Electronics and Communications in Japan (Part III: Fundamental Electronic Science)最新文献_第9页

Phase response of transfer functions and coherent field in a reverberation room 混响室内传递函数与相干场的相位响应

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20293

Yoshinori Takahashi, M. Tohyama, Y. Yamasaki

{"title":"Phase response of transfer functions and coherent field in a reverberation room","authors":"Yoshinori Takahashi, M. Tohyama, Y. Yamasaki","doi":"10.1002/ECJC.20293","DOIUrl":"https://doi.org/10.1002/ECJC.20293","url":null,"abstract":"This paper analyzes the properties of sound field transfer functions that change with the sound source distance (SSD), by measuring reverberant room impulse responses from a point of view of the phase characteristics. We analyzed the propagation phase (PP) according to the SSD in a reverberant field that R. Lyon investigated, by using a narrow-band linear regression analysis of the impulse responses and considered the relation to the zero distribution of the transfer function. As a result, we clarified that the SSD information is included in the phase frequency characteristics of the minimum-phase component and the variances from the PP. The distance from the source where the PP could be observed corresponds to the coherent field based on the wave theory or the critical distance defined by the energy ratio of direct to reverberation sound. Therefore, the field where the PP could be observed in the minimum-phase component of the transfer function can be treated as the direct sound field. In addition, we also present that the reverberation phase (RP) separated and extracted along with PP from the phase frequency characteristics is according to the estimated value from the number of non-minimum-phase zeros. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(4): 1–8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20293","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80683638","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: 6

Warped‐TSP: An acoustic measurement signal robust to background noise and harmonic distortion 翘曲TSP:一种对背景噪声和谐波失真具有鲁棒性的声学测量信号

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20260

M. Morise, T. Irino, Hideki Banno

{"title":"Warped‐TSP: An acoustic measurement signal robust to background noise and harmonic distortion","authors":"M. Morise, T. Irino, Hideki Banno","doi":"10.1002/ECJC.20260","DOIUrl":"https://doi.org/10.1002/ECJC.20260","url":null,"abstract":"TSP (Time-Stretched Pulse, lin-TSP afterwards) and logarithmic TSP (log-TSP) are commonly used in impulse response measurements of audio systems and room acoustics. But the optimal test signal for each environment is different. It is necessary to choose an appropriate test signal for each environment to achieve a better SNR in the measured impulse response. A new acoustic measurement signal that is a hybrid signal of lin-TSP and log-TSP is proposed. The proposed signal, called “warped-TSP,” achieves an SNR higher than that obtained by lin-TSP and log-TSP. It also provides a means to eliminate harmonic distortion due to the reproduction system. In this paper, the definition and features of warped-TSP are introduced in comparison with lin-TSP and log-TSP. We also present the relations between the parameters of warped-TSP, the amplitude frequency characteristics of warped-TSP, and the effects on the representation components due to harmonic distortion. Based on these discussions, a method of selecting the optimal parameters of warped-TSP for a specific measuring environment is given. A series of impulse response measurements performed under different ambient noise conditions revealed that the proposed method outperformed lin-TSP and log-TSP under all conditions in terms of the SNR of the measured impulse response. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(4): 18– 26, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20260","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74608897","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: 14

Hardware decoder for turbo trellis‐coded modulations with higher‐order modulation schemes 高阶调制方案的涡轮栅格编码调制的硬件解码器

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20252

T. Shohon, Kenichi Koshi, M. Tamura, H. Ogiwara

引用次数: 0

Improved spectral subtraction utilizing iterative processing 改进的光谱减法利用迭代处理

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20242

K. Yamashita, S. Ogata, T. Shimamura

{"title":"Improved spectral subtraction utilizing iterative processing","authors":"K. Yamashita, S. Ogata, T. Shimamura","doi":"10.1002/ECJC.20242","DOIUrl":"https://doi.org/10.1002/ECJC.20242","url":null,"abstract":"In this paper, the authors propose a new noise suppression technique that executes iterative processing and sets parameters that are suited for that processing in the spectral subtraction method, which is a noise reduction technique for noise-added speech. Iterative processing is a technique in which speech enhancement processing is executed by considering the estimated speech that is obtained when noise reduction processing is executed once as the input signal again so that a reduction of the residual noise is anticipated. A further reduction of residual noise for which speech degradation is controlled can be achieved by adjusting the parameters for each iteration. The authors also simultaneously propose a technique for maintaining the real-time nature of spectral subtraction when the proposed technique is executed. They use actual speech to which white noise, automobile noise, and crowd babble noise is added to compare the characteristics of the two proposed methods with the conventional spectral subtraction method and its improvements. The authors verified according to objective and subjective evaluations that each proposed technique showed superior results in all noisy environments. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(4): 39 –51, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20242","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86259982","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: 28

On a construction of a nonstabilizer clifford quantum code for 2h(2j+1)‐level states 2h(2j+1)‐能级非稳定clifford量子码的构造

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20222

M. Hagiwara, H. Imai

引用次数: 0

A note on the improvement of a fast correlation attack on stream ciphers 对流密码的快速相关攻击的改进说明

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-04-01 DOI: 10.1002/ECJC.20270

Satoshi Hosobuchi, Tomohiko Saito, T. Matsushima

{"title":"A note on the improvement of a fast correlation attack on stream ciphers","authors":"Satoshi Hosobuchi, Tomohiko Saito, T. Matsushima","doi":"10.1002/ECJC.20270","DOIUrl":"https://doi.org/10.1002/ECJC.20270","url":null,"abstract":"The stream cipher, a type of secret-key cipher, gives the key to a pseudorandom number generator and generates a pseudorandom sequence called the key sequence, and generates the ciphertext sequence taking the exclusive-or of this sequence and the plaintext sequence. A nonlinear combiner generator is a type of pseudorandom number generator used by stream ciphers and is configured from multiple linear-feedback shift registers (LFSRs) and one nonlinear function. A correlation attack is a method for attacking this type of pseudorandom number generator. The correlation between the output sequence of an LFSR and the key sequence is used to estimate the initial state of the LFSR. However, a conventional attack method attacks a single LFSR and is used only to estimate a portion of the multidimensional correlations of the multiple LFSR sequences and the key sequence. Therefore, we propose an algorithm that improves the attack method using the belief propagation (BP) algorithm of Mihaljevic and colleagues and simultaneously attacks multiple LFSRs using the multidimensional correlation. By increasing the information used in the estimation, an improvement in the decoding success rate is expected. In addition, the computational load of the estimation increases, but this increase can be suppressed by an approximation based on the parallel BP algorithm. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(4): 9 – 17, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20270","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81301000","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: 1

FFT-based fast conjugate gradient method for real-time dereverberation system 基于FFT的实时去混响系统快速共轭梯度方法

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-03-28 DOI: 10.1002/ecjc.20292

Ken'ichi Furuya, Akitoshi Kataoka

{"title":"FFT-based fast conjugate gradient method for real-time dereverberation system","authors":"Ken'ichi Furuya, Akitoshi 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":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20292","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71992452","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

Signed power-of-two expression for multipliers of lifting wavelet for image compression 用于图像压缩的提升小波乘法器的两个表达式的符号幂

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-03-28 DOI: 10.1002/ecjc.20272

Yoshihide Tonomura, Masahiro Iwahashi, Tadashi Tsubone, Noriyoshi Kambayashi

{"title":"Signed power-of-two expression for multipliers of lifting wavelet for image compression","authors":"Yoshihide Tonomura, Masahiro Iwahashi, Tadashi Tsubone, Noriyoshi 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":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20272","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71992450","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

Noise removal for degraded images by IBS shrink method in multiwavelet domain 基于多小波域IBS收缩方法的退化图像去噪

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-03-28 DOI: 10.1002/ecjc.20295

Jianming Lu, Ling Wang, Yeqiu Li, Takashi Yahagi

{"title":"Noise removal for degraded images by IBS shrink method in multiwavelet domain","authors":"Jianming Lu, Ling Wang, Yeqiu Li, Takashi 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":"2007-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71992453","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 一种基于模运算的JPEG 2000编码图像数据隐藏方法

Electronics and Communications in Japan (Part III: Fundamental Electronic Science) Pub Date : 2007-03-28 DOI: 10.1002/ecjc.20286

Hong Lin Jin, Masaaki Fujiyoshi, Yusuke Seki, Hitoshi Kiya

引用次数: 5