, Masayuki Tejima, Naoki Chiba, Naoaki Komiya, Norio Nomu ...
    2000 Volume 120 Issue 1 Pages 144-150
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Image inspection of LCD line defects is difficult, because the back ground shading is stronger than line defects and different from each other. Therefore, conventional methods such as binarization of projection data are not applicable. In this paper, we propose a new method to find local feature points of line defects by using multi-scale Laplacian filters. The scales of filters applied to the projection data are varied from wide to narrow to obtain multiple wave forms. The most visible points of line defects on projection data are selected from these multiple forms. The line defects are classified to a black line or a white line according to the shape of projection data wave at the selected point. The visibility value s of the defects are also computed from the wave shapes. Experimental results show that our new methods is effective to inspect line defects of LCD.
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  • Qureshi Kalim, Hatanaka Masahiko
    2000 Volume 120 Issue 1 Pages 151-157
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Heterogeneous Parallel Distributed Processing (PDP) systems, which exploit the aggregate power of a network of workstations (WSs) and Personal Computers (PCs) are an inexpensive alternative to the dedicated parallel supercomputing systems. As these systems are widely available in academic and industrial environments, it is becoming popular to use these computing resources to solve time consuming applications. The main problem with such type of cluster computing environment is the continuous change in the performance of individual WSs/PCs which requires an efficient task partitioning, scheduling, and load balancing to get better performance.
    In this paper, we investigate the problem of static and runtime tusks allocation for parallel-distributed image computing system The PDP system has heterogeneity in processors and resources. For such system, we propose an Adaptive Hybrid Task partitioning, Scheduling (AHTS), and load balancing strategy. The investigation is examined on a manager/master and workers model of PDP system The measured results show that, the AHTS strategy dramatically improves the performance of PDP image computing system and remedy the defects of static and Runtime Task Scheduling (RTS) strategies.
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  • Tsugio Nakamura, Hiroshi Kasahara
    2000 Volume 120 Issue 1 Pages 158-167
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, we propose a quasi-parallel divider for numbers of arbitrary word length, which reduces the increase in the number of pins and gates, but not failing the high-speed performance of the parallel processing, by cascading some parallel dividers and by repeating the arithmetic operations using some clock cycles.
    The best way in improving the speed is using the parallel hardware architecture, but it brings the increase of the number of gates, fan-ins and fan-outs as the precision is increased. The public key cryptographic techniques for information security is an good example. In this case, the power residue arithmetic for numbers more than 1, 024 bits is needed because of keeping the adequate security within the reasonable operation time. In such high precision, it will be extremely difficult to be implemented on a single chip with only the parallel architecture, if not impossible. That is why it has usually been realized in the type of sequential circuit using millions of clock cycles.
    A quasi-parallel divider proposed here can perform to any accuracy because it is the chip sliced configuration. When it is to be expanded by a factor of n times of the single chip precision, the increase of the number of gates are 1/n times against that of the conventional parallel architecture, and the propagation delay reduction is 1/n against that of the sequential circuit type.
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  • Kenji Terada, Daisuke Yoshida, Shun'ichiro Oe, Jun'ichi Yamaguchi
    2000 Volume 120 Issue 1 Pages 168-173
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, a range finder using the swinging cubic mirror is proposed. Three-dimensional measure-ment is useful for applications such as robot vision, factory automation, computer aided design, and security systems. Such a large range of applications has led to attempts to develop range finders that enable the three-dimensional shape of objects to be obtained. However, conventional methods were flawed because the measurement range of the sensor was limited by the view-field of the camera. The present method realizes synchronized scanning between the view-field of the camera and the slit projection. In the proposed system, a laser projector and a CCD camera are positioned opposite each other along the optical axis, and a cubic mirror is placed between the projector and the camera. A motor is attached to the cube at its center. As the cube rotates, slit light is scanned across the surface of the object, and the slit light and the view-field of camera are moved in the same direction simultaneously. In order to demonstrate the effectiveness of the present method, experiments are performed using the experimental system and experimental results are presented.
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  • Satoshi Yatsumonji, Hisaya Tanaka, Hideto Ide
    2000 Volume 120 Issue 1 Pages 174-175
    Published: 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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