bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of generation method of modulated‐noise reference signal on speech quality evaluation
Authors: Ogawa Mineyoshi , Irii Hiroshi 
Published: July 2007

AbstractThis paper discusses the modulated‐noise reference unit (MNRU), which is used to represent quantitatively the effect of the quantization distortion due to voice coding on the voice quality. The noise generation method, which has only implicitly been discussed, is formulated; and the effect of various generation parameters on the voice quality evaluation is examined. The following results are obtained. The noise source has a uniform amplitude distribution which simplifies the digital processing compared to the generation of noise with a Gaussian distribution. The effect on the quality is small even if the noise‐generation cycle is short. The simplified method proposed by Bellcore Co., U.S.A., is examined for comparison. It is shown through an international evaluation experiment that there is no significant difference in the result of quality measurement even if the simplified generation method is adopted.
Decomposition algorithms for live and safe free choice nets
Authors: Nishimura Tadaaki , Lee Dong‐Ik , Kodama Shinzo , Kumagai Sadatoshi 
Published: July 2007

AbstractThe free‐choice net is a subclass of the Petri net. It is a class which can explicitly represent both the essential concurrency and the nondeterministic aspects of the concurrent system. the class can be considered as an extension of the state machine where concurrency is included. It can also be considered as an extension of the marked graph where the nondeterministic aspect is included. There have been a number of studies on the free choice net with the dynamic constraint that it should be live and safe (LSFC). This LSFC net has a structural feature: it can be decomposed into a set of strongly connected state machines (called S components). If the minimal set of S components (S decomposition set) covering the given LSFC net can be efficiently determined, it will be possible to derive powerful methods in the analysis and performance evaluation of the parallel system. This paper discusses the polynomial‐order algorithm that determines the S‐decomposition set for the LSFC net.
Parallel adaptive infinite impulse response digital filters using Kalman filters
Authors: Cao Jianting , Yahagi Takashi , Lu Jianming 
Published: July 2007

AbstractThis paper presents a new design method for parallel adaptive infinite impulse response (112) digital filters using Kalman filters in the time domain. the parallel Kalman filter (PKF) and the improved parallel Kalman filter (IPKF) based on the divided estimation of an unknown system's impulse response are extended to parallel adaptive IIR digital filters. the finite impulse response (FIR) digital filters can be replaced by reduced order IIR digital filters. This is particularly useful when high‐order FIR digital filters are necessary. A method is presented that ensures the stability of IIR digital filters with little extra computational effort.
Reliability evaluations of microprocessor system with watchdog timer
Authors: Yasui Kazumi , Nakagawa Toshio , Harata Yoshihisa 
Published: July 2007

AbstractA watchdog timer has been used in many practical fields as a simple method of monitoring the behavior of a microprocessor. However, it is impossible at present to detect any errors that occur in a microprocessor using a watchdog timer. It would be necessary to develop a watchdog timer with more advanced capabilities and to improve the reliability of the entire system, including a microprocessor. This paper considers a microprocessor which has a watchdog timer with self‐checking. Assuming that a microprocessor and a watchdog timer fail mutually independently, we formulate the following stochastic model: when errors of a microprocessor have occurred, a watchdog timer detects them with a certain probability and resets a microprocessor to an initial state. Otherwise, a microprocessor goes to a fault state. We derive reliability measures such as mean operating times and cost effectiveness until the fault of a microprocessor is reached. Further, we evaluate how much more reliable the system with a watchdog timer becomes.
Solution of nonlinear vision problem based on forward and approximated inverse optics models
Authors: Hayakawa Hideki , Wada Yasuhiro , Kawato Mitsuo 
Published: July 2007

AbstractA solution of the nonlinear vision problem based on forward and approximated inverse optics models is proposed. In the solution, the geometrical structure modification in the three‐dimensional (3‐D) world required due to the 2‐D brightness error is separated from that required due to the smoothness constraint. Therefore, a simple and fast algorithm for each modification can be used.First, the optimality of the converged solution in the algorithm and the convergence of the algorithm is proved. In the proof, an optimal solution of the linear optimization problem is used for the approximated inverse optics. Next, the proposed algorithm is applied to the shape‐from‐shading problem. In the problem, a Newton‐like method is used that quickly gives the approximated optimal solution of the linear optimization problem. In computer simulations, it is demonstrated that the proposed algorithm can estimate the shape of an object within a small number of iterations in comparison with the Ikeuchi‐Horn algorithm.
An algorithm for making a correspondence of zero‐crossing points in a wavelet transform domain with second‐order derivative property
Authors: Watanabe Shinji , Saito Takahiro , Cheong Chakeon , Aizawa Kiyoharu 
Published: July 2007

AbstractThe multiscale wavelet transform (MWT) is the method of multiple resolution analysis using the wavelet transform. In MWT with the property of the second‐order derivative, the position of the zero‐crossing point of the transform signal corresponds to the position of the edge of the original signal. the edge has an important role in image information. If the correspondence of the zero‐crossing points related to the edges can be established between scanning lines or between frames by some means, the correspondence can be utilized in the sophistication of image processing (such as motion analysis, stereo matching, interpolation, and noise reduction). From such a viewpoint, this paper discusses the correspondence between the zero‐crossing points in MWT, i.e., the correspondence of scales and the correspondence between two similar signals, and presents a method that provides visually plausible correspondence as a result. Especially for the correspondence between signals, the accuracy of the correspondence of zero‐crossing points is improved by introducing the cost function. Computational complexity is kept within a practical range, by applying the dynamic programming and utilizing the branch structure of the zero‐crossing points among various scales. the idea of cross‐validation is applied to the correspondence of signals between the scanning lines of the image, and a method is composed that evaluates visually the quality of the signal correspondence method by the naked‐eye observation of this image. With this evaluation method, the usefulness of the proposed algorithm for the signal correspondence and its problems are indicated. It is shown that a visually reasonable result is obtained by adjusting the weight coefficient of the multiplication factor of the cost function in the signal correspondence process.
Design of digital allpass functions with specified phase tolerances
Authors: Zhang Xi , Iwakura Hiroshi 
Published: July 2007

AbstractIn this paper, a new method is introduced for designing IIR digital allpass functions with specified phase tolerances. Since the phase error characteristics subject to the desired phase response have been specified in the interest bands, the phase design of digital allpass functions in the form of a linear programming problem can be formulated by using the Remez exchange algorithm. Then the linear equations are solved to obtain a set of filter coefficients and the optimal coefficients in the Chebyshev sense can easily be obtained through a few iterations. By appropriately selecting the initial extremal frequencies, the proposed design algorithm always converges, and the phase error characteristics can be arbitrarily specified. Finally, some design examples are presented to demonstrate the effectiveness of the proposed method.
Transform coding of images based on fractal functional set
Authors: Ogawa Hidenori , Nakagawa Masahiro 
Published: July 2007

AbstractOrthogonal fractal basis functional sets are proposed for the compression of images with long‐tail power distributions. These functional sets are generated by the method of midpoint displacements from deterministic theory and are orthogonalized by the method of Schmidt. From computer simulations of transform data compression coding that uses a transform based on these functional sets and a nonuniform quantizer, the functional sets proposed in this paper are shown to better preserve the self‐similarity of fractal image data when compared to conventional methods that use the discrete cosine function (DCF). Also, for standard images that possess local and approximate self‐similarity fractal characteristics, although the measured SNR performance is lower, the proposed functional sets are shown to provide excellent subjective performance and to preserve the fractal properties of the images. On the other hand, for standard images that do not possess these fractal properties, compression errors are apparent in blocks from both smooth and edge regions of the images.
An estimation of acoustic parameters of piezoelectric telephone by Monte Carlo method
Authors: Kajikawa Yoshinobu , Nomura Yasuo , Ohga Juro 
Published: July 2007

AbstractA problem in the telephone handset is that there is no design formula that can relate the values of the parameters in the acoustic equivalent circuit (acoustic parameters) of the earphone system directly to the shape (dimensions) of the actual handset. As a result, the design of the handset has been made very difficult. to derive such a formula, the values of the acoustic parameters must be estimated accurately from the actual measurement of the handset.Previously, the authors have estimated that acoustic parameters, using the nonlinear optimizatoin technique, but a problem is still left that the number of parameters that can be simultaneously estimated is limited. This paper tries to solve this problem and proposes and estimation technique using the Monte Carlo method, which can also realize a high estimation accuracy. In the proposed method, an allowable range for the actual response is defined and the acoustic parameters are estimated by modifying the upper and the lower limits of each acoustic parameter so that the response stays within the allowable range.The proposed method has the advantages that the number of parameters to be estimated is not limited, a good agreement can be realized with the actual response, and the decision can be made without intuition. the approach also provides a useful means for the design of the whole system. Although this paper discusses the estimation for the piezoelectric telephone handset, the proposed method can be applied effectively to any type of telephone handset.
An equivalent model for subband adaptive system and analysis of its performance
Authors: Ono Yoshihiro , Nishikawa Kiyoshi , Kiya Hitoshi 
Published: July 2007

AbstractIt is well known that the subband adaptive system is useful; however, the study of the theoretical analysis of the system does not seem sufficient. the theoretical analysis is problematic because of the structural constraint in which the input to the unknown system is not the same as the input to the adaptive filter. This paper attempts theoretical analysis of the subband adaptive system and proposes a new equivalent model that removes the foregoing constraint. Then the theory of the Wiener filter is applied to the equivalent model. the optimal ADF coefficient and the least‐mean‐square error (LMSE) in the subband adaptive system are theoretically derived. Lastly, the derived theoretical value is compared to the results of the experiment and the effectiveness of the proposed model and the theoretical expression are demonstated.
Acceptance and generation of general wave by a natural observation filter
Authors: Iijima Taizo 
Published: July 2007

AbstractDuring the past few years, there has been a series of papers published on the theory of the natural observation method. As one of the important applications of this theory, the problems of acceptance and generation of a general waveform are discussed here. The case of polynomial waveforms and its corresponding theory was published previously. A great extension of that theory which covers general waveforms is presented here and its full picture is clarified.
Evaluation of block error probability of trellis codes
Authors: Yamamoto Hiroshi , Fujiwara Toru , Takata Toyoo , Kasami Tadao 
Published: July 2007

AbstractAn efficient method is proposed to evaluate the block error probability of trellis codes. the notion of correct state on the most likely paths in Viterbi decoding on additive white Gaussian noise (AWGN) channels is introduced. the probability that a state is correct and the probability that the state following a correct state is also correct are evaluated by simulation. These probabilities do not depend on block length. Then the block error probability for any given block length is estimated by simple calculation from the forementioned probabilities.This method is applied for some specific 8‐PSK Ungerboeck codes with 24, 25, and 26 states. the results show that the values obtained by this method are very close to those by simulation. It is concluded that this method is very effective.
An intelligent digital signal processing system for stock trends based upon transient wave detection by using gabor representation and knowledge representation of waveforms
Authors: Tokinaga Shozo , Ishida Yasuyuki 
Published: July 2007

AbstractThis paper considers the realization of an intelligent digital signal processing system for representing time series and its applicatio to the classification of stock prices. the system utilizes an effective mechanism to detect the nonstationary part (transient waves) which includes important information on the time series based on the Gabor representation and the knowledge representatio of waveforms using an expert system. In the subsystem for digital signal processing, an adaptive ARMA model is fitted to the time series obtained by subtracting the moving average from the original time series to generate the time series containing enhanced transient waves.The Gabor representation is applid to classify the kinds of transient waves. A set of codebooks for the spectrum of transient waves is used to identify the kind of transient wave. In the subsystem of the expert system, the characteristics of the time series obtained by digital signal processing and other features recognized by conventional methods such as trend lines are transferred to the frames so that the recognition rules of experts are applied to classify the time series. As an application, 194 time series of stock prices are recognized and classified into 11 categories.The result shows that about 80 percent of the times series is recognized, and categories which are close to the original ones are included as the candidates.
An adaptive unidirectional linear response fuzzy controller based on reinforcement learning
Authors: Tang Zheng , Komori Masakazu , Ishizuka Okihiko , Tanno Koichi 
Published: July 2007

AbstractThis paper presents an adaptive fuzzy controller using unidirectional linear response (ULR) elements. The basic functions for a fuzzy controller including membership, minimum and defuzzification functions are realized by the ULR elements. Because the ULR element has diode‐like characteristics, it can be implemented by a diode‐connected mean‐opinion score (MOS) transistor in current‐mode implementations. The hardware implementation of the fuzzy controller using ULR elements should also be very simple and straightforward. The ULR fuzzy controller is applied to an inverted pendulum problem, and the effectiveness of the proposed ULR controller architecture and its learning capability based on reinforcement learning are demonstrated.
Approximation bounds of three‐layered neural networks—a theorem on an integral transform with ridge functions
Authors: Murata Noboru 
Published: July 2007

AbstractNeural networks have attracted attention due to their capability to perform nonlinear function approximation. In this paper, in order to better understand this capability, a new theorem on an integral transform was derived by applying ridge functions to neural networks. From the theorem, it is possible to obtain approximation bounds which clarify the quantitative relationship between the function approximation accuracy and the number of nodes in the hidden layer. The theorem indicates that the approximation accuracy depends on the smoothness of the target function. Furthermore, the theorem also shows that this type of approximation method differs from usual methods and is able to escape the so‐called “curse of dimensionality,” in which the approximation accuracy depends strongly of the input dimension of the function and deteriorates exponentially.
An automatic‐repeat request policy for a data transmission system with three types of error probabilities
Authors: Yasui Kazumi , Nakagawa Toshio , Sandoh Hiroaki 
Published: July 2007

AbstractIn the data transmission, in general, the data error is inevitable due to the interference to the communication channel, e.g., temporary disconnection, the noise, and the distortion. Then the error control is indispensable in order to maintain a high quality of data and various methods have been devised from the viewpoint of reliability improvement. Among those, automatic‐repeat request (ARQ) is applied frequently to the point‐to‐point data transmission system, since the error can be controlled relatively simply.This paper assumes that the data error occurs at random, usually in the transmission system; and a transmission model is discussed where the generaton of the error is enhandced greatly by the occurrence of the intermittent faults and their potential period. In other words, it is assumed that the transmission system has three states, i.e., normal, temporary fault, and permanent fault.An ARQ model then is defined in which the error of the unit data arises with different probabilities in those states. When an error occurs, retransmissions are attempted for up to (N ‐ 1) times. If all retransmission trials fail, the transmission of the unit data is restarted from the initial state after the specified period. Using the probability genertive function, the mean time until the transmission of the unit data succeeds is derived. the optimal number N of retransmission trials that minimize the above mean time is determined analytically. Discussions are then made on the result using numerical examples.
Symmetry of periodic solutions of five coupled oscillators in a ring
Authors: Katsuta Yuuji , Kawakami Hiroshi 
Published: July 2007

AbstractThis paper considers the oscillators coupled in the form of a ring through resistors. It is described for the case of five oscillators that, for the symmetrical solutions, the analysis based on the conjugate class in group theory is useful. Major problems in the coupled oscillators are the existence of the synchronized periodic solution and its stability. In the case of the weakly nonlinear system, the problems of the synchronized periodic solution and the stability are almost answered by techniques that include mode analysis. In the case of the strongly nonlinear system, on the other hand, the periodic solutions with symmetry have been classified mostly based on the subgroup in the group theory when the number of coupled oscillators is less. When the number of oscillators is increased, however, the number of subgroups becomes tremendous, which makes systematic analysis difficult. This paper uses the conjugate class and shows that the symmetrical solutions can be classified systematically. It is also shown that the approximate periodic solution with symmetry can be approximately determined by the averaging based on the symmetry.
Wideband beamforming by means of band division
Authors: Taniguchi Tetsuki , Nishikawa Kiyoshi , Miyaki Akira 
Published: July 2007

AbstractThis paper describes a method that realizes wideband beamforming efficiently. In the proposed method, the band‐division processing is applied where the signal received from the array sensor is divided into the low‐and high‐frequency components and the fan‐filter with the wedge‐shaped transition region and an adequate order is applied to each of the divided bands. the mid‐point of the band is defined as the stopband edge of the lower band filter for dividing the band so that one‐half lowspeed processing is applied to the lower band and the lower‐band fan filter is realized by a lower order. the upper‐band fan filter is designed efficiently by including the high‐pass filter for the band division.A design example is presented, and it is shown that both the computational complexity and the number of sensors are considerably reduced compared to the case of the direct design. In other words, it is shown that the band division is effective.
A hierarchical IFS image coding with the gaussian pyramid
Authors: Nakano Katsuhiko , Nakagawa Masahiro 
Published: July 2007

AbstractA novel IFS coding scheme is proposed for image compression. the present method is based on hierarchical structure or the Gaussian pyramid of contracted images. In comparison with the conventional scheme (IFS or JPEG), the presently introduced hierarchical scheme is found to be useful, especially for relatively low‐bit rates. This is considered to be as a result of the subband division of the original image and the existence of the redundancy between the range and domain characteristics in the image. On the basis of the present scheme, it is found that the bit rate may be reduced up to the conventional scheme with the transform coding scheme, for the original monochrome image with 256×256 size and 8‐bit gray‐scale levels.
Predicting chaotic sequences in a blast furnace by a generalized radial basis function network
Authors: Miyano Takaya , Shibuta Hiroshi , Nakashima Ken , Ikenaga Yasuharu 
Published: July 2007

AbstractNonlinear forecasting is applied to characterize the complexities in time series of temperature fluctuations and pressure fluctuations observed in a blast furnace. A generalized radial basis function network and a Sugihara‐May predictor are used as the predictive models. the temperature sequence may be diagnosed as low‐dimensional chaos according to the scaling property of the prediction error as a function of the prediction‐time interval. Short‐term forecasts about the temperature sequence are successfully made by the network that has learned the underlying dynamics embedded in three‐dimensional delayed space.