Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949792
Pei-Jung Chung, J. Böhme
We study the direction of arrival estimation using expectation-maximization (EM) algorithm. The EM algorithm is a general and popular numerical method for finding maximum likelihood estimates which usually has a simple implementation and stable convergence. However, the computational cost caused by the slow convergence of the EM algorithm is still immense for the direction finding problem. Motivated by componentwise convergence of the EM algorithm, we suggest the use of smaller search spaces after a few iterations. In this way, the overall computational cost can be reduced drastically. An adaptive procedure which determines the search spaces involved in the maximization (M) step is proposed. With numerical experiments we demonstrate the improvement of the computational efficiency by using the proposed algorithm.
{"title":"DOA estimation using fast EM algorithm","authors":"Pei-Jung Chung, J. Böhme","doi":"10.1109/ISSPA.2001.949792","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949792","url":null,"abstract":"We study the direction of arrival estimation using expectation-maximization (EM) algorithm. The EM algorithm is a general and popular numerical method for finding maximum likelihood estimates which usually has a simple implementation and stable convergence. However, the computational cost caused by the slow convergence of the EM algorithm is still immense for the direction finding problem. Motivated by componentwise convergence of the EM algorithm, we suggest the use of smaller search spaces after a few iterations. In this way, the overall computational cost can be reduced drastically. An adaptive procedure which determines the search spaces involved in the maximization (M) step is proposed. With numerical experiments we demonstrate the improvement of the computational efficiency by using the proposed algorithm.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126910742","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949790
V. Katkovnik, Yong-Hoon Kim
The windowed linear local polynomial approximation (LPA) of the time-varying direction-of-arrival (DOA) is developed for nonparametric multiple high-resolution estimation and tracking q rapidly moving sources. The method gives estimates of instantaneous values of the directions as well as their first derivatives. The asymptotic variance and bias of these estimates are derived and used for the window size optimization. Marginal beamformers, 2D functions in the /spl theta/ - /spl theta//sup (1)/ space, are proposed in order to be used for estimation and moving sources visualization. These marginal beamformers are able to localize and track every source individually nulling signals from all other moving sources.
{"title":"Localization and tracking of multiple moving sources based on local polynomial approximation of DOA","authors":"V. Katkovnik, Yong-Hoon Kim","doi":"10.1109/ISSPA.2001.949790","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949790","url":null,"abstract":"The windowed linear local polynomial approximation (LPA) of the time-varying direction-of-arrival (DOA) is developed for nonparametric multiple high-resolution estimation and tracking q rapidly moving sources. The method gives estimates of instantaneous values of the directions as well as their first derivatives. The asymptotic variance and bias of these estimates are derived and used for the window size optimization. Marginal beamformers, 2D functions in the /spl theta/ - /spl theta//sup (1)/ space, are proposed in order to be used for estimation and moving sources visualization. These marginal beamformers are able to localize and track every source individually nulling signals from all other moving sources.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127662801","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949819
S. Terachi, Yukio Tanaka
The authors analyzed the electroencephalogram (EEG) time series data of a subject under general anesthesia using a newly devised method proposed by the authors. The analysis revealed an exponential characteristic in power spectral density (PSD) of the EEG, known to be peculiar to nonlinear phenomena. In addition, powers of such frequency components in EEG as alpha, beta, theta and delta were calculated quantitatively by integrating the PSD obtained from the segments of the EEG without any filtering procedures, and their temporal variations were investigated in detail. They were remarkably influenced by the stage of anesthesia. Further, the magnitude of the slope of exponentially decaying PSD increased as anesthesia became effective. The authors therefore proposed to take the magnitude as a new measure of estimating brain activities, and its usefulness was confirmed by the fact that the magnitudes for EEGs of children decrease as ages of subject increase.
{"title":"Detailed study of temporal variations of EEG by improved MEM spectral analysis with high resolution power","authors":"S. Terachi, Yukio Tanaka","doi":"10.1109/ISSPA.2001.949819","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949819","url":null,"abstract":"The authors analyzed the electroencephalogram (EEG) time series data of a subject under general anesthesia using a newly devised method proposed by the authors. The analysis revealed an exponential characteristic in power spectral density (PSD) of the EEG, known to be peculiar to nonlinear phenomena. In addition, powers of such frequency components in EEG as alpha, beta, theta and delta were calculated quantitatively by integrating the PSD obtained from the segments of the EEG without any filtering procedures, and their temporal variations were investigated in detail. They were remarkably influenced by the stage of anesthesia. Further, the magnitude of the slope of exponentially decaying PSD increased as anesthesia became effective. The authors therefore proposed to take the magnitude as a new measure of estimating brain activities, and its usefulness was confirmed by the fact that the magnitudes for EEGs of children decrease as ages of subject increase.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"357 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115938620","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.950168
S. Burykh, A. Chkeif, K. Abed-Meraim
This work deals with the problem of signal reception in code division multiple access (CDMA) systems. We present an adaptive detector for multipath CDMA channels which mitigates the effects of multipath propagation (interchip and intersymbol interference) and multiple-access interference. It can be suitably implemented in mobile terminals of the CDMA systems due to its low complexity and single-user structure. The proposed detector can be viewed as an efficient adaptive implementation of the batch-processing subspace-based method proposed by Torlak and Xu (see IEEE Trans. on SP, vol.45, no.1, p.137-47, 1997). In this work, we also give the theoretical and experimental justification of the robustness of the method against channel order overestimation errors.
{"title":"Subspace-based blind detection for multipath CDMA: an efficient adaptive implementation","authors":"S. Burykh, A. Chkeif, K. Abed-Meraim","doi":"10.1109/ISSPA.2001.950168","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.950168","url":null,"abstract":"This work deals with the problem of signal reception in code division multiple access (CDMA) systems. We present an adaptive detector for multipath CDMA channels which mitigates the effects of multipath propagation (interchip and intersymbol interference) and multiple-access interference. It can be suitably implemented in mobile terminals of the CDMA systems due to its low complexity and single-user structure. The proposed detector can be viewed as an efficient adaptive implementation of the batch-processing subspace-based method proposed by Torlak and Xu (see IEEE Trans. on SP, vol.45, no.1, p.137-47, 1997). In this work, we also give the theoretical and experimental justification of the robustness of the method against channel order overestimation errors.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132510928","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949854
L. Bouillaut, M. Sidahmed
We show that a nonstationary approach can be preferred to a nonlinear one for the study of some nonlinear phenomena. We prove that the spectral correlation could detect and determine precisely a nonlinear phenomenon. Moreover, in terms of diagnosis on helicopter gearboxes (known for their strong nonlinearity), this tool is much more efficient than the bispectrum. Finally, we introduce an algorithm determining the main nature of a nonlinear cyclic phenomenon. This process is based on the use of higher order cyclic statistics.
{"title":"Helicopter gearbox vibrations: cyclostationary analysis or bilinear approach?","authors":"L. Bouillaut, M. Sidahmed","doi":"10.1109/ISSPA.2001.949854","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949854","url":null,"abstract":"We show that a nonstationary approach can be preferred to a nonlinear one for the study of some nonlinear phenomena. We prove that the spectral correlation could detect and determine precisely a nonlinear phenomenon. Moreover, in terms of diagnosis on helicopter gearboxes (known for their strong nonlinearity), this tool is much more efficient than the bispectrum. Finally, we introduce an algorithm determining the main nature of a nonlinear cyclic phenomenon. This process is based on the use of higher order cyclic statistics.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134589555","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.950214
F. Abdelkefi, P. Duhamel, F. Alberge
This paper presents an elegant solution to impulse noise cancellation in OFDM systems. A parallel between Reed Solomon codes in the complex field and multicarrier transmission using OFDM is first presented. This shows that when the signal is sent over some channel composed of Gaussian plus impulse noise, the impulse noise can be removed by a procedure similar to channel decoding, using information carried by the "syndrome". These results are first derived in a simple situation (oversampled DMT, additive channel), which is merely of theoretical interest. In any case consecutive zeroes, in the output of the OFDM modulator, do not correspond to real subcarriers. However in many cases, pilot tones are emitted for synchronization or channel estimation purposes. These pilot tones are generally scattered among the information ones. Our approach is to use these pilot tones as "syndromes", in order to correct impulse noise. We show that the correction capacity is conditioned by the position of these pilot tones in the emitted sequence. Efficiency of this technique is corroborated with simulation in the practical context of the Hiperlan2.
{"title":"On the use of pilot tones for impulse noise cancellation in Hiperlan2","authors":"F. Abdelkefi, P. Duhamel, F. Alberge","doi":"10.1109/ISSPA.2001.950214","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.950214","url":null,"abstract":"This paper presents an elegant solution to impulse noise cancellation in OFDM systems. A parallel between Reed Solomon codes in the complex field and multicarrier transmission using OFDM is first presented. This shows that when the signal is sent over some channel composed of Gaussian plus impulse noise, the impulse noise can be removed by a procedure similar to channel decoding, using information carried by the \"syndrome\". These results are first derived in a simple situation (oversampled DMT, additive channel), which is merely of theoretical interest. In any case consecutive zeroes, in the output of the OFDM modulator, do not correspond to real subcarriers. However in many cases, pilot tones are emitted for synchronization or channel estimation purposes. These pilot tones are generally scattered among the information ones. Our approach is to use these pilot tones as \"syndromes\", in order to correct impulse noise. We show that the correction capacity is conditioned by the position of these pilot tones in the emitted sequence. Efficiency of this technique is corroborated with simulation in the practical context of the Hiperlan2.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"92 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131249649","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949785
How Sun Dee, V. Jeoti
We propose an approximate fast Hartley transform (FHT) based method to compute the discrete Fourier transform (DFT) coefficients approximately. The approximate FHT is implemented using a periodic discrete wavelet transform (DWT). We find that the proposed method is computationally superior to both the radix 2 fast Fourier transform (FFT) and also the radix 2 approximate FFT algorithms.
{"title":"Computing DFT using approximate fast Hartley transform","authors":"How Sun Dee, V. Jeoti","doi":"10.1109/ISSPA.2001.949785","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949785","url":null,"abstract":"We propose an approximate fast Hartley transform (FHT) based method to compute the discrete Fourier transform (DFT) coefficients approximately. The approximate FHT is implemented using a periodic discrete wavelet transform (DWT). We find that the proposed method is computationally superior to both the radix 2 fast Fourier transform (FFT) and also the radix 2 approximate FFT algorithms.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133056512","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949850
E. Dunstone
There are a number of emerging developments that are important to the continued commercial growth of the biometrics industry. These are altering the way biometrics is perceived by both the general public and by business users. In particular, it is forcing a level of professionalism and transparency in an industry that, in the past, has often operated in a relatively sheltered environment. This paper explores some of the recent policy, standards and research developments in biometrics. The main finding of the paper is that while the biometric industry has moved forward significantly in recent years, there remain major gaps to be filled before business users will widely deploy biometrics solutions.
{"title":"Emerging biometric developments: identifying the missing pieces for industry","authors":"E. Dunstone","doi":"10.1109/ISSPA.2001.949850","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949850","url":null,"abstract":"There are a number of emerging developments that are important to the continued commercial growth of the biometrics industry. These are altering the way biometrics is perceived by both the general public and by business users. In particular, it is forcing a level of professionalism and transparency in an industry that, in the past, has often operated in a relatively sheltered environment. This paper explores some of the recent policy, standards and research developments in biometrics. The main finding of the paper is that while the biometric industry has moved forward significantly in recent years, there remain major gaps to be filled before business users will widely deploy biometrics solutions.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133353073","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.950234
M. Katagiri, Y. Tuzuki, M. Kitaichi, S. Sawamura, Y. Aoki
Defined as the ability to integrate with three-dimensional, interactive, computer-generated environments, the technology of computer graphics (CG) has proven to be a valuable tool for a broad variety of fields, including nuclear engineering. As the application of CG to nuclear engineering, this study proposed a display system in which the health risks from ionizing particles were visualized by CG. The user can see the risk information of the specified organs using the organ select panel in the input part as well as that of the whole body and radiation distribution. The system uses a server and client system and consists of three parts in the server, the simulation part, the visualization part and the database, and the input-output part in the client. The system is useful for a broad range of activities including radiation protection, radiation management, nondestructive assay, waste management, dose minimization, space exploration and medical imaging.
{"title":"A display system for health risks from radiation visualized by CG technology","authors":"M. Katagiri, Y. Tuzuki, M. Kitaichi, S. Sawamura, Y. Aoki","doi":"10.1109/ISSPA.2001.950234","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.950234","url":null,"abstract":"Defined as the ability to integrate with three-dimensional, interactive, computer-generated environments, the technology of computer graphics (CG) has proven to be a valuable tool for a broad variety of fields, including nuclear engineering. As the application of CG to nuclear engineering, this study proposed a display system in which the health risks from ionizing particles were visualized by CG. The user can see the risk information of the specified organs using the organ select panel in the input part as well as that of the whole body and radiation distribution. The system uses a server and client system and consists of three parts in the server, the simulation part, the visualization part and the database, and the input-output part in the client. The system is useful for a broad range of activities including radiation protection, radiation management, nondestructive assay, waste management, dose minimization, space exploration and medical imaging.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133663359","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}
Pub Date : 1900-01-01DOI: 10.1109/ISSPA.2001.949775
G. Sainarayanan, R. Nagarajan, S. Yaacob
This paper focuses on the implementation of certain human vision properties in the real time image processing for vision substitution by acoustic transform of visual information. An experimental prototype has been developed with vision sensor fixed in a headgear and stereo earphone and a laptop computer interconnected. Captured image from vision sensor is processed and transformed into a stereo sound through the earphone. The image processing is critically designed as a model of human vision. It involves edge detection, background suppression, normalization and stepped weightage. The scheme is tested with a blind volunteer and his suggestions in formatting the sound pattern are considered. The software module suits most of the commercially available vision sensors.
{"title":"Incorporating certain human vision properties in vision substitution by stereo acoustic transform","authors":"G. Sainarayanan, R. Nagarajan, S. Yaacob","doi":"10.1109/ISSPA.2001.949775","DOIUrl":"https://doi.org/10.1109/ISSPA.2001.949775","url":null,"abstract":"This paper focuses on the implementation of certain human vision properties in the real time image processing for vision substitution by acoustic transform of visual information. An experimental prototype has been developed with vision sensor fixed in a headgear and stereo earphone and a laptop computer interconnected. Captured image from vision sensor is processed and transformed into a stereo sound through the earphone. The image processing is critically designed as a model of human vision. It involves edge detection, background suppression, normalization and stepped weightage. The scheme is tested with a blind volunteer and his suggestions in formatting the sound pattern are considered. The software module suits most of the commercially available vision sensors.","PeriodicalId":236050,"journal":{"name":"Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133108915","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：