Pub Date : 2004-11-07DOI: 10.1109/ACSSC.2004.1399201
M. Sawides, B. V. Vijaya Kumar, P. Khosla
This paper addresses how to efficiently select which training images to use from an enrollment video sequence to train a correlation filter based face recognition system. Efficient enrollment and the selective use of training images from a video sequence of face images is a very vital component that determines the success of any face recognition system. We describe an efficient boosting algorithm for synthesizing a minimal set of filters that capture the different facial variations during the enrollment phase such that the resulting filter bank can also maintain good generalization and discrimination for recognition and verification. This is done by determining a fitness metric for each filter that determines the amount of facial variation capacity represented by that filter. If that capacity is exceeded by using more training images than needed for that filter then the resulting filter quality is compromised and discrimination performance can degrade leading to lower acceptance and rejection rates. We use advanced correlation filters that have shown to exhibit built-in illumination tolerance.
{"title":"Efficient boosting for synthesizing a minimally compact reduced complexity correlation filter bank for biometric identification","authors":"M. Sawides, B. V. Vijaya Kumar, P. Khosla","doi":"10.1109/ACSSC.2004.1399201","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399201","url":null,"abstract":"This paper addresses how to efficiently select which training images to use from an enrollment video sequence to train a correlation filter based face recognition system. Efficient enrollment and the selective use of training images from a video sequence of face images is a very vital component that determines the success of any face recognition system. We describe an efficient boosting algorithm for synthesizing a minimal set of filters that capture the different facial variations during the enrollment phase such that the resulting filter bank can also maintain good generalization and discrimination for recognition and verification. This is done by determining a fitness metric for each filter that determines the amount of facial variation capacity represented by that filter. If that capacity is exceeded by using more training images than needed for that filter then the resulting filter quality is compromised and discrimination performance can degrade leading to lower acceptance and rejection rates. We use advanced correlation filters that have shown to exhibit built-in illumination tolerance.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116847491","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399513
Zongwang Li, B. Kumar
We present a new class of quasi-cyclic low density parity check (QC-LDPC) codes, whose quasi-cyclic nature makes them attractive for implementation. Both regular and irregular QC-LDPC codes are designed by modifying the progressive edge growth (PEG) graph with a quasi-cyclic constraint. Simulations show that these QC-LDPC codes offer hardware-friendly parity check matrices and have as good error correction performance as random LDPC codes and other good QC-LDPC codes. In addition, the proposed QC-LDPC codes offer a much more flexible set of parameters compared to the traditional designs.
{"title":"A class of good quasi-cyclic low-density parity check codes based on progressive edge growth graph","authors":"Zongwang Li, B. Kumar","doi":"10.1109/ACSSC.2004.1399513","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399513","url":null,"abstract":"We present a new class of quasi-cyclic low density parity check (QC-LDPC) codes, whose quasi-cyclic nature makes them attractive for implementation. Both regular and irregular QC-LDPC codes are designed by modifying the progressive edge growth (PEG) graph with a quasi-cyclic constraint. Simulations show that these QC-LDPC codes offer hardware-friendly parity check matrices and have as good error correction performance as random LDPC codes and other good QC-LDPC codes. In addition, the proposed QC-LDPC codes offer a much more flexible set of parameters compared to the traditional designs.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128699201","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399270
R. Mudumbai, G. Barriac, Upamanyu Madhow
Communication is widely acknowledged as a fundamental bottleneck in sensor networks with large numbers of low-cost, low-power nodes. We consider cooperative transmission of a common message signal from a cluster of sensor nodes to a remote receiver, under realistic transmission models accounting for timing and frequency synchronization offsets across the nodes. The purpose is to obtain range extension by combining the powers of the nodes in a cluster and to obtain robustness against channel impairments by exploiting the diversity naturally arising from the spatial distribution of the sensor nodes. For a simple scheme in which all nodes asynchronously transmit the same signal, we analyze the available diversity gains using an information theoretic analysis of outage capacity for wideband systems. We show that standard modulation formats can be adapted to realize diversity gains in the presence of synchronization errors. We propose simple receiver architectures that realize diversity gains and have desirable scaling properties as the number of sensors increases.
{"title":"Spread-spectrum techniques for distributed space-time communication in sensor networks","authors":"R. Mudumbai, G. Barriac, Upamanyu Madhow","doi":"10.1109/ACSSC.2004.1399270","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399270","url":null,"abstract":"Communication is widely acknowledged as a fundamental bottleneck in sensor networks with large numbers of low-cost, low-power nodes. We consider cooperative transmission of a common message signal from a cluster of sensor nodes to a remote receiver, under realistic transmission models accounting for timing and frequency synchronization offsets across the nodes. The purpose is to obtain range extension by combining the powers of the nodes in a cluster and to obtain robustness against channel impairments by exploiting the diversity naturally arising from the spatial distribution of the sensor nodes. For a simple scheme in which all nodes asynchronously transmit the same signal, we analyze the available diversity gains using an information theoretic analysis of outage capacity for wideband systems. We show that standard modulation formats can be adapted to realize diversity gains in the presence of synchronization errors. We propose simple receiver architectures that realize diversity gains and have desirable scaling properties as the number of sensors increases.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129280225","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399551
G. Stephen, R. Stewart
The cascaded integrator comb filter is commonly used as a first stage decimation filter in communications systems. This paper reviews sharpening techniques for correcting the passband 'droop' present in the frequency response of these filters. A variation on an existing technique that would allow a partially non-recursive (and, therefore, potentially higher speed) implementation is presented for CIC filters with power of two decimation ratios.
{"title":"Sharpening of partially non-recursive CIC decimation filters","authors":"G. Stephen, R. Stewart","doi":"10.1109/ACSSC.2004.1399551","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399551","url":null,"abstract":"The cascaded integrator comb filter is commonly used as a first stage decimation filter in communications systems. This paper reviews sharpening techniques for correcting the passband 'droop' present in the frequency response of these filters. A variation on an existing technique that would allow a partially non-recursive (and, therefore, potentially higher speed) implementation is presented for CIC filters with power of two decimation ratios.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124760276","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399185
G. Wang
Multiplication is a very important operation in digital computing systems. Both signed and unsigned multiplications are required in many computing applications. A unified implementation of signed/unsigned multiplier using redundant binary number representations is proposed in this paper.
{"title":"A unified unsigned/signed binary multiplier","authors":"G. Wang","doi":"10.1109/ACSSC.2004.1399185","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399185","url":null,"abstract":"Multiplication is a very important operation in digital computing systems. Both signed and unsigned multiplications are required in many computing applications. A unified implementation of signed/unsigned multiplier using redundant binary number representations is proposed in this paper.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130328417","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399166
A. E. Ertan, T. Barnwell
Previously, we introduced a windowless linear-prediction method known as circular linear prediction (CLP) modeling for pitch-synchronous analysis of the speech spectrum and presented its spectral modeling properties using synthetic speech signals. In this paper, we discuss how the CLP method and its multicycle generalization can be used with real speech signals. We also present the CLP methods' spectral estimation performance using real speech. As was the case for synthetic speech, these experiments proved that the CLP method has superior spectral estimation accuracy at onsets and has similar estimation performance to the autocorrelation method in stationary regions. We also observed that the multicycle generalization of the CLP method is required for partially-voiced regions.
{"title":"Spectral estimation performance of circular linear prediction modeling for real-speech signals","authors":"A. E. Ertan, T. Barnwell","doi":"10.1109/ACSSC.2004.1399166","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399166","url":null,"abstract":"Previously, we introduced a windowless linear-prediction method known as circular linear prediction (CLP) modeling for pitch-synchronous analysis of the speech spectrum and presented its spectral modeling properties using synthetic speech signals. In this paper, we discuss how the CLP method and its multicycle generalization can be used with real speech signals. We also present the CLP methods' spectral estimation performance using real speech. As was the case for synthetic speech, these experiments proved that the CLP method has superior spectral estimation accuracy at onsets and has similar estimation performance to the autocorrelation method in stationary regions. We also observed that the multicycle generalization of the CLP method is required for partially-voiced regions.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126756412","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399255
K. Pun, T.Q. Nguyen
In this paper, we propose to study the relationship between filter banks (FB) and real space time block codes (STBC). From the FB perspective, in order to decode the symbol, we will show that the corresponding FB must have perfect reconstruction (PR) property. Then we consider the problem of implementing a nonrate-one code where its entries may contain algebraic number. In order to reduce the complexity, we propose a method to approximate this STBC using finite word length while preserving the orthogonality condition.
{"title":"Real-orthogonal STBC representation using filter banks","authors":"K. Pun, T.Q. Nguyen","doi":"10.1109/ACSSC.2004.1399255","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399255","url":null,"abstract":"In this paper, we propose to study the relationship between filter banks (FB) and real space time block codes (STBC). From the FB perspective, in order to decode the symbol, we will show that the corresponding FB must have perfect reconstruction (PR) property. Then we consider the problem of implementing a nonrate-one code where its entries may contain algebraic number. In order to reduce the complexity, we propose a method to approximate this STBC using finite word length while preserving the orthogonality condition.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124154689","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399548
M. Gupta, Balu Santhanam
ICA based blind source separation methods suffer from inherent scaling and permutation ambiguities , which would cause problems in a DS-CDMA multiuser detection and MAI mitigation scenario. Recently ICA methods incorporating prior information about the desired user's code were proposed as an add-on to the subspace MMSE detector. In this paper, we propose a Q-R decomposition based technique to initialize the ICA algorithm in order to remove the permutation ambiguity as well as to avoid the explicit subspace computations. It is shown via simulations that the proposed technique is more robust in the case of highly correlated unequal energy users.
{"title":"Prior ICA based blind multiuser detection in DS-CDMA systems","authors":"M. Gupta, Balu Santhanam","doi":"10.1109/ACSSC.2004.1399548","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399548","url":null,"abstract":"ICA based blind source separation methods suffer from inherent scaling and permutation ambiguities , which would cause problems in a DS-CDMA multiuser detection and MAI mitigation scenario. Recently ICA methods incorporating prior information about the desired user's code were proposed as an add-on to the subspace MMSE detector. In this paper, we propose a Q-R decomposition based technique to initialize the ICA algorithm in order to remove the permutation ambiguity as well as to avoid the explicit subspace computations. It is shown via simulations that the proposed technique is more robust in the case of highly correlated unequal energy users.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123372017","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399413
J. Salazar, M. Azimi-Sadjadi
This paper presents a study on an adaptable image retrieval system used for underwater target identification. Shape and textural features extracted from contrast and range electro-optical imagery data are used to represent each mine-like or non-mine-like sample image. The retrieval system is an adaptable two-layer network where the first layer is structurally adaptable in response to relevance feedback from expert users, while the second layer is adaptable only when a new class is introduced. Each node in the second layer represents one sample image in the training database. Test results on a large electro-optical imagery database are presented, which show the promise of the proposed system as an adaptable image retrieval system.
{"title":"Adaptable image retrieval with application to underwater target identification","authors":"J. Salazar, M. Azimi-Sadjadi","doi":"10.1109/ACSSC.2004.1399413","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399413","url":null,"abstract":"This paper presents a study on an adaptable image retrieval system used for underwater target identification. Shape and textural features extracted from contrast and range electro-optical imagery data are used to represent each mine-like or non-mine-like sample image. The retrieval system is an adaptable two-layer network where the first layer is structurally adaptable in response to relevance feedback from expert users, while the second layer is adaptable only when a new class is introduced. Each node in the second layer represents one sample image in the training database. Test results on a large electro-optical imagery database are presented, which show the promise of the proposed system as an adaptable image retrieval system.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116317156","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399124
H. Laamari, J. Belfiore, N. Ibrahim
In this paper a maximum likelihood detection problem for a digital communication system is reformulated as a semidefinite programming (SDP) problem. A relaxation of this problem is done. An interior point method will be used to efficiently solve the semidefinite program arising from the relaxation. From the solution given by this interior point method, an approximate of the solution of the initial ML detection problem will be extracted using a randomization method. The detection method presented in this paper will have near ML performances with a polynomial complexity.
{"title":"Near maximum likelihood detection using an interior point method and semidefinite programming","authors":"H. Laamari, J. Belfiore, N. Ibrahim","doi":"10.1109/ACSSC.2004.1399124","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399124","url":null,"abstract":"In this paper a maximum likelihood detection problem for a digital communication system is reformulated as a semidefinite programming (SDP) problem. A relaxation of this problem is done. An interior point method will be used to efficiently solve the semidefinite program arising from the relaxation. From the solution given by this interior point method, an approximate of the solution of the initial ML detection problem will be extracted using a randomization method. The detection method presented in this paper will have near ML performances with a polynomial complexity.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"610 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116467745","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}
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