IEEJ Transactions on Electronics, Information and Systems
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
Volume 122 , Issue 12
Showing 1-27 articles out of 27 articles from the selected issue
  • Noboru Ohnishi
    2002 Volume 122 Issue 12 Pages 1995
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Teruya Yamamoto, Mitsuo Yokoyama, Hideyuki Uehara
    2002 Volume 122 Issue 12 Pages 1996-2004
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A Direct-Sequence/Code Division Multiple Access (DS/CDMA) system is considered to be the system where the interference from other users limits the channel capacity rather than the receiver noise. Therefore, a lot of interference cancellers have been proposed. However, most of them were for the base stations. This paper has proposed an easy interference canceller for lightly equipped systems or terminals, and theoretical analysis has been carried out. The canceller calculates the interference due to other users following the minimum mean square criterion under the assumption that the carrier phase of each signal is known and that the synchronization is established. The estimated interference noise is combined and subtracted from the interference contaminated desired signal. Computer simulations coincide with the analysis revealing two times improvement in signal-to-noise ratio when processing gain is 31 and Eb/No is 20[dB].
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  • Tsutomu Sakata, Junichi Ichikawa, Naoki Inagaki, Nobuyoshi Kikuma
    2002 Volume 122 Issue 12 Pages 2005-2010
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Microstrip Patch Antennas (MSA) are used at dominant mode and rarely used at the higher order modes because of the differences in the radiation pattern etc. In this paper, we have proposed a MSA which consists of a center patch and two slender patches on both sides, each connected to the center patch by two short microstrip lines. This MSA can have a main beam in the boresight direction at three frequencies corresponding to the frequencies of the dominant, the second, and the third modes.
    The optimum structural parameters are sought by the numerical simulation using HFSS of Agilent Co. in order to obtain as high power gain as possible at the boresight direction. The MSA with thus determined parameters is manufactured and tested. The experiment verified that the proposed MSA can have a unidirectional radiation pattern at three frequencies similar to that of the conventional MSA working at the dominant mode frequency.
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  • Tomohiro Nakagami, Hiroshi Matsuo
    2002 Volume 122 Issue 12 Pages 2011-2019
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We propose new fast human detection method and counting system corresponding to the environment where many persons exist in camera view. We develop a human model from the feature of region change of many images of pedestrians which walk toward various directions, and detect two or more persons who are overlapping by matching with difference image and human model. And we propose the axial direction filtering for simplification of matching process. In counting system, we also propose the algorithm which counts measurement line passage of pedestrian using information of passage position and body color. The experiment in the environment where many persons exist in camera view shows that the proposed systems are possible to work in real-time with sufficient accuracy.
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  • Norihide Kitaoka, Naoko Kakutani, Seiichi Nakagawa
    2002 Volume 122 Issue 12 Pages 2020-2027
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently, car navigation systems with the interface based on speech recognition have been realized. When we communicate with computers through speech interface, we cannot avoid misrecognition. However, it is difficult to recover it because of the immaturity of the interface. Detection of user's repetition of misrecognized part can make it easier.
    We propose a method to detect the partial repetition of misrecognized speech using a word spotting technique based on DP matching and N-best hypotheses overlapping measure. We achieved 97.0% of detection accuracy for the repetition and 93.5% of the rejection accuracy for others.
    Next, we tried to improve the recognition accuracy using the detection. Using the choice of vocablary setup based on the detection, we achieved improvement of the recognition performance from 29.0% to 35.1% for repaired speech and from 55.5% to 59.9% for others. When we employed restoring strategy for real time processing, we achieved 33.5% of recognition rate for repaired speech and 58.5% for others.
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  • Daisuke Yamada, Norihide Kitaoka, Seiichi Nakagawa
    2002 Volume 122 Issue 12 Pages 2028-2034
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We discussed the adoption of the features based on the glottal sound source for speaker independent speech recognition. It has been thought that such features cannot contribute to the speaker independent speech recognition because of the dominant speaker dependent factor.
    In this paper, we tried to use pitch, power, LPC residual power, voicing rate, and their regression coefficients as feature parameters for speaker independent speech recognition and found that some features could improved the performance. We discussed the reason of this contribution and concluded that the procedure to derive the regression parameters could reduce the speaker dependent factor which appeared as biases of those features.
    We also tested the parameters on a large-vocabulary continuous speech recognition task and obtained the performance improvement.
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  • Hiroki Yokota, Kimiya Aoki, Toyohisa Kaneko
    2002 Volume 122 Issue 12 Pages 2035-2042
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    As for picture input apparatus, such as an image scanner and a digital camera, high efficiency and the low price are progressing. Electronic processing of printed matter comes to be performed daily. Such input apparatus output raster data. Especially in the case of a character or a drawing, converting raster data to vector data is needed. Although the conversion operation is already mounted with much application, the nuance of the outline of the original figure is not preserved because the boundaries between the figure and the background have degraded through digitalization. Then, in this study, the technique of generating an outline more correctly based on the viewpoint of area preservation was proposed. The experiment using test images and real images was performed, and it was shown that the proposal technique has high capability of area preservation. Furthermore, it suggested about the applicability to volume data.
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  • Masaki Kobayashi, Yoshio Itoh
    2002 Volume 122 Issue 12 Pages 2043-2048
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The active noise control system that has been studied requires the replica of the cancellation path to obtain the updating weight value since the signals for the operation can not be observed. In this paper we propose a structure and an adaptive algorithm for the active noise control system using an adaptive exponential filter that does not require any replica. The adaptive algorithm is based on the steepest descent method that can be easily realized and the updating weight value of the adaptive exponential filter is the correlation of the observable output signal of the adaptive system and the estimation error. The other adaptive filters are composed of the linear transversal system. It is proven that the transfer function after converging completely corresponds to the transfer function of the noise and the cancellation path under a certain condition. Finally, the convergence performance of the estimation accuracy and the tracking performances to the rapid change of the noise and the cancellation path are verified by the computer simulation.
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  • Masaki Kobayashi, Yoshio Itoh
    2002 Volume 122 Issue 12 Pages 2049-2054
    Published: December 01, 2002
    Released: December 19, 2008
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    In this paper we propose the adaptive delay estimation system of the impulse response that has the large time delay. We define the impulse response as the response of an unknown system that is represented by the tandem connection of the delay part, the minimum-phase system and the allpass system without loss of generality. The feature of this adaptive system is to estimate the time delay of the unknown system in high accuracy. The study of the delay estimation system based on such a strict modeling has not been found. The influence of the allpass system on the convergence value of the adaptive system is formulated, and it is shown that this influence is below the length of the impulse response. It was clarified that the delay estimation accuracy of an arbitrary system that has the long time delay becomes below the length of short continuance impulse response by using the proposed adaptive system. Finally, the convergence performance of the estimated delay and the tracking performance of the adaptive system are verified by the computer simulation.
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  • Kentaro Noguchi, Yoshiaki Tadokoro
    2002 Volume 122 Issue 12 Pages 2055-2060
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, we present a new frequency estimation algorithm using an adaptive delay notch filter (ADNF) based on a sign algorithm for a single sinusoid. The feature of the proposed method using the ADFN which can control the number of delay elements is to adapt the time t in signal x(t). That is, the control of the number of delay elements of the ADNF is equivalent to controlling time t in signal x(t) indirectly. Combining the ADNF and the sign algorithm, the proposed method is constructed without the multiplier. By the computer simulations, we show that the frequency estimation based on the controlling the number of delay elements corresponding to time t in signal x(t) can be constructed. Then we compare the proposed method with the adaptive line enhancer in respect to the frequency estimation accuracy and the computational complexity.
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  • Akihiro Torii, Osamu Doi, Akiteru Ueda
    2002 Volume 122 Issue 12 Pages 2061-2066
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, an AFM encoder using an interferometer is proposed. The AFM encoder is a multiple probe AFM. Displacement is measured by the periodicity of the sample used as a displacement standard. Since the AFM realizes atomic scale resolution, the AFM encoder will realize very high resolution. We manufacture the AFM encoder, and the fundamental experiments are carried out. The deflections of the AFM cantilevers are detected by a Michelson interferometer simultaneously. A line-focused red color semconductor laser is used as a light source and a photodiode array is used as a detector. A sample is moved in x and z directions by an AFM stage. The AFM cantilevers detect the surface topography of the sample and the displacement is measured by using the detected signals. In this study, an optical grating, which is 1.2μm periods and 240nm height, is used as a displacement standerd. The periodical signals indicating surface topography of the optical grating are obtained. The resolution of the AFM encoder in x direction is less than 10nm.
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  • Kenzo Obata, Kentaro Noguchi, Yoshiaki Tadokoro
    2002 Volume 122 Issue 12 Pages 2067-2075
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We consider a sound source position estimation algorithm in the large-scale building space like an auditorium. The position estimation is necessary for the automatic operation of the sound image localization. In this paper, we proposed a basic characteristic for the sound source position estimation algorithm based on a phase difference detection of a formant contained in a voice signal. To extract the formant, the proposed algorithm uses the notch bandpass filter (NBPF). Then we detect the phase difference of each formant. As the method for the phase difference detection, we consider study two estimation methods, one of them is a zero-crossing method and the other is a Fourier transform one. As the results, the position estimation performance of the proposed method is clarified by the computer simulation, and we evaluate the proposed method realizing a measurement system.
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  • Katsuyasu Nakano, Yutaka Ota, Hiroyuki Ukai, Koichi Nakamura, Hideki F ...
    2002 Volume 122 Issue 12 Pages 2076-2082
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Applications of digital signal processing technology to electric power systems have received a great deal of attention in recent years. There have been many digital algorithm applied to calculate frequency and phasor. In those, in particular, the PMU(Phasor Measurement Unit) is widely applied in order to detect both r.m.s. value and phase angle of voltage/current at multi points in pwoer systems. The calculation algorithm of the voltage/current phasor in the PMU is based on the recursive DFT(Discrete Fourier Transform). However, in the case when the frequency of power systems is fluctuating and different from the fundamental frequency of DFT algorithm, the calculated r.m.s. value and phase angle have the detection error due to the deviation of frequency.
    The purpose of this paper is to propose a new detection method of the frequency and the phasor in power systems by analyzing the error contained in the volatge phasor due to the deviation of frequency. The numerical simulation results are shown to confirm the effectiveness of the proposed method compared with zero-cross detection method. In particalar, the proposed method has robustness in the case when the voltage wave contains harmonics.
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  • Takenori Aomi, Yoshiaki Tadokoro
    2002 Volume 122 Issue 12 Pages 2083-2090
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently, the studies for human ITS (Intelligent Transport Systems) are performed actively. We proposed a portable human navigation system which can navigate pedestrians by only portable devices. The system detects the pedestrian's position by dead reckoning. Therefore, the proposed system can be used in any place. We construct the portable human navigation system, and also examine the navigation methods. The fundamental method is based on voice information. The expanded method uses both voice and visual information. We made some walking experiments both outside and inside of the buildings to evaluate the proposed system. As a result, we confirmed that the proposed system can navigate pedestrians to the destination without stress.
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  • Kae Doki, Soichiro Hayakawa, Tatsuya Suzuki, Shigeru Okuma, Takeshi Ao ...
    2002 Volume 122 Issue 12 Pages 2091-2099
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a new memory architecture which takes into consideration the computational resource constraint in the real-time search. In the proposed architecture, each data is hierarchically stored in the order of its frequency in the real-timesearch. Moreover, the number of stored data which are checked on-line varies according to the allocated time to find a solution. Therefore, the computational amount which is necessary to recall a stored data can flexibly change according to the current situation, and the efficient recall can be realized even if the allocated computational resource is not enough.
    In this paper, the proposed method is applied to the action acquisition for an autonomous mobile robot in the moving obstacle avoidance problem. The usefulness is verified through some experimental results.
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  • Jun Feng, Toyohide Watanabe
    2002 Volume 122 Issue 12 Pages 2100-2108
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A country-wide Integrated Geographic Information System (IGIS) is very useful in providing good access to essential geographic information, and making sonud decision. The primary objective of such a system is to ensure that users of spatial data should acquire consistent datasets to meet their requirements, even though the data is collected and maintained by different authorities. In this paper, we analyse the relations among map information in a country-wide GIS, and address a Multi-scale/Multi-theme (M2) map information model for manipulating country-wide integrated maps of different scales for different themes. This information model is powerful to integrate various scales of maps uniformly and possesses advanced extensibility. We give the representation of road network in the model, and evaluate our model with a prototype system.
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  • Yoshihide Kato, Shigeki Matsubara, Katsuhiko Toyama, Yasuyoshi Inagaki
    2002 Volume 122 Issue 12 Pages 2109-2119
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Word-dy-word incremental parsing has a serious issue that the results given sequentially do not necessarily represent the correct syntactic relations. That is, syntactic substrutures predictively computed for initial fragments in the incremental parsing process may become wrong for the whole input sentence. This paper proposes a method for calculating the probability that a syntactic structure computed in the incrementalparsing process is correct. Our method is based on probabilistic context free grammar, and it incrementally calculates the probability for each syntactic structure on a word-by-word basis. In our method, incremental parsing outputs syntactic structure at the point when the probability for the structure becomes greater than an adequately determined threshold. Our technique improves the accuracy of incremental parsing. We havemade an experiment using ATIS corpus and ATR speech and language database. The experimental results have shown the effectiveness of our method.
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  • Keiichi Uchimura, Kousuke Matsushima
    2002 Volume 122 Issue 12 Pages 2120-2127
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A traffic problem, such as a traffic accident, traffic congestion and environmental pollution, are serious social issues with the increase in vehicle ownership ratio. As a measure, practical application of system which provides a driver with useful information is desired. In connection with such a background, the trial in which the automated surveillance system of a traffic state and an obstacle using image processing technology is made. This research proposes the traffic flow measurement technique using image sequences taken by a CCD camera mounted on the footbridge. We perform vehicles detection using adaptive background difference processing, and vehicles tracking using the concept of a deformable template matching and a tracking cycle to provide solution to vehicles occlusion. Eventually, the traffic parameter called a traffic volume, a speed, and a space occupancy is computed. In the experimental result, the accuracy and the efficiency of our approach is shown.
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  • Ali Ahmadi, Sigeru Omatu, Michifumi Yoshioka
    2002 Volume 122 Issue 12 Pages 2128-2134
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We present a system for recognition of Persian/Arabic handwritten scripts using Hidden Markov Models (HMMs). The text is segmented to words at first and from words to characters by an appropriate algorithm using the strokes and contour of word image. Then the feature vectors are extracted from sequential vertical frames of characters. Next, a Self-Organizing Map (SOM) is employed for clustering the features and reducing the size of inputs as well as smoothing the parameters of HMMs in classification phase. Finally, by using the HMM the characters are classified, and by concatenating the character HMMs, the word HMM is composed. The system is evaluated with five sorts of Persian handwritten data containing a number of 1, 025 words, and the mean correct classification rate is 97% in word level.
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  • Daisuke Morita, Takeyuki Uchida, Hiroshi Murata
    2002 Volume 122 Issue 12 Pages 2135-2143
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Present authors propose a new design method of optimal deadbeat controller with two-degree-of-freedom. The dynamic characteristic of the system is expressed by the step or impulse response. From the matrix computation by using sampled data of the system's response, can be easily obtained the optimal deadbeat control signal not only for the desired value but also for the disturbance, which minimize the quadratic performance index. Then, the deadbeat controller with two-degree-of-freedom can be designed by using the control signal. This design method can improve both the step-wise desired value tracking characteristics and the step-wise disturbance rejection characteristics respectively and independently from each other. To demonstrate the effectiveness of the proposed method, some numerical examples are also presented. It is shown that, by using this method, better results than those obtained from the preceding one can be obtained.
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  • Hidekazu Machida, Fuminoro Kobayashi
    2002 Volume 122 Issue 12 Pages 2144-2148
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A PLL/PWM motor speed control system, implementing a type of loop filter for PLL, utilizing counters, multiplexer and a comparetor as operation elements for PWM signals, As a result, it can be implemented as a one-chip IC featuring a low gate count.
    In this paper, considering time resolution of integral operation, an improved circuit for removing steady phase error is proposed.
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  • Hironobu Katagiri, Jinglu Hu, Kotaro Hirasawa, Junichi Murata
    2002 Volume 122 Issue 12 Pages 2149-2156
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently many studies have been made on automatic design of complex systems by using the optimization technique such as Genetic Algorithms (GA), Evolution Strategy (ES), Evolutionary Programming (EP) and Genetic Programming (GP). In this paper, a new method named Genetic Network Programming (GNP) which describes the behavior sequences of agents as a network is proposed in order to acquire intelligent behavior sequences. GNP includes judgement nodes and processing nodes in the network. The proposed system can evolve itself by an evolutionary method using mutation and crossover.
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  • Tomoki Hamagam, Seiichi Koakutsu, Hironori Hirata
    2002 Volume 122 Issue 12 Pages 2157-2164
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a new reinforcement learning method based on “Motivation Value” which changes action selection probabilities in order to realize policy which depends on state-action context. The motivation value which this paper defines is a parameter which emphasizes (or de-emphasizes) specific action selection probabilities temporarily, and controls the next action selection probability indirectly at the control phase. Furthermore motivation value is recorded using the form corresponding to each state-action pair like an Q-value and updated with advance of learning. The feature of the method to propose is a practical advantage to be implemented by the comparatively easy extension from general reinforcement learning. In order to investigate the validity of proposed method, the method was applied to the maze problem containing perceptual aliasing problem. Experimental results show this method is effective technique as a learning algorithm under the non-Markov decision process environment which contains perceptual aliasing problems.
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  • Yoshifumi Amemiya
    2002 Volume 122 Issue 12 Pages 2165-2171
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    While some epidemiological papers state that a connection exists between power-line magnetic fields and cancer, experimental studies on animals and cells have shown no substantial effect which resulted from exposure to magnetic fields; that is, there is a discrepancy between the conclusion reached by epidemiology, a non-experimental science, and that by the experimental studies on animals and cells, an experimental science. Therefore, the author thinks that there must be some omissions in the epidemiological papers. In this paper, this author presents an opinion, a hypothesis, that 'every epidemiological paper should be arranged to make increased risk rather large from safety sides not to neglect any of potential causes of a disease, while a detailed examination of the propriety of its premise, the assumption, and of the logicality at its reasoning is a matter that can wait', and shows that some epidemiological papers, such as the Karolinska paper and others, about the connection between magnetic fields and childhood leukemia support the hypothesis.
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  • Koji Murai, Yuji Hayashi, Seiji Inokuchi
    2002 Volume 122 Issue 12 Pages 2172-2179
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The purpose of this paper is to find relations between the body and physiological response to visual simulation of ship rolling and the horizontal visual field. We carry out the experiment that is simulated ship rolling only visually and not mechanically from zero to eight meters wave height at one meters interval for four kinds of horizontal visual field (210°, 150°, 90° and 30°) using the ship handling simulator at Kobe University of Mercantile Marine. We measure subjects gravity center and R-R interval for body and physiological response to the artificially created visual environment. The subjects look visual environment for three minutes in each wave condition. Here, subjects are three experienced persons (navigators) and three inexperienced persons.
    The results showed that the displacement of navigators gravity center were led toward an inclination of the picture created by the simulator with wide horizontal visual field. And the relations between rolling angle and locus length of gravity center took the peak point for all horizontal visual fields. Also, the index with R-R interval and locus length of gravity center were correlated for 210° horizontal visual field.
    From the results, we knew the realistic image with wide horizontal visual filed was influenced on the subject's body and physiology, and it's characteristics was difference between experienced persons and inexperienced persons.
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  • Kyu-Boem Lee, Jeong-Young Song, Kageo Akizuki
    2002 Volume 122 Issue 12 Pages 2180-2188
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In general, most of koreans usually have used Hangul and MS-word as a Word Processor. We studied about the functional efficiency by comparing and analyzing Text Mode Equation Mode, Table Mode, Frame Editor & OLE Mode, Chart Mode and the other Modes to evaluate the common utility used Hangul 97 and MS-word 97 as a Word Processor. As a result, File size, Drag & Drop. Compression and storage etc. have been recognized characters remarkably in each case. We studied about Hangul 97, MS-word 97 as a user for evaluation criteria items. As a matter of fact, we used Tool Book and Director. So, we designed, developed and materialized S/W “garbage generation, separation, and collection” and then we also compared and examined those Text Mode. Sound Mode. Summation Algorithm Mode and Moving image Mode. In consequence, a user's point of view, characters of Tool Book and Director are showed remarkably through the findings of the questionnaire.
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  • Chieko Matsuyama, Toyoshiro Nakashima, Naohiro Ishii
    2002 Volume 122 Issue 12 Pages 2189-2190
    Published: December 01, 2002
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In classes using personal computers, although the necessity and importance of students' touch-typing skills are recognized, it is rarely taught because it is difficult to spare enough time for the training of touch-typing, or because this type of skill training is not considered suitable for university education. The authors have introduced the practice of touch-typing in information processing classes. As a result, substantial improvements of students' touch-typing in skills were obtained in the classes.
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