Electronics and Communications in Japan (Part III: Fundamental Electronic Science)最新文献_第3页

Neuro‐hardware for peak power reduction of oversampled OFDM signal 过采样OFDM信号峰值功率降低的神经硬件

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-08-01 DOI: 10.1002/ECJC.20285

A. Mori, M. Ohta, K. Yamashita

引用次数: 3

Secret information distribution 秘密信息分发

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-08-01 DOI: 10.1002/ECJC.20308

M. Okamoto, Y. Tanaka

引用次数: 2

Characterization of sonochemical reactors by chemical dosimetry 用化学剂量法表征声化学反应器

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-08-01 DOI: 10.1002/ECJC.20315

Y. Asakura, M. Maebayashi, T. Matsuoka, S. Koda

{"title":"Characterization of sonochemical reactors by chemical dosimetry","authors":"Y. Asakura, M. Maebayashi, T. Matsuoka, S. Koda","doi":"10.1002/ECJC.20315","DOIUrl":"https://doi.org/10.1002/ECJC.20315","url":null,"abstract":"Irradiation of ultrasonic waves induces cavitation in a solution, and a chemical action instigated by radicals occurs. This chemical action is reported to be most efficient in the region of several hundred kilohertz frequencies. Application of sonochemistry based on ultrasonic chemical action remains at the laboratory scale and has not yet reached the industrial practical scale. In order to realize practical applications of sonochemistry, there is a need to scale-up the sonochemical reactors. For this purpose, we used a 490-kHz cylindrical sonochemical reactor that is long in the irradiation direction, and used potassium iodide (KI) dosimetry, sonochemical luminescence, and calorimetry to evaluate the sonochemical reaction efficiency and reaction field of the reactor. We performed the evaluation with the ultrasonic irradiation direction in the horizontal and vertical directions. As a result, we observed sonochemical luminescence and a rise in temperature near the reflection surface, for both the horizontal and vertical irradiation. For the horizontal irradiation, the I3− concentration was evenly distributed in the irradiation direction. Moreover, we found that the sonochemical reaction efficiency was the same for both the horizontal irradiation and the vertical irradiation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(8): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20315","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74126403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Utilizing nonlinear behavior of microbubbles in medical ultrasound 微泡非线性特性在医学超声中的应用

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-08-01 DOI: 10.1002/ECJC.20259

S. Umemura, K. Kawabata, K. Sasaki

引用次数: 4

A method of detection of signals corrupted by nonstationary random noise via stationarization of the data 一种通过对数据进行平稳化来检测被非平稳随机噪声破坏的信号的方法

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-08-01 DOI: 10.1002/ECJC.20302

H. Ijima, A. Ohsumi, R. Okui

{"title":"A method of detection of signals corrupted by nonstationary random noise via stationarization of the data","authors":"H. Ijima, A. Ohsumi, R. Okui","doi":"10.1002/ECJC.20302","DOIUrl":"https://doi.org/10.1002/ECJC.20302","url":null,"abstract":"This paper proposes a method for detecting a signal embedded in nonstationary noise. In most past studies of the signal detection problem, random noise is considered as a stationary stochastic process, since it is mathematically easy to handle. However, the noise observed in practice contains many nonstationary elements with time-varying (evolutionary) statistical properties. In this study, observational noise is modeled as a probability density function with slowly evolving parameters. Then, based on the evolving spectral representation, the nonstationary observation data are transformed to a stationary process. A new method is proposed as follows. It is assumed that nonstationarity remains in the stationarized observation data in the interval containing the signal, due to the effect of the signal. Then the signal is detected by testing for stationarity. In the proposed method, Priestley's evolutionary spectrum is used in the spectral representation of the nonstationary stochastic process, and the method of Okabe and colleagues based on the KM2O-Langevin equation is used for the stationarity test. The effectiveness of the proposed method is verified by a simulation experiment. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(8): 29–38, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20302","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85744283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Performance analysis of UWB impulse radar receiver using parallel IPCP 基于并行IPCP的超宽带脉冲雷达接收机性能分析

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-07-01 DOI: 10.1002/ECJC.20303

Hiroyuki Hatano, T. Yamazato, Hiraku Okada, M. Katayama

{"title":"Performance analysis of UWB impulse radar receiver using parallel IPCP","authors":"Hiroyuki Hatano, T. Yamazato, Hiraku Okada, M. Katayama","doi":"10.1002/ECJC.20303","DOIUrl":"https://doi.org/10.1002/ECJC.20303","url":null,"abstract":"This paper considers a vehicle-borne target detection system for short range in which an UWB (Ultra Wideband) impulse radar is used. The UWB impulse radar uses a pulse with widths of less than nanosecond order. Therefore, many multipath returns are observed on the receiving side. An IPCP (Inter-Period Correction Processing) receiver that resolves complexity of the receiver caused by multiple paths has been proposed. However, the integration time of the correlator in the IPCP receiver is limited by the period of the transmission signal (code length) and affects the range measurement accuracy. This paper considers vehicle mounting for applications. In order to assure safety, a receiver is constructed with several IPCP receivers in parallel, so that the range measurement accuracy is improved. In addition, a receiver which reduces the complexity of threshold setting in the conventional IPCP receiver when several targets are detected is proposed. The outputs of these receivers are derived analytically and improvement of the range measurement accuracy is confirmed. Further, based on the analytical results, the output of each receiver is characterized and the relationship of the threshold, detection probability, and false error probability is derived. Finally, the characteristics of use of the receiver as a vehicle-mounted radar are evaluated by simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 1–14, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20303","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80400794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

FFT‐based fast conjugate gradient method for real‐time dereverberation system 基于FFT的快速共轭梯度实时去噪方法

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-07-01 DOI: 10.1002/ECJC.20292

K. Furuya, A. Kataoka

{"title":"FFT‐based fast conjugate gradient method for real‐time dereverberation system","authors":"K. Furuya, A. Kataoka","doi":"10.1002/ECJC.20292","DOIUrl":"https://doi.org/10.1002/ECJC.20292","url":null,"abstract":"When speech at a location away from a microphone is received, the received speech is degraded by reverberation in a room. To deal with this problem, a semiblind dereverberation method has been proposed in which no prior measurement of the room impulse response is used. However, the fast computation was required because an enormous amount of computation is needed for inverse filter calculation. In this paper, an acceleration method for the inverse filter calculation in the semiblind dereverberation method is proposed. For speed enhancement, the similarity of the correlation matrix to the convolution matrix is considered. By using fast convolution by the FFT in the conjugate gradient method, a dramatic increase in computation speed is achieved. A real-time dereverberation system was constructed on a personal computer by installing the proposed method and was tested in an actual environment. It was confirmed that the proposed method can achieve high-speed operation without degradation of dereverberation performance. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 25–36, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20292","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77768222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Noise removal for degraded images by IBS shrink method in multiwavelet domain 多小波域IBS收缩法对退化图像的去噪

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-07-01 DOI: 10.1002/ECJC.20295

Jianming Lu, Ling Wang, Yeqiu Li, T. Yahagi

{"title":"Noise removal for degraded images by IBS shrink method in multiwavelet domain","authors":"Jianming Lu, Ling Wang, Yeqiu Li, T. Yahagi","doi":"10.1002/ECJC.20295","DOIUrl":"https://doi.org/10.1002/ECJC.20295","url":null,"abstract":"The wavelet transform has been used for image compression, image restoration, signal processing, and pattern recognition. In most cases, processing is performed with a scalar wavelet using one scaling function. However, the scalar wavelet has the deficiency that the properties of shortness of support, regularity, orthogonality, and high vanishing moment are not shared at the same time. Recently, the multiwavelet, consisting of several scaling functions and several wavelet functions, has been proposed. Since several input data are obtained by preprocessing in the multiwavelet transform, many studies of applications of the multiwavelet in the fields of signal processing and image processing are being carried out. Many engineering achievements have been reported. However, little has been reported on the use of multiwavelets for restoration of degraded images. This is a research field with prospects for future growth. In the present research, a threshold shrinking method is proposed in which different threshold values are used for the horizontal, vertical, and diagonal directions at each level and also within the same level in the multiwavelet domain for degraded images with superimposed Gaussian noise. The effectiveness of the proposed method is demonstrated by a computer simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 15– 24, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20295","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90601636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

A data hiding method for JPEG 2000 coded images using modulo arithmetic 基于模算法的jpeg2000编码图像的数据隐藏方法

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-07-01 DOI: 10.1002/ECJC.20286

H. Jin, M. Fujiyoshi, Yusuke Seki, H. Kiya

引用次数: 5

Signed Power-of-Two Expression for Multipliers of Lifting Wavelet for Image Compression 图像压缩提升小波乘子的有符号二幂表达式

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-07-01 DOI: 10.1002/ECJC.20272

Y. Tonomura, M. Iwahashi, T. Tsubone, N. Kambayashi

{"title":"Signed Power-of-Two Expression for Multipliers of Lifting Wavelet for Image Compression","authors":"Y. Tonomura, M. Iwahashi, T. Tsubone, N. Kambayashi","doi":"10.1002/ECJC.20272","DOIUrl":"https://doi.org/10.1002/ECJC.20272","url":null,"abstract":"For image compression, frequency conversions such as the discrete cosine transform (DCT) and the wavelet transform (DWT) have been widely used. The multiplier coefficients used in these conversions are in general defined as real numbers, but they are approximated by a finite word length in the hardware configuration. This causes degradation of the reconstructed images due to mismatch of the coefficient values for the forward and backward transforms. In order to reduce the degradation of the reconstructed images caused by coefficient mismatch, a sufficiently long word length can be provided in setting the finite word length. However, since the compressed image data undergo quantization processing prior to entropy encoding in general, a word length greater than a certain length causes redundancy. Hence, this paper proposes a method in which the coefficient values of each multiplier are provided by the signed power-of-two (SPT) representation, using a sum of powers of 2 with as small a (finite) number of terms as possible, so that the error caused by coefficient mismatch is smaller than the error caused by quantization. In this way, a minimum-size wavelet circuit can be constructed in which the effect of coefficient mismatch between the forward and backward transformations cannot be visually recognized. It was experimentally confirmed by an experiment using the HDL language that the size of the circuit configuration used in the proposed method could be reduced by about 50% in comparison with the circuit in which the sum of the same number of powers of 2 is assigned to each multiplier coefficient. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 47– 57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20272","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85366744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0