bluuebunny/crossref_metadata_2025_split huggingface dataset:
Double‐talk detection for adaptive noise canceller
Authors: Mizuno Kimiyasu , Kubota Hajime 
Published: July 2007

AbstractIt is known that the estimation accuracy deteriorates in the double‐talk period in the traditional adaptive noise canceller. The deterioration can be ameliorated by the conventional method if the double‐talk period can be detected. However, the detection of the double‐talk period has not been presented (a method is proposed for the adaptive echo canceller, which, however, has a problem in the direct application to the adaptive noise canceller).From such a viewpoint, this paper proposes a double‐talk detection method for the adaptive‐noise canceller. The method is based on the correlation of the exponential weighted square sum and has the following features. No parameter needs to be known beforehand. The result is less affected by the path variation. The distortion to the desired signal can be suppressed. The computational complexity can be reduced by decimation. The method can also be applied to the adaptive echo canceller.In this paper, the validity of the method is demonstrated by a theoretical analysis. The following result is obtained by a computer simulation. When the adaptive noise canceller is controlled by the proposed method, the accuracy of the estimation is improved by approximately 30 dB and the distortion to the desired signal is suppressed by approximately 15 dB, compared to the case where the method for the adaptive echo canceller is used.
Embedded RAM test using flag‐scan register
Authors: Maeno Hideshi , Iwade Shuuhei , Kayano Shimpei , Sakao Masayoshi 
Published: July 2007

AbstractNew test methods and a test circuit for the testing of embedded RAMs on ASICs are proposed. These test methods are based on the scan path method, and a new scan register, called Flag‐Scan Register, which is dedicated to RAM test, has been developed for the test methods. Also, high‐speed testing is possible by using exhaustive pseudorandom addressing. Furthermore, the methods have been applied to gate array‐based RAMs and the effectiveness has been verified.
Improvement of convergence speed in adaptive filter by multirate processing
Authors: Kashimoto Tsuyoshi , Takahashi Shin‐Ichi 
Published: July 2007

AbstractExact estimation of frequencies of sinusoidal signals corrupted by noise is an important problem in a variety of areas, and various kinds of methods for the solution of this problem have been proposed. Among these methods, the adaptive spectral estimation method, which processes data recursively, needs consideration of the convergence property of the adaptive filter as well as the precision of the spectral estimation. In this paper, we propose a method which improves the technique of analytic signal processing used to improve estimation precision slowing the convergence speed of the adaptive filters. This method makes good use of the data discarded by decimation and processes two series of the same statistics in parallel. By this operation, the number of times the coefficients are updated in the adaptive filter is doubled and, therefore, the rate of convergence is much improved. Furthermore, by increasing the number of data by interpolation of the observed data, faster convergence speed than that of the conventional method is realized. This method has an advantage of simple structure. It can be also easily applied to other adaptive filtering using subband filters.
A subclass of petri nets where liveness is preserved under the earliest firing rule
Authors: Ohta Atsushi , Hisamura Tomiji 
Published: July 2007

AbstractThe Petri net is a powerful tool for modeling, analysis, verification, and evaluation of discrete event systems, and liveness is one of the most important analytical properties of the Petri net. On the other hand, introduction of the earliest firing rule gives an extended class of the net that is useful from both theoretical and applicative viewpoints.This paper clarifies a relation between ‘normal’ liveness of Petri nets and liveness of the net under ‘the earliest firing rule.’ POC nets, a subclass of Petri nets where normal liveness is a sufficient condition for liveness under the earliest firing rule are proposed. Then conditions for necessity are investigated, considering the two rules for multiple firing of a single transition, i.e., single servers and infinite servers. This provides a subclass where the two forementioned livenesses are equivalent to each other. Finally, computational complexity for liveness problem is considered.
The “understanding potential scores,” a new estimation score based on the s‐p chart: Definition and experimental discussion
Authors: Miwa Kazuhisa , Shimomura Tsutomu 
Published: July 2007

AbstractA new estimation score, the Understanding Potential Score, based on the S‐P chart that is widely used as an educational estimation method is defined. The value of the Understanding Potential Score of the response increases with the ease of the problem and the ability of the student. Empirical discussions on the results of applied tests indicate that the degree of each subject's understanding of each problem can be measured quantitatively. The relation between the Understanding Potential Score and the ratios of correct to incorrect responses and of confident to unconfident responses are discussed. The relation between the Understanding Potential Score and the transition patterns of responses from post‐instruction tests to retention tests is also examined.These discussions permit greater understanding of the mechanisms of subjects' objective and subjective estimations. The Understanding Potential Score is also applied to the Unified Evaluation Method (a well known estimation method); with the result, a better estimation method is created by combining the S‐P chart analysis and the Unified Evaluation Method.
Spoken language identification by ergodic HMMS and its state sequences
Authors: Nakagawa Seiichi , Seino Takashi , Ueda Yoshio 
Published: July 2007

AbstractThis paper describes an automatic text‐ and speaker‐independent language identification method based on hidden Markov models (HMMs) for acoustic features. The hidden Markov modeling is used to represent the phonotactics for each language. Each language has its proper phonotactics.The HMM topology here is a fully structured (ergodic) model wherein any state could transit to all states. Two kinds of HMMs are used: the discrete HMM (DHMM) with the codebook and the continuous density HMM (CHMM). The HMM was trained using both the Baum‐Welch (forward‐backward) algorithm and the Viterbi algorithm. The latter was used for emphasizing the state transition probability.For comparison, experiments also were conducted on the identification using a mixtured Gaussian distribution model with one state. This single‐state Gaussian distribution model gave the same performance as the HMM trained with the Baum‐Welch algorithm. This is because the transition between states which reflects the characteristics of each language does not affect the likelihood scores very much. This problem was addressed by emphasizing the transition probabilities and using the Viterbi algorithm, which resulted in an improvement in the recognition rates. The trigram for optimal state sequence is introduced. Combining it with the HMM produced the best results.
Analysis of current densities induced inside human model exposed to AC electric field
Authors: Chiba Atsuo , Isaka Katsuo , Onogi Yukio 
Published: July 2007

AbstractThe current induced inside the human body by the mutual interaction between the human body and the ac electric field has been analyzed by the surface charge method and the finite element method. However, in these methods, it is not possible to analyze the current induced inside the human model of a three‐dimensional shape consisting of biological tissues with different conductivities. The authors propose a method for analysis of the current density in the human body of a three‐dimensional shape by taking into account the conductivity of the biological issues via the scalar potential method of the integral equation. The results of the analysis of the induced current density in the model by the present method have been verified from the experimental results of the metallic human model.
Performance analysis method for system bus architectures in multimedia communication terminals
Authors: Sakamoto Hideki , Ishibashi Yutaka 
Published: July 2007

AbstractThis paper proposes a new method for analyzing the performance of system bus architectures, e.g., first‐come/first‐served (FCFS) bus, priority bus transfer control, separate bus, and multiple bus, in a multimedia communication terminal. Performance is analyzed using a queueing network model (QNM). The QNM of each system bus architecture is converted into an equivalent QNM by using virtual server expressions and then analyzed by a queueing network analyzer (QNA). Numerical results show that this method is sufficiently accurate by comparison with simulation results and that the effectiveness of a system bus architecture depends on the relationship between processing speed and bus speed.
Measurement and analysis of charge distributions induced on rectangular AT‐cut quartz resonators
Authors: Watanabe Yasuaki , Sekimoto Hitoshi , Kitada Yoshinori , Oomura Yoshimasa 
Published: July 2007

AbstractFor the design of a strip‐shaped rectangular AT‐cut plate used frequently in recent years, an accurate spurious analysis method is required to avoid many spurious vibrations which have phase variations in both theXandZ' directions. At present, Mindlin's approximate analysis method based on the plate equations has the highest accuracy, although its degree of approximation has not been studied sufficiently.In this paper, the spurious modes excited in a rectangular AT cut are studied. In addition, to investigate the applicability of the plate equation for the analysis of characteristics of these modes, the surface charge distributions of the spurious mode are obtained experimentally and compared with the computations. From the computed results and the experimental results obtained with a highly accurate surface charge measurement system based on the principle of the electric probe, it is found that the spurious modes all belong to the thickness‐flexure and the face‐shear/flexure except for the weak resonances considered to be excited by the nonsymmetry of the plate. It is pointed out that improvement of the degree of approximation of the plate equations requires adjustment of the coupling between the thickness‐flexure modes and the face‐shear/flexure modes.
ATM‐oriented multimedia LAN architecture
Authors: Suzuki Hiroshi , Iwata Atsushi , Ikeda Chinatsu , Mori Naoki 
Published: July 2007

AbstractThe shared media local area networks (LAN) such as Ethernet/FDDI has the bottleneck of bandwidth scalability. ATMLAN based on asynchronous transfer mode (ATM) switch is considered interesting at present as the next‐generation multimedia LAN to dissolve this bottleneck. The research and development of ATM has mostly been promoted for application to the public network. With respect to LAN, a new investigation is needed which includes the architecture since there are various requirements such as compatibility to the existing protocol, the simplification of the network control, and the drastic reduction of the system cost.This paper proposes the ATM‐oriented multimedia LAN (ATOMLAN) architecture which meets the fore‐mentioned requirements. The proposed architecture has the following three features: (1) the ATMLAN addressing, considering the affinity to the existing protocol and the efficient internetworking; (2) the high‐speed connection control to realize a high throughput for the connectionless‐type data transfer; and (3) the simple and efficient traffic control for the high‐speed burst‐multimedia service. Using the proposed architecture, a seamless high‐speed multimedia network can be realized, from the desk‐top to the broadrand network.
Analysis of acoustic characteristics in the vocal tract with inhomogeneous wall impedance using a three‐dimensional fem model
Authors: Matsuzaki Hiroki , Hirohku Tohru , Miki Nobuhiro , Nagai Nobuo 
Published: July 2007

AbstractThe vocal tract can hardly be considered as having a uniform wall impedance. The palate, for example, is hard and the tongue is soft. The wall impedance is obviously nonuniform. However, so far, there is no detailed knowledge about the acoustic characteristics in the vocal tract when the impedance distribution is nonuniform along the vocal tract with a three‐dimensional structure. It may be possible that this nonuniform distribution is one of the factors for naturalness or individuality in the speech production process. From such a viewpoint, it is necessary to investigate this point.This paper considers the sound tube with a circular or elliptic cross section as a simplified model for the vocal tract. The acoustic characteristics within the tube, when the distribution of the wall impedance is varied, are analyzed in three dimensions using FEM; and the result is reported. The following properties are shown as a result.When the wall becomes softer or when the cross section is deformed from circular to elliptic, the formant bandwidth increases. At the same time, the sound pressure distribution as well as the particle velocity distribution decrease their amplitude. Another aspect is that the sound wave deviates from the planar wave due to the wall impedance and the shape of the wavefront is affected by the impedance distribution.
A practical algorithm for DC operating‐point analysis of large‐scale circuits
Authors: Inoue Yasuaki 
Published: July 2007

AbstractSPICE‐type general‐purpose circuit simulators are used widely as a support tool for circuit design. It often happens, however, that the do operating‐point analysis does not converge. To cope with such a situation, various approaches have been proposed based on continuation methods with the global convergence property, but these have yet to come to the stage of practical application to large‐scale circuits.This paper proposes a practical algorithm which can be implemented on the general‐purpose circuit simulators with modified nodal formulation, for determining the de operating‐point of large‐scale circuits. As the first step, the concept of “modified cut‐set analysis” is introduced and some properties of the modified nodal equation are presented. Then it is shown, in practical circuits, that the convergence of the algorithm is theoretically guaranteed. The proposed algorithm is then implemented on an existing general‐purpose circuit simulator and applied to a bipolar analog LSI to demonstrate its effectiveness. For the LSI circuit formulated in 18, 553 modified nodal equations, the de operating point was determined in 270 minutes using an IBM RS6000‐550.
An identification method for nonminimum‐phase ARMA system using phase information derived from third‐order statistics
Authors: Miyazaki Nozomi , Hamada Nozomu 
Published: July 2007

AbstractOne of the most important problems in signal processing is to investigate the dynamics of the signal through the statistical analysis of the random signal and to identify the model that describes the generation process for the signal. Until now, the second‐order statistics, such as autocorrelation, has been used for this purpose. A problem then is that the second‐order statistics do not contain the phase information of the signal, and it is impossible to analyze the nonminimum‐phase signal.From such a viewpoint, recently, considerable attention has been given to analysis of the signal using the higher‐order statistics which contain also the phase information of the signal. In this paper, the observed signal is modeled as an output of the linear time‐invariant system with the non‐Gaussian white process as the input. A method is proposed which identifies the signal generating system parametrically using the third‐order cumulant of the observed signal. The outline of the method is as follows.The all‐zero system with the same phase response as the system to be estimated is determined from the cepstrum of the third‐order cumulant of the observed signal. Then, by applying the phase‐invariant transform to the all‐zero system, the poles and zeros of the system are rearranged to match the amplitude response of the system. Since the third‐order cumulant is insensitive to the Gaussian additive noise, another feature of the method is that it is effective even if a Gaussian additive noise is added to the observed signal.
Singular point analysis for dynamical systems with many parameters‐an application to an asymmetrically and densely connected neural network model
Authors: Tanaka Hisa‐Aki , Okada Atsushi , Horiuchi Kazuo , Oishi Shin'Ichi 
Published: July 2007

AbstractIn the nonlinear dynamical system, the singular point analysis (Painleve test) is known to be an analytic method for identifying integrable systems or characterizing chaos. In this paper, nonlinear dynamical networks, which are simplified models for mutually connected analog neurons, are studied mainly in terms of the singular point analysis by introducing the complex time. The following results were obtained: 1) some conditions for integrability and first integrals are identified; 2) as an application of Yoshida's theorem, it is proven that many cases in our system are (algebraically) noninegrable; 3) a self‐validated numerical algorithm is proposed to overcome some difficulties known to appear in applying the singular point analysis (Yoshida's theorem) to higher‐order systems.
SAR image reconstruction using a Kalman filter
Authors: Shirakawa Tomoaki , Kitajima Hideo , Ogawa Yoshihiko , Shimono Tetsuo 
Published: July 2007

AbstractThis paper proposes a new image reconstructing algorithm for a synthetic aperture radar (SAR). For fast computation, the proposed method uses a Kalman filter in the time domain while many conventional methods use frequency domain procedures. This method is applicable to real‐time imagery because images are recursively reconstructed. Through a reconstruction simulation by pseudo data, it is shown that a superior reconstructed image is obtained by the proposed method as compared to the conventional method.
A very large vocabulary continuous speech recognition algorithm for telephone directory assistance
Authors: Minami Yasuhiro , Yamada Tomokazu , Shikano Kiyohiro , Matsuoka Tatsuo 
Published: July 2007

AbstractThis paper proposes a speech recognition algorithm for large vocabulary continuous speech. The proposed algorithm is based on the hidden Markov model (HMM)‐LR algorithm using a generalized predictive LR parser and phoneme HMMs. The following three techniques are applied to improve recognition performance and reduce processing time.The forward and the backward likelihood are used to accurately determine the likelihood in the beam search.To reduce the trellis computation in HMM speech recognition and for efficient search, only the speech frames in which the predicted phoneme seems to exist are used by the window for phoneme matching.For efficient search, adjusting identical phoneme sequences are merged by checking the stack and the state of the LR parser.The algorithm was applied to a telephone directory assistance task involving more than 70, 000 subscribers. A recognition experiment for continuous word utterance was done. The sentence recognition rate was 85 percent for speaker‐dependent speech recognition; the sentence recognition rate was 71 percent for speaker‐independent speech recognition. The sentence understanding rate was 59 percent for speaker‐dependent speech recognition with spontaneous utterances.
Phoneme HMM evaluation algorithm without phoneme labeling applied to continuous speech hmm evaluation
Authors: Minami Yasuhiro , Matsuoka Tatsuo , Shikano Kiyohiro 
Published: July 2007

AbstractPhoneme Hidden Markov Model (HMM) are generally evaluated in terms of the phoneme recognition rate by using speech data extracted based on phoneme labels. This paper proposes an evaluation method that does not use phoneme labels for extraction. Consequently, phoneme HMMs can be evaluated even if a speech database without phoneme labeling is used.In this study, concatenation training of the phoneme HMMs is executed using a large‐scale speaker‐independent continuous‐speech database. Evaluation of the HMM phoneme recognition rate which is a function of the number of training speakers, using the proposed evaluation method demonstrates its effectiveness.
A new HVHD model four‐layer channel router using a channel‐graph
Authors: Rhee Byungho , Sugai Yasuo , Hirata Hironori 
Published: July 2007

AbstractThis paper proposes a new HVHD four‐channel routing technique using the channel‐graph. The diagonal routing model, which differs from the conventional four‐layer channel routing, is introduced in the proposed method; and the nets for the diagonal routing are selected by the algorithm based on the weighted channel‐graph. The rest net, left after the diagonal routing, is routed in HVH three‐layers.The proposed method is applied experimentally to several benchmark data, including Deutsch's difficult example. It is shown that tracks are reduced by approximately 20 percent compared to the conventional four‐channel routing method, and the result by the proposed method is closer to the result of the conventional five‐layer routing. Thus, the effectiveness of the proposed method based on the channel‐graph is demonstrated.
Determining element‐value for linear resistive star circuits containing two noncontact nodes
Authors: Suzuki Yoshihiko , Matsuura Hideaki 
Published: July 2007

AbstractThis paper considers the method that measures the network‐element values for the linear resistive network containing the inaccessible nodes and a network topology that is known and element values that are unknown. Measured data at the accessible nodes are used. Whether all of the element values can be determined from the measured data is dependent on network topology. A discussion of what type of configuration for which element values can be determined is presented. A perfect solution is not obtained when the inaccessible nodes number more than two. A new method of determining the element values is given for the circuits containing two inaccessible nodes.
Comparison of text‐independent speaker recognition methods using vector‐quantization distortion and discrete and continuous HMMs
Authors: Matsui Tomoko , Furui Sadaoki 
Published: July 2007

AbstractThe results of speaker recognition methods using vector quantization (VQ) distortion and discrete or continuous ergodic hidden Markov models (HMMs) are compared. The effectiveness of these methods is examined from the viewpoint of robustness against utterance variation such as differences in content, temporal variation, and changes in utterance speed. It is shown that the continuous HMM performs much better than the discrete HMM and its performance is close to that of the VQ distortion method. When the amount of training data is limited, however, the VQ distortion method achieves a better recognition rate than the continuous HMM. The transition information between the states is shown to contribute little to identifying the individual characteristics of a voice. An increase in the number of states or in the number of mixture components in a state both have an equal effect, and recognition performance is almost completely determined by the product of these two numbers.