bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blind adaptive detection using differential CMA for CDMA systems
Authors: Miyajima Teruyuki 
Published: October 2004

AbstractIn this paper, we consider the application of adaptive linear filters adjusted by stochastic gradient algorithms to the suppression of multiple‐access interference in DS/CDMA communications. It is pointed out that the linearly constrained constant modulus algorithm (LCCMA) cannot converge to the optimum point if the desired user magnitude is less than a critical value. Next, we propose to use the linearly constrained differential constant modulus algorithm (LCDCMA), and show that the LCDCMA always converges to the optimum point regardless of the desired user magnitude. Several simulation results show the following three points. First, the LCDCMA provides better performance than existing algorithms because the variance of the weight vector adjusted by the LCDCMA is less than that by existing algorithms. Second, the LCDCMA is relatively insensitive to the estimation error of the desired signal vector. Third, the LCDCMA combined with a blind channel estimation algorithm is useful. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(1): 1–13, 2002
Investigation of not‐in‐phase synchronization on coupled system of four oscillators
Authors: Sekiya Hiroo , Yoshinaga Tetsuya , Moro Seiichiro , Mori Shinsaku , Sasase Iwao 
Published: October 2004

AbstractRecently, synchronization phenomena on four three‐dimensional chaotic oscillators full‐coupled by capacitors have been investigated. In this system, four‐phase synchronization can be observed. Four‐phase synchronization means that a pair of anti‐phase synchronizations are locked at 90°, and are never observed in the coupled system of van der Pol oscillators. However, there has been no theoretical discussion of the conditions for generating a locked pair of anti‐phase synchronizations, such as four‐phase synchronization on coupled identical oscillators. In this paper, we give the necessary and sufficient conditions for generating an independent pair of anti‐phase synchronizations in the coupled system of four oscillators with odd functions as nonlinear characteristics. The systems that do not satisfy the conditions generate a locked pair of anti‐phase synchronizations. Therefore, it is the first theoretical clarification of generating a locked pair of anti‐phase synchronizations. We investigate the synchronization phenomena on the coupled system of three‐dimensional oscillators and indicate the validity of the necessary and sufficient conditions. When each oscillator oscillates with direct components, when there are variables having direct components in the coupling terms, and when direct components of oscillations synchronized at anti‐phase are equal in amplitude, the system loses symmetry, which is the condition for generating an independent pair of anti‐phase synchronizations. Carrying out numerical calculations, we confirm the generation of four‐phase synchronization and in‐ and anti‐phase synchronization. In particular, generation of stable in‐ and anti‐phase synchronization is the first observation. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(2): 1–12, 2002
Wavelet‐based image coding using all‐pass filters
Authors: Kamimura Seiya , Zhang Xi , Yoshikawa Toshinori 
Published: October 2004

AbstractFIR wavelet filters are mainly used in conventional wavelet‐based image coding. However, FIR filters, except for the Haar wavelet, cannot satisfy both the exactly linear phase and orthonormality conditions. For example, the well‐known Daubechies‐9/7 wavelet is biorthogonal. In this paper, an effective implementation of the all‐pass‐based wavelet filters is presented for wavelet‐based image coding. Since all‐pass filters are IIR, both the exactly linear phase and orthonormality conditions can be simultaneously satisfied, so that better compression performance can be expected. Also, IIR filters can be realized with a lower computational complexity than can FIR filters. Finally, the proposed IIR wavelet filters are evaluated by using SPIHT to compress the practical images, and the influence of the all‐pass filters and delay elements on the compression performance is investigated. It is shown through the experimental results that the IIR wavelet filters proposed in this paper have a lower computational complexity than the Daubechies‐9/7 wavelet, with a comparable compression performance. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(2): 13–21, 2002
A realization of oversampled cosine modulated filter banks with perfect reconstruction
Authors: Itami Fumio , Watanabe Eiji , Nishihara Akinori , Yanagisawa Takeshi 
Published: October 2004

AbstractIn the design of filter banks, the cosine‐modulated filter bank (CMFB) has drawn attention due to reduced computational overhead and case of design. In the conventional design method for a linear‐phase CMFB, delay elements are added to the transfer function in order to realize the paraunitary property. Therefore, the polyphase structure carries out the rate transformation in two steps and the computation of the prototype filter is executed in a form where the rate is not completely reduced. Hence, the scheme is not optimum in terms of the computational overhead per unit time. Also, the splitting shape of the linear‐phase split filter is a special one and is not equally split. In consideration of the above, a new method of realization is considered in this paper for an oversampled linear‐phase CMFB. In its realization, reduction of the overall computation overhead is considered. At the same time, a transfer function with an equally split shape is presented. From the proposed transfer function, a polyphase structure is derived in which the computation is possible with a completely reduced rate for an arbitrary integer sampling. In realization of the perfect reconstruction, a method is proposed in which the paraunitary property is removed and the synthesis side can be constructed with a small amount of computation. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(2): 32–42, 2002
Optimal Backup Policies for a Database System with Incremental Backup
Authors: Qian Cunhua , Nakamura Syouji , Nakagawa Toshio 
Published: October 2004

AbstractWhen the data of a database are frequently updated, the operation of incremental or cumulative backup is usually adopted so as to make the backup copies efficiently. Such backups are suitably executed between the operations of complete backup for most mass database systems. This paper considers three backup policies for two schemes of export backup in a database system: The reliability measures of these policies are derived, using the theory of cumulative processes. Comparisons between two schemes of export backup are made. Specifically, an optimal backup scheme and an optimal time of a full backup are discussed. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(4): 1–9, 2002
A Method for Changing Sound‐Image Position Using the Linear Loudspeaker Array and Two‐Dimensional FIR Digital Filter
Authors: Nishikawa Kiyoshi , Yokoyama Tetsuya , Miyagishi Mikiko 
Published: October 2004

AbstractIn this paper, the problem of sound‐image control is considered as that of wave front shape of the acoustic beam radiated from a speaker array. A method is proposed for realizing the sound‐image control in an acoustic beam by providing the necessary delay characteristics to a two‐dimensional FIR filter as the group delay. The filter design is carried out by means of a two‐dimensional Fourier series approximation in which the fan‐shaped passband amplitude is specified for formation of the radiation pattern in addition to the required group delay. It is found that the degree of approximation in the filter design can be improved substantially by making the radius of the circle set for modification infinite. Further, the center of the circle forms a focal point as in an optical system and this point becomes a virtual sound source and hence the position of the sound image. The wave is expanding in a manner of concentric circles from this point. The width of the acoustic beam generated from this sound image is determined by the spread of the speaker array and the position of the sound image. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(4): 20–31, 2002
Approximation of multiplicatively weighted crystal growth Voronoi diagram and its application
Authors: Kobayashi Kei , Sugihara Kokichi 
Published: October 2004

AbstractA multiplicatively weighted crystal growth Voronoi diagram is a type of planar segmentation diagram that can result when crystals grow at different speeds from several points. In this paper, we first define a multiplicatively weighted crystal growth Voronoi diagram, discuss its properties, and find the analytic solution for the simple case. The approximate solution method for the complex case is constructed by using a difference method for partial differential equations called the fast marching method. Then the multiplicatively weighted crystal growth Voronoi diagram is used to construct a technique for optimum path planning of competing mobile robots. © 2002 Scripta Technica, Electron Comm Jpn Pt 3, 85(6): 21–31, 2002
A novel slip‐power recovery system using a PWM boost rectifier
Authors: Hoshi Nobukazu , Oguchi Kuniomi 
Published: October 2004

AbstractA novel compact slip‐power recovery system having sinusoidal rotor currents is proposed. In this system, a PWM boost rectifier is used as a substitute for a diode rectifier and a boost chopper in a conventional compact slip‐power recovery system. The conventional compact system has the disadvantage that it has a rectangular rotor current, and a motor torque with large ripple, because a diode rectifier remains in the system. Also, the rotor current cannot reach the current reference value near the synchronous speed, because the voltage drop caused by the resistance of the semiconductor devices and so on cannot be neglected when the rotor voltage becomes smaller near the synchronous speed. The use of the system proposed in this paper has solved these problems. The effectiveness of the proposed system was verified through computer simulations and experiments. As a result, the proposed system brings the sinusoidal rotor current, the small torque ripple, and wide controllable range near the synchronous speed. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 52–60, 2002; DOI 10.1002/eej.10012
Electronic and optical properties of liquid‐crystalline poly(p‐phenylene vinylene) derivatives and their functional application
Authors: Onoda Mitsuyoshi , Tada Kazuya , Ozaki Masanori , Yoshino Katsumi 
Published: October 2004

AbstractPoly(2‐methoxy, 5‐(4‐decyloxy‐biphenyl‐4‐′(1,10‐dioxydecane))‐p‐phenylene vinylene), MDBD‐PPV, with a long side chain containing alkoxybiphenyl mesogenic unit has been synthesized and its electrical and optical properties have been investigated. This polymer showed a microscopic texture typical to the liquid‐crystalline phase and a sharp X‐ray diffraction peak due to the smectic layer structure. The band gap of MDBD‐PPV in the liquid‐crystalline phase has been estimated to be about 2.3 eV. An electroluminescent (EL) device has been fabricated using this liquid‐crystalline polymer, MDBD‐PPV, as an emissive layer and the polarity effect has been observed in the emission spectra of this EL device. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 1–8, 2002
Numerical analysis of effects of electric field and pulse duration on discharge DeNOx performance
Authors: Ito Kohei , Hagiwara Katuyuki , Nakaura Hiroyuki , Onda Kazuo , Tanaka Hidekazu 
Published: October 2004

AbstractBy virtue of its comparatively high denitrification (deNOx) efficiency and its compactness, the pulsed‐discharge deNOx process is considered to be one of the deNOx processes suitable for combustion gas. However, there has been insufficient clear guidance on the optimum electric field, pulse duration, and pulse repetition frequency, and no clear understanding of pulsed‐discharge deNOx process. In this study, we have simulated the pulsed‐discharge deNOx process by solving the Boltzmann equation for discharge electrons and the deNOx chemical reaction equations simultaneously, and we have shown the time change of chemical species concentration, extracting the main deNOx reactions. The simulation shows that the pulsed‐discharge deNOx process consists of two processes, the reduction of NO to N2 by N radicals and the oxidation of NO to HNO3 and HNO2 by OH and O radicals, and that the amounts of radicals produced and consumed are governed by parameters such as the electric field, pulse duration, and pulse repetition frequency. In our simulation, such parameters are varied widely to examine their quantitative effect on the deNOx energy consumption, NxOy removal efficiency, and reduction ratio in the discharge deNOx process. The preliminary pulsed‐discharge deNOx performance is estimated from our simulation, indicating that the discharge deNOx process has almost the same performance as the electron‐beam deNOx process. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 1–11, 2002; DOI 10.1002/eej.1149
A data mining method for short‐term load forecasting in power systems
Authors: Mori Hiroyuki , Kosemura Noriyuki 
Published: October 2004

AbstractThis paper proposes a method for daily maximum load forecasting in power systems. It is based on the integration of the regression tree and the artificial neural network. In this paper, the regression tree is used to extract knowledge or rules as a data‐mining method. That is useful for the information processing of the complicated data. As a result, the proposed method has an advantage in clarifying the cause and effect of dynamic load behavior in load forecasting. However, the regression tree does not necessarily yield good prediction results in spite of good classification. Therefore, this paper proposes a method for combining the classification results of the regression tree with the multilayer perceptron of a universal nonlinear approximator. The effectiveness of the proposed method is demonstrated in real data. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 12–22, 2002; DOI 10.1002/eej.1150
Influences of the inclination of gratings on the alignment accuracies in moiré alignment systems
Authors: Furuhashi Hideo , Zhou Lizhong , Liu Jingnan , Matsuo Akihito , Uchida Yoshiyuki 
Published: October 2004

AbstractIn the lithographic processes of VLSIs, high setting accuracies between masks and wafer are required. The methods using moiré signals obtained by gratings were found to give very high alignment accuracies. In this paper, influences of the inclination of gratings for the alignment accuracies in modified and differential moiré systems have been investigated. The moiré signals and the alignment point have been calculated using computer simulation. As a result, it has been shown that the effects are small and the inclinations do not affect alignment accuracies in the moiré alignment systems. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 46–51, 2002; DOI 10.1002/eej.1152
Measurement of the source impedance of conducted emission using mode separable LISN: Conducted emission of a switching power supply
Authors: Miyashita Junichi , Mitsuzawa Masayuki , Karube Toshiyuki , Yamasawa Kiyohito , Sato Toshiro 
Published: October 2004

AbstractIn the procedure for reducing conducted emissions, it is helpful to know the noise source impedance. This paper presents a method of measuring noise source complex impedances of common and differential mode separately. We propose a line impedance stabilization network (LISN) to measure common and differential mode noise separately without changing LISN impedances of each mode. With this LISN, conducted emissions of each mode are measured inserting appropriate impedances at the equipment under test (EUT) terminal of the LISN. Noise source complex impedances of switching power supply are well calculated from measured results. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 72–78, 2002; DOI 10.1002/eej1154
On the enhanced convergence of standard lattice methods for option pricing
Authors: Widdicks Martin , Andricopoulos Ari D. , Newton David P. , Duck Peter W. 
Published: October 2004

AbstractFor derivative securities that must be valued by numerical techniques, the trade‐off between accuracy
and computation time can be a severe limitation. For standard lattice methods, improvements are achievable by
modifying the underlying structure of these lattices; however, convergence usually remains
non‐monotonic. In an alternative approach of general application, it is shown how to use standard
methods, such as Cox, Ross, and Rubinstein (CRR), trinomial trees, or finite differences, to produce
uniformly converging numerical results suitable for straightforward extrapolation. The concept of Λ, a
normalized distance between the strike price and the node above, is introduced, which has wide ranging
significance. Accuracy is improved enormously with computation times reduced, often by orders of magnitude.
© 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:315–338, 2002
Investor Sentiment and Return Predictability in Agricultural Futures Markets
Authors: Wang Changyun 
Published: October 2004

AbstractThis study examines the usefulness of trader‐position‐based sentiment index for forecasting
future prices in six major agricultural futures markets. It has been found that large speculator sentiment
forecasts price continuations. In contrast, large hedger sentiment predicts price reversals. Small trader
sentiment hardly forecasts future market movements. An investigation was performed into various
sentiment‐based timing strategies, and it was found that the combination of extreme large trader
sentiments provides the strongest timing signal. These results are generally consistent with the
hedging‐pressure theory, suggesting that hedgers pay risk premiums to transfer nonmarketable risks in
futures markets. Moreover, it does not appear that large speculators in the futures markets possess any superior
forecasting ability. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:929–952, 2001
Chromosomal alterations during metastasis formation of head and neck squamous cell carcinoma
Authors: Bockmühl Ulrike , Schlüns Karsten , Schmidt Sven , Matthias Sabine , Petersen Iver 
Published: October 2004

AbstractComparative genomic hybridization (CGH) was used to detect chromosomal changes during metastasis formation of head and neck squamous cell carcinomas (HNSCCs). In total, 92 tumors of 54 patients were investigated. In 34 of these, the metastases were compared to the corresponding primary tumors. The group of metastatic tumors was also compared with 20 nonmetastatic tumors. Gain of 3q was the earliest genetic marker for invasion and metastasis and also correlated with poor prognosis. Additional metastasis‐associated lesions were gains on 11q13, 7q11.2, 1q21‐q22, and losses on 8p, 11p14, 11q14‐qter, 10p12, 10q, and 14q. The incidence of the chromosomal changes was used to evaluate their significance and temporal order of appearance during tumor dissemination, thus leading to an extended progression model of HNSCC. In the clonality analysis, three different methods revealed a mean concordance of 64 and 68% between pairs of primaries and metastases, respectively. Using different similarity scores, the correct metastasis was identified from the pool of all metastatic lesions in 19–26 of the 34 cases. The study supplements previous genetic results on HNSCC pathogenesis and provides criteria for multiple tumor analysis.
Tree‐based recursive partitioning methods for subdividing sibpairs into relatively more homogeneous subgroups
Authors: Shannon William D. , Province Michael A. , Rao D.C. 
Published: October 2004

AbstractWe propose a new splitting rule for recursively partitioning sibpair data into relatively more homogeneous subgroups. This strategy is designed to identify subgroups of sibpairs such that within‐subgroup analyses result in increased power to detect linkage using Haseman‐Elston regression. We assume that the subgroups can be defined by patterns of non‐genetic binary covariates measured on each sibpair. The data we consider consists of the squared difference of a quantitative trait measurement on each sibpair, estimates of identity‐by‐descent (IBD) values at each genetic marker, and binary covariate data describing characteristics of the sibpair (e.g., race, sex, family history of disease). To test the efficacy of this method in linkage analysis, we performed two simulation experiments. In the first, we simulated a mixture consisting of 66.6% of the sibpairs with no linkage and 33.3% of the sibpairs with genetic linkage to one marker. The two groups were distinguished by the value of a single binary covariate. We also simulated one unlinked marker and one random covariate to include as noise in the data. In the second experiment, we simulated a mixture consisting of 55% of the sibpairs with no genetic linkage, 22.5% of the sibpairs with genetic linkage to one marker, and 22.5% of the sibpairs with linkage to a different marker. Each subgroup was defined by a distinct pattern of two binary covariates. We also simulated one unlinked marker and two random covariates to include as noise in the data. Our simulation studies found that we can significantly increase the overall power to detect linkage by fitting Haseman‐Elston regression models to homogeneous subgroups with only a small increase in the false‐positive rate. Second, the splitting rule can correctly identify important covariates and linked markers. Third, recursive partitioning of sibpair data using this splitting rule can correctly identify sibpair subgroups. These results indicate that partitioning sibpairs into homogeneous subgroups is feasible and significantly increases the power to detect linkage, thus demonstrating the practical utility and potential this new methodology holds. Genet. Epidemiol. 20:293–306, 2001. © 2001 Wiley‐Liss, Inc.
Estimation of allele frequencies with data on sibships
Authors: Broman Karl W. 
Published: October 2004

AbstractAllele frequencies are generally estimated with data on a set of unrelated individuals. In genetic studies of late‐onset diseases, the founding individuals in pedigrees are often not available, and so one is confronted with the problem of estimating allele frequencies with data on related individuals. We focus on sibpairs and sibships, and compare the efficiency of four methods for estimating allele frequencies in this situation: (1) use the data for one individual from each sibship; (2) use the data for all individuals, ignoring their relationships; (3) use the data for all individuals, taking proper account of their relationships, considering a single marker at a time; and (4) use the data for all individuals, taking proper account of their relationships, considering a set of linked markers simultaneously. We derived the variance of estimator 2, and showed that the estimator is unbiased and provides substantial improvement over method 1. We used computer simulation to study the performance of methods 3 and 4, and showed that method 3 provides some improvement over method 2, while method 4 improves little on method 3. Genet. Epidemiol. 20:307–315, 2001. © 2001 Wiley‐Liss, Inc.