Pub Date : 1999-08-22DOI: 10.1109/PACRIM.1999.799601
X.F. Wang, W. Lu, A. Antoniou
Several design criteria for time-domain equalization in discrete-multitone-based asymmetric digital subscriber line systems are studied. A new criterion that maximizes the signal-to-noise ratio regardless of the profile of bandwidth occupancy is proposed. Based on the new criterion, a procedure for optimizing the bandwidth occupancy is developed. The new criterion is shown to track the change in bandwidth occupancy and thus leads to significant performance gain when combined with bandwidth optimization. Simulations are carried out to quantify the effects of the new criterion and its associated bandwidth optimization on the performance of the system.
{"title":"Equalization for partially bandwidth-occupied multicarrier transceivers","authors":"X.F. Wang, W. Lu, A. Antoniou","doi":"10.1109/PACRIM.1999.799601","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799601","url":null,"abstract":"Several design criteria for time-domain equalization in discrete-multitone-based asymmetric digital subscriber line systems are studied. A new criterion that maximizes the signal-to-noise ratio regardless of the profile of bandwidth occupancy is proposed. Based on the new criterion, a procedure for optimizing the bandwidth occupancy is developed. The new criterion is shown to track the change in bandwidth occupancy and thus leads to significant performance gain when combined with bandwidth optimization. Simulations are carried out to quantify the effects of the new criterion and its associated bandwidth optimization on the performance of the system.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128027117","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799581
Y. Zhang, M. Zeytinoglu
Adaptive block processing is a technique suitable for compressing non-stationary signals, where input blocks are first decomposed by a filterbank into subband signals. These subband signals are in turn analyzed to extract the time-varying signal parameters. We can optimize a given subband coding algorithm by introducing time-varying filterbanks, where for each input block we alter the structure of the decomposition filterbank such that a particular coding criteria is optimized. In this paper, we use time-varying filterbanks as a basis for adaptive subband coding. In particular, we analyze the relationship between adaptive block subband coding and time-varying filterbanks. We introduced a method for deriving boundary filters and entry/exit filters for the synthesis filterbanks. We show that conventional design techniques for the time-varying filterbanks exhibit many characteristics that make them less than ideal candidates for adaptive signal decomposition.
{"title":"Block subband coding and time-varying filterbanks","authors":"Y. Zhang, M. Zeytinoglu","doi":"10.1109/PACRIM.1999.799581","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799581","url":null,"abstract":"Adaptive block processing is a technique suitable for compressing non-stationary signals, where input blocks are first decomposed by a filterbank into subband signals. These subband signals are in turn analyzed to extract the time-varying signal parameters. We can optimize a given subband coding algorithm by introducing time-varying filterbanks, where for each input block we alter the structure of the decomposition filterbank such that a particular coding criteria is optimized. In this paper, we use time-varying filterbanks as a basis for adaptive subband coding. In particular, we analyze the relationship between adaptive block subband coding and time-varying filterbanks. We introduced a method for deriving boundary filters and entry/exit filters for the synthesis filterbanks. We show that conventional design techniques for the time-varying filterbanks exhibit many characteristics that make them less than ideal candidates for adaptive signal decomposition.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121839927","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799511
M. Ahmed, R. Ward
We introduce an expert system for the recognition of any typed or handwritten symbols, then, we describe how a symbol can be represented by another symbol which is formed of only straight line segments. This allows a large number of different styles of handwritten or typed symbols to be mapped into a much smaller number of representations. These representations are used as models for the automatic recognition of symbols. The system uses the structural pattern recognition technique for modeling symbols by a set of straight lines referred to as line segments. The system rotates, scales and thins the symbol, then extracts the symbol strokes. Each stroke is then mapped into line segments. The system is shown to be able to map similar styles of the symbol to the same representation. When the system had some stored models for each symbol (an average of 97 models/symbol), the recognition rate was 95%, and the rejection rate was 16.1%. The system was tested by 5726 handwritten English characters from the Center of Excellence for Document Analysis and Recognition (CEDAR) database.
{"title":"A novel intelligent system for defining similar symbols","authors":"M. Ahmed, R. Ward","doi":"10.1109/PACRIM.1999.799511","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799511","url":null,"abstract":"We introduce an expert system for the recognition of any typed or handwritten symbols, then, we describe how a symbol can be represented by another symbol which is formed of only straight line segments. This allows a large number of different styles of handwritten or typed symbols to be mapped into a much smaller number of representations. These representations are used as models for the automatic recognition of symbols. The system uses the structural pattern recognition technique for modeling symbols by a set of straight lines referred to as line segments. The system rotates, scales and thins the symbol, then extracts the symbol strokes. Each stroke is then mapped into line segments. The system is shown to be able to map similar styles of the symbol to the same representation. When the system had some stored models for each symbol (an average of 97 models/symbol), the recognition rate was 95%, and the rejection rate was 16.1%. The system was tested by 5726 handwritten English characters from the Center of Excellence for Document Analysis and Recognition (CEDAR) database.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121945671","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799527
K. Katagishi, T. Asami, Y. Ebihara, T. Sugiyama, K. Toraichi
When sending corporate secrets by electronic mail (e-mail), care must be taken to protect the security of the information against the various kinds of illicit manipulation that can occur on the Internet. We have developed a security enhanced mail gateway (SEMAIL) that ensures the privacy of e-mail messages without requiring users to install new software or learn complicated operating procedures. The SEMAIL system, in which an encryption program PGP (Pretty Good Privacy) is used, is available for both POP3-based Unix mails and PC-LAN-based ones.
当通过电子邮件(e-mail)发送公司机密时，必须注意保护信息的安全性，防止互联网上可能发生的各种非法操作。我们开发了一种增强安全的邮件网关(SEMAIL)，可确保电子邮件信息的隐私，而无需用户安装新软件或学习复杂的操作程序。SEMAIL系统使用了加密程序PGP (Pretty Good Privacy)，它既可用于基于pop3的Unix邮件，也可用于基于pc - lan的邮件。
{"title":"A public key cryptography-based security enhanced mail gateway with the mailing list function","authors":"K. Katagishi, T. Asami, Y. Ebihara, T. Sugiyama, K. Toraichi","doi":"10.1109/PACRIM.1999.799527","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799527","url":null,"abstract":"When sending corporate secrets by electronic mail (e-mail), care must be taken to protect the security of the information against the various kinds of illicit manipulation that can occur on the Internet. We have developed a security enhanced mail gateway (SEMAIL) that ensures the privacy of e-mail messages without requiring users to install new software or learn complicated operating procedures. The SEMAIL system, in which an encryption program PGP (Pretty Good Privacy) is used, is available for both POP3-based Unix mails and PC-LAN-based ones.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115999693","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799585
J. Monera-Llorca, W. Lu, V. Bhargava
A wavelet-packet-based family of user signatures for asynchronous CDMA systems is investigated. These signatures are of non-binary nature and are generated by the application of the inverse wavelet packet transform. Through numerical optimization, we obtain the wavelet filter which minimizes the crosscorrelation among signatures for different user configuration systems. The improvement in performance is especially notable in the oversaturated system scenario. Finally, we comment briefly on the topics of bandwidth efficiency, user privacy, and implementation.
{"title":"Wavelet-packet-based signatures for asynchronous CDMA systems","authors":"J. Monera-Llorca, W. Lu, V. Bhargava","doi":"10.1109/PACRIM.1999.799585","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799585","url":null,"abstract":"A wavelet-packet-based family of user signatures for asynchronous CDMA systems is investigated. These signatures are of non-binary nature and are generated by the application of the inverse wavelet packet transform. Through numerical optimization, we obtain the wavelet filter which minimizes the crosscorrelation among signatures for different user configuration systems. The improvement in performance is especially notable in the oversaturated system scenario. Finally, we comment briefly on the topics of bandwidth efficiency, user privacy, and implementation.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"52 194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126721517","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799548
Chen Chau Chu, H. Alnuweiri
This paper proposes a multicast packet switching architecture that employs input/output buffers, and internal bandwidth expansion to reduce blocking substantially. Internal buffers enhance switch robustness under transient bursty traffic conditions. The switch regulates packet loss and delay using link-capacity back-pressure in conjunction with dynamic random early detection (or D-RED) algorithm. Because of these features the proposed switch exhibits excellent performance under multicast (as well as unicast) traffic even under heavy bursty traffic loads. Simulation studies show that the proposed architecture with its enhanced flow control features has superior packet loss performance compared to many other switch classes especially under multicast and bursty traffic.
{"title":"Performance evaluation of a multicast packet switch employing dynamic random early detection","authors":"Chen Chau Chu, H. Alnuweiri","doi":"10.1109/PACRIM.1999.799548","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799548","url":null,"abstract":"This paper proposes a multicast packet switching architecture that employs input/output buffers, and internal bandwidth expansion to reduce blocking substantially. Internal buffers enhance switch robustness under transient bursty traffic conditions. The switch regulates packet loss and delay using link-capacity back-pressure in conjunction with dynamic random early detection (or D-RED) algorithm. Because of these features the proposed switch exhibits excellent performance under multicast (as well as unicast) traffic even under heavy bursty traffic loads. Simulation studies show that the proposed architecture with its enhanced flow control features has superior packet loss performance compared to many other switch classes especially under multicast and bursty traffic.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133215409","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799473
T. Yoshikawa, T. Tabe, R. Kishinami, H. Matsuda, A. Hashimoto
A molecular phylogenetic tree is a tree-structured graph that represents the evolutionary process of genes, and is constructed from sequence data (such as DNA sequences) obtained from several organisms. Although molecular phylogenetic trees are fundamental data structures in evolutionary analysis, no database system is available that can match trees in the database against a user-supplied tree by comparing tree structures. In this paper, we propose a phylogenetic tree database system with a retrieval function that matches trees having similar structure. The tree data stored in the database are transformed from document images published in biological journals using a pattern-recognition program developed by us. To retrieve phylogenetic trees from the database according to their structures, we propose a method of determining the structural similarity between trees that is based on the split distance method. Our structural similarity measure shows high correlation with the log-likelihood difference that is widely used for comparing phylogenetic trees, and the computation time of our measure is much shorter than that of the log-likelihood difference, which relies on sequence comparison.
{"title":"On the implementation of a phylogenetic tree database","authors":"T. Yoshikawa, T. Tabe, R. Kishinami, H. Matsuda, A. Hashimoto","doi":"10.1109/PACRIM.1999.799473","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799473","url":null,"abstract":"A molecular phylogenetic tree is a tree-structured graph that represents the evolutionary process of genes, and is constructed from sequence data (such as DNA sequences) obtained from several organisms. Although molecular phylogenetic trees are fundamental data structures in evolutionary analysis, no database system is available that can match trees in the database against a user-supplied tree by comparing tree structures. In this paper, we propose a phylogenetic tree database system with a retrieval function that matches trees having similar structure. The tree data stored in the database are transformed from document images published in biological journals using a pattern-recognition program developed by us. To retrieve phylogenetic trees from the database according to their structures, we propose a method of determining the structural similarity between trees that is based on the split distance method. Our structural similarity measure shows high correlation with the log-likelihood difference that is widely used for comparing phylogenetic trees, and the computation time of our measure is much shorter than that of the log-likelihood difference, which relies on sequence comparison.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133248202","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799553
M. Lozano, I. Ramos
The object oriented paradigm is considered as one of the best approaches for systems development. There exists many models, techniques and tools developed following this paradigm. Nevertheless, most of the object-oriented techniques used in the development of systems does not take into account human-computer interaction issues. This is a very important aspect that must be tackled in order to correctly fulfil the user needs and requirements. The main purpose of this paper is to present an object oriented approach for the integration of a user model in an object oriented software production environment.
{"title":"An object oriented approach for the specification of user interfaces","authors":"M. Lozano, I. Ramos","doi":"10.1109/PACRIM.1999.799553","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799553","url":null,"abstract":"The object oriented paradigm is considered as one of the best approaches for systems development. There exists many models, techniques and tools developed following this paradigm. Nevertheless, most of the object-oriented techniques used in the development of systems does not take into account human-computer interaction issues. This is a very important aspect that must be tackled in order to correctly fulfil the user needs and requirements. The main purpose of this paper is to present an object oriented approach for the integration of a user model in an object oriented software production environment.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133254215","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799586
S. Park, I. Song, Jooshik Lee, Seong-Ro Lee
Direct sequence code division multiple access (DS-CDMA) communication systems using random polyphase sequences with coherent reception in multipath fading channels are considered. By examining the asymptotic characteristics of the multiple access interference and multipath interference, we show that the DS-CDMA system performance with random m/sub p/-phase sequences of m/sub p//spl ges/3 is better than that with random binary sequences in multipath fading environment.
{"title":"DS-CDMA systems with polyphase signature sequences in multipath fading channel","authors":"S. Park, I. Song, Jooshik Lee, Seong-Ro Lee","doi":"10.1109/PACRIM.1999.799586","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799586","url":null,"abstract":"Direct sequence code division multiple access (DS-CDMA) communication systems using random polyphase sequences with coherent reception in multipath fading channels are considered. By examining the asymptotic characteristics of the multiple access interference and multipath interference, we show that the DS-CDMA system performance with random m/sub p/-phase sequences of m/sub p//spl ges/3 is better than that with random binary sequences in multipath fading environment.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133354388","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 : 1999-08-22DOI: 10.1109/PACRIM.1999.799567
Chang Nian Zhang, Ming Zhao, M. Wang
This paper focuses on phase analysis to explore the potential of single neuron local arithmetic and logic operations on input conductances. The analysis is based on a rational function model of local spatial summation with the equivalent circuits for steady-state membrane potentials. The prototypes of arithmetic and logic operations are then constructed with their input and output range.
{"title":"Multi-mode single neuron arithmetics and logics","authors":"Chang Nian Zhang, Ming Zhao, M. Wang","doi":"10.1109/PACRIM.1999.799567","DOIUrl":"https://doi.org/10.1109/PACRIM.1999.799567","url":null,"abstract":"This paper focuses on phase analysis to explore the potential of single neuron local arithmetic and logic operations on input conductances. The analysis is based on a rational function model of local spatial summation with the equivalent circuits for steady-state membrane potentials. The prototypes of arithmetic and logic operations are then constructed with their input and output range.","PeriodicalId":176763,"journal":{"name":"1999 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117159281","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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